[ RadSafe ] dose RATE is the decisive variable - the wheel of reincarnation of ideas

[Rainer.Facius at dlr.de]

Prof. Raabe's pointer to his publications in the early 1980ies stirred my subconciousness until it unearthed another still earlier source where radiobiological responses were treated as functions of dose-rate as the primary independent variable instead of dose, and where in the most general case response function were drawn as a function of time. I encountered this approach during the Symposia on Microdosimetry, where Pierre Delattre and his co-worker J. Delforge attempted to persuade radiobiologists to look at radiobiological experiments - actually already at their design - from the vantage point of Delattre's systems theoretical formalism (see refs. below). Unfortunately most of them apparently were overtaxed by the mathematics (though mostly only systems of linear differential equations) and - perhaps more importantly - by the required radical redesign of the conventional radiobiological experimentation they were adapted to. In addition, the stage for their proposals was unfavourable since at these Symposia - as in this decade - radiobiologists strove to understand radiobiological effects primarily in terms of the microscopic (later even the nanoscopic!) spatial distribution of initial energy deposition events in abstract sites - though when pressed they would invoke DNA as a target.

>From the second book below I copied an interesting graph displaying shapes of time-response functions predicted by his approach which cover hypersensitivity, induced radiation resistance as encountered experimentally many years later and (more interestingly) hormesis - 'predicted' 1971! by a biologically sophisticated systems-theoretical formalism. If the moderator will let this pass, you can see this predicted hormetic response in the attached PDF file.

Regards, Rainer



Pivotal references:

Pierre Delattre
Système, Structure, Fonction, Évolution - Essai d'analyse épistémologique.
Maloine-Doin, Paris 1971

Pierre Delattre
L'Évolution des Sytèmes Moléculaires: Bases théoriques - Applications à la Chimie et à la Biologie.
Maloine-Doin, Paris 1971 

Delattre P.
Sur l'interprétation des certaines aspects morphologiques des courbes de survie.
In: Proc. 5th Symp. on Microdosimetry (Booz J, Ebert H G, Smith B G R, eds.), pp 479-515
The Commission of the European Communities, EUR 5452, Luxembourg, 1976 

I also found a pointer to a slightly more recent short review of Delattre's work in http://membres.lycos.fr/mcxapc/lectures/indexlec.htm

________________________________

Von: Otto Raabe [mailto:ograabe at ucdavis.edu]
Gesendet: Sa 02.09.2006 17:34
An: Facius, Rainer; radsafe at radlab.nl
Betreff: Re: AW: [ RadSafe ] dose RATE is the decisive variable


At 02:17 AM 9/2/2006, Rainer.Facius at dlr.de wrote:


	Dear Prof. Raabe:
	Though you apparently detected the ramifications of this fundamental principle quite some time ago, this time the data pertain directly to human cancer mortality (which of course I would expect to display the same regularities). 


Human cancer is from radium is directly evaluated in:

Raabe, O.G., S.A. Book and N.J. Parks (1980) Bone cancer from radium: Canine dose response explains data for mice and humans. Science 208: 61 64.

Raabe, O.G., S.A. Book and N.J. Parks. (1983) Lifetime bone cancer dose-response relationships in beagles and people from skeletal burdens of 226Ra and 90Sr. Health Physics 44: 33 48

Raabe, O.G. (1989) Scaling of fatal cancer risks from laboratory animals to man. Health Physics 57 (suppl.1): 419-432.
 
Raabe, O.G., L.S. Rosenblatt and R.A Schlenker. (1990) Interspecies scaling of risk for radiation-induced bone cancer. International Journal of Radiation Biology 57: 1047-1061.



**********************************************
Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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