NATIONAL INSTITUTES OF HEALTH
This primer presents background information on stem cells. It includes an explanation of what stem cells are; what pluripotent stem cells are; how pluripotent stem cells are derived; why pluripotent stem cells are important to science; why they hold such great promise for advances in health care; and what adult stem cells are.
Recent published reports on the isolation and successful culturing of the first human pluripotent stem cell lines have generated great excitement and have brought biomedical research to the edge of a new frontier. The development of these human pluripotent stem cell lines deserves close scientific examination, evaluation of the promise for new therapies, and prevention strategies, and open discussion of the ethical issues.
In order to understand the importance of this discovery as well as the related scientific, medical, and ethical issues, it is absolutely essential to first clarify the terms and definitions.
What is a stem cell?
Stem cells have the ability to divide for indefinite periods in culture and to give rise to specialized cells. They are best described in the context of normal human development. Human development begins when a sperm fertilizes an egg and creates a single cell that has the potential to form an entire organism. This fertilized egg is totipotent, meaning that its potential is total. In the first hours after fertilization, this cell divides into identical totipotent cells. (Figure I) This means that either one of these cells, if placed into a woman's uterus, has the potential to develop into a fetus. In fact, identical twins develop when two totipotent cells separate and develop into two individual, genetically identical human beings. Approximately four days after fertilization and after several cycles of cell division, these totipotent cells begin to specialize, forming a hollow sphere of cells, called a blastocyst. The blastocyst has an outer layer of cells and inside the hollow sphere, there is a cluster of cells called the inner cell mass.
The outer layer of cells will go on to form the placenta and other supporting tissues needed for fetal development in the uterus. The inner cell mass cells will go on to form virtually all of the tissues of the human body. Although the inner cell mass cells can form virtually every type of cell found in the human body, they cannot form an organism because they are unable to give rise to the placenta and supporting tissues necessary for development in the human uterus. These inner cell mass cells are pluripotent — they can give rise to many types of cells but not all types of cells necessary for fetal development. Because their potential is not total, they are not totipotent and they are not embryos. In fact, if an inner cell mass cell were placed into a woman's uterus, it would not develop into a fetus.
The pluripotent stem cells undergo further specialization into stem cells that are committed to give rise to cells that have a particular function. Examples of this include blood stem cells which give rise to red blood cells, white blood cells and platelets; and skin stem cells that give rise to the various types of skin cells. These more specialized stem cells are called multipotent. (Figure II)
While stem cells are extraordinarily important in early human development, multipotent stem cells are also found in children and adults. For example, consider one of the best understood stem cells, the blood stem cell. Blood stem cells reside in the bone marrow of every child and adult, and in fact, they can be found in very small numbers circulating in the blood stream. Blood stem cells perform the critical role of continually replenishing our supply of blood cells — red blood cells, white blood cells, and platelets — throughout life. A person cannot survive without blood stem cells.
How are pluripotent stem cells derived?
At present, human pluripotent cell lines have been developed from two sources1 with methods previously developed in work with animal models.
(1) In the work done by Dr. Thomson, pluripotent stem cells were isolated directly from the inner cell mass of human embryos at the blastocyst stage. Dr. Thomson received embryos from IVF (In Vitro Fertilization) clinics-these embryos were in excess of the clinical need for infertility treatment. The embryos were made for purposes of reproduction, not research. Informed consent was obtained from the donor couples. Dr. Thomson isolated the inner cell mass (see Figure III) and cultured these cells producing a pluripotent stem cell line.
(2) In contrast, Dr. Gearhart isolated pluripotent stem cells from fetal tissue obtained from terminated pregnancies. Informed consent was obtained from the donors after they had independently made the decision to terminate their pregnancy. Dr. Gearhart took cells from the region of the fetus that was destined to develop into the testes or the ovaries. Although the cells developed in Dr. Gearhart's lab and Dr. Thomson's lab were derived from different sources, they appear to be very similar. (Figure III)
The use of somatic cell nuclear transfer (SCNT) may be another way that pluripotent stem cells could be isolated. In studies with animals using SCNT, researchers take a normal animal egg cell and remove the nucleus (cell structure containing the chromosomes). The material left behind in the egg cell contains nutrients and other energy-producing materials that are essential for embryo development. Then, using carefully worked out laboratory conditions, a somatic cell - any cell other than an egg or a sperm cell - is placed next to the egg from which the nucleus had been removed, and the two are fused. The resulting fused cell, and its immediate descendants, are believed to have the full potential to develop into an entire animal, and hence are totipotent. As described in Figure I, these totipotent cells will soon form a blastocyst. Cells from the inner cell mass of this blastocyst could, in theory, be used to develop pluripotent stem cell lines. Indeed, any method by which a human blastocyst is formed could potentially serve as a source of human pluripotent stem cells (Figure IV).
Potential Applications of Pluripotent Stem Cells
There are several important reasons why the isolation of human pluripotent stem cells is important to science and to advances in health care (Figure V). At the most fundamental level, pluripotent stem cells could help us to understand the complex events that occur during human development. A primary goal of this work would be the identification of the factors involved in the cellular decision-making process that results in cell specialization. We know that turning genes on and off is central to this process, but we do not know much about these "decision-making" genes or what turns them on or off. Some of our most serious medical conditions, such as cancer and birth defects, are due to abnormal cell specialization and cell division. A better understanding of normal cell processes will allow us to further delineate the fundamental errors that cause these often deadly illnesses.
Human pluripotent stem cell research could also dramatically change the way we develop drugs and test them for safety. For example, new medications could be initially tested using human cell lines. Cell lines are currently used in this way (for example cancer cells). Pluripotent stem cells would allow testing in more cell types. This would not replace testing in whole animals and testing in human beings, but it would streamline the process of drug development. Only the drugs that are both safe and appear to have a beneficial effect in cell line testing would graduate to further testing in laboratory animals and human subjects.
Perhaps the most far-reaching potential application of human pluripotent stem cells is the generation of cells and tissue that could be used for so-called "cell therapies." Many diseases and disorders result from disruption of cellular function or destruction of tissues of the body. Today, donated organs and tissues are often used to replace ailing or destroyed tissue. Unfortunately, the number of people suffering from these disorders far outstrips the number of organs available for transplantation. Pluripotent stem cells, stimulated to develop into specialized cells, offer the possibility of a renewable source of replacement cells and tissue to treat a myriad of diseases, conditions, and disabilities including Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis and rheumatoid arthritis. There is almost no realm of medicine that might not be touched by this innovation. Some details of two of these examples follow.
First, we must do the basic research to understand the cellular events that lead to cell specialization in the human, so that we can direct these pluripotent stem cells to become the type(s) of tissue needed for transplantation.
Second, before we can use these cells for transplantation, we must overcome the well-known problem of immune rejection. Because human pluripotent stem cells derived from embryos or fetal tissue would be genetically different from the recipient, future research would need to focus on modifying human pluripotent stem cells to minimize tissue incompatibility or to create tissue banks with the most common tissue-type profiles.
The use of somatic cell nuclear transfer (SCNT) would be another way to overcome the problem of tissue incompatibility for some patients. For example, consider a person with progressive heart failure. Using SCNT, the nucleus of virtually any somatic cell from that patient could be fused with a donor egg cell from which the nucleus had been removed. With proper stimulation the cell would develop into a blastocyst: cells from the inner cell mass could be taken to create a culture of pluripotent cells. These cells could then be stimulated to develop into heart muscle cells. Because the vast majority of genetic information is contained in the nucleus, these cells would be essentially identical genetically to the person with the failing heart. When these heart muscle cells were transplanted back into the patient, there would likely be no rejection and no need to expose the patient to immune-suppressing drugs, which can have toxic effects.
Adult Stem Cells
As noted earlier, multipotent stem cells can be found in some types of adult tissue. In fact, stem cells are needed to replenish the supply cells in our body that normally wear out. An example, which was mentioned previously, is the blood stem cell.
Multipotent stem cells have not been found for all types of adult tissue, but discoveries in this area of research are increasing. For example, until recently, it was thought that stem cells were not present in the adult nervous system, but, in recent years, neuronal stem cells have been isolated from the rat and mouse nervous systems. The experience in humans is more limited. In humans, neuronal stem cells have been isolated from fetal tissue and a kind of cell that may be a neuronal stem cell has been isolated from adult brain tissue that was surgically removed for the treatment of epilepsy.
Do adult stem cells have the same potential as pluripotent stem cells?
Until recently, there was little evidence in mammals that multipotent cells such as blood stem cells could change course and produce skin cells, liver cells or any cell other than a blood stem cell or a specific type of blood cell; however, research in animals is leading scientists to question this view.
In animals, it has been shown that some adult stem cells previously thought to be committed to the development of one line of specialized cells are able to develop into other types of specialized cells. For example, recent experiments in mice suggest that when neural stem cells were placed into the bone marrow, they appeared to produce a variety of blood cell types. In addition, studies with rats have indicated that stem cells found in the bone marrow were able to produce liver cells. These exciting findings suggest that even after a stem cell has begun to specialize, the stem cell may, under certain conditions, be more flexible than first thought. At this time, demonstration of the flexibility of adult stem cells has been only observed in animals and limited to a few tissue types.
Why not just pursue research with adult stem cells?
Research on human adult stem cells suggests that these multipotent cells have great potential for use in both research and in the development of cell therapies. For example, there would be many advantages to using adult stem cells for transplantation. If we could isolate the adult stem cells from a patient, coax them to divide and direct their specialization and then transplant them back into the patient, it is unlikely that such cells would be rejected. The use of adult stem cells for such cell therapies would certainly reduce or even avoid the practice of using stem cells that were derived from human embryos or human fetal tissue, sources that trouble many people on ethical grounds.
While adult stem cells hold real promise, there are some significant limitations to what we may or may not be able to accomplish with them. First of all, stem cells from adults have not been isolated for all tissues of the body. Although many different kinds of multipotent stem cells have been identified, adult stem cells for all cell and tissue types have not yet been found in the adult human. For example, we have not located adult cardiac stem cells or adult pancreatic islet stem cells in humans.
Secondly, adult stem cells are often present in only minute quantities, are difficult to isolate and purify, and their numbers may decrease with age. For example, brain cells from adults that may be neuronal stem cells have only been obtained by removing a portion of the brain of epileptics, not a trivial procedure.
Any attempt to use stem cells from a patient's own body for treatment would require that stem cells would first have to be isolated from the patient and then grown in culture in sufficient numbers to obtain adequate quantities for treatment. For some acute disorders, there may not be enough time to grow enough cells to use for treatment. In other disorders, caused by a genetic defect, the genetic error would likely be present in the patient's stem cells. Cells from such a patient may not be appropriate for transplantation. There is evidence that stem cells from adults may have not have the same capacity to proliferate as younger cells do. In addition, adult stem cells may contain more DNA abnormalities, caused by exposure to daily living, including sunlight, toxins, and by expected errors made in DNA replication during the course of a lifetime. These potential weaknesses could limit the usefulness of adult stem cells.
Research on the early stages of cell specialization may not be possible with adult stem cells since they appear to be farther along the specialization pathway than pluripotent stem cells. In addition, one adult stem cell line may be able to form several, perhaps 3 or 4, tissue types, but there is no clear evidence that stem cells from adults, human or animal, are pluripotent. In fact, there is no evidence that adult stem cells have the broad potential characteristic of pluripotent stem cells. In order to determine the very best source of many of the specialized cells and tissues of the body for new treatments and even cures, it will be vitally important to study the developmental potential of adult stem cells and compare it to that of pluripotent stem cells.
Given the enormous promise of stem cells to the development of new therapies for the most devastating diseases, it is important to simultaneously pursue all lines of research. Science and scientists need to search for the very best sources of these cells. When they are identified, regardless of their sources, researchers will use them to pursue the development of new cell therapies.
The development of stem cell lines, both pluripotent and multipotent, that may produce many tissues of the human body is an important scientific breakthrough. It is not too unrealistic to say that this research has the potential to revolutionize the practice of medicine and improve the quality and length of life.
DNA - abbreviation for deoxyribonucleic acid which makes up genes.
Gene - a functional unit of heredity which is a segment of DNA located in a specific site on a chromosome. A gene directs the formation of an enzyme or other protein.
Somatic cell - cell of the body other than egg or sperm.
Somatic cell nuclear transfer - the transfer of a cell nucleus from a somatic cell into an egg from which the nucleus has been removed.
Stem cells - cells that have the ability to divide for indefinite periods in culture and to give rise to specialized cells.
Pluripotent -capable of giving rise to most tissues of an organism.
Totipotent - having unlimited
capability. Totipotent cells have the capacity to specialize into extraembryonic
membranes and tissues, the embryo, and all postembryonic tissues and organs.
1 Michael Shamblott, et al, Derivation of pluripotent stem cells from cultured human primordial germ cells. PNAS, 95: 13726-13731, Nov. 1998.
James Thomson, et al, Embryonic stem
cell lines derived from human blastocysts. Science, 282: 1145-1147, Nov.
April 23, 2001
Medical researchers currently are working to unlock the secrets of stem cells — the cells that produce all the different types of cells and tissues that make up your body. Implanting such cells, which would work to replace damaged cells, shows potential value in treating many diseases, perhaps including Parkinson's, diabetes and Alzheimer's.
"The science of stem cell application is very young," says Stanimir Vuk-Pavlovic, Ph.D., a specialist in stem cell research at Mayo Clinic, Rochester, Minn. "Much more research must be done before we fully understand the power of stem cells, but the potential for the future is exciting."
In the beginning
A stem cell produces cells that perform specific functions in your body. It also copies itself (self-replicates).
When a stem cell divides, one of
the resulting cells becomes specialized — it creates certain types of cells
in your body, such as heart or brain cells. The other cell from that division
is an exact copy of the original stem cell. It's available for future division
when repair is needed from daily wear on your body.
Your body contains many types of stem cells. They're referred to as adult stem cells. Adult stem cells reproduce to renew various tissues as needed, such as the 200 billion new red blood cells required by your body each day.
When a stem cell divides, it creates a stem cell that's specialized — one that can create cells that perform specific functions, such as blood cells. It also creates an exact replica of itself.
Actually, the most powerful stem cells, called embryonic stem cells, are found in the very early stages of development. These cells, sometimes referred to as primitive, can become each of the more than 200 cell types in the body.
However, what prompts one embryonic cell to eventually differentiate itself as lung tissue and another as bone remains a frontier for further exploration. The process, known as transdifferentiation, is a key area of interest for many researchers.
"The area of transdifferentiation shows a lot of promise," says Dr. Vuk-Pavlovic. "The changing of direction in cell development — for instance, getting a liver or muscle cell from a cell that would normally make a blood cell — is still very much a mystery. Once we understand the process more fully, we will be able to engineer tissues and organs for use in regenerative medicine."
In hot pursuit
Recent discoveries have scientists more interested than ever in unlocking the mysteries of stem cells.
In 1998, U.S. researchers at the University of Wisconsin, Madison, announced that they'd discovered how to stop human embryonic stem cells from becoming specialized and how to keep them at their maximum potential to differentiate into any cell in the body. This set the stage for research into how to direct these cells — for instance, how to coax them to form a new kidney.
Researchers also are excited about another discovery that displaced long-held beliefs about adult stem cells. Although it generally has been accepted that these cells are committed to producing a particular type of cell — for example, once an adult brain stem cell, always an adult brain stem cell — recent laboratory studies revealed that some adult stem cells can turn into one of several different tissues.
Researchers now hope they can figure out how to direct adult stem cell development toward one type of cell over another. That could mean being able to repair an area in the body with adult stem cells from a different location. For instance, could a damaged kidney be treated using blood stem cells or brain stem cells?
Stem cells in use
The biggest use for stem cells today is in bone marrow transplants. These transplants have been done successfully for more than 30 years.
Bone marrow contains blood-forming stem cells. These cells continuously produce oxygen-carrying red blood cells, white blood cells that help fight infection and platelets that help stop bleeding.
Bone marrow transplants are used to treat people with certain cancers, such as leukemia and lymphoma, and some noncancerous conditions, such as aplastic anemia and some inherited immune disorders. The transplants also are used experimentally in attempts to treat certain cancers, such as breast or testicular cancers.
Traditionally, bone marrow transplants have used the person's own marrow that is removed from bone and frozen. Cancer cells and defective marrow are destroyed by chemotherapy and radiation, and the previously removed marrow is transplanted back into the person. Now, the treatment commonly involves using blood rather than marrow.
In the early 1980s, researchers discovered that stem cells circulate in the bloodstream — they're called peripheral blood stem cells. They're rather scarce in the bloodstream, but their number can be increased by drugs that help stem cells release from bone marrow. Eventually, they're collected from blood and later reintroduced as a "transplant."
The use of a person's own peripheral blood stem cells instead of bone marrow makes transplants safer, particularly for older people.
New bone marrow riches
Another stem cell discovery related to bone marrow has the scientific community buzzing. Researchers announced in 2000 that they'd isolated mesenchymal (mez-ENG-ki-mul) stem cells — another type of adult stem cell. These rare cells are derived from nonblood-forming cells in the bone marrow. Researchers managed to encourage a single mesenchymal stem cell to multiply into more than a million cells that could differentiate into fat, cartilage, bone and muscle cells.
In early clinical trials, mesenchymal stem cells appear to enhance standard bone marrow transplantation. Based on laboratory experiments, researchers hope that these stem cells may someday help treat diseases such as muscular dystrophy.
They also hope that injections of mesenchymal stem cells actually could grow replacement bone or tendon tissues lost to various injuries or diseases. Many hurdles remain, though, before these stem cells are fully understood.
The great unknown
Much remains to be learned about stem cells, including potential hazards. Real applications, for the most part, are still years away. But if progress with blood and bone marrow transplants is any indication, stem cell research will someday help many people.
National Institutes of Health: Stem cell information
© 2001 Mayo Foundation for Medical
Education and Research (MFMER).
Stem Cells Help Paralyzed Rats Move
By Will Dunham
WASHINGTON (Reuters) - Scientists said on Thursday they injected stem cells derived from an aborted human fetus into the brain of a laboratory monkey still in its mother's womb and found that they integrated nicely, pointing to the possibility of repairing brain abnormalities in human fetuses.
The study, led by Dr. Curt Freed of the University of Colorado School of Medicine in Denver and Dr. Evan Snyder of Harvard University Medical School and Children's Hospital in Boston, is the latest to highlight the potential offered by stem cells -- primitive master cells that can transform into other cell types -- for treating a variety of human diseases.
Freed said he foresaw the possibility of treating ailments such as Tay-Sachs disease, a fatal genetic disorder in children, by injecting neural stem cells into the brain of a developing fetus in the womb.
The study's publication in the journal Science comes as President Bush (news - web sites) mulls whether to allow federal funding for research involving a different type of stem cells -- embryonic stem cells generally derived from embryos left behind in fertility clinics after test-tube fertilization techniques.
The researchers used a clone of neural (nerve cell) stem cells derived from a human fetus that had been electively aborted about 15 weeks after conception. In the experiment, the scientists used fetal bonnet macaque monkeys that had developed for about three months inside their mother's womb at a laboratory at the University of Colorado.
The researchers took the human stem cells and directly injected them through the abdomen and uterus of the pregnant monkey and through the skull and into the fluid-filled space of the developing brain of the monkey fetus. They tracked the human stem cells as they joined the stem cell population lining the monkey's brain and entered the brain's developmental pathways.
PROMISE FOR TREATING HUMAN DISEASES
Freed noted that the human stem cells migrated through the developing monkey brain layers and became mature brain cells in the cerebral cortex.
"So what this means is that it may be possible to repair an abnormal human brain in utero and that it may be possible to replace or repair a metabolic defect that might lead to breakdown of the human brain after birth," Freed said in an interview.
He pointed to the possibility of treating human fetuses diagnosed with Tay-Sachs disease in the womb through injection of stem cells that, in theory, would fix the deficiency caused by the disease by generating healthy brain cells.
Tay-Sachs, resulting from the absence of a vital enzyme that damages nerve cells in the brain, causes progressive destruction of the central nervous system. The ailment is carried disproportionately by people of Eastern European Jewish descent.
The researchers found that the human stem cells segregated themselves into two separate populations during the fetal monkey's development. One population differentiated throughout the brain into nerve cells and glial cells, which support the neurons and account for about half of the brain's weight.
A second population remained undifferentiated and moved to a few regions in the brain, possibly providing a local pool of cells for self-repair and development, the study found.
Freed said he viewed the study as a "proof of principle" for treating a fetus in the womb with injected stem cells.
"There's a big step between proof of principle to actually making an impact on a specific kind of brain disorder in a developing human," he added. "That's what our article shows, that these neural stem cells can enter into the developmental pathway and produce normal brain cells, and so that's very encouraging."
Freed said the researchers were not assured of success.
"Another possible outcome could
have been that the cells that we put in could have formed a blob somewhere
in the brain lining and formed a mass of cells that could have caused problems
instead of being incorporated normally into the developing monkey brain,"
July 30, 2001
By David Baltimore. Mr. Baltimore, president of the California Institute of Technology, received a Nobel Prize in Medicine for his work on cancer.
Once in a long while, medical science comes up with a wholly new way to attack disease. A few years ago, such an opportunity presented itself with the discovery that human embryonic stem cells can be grown in large amounts. This provided science with a tool whereby new cells, tissues and organs could be grown that could replace diseased ones. No other technology offers such an opportunity. But nonetheless the Bush administration is considering banning federal funding of this very promising area of investigation.
Critics of stem-cell research allege that the embryos (which could come from either abortions or in vitro fertilizations) should be accorded all the protections available to a fully formed person. To me, a tiny mass of cells that has never been in a uterus is hardly a human being -- even if it has the potential to become human. By treating the use of such stem cells as akin to murder, we would lose a great deal.
Only embryos harbor cells with the potential to become every part of the human body. Such stem cells could be used to make up for the deficits in brain and pancreas cells that cause Parkinson's disease or diabetes. It is the only present hope that those who suffer from these ailments have. But curing their diseases will require a great deal more research -- research that a federal funding ban would disrupt.
Persuading stem cells to become tissues involves the work of many types of scientists. Some of these scientists need to be involved in learning to direct stem cells to adopt particular fates. This research involves using the use of inducing molecules, few of which are yet known. Once we know how to induce particular cell types, we will need to integrate them into various organs. If we can direct stem cells to form the insulin-producing cells of the pancreas, they could then be implanted directly because there is an existing organ structure in diabetic patients. The brain is a particularly important target because of Alzheimer's and Parkinson's diseases.
Stem-Cell Research: A Debate
By Robert P. George
But even if we can direct stem cells to form the different types of neurons lost in these diseases, we will still need to learn how to make them wire up correctly with the rest of the brain after they are transplanted. The regeneration of organs like the liver presents even more challenges because it would have to be built from scratch. This requires not only producing the multiple cell types that it contains, but also precisely organizing these cells into a three-dimensional tissue structure. Scientists in the developing field of tissue engineering are concerned with how to build such structures.
If the president bans federal funding of stem cell research, no building supported by federal funds could be used for such work. Thus, a scientist working in a university -- where indirect cost recovery permeates all structures -- could not simply get funds from a company or a private foundation, and do the work in his or her laboratory. The work would have to be done in space physically removed from other labs. But the need for integrating the highly specialized work of scientists with different skills suggests that the work will proceed most effectively in the existing buildings.
It has been suggested that adult tissues might provide an alternative source of stem cells. This is simply false. Adult tissues are not known to have cells with the potential to become all parts of the body. In adults, certain tissues (e.g., skin, blood and brain) do contain specialized types of stem cells, but they are not generic stem cells with the same properties as those derived from embryos.
Critics of embryonic research point to the remarkable capabilities of adult bone marrow stem cells. Not only can they reconstitute blood, but, a flurry of recent papers suggest, if transplanted into other organs, they may be able to generate neurons, muscle, liver and perhaps other cells, albeit inefficiently. It would be wonderful if these reports held up, but they are a long way from being definitive.
For adult stem cells to be a viable alternative to embryonic cells, at least three uncertainties would have to be resolved in their favor. First, when adult stem cells take on a new fate, they would have to provide the complete range of function. This has not been demonstrated. Second, the few types of adult cells that can be grown in laboratories would have to be able to make all of the many cell types in the body. No one has even claimed such an ability. Third, the process of changing fates, which is at best a very rare event, would have to be made efficient and controlled enough to regenerate whole organs. We are not close to achieving this. While research on adult stem cells should be pursued, we would be mad to trade their great uncertainty for the clear and exciting potential already evident in embryonic stem cells.
It has been suggested that, as a compromise, President Bush could allow work to go forward on existing cell lines but that federal support of work with new lines be banned. Unfortunately, we will probably need new lines because existing lines do not necessarily provide all of the capabilities needed for therapeutic stem-cell derivation. Also, more than 30% of all pregnancies spontaneously abort, making it hard to know if even the few existing lines come from nonaborted embryos. And to complicate matters further, the existing lines are largely tied up by commercial interests. This is a compromise that will anger many and satisfy few.
Embryonic stem cells hold remarkable promise for reversing the devastations of human disease. If the U.S. government does not fund this work, it will progress slowly in private laboratories and in foreign ones. The publicly funded American academic research effort is far and away the most effective research enterprise in the world. To refuse to allow it to participate in this exciting research would be an affront to the American people, especially those who suffer from diseases that could one day be reversed by these miraculous cells.
Copyright © 2001 Dow Jones &
July 28, 2001
Ross Mackenzie (back to story)
Whoever would have predicted even three months ago that stem-cell research would occupy the presidential mind and roil congressional heavy thinkers? But here it is, much like abortion (about which more later).
What can one say about it? A lot.
Stem cells are blastocysts, or cell clusters, that may be programmable to develop into various specific cells and tissues - and so to repair the afflicted. Science has a lot still to learn about the full extent of stem cells' beneficial use.
Researchers harvest stem cells from several sources - principally (1) from frozen petri-dish embryos no longer needed because the donors are on their way to parenthood; (2) from petri-dish embryos grown only for the cultivation of stem cells, and then destroyed; (3) from aborted fetuses; and apparently (4) from umbilical cords and other forms of adult tissue.
The debate goes generally to No. 2 above. A Virginia company is in precisely that business - essentially the same company that two decades ago gave the planet the first in-vitro, or test-tube, baby. A Massachusetts company, in the words of one news account, "is trying to use cloning technology to create human embryos that would yield [stem] cells, which in turn might give rise to tissues that were a perfect match for patients," thereby diminishing to near zero the rejection of implanted tissue.
Bioethicists are having a field day.
Says the University of Wisconsin's Alta Charo, "These two techniques involve embryos that would not have been lost. So they put, quite squarely, the question of how we balance our interest in protecting people who are already born and our interests in protecting embryonic life." The University of Chicago's Leon Kass notes adults may provide stem cells equally as promising as stem cells provided by embryos.
Both men suggest a central question in the developing stem-cell debate: What is the best, most prudent source of stem cells? (Indeed, a National Institutes of Health Report requested by President Bush, advises: "During the next several years, it will be important to compare embryonic stem cells and adult stem cells in terms of their ability to proliferate, differentiate, survive, and function after transplant, and avoid immune rejection.") Related questions arise the moment the mind begins to wander....
Is it ethically OK to draw stem cells from embryos created solely for research, as opposed to stem cells from leftover embryos or aborted fetuses? Are petri-dish embryos, created for whatever reason, human life? Conversely, is the destruction of petri-dish embryos the destruction of realized, inchoate, or potential human life? Is human cloning OK? (Ian Wilmot, the Scottish cloner of Dolly the sheep, offers an emphatic no.)
Should federal money fund research on stem cells drawn from petri-dish embryos? Does the 5-year-old congressional ban on federal funding of embryo research already apply to research on embryo cells? What about the 1993 law imposing ethical restrictions on fetal tissue research?
And, most crucially, when does life begin?
Which brings us to abortion.
Absolutists on one side say it begins at conception. The same people tend to say all research on embryos is wrong because petri-dish embryos constitute human life. Absolutists on the other side say life begins at birth. The same people tend to say all embryo and fetal research are fine because life does not begin until successful birth - as one would expect from individuals who support even partial-birth abortion, the killing of a fetus before it totally exits the birth canal.
Science could hugely help us answer lofty questions about abortion and stem-cell research if it would come to some agreement as to when life begins. At conception? At heartbeat? At brain wave? At quickening? At birth? The answer, whatever it is, would make issues like abortion and stem-cell research a piece of cake.
Until science provides that definitive answer - which it may never do - science and the nation, even the larger global community, must proceed cautiously.
Some clichés come to mind. One is federal money means federal control. That is largely true, and it means that in funding stem-cell research the federal government can greatly restrict it, for whatever good that will do. Yet who, including government, can stop science - or control it or restrict it?
Another is the truth, wherever it may lead. But the pursuit of scientific truth has led here and elsewhere to the atomic bomb and biochemical weapons. What if The Truth ultimately is that life begins at conception: Do we then continue with tossing petri-dish embryos into the trash? And of course, the Soviets' Pavlov and the Nazis' Mengele, and their epigoni, have done some of the most grisly things, and on government subsidy, the world has ever seen.
For good or ill, science will roll on. Whether it rolls in the proper (in this case, proper bioethical) direction will depend on our own ethical prescriptions and our own humaneness - and most prominently on the humaneness of the scientific community itself. .
©2001 Tribune Media Services
JUL 28, 2001
By THE ASSOCIATED PRESS
WASHINGTON, July 28 — More than 200 members of Congress, including 40 Republicans, have sent a letter to President Bush urging him to support federal funding of embryonic stem cell research with strict oversight.
"You have the lives of millions of our — and your — constituents in your hands," the lawmakers wrote.
Circulated by Representatives Jim Ramstad, Republican of Minnesota, and Diana DeGette, Democrat of Colorado, the letter cites reports that a private laboratory has created human embryos for stem cell research as evidence that federal oversight is needed.
"The only way to ensure that embryonic stem cell research is conducted with strict ethical and legal guidelines is to provide federal funding and oversight," the letter states.
The lawmakers also note the potential to find cures for diseases.
Last week, 59 senators sent Mr. Bush a letter supporting the research. More than a dozen Republican senators are on record urging him to support the research, including Bill Frist of Tennessee, a doctor, who opposes abortion.
Copyright 2001 The New York Times
By Anne E. Kornblut, Globe Staff, 7/29/2001
WASHINGTON - Hardly anyone noticed when George W. Bush said last year that he believed human life begins at conception. Bush was only restating a fundamental tenet of the antiabortion movement.
But as the debate over stem cell research has grown into a sweeping moral battle, politicians and the nation as a whole have been forced to take a harder look at theories about the moment life begins. Even the notion of "a moment" of conception is itself now up in the air, vastly complicating matters for President Bush as he weighs whether the government should fund research.
Many of the researchers who are eager to work with the cells drawn from 1-week-old embryos cite a longstanding position that an embryo becomes an individual human when it can no longer divide into twins - usually at about two weeks. Others argue that life begins around 26 hours after the sperm penetrates the egg, when the chromosomes of both meet.
One prominent scholar has just published a book arguing that there is no exact time when life begins.
Religion is no more uniform: While the Roman Catholic and Southern Baptist churches hold that life begins at conception, many Reform and Conservative Jews, as well as many Muslims, believe that individuals are formed after the first 40 days.
The split between religion and science, and within the religious community itself, presents a political dilemma for Bush, who has delayed the decision on stem cell research funding far longer than expected.
But the fundamental debate over when life begins - a critical piece in determining whether to move forward with stem cell research, which must destroy embryos in order to extract the stem cells - also offers a window into the complexities that government faces in a new era of cellular research, as legislators consider whether to push the United States to the outer edges of science.
"This is one of the most striking encounters between the research community and government going back 25 years," said Ronald M. Green, director of the Ethics Institute and chairman of the religion department at Dartmouth College. Green recently wrote "The Human Embryo Research Debates," a book on the controversy.
"It's forcing us to reconsider our ethics," he said. "It's very healthy, in my view. Science does change ethics. Our principles don't change, our values don't change, but the facts we work with change. So this is a very healthy encounter between developing science and some of the pat assumptions that have prevailed in people's minds."
Senator Bill Frist, a Tennessee Republican who favors limited stem cell research, was more pessimistic. "I believe we are ill-equipped today in the United States Congress to deal with this issue. We do not have the larger moral and ethical framework," he said.
One common assumption, fueled largely by the modern debate over abortion, is that Catholics have always believed life begins at the moment of conception. In fact, the Catholic Church did not settle on that view until 1869, when, after scientific advances, Pope Pius IX removed the previous distinction between an "unensouled" and an "ensouled" fetus - declaring that God infuses each individual with a soul immediately after conception instead of weeks into the pregnancy, a distinction that had been held for nearly three centuries.
Over time, opinion about the beginnings of life has adjusted according to scientific discovery. Aristotle held that the fetus started out as a kind of vegetable, becoming a person after 40 days (or 90 days, in the case of women, whom he considered mutant males). After the microscope was invented, scientists got a close-up look at sperm and decided it must be responsible for generating all of human life. That view changed after the discovery of the egg, and soon scientists saw that the joint product could split in half.
This twinning capability, which ends around 14 days after fertilization, became a landmark for many scientists. At two weeks, the embryo begins to develop a "primitive streak" - a mark that suggests the formation of a backbone, and indicates that cells are beginning to differentiate to form organs.
According to Robert Lanza, medical director of Advanced Cell Technologies in Worcester, where human embryo cloning research is being performed, "That is the first time it can be called a person."
Opponents view the two-week marker as arbitrary - and a little too convenient, given how nicely it dovetails with the needs of would-be stem cell researchers.
"You've got human life at whatever stage of development. That's indisputable," said Carol Taylor, director of the Center for Clinical Bioethics at Georgetown University Medical Center. "At that point until natural death you have an entity that commands respect."
In parts of Australia, where stem cell research is banned, the government has defined life as beginning at "syngamy" - the point about 26 hours after the sperm penetrates the egg when their chromosomes combine. Yet that, too, seems arbitrary to some specialists. Green, who supports stem cell research, argues that life is a continuous process, starting with the individual egg and sperm.
"When do you die? We used to think there was this decisive moment. Then we found we could separate the life of the brain from the rest of the body," he said. "I don't think there is a moment [life begins]. I don't think that nature and science are going to give us a moment. I think that all they are going to present us with are decisions. The proper question is, when must we, as a moral community, decide to protect nascent human life?"
President Bush has yet to explore such weighty questions in public, keeping his counsel as he tries to decide how to proceed. But Frist, a former transplant surgeon, has developed a compromise between his faith in science and his strict opposition to abortion.
Frist maintains that life begins at the earliest point of conception. But he also supports research on stem cells derived from excess frozen embryos created for fertilization, arguing that, like transplants, it is ethical to make good use of living tissue that would otherwise go to waste.
Unlike Senator Orrin Hatch, an antiabortion Republican who supports stem cell research and argues that embryos are not living beings outside the mother's womb, Frist believes that destroying an embryo for research is technically "destroying a life, just like I take out that heart, that liver" from a dying patient for a transplant.
"There are some people who will say, 'If that's life, you should give equal moral consideration to these cells as you do to a human being,"' Frist said last week. But, he argued, "You don't have to be absolute and say, 'Is that a human being?' That's an oversimplification. ... That doesn't capture what I believe are all the ethical considerations."
Anne E. Kornblut can be reached via
e-mail at email@example.com
This story ran on page A1 of the Boston Globe on 7/29/2001.
© Copyright 2001 Globe Newspaper Company
Published Thursday, July 26, 2001
Those who oppose cloning research are guilty of negligent homicide.
That, at least, is the inescapable conclusion you must reach if you take seriously the arguments of those who oppose research into both cloning and embryonic stemcells.
Those who oppose the use of embryonic stemcells describe the destruction of any embryo, once formed, as murder because it ends a potential life. But cloning, once perfected, turns every single cell in a human body into a potential life. If ending a potential life constitutes murder, then preventing actions that allow those lives to happen must constitute negligent homicide.
Q.E.D., as we used to say in geometry class.
This argument is bunk, of course, but the reason it's bunk reveals most objections to the use of embryos conceived in vitro for stemcell research to be misguided. The reason is that describing a human blastomere -- the earliest stage of embryonic development -- as a human being requires a definition of humanity we should reject.
The ethical issues surrounding embryonic stemcell research are often framed around the question of when life begins. This is the wrong question, and as with most wrong questions, even the right answer is misleading. The question we should be asking ourselves is what makes something a human being. This question is easily asked but not easily answered.
The blastomere-as-human definition requires us to consider anything that has the DNA of Homo sapiens to be human. But DNA is simply a blueprint, or maybe an instruction manual, used by the fertilized ovum to direct its development from single cell to baby, by the baby to develop into a child, then teenager, then adult, and by all stages for ongoing metabolism. If destroying a blastomere is murder, then burning a set of blueprints must be arson -- but it isn't, of course. Destroying instructions may be a crime in some situations, but it isn't the same crime as destroying the thing the instructions help you build and operate.
What does it mean to be human? We each have our own definition, and the history of philosophical inquiry suggests we won't reach a consensus on the subject anytime soon. My own definition is that the critical properties of humanity are reasoning, communication and self-awareness, and I'm quite willing to grant the title human to anything that is able to reason and communicate, and is aware of itself.
Many people are uncomfortable with this definition. Certainly, it can be quite inconvenient. Chimpanzees, for example, easily pass the test, and pass it better than a blastomere, a first or second-trimester human embryo, and even some past colleagues whose ability to qualify was questionable enough that I tried to keep them out of staff meetings.
Stemcell research holds tremendous potential for saving and improving the lives of human beings who have already been born and are now alive. The opponents of this research tell us it's immoral, because it involves killing potential human beings.
Here's another morality: Preventing the use of un-self-aware, unreasoning cells that share our DNA to save the lives of self-aware, reasoning, communicating human beings is as unconscionable as withholding CPR from a heart-attack victim.
Once you accept the reason/communication/self-awareness definition of humanity, have we resolved all of the difficult ethical issues? Of course not. Philosophers, who ponder ethics for a living, haven't yet resolved even the most basic of ethical issues to everyone's satisfaction. Waiting to act until we've formulated an incontrovertible analysis of every scenario we can imagine occurring in some distant future condemns to suffering and death countless human lives we can save tomorrow if we choose to.
To many of us, there's no more immoral choice we can make.
-- Bob Lewis, of Maple Grove, is a consultant.
© Copyright 2001 Star Tribune
Friday, July 27, 2001; Page A31
By Charles Krauthammer
Hadn't we all agreed -- we supporters of stem cell research -- that it was morally okay to destroy a tiny human embryo for its possibly curative stem cells because these embryos from fertility clinics were going to be discarded anyway? Hadn't we also agreed that human embryos should not be created solely for the purpose of being dismembered and then destroyed for the benefit of others?
Indeed, when Sen. Bill Frist made that brilliant presentation on the floor of the Senate supporting stem cell research, he included among his conditions a total ban on creating human embryos just to be stem cell farms. Why, then, are so many stem cell supporters in Congress lining up behind a supposedly "anti-cloning bill" that would, in fact, legalize the creation of cloned human embryos solely for purposes of research and destruction?
Sound surreal? It is.
There are two bills in Congress regarding cloning. The Weldon bill bans the creation of cloned human embryos for any purpose, whether for growing them into cloned human children or for using them for research or for their parts and then destroying them.
The competing Greenwood "Cloning Prohibition Act of 2001" prohibits only the creation of a cloned child. It protects and indeed codifies the creation of cloned human embryos for industrial and research purposes.
Under Greenwood, points out the distinguished bioethicist Leon Kass, "embryo production is explicitly licensed and treated like drug manufacture." It becomes an industry, complete with industrial secrecy protections. Greenwood, he says correctly, should really be called the "Human Embryo Cloning Registration and Industry Facilitation and Protection Act of 2001."
Greenwood is a nightmare and an abomination. First of all, once the industry of cloning human embryos has begun and thousands are being created, grown, bought and sold, who is going to prevent them from being implanted in a woman and developed into a cloned child?
Even more perversely, when that inevitably occurs, what is the federal government going to do: Force that woman to abort the clone?
Greenwood sanctions, licenses and protects the launching of the most ghoulish and dangerous enterprise in modern scientific history: the creation of nascent cloned human life for the sole purpose of its exploitation and destruction.
What does one say to stem cell opponents? They warned about the slippery slope. They said: Once you start using discarded embryos, the next step is creating embryos for their parts. Frist and I and others have argued: No, we can draw the line.
Why should anyone believe us? Even before the president has decided on federal support for stem cell research, we find stem cell supporters and their biotech industry allies trying to pass a bill that would cross that line -- not in some slippery-slope future, but right now.
Apologists for Greenwood will say: Science will march on anyway. Human cloning will be performed. Might as well give in and just regulate it, because a full ban will fail in any event.
Wrong. Very wrong. Why? Simple: You're a brilliant young scientist graduating from medical school. You have a glowing future in biotechnology, where peer recognition, publications, honors, financial rewards, maybe even a Nobel Prize await you. Where are you going to spend your life? Working on an outlawed procedure? If cloning is outlawed, will you devote yourself to research that cannot see the light of day, that will leave you ostracized and working in shadow, that will render you liable to arrest, prosecution and disgrace?
True, some will make that choice. Every generation has its Kevorkian. But they will be very small in number. And like Kevorkian, they will not be very bright.
The movies have it wrong. The mad scientist is no genius. Dr. Frankensteins invariably produce lousy science. What is Kevorkian's great contribution to science? A suicide machine that your average Hitler Youth could have turned out as a summer camp project.
Of course you cannot stop cloning completely. But make it illegal and you will have robbed it of its most important resource: great young minds. If we act now by passing Weldon, we can retard this monstrosity by decades. Enough time to regain our moral equilibrium -- and the recognition that the human embryo, cloned or not, is not to be created for the sole purpose of being poked and prodded, strip-mined for parts and then destroyed.
If Weldon is stopped, the game is up. If Congress cannot pass the Weldon ban on cloning, then stem cell research itself must not be supported either -- because then all the vaunted promises about not permitting the creation of human embryos solely for their exploitation and destruction will have been shown in advance to be a fraud.
© 2001 The Washington Post Company
By Ellen Goodman, 7/8/2001
I SUPPOSE THAT those of us who have been in this struggle a while can be forgiven for taking a little pleasure at the civil war erupting among our opponents. Suddenly, politicians who call themselves "prolife" are fighting over who deserves to wear that uniform.
Orrin Hatch, an antiabortion stalwart, is now saying defensively that "people who are prolife are also prolife for existing life." Our point exactly. Isn't this why prochoice folks resent the coopting of the term "prolife"?
But smugness won't do. We are witnessing what happens to every thoughtful person who wades into the moral terrain of reproductive technology.
This time the firm line drawn by the prolife forces - life begins at conception - begins to soften. The simple battle cry - a fertilized egg is a human being - begins to develop a counterpoint. The solid ground under the absolutists is beginning to shake.
This civil strife is over embryonic stem cells. These cells, harvested from five-day-old fertilized eggs, may offer the best hope - better than adult stem cells - for curing some pretty awful diseases, from Alzheimer's to Parkinson's to juvenile diabetes. So the Bush administration must decide whether the government will fund research that uses stem cells from fertility clinic embryos.
The argument over using the "leftovers" of couples who have given such permission has divided old antiabortion allies. On the one hand, senators like Strom Thurmond and Connie Mack and Gordon Smith have come to agree with Hatch that stem cell research is "the most prolife position" because of the possibility of saving lives. On the other hand, Republican House leaders like Dick Armey and Tom DeLay and J.C. Watts warned Bush: "It's not prolife to rely on an industry of death even if the intention is to find cures for diseases."
The president, stalling for time, searching for an elusive compromise, has said he will decide "in a while." But which will it be? Using the stem cells for potentially life-saving research? Or letting the embryos remain in some fertility clinic locker to be frozen or destroyed?
To condemn stem cell research as an "industry of death," you must begin by opposing in-vitro fertilization. The Catholic Church, consistent if nothing else, opposes the creation as well as the destruction of a fertilized egg outside of the womb.
But most Americans regard in-vitro fertilization - IVF - as a blessing for many couples and see fertility clinics as places where life begins. So, as bioethicist Bonnie Steinbock says, the political wrangling must leave these people scratching their heads.
"You mean," she says, imagining their conversations, "creating surplus embryos is fine, discarding embryos is fine, keeping them in the freezer in perpetuity is fine, the only thing that is not fine is using them for medical research?"
Steinbock, a professor of philosophy at the University at Albany, part of the State University of New York, says many who are normally prolife cannot reconcile discarding or freezing eggs as more respectful of life than using them to find a cure. Those who may not identify with a desperately pregnant woman in search of an abortion find themselves siding with a desperately sick person in search of a cure.
In some ways, the endless abortion argument has driven all other discussion over reproduction to the extremes. At one end, the fertilized egg is talked about as little more than tissue. On the other end, it is given the full moral stature of a human being.
Those who favor abortion rights have been challenged by the grim choices of late-term abortions. Until now, though, as Thomas Murray of the Hastings Center says, "The prolife movement has been able to dodge a problem within their ranks for many years: the moral status of the very early embryo, prior to implantation, perhaps not even within a woman's body."
Now, in this civil war over "life," they face a parallel divide. "Most people," says Murray, "do not view either birth control as murder or IVF then freezing as equivalent to placing your 5-year-old in the deep freeze."
If there is one thing that comes out of this political skirmish, it's the understanding that an embryo created in a dish is not a thing and not a person. We cannot use embryos for frivolous purposes. "We don't make earrings out of them, we don't use them in high school labs," says Steinbock. But we can, with seriousness and respect, use them for medical research that will, one hopes, save lives.
Yes, being "prolife" also means being "prolife for existing life." Those who now call themselves prolife and pro-stem cell research have had to give up the simple and simplistic idea that a fertilized egg is a full and equal human life. Welcome. There's plenty of room under the banner that reads: It's more complicated that that.
Ellen Goodman's e-mail address is
This story ran on page 7 of the Boston Globe on 7/8/2001.
© Copyright 2001 Globe Newspaper Company
28th July, 2001
BY BOB REEVES Lincoln Journal Star
The key issue in the ethics of embryonic
stem cell research is the question of whether an embryo is - or isn't -
a person, said Sister Renee Mirkes, a medical ethicist who has written
extensively about the issue.
Mirkes, director of the Center for NaProEthics at the Pope Paul VI Institute in Omaha, said Friday she believes an embryo clearly is a person and should not be destroyed for any reason - even to help cure diseases such as Alzheimer's, Parkinson's or multiple sclerosis.
She spoke in Lincoln to 85 people from across the country attending the 20th annual meeting of the American Academy of Natural Family Planning.
Mirkes is encouraged by recent research suggesting adult stem cells could be used in the same ways as embryonic stem cells to repair damaged or deteriorated nerves and other tissues, she said. The most promising development is identifying "master stem cells" in adults that could be cultured to grow almost any organ or tissue.
"This is absolutely good news," she said. "I honestly think (President) Bush yet might come down hard (in support of ) adult stem cell research" and ban federal funding for embryonic research.
Many researchers argue that destroying human embryos to extract stem cells is justified because embryos don't function like people and, therefore, lack the same rights. For instance, embryos are not self-conscious, don't think, communicate or make decisions.
But Mirkes noted that those in comas or anesthetized -- even those who are asleep -- don't exhibit characteristics often associated with persons. No one would argue an anesthetized adult is not a person, she said.
Some scientists deny embryos are people because they "fail to elicit feelings of fellowship when we look at them in a petri dish or under the microscope," she said. "Would we be rid of slavery or the systematic annihilation of Jews today if we were to persist in awarding or denying personhood . . . on the basis of sight and feeling?"
Asked by a reporter to respond to Mirkes' comments, Dr. Sam Cohen, a University of Nebraska Medical Center pathology and microbiology professor, said he believes alternatives to embryonic and fetal stem cells should be used whenever possible. But he added: "At the present time, it does not appear that adult stem cells can do everything that embryonic stem cells can do, nor can we get enough of them."
He also noted adult stem cells may not survive long enough in the laboratory to be usable for research.
The federal government should put more money into adult stem cell research, Cohen said, but it should also continue funding embryonic and fetal cell research.
The conference began Wednesday and continues through 10 p.m. today at the Villager Convention Center. The organization represents natural family planning practitioners and medical consultants who promote family planning without the use of artificial birth control.
Reach Bob Reeves at firstname.lastname@example.org
Copyright © 2001, Lincoln Journal Star
Saturday, July 21, 2001
By Alan Keyes
Much attention is focused right now on President Bush's preoccupation with the question of what, if any, restrictions should be placed on the harvesting of medically-promising "stem cells" from artificially conceived human embryos. The choice is usually described as "complex" or as a "dilemma," and we are told that it involves new and unfamiliar factors. I would like to suggest that it is, instead, a fairly simply matter, raising the oldest moral question: Will we do what is right, or merely what seems useful?
This was the question, posed in the form of slavery, that hung over the early Republic so darkly that the survival of American self-government itself was eventually cast into deep and bloody doubt. Despite efforts to present slavery as an institution motivated chiefly by racism and prejudice, the truth is that the foundation of slavery was greed and the consequent willingness to disregard the dignity of human beings for the sake of profit and material comfort.
Laboratory techniques such as cloning and embryonic manipulation are now confronting us with the same temptation - that we may disregard the dignity of some human beings for utilitarian "benefit." This arbitrary discrimination is proposed to rest upon how these tiny human beings are conceived. Those conceived after the fashion of the bedroom are entitled to rights equal to ours, it seems (unless their mothers object before birth, but that's another story) . But we are being asked to presumptively disrespect the humanity of those who are conceived in a petri dish, so that society may put them to use for its own purposes.
Our leaders, we are told, are "agonizing" and "wrestling with their conscience" on this issue, because of the difficulty of balancing the alleviation of human suffering through medical advances with the moral cost of "harvesting" embryos. We should be clear that the "dilemma" presented by the "opportunity" to begin a morally illicit exploitation of a class of innocent human beings is essentially no different than the decision to introduce the commercial slave trade into the New World. Do we really want to veer off the Founders' path of striving to uphold the cause of human equality? For the sake of a momentary acceleration of the pace of medical magic, we risk a permanent detour onto the corrupting path of justifying evils first as necessary, and later as "positive goods."
Gentlemen of the southern slave owning states willfully decided that, despite their professed paternal affection for their slaves, it was necessary to sacrifice the black man's humanity for the sake of the white man's bread. It was a decision that corrupted the slave owners themselves, requiring increasingly tortured rationalizations in the search for a peace that could not be found in economic gain or clever theories of the "positive good" of slavery itself.
We stand on the brink of a similar self-destruction. Violating the dignity of other human beings for the sake of benefits to our own health and comfort is simply to choose greed over justice, whether the profit to us is the cash crop of cotton or high-tech medicine. If we make the wrong choice, we will ensnare ourselves in the same web of self-justification and nagging doubt that hardened the conscience of the pre-war South. And the tragedy will be that we did so simply because we were in a hurry to achieve material advantages that will be decently accomplished soon enough anyway.
Once we have adopted the position that anonymous embryos can be denied equal respect because of the circumstance of their origin, the principle at the root of the decision will be inexorably advanced. Human ingenuity will soon devise ways to bring fully developed human beings forth without the benefit of the normal process of procreation. That's what cloning represents for us now - not science fiction anymore, or a distant and hypothetical future, but a fundamental moral issue that we must confront in principle now. The seeds that we plant in our thinking today will decide whether or not, in the course of this century, we shall see whole new classes of human beings brought into existence by our cleverness but condemned to indignity, injustice, exploitation and slavery just as my ancestors were condemned.
I can think of a fate worse than being born into a generation that accepted slavery. It is to be born into the generation that renewed the horrors of slavery for millions yet unborn. And if we are not careful, that will be our fate.
We can avoid it by seeing in the current debate an opportunity to renew our allegiance to the great principles of our Declaration of Independence. The Declaration not only proclaims our rights, it implies a necessary discipline in our use of those rights. Our right to the pursuit of happiness depends upon our willingness to acknowledge the limits and checks on human power and human willfulness. Our rights depend upon submitting our human will to the authority of a transcendent and benevolent power that wisely dictates that we respect the life and dignity of every human being, regardless of station, of strength, of condition or of the circumstances of birth.
If we understood this, we wouldn't even think of trading our extraordinary national heritage of liberating moral dignity for the pottage of a few years advancement in the development of new medicines. We would recoil in horror from the suggestion that we consider violating the dignity of human offspring for the sake of marginal improvements in our material condition.
The decades to come will see an avalanche of "liberating" technological developments, as man's ability in practical terms to alleviate suffering and enhance the material conditions of human life, particularly for the poor, achieves critical mass. But will these technologies be placed in the service of human dignity, or will human dignity be sacrificed to the technology - and to those powerful enough to control it?
For the beneficiaries of science, the result will appear much the same - health and comfort will increase, at a material cost that diminishes toward invisibility. The question we must face is whether those beneficiaries will sit, as the plantation owners of old, on shady porches of leisure while their hired agents extract what they want from whomever they need to use - and abuse.
The American choice - and the right
choice - is to ask first if we are doing our duty to those God has willed
that we acknowledge as our equals in dignity, and our brothers in the pursuit
of happiness. This is the question that the embryonic stem-cell debate
is really about, and it is, as well, the question of the future of American
Our position: The president should reject federal funding of stem cell research that destroys human life.
July 27, 2001
Though pressured to do so, President Bush refuses to be rushed into deciding the grave issue of federal funding for embryonic stem cell research. He made his opposition known before his election and since, but whether he will lift the current ban remains a matter of speculation.
We urge him to hew to his position that it is morally wrong to destroy life, which is what occurs when stem cells are extracted from human embryos. A growing body of scientific thinking believes it is also unnecessary.
Celebrity appearances before congressional committees and much media coverage have created the false perception that stem cell research has come to a dead stop. And without the resumption of federal funding, hope for medical breakthroughs will be dashed and promised miracles never realized. That is far from fact.
Intensive research into stem cell potential proceeds at a fast clip in major biotech laboratories around the world and has been doing so for several years. Results have been reported in well-known scientific and medical publications. Realizing the payoff at stake, the private sector lavishly funds research on both stem cells drawn from live embryos and adult volunteers. Therefore science doesn't need federal subsidization. So says Richard Miniter in a lengthy article in the European edition of the Wall Street Journal.
The private sector is putting its money heavily on adult stem cells. Of the 15 U.S. biotech companies solely devoted to developing cures using stem cells, only two focus on embryos. Research in adult cells is advanced. By contrast, research in embryonic cells is in the preliminary stages. It is lack of promising research to finance, not lack of funds, that is responsible for the lag, says Miniter. He calls the National Institutes of Health's report favoring embryonic cells "shaky and speculative." It's an opinion shared by others.
"While embryonic cells are said to have broad potential, so far only adult stem cells have demonstrated wide uses," says Scott Gottlieb, a physician and writer for the British Medical Journal. John Wong, CEO of MorphoGen Pharmaceuticals agrees. "The technology has moved beyond stem cells from embryonic tissue," he said.
A major reason is the discovery that adult stem cells are more numerous and versatile than originally assumed. Confirmation has been reported by such respected sources as Dr. Ira Black of the Robert Wood Johnson Medical School; Dr. Jeffrey Leiden, formerly of Harvard and now chief scientific officer for Abbott Laboratories; and biologist Fred Gage of the Salk Institute.
New findings in the area of stem cell research are reported in scientific journals almost every week. More often than not, the details are mind-boggling to non-professionals. But the key to the stem cell quandary was stated simply and succinctly by Sen. Sam Brownback, R-Kan. If we harvest adult tissue, he told Senate colleagues, "We don't have to kill anybody."
We hope President Bush was listening.
Why killing embryonic human beings is wrong.
By Patrick Lee & Robert P. George.
Mr. Lee is associate professor of philosophy at the Franciscan University
of Steubenville. Mr. George is the McCormick Professor of Jurisprudence
at Princeton University
July 20, 2001 11:40 a.m.
At the heart of the debate over federal funding of embryonic-stem-cell research is the question whether human embryos are human beings. Perhaps the most plausible argument that they are not takes the form of a reductio ad absurdum. Ronald Bailey, science editor of Reason magazine, argues that the possibility of cloning human beings from ordinary somatic cells, such as the skin cells millions of which each of us rubs or washes off our bodies on any given day, means that human embryos are no different in substance and value from such cells. But nobody maintains that skin cells are human beings; therefore it is an error, Bailey concludes, to suppose that embryos are human beings. We need be no more concerned about destroying embryos than we are about shedding skin cells.
Bailey's article is entitled "Are Stem Cells Babies?" The title itself is fallacious. No one claims that stem cells are human beings (or "babies"). Rather, human embryos, from whom stem cells are sometimes obtained, are living, albeit very young, human beings. What has been proposed is the obtaining of stem cells by dissecting these living human beings. We object, not to the use of stem cells as such (which can be obtained elsewhere, without killing), but to the dismemberment of live human beings as a means to obtain them.
Bailey argues that each of our own cells has as much potential for development as any human embryo. He notes that cloning has shown that each of our cells has the genetic information necessary for producing an entire human embryo, when joined to an enucleated (nucleus removed) ovum and placed in the right environment. Each cell (Bailey notes) has the entire DNA code; it has become specialized (as muscle, skin, etc.) by most of that code being turned off. In cloning, those portions of the code previously de-activated are re-activated. Bailey quotes Australian bioethicist Julian Savulescu: "If all our cells could be persons, then we cannot appeal to the fact that an embryo could be a person to justify the special treatment we give it."
Bailey's argument fails because his proposed analogy between somatic cells and human embryos is false. The analogy is false for two reasons. First, the kind of potentiality possessed by each of our cells differs profoundly from the potentiality of the human embryo. In the case of somatic cells, each has a potential only in the sense that something can be done to it so that its constituents (its DNA molecules) enter into a distinct whole human organism (which is a person). In the case of the human embryo, he or she already has the potential to actively develop himself or herself to the further stages of maturity of the same kind of organism he or she already is.
True, the whole genetic code is present in each somatic cell, and this code can be used for guidance of the growth of a new entire organism. But this point does nothing to show that its potentiality is the same as that of a human embryo. In cloning, the nucleus of an ovum is removed and a somatic cell is placed in the remainder of the ovum and given an electrical stimulus. Such acts do much more than bring out the latent potentialities of a cell, or merely place a cell in a new environment. The somatic cell is unable to produce a new embryo by itself, but must work together with an enucleated ovum; unlike a new embryo, it needs more than just the right environment to develop to a mature stage of a human being.
A change in environment is merely external. But the result of cloning is an entirely new organism: There is an internal change in the kind of thing present. The evidence for this is the entirely new direction of its activities and reactions. Thus, the relevant potentiality of somatic cells is merely that their genetic materials can be used, in conjunction with an enucleated ovum, to generate an embryonic human being. But the potentiality of the human embryo, like that of the human infant, is precisely the potentiality to mature as the kind of being it already is — a human being. Somatic cells, in the context of cloning, are analogous, not to embryos, but to gametes (sperm and egg). Just as a person who comes into being as a result of the union of gametes was never a sperm or an egg, a person who is brought into being by a process of cloning was never a somatic cell. But you and I truly were once embryos, just as we were once fetuses, infants, and adolescents. These are merely stages in the development of the enduring organism — the human being — we are.
Bailey may be running into some confusion because the fact that a human embryo has a complete human genetic code in each of his or her cells is part of the proof that he or she is a distinct human being. But it is only part: the other evidence is that its genetic code is distinct from that of the mother, it is growing and developing by virtue its own direction, the direction of this growth is the mature stage of a human being, and so on. In other words, having the entire human genetic code shows that an entity is human, but other facts show that the human embryo is distinct (distinct from any cell of its mother or father). And still other facts show that it is whole (not functionally a part of a larger organism), a self-integrating member of the human species.
The second reason why Bailey's analogy is false is that it ignores the most obvious difference between any of our cells and a living human embryo, a difference that is crucial for discerning how they should be treated. Each of our cells is a mere part of a larger organism; but the embryo is himself or herself a complete, though immature, organism. Somatic cells are not, and embryonic human beings are, distinct, self-integrating organisms capable of directing their own maturation as members of the human species.
In fact, Bailey's argument from the possibility of cloning amounts to a red herring. Cloning shows only that human beings can be produced asexually, something we already knew with identical twins (the second twin comes to be with the splitting of the original embryo, which occurs in about 1 in 270 live births).
Scientists, science writers, philosophers, and others involved in the debate over embryonic-stem-cell harvesting hold various views of the ethics of embryo destruction. The facts of science, however, are clear: Human embryos are not mere clumps of cells, but are living, distinct human organisms, the same as you and I were at earlier stages of our lives. With the fusion of sperm and ovum, or with the coming to be of a distinct and complete (though immature) human organism either by (identical) twinning or by cloning, there is present a distinct organism which will (unless prevented) actively develop himself or herself to a more mature stage as a member of the human species. This new organism directs its own growth, coordinating from within all of its elements and forces toward his or her own survival and maturation.
It will not do to say that these are human beings but not "persons." You and I are essentially human, physical organisms. That is, we do not have organisms; we are rational, animal organisms. Therefore, we — that is, the persons we are — come to be precisely when the animal-organisms we are come to be. The human person is a bodily entity — not a mere consciousness using a body — and so the human person comes to be at conception.
Nor will it do to say that the individual that you are did come to be at conception but that you became valuable, or deserving of respect, only much later in your duration. You yourself and I myself are intrinsically valuable, not mere carriers or vehicles for what is intrinsically valuable (such as pleasant or interesting experiences). For, if we were mere carriers or vehicles of what is intrinsically valuable, it always would be permissible to kill one child provided people agreed to replace him or her with two others. But that is ludicrous. Therefore, persons, at whatever age or condition, are valuable simply by virtue of being persons, that is, things that have the basic capacity to shape their own lives, even if it may take them some time to develop that capacity, or even if some defect blocks the actualization of that capacity. All persons, of whatever race, sex, nationality, or age, are deserving of full respect, and none should be treated as mere means for use — for example, dissected for their body parts — by stronger persons.
Finally, the pro-life position is widely reported (even by some not hostile to it) as being opposed to stem-cell research because human embryos "are life." This is inaccurate. They are not just "life," or even human life, but distinct, individual, living members of the human species, just as you and I were at an earlier stage of our lives. The proposal to dissect these individuals for their spare parts — and to implicate all of us in this injustice by publicly funding and promoting it — is grotesquely immoral.
Get rid of mind-body dualism and recognize embryos as human beings
July 27, 2001
BY JOSE A. BUFILL
The debate raging over the use of human embryos and their stem cells is important for many reasons. Perhaps the least important of these relates to the physical ailments that might, in the future, be cured using these techniques. The debate is more important because it is part of a broader conflict whose origins can be traced back for centuries: a clash determined by vastly different ways of understanding what it means to be human.
About 400 years ago, a genius named Rene Descartes -- a man who contributed important and durable insights to science -- goofed when he dabbled in philosophy. He succeeded in driving a deep wedge between the once well-integrated spiritual and physical dimensions of the human person. Over time and almost imperceptibly, the "split" that Descartes imagined between the mind and the body took root, first among intellectuals. Today, it is flourishing in attitudes and behavior at all levels of society.
Thanks to Descartes, Deepak Chopra can claim, "Your body is just the place your memories call home," and people will buy his books. There are many other examples in popular culture that express the theoretical mind-body split in practical ways. But perhaps none is as disturbing as the prevailing attitude of science and society toward human embryos.
Scientists have become exceptionally skilled at growing them up in a petri dish. They can tell us what they might look like if they are allowed to develop and how they might suffer and die from diseases inscribed in their genes. They tell us the great good that someday may come from using parts of them to treat the diseases of other people. They may feel quite satisfied when they discard some embryos in favor of others. They are simply selecting those less likely to burden society and more likely produce. They are strengthening the gene pool and giving another human the best chance for a "good life." But they refuse to grant the human embryos they use the most vital gift of all: respect.
And the reason scientists are incapable of respecting the humanity of their embryos is because "your body is just the place your memories call home." They view the particular human body they are working on as a shell, a car in need of a driver. It can be produced, discarded or recalled for factory defect. It has no memory, no past and, if they decide so, no future.
It's clear that Descartes had no idea what he was getting into when he split himself and us in two. But ideas do have consequences, and unfortunately, bad ideas may have very bad consequences. After four centuries of mind-body dualism, it is time to put things back in their proper place. Honest science must accept nature on its own terms. Bias defeats its purpose, and it is the voice of antihuman bias in science today that claims that an organism shown to be genetically human, biologically human and anatomically human is just a body and not a human.
To be human is to be both body and spirit. Each completes the other, and together both confer wholeness and integrity to each and every human person.
To arbitrarily deny the full humanity of a human embryo is symptomatic of the disintegration that some human beings have forced on others. Today, the weak, the dying, the disabled and those who are unable to speak for themselves, can easily be defined, either in theory or in practice, as less than human. They become living, breathing shells devoid of spirit, of value and therefore of humanity.
Some today might ask, not without an edge of cynicism, "So when exactly does the embryo become a human being?" This critical question is one that science is now fully equipped to answer unambiguously: "It has always been a human being." Where there is a physically distinct human organism, alive and growing, there is a complete human organism. From the moment of conception, there exists an autonomous human life. All that he or she needs to develop is proper nourishment. Nothing else needs to be added to them.
The ethical dilemmas posed by stem cell research, pre-implantation genetic testing and other assisted reproductive technologies are caused by the dualist view of the human person that has dominated scientific theory and practice for four centuries. This view turns the embryonic human body into the disposable part of a potential person, rather than an integral part of a whole person. We should recognize that treating the human body in this way has implications far beyond science and academia.
Could it be that the many real and imagined conflicts that polarize families and society today are an expression of the same split that inclines us to deny scientific reality and imagine the human embryo to be anything other than human?
JOSE A. BUFILL is a medical oncologist in South Bend, Indiana. Write to him in care of the Free Press Editorial Page, 600 W. Fort St., Detroit, MI 48226.
July 30, 2001
By Robert P. George, a professor of jurisprudence at Princeton University.
The debate over "harvesting" stem cells from human embryos has forced policy makers to think about a question that they would rather avoid: When does a new human being begin? Of course, this is a question that policy makers should have been thinking about in the context of the debate over abortion. They were relieved of that task by the Supreme Court's misbegotten decision to legalize abortion by judicial fiat. This time no court will let them off the hook.
Still, they are wriggling. White House advisers and members of Congress are looking for a solution or compromise that will enable them to avoid the question whether the destruction of human embryos is in fact the killing of human beings.
They won't find one.
The most recent attempt is by William Frist -- the highly respected pro-life Republican senator from Tennessee who happens also to be an eminent physician. The Frist proposal would ban the funding of research involving the creation of embryos for stem cell harvesting, while permitting the harvesting of stem cells from "excess" embryos created by in vitro fertilization. The argument is: If they will be disposed of anyway, why not make good use of them by dismembering them and obtaining their stem cells?
The trouble with the proposal is that it assumes, on the one hand, that embryos are human beings and therefore should not be brought into being for purposes of destructive research -- no matter how great the possible scientific and medical benefits. Yet it allows the destruction of some embryos.
We would, I hope, never permit or fund the harvesting of organs from retarded human infants, demented or terminally ill patients, or even death row prisoners. It wouldn't matter that death was expected in five months or five minutes. Nor would it matter that a dying patient, for example, was unconscious, even permanently unconscious as a result of a coma. Nor would we factor into our deliberation any consideration of the promise of what science or medicine could do with the organs. We wouldn't tolerate killing for purposes of harvesting body parts because it is inconsistent with the inherent dignity of all human beings.
So there is no avoiding the question: Are embryos, or are they not, human beings?
What is a human being? He or she is a whole, living member of the species Homo sapiens. Plainly gametes (sperm cells and ova) are not human beings. They are parts of other human beings. They lack the epigenetic primordia for internally directed growth and maturation as a distinct, complete, self-integrating, human organism. The same is true of somatic cells (such as skin cells).
Modern science shows that human embryos, by contrast, are whole, living members of the human species, who are capable of directing from within their own integral organic functioning and development into and through the fetal, infant, child, and adolescent stages of life and ultimately into adulthood.
It is not that a human embryo merely has the potential to "become a life" or "become a human being." He or she (for sex is determined at the beginning of life) is already a living human being. In this crucial respect, the embryo is like the fetus, infant, child, and adolescent. The being that is now you or me is the same being that was once an adolescent, and before that a toddler, and before that an infant, and before that a fetus, and before that an embryo. To have destroyed the being that is you or me at any of these stages would have been to destroy you or me.
In the current debate, the question whether a human embryo is a human being is usually ignored or evaded. When it has been faced, the arguments advanced for denying that embryos are human beings have been astonishingly weak. (Understandably, proponents of destructive embryo research have tied to shift the focus to its potential benefits.)
Some commentators say that human embryos don't "look like" human beings. The answer is that they look exactly like the human beings they are, that is, human beings in the embryonic stage of their existence. Others try to make something of the fact that embryos are tiny, or very immature, or dependent for full development upon implantation. Sen. Orrin Hatch has gone so far as to make the location of an embryo -- in a dish or refrigeration unit rather than in a mother's womb -- determinative of its moral status. But anybody who gives the matter some thought should recoil from the idea that factors such as size, stage of development, location, and state of dependency can be a basis for denying rights to human beings.
Then there is the claim that the argument for the human status of the early embryo depends on controversial religious premises about "ensoulment." It does not. The question is not about embryos' eternal destiny. That is a religious matter. (One on which the Catholic Church, by the way, has no official position.) There is no need for those of us who oppose embryo destruction to appeal to religion. The science will do just fine. We would be very pleased if those on the other side would agree that the scientific facts about when new human beings begin should determine whether government should fund research requiring their deliberate destruction.
Of course some proponents of stem-cell research are willing to concede the embryos are human beings. My Princeton colleague Peter Singer and other outright utilitarians deny that there is a principle of inherent human dignity that stands as an absolute bar to killing some people for the sake of a putative "greater good." So they typically see no moral reason not to dismember living embryos for their stem cells. By the same token, they see no moral reason not to kill human beings at any stage of maturity when, as they suppose can happen, some calculus of utility tips the scales in that direction. Hence, Mr. Singer's notorious defense of infanticide of handicapped newborns.
The concept of the "human non-person" -- a human being whose life can be deliberately destroyed, or who can be mutilated or enslaved, to serve the interests of others -- richly deserves the ignominy in which it has come to be held. Let us not accept the devil's bargain of reviving in the mere hope of scientific advances.
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