Moving beyond a descriptive aquatic toxicology: the value of biological process and trait information

In order to improve the ability to link chemical exposure to toxicological and ecological effects, aquatic toxicology will have to move from observing what chemical concentrations induce adverse effects to more explanatory approaches, that are concepts which build on knowledge of biological processes and pathways leading from exposure to adverse effects, as well as on knowledge on stressor vulnerability as given by the genetic, physiological and ecological (e.g., life history) traits of biota. Developing aquatic toxicology in this direction faces a number of challenges, including (i) taking into account species differences in toxicant responses on the basis of the evolutionarily developed diversity of phenotypic vulnerability to environmental stressors, (ii) utilizing diversified biological response profiles to serve as biological read across for prioritizing chemicals, categorizing them according to modes of action, and for guiding targeted toxicity evaluation; (iii) prediction of ecological consequences of toxic exposure from knowledge of how biological processes and phenotypic traits lead to effect propagation across the levels of biological hierarchy; and (iv) the search for concepts to assess the cumulative impact of multiple stressors. An underlying theme in these challenges is that, in addition to the question of what the chemical does to the biological receptor, we should give increasing emphasis to the question how the biological receptor handles the chemicals, i.e., through which pathways the initial chemical-biological interaction extends to the adverse effects, how this extension is modulated by adaptive or compensatory processes as well as by phenotypic traits of the biological receptor.

Occupational, personal and psychosocial resources for preventing persistent low back pain

The aim of this prospective cohort study was to identify modifiable protective factors of the progression of acute/subacute low back pain (LBP) to the persistent state at an early stage to reduce the socioeconomic burden of persistent LBP. Patients attending a health practitioner for acute/subacute LBP were assessed at baseline addressing occupational, personal and psychosocial factors, and followed up over 12 weeks. Pearson correlations were calculated between these baseline factors and the presence of nonpersistent LBP at 12-week follow-up. For those factors found to be significant, multivariate logistic regression analyses were performed. The final 3-predictor model included job satisfaction, mental health and social support. The accuracy of the model was 72%, with 81% of nonpersistent and 60% of persistent LBP patients correctly identified. Further research is necessary to confirm the role of different types of social support regarding their prognostic influence on the development of persistent LBP.

Prognostic occupational factors for persistent low back pain in primary care

To reduce the socio-economic burden of persistent low back pain (LBP), factors influencing the progression of acute/subacute LBP to the persistent state must be identified at an early stage.

NADPH-cytochrome P450 oxidoreductase: roles in physiology, pharmacology, and toxicology

This is a report on a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics and held at the Experimental Biology 2012 meeting in San Diego, California, on April 25, 2012. The symposium speakers summarized and critically evaluated our current understanding of the physiologic, pharmacological, and toxicological roles of NADPH-cytochrome P450 oxidoreductase (POR), a flavoprotein involved in electron transfer to microsomal cytochromes P450 (P450), cytochrome b(5), squalene mono-oxygenase, and heme oxygenase. Considerable insight has been derived from the development and characterization of mouse models with conditional Por deletion in particular tissues or partial suppression of POR expression in all tissues. Additional mouse models with global or conditional hepatic deletion of cytochrome b(5) are helping to clarify the P450 isoform- and substrate-specific influences of cytochrome b(5) on P450 electron transfer and catalytic function. This symposium also considered studies using siRNA to suppress POR expression in a hepatoma cell-culture model to explore the basis of the hepatic lipidosis phenotype observed in mice with conditional deletion of Por in liver. The symposium concluded with a strong translational perspective, relating the basic science of human POR structure and function to the impacts of POR genetic variation on human drug and steroid metabolism.

Aspiration toxicology of hydrocarbons and lamp oils studied by in vitro technology

Medical literature regularly reports on accidental poisoning in children after aspiration of combustibles such as lamp oils which usually contain hydrocarbons or rape methyl esters (RMEs). We aimed to analyze the toxic potential of alkanes and different combustible classes in vitro with regard to biologic responses and mechanisms mediating toxicity. Two different in vitro models were used, i.e. (i) a captive bubble surfactometer (CBS) to assess direct influence of combustibles on biophysical properties of surfactant film and (ii) cell cultures (BEAS-2B and R3/1 cells, primary macrophages, re-differentiated epithelia) closely mimicking the inner lung surface. Biological endpoints included cell viability, cytotoxicity and inflammatory mediator release. CBS measurements demonstrate that combustibles affect film dynamics, i.e. the surface tension/area characteristics during compression and expansion, in a dose and molecular chain length dependent manner. Cell culture results confirm the dose dependent toxicity. Generally, cytotoxicity and cytokine release are higher in short-chained alkanes and hydrocarbon-based combustibles than in long-chained substances, e.g. highest inducible cytotoxicity in BEAS-2B was for hexane 84.6%, decane 74% and hexadecane 30.8%. Effects of RME-based combustibles differed between the cell models. Our results confirm data from animal experiments and give new insights into the mechanisms underlying the adverse health effects observed.

Occupational maxillofacial fractures: a 3-year survey in central Switzerland

PURPOSE: The aim of this study was to determine occupational facial fractures in central Switzerland. Concomitant injuries were also studied. MATERIALS AND METHODS: The Department of Cranio-Maxillofacial Surgery at the University Hospital in Berne provides a 24-hour maxillofacial trauma service for its population (1.6 million). The present study was comprised of 42 patients (8.4% of treated maxillofacial injuries) with occupational maxillofacial fractures registered at this unit between 2000 and 2002. Information on the topic of occupation, the cause of the accidents, and the topographic location of the fractures was analyzed. RESULTS: The mean age of the patients was 44.4 years, with a male to female ratio of 41:1. Sixty-nine percent of the injuries occurred in farm and forestry workers and in construction laborers during the summertime (33%). Workers in these occupations carried a 127-fold (farm and forestry workers) and a 44-fold (construction laborers) higher risk of incurring maxillofacial fractures than did service and office workers. Injuries were most frequently (43%) caused by a thrown, projected, or falling object. Eighty-two percent of the fractures occurred in the midface region and at the skull base. Fifty-nine percent of the patients had concomitant injuries. In 69%, surgery was necessary, the mean duration of their hospital stay being 4.8 days. CONCLUSION: The probability of sustaining work-related maxillofacial traumata is correlated to the nature of the occupation. Farm and forestry workers are at the highest risk, most frequently injured by being struck by an object or an animal. The introduction of personalized safety measures should become obligatory in high-risk occupations.

Sustainability study of nanomaterials including societal and occupational implications

In recent years there has been a tremendous amount of research in the area of nanotechnology. History tells us that the commercialization of technologies will always be accompanied by both positive and negative effects for society and the environment. Products containing nanomaterials are already available in the market, and yet there is still not much information regarding the potential negative effects that these products may cause. The work presented in this dissertation describes a holistic approach to address different dimensions of nanotechnology sustainability. Life cycle analysis (LCA) was used to study the potential usage of polyethylene filled with nanomaterials to manufacture automobile body panels. Results showed that the nanocomposite does not provide an environmental benefit over traditional steel panels. A new methodology based on design of experiments (DOE) techniques, coupled with LCA, was implemented to investigate the impact of inventory uncertainties. Results showed that data variability does not have a significant effect on the prediction of the environmental impacts. Material profiles for input materials did have a highly significant effect on the overall impact. Energy consumption and material characterization were identified as two mainstreams where additional research is needed in order to predict the overall impact of nanomaterials more effectively. A study was undertaken to gain insights into the behavior of small particles in contact with a surface exposed to air flow to determine particle lift-off from the surface. A mapping strategy was implemented that allows for the identification of conditions for particle liftoff based on particle size and separation distance from the wall. Main results showed that particles smaller than 0:1mm will not become airborne under shear flow unless the separation distance is greater than 15 nm. Results may be used to minimize exposure to airborne materials. Societal implications that may occur in the workplace were researched. This research task explored different topics including health, ethics, and worker perception with the aim of identifying the base knowledge available in the literature. Recommendations are given for different scenarios to describe how workers and employers could minimize the unwanted effects of nanotechnology production.