Browsing the blog archivesfor the day Friday, July 21st, 2006.


People With One Watch, Part II

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big picture stuff, One Watch, science, stem cells

This is a continuation of the previous post. I want to look at elective ignorance and the stem cell controversy. However, there are some basic points I want to clarify in this post before I go on to the main point.

“Embryonic” stem cells are derived from the cells that make up the inner cell mass of a blastocyst. Although sometimes a blastocyst is described as an embryo in a very early stage, in fact it is a conceptus in a pre-embryonic state. In humans, a blastocyst develops in the fallopian tube from the fertilized egg (zygote) and then moves (usually) to the uterus, where it implants itself. A pregnancy begins with the implantation of the blastocyst, which then develops into an embryo.

Embryonic stem cells are controversial because acquiring new cells requires destroying a blastocyst. Research scientists want to use the excess blastocysts stored at in vitro fertilization clinics that are going to be destroyed anyway, so there is no need to fertilize an egg for the purpose of obtaining stem cells. Those who object say the blastocyst is a human life, so destroying it is murder. Eventually embryonic stem cells for research may be obtained by cloning, which of course is controversial also.

For the most part, blogosphere opinion on embryonic stem-cell research splits across right-left lines, with the occasional exception. The Right is certain that conducting embryonic stem cell research is immoral. The Left is certain that not conducting embryonic stem cell research is wasteful, and I would call it immoral. To the Left, the Right’s arguments are silly. To the Right, the Left’s arguments are sinister.

As many on the Right point out, the President’s recent veto of the stem cell bill does not result in a ban on embryonic stem cell research, but maintains a ban on federal funding for research. Research with other funding can still be conducted. There is even an exception — embryonic stem cell lines that already existed before August 2001 can be used in federally funded research. And federal funding is available for research on adult stem cells. The Right believes federal policy is an acceptable compromise.

The Left points out that the stem cell lines available for federally funded research have been contaminated with mouse cells, which limits their use. The Left argues also that the ban on federal funds is close to a de facto ban. As this PBS Nova report points out,

Most basic biomedical science in this country—the early, exploratory research—is funded by federal dollars, with the National Institutes of Health taking the lead (to the tune of $20 billion in research-related funding a year). Scientists say that no field of research can flourish without access to this kind of government support. Yet the Harvard scientists you’ll meet in our NOVA scienceNOW segment are barred from using federal funds for the research we describe. If they already head government-funded labs, none of the equipment they’ve purchased can be used to create brand new human embryonic stem cells, to work with any such cells created after 2001, or to create cloned human embryos for stem cell research. That means not a microscope, not a petri dish, not one glass beaker. Scientist Doug Melton, who receives private funds from the Howard Hughes Medical Institute, has gone so far as to equip an entirely separate lab, at an undisclosed location, for this work.

From the American Society on Hematology:

With fewer opportunities for federal funding in human embryonic stem cell research, private sector and state efforts are gaining prominence, outside of the federal government’s oversight, control, and peer review mechanisms. Furthermore, several foreign countries are encouraging and/or actively investing in stem cell research, thereby posing the potential threat of loss of American scientific prominence in this emerging field, possible emigration of the best and brightest American scientists, and definite diminution in the number of talented foreign graduate students, postdoctoral fellows, and senior scientists who otherwise would come to the US for their training and to conduct research in this important area of scientific inquiry.

Adult stem cells can be taken from many parts of a human body, but most come from bone marrow. Contrary to claims from the Right, adult stems cells are not a substitute for embryonic stem cells. Both types of stem cells hold therapeutic promise, but not the same promise. Adult and embryonic stem cells have different properties and different potentials. According to the International Society for Stem Cell Research, embryonic stem cells are pluripotent, meaning they can be developed into many types of cells. Adult stem cells have so far not been found to have this property. On the other hand, adult stem cells have been used successfully to treat blood disorders. There is ongoing research into their use in treating breast cancer, coronary artery diseases, and other conditions. Adult stem cell research is important, also, but claims that adult stem cells have the same potential as embryonic stem cells are simply not true, based on research so far.

Another difference is that, once established in culture, large numbers of stem cells from embryos can be grown for a long time — indefinitely, under the right circumstances — and these cells will retain their unique properties. This is not true of adult stem cells. Stem cells are also obtained from umbilical cord blood and the pulp under baby teeth, and these cells may survive culturing longer than adult cells. These cells haven’t yet been found to have the same pluripotent quality of embryonic cells.

Some on the Right claim there is no evidence whatsoever that embryonic stem cells hold any therapeutic promise. This claim is based on cherry-picked “facts” — see for example, this web page featuring some quotes pulled from newspaper articles — e.g., “Not a single embryonic stem cell has ever been tested in a human being, for any disease”; “‘No one in human embryonic-stem cells will tell you that therapies are around the corner”; etc. In fact, human embryonic stem cells have been successfully turned into insulin-producing cells, blood cells and nerve cells. As reported by Maggie Fox of Reuters (July 16):

“They hold promise in different areas today,” said David Meyer, co-director, of the Cedars-Sinai International Stem Cell Research Institute, which is set to formally open in Los Angeles on Monday

“Adult stem cells will lead to cures much sooner than embryonic. However, the potential for embryonic, once we understand the biology, will be the greater,” Meyer said in a telephone interview.

Groups such as the Juvenile Diabetes Research Foundation and the American Association for Cancer Research say work with embryonic stem cells is vital to understanding how to regenerate diseased or damaged cells, tissues and organs.

For example:

— On July 3, a team at the University of California at Los Angeles reported they had transformed human embryonic stem cells into immune cells known as T-cells — offering a way to restore immune systems ravaged by AIDS and other diseases.

— In June, a team at Johns Hopkins University in Baltimore transplanted stem cells from mouse embryos into paralyzed rats and helped them walk again. Researchers at the University of California at Irvine have done similar work using human embryonic stem cells in rats.

Weirdly, people opposed to embryonic stem cells on moral grounds often are compelled to lie about the research:

David Prentice of the Family Research Council, which opposes embryonic stem-cell research, issued a statement saying adult stem-cell research was actively helping, or close to helping, people with at least 65 diseases.

But in Friday’s issue of the journal Science, three stem-cell experts — Steven Teitelbaum of Washington University in St. Louis, Shane Smith of the Children’s Neurobiological Solutions Foundation in Santa Barbara, California and William Neaves of the Stowers Institute for Medical Research in Kansas City — wrote a detailed rebuttal of these claims and said at best Prentice accurately portrayed only nine of the studies.

What does it say when people lie to defend an opinion on morality?

Right now preclinical work with embryonic stem cells is moving slowly through animal testing, and there are some obstacles to overcome before human trials begin. It is true that one human trial on Parkinson’s Disease patients was stopped in 2001 when 15 percent of the patients developed side effects that were worse than the Parkinson’s. This illustrates the need for caution. However, preclinical research on embryonic stem cells and Parkinson’s disease continues and is showing some promise.

Some argue that because research on embryonic stem cells has yet to result in treatment for human disease, the research is worthless. They ignore the fact that embryonic stem cells were first isolated in 1998. Research on embryonic stem cells is still at an early stage. Studies on adult stem cells, on the other hand, began in the 1960s.

Most medical breakthroughs take a long time to develop. Researchers began trying to develop a polio vaccine in the early 1900s. Jonas Salk began his research in 1947. Human clinical trials began in 1954. The safer Sabine vaccine became available in 1963. It took this much time just to develop a safe and effective vaccine, which is something that had been done successfully before. Developing any new therapy takes time and is terribly expensive — “discovering, testing, and manufacturing one new drug can take between 10 and 15 years and cost nearly a billion dollars.” Stem cell therapy is a far more complex project than developing a new drug.

The naysayers are, essentially, arguing that because the research hasn’t yet developed therapies for human use it never will, even though the enormous majority of scientists believe otherwise.

Here’s one interesting story, however

The story of Molly Nash illustrates how stem cell tools and therapies can work together to save lives. The Colorado child was born with Fanconi’s anemia, a genetic blood disease with an especially poor prognosis. Most patients rarely reach adulthood and die of leukemia. A bone marrow transplant from a healthy sibling with a matched HLA or immune profile can cure the disease, but Molly was an only child and her parents — both carriers of the deadly gene — were fearful of having another child with the disease. They used in vitro fertilization, pre-implantation diagnosis and a cord blood transplant in an attempt to save their child. PGD was used to screen 24 embryos made in the laboratory. One embryo was disease-free and matched Molly’s immune profile. The blastocyst was implanted and nine months later her sibling, named Adam, was born. The stem cells from Adam’s umbilical cord were given to Molly and today she is eleven years old and free from disease.

You can argue about the ethics of having a baby to obtain an umbilical cord to save a child if you like, but this case illustrates that the potential for stem cell therapies are very real.

There is a lot of confusion over stem cell cloning. When stem cell researchers talk about cloning, they mean therapeutic cloning, not reproductive cloning. In therapeutic cloning the cloned cells do not develop into an embryo but instead are used only to develop stem cells.

One other point — a South Korean scientist recently admitted to faking research on stem cell cloning. After this became news, a few on the Right came to believe that all research on embryonic stem cells throughout space and time was, therefore, faked. This is nonsense.

Of course, if the stem cells in question didn’t involve destroying blastocysts, there’d be no controvery. Which takes us back to the leftover blastocyst question.

Opponents of embryonic stem cell research argue that most embryos could be implanted in a uterus someday, which is absurd when you consider the cost and time and the fact that the number of blastocysts in storage is growing rapidly. Liza Mundy writes in the current issue of Mother Jones:

In 2002, the Society for Assisted Reproductive Technology—the research arm for U.S. fertility doctors—decided to find out how many unused embryos had accumulated in the nation’s 430 fertility clinics. The rand consulting group, hired to do a head count, concluded that 400,000 frozen embryos existed—a staggering number, twice as large as previous estimates. Given that hundreds of thousands of ivf treatment rounds have since been performed, it seems fair to estimate that by now the number of embryos in limbo in the United States alone is closer to half a million.

This embryo glut is forcing many people to reconsider whatever they thought they thought about issues such as life and death and choice and reproductive freedom. It’s a dilemma that has been quietly building: The first American ivf baby was born in 1981, less than a decade after Roe v. Wade was decided. Thanks in part to Roe, fertility medicine in this country developed in an atmosphere of considerable reproductive freedom (read: very little government oversight), meaning, among other things, that responsibility for embryo disposition rests squarely with patients. The number of ivf rounds, or “cycles,” has grown to the point that in 2003 about 123,000 cycles were performed, to help some of the estimated 1 in 7 American couples who have difficulty conceiving naturally. Early on, it proved relatively easy to freeze a lab-created human embryo—which unlike, say, hamburger meat, can be frozen, and thawed, and refrozen, and thawed, and then used. (To be precise, the technical term is “pre-embryo,” or “conceptus”; a fertilized egg is not considered an embryo until about two weeks of development, and ivf embryos are frozen well before this point.) Over time—as fertility drugs have gotten more powerful and lab procedures more efficient—it has become possible to coax more and more embryos into being during the average cycle. Moreover, as doctors transfer fewer embryos back into patients, in an effort to reduce multiple births, more of the embryos made are subsequently frozen.

And so, far from going away, the accumulation of human embryos is likely to grow, and grow, and grow.

The cold truth is that blastocysts generated in IVF clinics and not implanted into a uterus are often discarded immediately. Most of the blastocysts that are frozen will either degrade or be discarded eventually. A small number of available blastocysts have been implanted into adopting mothers, creating the “snowflake babies” — 110 have been born so far. A large portion of the blastocysts that are thawed and implanted will fail to result in a baby, however.

It should be obvious to anyone thinking clearly that “embryo adoptions” are not going to be the solution to the growing glut of frozen blastocysts. And if destroying a blastocyst is immoral, why is it more immoral to use it for potentially life-saving medical research than it is to send it straight to an incinerator? This makes no sense to me.

Now I can finally write about what I wanted to write about to begin with, which is looking at the “moral” issue of embryonic stem cells from many perspectives. I’m going to argue tomorrow that there is nothing at all immoral about embryonic stem cell research, but it is deeply immoral to deny medical researchers the use of surplus blastocysts.

Also: Alternet, “Stem Cell Research Could Make Miracles Happen“; Bob Geiger, “Right wing should adopt 400,000 frozen embryos.”

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