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.

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.

Tumour suppressors in liver carcinogenesis

The circuitous cell signalling pathways of hepatocytes comprise several factors that operate to downgrade or even interrupt the transmission of a given signal. These down-regulating influences are essential to keep cell proliferation and cell survival in check and if impaired, can alter a delicate balance in favour of cell proliferation. Each signalling pathway that has been implicated in carcinogenesis is influenced by both oncogenic factors that promote tumour growth when activated as well as tumour suppressor proteins that have to be impaired to favour tumour growth. This summary of the Tumour Suppressors in Liver Carcinogenesis Symposium held at the 2007 EASL Annual Meeting discusses four pathways with pre-eminent tumour suppressor activity, each involved in hepatocarcinogenesis: p53, mTOR, beta-catenin and hedgehog.

Molecular mechanisms of alcohol-mediated carcinogenesis

Approximately 3.6% of cancers worldwide derive from chronic alcohol drinking, including those of the upper aerodigestive tract, the liver, the colorectum and the breast. Although the mechanisms for alcohol-associated carcinogenesis are not completely understood, most recent research has focused on acetaldehyde, the first and most toxic ethanol metabolite, as a cancer-causing agent. Ethanol may also stimulate carcinogenesis by inhibiting DNA methylation and by interacting with retinoid metabolism. Alcohol-related carcinogenesis may interact with other factors such as smoking, diet and comorbidities, and depends on genetic susceptibility.

Placental growth factor-1 attenuates vascular endothelial growth factor-A-dependent tumor angiogenesis during beta cell carcinogenesis

Members of the vascular endothelial growth factor (VEGF) family are critical players in angiogenesis and lymphangiogenesis. Although VEGF-A has been shown to exert fundamental functions in physiologic and pathologic angiogenesis, the exact role of the VEGF family member placental growth factor (PlGF) in tumor angiogenesis has remained controversial. To gain insight into PlGF function during tumor angiogenesis, we have generated transgenic mouse lines expressing human PlGF-1 in the beta cells of the pancreatic islets of Langerhans (Rip1PlGF-1). In single-transgenic Rip1PlGF-1 mice, intra-insular blood vessels are found highly dilated, whereas islet physiology is unaffected. Upon crossing of these mice with the Rip1Tag2 transgenic mouse model of pancreatic beta cell carcinogenesis, tumors of double-transgenic Rip1Tag2;Rip1PlGF-1 mice display reduced growth due to attenuated tumor angiogenesis. The coexpression of transgenic PlGF-1 and endogenous VEGF-A in the beta tumor cells of double-transgenic animals causes the formation of low-angiogenic hPlGF-1/mVEGF-A heterodimers at the expense of highly angiogenic mVEGF-A homodimers resulting in diminished tumor angiogenesis and reduced tumor infiltration by neutrophils, known to contribute to the angiogenic switch in Rip1Tag2 mice. The results indicate that the ratio between the expression levels of two members of the VEGF family of angiogenic factors, PlGF-1 and VEGF-A, determines the overall angiogenic activity and, thus, the extent of tumor angiogenesis and tumor growth.

The role of TRPV6 in breast carcinogenesis

TRPV6 is an endothelial calcium entry channel that is strongly expressed in breast adenocarcinoma tissue. In this study, we further confirmed this observation by analysis of breast cancer tissues, which indicated that TRPV6 mRNA expression was up-regulated between 2-fold and 15-fold compared with the average in normal breast tissue. Whereas TRPV6 is expressed in the cancer tissue, its role as a calcium channel in breast carcinogenesis is poorly understood. Therefore, we investigated how TRPV6 affects the viability, apoptosis, and calcium transport in the breast cancer cell line T47D. Hormones can also affect the tumor development; hence, we determined the effects of estradiol, progesterone, and 1,25-vitamin D on TRPV6 transcription. Interestingly, the estrogen receptor antagonist tamoxifen reduced expression of TRPV6 and is able to inhibit its calcium transport activity (IC(50), 7.5 micromol/L). The in vitro model showed that TRPV6 can be regulated by estrogen, progesterone, tamoxifen, and 1,25-vitamin D and has a large influence on breast cancer cell proliferation. Moreover, the effect of tamoxifen on cell viability was enhanced when TRPV6 expression was silenced with small interfering RNA. TRPV6 may be a novel target for the development of calcium channel inhibitors to treat breast adenocarcinoma expressing TRPV6.

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.

An Evaluation of Potential Occupational Exposure to Asbestiform Amphiboles near a Former Vermiculite Mine

Amphibole asbestos (AA) has been detected on the surface of tree bark in forests neighboring an abandoned vermiculite mine near Libby, Montana. In the present study, simulations were performed to assess potential AA exposure associated with United States Department of Agriculture Forest Service (FS) occupational activities. Bark samples were collected prior, and personal breathing zone (PBZ) and Tyvek clothing wipe samples were collected during and immediately after trials that simulated FS activities. Transmission electron microscopy (TEM) analyses revealed AA bark concentrations up to 15 million structures per square centimeter (s/cm2). AA was detected in 25% of the PBZ TEM samples. AA was detected on wipe samples collected from all activities evaluated. This research demonstrates the potential for airborne exposure and transport of AA in the Kootenai National Forest. These findings are especially relevant to those that work in the area and to the general public who may conduct recreational activities.

Occupational exposure to polycyclic aromatic hydrocarbons and DNA damage by industry: a nationwide study in Germany

Exposure to polycyclic aromatic hydrocarbons (PAH) and DNA damage were analyzed in coke oven (n = 37), refractory (n = 96), graphite electrode (n = 26), and converter workers (n = 12), whereas construction workers (n = 48) served as referents. PAH exposure was assessed by personal air sampling during shift and biological monitoring in urine post shift (1-hydroxypyrene, 1-OHP and 1-, 2 + 9-, 3-, 4-hydroxyphenanthrenes, SigmaOHPHE). DNA damage was measured by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and DNA strand breaks in blood post shift. Median 1-OHP and SigmaOHPHE were highest in converter workers (13.5 and 37.2 microg/g crea). The industrial setting contributed to the metabolite concentrations rather than the air-borne concentration alone. Other routes of uptake, probably dermal, influenced associations between air-borne concentrations and levels of PAH metabolites in urine making biomonitoring results preferred parameters to assess exposure to PAH. DNA damage in terms of 8-oxo-dGuo and DNA strand breaks was higher in exposed workers compared to referents ranking highest for graphite-electrode production. The type of industry contributed to genotoxic DNA damage and DNA damage was not unequivocally associated to PAH on the individual level most likely due to potential contributions of co-exposures.