Re: Abscopal effects on critical organs

[Mike Grissom <mikeg@SLAC.Stanford.EDU>]

Dave and any others who may be interested,

You may be able to find details on these kinds
of effects by going to the Armed Forces Radiobiology
Research Institute's Web site at URL:

	http://www.afrri.usuhs.mil/

Studies done there (and elsewhere) suggest that
histamine release in acute exposures (most of the
modeling related, be aware, to external field
exposures - but some limited exposure studies were
done controlling which organs were irradiated) at
non-critical organs can have sufficient effect to
potentiate lethality (whole animal effects such
as excessive blood pressure depression), and/or
short-term incapacitation. Of course, the time
parameter for total dose accumulation may not
allow for direct extrapolation of these effects to
the very large immersion/uptake doses that would
be needed to lead (ultimately) to lethality.

Obviously, the deterministic effects are what
matter in your study. Other indirect effects, such
as free radical formation, may be more important
at the cellular level.

S.,

MikeG.


At 01:44 PM 10/15/98 -0500, you wrote:
>I've been working on a project that involves predicting the quantities of
>airborne radionuclides that it would take to produce an acute lethality
>within 60 days.  This involves estimating how much immersion and inhalation
>it would take to produce a lethal dose to the bone marrow, small intestine,
>and lungs.  The calculations have included cross talk, i.e., transport of
>photons from noncritical organs to critical organs.  A reviewer insists
>that this approach is flawed because it doesn't take into account indirect
>effects.  Direct effects on a noncritical organ will influence the lethal
>dose on the critical organs.  I have been unable to find any data to
>substantiate or refute this abscopal effect on lethal doses.  Can anyone
>shed some light on this question, preferably with citations in available.  
>
>Thanks,
>David Abbott
>Lawrence Livermore National Laboratory


************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html