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The fundamentals of life
Life has a very, very long history, but each of us has a very precise
beginning : the moment of the conception. The progeny and the parents are
constantly, united by a material link, the threadlike molecule of DNA, upon
which the complete genetic information is written in a fantastically
miniaturized language.
On the head of a spermatozoon, there is a one meter length of DNA,
cut in 23 pieces. Each segment is very precisely coiled to form little rods
visible With an ordinary microscope : the chromosomes.
As soon as the sperm has perforated the "zona pellucida", the plastic
bag inside which the ovum is wrapped, the membrane becomes suddenly
impenetrable to any other sperm. In purely operational terms, it can be stated
that as soon as the 23 paternal chromosomes carried by the sperm are put in the
same bag as the 23 maternal chromosomes (carried by the ovum), the total
information necessary and sufficient to dictate the genetic make-up of the new
human being is gathered. Not a theoretical or a potential human type, but the
very human being we will later call Peter, Paul or Magdalene.
Exactly as introducing a mini-cassette inside a tape recorder will
allow the playingof a symphony, the music of the life is played by the
machinery of the cytoplasm, and the new human begins to express himself as soon
as he has been conceived.
Soul and body or spirit and matter are so intricately interwoven at
the beginning of life that we use the same Word, conception, to describe the
process by which an idea, a concept, comes into our mind, and to define the
genetic process by which a new being, a conceptus, comes to life.
Protected in its life capsule (the zona pellucida first, then the
amniotic bag he constructs around himself) the early human being is just as
viable and autonomous as a cosmonaut on the moon : refueling with vital fluids
is required from the mother vessel. No artificial fluid supplier has yet been
invented ; shelter and nurture by the mother organism are absolutely
required.
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Congenital abnormalities
Two types of misfortunes, inborn or acquired, can hamper the future.
At the very beginning, an unequitable patrimony could darken the destiny.
A misspelling of the genetic message (a "mutation" like
phenylketonuria) or a mistake in the binding of the volumes of the tables of
the law of life (a chromosomal aberration like trisomy 21) could curb the
embryological process or modify chemical reactions. Affected in his flesh
and/or in his mind, the child will suffer of a physical and/or mental
impairment.
Secondarily, because of the length (9 months) and of the complexity of
this construction period, any assault can be deleterious (be it a viral
infection, a chemical aggression or an inadequate nutrients supply). A child
concieved per fectly healthy, can thus acquire physical or mental
disalibilities in utero : post rubeolic malformations or neural tube defects
like Spina bifida or anen-kephaly.
It follows that if a child is found carrier of an inborn anomaly, or
of a developmental difficulty, its destiny can be predicted with an appreciable
accuracy.
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Prevention or destruction : quo vadis ?
Acquired abnormalities can be prevented : vaccination of young girls
against rubella will protect the future babies and in the case of neural tube
defects, the remarkable achievements of Smithells (1) has shown that folic acid
given to the would be mother could diminish by a factor of ten, the risk of
this disastrous malformation of the nervous systems.
On the same way, some exceptional cases of inborn errors can be
adequatly managed in utero. For example, Methyl cobalamin deficiency can be
compensated by vitaminotherapy of the pregnant mother (2) or, rhesus foeto
maternal incompatibility can be prevented by "vaccination" of an at risk mother
or treated by exsanguino transfusion of the baby even in the womb.
But in the overwhelming majority of cases, no efficient protective
answer is available.
Nowaday, amniocentesis, chorionic biopsy, or advanced imagery allow
early detection of various afflictions, but the avowed purpose of these
prenatal diagnosis is to eliminate by abortion the affected babies. Even in
case of twin pregnancies, some have selectively killed the affected twin in
utero (3) and in case of unwanted quintuplet pregnancy, have even killed by
cardiac puncture three out of the five foetuses (4).
Health by death is a desperate mockery. The complete history of
medicine is on hand to show that those who delivered humanity from plague and
rabies were not those who burned the plague stricken alive in their houses or
suffocated rabid patients between two mattresses. The only possible victory of
medicine is over the disease, not over the patient.
Some technicians are even requesting the right to experiment on human
embryos produced by in vitro fertilization. They say this will help them to
understand, to prevent, and possibly cure very terrible genetic disabilities
like hemophilia, muscular dystrophy, cystic fibrosis or Down's syndrome.
Three years ago I had the honor of explaining to members of the
British Parliament that research on those diseases could not be performed at
all on human embryos less than 14 days old for a very decisive reason : at this
stage of development, the relevant organs (brain for mental retardation,
pancreas for cystic fibrosis, muscle for muscular dystrophy, or blood-forming
organs for hemophilia) are not yet developed.
Considered as a "french influence in Britain" (5) such a matter of
fact statement was severly criticized by the promoters of experiments on human
embryos. An appeal to embryologists (6) requested protocols showing
convincingly that human embryos (no animal embryos) were absolutly
requested.
Nearly there years later, no such protocol has been published !
On the contrary an advanced country, especially aware of the dangers
of indulging experimentation on man, West Germany, is considering a law
protecting the early human beings from any exploitation (7).
The very question is not to express a wish full statement that "embryo
research may, in due course, enhance the same ideal, perhaps by helping to rid
people of undignifying genetic diseases" (8) but to realise that we "are a long
way from curing anyone of a genetic disease, but have already begun ridding
ourselves of PEOPLE, with what we consider "undignifying genetic diseases",
through abortion and euthanasia" (9).
Thöse recent quotations show how appropriate it is to ask Quo Vadis :
where areth thou going ?
Should we accept the repeated leitmotiv that a full respect of the
human nature is an out of fashion taboo and, frankly speaking, that moral is an
impediment to discovery ? The very recent developments of molecular biology are
confirming again and again that no good science has ever been builded on
contempt of human dignity.
During the last three years, thanks to the work of many different
researchers in many countries, the genes of cystic fibrosis (10) and of
Duchenne's muscular dystrophy (11) have been found and cloned, as well as those
of Huntington's Chorea (12) and of retinoblastoma (13). Even the specific
protein of muscular dystrophy the "dystrophin" is now identified and analysed
(14). For hemophilia, the special coagulation factor is now manufactured by
manipulated bacterias so that patients can be treated with a pure product
without any risk of transmission of AIDS through contaminated blood !
All these successes since 1985 have been obtained without endangering
human embryos at all. And none of the experiments were in contradiction with
the absolute respect of each and every human being, from conception to natural
death, which has always been the guideline of civilized scientists.
In this context, it is worth quoting the solemn declaration of 15
research workers of the Max Planck Institute "The abuse of these techniques
through experiments with human embryos (or pre-embryos, if one considers a
preimplantation embryo not to be an embryo) must be condemned by the scientific
community" (15).
It is conforting that scientists living in a country in which the
denatured biology at the nazis was once the legal doctrine, are thus restoring
the dignity of biology as an honest servant of true medicine.
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Toward a rehabilitation medicine
Two ways are broadly open : First the dechiphering of the abnormal
gene products (like the dystrophin already quoted) will allow to understand
their action and to find means of alleviating and even totally preventing their
deleterious effects. This will be curative medicine of a very classical type
even if highly sophisticated.
The second possibility could be, a direct correction of the bad gene.
For instance a kind of "Magic Bullet" (a modified virus may be) could knock out
the wrong genetic information and replace it by a correct segment of DNA.
Although still very remote, this prospect is maybe not as far fetched as it
could seem today.
These two procedures can be clearly envisaged for congenital
abnormalities due to one mistake. But what about chromosomal errors where many
genes (hundreds, thousands) are in fault or in excess ? The example of Down
Syndrome to which I am particularly devoted will allow a short discussion of
the state of affairs.
In this type of mental retardation affected children carry three
chromosomes 21 instead of two normally. This trisomy 21 provokes a kind of
"overdose" of genetic information.
The situation is roughly comparable to a car with a four cylinder
engine mounted by mistake with fire spark plugs ! Sure enough the motor would
not run smoothly. A good car repairman, instead of throwing it away, (as an abo
tionist would do), would delicately disconnect the extra spark plug and thus
put the function back to normal.
We do not know yet how to unplug an extra chromosome, but nature does.
She unplugs the extra X chromosomes when necessary. Maybe some day we will
learn how to do it and apply the trick to the extra chromosome 21, responsible
for the trisomy, the cause of Down's syndrome. Pending this "tour de force",
yet to be invented, we can continue deciphering the genetic content of this
chromosome. Already eight genes and multiple unnamed protein spots and scores
of anonymous DNA segments are known. It is reasonable to suppose that in less
than 10 years, the whole DNA of this chromosome will be unraveled. In the mean
time, we can try to understand why and how the excess of the genes impair the
functionning of nerves cells and prevent the full development of intellectual
power. To keep the analogy with automobiles, we can look for some regulation of
the "carburation" of the motor, so to speak.
It is already established that trisomic 21 children are more sensitive
than normals to methotrexate (16). This anti-cancer drug interrupts the
transport system of monocarbons, the small building blocks of important
molecular edifices in the brain. This sensitivity can be demonstrated (17) in
blood cells cultivated in vitro, and numerous other modifications of the
culture medium are now feasible (18).
As curious as it could look, in vitro experimentation on cultivated
cells, taken from a few drop of blood can allow a fine analysis of the
genetical and biochemical troubles which provoke mental retardation or even
psychiatric disorders. The mental retardation linked to the fragile-X
condition, or to hypothyroïdy are other examples of this type of
investigations (19)(20).
Without going too deep in technical matters it can be predicted that
various psychiatric syndromes (autism, Alzheimer-like deterioration) will be
soon be studied experimentally in vitro, thank to these new procedures.
That is not to say that the destiny of these cheerful children will
soon be allieviated although some medication trials are already attempted with
interesting results (21)(22)(23)(24).
On the contrary, it means that important discoveries are just
beginning and that respect for human nature does not impair research but
stimulates it. The promoters of selective abortion, or of exploitation of human
embryos were mistaken offering us this cruel dilemma : either you take part in
this search and destroy mission and you accept the massacre of the innocents,
or you refuse to help the families affected by incurable children and you wash
your hands of their sorrow. No, medicine is not forced to choose between
playing Herod or Pontius Pilate. It has to fight against the disease, not
against the patient.
Nevertheless, in name of the technical progress, especially appointed
"ethical" committees will possibly continue to try to blurr the moral judgment.
But their contradictory oracles will never fully exorcize the sorrow, for a
decisive reason : Technology is cumulative, wisdom is not.
When man himself is at stake the utmost wisdom is a moral principle,
very simple and clear : "What you have done to the smallest of mine you have
done it into Me".
If doctors always remember this word, the most sophisticated technique
will remain the honest servant of rehabilitation medicine ; but if they forget
it, then a denatured biology could never be rehabilitated.
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References
(1) Smithells R. W., Nevin N.C., Seller M. J., Sheppard S., Harris R.,
Read A., Fielding D.W., Walker S., Schorah C.J., Wild J. Further experience of
vitamin supplementation for prevention of neural tube defect recurrences.
Lancet i, 1983, 1027-1031.
(2) Rosenblatt D.S., Cooper B.A., Scmutz S.N., Zaleski W.A., Casezy R.E.
Prenatal vitamin B12 therapy of a foetus with methycobalamin deficiency
(Cobalamin E Disease). Lancet i, 1985, 1127-1129.
(3) Berg D., Baumgartner M., Doring K. Selective abortion of a twin with
trisomy 21 via sectio parva in 23 pregnancy week and subsequent spontaneous
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563-565.
(4) Kanhai H.H.H., Van Rissel E.J.C., Meerman R.J., Gravenhorst J.
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(5) Walgate R. French influence in Britain. Nature 1985, 313, pp.
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(6) Editorial, Nature, An appeal to embryologist. Nature 1985, 314, pp.
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(7) Dickman S. Embryo research ban causes ructions in West Germany.
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(8) Editorial. Criminalizing research. Nature 1988, 333, pp. 787.
(9) Cochran K.W.M. German angle. Nature 1988, 334, pp. 560.
(10) Beaudet et coll. Linkage of cystic fibrosis to two tightly linked
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