Newly discovered letter: why Muller failed to cite the negative mouse mutation findings of Snell, preserving his chances to receive the Nobel Prize.

A recently acquired letter between Hermann Muller and his wife (March 21, 1933) reveals that Muller had learned that he had been nominated for the Nobel Prize in 1932 with about 1/3 of the total votes being supportive. Muller was hopeful that over time sufficient votes would lead to receiving the award. The knowledge of Muller on this matter and its timing provide a likely explanation why Muller never cited the negative mouse mutation findings of George Snell, performed under Muller's direction during that time period. This action of Muller, along with the failure of Snell to promote his discovery, greatly reduced the chances that those findings would complicate his attempt to garner support for his LNT single-hit model and its application to hereditary and cancer risk assessment. It also helped Muller achieve the Nobel Prize, allowing him the necessary international visibility to promote his ideologically driven ionizing radiation-related LNT-based paradigm.

First report of X-ray induced somatic mutation by Muller's department chair fails to support Muller's linearity hypothesis.

This paper reevaluates the first report of X-ray-induced somatic gene mutations. It was undertaken by John Patterson, Department Chair of Hermann Muller, using the same biological model, methods and equipment of Muller. Patterson reported X-ray induced mutation frequencies for X-chromosome-linked (sex-linked) recessive gene mutations in somatic cells of Drosophila melanogaster that resulted in color changes in the ommatidia of the eyes. Results were based on color changes detected in both male and female offspring irradiated while in egg, larval or pupal stages and for unirradiated controls. Patterson claimed that the observed dose response displayed linearity, with a clear implication that the linear response extended to background exposure levels of unirradiated controls. This reanalysis disputes Patterson's interpretation, showing that the dose response in the low-dose zone strongly supported a threshold model. The doses in the experiment, which were not clearly presented, were so high that it would preclude the assumption that the experiment provided any information of relevance to radiation exposures of humans at low doses, or even at high doses delivered at low-dose rates. Induced phenotypical changes that occurred at the higher doses, especially in female offspring, overwhelmingly resulted from X-ray-induced chromosome breaks instead of point mutations as initially expected by Patterson. The Patterson findings and linearity interpretations were an important contributory factor in the acceptance of the linear non-threshold (LNT) model during the formative time of concept consolidation. It is rather shocking now to see that the actual data provided no support for the LNT model.

The scientific nature of the linear no-threshold (LNT) model used in the system of radiological protection.

During the first half of the 20th century, it was commonly assumed that radiation-induced health effects occur only when the dose exceeds a certain threshold. This idea was discarded for stochastic effects when more knowledge was gained about the mechanisms of radiation-induced cancer. Currently, a key tenet of the international system of radiological protection is the linear no-threshold (LNT) model where the risk of radiation-induced cancer is believed to be directly proportional to the dose received, even at dose levels where the effects cannot be proven directly. The validity of the LNT approach has been questioned on the basis of a claim that only conclusions that can be verified experimentally or epidemiologically are scientific and LNT should, thus, be discarded because the system of radiological protection must be based on solid science. The aim of this publication is to demonstrate that the LNT concept can be tested in principle and fulfils the criteria of a scientific hypothesis. The fact that the system of radiological protection is also based on ethics does not render it unscientific either. One of the fundamental ethical concepts underlying the LNT model is the precautionary principle. We explain why it is the best approach, based on science and ethics (as well as practical experience), in situations of prevailing uncertainty.

Hormesis: Transforming disciplines that rely on the dose response.

This article tells the story of hormesis from its conceptual and experimental origins, its dismissal by the scientific and medical communities in the first half of the 20th century, and its rediscovery over the past several decades to be a fundamental evolutionary adaptive strategy. The upregulation of hormetic adaptive mechanisms has the capacity to decelerate the onset and reduce the severity of a broad spectrum of common age-related health, behavioral, and performance decrements and debilitating diseases, thereby significantly enhancing the human health span. Incorporation of hormetic-based lifestyle options within the human population would have profoundly positive impacts on the public health, significantly reducing health care costs.

Cover up and cancer risk assessment: Prominent US scientists suppressed evidence to promote adoption of LNT.

This paper reports that William Russell, Oak Ridge National Laboratory (ORNL), conducted a large-scale lifetime study from 1956 to 1959 showing that exposure of young adult male mice to a large dose of acute X-rays had no treatment effects on male and female offspring concerning longevity or the frequency, severity, or age distribution of neoplasms and other diseases. Despite the scientific, societal and crucial timing significance of the study, Russell did not publish the findings for almost 35 years, nor did he inform governmental advisory committees, thereby significantly biasing decisions made during this period which supported the adoption of LNT for risk assessment. Of further significance, Arthur Upton, an ORNL colleague of Russell during this study and later Director of the US National Cancer Institute (NCI), was also fully knowledgeable of this study, its findings and its negative impact on the acceptance of LNT. Upton later worked along with Russell to publish these data (i.e., Cosgrove et al., 1993) to dispute the case-specific claim that children developed cancer because of the radiation exposure of their fathers as workers at the Sellafield nuclear plant. Thus, while Russell's data were available, but were not used to challenge the key radiation and leukemia paper of Edward B. Lewis, (1957) when LNT was being adopted by regulatory agencies, they were used in a major trial in the United Kingdom (UK) for the client (i.e., British Nuclear Fuels Plc) that hired Upton. While the duplicity of Russell's and Upton's actions is striking, the key finding of the present paper is that Russell and Upton intentionally orchestrated and sustained an LNT cover up during the key period of LNT adoption by regulatory agencies, thereby showing an overwhelming bias to enhance the adoption of LNT.

LNT and cancer risk assessment: Its flawed foundations part 2: How unsound LNT science became accepted.

This paper argues that Edward B. Lewis served as a type of independent academic radiation LNT-cancer risk assessment-stalking horse for the BEAR Genetics Panel, a task for which he had no expertise or experience (e.g. radiation, leukemia, epidemiology and statistical modelling). His efforts produced an insufficiently documented, strongly biased, and high-profile paper in Science (May 17, 1957), whose principal conclusions had not been proven, he asserted privately, in writing. This inconclusive perspective was well camouflaged in the published paper by means of sophisticated wordsmithing. At the time his academic department head George Beadle came to chair the BEAR Genetics Panel in the summer of 1956, the Beadle-inspired-Lewis LNT activity acquired an urgency when a study of 70,000 offspring from survivors of the A-bombs failed to show genetic damage after a decade of careful study, undercutting Panel recommendations. With Beadle's guidance, the Lewis effort redirected the Panel's focus from the atomic bomb genetic damage study, which had acrimoniously disrupted Panel relationships and priorities, to more immediate disciplinary/professional opportunities with concerns about fallout, leukemia risks and a new cancer causation role for mutation. The serious limitations of the Lewis paper affected neither its publication in Science nor its receiving an editorial endorsement, possibly due to influence by powerful Panel members, such as Bentley Glass, one of only six senior editors for Science. The Science publication restored, even though improperly, the scientific and moral initiatives of the Panel and led directly to multiple high level LNT recommendations for cancer risk assessment based on the Precautionary Principle, which Lewis asserted, and which remains in place today in essentially all countries. The present paper explores how such a scientific long-shot and quasi-stalking horse, who was unsupported by BEAR Panel members during the withering criticism prompted by his Science article, nevertheless endured in the pursuit of his LNT goal, becoming strikingly successful in achieving a global cancer risk assessment revolution which remains in place.

LNT and cancer risk assessment: Its flawed foundations part 1: Radiation and leukemia: Where LNT began.

This paper evaluates the scientific basis for the adoption of the linear non-threshold (LNT) dose response model for radiation-induced leukemia. This LNT risk assessment application for leukemia is significant because it: (1) was generalized for all tumor types induced by ionizing radiation and chemical carcinogens at relatively high doses and; (2) it was based on the mechanistic assumption of low dose linearity for somatic cell mutations as determined from responses in mature spermatozoa of fruit flies. A serious problem with the latter assumption is that those spermatozoa lack DNA repair. The acceptance of the LNT dose response model for cancer risk assessment was based on the convergence of recommendations of the BEAR I Genetics Panel (1956a) for reproductive cell gene mutations and those of Lewis (1957a) for somatic cell mutation and its capacity to explain apparent and/or predicted linear dose responses of ionizing radiation-induced leukemia in multiple and diverse epidemiological investigations. Use of that model and related dose response beliefs achieved rapid, widespread and enduring acceptance in the scientific and regulatory communities. They provide the key historical foundation for the sustained LNT-based policy for cancer risk assessment to the present. While previous papers in this series have challenged key scientific assessments and ethical foundations of the BEAR I Genetics Panel, the present paper provides evidence that Lewis: 1) incorrectly interpreted the fundamental scientific studies used to support the LNT conclusion even though such studies show consistent hormetic-J-shaped dose response relationships for leukemia in Hiroshima and Nagasaki survivors; and, 2) demonstrated widespread bias in support of an LNT conclusion and related policies, which kept him from making an objective and fair assessment. The LNT recommendation appears to have been uncritically accepted and integrated into scientific and regulatory practice in large part because it inappropriately appealed to existing authority and it garnered the support of those who were willing to risk greatly exaggerating the public's fears of environmentally-induced disease, such as enhanced risk of leukemia, with the goal of stopping the atmospheric testing of atomic bombs. Adoption of the LNT recommendation demonstrated extensive penetration of ideological influence affecting governmental, scientific and regulatory evaluation at the highest levels in the United States. This paper demonstrates that the scientific foundations for cancer risk assessment were inappropriately and inaccurately assessed, unethically adopted and require significant historical, scientific and regulatory remediation.

Ethical failings: The problematic history of cancer risk assessment.

This paper demonstrates that unethical conduct by the US National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Genetics Panel led to their recommendation of the Linear Non-Threshold (LNT) Model for radiation risk assessment and its subsequent adoption by the US and the world community. The analysis, which is based largely on preserved communications of the US NAS Genetics Panel members, reveals that Panel members and their administrative leadership at the NAS displayed an integrated series of unethical actions designed to ensure, (1) the acceptance of the LNT and (2) funding to radiation geneticist panel members and professional colleagues. These findings are significant because major public policies in open democracies, such as cancer risk assessment and other issues impacted by public fears of radiation or chemical exposures, require ethical foundations. Recognition of these ethical failures of the BEAR I Genetics Panel should require a high level administrative, legislative and scientific reassessment of the scientific foundations of cancer risk assessment, with the likely result necessitating revision of current policies and practices. The BEAR I Genetics Panel, 1956 Science journal publication should immediately be retracted because it contains deliberate misrepresentations of the scientific record that were designed to manipulate scientific and public opinion on radiation risk assessment in a dishonest manner.

ALARA in practice-4 decades of radiological protection at Goesgen NPP.

This paper provides an overview of results achieved through a whole set of ALARA investigations at the Goesgen Nuclear Power Plant. Doses to workers, the public and the environment have significantly dropped in recent years. Even the doses to the most exposed workers at the plant are not bigger than doses from natural background radiation. Recent reviews of epidemiological data call attention to the importance of recognising that the risk of cancer at low doses is small and might contribute only a very small, non-detectable fraction to an individual's overall risk. Based on the global cultural change on how society is facing any kind of risk, the initial ALARA philosophy is moving more and more to a continuing expectation that optimisation is equivalent to reduction. This philosophy change is even more pronounced in the light of the ongoing discussions about the effects of low dose radiation. Multiple conservatisms in dose models and dose calculations will lead to an imbalance between radiation risks and benefits. Overweighting radiation risks from low doses causes anxiety among the public and unnecessary economic burden to nuclear facilities. In light of pressing global issues (i.e. climate change), a discussion about the meaning of the 'R' in ALARA is recommended.

Reflections on low-dose radiation, the misconceptions, reality and moving forward.

Low dose radiation has been widely accepted by the radiation protection community as presenting a very low risk to human health, if any. Over-conservatism in optimisation principles and regulations have resulted in a disproportionate fear of radiation amongst the general public and government authorities alike, overlooking the great benefits nuclear science and techniques have brought to society as a whole. As such, the World Nuclear Association advocates for a recontextualisation of the radiation hazards with regards to low dose radiation, and a greater awareness as to the absence of any discernible effects associated with it.

The Muller-Neel dispute and the fate of cancer risk assessment.

The National Academy of Sciences (NAS) Atomic Bomb Casualty Commission (ABCC) human genetic study (i.e., The Neel and Schull, 1956a report) showed an absence of genetic damage in offspring of atomic bomb survivors in support of a threshold model, but was not considered for evaluation by the NAS Biological Effects of Atomic Radiation (BEAR) I Genetics Panel. The study therefore could not impact the Panel's decision to recommend the linear non-threshold (LNT) dose-response model for risk assessment. Summaries and transcripts of the Panel meetings failed to reveal an evaluation of this study, despite its human relevance and ready availability, relying instead on data from Drosophila and mice. This paper explores correspondence among and between BEAR Genetics Panel members, including James Néel, the study director, and other contemporaries to assess why the Panel failed to use these data and how the decision to recommend the LNT model affected future cancer risk assessment policies and practices. This failure of the Genetics Panel was due to: (1) a strongly unified belief in the LNT model among panel members and their refusal to acknowledge that a low dose of radiation could exhibit a threshold, a conclusion that the Néel/Schull atomicbomb study could support, and (2) an excessive degree of self-interest among panel members who experimented with animal models, such as Hermann J. Muller, and feared that human genetic studies would expose the limitations of extrapolating from animal (especially Drosophila) to human responses and would strongly shift research investments/academic grants from animal to human studies. Thus, the failure to consider the Néel/Schull atomic bomb study served both the purposes of preserving the LNT policy goal and ensuring the continued dominance of Muller and his similarly research-oriented colleagues.

One-Decade-Spanning transgenerational effects of historic radiation dose in wild populations of bank voles exposed to radioactive contamination following the chernobyl nuclear disaster.

The concept of historic radiation doses associated with accidental radioactive releases and their role in leading to radiation-induced non-targeted effects on affected wild animals are currently being evaluated. Previous research studying Fukushima butterfly, Chernobyl bird and fruit fly populations shows that the effects are transgenerational, underlined by the principles of genomic instability, and varied from one species to another. To further expand on the responses of and their sensitivity in different taxonomically distinct groups, the present study sought to reconstruct historic radiation doses and delineate their effects on bank voles (Clethrionomys glareolus) found within a 400-km radius of the Chernobyl Nuclear Power Plant meltdown site. Historic dose reconstruction from the whole-body dose rates for the bank vole samples for their parental generation at the time of radioactive release was performed. Relationships between the historic doses and cytogenetic aberrations and embryonic lethality were examined via graphical presentations. Results suggest that genomic instability develops at the historic dose range of 20-51 mGy while a radioadaptive response develops at the historic dose range of 51-356 mGy. The Linear No-Threshold (LNT) relationship was absent at historic doses of lower than 356 mGy at all generations. However, LNT was apparent when the very high historic dose of 10.28 Gy in one sampling year was factored into the dose response curve for the bank vole generation 21-22. It is worth being reminded that natural mutation accumulation and other environmental stressors outside the realm of dose effects could contribute to the observed effects in a multiple-stressor environment. Nevertheless, the consistent development of genomic instability and radio-adaptive response across generations and sampling sites unearths the utmost fundamental radiobiological principle of transgenerational non-targeted effects. As a result, it calls for better attention and regulation from global governing bodies of environmental health protection.

Radio-biologically motivated modeling of radiation risks of mortality from ischemic heart diseases in the Canadian fluoroscopy cohort study.

Recent analyses of the Canadian fluoroscopy cohort study reported significantly increased radiation risks of mortality from ischemic heart diseases (IHD) with a linear dose-response adjusted for dose fractionation. This cohort includes 63,707 tuberculosis patients from Canada who were exposed to low-to-moderate dose fractionated X-rays in 1930s-1950s and were followed-up for death from non-cancer causes during 1950-1987. In the current analysis, we scrutinized the assumption of linearity by analyzing a series of radio-biologically motivated nonlinear dose-response models to get a better understanding of the impact of radiation damage on IHD. The models were weighted according to their quality of fit and were then mathematically superposed applying the multi-model inference (MMI) technique. Our results indicated an essentially linear dose-response relationship for IHD mortality at low and medium doses and a supra-linear relationship at higher doses (> 1.5 Gy). At 5 Gy, the estimated radiation risks were fivefold higher compared to the linear no-threshold (LNT) model. This is the largest study of patients exposed to fractionated low-to-moderate doses of radiation. Our analyses confirm previously reported significantly increased radiation risks of IHD from doses similar to those from diagnostic radiation procedures.

Glycan Binding Specificity and Mechanism of Human and Porcine P[6]/P[19] Rotavirus VP8*s.

Rotaviruses (RVs), which cause severe gastroenteritis in infants and children, recognize glycan ligands in a genotype-dependent manner via the distal VP8* head of the spike protein VP4. However, the glycan binding mechanisms remain elusive for the P[II] genogroup RVs, including the widely prevalent human RVs (P[8], P[4], and P[6]) and a rare P[19] RV. In this study, we characterized the glycan binding specificities of human and porcine P[6]/P[19] RV VP8*s and found that the P[II] genogroup RV VP8*s could commonly interact with mucin core 2, which may play an important role in RV evolution and cross-species transmission. We determined the first P[6] VP8* structure, as well as the complex structures of human P[19] VP8*, with core 2 and lacto-N-tetraose (LNT). A glycan binding site was identified in human P[19] VP8*. Structural superimposition and sequence alignment revealed the conservation of the glycan binding site in the P[II] genogroup RV VP8*s. Our data provide significant insight into the glycan binding specificity and glycan binding mechanism of the P[II] genogroup RV VP8*s, which could help in understanding RV evolution, transmission, and epidemiology and in vaccine development.IMPORTANCE Rotaviruses (RVs), belonging to the family Reoviridae, are double-stranded RNA viruses that cause acute gastroenteritis in children and animals worldwide. Depending on the phylogeny of the VP8* sequences, P[6] and P[19] RVs are grouped into genogroup II, together with P[4] and P[8], which are widely prevalent in humans. In this study, we characterized the glycan binding specificities of human and porcine P[6]/P[19] RV VP8*s, determined the crystal structure of P[6] VP8*, and uncovered the glycan binding pattern in P[19] VP8*, revealing a conserved glycan binding site in the VP8*s of P[II] genogroup RVs by structural superimposition and sequence alignment. Our data suggested that mucin core 2 may play an important role in P[II] RV evolution and cross-species transmission. These data provide insight into the cell attachment, infection, epidemiology, and evolution of P[II] genogroup RVs, which could help in developing control and prevention strategies against RVs.

Muller's Nobel Prize data: Getting the dose wrong and its significance.

This paper evaluates the significant historical paper of Muller and Mott-Smith (1930), which successfully disputed the proposal of Olson and Lewis (1928) that background ionizing radiation is the driving mechanism of evolution. While the present analysis supports the general conclusion that background radiation is not a quantifiable factor affecting evolution, the paper reveals methodological errors and questionable conclusions in the Muller and Mott-Smith (1930) paper, which may have impacted the acceptance of the linear non-threshold (LNT) model. Most importantly, this paper reveals that in Muller's (1927) Nobel Prize research he used a treatment exposure (total dose) that was 95 million-fold greater than the average background exposure, a value far greater than the 200,000 fold reported by Muller and Mott-Smith (1930). Such a large exposure rate discrepancy may be historically important as it may have led to the over-reliance on Muller's research in support of the derivation and use of the LNT single-hit model.

Biophysical characterization and stabilization of detergent-solubilized lipoprotein N-acyl transferase from P. aeruginosa and E. coli.

Lipoproteins are important for bacterial growth and virulence and interest in them as targets for antibiotic development is growing. Lipoprotein N-acyl transferase (Lnt) catalyzes the final step in the lipoprotein posttranslational processing pathway. The mature lipoprotein can remain in the inner membrane or be trafficked to the outer membrane in the case of diderm prokaryotes. With a view to obtaining high-resolution crystal structures of membrane integral Lnt for use in drug discovery a program was undertaken to generate milligram quantities of stable, homogenous and functional protein. This involved screening across bacterial species for suitable orthologues and optimization at the level of protein expression, solubilization and stability. Combining biophysical and functional characterization, orthologous Lnt from Escherichia coli and the opportunistic human pathogen Pseudomonas aeruginosa was identified as suitable for the proposed structure determination campaign that ultimately yielded crystal structures. The rational approaches taken that eventually provided structure-quality protein are presented in this report.

The apolipoprotein N-acyl transferase Lnt is dispensable for growth in Acinetobacter species.

Directing the flow of protein traffic is a critical task faced by all cellular organisms. In Gram-negative bacteria, this traffic includes lipoproteins. Lipoproteins are synthesized as precursors in the cytoplasm and receive their acyl modifications upon export across the inner membrane. The third and final acyl chain is added by Lnt, which until recently was thought to be essential in all Gram-negatives. In this report, we show that Acinetobacter species can also tolerate a complete loss-of-function mutation in lnt. Absence of a fully functional Lnt impairs modification of lipoproteins, increases outer membrane permeability and susceptibility to antibiotics, and alters normal cellular morphology. In addition, we show that loss of lnt triggers a global transcriptional response to this added cellular stress. Taken together, our findings provide new insights on and support the growing revisions to the Gram-negative lipoprotein biogenesis paradigm.

Preclinical safety evaluation of the human-identical milk oligosaccharide lacto-N-tetraose.

Lacto-N-tetraose (LNT) is one of the most abundant oligosaccharides that are endogenously present in human breast milk. To simulate the composition of human breast milk more closely, commercial infant formula can be supplemented with human-identical milk oligosaccharides, which are manufactured structurally identical versions of their naturally occurring counterparts. As part of the safety evaluation of LNT, in vitro genotoxicity tests and a subchronic oral gavage toxicity study (in neonatal Sprague-Dawley rats) were conducted. In the subchronic study, LNT was administered at dose levels of 0, 1,000, 2500 or 4000 mg/kg body weight (bw)/day, once daily for at least 90 days, followed by a 4-week treatment-free period. An identically comprised reference control group received fructooligosaccharides powder (a non-digestible oligosaccharide used in infant formula) at 4000 mg/kg bw/day, to allow for direct comparison against the high-dose LNT group. LNT was non-genotoxic in the in vitro tests. There were no compound-related adverse effects in the 90-day study; therefore, 4000 mg/kg bw/day (the highest feasible dose) was established as the no-observed-adverse-effect-level. These results support the safe use of LNT in infant formula and as a food ingredient, at levels not exceeding those found naturally in human breast milk.

The threshold vs LNT showdown: Dose rate findings exposed flaws in the LNT model part 2. How a mistake led BEIR I to adopt LNT.

This paper reveals that nearly 25 years after the National Academy of Sciences (NAS), Biological Effects of Ionizing Radiation (BEIR) I Committee (1972) used Russell's dose-rate data to support the adoption of the linear-no-threshold (LNT) dose response model for genetic and cancer risk assessment, Russell acknowledged a significant under-reporting of the mutation rate of the historical control group. This error, which was unknown to BEIR I, had profound implications, leading it to incorrectly adopt the LNT model, which was a decision that profoundly changed the course of risk assessment for radiation and chemicals to the present.

The threshold vs LNT showdown: Dose rate findings exposed flaws in the LNT model part 1. The Russell-Muller debate.

This paper assesses the discovery of the dose-rate effect in radiation genetics and how it challenged fundamental tenets of the linear non-threshold (LNT) dose response model, including the assumptions that all mutational damage is cumulative and irreversible and that the dose-response is linear at low doses. Newly uncovered historical information also describes how a key 1964 report by the International Commission for Radiological Protection (ICRP) addressed the effects of dose rate in the assessment of genetic risk. This unique story involves assessments by two leading radiation geneticists, Hermann J. Muller and William L. Russell, who independently argued that the report's Genetic Summary Section on dose rate was incorrect while simultaneously offering vastly different views as to what the report's summary should have contained. This paper reveals occurrences of scientific disagreements, how conflicts were resolved, which view(s) prevailed and why. During this process the Nobel Laureate, Muller, provided incorrect information to the ICRP in what appears to have been an attempt to manipulate the decision-making process and to prevent the dose-rate concept from being adopted into risk assessment practices.