Occupational exposures of firefighting and urinary tract cancer risk among men in the Norwegian Fire Departments Cohort

OBJECTIVES

Increased risks of bladder cancer and mesothelioma were the strongest evidence for the recent reclassification of firefighting as carcinogenic (Group 1) by the International Agency for Research on Cancer. Our study aim was to develop indicators for specific firefighting exposures and examine associations with urinary tract cancer (UTC), including bladder cancer.

METHODS

We developed indicators for exposure from employment at a fire department or in firefighting jobs, to fire and smoke, and to diesel exhaust for men in the Norwegian Fire Departments Cohort (n=4250). Incident UTC cases were obtained from the Cancer Registry of Norway (1960-2021). Poisson regression was used to estimate incidence rate ratios (IRR) with cumulative exposures grouped into tertiles (reference: lowest exposed tertile) with 0-year, 10-year and 15-year lagging of exposures.

RESULTS

During 125 090 person-years of follow-up, there were 76 cases of UTC. IRRs were mostly non-significantly increased in the middle tertile and at or below 1 in the highest tertile for total duration of employment, number of fires attended and fire exposure score with and without lags. In the middle tertile for diesel exhaust exposure, UTC risk was elevated over twofold with 10-year (IRR 2.27, 95% CI 1.22 to 4.20) and 15- year (2.21, 1.18 to 4.16) lags, and near 1 in the highest tertile. Findings for bladder cancer were similar to those for UTC.

CONCLUSIONS

Dose-response associations between the exposure indicators and UTC were not observed. Future studies using the indicators with more cases are needed.

Chloroform exposure in air and water in Swedish indoor swimming pools-urine as a biomarker of occupational exposure

INTRODUCTION

Disinfection by-products are produced in water disinfected with chlorine-based products. One such group is trihalomethanes, and chloroform is the most abundant trihalomethane in swimming pool areas. Chloroform can be absorbed by inhalation, ingestion, and dermal absorption, and is classified as possibly carcinogenic.

AIM

To investigate if chloroform concentrations in air and water affect the chloroform concentration in urine samples of exposed swimming pool workers.

METHODS

Workers from 5 adventure indoor swimming pools carried personal chloroform air samplers and provided up to 4 urine samples during one workday. Chloroform concentrations were analyzed with a linear mixed model analysis to investigate a possible correlation between air and urine concentrations.

RESULTS

The geometric mean chloroform concentration was 11 μg/m3 in air and 0.009 µg/g creatinine in urine among individuals with ≤2 h at work, 0.023 µg/g creatinine among those with >2-5 working hours, and 0.026 µg/g creatinine in the group with >5-10 working hours. A risk of higher levels of chloroform in urine was associated with longer hours at work (≤2 h versus >5-10 h, odds ratio [OR] 2.04, 95% confidence interval [CI] 1.25-3.34), personal chloroform concentrations in air (≤17.00 µg/m3 versus >28.00 µg/m3, OR 9.23, 95% CI 3.68-23.13) and working at least half the working day near the swimming pools (OR 3.16, 95% CI 1.33-7.55). Executing work tasks in the swimming pool water was not associated with higher chloroform concentrations in urine compared to only working on land (OR 0.82, 95% CI 0.27-2.45).

CONCLUSION

There is an accumulation of chloroform concentrations in urine during a workday and a correlation between personal air and urine concentrations of chloroform among workers in Swedish indoor swimming pools.

Anxiety in MINOCA patients according to latest definitions

Background

Anxiety is a global public health problem affecting the lives of large numbers of patients (pts) and their families. Some studies suggest that pts with MINOCA (myocardial infarction with non-obstructive coronary arteries) have more anxiety levels than the rest of pts with myocardial infarction (MI). The aim of this study is to compare anxiety levels between pts with MINOCA and the rest of MI pts using a validated scale: The State Trait Anxiety Inventory (STAI).

Methods

An analytical and observational study was developed in a University Hospital. We analysed the clinical data of all consecutive MI pts admitted to our centre from July 2017 to December 2020. Inclusion criteria were determined by the 4th Universal Definition of Myocardial Infarction and the latest definitions of MINOCA according to the 2020 ESC Guidelines. A group of experts reviewed all MINOCA cases in order to exclude those who did not fulfil the selection standards and takotsubo syndrome and myocarditis pts were excluded.

STAI questionnaire was completed by each patient during admission. Data collected included “trait anxiety”, that refers to relatively stable individual differences in anxiety-proneness, whereas “state anxiety” is a temporary emotion due to a particular situation (hospitalization in this case). Total score in each subgroup ranges from 0 to 60 points, where a higher score correlates with major anxiety levels.

Follow up analysis included major adverse cardiovascular events (MACE: cardiovascular readmission, myocardial reinfarction, stroke and death from any cause). Survival analysis is based on Cox regression. Median follow-up was 25±23 months.

Results

From a total of 413 consecutive MI pts, 243 (58.8%) completed the questionnaire. Of them, 32 (13%) were MINOCA pts. There were no significant differences in trait anxiety between both groups (MINOCA mean value 21±14 points vs rest of MI 19±10 points, p=0.9), nor in state anxiety (20±14 vs 19±10 points, p=0.8). There were also no significant differences when data were analysed by percentiles: 37.5% of MINOCA pts were below P25 and 28% of the rest of MI were also in this percentile. At the other end of the scale, 31.3% of MINOCA pts were above P75, as well as 22.7% of the rest of MI pts (table 1). During follow up, punctuation in trait anxiety in MINOCA pts showed no differences in MACE (HR 1.01, CI 95% (0.9–1.07)), nor did punctuation in state anxiety (HR 1.01, CI 95% (0.9–1.06)). This was also observed in the rest of MI pts: trait anxiety HR 1.01, CI 95% (0.9–1.04) and state anxiety HR 0.9, CI 95% (0.9–1.01).

Conclusion

In this study, there were no significant differences in anxiety levels between MINOCA pts and the rest of MI pts. The lack of takotsubo pts in this study reflect real data from MINOCA according to the latest definitions. Subjective emotions could lead to mistaken findings, making it necessary to determine emotional disorders with validated and objective tools.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): European Society of Cardiology Table 1. Percentile values of STAI.

Insomnia incidence in myocardial infarction with and without obstructive coronary arteries

Background

Insomnia can either be a primary problem or it may be associated with other psychological conditions, ranging from anxiety to depression. Some studies have reported that pts with MINOCA (myocardial infarction with non-obstructive coronary arteries) have more emotional disorders than the rest of pts with myocardial infarction (MI). However, a relationship with insomnia has not been yet described.

The aim of this study is to compare insomnia levels between patients with MINOCA and the rest of MI patients using a validated scale: Insomnia Severity Index (ISI) (Figure 1).

Methods

We performed an analytical and observational study in which all consecutive MI pts from July 2017 to December 2020 were recruited. We used the latest definitions of MINOCA according to the 2020 ESC Guidelines. A group of experts reviewed all MINOCA cases in order to exclude those who did not fulfil criteria. Therefore, takotsubo syndrome and pts with myocarditis were excluded.

ISI questionnaire was completed by each patient during admission. Total score ranges from 0 to 28 points. Depending on the final score, pts could have no clinically significant insomnia (0–7 points), subthreshold insomnia (8–14 points), clinical insomnia of moderate severity (15–21 points) and severe clinical insomnia (22–28 points).

Follow up analysis included major adverse cardiovascular events (MACE: cardiovascular readmission, myocardial reinfarction, stroke and death from any cause). Survival analysis is based on Cox regression. Median follow-up was 25±23 months.

Results

From a total of 413 consecutive MI pts, 244 (59%) completed the questionnaire. Of them, 32 (13%) were MINOCA pts. There were no statistically significant differences in insomnia levels between both groups (Table 1). Even in absolute terms, both groups presented same mean levels: MINOCA mean value 7.6±6 points vs rest of MI 7.7±6 points, p=0.8. When separated by sex, women in the MI group had higher punctuation levels than men (24% of moderate clinical insomnia in women vs 8.9% of men, p=0.03). Punctuation in ISI questionnaire showed no significant differences in MACE in MINOCA pts (HR 0.9, CI 95% (0.7–1.2)), nor in the rest of MI pts (HR 0.9, CI 95% (0.9–1.03)).

Conclusions

Levels of insomnia were similar in MINOCA pts than in the rest of MI pts. Follow up showed no differences in MACE between both groups regarding insomnia according to ISI. Women had higher punctuation levels than men, with more clinical insomnia in a moderate grade. Subjective emotions could lead to mistaken findings, making it necessary to use ISI questionnaire or other objective validated scales to correctly study some disorders and their distribution in different populations.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Society of Cardiology Table 1. Insomnia severity indexFigure 1. ISI Questionnaire

The SπRIT time projection chamber

The Superconducting Analyzer for MUlti-particles from RAdioIsotope (SAMURAI) Pion-Reconstruction and Ion-Tracker Time Projection Chamber (SπRIT TPC) was designed to enable measurements of heavy ion collisions with the SAMURAI spectrometer at the RIKEN radioactive isotope beam factory and provides constraints on the equation of state of neutron-rich nuclear matter. The SπRIT TPC has a 50.5 cm drift length and an 86.4 × 134.4 cm² pad plane with 12 096 pads that are equipped with the generic electronics for TPCs. The SπRIT TPC allows for an excellent reconstruction of particles and provides isotopic resolution for pions and other light charged particles across a wide range of energy losses and momenta. The details of the SπRIT TPC are presented, along with discussion of the TPC performance based on cosmic rays and charged particles emitted in heavy ion collisions.

Occupational Exposure during Asphalt Paving-Comparison of Hot and Warm Mix Asphalt in Field Experiments

OBJECTIVES

Several studies have demonstrated an increased risk of adverse health effects, including reduced lung function and lung cancer among asphalt pavers, which has been related to occupational exposure to contaminants during asphalt paving. Consequently, occupational exposure among asphalt pavers must be reduced. The aim of this study was to compare the impact of hot mix asphalt (HMA) and warm mix asphalt (WMA) paving on occupational exposure levels during road paving in field experiments. Asphalt temperatures when paving with WMA are usually lower than when paving with HMA due to differences in the asphalt's composition and method of application.

METHODS

On 11 different road sections, one lane was paved with WMA and one with HMA during the same work shift under approximately identical weather conditions. The weather conditions and asphalt surface temperature were monitored during paving. Fifty-seven samples of fumes and vapor, organic and elemental carbon, amines, and respirable, thoracic, and inhalable particulate matter (PM) fractions were collected by stationary sampling. In addition, 30 samples of fumes and vapor were collected by personal sampling.

RESULTS

Compared to paving with HMA, paving with WMA significantly (P < 0.05; paired Student's t-test) reduced the geometric mean (GM) air concentration of asphalt vapor (0.04 versus 0.08 p.p.m.), organic carbon (OC; 0.09 versus 0.18 mg m-3), and respirable PM (0.12 versus 0.22 mg m-3). Additionally, the air concentration of OC correlated strongly with the respirable fraction of PM (Pearson's correlation coefficient 0.83).

CONCLUSIONS

Measured airborne concentrations of respirable PM, OC, and asphalt vapor were lower when paving with WMA than with HMA. Because exposure to airborne contaminants generated during asphalt paving is believed to be responsible for the adverse health effects observed among asphalt pavers, paving with WMA rather than HMA may have health benefits.

Exposure Determinants of Wood Dust, Microbial Components, Resin Acids and Terpenes in the Saw- and Planer Mill Industry

Objectives

Sawmill workers have an increased risk of adverse respiratory outcomes, but knowledge about exposure–response relationships is incomplete. The objective of this study was to assess exposure determinants of dust, microbial components, resin acids, and terpenes in sawmills processing pine and spruce, to guide the development of department and task-based exposure prediction models.

Methods

2474 full-shift repeated personal airborne measurements of dust, resin acids, fungal spores and fragments, endotoxins, mono-, and sesquiterpenes were conducted in 10 departments of 11 saw- and planer mills in Norway in 2013–2016. Department and task-based exposure determinants were identified and geometric mean ratios (GMRs) estimated using mixed model regression. The effects of season and wood type were also studied.

Results

The exposure ratio of individual components was similar in many of the departments. Nonetheless, the highest microbial and monoterpene exposure (expressed per hour) were estimated in the green part of the sawmills: endotoxins [GMR (95% confidence interval) 1.2 (1.0–1.3)], fungal spores [1.1 (1.0–1.2)], and monoterpenes [1.3 (1.1–1.4)]. The highest resin acid GMR was estimated in the dry part of the sawmills [1.4 (1.2–1.5)]. Season and wood type had a large effect on the estimated exposure. In particular, summer and spruce were strong determinants of increased exposure to endotoxin (GMRs [4.6 (3.5–6.2)] and [2.0 (1.4–3.0)], respectively) and fungal spores (GMRs [2.2 (1.7–2.8)] and [1.5 (1.0–2.1)], respectively). Pine was a strong determinant for increased exposure to both resin acid and monoterpenes. Work as a boilerman was associated with moderate to relatively high exposure to all components [1.0–1.4 (0.8–2.0)], although the estimates were based on 13–15 samples only. Cleaning in the saw, planer, and sorting of dry timber departments was associated with high exposure estimates for several components, whereas work with transportation and stock/finished goods were associated with low exposure estimates for all components. The department-based models explained 21–61% of the total exposure variances, 0–90% of the between worker (BW) variance, and 1–36% of the within worker (WW) variances. The task-based models explained 22–62% of the total variance, 0–91% of the BW variance, and 0–33% of the WW variance.

Conclusions

Exposure determinants in sawmills including department, task, season, and wood type differed for individual components, and explained a relatively large proportion of the total variances. Application of department/task-based exposure prediction models for specific exposures will therefore likely improve the assessment of exposure–response associations.

Work Conditions and Practices in Norwegian Fire Departments From 1950 Until Today: A Survey on Factors Potentially Influencing Carcinogen Exposure

BACKGROUND

Meta-analyses have shown firefighters to be at an increased risk of several cancer types. Occupational carcinogen exposure may explain these increased risks. This study aims to describe Norwegian fire departments' work conditions from 1950 until today, focusing on factors relevant for potential occupational carcinogen exposure.

METHODS

With the help of a reference group, we developed a questionnaire on topics related to occupational exposure to carcinogens for the period 1950-2018. Selected Norwegian fire departments provided department-specific responses.

RESULTS

Sixteen departments, providing fire services for 48% of the Norwegian population as of 2019 and mainly consisting of professional firefighters, responded to our questionnaire. The introduction of synthetic firefighting foams, more regular live fire training, the introduction of chemical diving, and a higher number of diesel-driven fire service vehicles were identified as changes thought to increase exposure to occupational carcinogens. Changes thought to decrease exposure included the switch from negative to positive pressure self-contained breathing apparatuses, the use of self-contained breathing apparatuses during all phases of firefighting, the use of ventilating fans during firefighting, increased attention to flammable materials used during live fire training, increased attention to handling and cleaning of turnout gear and other equipment, and installment of exhaust removal systems in apparatus bays.

CONCLUSION

Norwegian fire departments' work conditions have seen several changes since 1950, and this could influence firefighters' occupational carcinogen exposure. A peak of carcinogen exposure may have occurred in the 1970s and 1980s before recent changes have reduced exposure.

Reactive hyperemia and baseline pulse amplitude among smelter workers exposed to fine and ultrafine particles

Objective

Ambient exposure to fine particles is associated with increased cardiovascular morbidity and mortality. Associations between occupational particulate matter (PM) exposure and cardiovascular disease have been studied less. The objective of this study was to examine associations between PM exposure and endothelial function among workers in Norwegian smelters.

Methods

We examined endothelial function with Endo-PAT equipment after a working day (WD) and on a day off (DO) in 59 furnace workers recruited from three metal smelters in Norway. The difference in baseline pulse amplitude (BPA) and reactive hyperemia index (RHI) between the 2 days was analysed in relation to individual exposure to PM < 250 nm (PM₂₅₀) or the respirable aerosol fraction of particles, and adjusted for relevant covariates.

Results

The exposure to PM₂₅₀ ranged from 0.004 to 5.7 mg/m³. The mean BPA was significantly higher on WD relative to DO (772 vs. 535, p = 0.001). This difference was associated with PM concentrations among participants ≥ 34 years, but not among the younger workers. Reactive hyperemia was significantly lower on workdays relative to days off (1.70 vs. 1.84, p = 0.05). This difference was observed only among participants above the age 34. No associations with PM exposure were observed.

Conclusions

PM exposure was associated with higher BPA among participants older than 34 years. BPA reflects microvessel pulsatility. Our results may indicate an age-dependent cardiovascular susceptibility to PM exposure. Endothelial function measured by RHI was reduced on WD among participants 34 years and older, but we found no associations between PM exposure and RHI.

Occupational exposure during treatment of offshore drilling waste and characterization of microbiological diversity

The exposure for workers handling and recycling offshore drilling waste are previously not described, and given the potential for exposure to hazardous components, there is a need for characterizing this occupational exposure. In this study five plants recycling offshore drilling waste with different techniques were included. Measurements were conducted in both winter and summer to include seasonal exposure variations. Altogether >200 personal air-exposure measurements for oil mist, oil vapor, volatile organic compounds (VOC), hydrogen sulfide (H₂S) and solvents were carried out respectively. Microorganisms related to drilling waste were identified in bulk samples and in stationary air measurements from two of the plants. The exposure to oil mist and oil vapor were below 10% of the current Norwegian occupational exposure limits (OEL) for all measured components. The plants using the Resoil or TCC method had a statistically significant higher exposure to oil vapor than the plant using complete combustion (p-value <0.05). No statistically significant difference was found between the different treatment methods for oil mist. The exposure to solvents was generally low (additive factor < 0.03). Endotoxin measurements done during winter showed a median concentration of 5.4 endotoxin units (EU)/m³. Levels of H₂S above the odor threshold of 0.1 ppm were measured at four plants. Both drill mud and slop water contained a high number and diversity of bacteria (2-4 × 10⁴ colony forming unit (CFU)/mL), where a large fraction was Gram-negative species. Some of the identified microorganisms are classified as potentially infectious pathogens for humans and thus might be a hazard to workers.

Vascular component of hand-arm vibration syndrome: a 22-year follow-up study

BACKGROUND

Vibration-induced white finger (VWF) is often assessed using the Stockholm Workshop Scale (SWS) and cold challenge plethysmography. However, long-term longitudinal studies using both methods are scarce.

AIMS

To study the long-term course and prognostic factors of VWF assessed with the SWS and photoplethysmography (PPG), and to examine the effects of lifestyle on PPG score, regardless of VWF status.

METHODS

Forty male construction workers were examined with a test battery and clinical examination in 1994 and 2016/17.

RESULTS

At baseline, the sample comprised 27 workers with, and 13 without, symptoms of hand-arm vibration syndrome (HAVS). Thirty-five workers reported vibration exposure during follow-up. The mean age of the workers was 60 years (45-78) at follow-up. The paired t-test showed that PPG scores deteriorated from 1994 to 2017 in the 27 workers with HAVS in 1994 (mean difference 2.7 min, 95% confidence interval (CI) 0.2-5.2). However, there was no statistically significant change in SWS scores in these workers over time. Smoking and age were associated with PPG score deterioration. Vibration exposure during follow-up predicted SWS score deterioration: 1000 h of exposure predicted a deterioration stage of 0.09 (95% CI 0.03-0.16). Analysis of all 40 workers showed that 2017 PPG scores were associated with positive serum cotinine and self-reported smoking during follow-up.

CONCLUSIONS

Whereas age and smoking predicted a PPG deterioration, continued vibration exposure predicted worsening of white finger symptoms. The association of PPG score and smoking should be considered in diagnostic and prognostic factor evaluations.

Exposure to Wood Dust, Microbial Components, and Terpenes in the Norwegian Sawmill Industry

Sawmill workers are exposed to wood dust (a well-known carcinogen), microorganisms, endotoxins, resin acids (diterpenes), and vapours containing terpenes, which may cause skin irritation, allergy, and respiratory symptoms including asthma. The health effects of most of these exposures are poorly understood as most studies measure only wood dust. The present study assessed these exposures in the Norwegian sawmill industry, which processes predominantly spruce and pine. Personal exposures of wood dust, resin acids, endotoxin, fungal spores and fragments, mono-, and sesquiterpenes were measured in 10 departments in 11 saw and planer mills. The geometric mean (GM) and geometric standard deviation (GSD) thoracic exposures were: 0.09 mg m-3 dust (GSD 2.6), 3.0 endotoxin units (EU) m-3 (GSD 4.9), 0.4 × 105 fungal spores m-3 (GSD 4.2), 2 × 105 fungal fragments m-3 (GSD 3.2), and 1560 ng m-3 of resin acids (GSD 5.5). The GM (GSD) inhalable exposures were: 0.72 mg m-3 dust (2.6), 17 EU m-3 (4.3), 0.4 × 105 fungal spores m-3 (3.8), and 7508 ng m-3 (4.4) of resin acids. The overall correlation between the thoracic and inhalable exposure was strong for resin acid (rp = 0.84), but moderate for all other components (rp = 0.34-0.64). The GM (GSD) exposure to monoterpenes and sesquiterpenes were 1105 µg m-3 (7.8) and 40 µg m-3 (3.9), respectively. Although mean exposures were relatively low, the variance was large, with exposures regularly exceeding the recommended occupational exposure limits. The exposures to spores and endotoxins were relatively high in the dry timber departments, but exposures to microbial components and mono-and sesquiterpenes were generally highest in areas where green (undried) timber was handled. Dust and resin acid exposure were highest in the dry areas of the sawmills. Low to moderate correlation between components (rp ranging from 0.02 to 0.65) suggests that investigations of exposure-response associations for these components (both individually and combined) are feasible in future epidemiological studies.

Elevated plasma levels of P-selectin glycoprotein ligand-1-positive microvesicles in patients with unprovoked venous thromboembolism

Essentials PSGL-1+ microvesicles (MVs) may be important in venous thromboembolism (VTE). We measured plasma levels and parental origin of PSGL-1+ MVs in patients with unprovoked VTE. VTE patients had higher plasma levels of PSGL-1+ MVs than healthy controls. The PSGL-1+ MVs originated mainly from monocytes and endothelial cells.

SUMMARY

Background Microvesicles (MVs) express antigens from their parental cells and have a highly procoagulant surface. Animal studies suggest that P-selectin glycoprotein ligand-1-positive (PSGL-1+ ) MVs play a role in the pathogenesis of venous thromboembolism (VTE). Objective The aim of this study was to determine plasma levels, the cellular origin and the morphological characteristics of PSGL-1+ MVs in patients with unprovoked VTE. Methods We conducted a population-based case-control study in 20 patients with a history of unprovoked VTE and 20 age- and sex-matched healthy controls recruited from the general population. Plasma levels, the cellular origin and the morphological characteristics of PSGL-1+ MVs were evaluated using flow cytometry, electron microscopy and confocal microscopy. Results Plasma levels of PSGL-1+ MVs were associated with increased risk of VTE. The odds ratio per one standard deviation increase in PSGL-1+ MVs was 3.11 (95% confidence interval [CI], 1.41-6.88) after adjustment for age and sex, and 2.88 (95% CI, 1.29-6.41) after further adjustment for body mass index. The PSGL-1+ MVs originated mainly from monocytes and endothelial cells determined by double staining with markers of parental cells using flow cytometry and transmission electron microscopy. Scanning electron microscopy of PSGL-1-labeled plasma-derived MVs displayed dominantly spherical vesicles that varied between 50 and 300 nm in diameter. Conclusions Increased plasma levels of PSGL-1+ MVs are associated with the risk of unprovoked VTE. Large population-based prospective studies are required to validate our findings.

Impact of egg disinfection of hatching eggs on the eggshell microbiome and bacterial load

Disinfection of hatching eggs is essential to ensure high quality production of broilers. Different protocols are followed in different hatcheries; however, only limited scientific evidence on how the disinfection procedures impact the microbiome is available. The aim of the present study was to characterize the microbiome and aerobic bacterial load of hatching eggs before disinfection and during the subsequent disinfection steps. The study included a group of visibly clean and a group of visibly dirty eggs. For dirty eggs, an initial wash in chlorine was performed, hereafter all eggs were submitted to two times fumigation and finally spray disinfection. The eggshell microbiome was characterized by sequencing of the total amount of 16S rRNA extracted from each sample, consisting of shell surface swabs of five eggs from the same group. In addition, the number of colony forming units (cfu) under aerobic conditions was established for each disinfection step. The disinfection procedure reduced the bacterial load from more than 104 cfu (initially visibly clean eggs) and 105 cfu (initially visibly dirty eggs) to less than 10 cfu per sample after disinfection for both groups of eggs. The microbiome of both initially visibly clean and initially visibly dirty eggs had the highest abundances of the phyla Firmicutes, Proteobacteria and Bacteroidetes. Within the phyla Firmicutes the relative abundances of Clostridiales decreased while Lactobacillus increased from before to after final disinfection. In conclusion, the investigated disinfection procedure is effective in reducing the bacterial load, and by adding a chlorine wash for initially visibly dirty eggs, the microbiome of initially visibly clean and initially visibly dirty eggs had a highly similar microflora after the final disinfection step.

Effect of reduced protein intake on endurance performance and water turnover during low intensity long duration exercise in Alaskan sled dogs

Increased nutritional demands for endurance exercise of dogs are typically met through increased amounts of their current food. As a result, protein intake is also increased, and excessive nitrogen may affect the dog’s water balance. Sixteen unconditioned Alaskan sled dogs underwent a 6-week exercise training protocol, wherein 8 dogs were fed increasing amounts of their normal kibble to maintain body weight, while the other 8 were fed the same amount of kibble, with increasing calorie needs met by equal amounts of sugar and oil. The diets resulted in similar calorie intakes (181.3±20.0 and 205.7±36.3 kcal/kg0.75, for the control and low protein dogs respectively) but control dogs had higher protein intakes (32.2±0.0 and 19.4±2.4% of metabolic energy intake). After 6 weeks of training the dogs completed a 5 day exercise test in which they travelled 24 km per day, where total energy expenditure was determined using doubly-labelled water technique. Dogs expended an average of 1,491±264 kcal/day (145±25 kcal/kg0.75/day), with no difference between the dietary treatments and no negative performance indicators. Following the exercise test the dogs underwent a 24 hour dehydration test (water withheld) followed by an 8 hour rehydration test (with ad libitum water intake recorded) where total body water was determined using deuterium oxide. Blood and urinary samples were also collected. Following exercise conditioning, control dogs had higher serum urea nitrogen than low protein dogs, and this as well as albumin decreased further during the 5 day exercise test. Low-protein dogs had lower overall total body water and higher fractional excretion of Na+, suggesting some renal adaptation. These findings suggest that reduced protein intake did not negatively affect athletic performance, though some facets of body chemistry were altered.

Correction: The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres

Correction for 'The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres' by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2014, 16, 2423-2431.

Correction: The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements

Correction for 'The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements' by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2016, 18, 810-818.

Correction: Comparison of air samplers for determination of isocyanic acid and applicability for work environment exposure assessment

Correction for 'Comparison of air samplers for determination of isocyanic acid and applicability for work environment exposure assessment' by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2017, 19, 1075-1085.

Pulmonary function and high-resolution computed tomography examinations among offshore drill floor workers

Purpose

The aim of this study was to assess short-term changes in pulmonary function in drill floor workers currently exposed to airborne contaminants generated as a result of drilling offshore. We also aimed to study the prevalence of pulmonary fibrosis using high-resolution computed tomography (HRCT) scans of another group of previously exposed drill floor workers.

Methods

Pulmonary function was measured before and after a 14-day work period in a follow-up study of 65 drill floor workers and 65 referents. Additionally, 57 other drill floor workers exposed to drilling fluids during the 1980s were examined with HRCT of the lungs in a cross-sectional study.

Results

The drill floor workers had a statistically significant decline in forced expiratory volume in 1 s (FEV₁) across the 14-day work period after adjustment for diurnal variations in pulmonary function (mean 90 mL, range 30–140 mL), while the small decline among the referents (mean 20 mL, range − 30 to 70 mL) was not of statistical significance. Larger declines in FEV₁ among drill workers were associated with the fewer number of days of active drilling. There were no signs of pulmonary fibrosis related to oil mist exposure among the other previously exposed drill floor workers.

Conclusion

After 14 days offshore, a statistically significant decline in FEV₁ was observed in the drill floor workers, which may not be related to oil mist exposure. No pulmonary fibrosis related to oil mist exposure was observed.

Comparison of air samplers for determination of isocyanic acid and applicability for work environment exposure assessment

Isocyanic acid (ICA) is one of the most abundant isocyanates formed during thermal decomposition of polyurethane (PUR), and other nitrogen containing polymers. Hot-work, such as flame cutting, forging, grinding, turning and welding may give rise to thermal decomposition of said polymers potentially forming significant amounts of ICA. A newly launched dry denuder sampler for airborne isocyanates using di-n-butylamine (DBA) demonstrated build-up of background ICA-DBA over time. Build-up of background ICA-DBA was not observed when stored at inert conditions (Ar atmosphere) for 84 days. Thus, freshly prepared denuders were used. The sampling efficiency of ICA using freshly prepared denuder samplers (0.2 L min^-1), impinger + filter samplers (0.5 L min^-1) using DBA and 1-(2-methoxyphenyl) piperazine (2MP)-impregnated filter cassette samplers (1 L min^-1) was investigated. PTR-MS measurements of ICA were used as a quantitative reference. Dynamically generated standard ICA atmospheres covered the range 5.6 to 640 ppb at absolute humidities (AH) 4.0 and 16 g m^-3. Recovered ICA was found to be 73-115% (denuder), 89-115% (impinger + filter) and 62-100% (2MP filter cassette). The method limit of detection (LOD) was equal to an amount of ICA of 24 ng (denuder), 8.9 ng (impinger + filter) and 9.4 ng (2MP filter cassette). The PTR-MS LOD for ICA was 1.8 and 2.8 ppb in atmospheres with an AH of 4 and 16 g m^-3. Denuder samplers were used for personal (n = 176) and stationary (n = 31) air sampling during hot-work at six industrial sites (n = 23 workers). ICA was detected above method LOD in 66% and 58% of the personal and stationary samples, respectively. ICA workroom air concentrations were determined to be 1.8-320 ppb (median 12 ppb) (personal samples), and 1.5-44 ppb (median 6.6 ppb) (stationary samples).

Tremor and hand-arm vibration syndrome (HAVS) in road maintenance workers

Objectives

The aim of this study was to evaluate postural and rest tremor among workers using vibrating hand tools, taking into account the possible effects of toxicants such as alcohol and tobacco. A further aim was to study workers diagnosed with hand-arm vibration syndrome (HAVS) at the time of examination.

Methods

This study comprises 103 road maintenance workers, 55 exposed to vibrating hand tools (age 41.0 years; range 21–62) and 48 referents (age 38.5 years; range 19–64). They were examined with the CATSYS Tremor Pen^®. Exposure to vibrating tools and serum biomarkers of alcohol and tobacco consumption were measured.

Results

Cumulative exposure to vibrating tools was associated with increased postural (p < 0.01) and rest tremor (p < 0.05) and with a higher Center Frequency of postural tremor (p < 0.01) among smokers and users of smokeless tobacco. Rest tremor Center Frequency was higher than postural tremor frequency (p < 0.001).

Conclusions

The main findings indicate an association between cumulative exposure to hand-held vibrating tools, tremor parameters and consumption of tobacco products. The hand position is important when testing for tremor. Rest tremor had a higher Center Frequency. Postural tremor was more strongly associated with exposure than rest tremor. The finding of increased tremor among the HAVS subjects indicated that tremor might be a part of the clinical picture of a HAVS diagnosis. As with all cross-sectional studies, inferences should be made with caution when drawing conclusions about associations between exposure and possible effects. Future research using longitudinal design is required to validate the findings of the present study.

The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements

Isocyanic acid (ICA) in vapour phase has been reported to be of unstable nature, making the occupational hygienic relevance of ICA questionable. The stability of pure ICA in clean air at different humidity conditions was investigated by Fourier transform-infrared spectrometric (FT-IR) measurements. Furthermore, the stability of ICA in a complex atmosphere representative thermal degradation hot-work procedures were examined by performing parallel measurements by proton transfer reaction-mass spectrometric (PTR-MS) instrumentation and off-line denuder air sampling using di-n-butylamine (as a derivatization agent prior to liquid chromatography mass spectrometric (LC-MS) determination). The apparent half-life of ICA in pure ICA atmospheres was 16 to 4 hours at absolute humidity (AH) in the range 4.2 to 14.6 g m(-3), respectively. In a complex atmosphere at an initial AH of 9.6 g m(-3) the apparent half-life of ICA was 8 hours, as measured with the denuder method. Thus, thermally formed ICA is to be considered as a potential occupational hazard with regard to inhalation. The generation pattern of ICA formed during controlled gradient (100-540 °C) thermal decomposition of different polymers in the presence of air was examined by parallel PTR-MS and denuder air sampling. According to measurement by denuder sampling ICA was the dominant aliphatic isocyanate formed during the thermal decomposition of all polymers. The real-time measurements of the decomposed polymers revealed different ICA generation patterns, with initial appearance of thermally released ICA in the temperature range 200-260 °C. The PTR-MS ICA measurements was however affected by mass overlap from other decomposition products at m/z 44, illustrated by a [ICA]Denuder/[ICA]PTR-MS ratio ranging from 0.04 to 0.90. These findings limits the potential use of PTR-MS for real time measurements of thermally released ICA in field, suggesting parallel sampling with short-term sequential off-line methodology.

Caffeine improves performance in double poling during acute exposure to 2,000-m altitude

There is limited research on the physiological effects of caffeine (CAF) ingestion on exercise performance during acute hypoxia. The aim of the present study was therefore to test the effect of placebo (PLA) and CAF (4.5 mg/kg) on double poling (DP) performance during acute hypoxia. Thirteen male subelite cross-country skiers (V̇o2max 72.6 ± 5.68 ml·kg−1·min−1) were included. Performance was assessed as 1) an 8-km cross-country DP time-trial (C-PT), and 2) time until task failure at a set workload equal to ∼90% of DP V̇o2max. Testing was carried out in a hypobaric chamber, at 800 mbar (Pio2: ∼125 mmHg) corresponding to ∼2,000 m above sea level in a randomized double-blinded, placebo-controlled, cross-over design. CAF improved time to task failure from 6.10 ± 1.40 to 7.22 ± 1.30 min ( P < 0.05) and velocity the first 4 km ( P < 0.05) but not overall time usage for the 8-km C-PT. During submaximal exercise subjects reported lower pain in arms and rate of perceived exertion (RPE) following CAF ingestion. Throughout C-PTs similar RPE and pain was shown between treatments. However, higher heart rate was observed during the CAF 8 km (187 ± 7 vs. 185 ± 7; P < 0.05) and 90% C-PT (185 ± 7 vs. 181 ± 9) associated with increased ventilation, blood lactate, glucose, adrenaline, decreased pH, and bicarbonate. The present study demonstrates for the first time that CAF ingestion improves DP time to task failure although not consistently time trial performance during acute exposure to altitude. Mechanisms underpinning improvements seem related to reduced pain RPE and increased heart rate during CAF C-PTs.

The impact of psychosis on the course of cognition: a prospective, nested case-control study in individuals at clinical high-risk for psychosis

BACKGROUND

Although cognitive deficits in patients with schizophrenia are rooted early in development, the impact of psychosis on the course of cognitive functioning remains unclear. In this study a nested case-control design was used to examine the relationship between emerging psychosis and the course of cognition in individuals ascertained as clinical high-risk (CHR) who developed psychosis during the study (CHR + T).

METHOD

Fifteen CHR + T subjects were administered a neurocognitive battery at baseline and post-psychosis onset (8.04 months, s.d. = 10.26). CHR + T subjects were matched on a case-by-case basis on age, gender, and time to retest with a group of healthy comparison subjects (CNTL, n = 15) and two groups of CHR subjects that did not transition: (1) subjects matched on medication treatment (i.e. antipsychotics and antidepressants) at both baseline and retesting (Meds-matched CHR + NT, n = 15); (2) subjects unmedicated at both assessments (Meds-free CHR + NT, n = 15).

RESULTS

At baseline, CHR + T subjects showed large global neurocognitive and intellectual impairments, along with specific impairments in processing speed, verbal memory, sustained attention, and executive function. These impairments persisted after psychosis onset and did not further deteriorate. In contrast, CHR + NT subjects demonstrated stable mild to no impairments in neurocognitive and intellectual performance, independent of medication treatment.

CONCLUSIONS

Cognition appears to be impaired prior to the emergence of psychotic symptoms, with no further deterioration associated with the onset of psychosis. Cognitive deficits represent trait risk markers, as opposed to state markers of disease status and may therefore serve as possible predictors of schizophrenia prior to the onset of the full illness.

Caffeine and performance over consecutive days of simulated competition

PURPOSE

Performance improvements after caffeine (CAF) ingestion are well documented when using a 1-d protocol. In numerous competitions such as the Tour de France, Tour de Ski, world championships, and National College Athletic Association championships, athletes compete for several days in a row. To date, no studies have investigated the effects of CAF when competing for consecutive days in a row. This study aimed to investigate the effects of placebo (PLA) and two different CAF doses (3 and 4.5 mg·kg body mass) on performance in a 10-min all-out, cross-country, double poling ergometer test (C-PT) 2 d in a row.

METHOD

Eight highly trained male cross-country skiers (V˙O2max-run, 78.5 ± 1.6 mL·kg·min) participated in the study, which was a randomized, double-blind, PLA-controlled, crossover design. Performance was assessed as distance covered during a 10-min all-out C-PT. Oral ingestion of CAF or PLA was consumed 75 min before the all-out C-PT.

RESULTS

Poling distance was improved after CAF ingestions compared with that after PLA on both days. The improvements on day 1 were 4.0% (90% confidence limits, ±3.3) and 4.0% ± 2.9% for both CAF doses, respectively (P < 0.05), whereas improvements on day 2 were 5.0% ± 3.6% and 5.1% ± 2.8% for CAF3 and CAF4.5, respectively, compared with those for PLA. Improved performance was associated with increased HR, adrenaline concentration, blood lactate concentration, and V˙O2 consumption after CAF ingestion. Furthermore, performance was elevated despite higher creatine kinase concentration and muscular pain at arrival on day 2 for both CAF doses.

CONCLUSIONS

Both CAF doses improved performance in the 10-min all-out C-PT compared with PLA over two consecutive days. Therefore, CAF seems useful for athletes competing over consecutive days despite higher muscle damage occurring after enhanced performance on the first day.

Occupational exposure assessment of airborne chemical contaminants among professional ski waxers

BACKGROUND

Ski waxes are applied onto the skis to improve the performance. They contain different chemical substances, e.g. perfluoro-n-alkanes. Due to evaporation and sublimation processes as well as mechanically generated dust, vapours, fumes, and particulates can contaminate the workroom atmosphere. The number of professional ski waxers is increasing, but occupational exposure assessments among professional ski waxers are lacking.

OBJECTIVES

The aim was to assess exposure to airborne chemical contaminants among professional ski waxers. It was also a goal to construct a ventilation system designed for ski waxing work operations.

METHODS

Forty-five professional ski waxers were included. Personal measurements of the inhalable and the respirable aerosol mass fractions were executed in 36 different waxing cabins using Conical Inhalable Sampler cassettes equipped with 37-mm PVC filters (5 µm) and Casella respirable cyclones equipped with 37-mm PVC filters (0.8 µm), respectively. Volatile organic components were collected using Anasorb CSC charcoal tubes. To examine time trends in exposure patterns, stationary real-time measurements of the aerosol mass fractions were conducted using a direct-reading Respicon® sampler.

RESULTS

Mean aerosol particle mass concentrations of 3.1 mg·m(-3) (range: 0.2-12.0) and 6.2 mg·m(-3) (range: 0.4-26.2) were measured in the respirable and inhalable aerosol mass fractions, respectively. Real-time aerosol sampling showed large variations in particle concentrations, with peak exposures of ~10 and 30 mg·m(-3) in the respirable and the inhalable aerosol particle mass fractions, respectively. The custom-made ventilation system reduced the concentration of all aerosol mass fractions by more than 90%.

The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres

A method is presented for the real-time quantitative determination of isocyanic acid (ICA) in air using proton transfer reaction-mass spectrometry (PTR-MS). Quantum mechanical calculations were performed to establish the ion-polar molecule reaction rate of ICA and other isocyanates. The PTR-MS was calibrated against different ICA air concentrations and humidity conditions using Fourier transform-infrared spectroscopy (FT-IR) as quantitative reference. Based on these experiments a simple humidity dependant model was derived for correction of the PTR-MS response for ICA. The corrected PTR-MS data was linearly correlated (R(2) > 0.99) with the data acquired by FT-IR. The PTR-MS instrumental limit of detection (LOD) for ICA was 2.3 ppb. Humid atmospheres resulted in LODs of 3.4 and 7.8 ppb, at an absolute humidity (AH) of 4.0 and 15.5 g m(-3), respectively. Furthermore, off-line sampling using denuder and impinger samplers using di-n-butylamine (DBA) as derivatization reagent was compared with PTR-MS measurements in a dynamically generated standard ICA atmosphere. Denuder (n = 4) and impinger (n = 4) sampling subsequent to liquid chromatography mass spectrometry (LC-MS) determination compared to corrected PTR-MS data resulted in recoveries of 79.6 (8.1% RSD) and 99.9 (9.3% RSD) %, respectively. Measurements of ICA from thermally decomposed cured 1,6-hexamethylene diisocyanate (HDI)-paint was performed using PTR-MS and denuder (n = 3) sampling. The relation between the average ICA responses using denuders (34.4 ppb) and PTR-MS (42.6 ppb) was 80.6%, which coincided well with the relative recovery obtained from the controlled laboratory experiments using dynamically generated ICA atmospheres (79.6%). The variability in ICA air concentration during the welding process (170% RSDPTR-MS) illustrated the need for real-time measurements.

Luminal uptake of Vibrio (Listonella) anguillarum by shed enterocytes--a novel early defence strategy in larval fish

As adhesion and translocation through fish gut enterocytes of the pathogen Vibrio (Listonella) anguillarum are not well investigated, the effective cause of disease and mortality outbreaks in larval sea bass, Dicentrarchus labrax, suffering from vibriosis is unknown. We detected V. anguillarum within the gut of experimentally infected gnotobiotic sea bass larvae using transmission electron microscopy and immunogold labelling. Intact bacteria were observed in close contact with the apical brush border in the gut lumen. Enterocytes contained lysosomes positive for protein A-gold particles suggesting intracellular elimination of bacterial fragments. Shed intestinal cells were regularly visualized in the gut lumen in late stages of exposure. Some of the luminal cells showed invagination and putative engulfment of bacterial structures by pseudopod-like formations. The engulfed structures were positive for protein A-colloidal gold indicating that these structures were V. anguillarum. Immunogold positive thread-like structures secreted by V. anguillarum suggested the presence of outer membrane vesicles (MVs) hypothesizing that MVs are potent transporters of active virulence factors to sea bass gut cells suggestive for a substantial role in biofilm formation and pathogenesis. We put forward the hypothesis that MVs are important in the pathogenesis of V. anguillarum in sea bass larvae.

Occupational exposure to airborne perfluorinated compounds during professional ski waxing

The concentration levels of 11 perfluorinated carboxylic (PFCA) and eight sulfonic (PFSA) acids were determined in the serum of 13 professional ski waxers. The same components were also determined in workroom aerosols and in fluoro containing solid ski waxes and ski wax powders. The highest median concentration (50 ng/mL) was detected for perfluorooctanoic acid (PFOA), which is around 25 times higher than the background level. For the first time perfluorotetradecanoic acid (PFTeDA) has been found in human serum. Positive statistically significant associations between years exposed as ski waxer and seven different PFCAs were observed. The serum concentrations of the PFCAs with carbon chain lengths from C(8) to C(11) were reduced by around five to 20% on average during the eight month exposure free interval, whereas the reduction was substantially larger when the carbon chain lengths were smaller than C(8) or larger than C(11). This study links for the first time PFCAs in the ski waxers serum to exposure from the work room aerosols. Not only professional ski waxers but also the significant larger group of amateur skiers and waxers are potentially exposed to these compounds.

Conditioned suppression as a sensitive baseline for social facilitation

The key pecking of pigeons maintained on a variable-interval schedule of food reinforcement was suppressed during occasional presentations of a warning stimulus paired with electric shock. On alternate sessions, a co-actor pigeon was visible in an adjoining chamber where it emitted the same food-reinforced key peck during the warning stimulus that signalled shock for the subject. With no shock and at low shock intensities, where the subject's responding was not suppressed or suppressed only slightly, the co-actor had little effect. At the higher shock intensities, where the subject's responding was reduced by at least 40%, the response rate during the warning stimulus was consistently higher when the co-actor was present. One explanation of these results assumes a special relationship between social stimuli and aversive stimuli in which the presence of another animal reduces emotional reactions and thereby allows operant responses to increase. This was not the case here because the mere presence of the co-actor did not maintain social facilitation. Rather, the present results, taken in conjunction with previous findings, suggest that changes in social and non-social variables which affect the rate of food-reinforced responding may produce proportionately larger changes in responding when that responding is suppressed by aversive stimulation than when it is not.

Bone ingrowth into porous silicon nitride

Achieving solid skeletal attachment is a requirement for the clinical success of orthopedic implants. Porous or roughened surfaces and coatings have been developed and used with mixed success to achieve attachment due to bone ingrowth. Silicon nitride is a high performance ceramic whose strength, imaging properties, and biocompatibility make it a candidate material for orthopedic implants. A porous form of silicon nitride, cancellous-structured ceramic (CSC), has been developed. CSC is a nonresorbable, partially radiolucent porous structure that can be bonded to orthopedic implants made of silicon nitride to facilitate skeletal attachment. The purpose of this study was to quantify the extent and rate of bone ingrowth into CSC in a large animal model. Cylindrical implants were placed bilaterally using staged surgeries in the medial femoral condyle of six sheep. Condyles were retrieved after 3 and 6 months in situ and prepared for examination of bone growth under SEM. Bone grew into CSC to extents and at rates similar to those reported for other titanium porous surfaces in studies involving large animals and postmortem retrievals in humans. Bone ingrowth was observed at depths of penetration greater than 3 mm in some implants after only 12 weeks in situ. Bone ingrowth into CSC is a viable method for achieving skeletal attachment.

Characterization of Adducts Formed in the Reaction of Glutaraldehyde with 2‘-Deoxyadenosine

Glutaraldehyde (1,5-pentanedial) is a widely used industrial chemical that has been found to be mutagenic in bacteria and mammalian cells. In this study, we examined the reaction of glutaraldehyde with 2'-deoxyadenosine and calf thymus DNA in aqueous buffered solutions. The 2'-deoxyadenosine adducts were isolated by reversed phase HPLC and characterized by their UV absorbance and 1H and 13C NMR spectroscopic and mass spectrometric features. The reaction produced three major adducts. The adduct dA567 was derived from two 2'-deoxyadenosine units bound together with a piperidine unit, and its yield was 10.4%. The carbons of the piperidine ring originated from glutaraldehyde, whereas the nitrogen of the ring originated from the exocyclic amino group of one of the 2'-deoxyadenosine units. The adduct dA451d (yield 0.6%) was similar in structure to dA567, but one of the deoxyribose moieties from 2'-deoxyadenosine was missing. The third adduct, dA334, consisted of a hydroxy-tetrahydropyridine moiety derived from glutaraldehyde and N6 of 2'-deoxyadenosine (yield 4.0%). Furthermore, LC-ESI-MS/MS analysis of the reaction mixture revealed the formation of compounds with ion peaks of m/z = 352. None of these compounds were sufficiently stable for preparative isolation. They were tentatively identified as a pair of diastereomers of 2,6-dihydroxypiperidine derivatives, which are likely precursors to dA334. Plausible mechanisms for the formation of the adducts are presented. In the reaction of glutaraldehyde with single and double stranded calf thymus DNA, the dA334 adduct was formed.

Glomerular apoptotic nucleosomes are central target structures for nephritogenic antibodies in human SLE nephritis

Antibodies to double-stranded (dsDNA) are associated with systemic lupus erythematosus (SLE) and directly involved in human lupus nephritis. Information about their glomerular target antigens is inconsistent, and whether availability of target antigens, antibody specificity or avidity are nephritogenic parameters, is not determined. In this study, we analyzed renal tissue from anti-dsDNA antibody-positive lupus patients with nephritis by morphological and immunological assays, including immune electron microscopy (IEM) and colocalization IEM, an EM-based confocal microscopy assay. IEM demonstrated that antibody deposits were confined to electron dense structures (EDS) in glomerular membranes. These autoantibodies colocalized with nucleosome-binding anti-dsDNA/-histone/-transcription factor antibodies. To confirm the colocalization IEM-data, we developed a colocalization terminal deoxynucleotidyl-transferase (TdT) biotin-dUTP nicked end-labeled (TUNEL) IEM assay where extracellular DNA was traced by TdT-mediated introduction of biotinylated nucleotides and autoantibodies by IEM. Results consistently demonstrated that DNA colocalized with autoantibodies in glomerular membrane-associated EDS. The colocalization IEM and colocalization TUNEL IEM assays thus demonstrate that intra-glomerular membrane-associated nucleosomes are targeted by anti-dsDNA autoantibodies in human lupus nephritis. The data provide a new approach to understand basic molecular and immunological processes accounting for antibody-mediated nephritis in human SLE.

Determination of the dialdehyde glyoxal in workroom air—development of personal sampling methodology

The dialdehyde glyoxal (ethanedial) is an increasingly used industrial chemical with potential occupational health risks. This study describes the development of a personal sampling methodology for the determination of glyoxal in workroom air. Among the compounds evaluated as derivatizing agents; N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH), 1,2-phenylenediamine (OPDA), 1-dimethylaminonaphthalene-5-sulfonylhydrazine (dansylhydrazine, DNSH) and 2,4-dinitrophenylhydrazine (DNPH), DNPH was the only reagent that was suitable. Several different samplers were evaluated for sampling efficiency of glyoxal in workroom air using DNPH as derivatizing agent; in-house DNPH coated silica particles packed in two different types of glass tubes, impingers containing acidified DNPH solution, filter cassettes containing glass fibre filters coated with DNPH, a commercially available solid phase cartridge sampler originally developed for formaldehyde sampling (Waters Sep-Pak DNPH-silica cartridge), and the commercially available SKC UMEx 100 passive sampler originally developed for formaldehyde sampling. Aldehyde atmospheres for sampler evaluation were generated with an in-house made vapour atmosphere generator coupled to a sampling unit, with the possibility of parallel sampling. The resulting glyoxal-DNPH derivative was determined using both LC-UV and LC-APCI-MS with negative ionization. By far, the highest recovery of glyoxal was obtained employing one of the in-house DNPH coated silica samplers (93%, RSD = 3.6%, n = 12).

Epimerization and stability of two new cis-benzo[a]pyrene tetrols by the use of liquid chromatography-fluorescence and mass spectrometry

Quantitative determination of the hydrolysis products from proteins and DNA gives valuable information regarding the reactive metabolite that forms the protein and DNA adduct. Quantification of protein-benzo[a]pyrene (BP) adducts represents a more sensitive method than quantification of BP-DNA adducts. The aim of the present study was to identify two hydrolysis products from BP-derived protein adducts found in vitro and in vivo in a previous study. Male Wistar rats were injected i.p. with BP, and serum albumin was isolated and subjected to acid hydrolysis at 70 degrees C for 3 h. The hydrolysate was subjected to LC separation, and fractions of the two unknown compounds were collected. The molecular masses of the two unknown compounds were in accordance with being tetrols as judged by LC electrospray mass spectrometry. The fragmentation patterns were characteristic of tetrols with formation of the molecular ion and the loss of water molecules. In addition, the compounds were subjected to acid hydrolysis at 70 degrees C with 0.1 M HCl for 3 h. We observed that two of the known tetrols epimerized to the two unknown tetrols and vice versa. This is probably a characteristic epimerization involving not only position C(10)-OH but also another site like position C(7)-OH. The in vivo findings of the two unknown adducts are probably the result of the formation of BPDE III in the metabolism of BP. These two tetrols must then have the C(7)-OH and C(8)-OH groups in a cis position.

Cross shift changes in lung function among bar and restaurant workers before and after implementation of a smoking ban

OBJECTIVE

To study possible cross shift effects of environmental tobacco smoke (ETS) on pulmonary function among bar and restaurant employees before and after the implementation of a smoking ban in Norway.

METHODS

The study included 93 subjects employed in 13 different establishments in Oslo. They were examined at the beginning and end of a workshift both while ETS exposure was present and when smoking was banned. The mean exposure level of nicotine and total dust before the ban was 28 microg/m3 (range 3-65) and 275 microg/m3 (range 81-506), respectively. Following the smoking ban, the mean level of nicotine and total dust was 0.6 mug/m3 and 77 microg/m3, respectively. Assessment of lung function included dynamic lung volumes and flows.

RESULTS

The cross shift reduction in forced vital capacity (FVC) among 69 subjects participating in both examinations changed from 81 ml (SD 136) during exposure to ETS to 52 ml (SD 156) (p = 0.24) following the smoking ban. The reduction in forced expired volume in one second (FEV1) during a workshift, was borderline significantly reduced when comparing the situation before and after the intervention, by 89 ml (SD = 132) compared to 46 ml (SD = 152) (p = 0.09), respectively. The reduction in forced mid-expiratory flow rate (FEF25-75%) changed significantly from 199 ml/s (SD = 372) to 64 ml/s (SD = 307) (p = 0.01). Among 26 non-smokers and 11 asthmatics, the reduction in FEV1 and FEF25-75% was significantly larger during ETS exposure compared to after the smoking ban. There was an association between the dust concentration and decrease in FEF25-75% before the ban among non-smokers (p = 0.048).

CONCLUSIONS

This first study of cross shift changes before and after the implementation of a smoking ban in restaurants and bars shows a larger cross shift decrease in lung function before compared with after the implementation of the ban.

Hand tremor related to smoking habits and the consumption of caffeine in male industrial workers

Tremor was measured in 49 smokers/snuffers and in 49 non-smokers/non-snuffers in a cross-sectional study. The Kløve-Matthews static steadiness test and TREMOR 7.0 from the CATSYS test system were used to assess the hand tremor. The creatinine (cr) corrected arithmetic mean concentrations of cotinine in urine were 11 microg/g cr (range 0.1-430) in the non-smokers/non-snuffers compared to 1,417 microg/g cr (range 45-3,780) in the smokers/snuffers. The geometric mean urinary caffeine concentrations were 797 microg/g cr (range 0.5-13,330) in the non-smokers/non-snuffers versus 654 microg/g cr (range 0.9-7,470) in the smokers/snuffers. Increased tremor was found in the group of smokers/snuffers compared to the non-smokers/non-snuffers for several parameters on the tremor measurements, e.g. geometric mean tremor intensity of 0.14 m/s(2) (range 0.09-0.40) in the smokers/snuffers versus 0.11 m/s(2) (range 0.07-0.22) in the non-smokers/non-snuffers for the dominant hand were quantified. Also the mean scores on the static steadiness test were inferior in the smokers/snuffers, in particular for the number of touches. The results further indicate that the frequency dispersion is smaller in the smokers/snuffers compared to the non-smokers/non-snuffers. No systematic association was observed between the biomarkers of nicotine and caffeine exposure and the tremor measurements. However, older age appeared to be an important predictor for the magnitude of tremor in the smokers/snuffers, but not in the non-smokers/non-snuffers.