X-Message-Number: 37
From: Kevin Q. Brown
Subject: biotech - cloning, fetal cells, and anti-sense
Date: 15 Nov 1988

Cloning
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Cloning is of particular interest to cryonicists for two reasons:
  (1) reanimation from today's cryonic suspension techniques will likely
      require some kind of cloning technology and
  (2) cloning for spare parts may enable one to postpone (or avoid) having
      to undergo cryonic suspension.
Carol Kahn's article "Double Takes" in the Oct. 1988 OMNI (also reviewed in the
Oct. 1988 issue of The Immortalist) outlined the recent history and state of
the art of cloning.  Cloning technology is improving rapidly and, when the
article was written, three mammalian species (cattle, rabbits, and sheep) had
been cloned.  These clones were not derived from adult somatic cells, but
rather by extracting cell nuclei from embryos in the blastocyst stage and
inserting the nuclei into enucleated egg cells.  In general, the more
differentiated a cell becomes, the more difficult it is to clone.  (If,
however, an adult cell can be turned back to an immature cell, perhaps the
technology for cloning adults will soon become available.)
The commercial benefits of cloning (prize) farm animals will be enormous and
the potential benefits of applying cloning technology to humans promise to
become much greater.  For example, salamanders can regenerate lost tails and
starfish and some frogs can regrow limbs.  Perhaps human limbs could be
regenerated either from the remaining stumps or in vitro.  Paul Segall, of the
American Cryonics Society and Trans Time, suggests a simpler and yet more
comprehensive approach than cloning individual appendages or organs: create an
anencephalic clone by removing from the cloned embryo the cells that would have
become the brain and then let the body develop fully (except for the brain).

This non-thinking, non-feeling body will provide spare parts with no possibility

of rejection and when it is used up, another anencephalic clone can be grown for
the next set of spare parts.  (The brain cells may also be preserved, in an
embryonic state, as transplant material for the brain, as described in the
fetal cell research section below.)
Paul Segall and Carol Kahn will soon publish a book (last titled "Living
Longer, Growing Younger").

Fetal Cell Research
-------------------
The cover article of the Nov. 5, 1988 issue of Science News ("Forbidding Fruits

of Fetal-Cell Research") focuses on the ethical issues of implanting brain cells
from human fetuses to treat Parkinson's disease, diabetes, and possibly other
illnesses (such as Alzheimers disease).  This is a political hot potato because

the fetal brain cells are harvested from induced abortions.  Yet no other source
of transplant tissue is quite as promising:
  "Embryonic cells have a number or properties - including their exceptional
  ability to adapt to a new environment, their capacity to stimulate the
  growth of new blood vessels and their unique tolerance to long-term storage -
  that make them ideal as tissue transplants.  Perhaps most important, fetal
  cells are immunologically "naive" - that is, upon being transplanted they
  generally fail to stimulate a rejection response from the recipient's
  immune system."
Of course, future cell culturing and cloning technologies will reduce or
eliminate the need for aborted human fetuses, thereby relieving this political
dilemma (and most likely introducing others).


(The Nov. 5 issue of Science News also had an article titled "Proteins linked to
synaptic 'memory'" concerning recent progress in understanding the proteins
involved in long-term potentiation. [See message #27.])

Anti-Sense Medicine
-------------------
The "Breakthrough" insert of the Dec. 1, 1988 issue of Privileged Information
(Box 10976, Des Moines, IA 50340) reported on a new form of gene therapy called
"anti-sense medicine".  Traditional gene therapy comes in two flavors:
    (1) adding new DNA to generate new proteins and
    (2) replacing "bad" (defective) DNA with "good" DNA.
Anti-sense medicine does not operate directly on DNA.  Instead, an anti-sense
molecule blocks a "bad" gene by binding to its corresponding mRNA, preventing
transcription to a protein.  This is technically much simpler than the two
traditional approaches toward gene therapy.  Possible applications include

treatment for some cancers (such as leukemia) and also a type of herpes simplex.
The article listed several organizations already doing anti-sense medicine
research.
[ How does anti-sense medicine relate to cloning and fetal cell research?
  Maybe some biologists could tell me if the following speculation makes sense:
    If the gene blocked by the anti-sense molecule is one that controls several
    other genes, the effects of the anti-sense medicine could be much more
    wide-ranging than just the presence or absence of a single protein.
    In particular, perhaps anti-sense medicine will someday block the genes
    responsible for controlling cell differentiation and thereby turn an adult
    cell into an immature cell suitable for transplantation or cloning? ]

                                       - Kevin Q. Brown
                                       ...{att|clyde|cuae2}!ho4cad!kqb
                                       

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