[Congressional Record Volume 151, Number 105 (Thursday, July 28, 2005)]
[Senate]
[Pages S9215-S9217]
From the Congressional Record Online through the Government Publishing Office [www.gpo.gov]
STEM CELL LEGISLATION
Mr. BROWNBACK. Mr. President, I rise this morning to address some of
the comments that have been made on the other side of the aisle
regarding the Castle bill on embryonic stem cell research that passed
in the House a few weeks ago: I have heard the proposal this morning
from my colleagues from the other side that we should discuss and talk
about embryonic stem cell research and the proposed umbilical cord
blood bill that have been put on the calendar here in the Senate, but
without any discussion about human cloning. I want to try to put this
issue in context a little, and to propose some factual information.
Mr. President, we need to have a broad discussion about bioethical
issues in this body and all across the country, and it needs to involve
the full range of issues that have come to light as we attempt to grasp
the implications and come to understand the decisions that must be made
in this challenging area.
This discussion should involve cord blood stem cells. These types of
cells are stem cells that come from the umbilical cord when a child is
born; they are a rich source of pluripotent stem cells that have proven
very helpful in providing a number of treatments for humans.
We need to continue to talk honestly about embryonic stem cell
research: the possible limitations of this research to cure diseases in
humans, as well as the certain destruction of embryos that this type of
research necessitates.
We need to talk about human cloning, whether or not we want to
continue to allow the practice of cloning to take place in the United
States of America (it is currently a legal process in this country, to
clone, create and kill an embryo, a young human).
We need to talk about the cutting edge related research applications,
we need to consider where the science is leading us on issues such as
the creation and manipulation of chimeras--human-animal crosses that
are created by, for instance, taking human brain cells and putting them
in a mouse--we cannot bypass these critical issues in this discussion.
And we need to talk about some exciting new application prospects of
these broad-based pluripotent cells, cells that can do virtually
anything--but I speak of cells where it is not necessary to extract
them from a human embryos, destroying that embryo in the process, but
cells yielded from other places in the body.
With this background in mind, I want to point out a couple of quick
facts.
No. 1, Mr. President, I ask unanimous consent to have printed in the
Record, from this morning's Washington Post, an article describing new
revelations about pluripotent adult stem cells that can answer many of
these questions. I ask that the article be included and printed at the
conclusion of my remarks.
The PRESIDING OFFICER. Without objection, it is so ordered.
(See exhibit 1.)
Mr. BROWNBACK. Mr. President, I wish to read one section of this
article:
A team of Harvard scientists is claiming the discovery of a
reservoir of cells that appear capable of replenishing the
ovaries of sterilized mice, possibly providing new ways to
[create human eggs].
Adult stem cells in the body with the ability to create human eggs.
Now, people may say: What do you mean by that? Well, here we have a
pluripotent adult stem cell (derived from bone marrow) with a broad
capacity to create a lot of different cells, so much so that they can
generate, when placed in the right place in the body--a woman's ovary--
human eggs.
Listen to what the scientists here say about this:
In addition, because the cells appear to be a particularly
versatile type of adult stem cell--
I would like to pause for a moment to point out that there are no
ethical problems or objections to research conducted with adult stem
cells. We should put millions of dollars into this type of research.
This type of research is yielding cures--65 treatment applications for
humans with adult stem cell research. However, I'd like to conclude the
reading of this excerpt:
. . . a particularly versatile type of adult stems cells
[which] could provide an alternative to those obtained from
embryos, avoiding the political and ethical debates raging
around the use of those cells.
End of quote, in this morning's Washington Post, from Harvard
researchers.
Mr. President, I ask then, why would we want to kill young human
embryos, young humans, who are clearly alive, who are clearly human,
when we have the capacity, in adult stem cells, to conduct useful and
productive research to cure diseases, that is not hindered by ethical
problems?
In an article from this month's The Lancet--a well-respected British
medical journal--Mr. President, I ask unanimous consent that the
article be printed in the Record at the conclusion of my remarks.
The PRESIDING OFFICER. Without objection, it is so ordered.
(See exhibit 2.)
Mr. BROWNBACK. The author of this editorial--this is the lead British
medical journal--says:
. . . what is unarguable is that the human embryo is alive
and is human, and intentionally ending the life of one human
being for the potential benefit of others is not territory to
which mainstream clinical researchers have hitherto sought
claim--or which ethically conscientious objectors could ever
concede.
These embryos are alive. They are alive. They are human.
I want to conclude, because time is very limited--Mr. President: I
want cures for people. I want cures for juvenile diabetes, for cancer,
for spinal cord injuries, for Parkinson's disease. And, with research
generated from pluripotent adult stem cells, we are getting these
treatments.
Mr. President, I ask unanimous consent to have printed in the Record
a list of human clinical trials going on now, using adult or cord blood
stem
[[Page S9216]]
cells, involving no ethical dilemmas, for 65 different human maladies.
The PRESIDING OFFICER. Without objection, it is so ordered.
(See exhibit 3.)
Mr. BROWNBACK. The number of areas of treatment for human ailments or
medical conditions in humans using human embryonic stem cells is zero.
So the notion that delaying this Castle-Specter bill is going to hurt
current patients is completely false. If we want to help current
patients, the key--the key--is to put more research into adult and cord
blood stem cell research. If you want to help current patients, you
should be ever so careful not to promise impossibilities to these
hurting individuals; you should state what the scientists are telling
us, that the possibility of embryonic stem cells yielding cures, if
ever--and I really doubt if it ever happens--is decades away. And we
have had problems in the past with these types or cells forming
dangerous and cancerous tissues--a problem which has not yet been
worked out. If we want cures, let's go the route where we know we are
going to reach our destination, and where we know treatment is true
possibility.
Mr. President, I yield the floor.
Exhibit 1
[From the Washington Post, July 28, 2005]
Scientists Claim To Find Cells That Restore Egg Production
(By Rob Stein)
A team of Harvard scientists is claiming the discovery of a
reservoir of cells that appear capable of replenishing the
ovaries of sterilized mice, possibly providing new ways to
help infertile women have babies.
While cautioning that more research is needed to confirm
that similar cells exist in women and that they can safely
restore fertility, the researchers said the findings could
revolutionize the understanding of female reproduction and
the power to manipulate it.
``This may launch a new era in how to think about female
infertility and menopause,'' said Jonathan L. Tilly, a
reproductive biologist at Harvard Medical School and
Massachusetts General Hospital in Boston who led the
research. It is being published in tomorrow's issue of the
journal Cell.
Other researchers agreed that the findings could have
profound implications, but several expressed caution and
skepticism, saying many key questions remain about whether
the researchers have proved their claims.
``This is really exciting and a revolutionary idea. The
implications are potentially huge,'' said Lawrence Nelson of
the National Institute of Child Health and Human Development.
``But before this could have any type of application to
humans, a whole lot of work has to be done. We have to be
careful not to get ahead of ourselves.''
But Tilly said he was confident of his findings, which
could, for example, enable women to bank egg-producing cells
when they are young in case they have health problems that
leave them infertile or they get too old.
``In theory, these cells could provide an insurance policy.
We could harvest them and store them away for 20 years. Then
you put them back in, and they are going to do exactly what
they are supposed to--find the ovaries and generate new
eggs'' to restore fertility, Tilly said.
The discovery could also lead to ways to prevent, delay or
reverse menopause, perhaps by stimulating dormant cells in
the bone marrow or ``tweaking'' the ovaries to accept them,
Tilly said. It may also be possible to transplant them from
one woman to another, he said.
In addition, because the cells appear to be a particularly
versatile type of adult stem cell, they could provide an
alternative to those obtained from embryos, avoiding the
political and ethical debates raging around the use of those
cells.
``The implications are mind-boggling, really,'' Tilly said.
The research is a follow-up to results the team reported in
March 2004, when it claimed it had shown that mice can
produce eggs throughout their lives. For decades, scientific
dogma has been that female mammals such as mice and humans
are born with a finite number of eggs. To alleviate doubts
about their original claim, the researchers conducted another
round of experiments, which they said confirm the findings
and explain how it might work.
First, the scientists sterilized female mice with a cancer
chemotherapy drug that destroyed eggs in the ovaries but
spared any egg-producing cells elsewhere. They tested the
animals' ovaries 12 to 24 hours later and found signs their
egg supply was rapidly regenerating. Two months later, the
animals' ovaries looked normal, and they remained that way
for life.
After tests indicated the source of the cells may lie in
the animals' bone marrow, the researchers infused marrow from
healthy mice into those that were either genetically
engineered to be infertile or had been made infertile with
chemotherapy. Two months later, the recipients' ovaries
looked normal, whereas those that had not received the
transplants remained barren, the researchers reported. Blood
transfusions produced similar results, they said.
The researchers then infused blood into infertile mice from
animals that had been genetically engineered so that their
reproductive stem cells glowed fluorescent green. Within two
days, green egg cells appeared in the recipients' ovaries,
which the researchers said indicated the cells had traveled
through the blood to the ovaries.
Finally, the researchers screened human bone marrow and
blood from healthy women and found that both tested positive
for biological markers indicating the presence of immature
reproductive cells.
``Mice and humans appear to be the same--they appear to
have a set of genes in bone marrow consistent with . . .
cells that can make themselves a new egg,'' Tilly said.
The findings could help explain previously mysterious cases
of women sterilized by cancer treatment who spontaneously
became pregnant after receiving bone marrow transplants,
Tilly said. This may happen only rarely because some, but not
all, techniques used to process bone marrow before
transplantation may destroy the cells in some cases, he
speculated.
The research triggered a mixture of excitement, caution and
deep skepticism.
``It's quite amazing,'' said Hans Schoeler of the Max
Planck Institute in Germany. ``The idea that cells from bone
marrow may be a reservoir for egg cells would be quite
astonishing.''
But Schoeler and other researchers cautioned that many
crucial questions remained. Several researchers had doubts
about some of the techniques the researchers used. Others
were puzzled by the speed with which the ovaries appeared to
be repopulated with eggs. Many pointed out that the
researchers had failed to show the eggs were viable, the mice
were ovulating or that they could give birth to healthy
offspring.
``I'm very skeptical,'' said David F. Albertini of the
University of Kansas Medical Center in Kansas City, Kan.
``There are a lot of holes in the research.''
Tilly attributed the skepticism to the radical nature of
the findings and said he already had work underway to address
the concerns, including breeding studies aimed at producing
healthy offspring.
``We hope we will have the answers very soon,'' Tilly said.
____
Exhibit 2
Stem-Cell Therapy: Hope and Hype
In the fifth year since human cloning to generate stem
cells was legalised in the UK, what progress has been made
towards taking stem-cell therapy from laboratory to clinical
practice? In 2000, articulating robust UK Government support,
then Health Minister Yvette Cooper proclaimed that stem cells
from cloned human embryos ``could prove the Holy Grail in
finding treatments for cancer, Parkinson's disease, diabetes,
osteoporosis, spinal cord injuries, Alzheimer's disease,
leukemia and multiple sclerosis . . . transform[ing] the
lives of hundreds of thousands of people''. But 4 years
later, the technical difficulties and biological hazards
inherent in cloning human embryos and developing treatments
from their stem cells led Richard Gardner, Chairman of the
Royal Society Working Group on Stem Cells and Therapeutic
Cloning, to doubt whether this would ever be a ``a procedure
that becomes widely available . . . There are concerns about
the efficiency and elaborateness of the procedure, and it's
going to be very time-consuming and very expensive''. So, to
paraphrase May 25th's Saving Faces event in London, UK, are
stem-cell therapies hype, or hope, or substance?
Only two UK groups currently seek to clone human embryos,
both with immediate aims not of developing therapies but of
improving understanding of embryonic development or specific
diseases. Techniques for culturing human embryonic stem cells
have advanced--e.g., allowing them (like adult stem cells) to
be grown--but an increasing appreciation of the hazards of
embryonic stem cells has rightly prevented the emergence or
immediate prospect of any clinical therapies based on such
cells. The natural propensity of embryonic stem cells to form
teratomas, their exhibit of chromosomal abnormalities, and
abnormalities in cloned mammals all present difficulties.
The prospect of having to clone (to obtain embryonic stem-
cells) every patient requiring therapy is surely unrealistic
(the Korean report of cloning human embryos for stem cells
used almost 250 human eggs in generating a single stem-cell
line). If cloning is unrealistic and/or too hazardous, the
autologous advantage of (cloned) embryonic stem cells
vanishes: and immune rejection of embryonic stem cells
generated from ``foreign'' in-vitro fertilisation or abortion
presents further problems.
These biological problems only add to the ethical
objections. The Lancet declared in 2001 that: ``the creation
of embryos solely for the purpose of producing human stem
cells is not only unnecessary but also a step too far''.
Semantic questions about embryology and personhood are
interesting, if unprovable, but what is unarguable is that
the human embryo is alive and is human, and intentionally
ending the life of one human being for the potential benefit
of others (i.e., for research) is not territory to which
mainstream clinical researchers have hitherto sought claim--
or which ethically conscious objectors could ever concede.
So is stem-cell research a damp squib, another over-hyped
funding gambit? Far from it, for the embryonic stem-cell
story forms only one aspect. Excitement about the potential
of adult stem cells was tempered by
[[Page S9217]]
reports in 2002 that in some circumstances such cells can
fuse. Fusion might give a false appearance of
metadifferentiation, the argument ran, therefore adult stem
cells are not really multipotent, and are a nonstarter as an
alternative to embryonic stem cells.
Fortunately, for the now highly expectant patient, reports
of the death of adult stem cells were greatly exaggerated.
Much research (some indeed antedating the fusion excitement)
clearly shows that although fusion can and does occur in
certain tissues, adult (say) bone-marrow-derived stem cells
can also generate multiple lineages without cell fusion.
Interestingly, fusion may be an unexpected mechanism of
achieving repair, and could additionally offer means of
delivering gene therapy. Normal (bone-marrow-derived) donor
nuclei were found in the muscle of a patient with Duchenne
muscular dystrophy, over a decade after bone-marrow
transplantation for immune deficiency, offering proof of
principle for fusion of bone-marrow-derived stem cells as
gene therapy, and presenting tantalising therapeutic
prospects. Also, it is now clear that aneuploidy represents a
not uncommon, spontaneous, and normal process, rather than
necessarily carrying sinister implications, as speculated.
Suggestions of low rates of differentiation of bone-marrow-
derived stem cells and integration in situ, and of
questionable differentiation, have also been addressed.
Perhaps the most compelling (and extraordinary) evidence
unambiguously confirming the ability of adult bone-marrow-
derived stem cells not only to metadifferentiate but also to
integrate fully into adult (human) organs, and survive for
decades, comes from postmortem studies of sex-mismatched
recipients of bone-marrow transplants, showing donor-derived
fully differentiated neuronal cells of a highly complex
morphology apparently fully functionally established within
the host brain, with no evidence of fusion.
We now know that bone marrow-derived stem-cells circulate
systemically and actively migrate into damaged tissue to
contribute to spontaneous repair. Experimentally, therapeutic
benefit occurs in numerous disease models but, importantly,
repair by bone-marrow-derived stem cells does not stop at the
laboratory door. Safety data from 50 years of clinical bone-
marrow transplantation, during which nonhaemopoetic stem
cells have inadvertently also been transplanted, and the
accompanying clinical expertise in collecting, handling,
freeze-storing, thawing, and delivering marrow, have safety
allowed a rapid translation of bone-marrow-stem-cell science
from laboratory to clinic. Controlled trials have shown
significant benefit of marrow-derived stem-cell therapy in
myocardial infarction, and trials are planned or underway in
chronic cardiac failure, stroke, and other diseases: reports
of successful adult stem-cell therapy in myocardial
infarction, and trials are planned or underway in chronic
cardiac failure, stroke, and other diseases: reports of
successful adult stem-cell therapy in patients with corneal
disease have just appeared. The next few years, not decades,
will show whether adult stem-cell treatments are to join the
mainstream therapeutic arsenal.
____
Exhibit 3
Benefits of Stem Cells to Human Patients--Adult Stem Cells v. Embryonic
Stem Cells (Published Treatments in Human Patients)
adult stem cells: 65--escr:0
Cancers
1. Brain Cancer
2. Retinoblastoma
3. Ovarian Cancer
4. Skin Cancer: Merkel Cell Carcinoma
5. Testicular Cancer
6. Tumors abdominal organs Lymphoma
7. Non-Hodgkin's Lymphoma
8. Hodgkin's Lymphoma
9. Acute Lymphoblastic Leukemia
10. Acute Myelogenous Leukemia
11. Chronic Myelogenous Leukemia
12. Juvenile Myelomonocytic Leukemia
13. Cancer of the lymph nodes: Angioimmunoblastic
Lymphadenopathy
14. Multiple Myeloma
15. Myelodysplasia
16. Breast Cancer
17. Neuroblastoma
18. Renal Cell Carcinoma
19. Various Solid Tumors
20. Soft Tissue Sarcoma
21. Waldenstrom's macroglobulinemia
22. Hemophagocytic lymphohistiocytosis
23. POEMS syndrome
Auto-Immune Diseases
24. Multiple Sclerosis
25. Crohn's Disease
26. Scleromyxedema
27. Scleroderma
28. Rheumatoid Arthritis
29. Juvenile Arthritis
30. Systemic Lupus
31. Polychondritis
32. Sjogren's Syndrome
33. Behcet's Disease
34. Myasthenia
35. Autoimmune Cytopenia
36. Systemic vasculitis
37. Alopecia universalis
Cardiovascular
38. Heart damage
Ocular
39. Corneal regeneration
Immunodeficiencies
40. X-Linked hyper immunoglobuline-M Syndrome
41. Severe Combined Immunodeficiency Syndrome
42. X-linked lymphoproliferative syndrome
Neural Degenerative Diseases/Injuries
43. Parkinson's disease
44. Spinal cord injury
45. Stroke damage
Anemias/Blood Conditions
46. Sickle cell anemia
47. Sideroblastic anemia
48. Aplastic Anemia
49. Amegakaryocytic Thrombocytopenia
50. Chronic Epstein-Barr Infection
51. Fanconi's Anemia
52. Diamond Blackfan Anemia
53. Thalassemia Major
54. Red cell aplasia
55. Primary Amyloidosis
Wounds/Injuries
56. Limb gangrene
57. Surface wound healing
58. Jawbone replacement
59. Skull bone repair
Other Metabolic Disorders
60. Osteogenesis imperfecta
61. Sandhoff disease
62. Hurler's syndrome
63. Krabbe Leukodystrophy
64. Osteopetrosis
65. Cerebral X-linked adrenoleukodystrophy.
The PRESIDING OFFICER. The Senator's time has expired.
____________________