Re: RADSAFE digest 3069 ALARA/A single ionizing event

[Magnu96196@aol.com]

In a message dated 4/5/00 4:22:51 PM Eastern Daylight Time, 
radsafe@romulus.ehs.uiuc.edu writes:

<< RADSAFERS,
 Someone recently stated the following
 
 "Why ALARA?  Quite simply this:  One ionizing event can cause a single
  unrepaired double strand break, which may result in a fatal
 malignancy."
 
 If a single ionizing event is so potent, why aren't we all dead?  >>


=================================================

Hello RadSafers,

      There is a real problem with statements like this.    Why?     Well 
certainly radiation can cause DNA damages that make a cell cancerous, free 
radicals from radiation or chemical do that.     We actually have cancer 
cells form each day just due to natural processes.

     So, the more realistic process to ask is what happens that allows 
cancers cells to propagate.   Here the discussion has to get into the immune 
system defenses, which are designed to weed out the cancer cells, and if one 
reads up on it, even virus infected cells, fungus,  bacteria, etc.

    So, if one follows this reasoning----the question of cancers become more 
a question of what caused the immune system to fail.     Numerous problems 
are seen to affect the immune defenses, like interference with antibodies or 
interference with macrophages and T-cells.

  There is substance in the suggestion that folks in Denver get more 
radiation and they don't have the higher cancer rates.    There is substance 
in the resistance to radiation in the fingers in lumbs is up around 50 R, 
which that for total body is down around 5 R-----where the immune forming 
cell networks are more targeted.      

   The modern immune theory says the immune system is directly involved in 
the regulation of cancers and many cancers are viral in origin.

    So, why does not the discussion for cancer not first involve what damaged 
the immune protection?    Cancer cell formations are a natural process of 
everyday life.

    You see flight attendants and airline pilots are some of the highest 
dosed occupations around and they do get slight increases in cancers---- the 
doses are real high.    This certainly suggests a big tolerance to external 
radiation.

    So, does anyone know how the immune system governs cancer cell regulation 
and how radiation might affect the immune cells.    Do mechanisms like cell 
damage pull pollutants into lymph nodes at higher concentrations than the 
rest of the body and will these free radical components damage cell 
mitochondria for the immune cells?

Sincerely,
Jim Phelps, near the Superfund Site of Oak Ridge

Ref:
http://www.angelfire.com/pe/MitochondriaEve/
 
 Mitochondria Theory
 
 Every living creature...plants...animals...human 
 beings....bloodvamps...psivamps, and beyond...is composed of biological 
 building blocks called "cells". Cells reproduce and multiply, using DNA 
 (deoxyribonucleic acid) as a genetic bluprint that tells them what tissues, 
 organs, and organisms to create. By whatever standard of beliefe you hold, 
be 
 it creationism, evolution, or decisively "other" one has to be amazed at how 
 perfectly our cells work to support themselves, and seemingly could go on 
 forever. The focus of this theory, however, is aimed towards the 
 mitochondria. 
 
 "Every cell of the body contains many tiny organelles called mitochondria . 
 These mitochondria produce most of the energy used by the body. Cells with a 
 high metabolic rate (heart muscle cells) may contain many thousands of 
 mitochondria. Some cells may contain only dozens. 
 
 Mitochondrial energy production is a foundation for health and wellbeing. It 
 is necessary for physical strength, stamina and consciousness. Even subtle 
 deficits in mitochondrial function can cause weakness, fatigue and cognitive 
 difficulties. Chemicals which strongly interfere with mitochondrial function 
 are known to be potent poisons. During aging, mitochondrial function may 
 become compromised." 
 
 Basically, the mitochondria supply almost all of the energy to the cell 
 (90%). Without mitochondria there is no life, because, as we all well know, 
 life requires energy! 
 
 "Mitochondrial energy production is accomplished by two closely linked 
 metabolic processes. First, the citric acid cycle converts biological fuel 
 (carbohydrates and fatty acids) into ATP (adenosine triphosphate) and 
 hydrogen (in the form of NADH and FADH2)for further explanation of NADH and 
 FADH2). Second, the electron transport chain combines hydrogen with oxygen 
to 
 generate abundant ATP in a highly efficient and tightly controlled manner. 
 Mitochondrial efficiency has been reported to be close to 70%, which 
compares 
 quite favorably with internal combustion engines (about 10% efficient) or 
 hydrogen-oxygen fuel cells used in spacecraft (approximately 40% efficient). 
 The process of generating ATP with oxygen is called oxidative 
 phosphorylation. This process generates approximately ten times more ATP 
than 
 the citric acid cycle alone, and generates more ATP than any other 
 energy-producing pathway (e.g., glycolysis). Oxidative phosphorylation is 
the 
 primary energy process for all aerobic organisms." 
 
 In order for the mitochondria to survive, it requires oxygen, supplied by 
the 
 nucleus, thus forming a symbiotic relationship. The way our cells are set 
up, 
 if the amount energy processed in the cells remained abundant, we would not 
 age much past our prime due to the constant regeneration of live cells. It 
is 
 actually the inefficiency of mitochondra, called Mitochondrian Aging that 
 causes aging and eventual death. 
 
 "Mitochondrial electron transport is not perfect. Even under ideal 
 conditions, some electrons “leak” from the electron transport chain. These 
 leaking electrons interact with oxygen to produce superoxide radicals. With 
 mitochondrial dysfunction, leakage of electrons can increase significantly. 
 The close proximity of mtDNA to the flux of superoxide radicals (or hydroxyl 
 radicals), and it’s lack of protection and repair mechanisms, leads to free 
 radical-mediated mutations and deletions. Mitochondrial aging has been 
 proposed as an underlying cause of 1) free-radical stress, 2) degenerative 
 disease and 3) aging [Miguel, 1980, 1991, 1992, Shigenaga et al., 1994]. 
 
 Evidence is accumulating that mitochondrial dysfunction underlies many 
common 
 pathologies. Mitochondrial defects have been identified in Parkinson’s 
 disease, Alzheimer’s disease [Hutchin and Cortopassi, 1995], heart disease, 
 fatigue syndromes, numerous genetic conditions, and nucleoside therapy for 
 AIDS. Also, many common nutritional deficiencies can impair mitochondrial 
 efficiency. 
 
 At this time, the degree of mitochondrial involvement in age-related mental 
 decline (ARMD) and age-associated memory impairment (AAMI) is not known. A 
 significant amount of the mitochondrial DNA (mtDNA) damage seen in 
 Parkinson’s disease is also observed in age-matched controls. Such 
 observations suggest that reductions in mitochondrial efficiency and ATP 
 output may underlie many age-associated phenomena. The successful use of 
 mitochondrial support nutrients to ameliorate serious mitochondrial diseases 
 may prove to be generalizable to the subclinical complaints of normal, 
 healthy, aging humans." 
 
 For scientists of microbiology and genetics, there is a commonly believed 
 theory which states that the fundamental genetic instinct is suvival of the 
 species. According to microbiology, the nucleus and the mitochondria of the 
 cell are dependant upon one another for survival. But this wasn't always so. 
 
 "One interesting property of mitochondria is that they have their own DNA 
 (deoxyribonucleic acid), the stuff of which genes and chromosomes are made. 
 Mitochondrial DNA (mtDNA) is quite different from nuclear DNA in several 
 respects. First, it exists as a simple plasmid (a DNA loop), and in this 
 respect, it is more akin to bacterial DNA than the chromosomal DNA of higher 
 organisms. Second, mtDNA is not associated with histones. Histones are 
 positively charged “storage” proteins around which nuclear DNA is wound for 
 safekeeping (like thread on a spool). Third, most of the complex DNA repair 
 mechanisms that correct damage to nuclear DNA are missing from mitochondria. 
 All of these features have prompted some scientists to speculate that 
 mitochondria are ancient remnants of primitive symbiotic bacteria. Whether 
 this view is correct or not, the relatively unprotected and unrepaired mtDNA 
 suffers more than ten times the damage that nuclear DNA does [Miguel, 1991, 
 1992; Shigenaga et al., 1994]. This leads to mitochondrial dysfunction, 
 disruption of cellular energy production, and accelerated cellular aging 
 [Miguel, 1980]." 

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