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Effort to Make Part-Human, Part-Cow Cells Troubles Clinton



        November 15, 1998

        Effort to Make Part-Human, Part-Cow Cells Troubles Clinton

        By NICHOLAS WADE

            Saying that he is "deeply troubled" by the creation of
part-human, part-cow embryonic stem cells,
            President Clinton has directed the National Bioethics Advisory
Commission to consider the
        implications of the research at its meeting Tuesday in Miami and to
report back to him "as soon as
        possible". 

        In a letter sent Saturday to the chairman of the commission, Harold
Shapiro of Princeton University,
        Clinton also asked for a review of embryonic stem-cell research in
general, including the all-human
        embryonic stem cells whose isolation was reported earlier this
month. These cells -- the primordial,
        all-purpose cells from which all tissues of the body develop --
were derived from very early embryos
        or blastocysts and from tissues of aborted fetuses. 

        While the president signaled concern about the "mingling of human
and non-human species," he was
        more positive about the all-human embryonic stem cell research,
noting that it "may have real potential
        for treating such devastating illnesses as cancer, heart disease,
diabetes and Parkinson's disease." 

        But he also stressed the ethical concerns raised by the research,
telling the commission that he wanted
        a "thorough review, balancing all ethical and medical
considerations." 

        The letter was sent after the president had consulted with the
White House Domestic Policy Council
        and the president's science adviser, Neal Lane, "because he wanted
the broadest views possible -- the
        policy people, medical ethicists, as well as the scientists," an
administration official said. 

        A political issue that lies in the background of the commission's
deliberations is the ban on federal
        financing of fetal research. The ban, imposed by Congress, has
created the situation that university
        scientists, who mostly depend on federal money, cannot work on the
human embryonic stem cells
        whereas the private sector may conduct whatever research it pleases. 

        A group of scientists and ethicists known as the Human Embryo
Research Panel said in 1994 that
        research on human embryonic stem cells should be federally
financed, provided that the cells were
        derived from excess pre-implantation embryos created for
infertility treatments. This was the source of
        some of the human embryonic stem cells isolated earlier this month. 

        In response to the panel's report, Clinton said in December 1994,
"I do not believe that federal funds
        should be used to support the creation of human embryos for
research purposes." The statement did not
        rule out research on excess embryos created in infertility clinics
but subsequent action by Congress
        banned all research in which a human embryo is destroyed. 

        Referring to this history, the president said in his letter
Saturday that the ethical issues of human
        embryonic stem cell research had not diminished since his statement
of 1994 but that the benefits had
        become less hypothetical. 

        Lane said the implications of human embryonic stem-cell research
had been under review but news of
        the human-cow hybrid cells, reported last week, "clearly raised
urgent ethical, medical and legal
        issues that the president wants addressed and that's why he asked
for the commission to give it
        immediate attention." 

        Human embryonic stem cells can develop into any of the body's 210
types of cells, a process that
        happens naturally during fetal development. Biologists at Geron,
the company that supported the
        research, hope to grow the cells in the laboratory and guide them
to develop into heart cells, blood
        cells and other tissues. 

        The cells would then be injected into the patient and integrate
with tissues under the control of local
        body signals. 

        In principle, the method could address a range of otherwise
untreatable degenerative diseases, as well
        as relieving the severe shortage of organs available for
conventional transplants. 

        Many serious technical problems remain to be resolved, including
finding ways to guide the stem cells
        down desired paths of development and ways to prevent immune
rejection. 

        The ethical problems are also important because of the source of
the embryonic stem cells. In one case
        the cells came from excess pre-implantation embryos created in
infertility treatments, and in the other
        from aborted fetal tissue. Both sources were legal, but research
using the first would have been
        ineligible for federal money. 

        The human-cow hybrid cell also complied with all laws, said Michael
West, chief executive of
        Advanced Cell Technology of Worcester, Mass., the company that
supported the research. In the
        hybrid cell, the cow cell's nucleus is first removed and the cow
proteins are expected to be rapidly
        replaced with human proteins as the human nucleus takes over the
cell. 

        Although the mingling of species raises many questions, scientists
at Advanced Cell Technology
        regard the operation as one in which the cow egg is used simply to
make the human cell's nucleus
        revert to its embryonic state. As the human cells can be provided
by the patient himself, from blood or
        skin, there is no immune rejection when developed cells grown from
his embryonic state cells are
        injected back into the body. 

        Advanced Cell Technology performed its cow-human hybrid experiment
only once, three years ago,
        and took the study only to a very preliminary stage. Other
scientists say more evidence is needed to
        verify whether embryonic stem-like cells were created. 

        West said he was announcing the research now to test its public
acceptability before making further
        investments in the technique. 

              Copyright 1998 The New York Times Company