AW: AW: [ RadSafe ] cancer is the result of defective tissue/immunecontrol

[John Jacobus]

Rainer,
Thanks for the reply.  I thought that the theory for
the loss of bone cells and mass due to microgravity
and the lack of stress on the skeleton.  I was under
the impression that the problem with immunocompetence
was also due a lack of "stresses," e.g., a lack of
antigens and germs.  

--- Rainer.Facius at dlr.de wrote:

> "By the way, why do you think microgravity causes
> immuncompetency? Certainly not the lack of
> radiation. How about the decalcification?"
> 
> Dear John:
> 
> The primary cause of impaired immunocompetence under
> prolonged weightlessness is supposed to be a
> systemic response to internal fluid shifts and
> associated (after an adaptation period persistent)
> changes of the humoral status, salt balance, ... .
> Mechanisms are still mostly hypothetical, e.g.
> regarding kidney involvement, as are putative
> receptors and signal chains already on a cellular
> level. Bone metabolism to my knowledge has not yet
> been causally associated with reduced
> immunocompetence.
> 
> Kind regards, Rainer
> 
> 
> 
> 
> ________________________________
> 
> Von: John Jacobus [mailto:crispy_bird at yahoo.com]
> Gesendet: Fr 30.06.2006 20:10
> An: Facius, Rainer; radsafe at radlab.nl
> Betreff: Re: AW: [ RadSafe ] cancer is the result of
> defective tissue/immunecontrol
> 
> 
> 
> Rainer,
> I do know what I should reconsider.  That the immune
> system does not recognize the tumor as foreign? 
> 
> It is apparent that tumors and cancers are
> conditions
> of old age.  One idea is that the cells that make up
> the tumor change do not atrophy as they should, so
> the
> immune system still recognizes the tumors as self.
> The alternative is the immune system is weakened and
> cannot attack the tumor.  Of course, in a young
> person, the immune system should be "strong," but
> still the tumor develops.  Interesting question,
> don't
> you think?  COuld it be that there may be more than
> one mechanisms? 
> 
> I suggest you ask your friend what he means.  I
> would
> remind you that the Kim paper really only considers
> one type on tumor in a non-human model.  It may not
> represent the results in other murine tumors, or in
> humans.  Biology is not like physics.  One equation
> may not fit all cases. 
> 
> By the way, why do you think microgravity causes
> immuncompetency?  Certainly not the lack of
> radiation.
> How about the decalcification?
> 
> --- Rainer.Facius at dlr.de wrote:
> 
> > John:
> >
> > This very Thursday I was discussing with the head
> of
> > our Institute - a medical Professor holding also
> the
> > chair of Aerospace Medicine of our very
> prestigious
> > University RWTH Aachen - the curriculum for a new
> > Course on Space Medicine in our institute.
> >
> > Among the topics in physiology, the altered
> > immunocompetence in microgravity was assigned to
> an
> > extra lecture. Without thinking about my post I
> drew
> > his attention to the fact that - according to
> > recently emerging empirical evidence - such
> > alterations might well affect seriously our space
> > radiation cancer risk estimates, e.g. for planned
> > missions to Mars if indeed - as I surmised -
> > tumourigenesis were significantly controlled
> (also)
> > by the immune system. In response he looked at me
> > with an expression of astonishment and (in
> essence)
> > said:
> >
> > "Well, this is really an old hat!"
> >
> > In other words, for him - the Professor of
> Medicine
> > - these exciting observations by Kim et al.
> provide
> > just an animal-experimental corroboration of
> matters
> > of fact which for man are already established.
> >
> > I in turn was surprised seeing him consider this
> as
> > a matter of course and was not prepared to argue
> > against it. I certainly will pick up this topic on
> > the next occasion with him and you as well might
> > wish to reconsider it.
> >
> > Kind regards, Rainer
> >
> > Dr. Rainer Facius
> > German Aerospace Center
> > Institute of Aerospace Medicine
> > Linder Hoehe
> > 51147 Koeln
> > GERMANY
> > Voice: +49 2203 601 3147 or 3150
> > FAX:   +49 2203 61970
> >
> > -----Ursprüngliche Nachricht-----
> > Von: radsafe-bounces at radlab.nl
> > [mailto:radsafe-bounces at radlab.nl] Im Auftrag von
> > John Jacobus
> > Gesendet: Donnerstag, 29. Juni 2006 23:20
> > An: Facius, Rainer; radsafe at radlab.nl
> > Betreff: Re: [ RadSafe ] cancer is the result of
> > defective tissue/immunecontrol
> >
> > Rainer,
> > As you note, at least in murine gastrointestinal
> > cancer (sic) this is true.  However, I do not
> think
> > you can say this about other cancers.  I guess you
> > could, but do you think all cancers are due to
> > defective tissue/immune control?  It is a question
> > of recognition of "self," e.g., cancers are
> > recognized as normal tissues, which they are to
> the
> > immune system.
> >
> >
> 
> +++++++++++++++++++
> "You get a lot more authority when the workforce
> doesn't think it's amateur hour on the top floor."
> GEN. MICHAEL V. HAYDEN, President Bush's nominee for
> C.I.A. director.
> 
> -- John
> John Jacobus, MS
> Certified Health Physicist
> e-mail:  crispy_bird at yahoo.com
> 
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> 


+++++++++++++++++++
"You get a lot more authority when the workforce doesn't think it's amateur hour on the top floor."
GEN. MICHAEL V. HAYDEN, President Bush's nominee for C.I.A. director.

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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