Occupational asthma in the salmon processing industry: a case series.

OBJECTIVES: Exposure to bioaerosols in salmon processing workers is associated with occupational asthma. IgE-mediated allergy and other disease mechanisms may be involved in airway inflammation and obstruction. Knowledge about disease burden, mechanisms, phenotypes and occupational exposure is limited. METHODS: Salmon processing workers referred to our occupational medicine clinic from 2019 to 2024 were included in a patient register. They were investigated in line with current guidelines for the management of occupational asthma, categorised according to diagnostic certainty and characterised with a focus on symptoms, work tasks and clinical findings. RESULTS: A total of 36 patients were included, among whom 27 had typical symptoms of work-related asthma, and 21 were diagnosed with occupational asthma. Among those with occupational asthma, all worked in the filleting or slaughtering area at the time of symptom onset. Median latency from the start of exposure to symptom onset was 4 years. 14 (67%) of the patients with occupational asthma were sensitised to salmon. Three patients were sensitised to salmon skin but not salmon meat. CONCLUSIONS: Occupational asthma among salmon processing workers displays a heterogeneous clinical picture. IgE-mediated inhalation allergy towards various parts of the salmon seems to represent an important pathophysiological mechanism. However, some have occupational asthma with negative allergy tests. A comprehensive workup strategy including early initiation of serial peak expiratory flow and skin prick tests with various parts of the salmon should be considered. Although the incidence remains unknown, the substantial number of cases presented warrant increased efforts to reduce harmful exposure in the salmon processing industry.

Airborne bacterial and fungal species in workstations of salmon processing plants.

Significant quantities of salmon are processed daily in the industry's indoor facilities. Occupational exposure contributes to an individual's exposome. The aim of this study is to obtain knowledge about potential exposure to viable airborne species of bacteria and fungi as related to workstations in the salmon processing industry. The study was conducted in nine salmon plants along the Norwegian coast over one or two days with a one-year interval. The MAS100 was used for sampling and MALDI-TOF MS for species identification. The geometric mean concentrations of bacteria and fungi were 200 CFU/m3 and 50 CFU/m3, respectively, with the highest concentrations of bacteria found in slaughtering areas and fungi in trimming of fillets. In total 125 gram-negative and 90 gram-positive bacterial and 32 different fungal species were identified. Some genera were represented by several species e.g. Chryseobacterium (15 species), Flavobacterium (13 species), Microbacterium (12 species), Pseudomonas (37 species), and Psychrobacter (13 species). Risk class 2 (RC2, human pathogens) were found in all types of workstations and plants. Seventeen bacterial species belong to RC2, some were fish pathogens, food spoilage bacteria, or species causing foodborne disease. Among fungi, Aspergillus nidulans was frequently detected across different workstations and plants. In conclusion, bacterial and fungal concentrations were low. Fish and sea-related bacteria were found along the salmon processing line. Bacterial concentrations and species compositions differ between workstations. No particular bacterial or fungal species constituted a large fraction of all airborne species. Based on the presence of human pathogens, using protective gloves is important for the workers. The presence of human and fish pathogens and food spoilage bacteria reveals air as a transmission route for bacteria, potentially affecting workers, consumers, fish, and hygiene of processing equipment. To limit the spread of these bacteria an interdisciplinary cooperation with a One Health perspective may be relevant.

Effects of Interventions to Prevent Work-Related Asthma, Allergy, and Other Hypersensitivity Reactions in Norwegian Salmon Industry Workers (SHInE): Protocol for a Pragmatic Allocated Intervention Trial and Related Substudies.

BACKGROUND: Workers in the salmon processing industry have an increased risk of developing respiratory diseases and other hypersensitivity responses due to occupational exposure to bioaerosols containing fish proteins and microorganisms, and related allergens. Little is known about effective measures to reduce bioaerosol exposure and about the extent of skin complaints among workers. In addition, while identification of risk factors is a core activity in disease prevention strategies, there is increasing interest in health-promoting factors, which is an understudied area in the salmon processing industry. OBJECTIVE: The overall aim of this ongoing study is to generate knowledge that can be used in tailored prevention of development or chronification of respiratory diseases, skin reactions, protein contact dermatitis, and allergy among salmon processing workers. The main objective is to identify effective methods to reduce bioaerosol exposure. Further objectives are to identify and characterize clinically relevant exposure agents, identify determinants of exposure, measure prevalence of work-related symptoms and disease, and identify health-promoting factors of the psychosocial work environment. METHODS: Data are collected during field studies in 9 salmon processing plants along the Norwegian coastline. Data collection comprises exposure measurements, health examinations, and questionnaires. A wide range of laboratory analyses will be used for further analysis and characterization of exposure agents. Suitable statistical analysis will be applied to the various outcomes of this comprehensive study. RESULTS: Data collection started in September 2021 and was anticipated to be completed by March 2023, but was delayed due to the COVID-19 pandemic. Baseline data from all 9 plants included 673 participants for the health examinations and a total of 869 personal exposure measurements. A total of 740 workers answered the study's main questionnaire on demographics, job characteristics, lifestyle, health, and health-promoting factors. Follow-up data collection is not completed yet. CONCLUSIONS: This study will contribute to filling knowledge gaps concerning salmon workers' work environment. This includes effective workplace measures for bioaerosol exposure reduction, increased knowledge on hypersensitivity, allergy, respiratory and dermal health, as well as health-promoting workplace factors. Together this will give a basis for improving the work environment, preventing occupational health-related diseases, and developing occupational exposure limits, which in turn will benefit employees, employers, occupational health services, researchers, clinicians, decision makers, and other stakeholders. TRIAL REGISTRATION: ClinicalTrials.gov NCT05039229; https://www.clinicaltrials.gov/study/NCT05039229. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48790.

Exposure to Bioaerosols During Fish Processing on Board Norwegian Fishing Trawlers.

OBJECTIVES: The main objective was to gain more knowledge on exposure to bioaerosols in the processing area on board fishing trawlers. METHODS: Exposure sampling was carried out during the work shifts when processing fish in the processing area on board five deep-sea fishing trawlers (trawlers 1-5). Exposure samples were collected from 64 fishermen breathing zone and from stationary sampling stations on board five deep-sea fishing trawlers (1-5). Trawlers 2, 3, and 4 were old ships, not originally built for on board processing of the catch. Trawlers 1 and 5 were relatively new and built to accommodate processing machineries. On trawlers 1-4 round fish was produced; the head and entrails were removed before the fishes were frozen in blocks. Trawler 5 had the most extensive processing, producing fish fillets. Samples were analysed for total protein, trypsin activity, parvalbumin, and endotoxin. One side analysis of variance and Kruskal-Wallis H test were used to compare levels of exposure on the different trawlers. RESULTS: Personal exposure to total protein were higher on the three oldest trawlers (2, 3, and 4) compared with the two new trawlers (1 and 5). Highest activity of trypsin was detected on the four trawlers producing round fish (1-4). Parvalbumin was detected in 58% of samples from the fillet-trawler (5) compared with 13% of samples from the four trawlers producing round fish. The highest level of endotoxin was detected when using high-pressure water during cleaning machines and floors in the processing area. CONCLUSIONS: Fishermen in the processing area on board Norwegian trawlers are exposed to airborne bioaerosols as proteins, trypsin, fish allergen parvalbumin, and endotoxin. Levels varied between trawlers and type of production.

Occupational Allergic Sensitization Among Workers Processing King Crab (Paralithodes camtschaticus) and Edible Crab (Cancer pagurus) in Norway and Identification of Novel Putative Allergenic Proteins.

Introduction: Asthma and allergy occur frequently among seafood processing workers, with the highest prevalence seen in the crustacean processing industry. In this study we established for the first time the prevalence of allergic sensitization in the Norwegian king- and edible crab processing industry and characterized the IgE-reactive proteins. Materials and Methods: Two populations of crab processing workers participated; 119 king crab and 65 edible crab workers. The investigation included information on work tasks and health through a detailed questionnaire. Allergic sensitization was investigated by crab-specific IgE quantification and skin prick tests (SPT) to four in-house prepared crab extracts; raw meat, cooked meat, raw intestines and raw shell. Allergen-specific IgE binding patterns were analyzed by IgE immunoblotting to the four allergen extracts using worker serum samples. Total proteins in crab SPT extracts and immunoblot-based IgE binding proteins were identified by mass spectrometric analysis. Results: Positive SPTs were established in 17.5% of king- and 18.1% of edible crab workers, while elevated IgE to crab were demonstrated in 8.9% of king- and 12.2% of edible crab processing workers. There was no significant difference between the king and edible crab workers with respect to self-reported respiratory symptoms, elevated specific IgE to crab or SPT results. Individual workers exhibited differential IgE binding patterns to different crab extracts, with most frequent binding to tropomyosin and arginine kinase and two novel IgE binding proteins, hemocyanin and enolase, identified as king- and edible crab allergens. Conclusions: Occupational exposure to king- and edible crabs may frequently cause IgE mediated allergic sensitization. Future investigations addressing the diagnostic value of crab allergens including tropomyosin and arginine kinase and the less well-known IgE-binding proteins hemocyanin and enolase in a component-resolved diagnostic approach to crab allergy should be encouraged.

Exposures and Health Effects of Bioaerosols in Seafood Processing Workers - a Position Statement.

Occupational hazards exist in the processing of seafood both in land-based facilities as well as on board vessels. Recent findings on occupational injury and respiratory health risks among seafood processing workers were presented and discussed at the IFISH5 conference. Particular emphasis was put on the challenges that im/migrant workers encounter, the greater risks onboard factory vessels, especially where processing machinery are retrofitted to older vessels not primarily designed for this purpose, and the difficulties in assessing and preventing bioaerosol exposures and associated respiratory health risks despite recent advances in characterising agents responsible for allergic and non-allergic reactions. Based on appraisal of existing knowledge in the published literature and new findings presented at the conference, recommendations for immediate actions as well as for future research have been proposed. Among these include the importance of improving extraction ventilation systems, optimising machinery performance, enclosure of bioaerosol sources, improved work organization, and making special efforts to identify and support the needs of im/migrant workers to ensure they also benefit from such improvements. There is a need for studies that incorporate longitudinal study designs, have improved exposure and diagnostic methods, and that address seafood processing in countries with high seafood processing activities such as Asia and those that involve im/migrant workers worldwide. The medical and scientific community has an important role to play in prevention but cannot do this in isolation and should cooperate closely with hygienists, engineers, and national and international agencies to obtain better health outcomes for workers in the seafood industry.

Airborne exposure to gaseous and particle-associated organic substances in resin-based dental materials during restorative procedures.

Dental composite dust has been shown to act as a vehicle for methacrylates in vivo/in vitro. The objective of this study was to assess airborne exposure of dental personnel to gaseous and particle-associated organic constituents from resin-based dental materials in a simulated clinic. Sampling of total aerosol fractions and gaseous substances was performed by dental students carrying particle filters and gas sorbents attached to a personal pump during preclinical restorative procedures in phantom models (n = 13). Water from the phantoms was sampled. Organic substances were extracted from the sampled water, particle filters, and gas sorbents. Qualitative and quantitative analyses were performed by gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). The methacrylates 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA) and the additives camphorquinone (CQ), butylated hydroxytoluene (BHT), and ethyl 4-(dimethylamino)benzoate (DMABEE), were quantified in the gas and particle fractions sampled. A positive-control experiment was conducted. No methacrylates were detected in the gas or particle fractions sampled, whereas strong signals for methacrylates were detected in the positive controls, matching the analysis of the uncured material. In addition, TEGDMA and DMABEE were quantified in the sampled water. Airborne exposure to constituents in resin-based dental materials was below the detection limit. However, the extent of exposure is probably dependent on the procedure, preventive measures, and type of materials used.

Food processing and occupational respiratory allergy- An EAACI position paper.

Occupational exposure to foods is responsible for up to 25% of cases of occupational asthma and rhinitis. Animal and vegetable high-molecular-weight proteins present in aerosolized foods during food processing, additives, preservatives, antioxidants, and food contaminants are the main inhalant allergen sources. Most agents typically cause IgE-mediated allergic reactions, causing a distinct form of food allergy (Class 3 food allergy). The allergenicity of a food protein, allergen exposure levels, and atopy are important risk factors. Diagnosis relies on a thorough medical and occupational history, functional assessment, assessment of sensitization, including component-resolved diagnostics where appropriate, and in selected cases specific inhalation tests. Exposure assessment, including allergen determination, is a cornerstone for establishing preventive measures. Management includes allergen exposure avoidance or reduction (second best option), pharmacological treatment, assessment of impairment, and worker's compensation. Further studies are needed to identify and characterize major food allergens and define occupational exposure limits, evaluate the relative contribution of respiratory versus cutaneous sensitization to food antigens, evaluate the role of raw versus cooked food in influencing risk, and define the absolute or relative contraindication of patients with ingestion-related food allergy, pollinosis, or oral allergy syndrome continuing to work with exposure to aerosolized food allergens.

A Sensitive Assay for Proteases in Bioaerosol Samples: Characterization and Quantification of Airborne Proteases in Salmon Industry Work Environments.

Proteases are probably underestimated exposure agents in bioaerosols. Their roles as barrier disrupters in allergic sensitization and activators of innate inflammation call for more attention in exposure-response studies. The main objectives of this study was (i) to establish a suitable method for detection of small quantities of proteases in filtered air samples and (ii) to utilize the method to characterize exposure to proteases in a salmon industry work environment. Analysis of proteases in filtered air samples was based on zymography, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 0.1% gelatin as substrate added in the polyacrylamide gel. Gelatinase activity was evident as cleared (unstained) regions. The area of these regions was quantified using image analysis (UVP Vision Works®). Standard curves with known amounts of active porcine trypsin were added to each gel. Validation of 11 non-linear standard curves showed R2 (range) = 0.8989-0.9882, limit of detection = 0.056 nM, lower limit of quantification = 0.161 nM, and coefficients of variations (range) = 20-28%. Sampling of bioaerosols in salmon industry was performed using polytetrafluoretylene filters with an airflow of 3 l min-1. All samples contained visible bands close to the size of porcine trypsin (23.3 kDa). The bands did not disappear in the presence of EDTA but abolished by Pefabloc, demonstrating that the enzyme is a serine protease, most likely salmon trypsin. Airborne levels of active protease were below the statistical detection limit in the filleting department but quantifiable in extract samples from the slaughter department. Three filtered air samples from the slaughter department showed air concentrations of 6.2, 16.5, and 27.0 ng m-3 air. We conclude that zymography is a sensitive and reliable method for exposure assessment of active proteases in indoor environmental samples. We recommend this assay for use in occupational studies to characterize and quantify exposure to active proteases in bioaerosols.

Lung function and prevalence of respiratory symptoms in Norwegian crab processing workers.

BACKGROUND: Seafood processing workers have an increased risk of developing occupational asthma. This has not been studied among Norwegian crab processing workers, nor has the respiratory health of exposed workers been compared to a control group. OBJECTIVES: Assessing the impact of working in the crab processing industry on workers' respiratory health. DESIGN: A cross-sectional study of the respiratory health in two types of crab processing workers compared to a control group. METHODS: The study included 148 king crab (Paralithodes camtschaticus) workers, 70 edible crab (Cancer pagurus) workers and 215 controls. Workers answered a questionnaire and performed spirometry measurements. χ2 and Fishers exact tests were performed on self-reported respiratory symptoms. Regression analyses and t-tests were used to assess lung function values. RESULTS: Self-reported respiratory symptoms were higher among crab processing workers compared to controls, and higher among king crab workers compared to edible crab workers. There was no significant difference between crab processing workers and controls in lung function measurements. Self-reported doctor-diagnosed asthma prevalence was highest in the control group. CONCLUSIONS: Increased respiratory symptoms reported by crab processing workers were not reflected in impaired lung function values or asthma diagnose. We suggest a healthy worker effect among crab processing workers in Norway.

Occupational Exposure to Bioaerosols in Norwegian Crab Processing Plants.

INTRODUCTION: Aerosolization of components when processing king crab (Paralithodes camtschaticus) and edible crab (Cancer pagurus) may cause occupational health problems when inhaled by workers. METHODS: A cross-sectional study was carried out in three king crab plants and one edible crab plant. Personal exposure measurements were performed throughout work shifts. Air was collected for measurement of tropomyosin, total protein, endotoxin, trypsin, and N-acetyl-ß-d-glucosaminidase (NAGase). T-tests and ANOVAs were used to compare the levels of exposure in the different plants and areas in the plants. RESULTS: Total protein and tropomyosin levels were highest in the edible crab plant, endotoxin levels were highest in king crab plants. King crab exposure levels were highest during raw processing. Tropomyosin levels were highest during raw king crab processing with geometric mean (GM) 9.6 versus 2.5ng m(-3) during cooked processing. Conversely, edible crab tropomyosin levels were highest during cooked processing with GM 45.4 versus 8.7ng m(-3) during raw processing. Endotoxin levels were higher in king crab plants than in the edible crab plant with GM = 6285.5 endotoxin units (EU) m(-3) versus 72 EU m(-3). In the edible crab plant, NAGase levels were highest during raw processing with GM = 853 pmol4-methylumbelliferone (MU) m(-3) versus 422 pmol4-MU m(-3) during cooked processing. Trypsin activity was found in both king crab and edible crab plants and levels were higher in raw than cooked processing. Differences in exposure levels between plants and worker groups (raw and cooked processing) were identified. CONCLUSIONS: Norwegian crab processing workers are exposed to airborne proteins, tropomyosin, endotoxins, trypsin, and NAGase in their breathing zone. Levels vary between worker groups and factories.

Mixed exposure to bacterial lipopolysaccharide and seafood proteases augments inflammatory signalling in an airway epithelial cell model (A549).

Seafood industry workers exhibit increased prevalence of respiratory symptoms due to exposure to bioaerosols containing a mixture of bioactive agents. In this study, a human pulmonary epithelial cell model (A549) was exposed to mixtures of bacterial lipopolysaccharide (LPS) and protease-activated receptor-2 (PAR-2) agonists H-Ser-Leu-Ile-Gly-Lys-Val-NH2 (SLIGKV-NH2), purified salmon ( Salmo salar) trypsin or purified king crab ( Paralithodes camtschaticus) trypsin. The inflammatory response was measured based on nuclear factor-kappa B (NF-κB) activation of transcription in a luciferase reporter gene assay and interleukin 8 (IL-8) secretion in an enzyme-linked immunosorbent assay. We observed that mixtures of SLIGKV-NH2 or trypsins with LPS augmented the activation of NF-κB and secretion of IL-8. The effect on IL-8 secretion was synergistic when both trypsins and LPS were used in the lower concentration range. The results demonstrate that exposure to mixtures of agents that are relevant to seafood industry workplaces may lead to increased inflammatory signalling compared with exposure to the individual agents alone. Furthermore, the results indicate that synergism may occur with the combined exposure to seafood trypsins and LPS and is most likely to occur when exposure to either agent is low.

Respiratory symptoms, lung functions, and exhaled nitric oxide (FENO) in two types of fish processing workers: Russian trawler fishermen and Norwegian salmon industry workers.

OBJECTIVE: Respiratory outcomes and work-related factors were studied in two seafood worker populations representing different occupational environments. METHODS: Levels of fractional exhaled nitric oxide (FENO), spirometric values, prevalence of respiratory symptoms, and self-evaluated exposures were compared between 139 Norwegian salmon workers and 127 Russian trawler workers. RESULTS: Increased odds ratios (ORs) of shortness of breath with wheezing and prolonged cough as general respiratory symptoms were found in salmon workers, while increased ORs of work-related dry cough and running nose were found in trawler fishermen. Both worker groups ranked "cold work environment," "use of disinfectants," and "contaminated indoor air" as the first, second, and third most important causes of work-related respiratory symptoms, respectively. Fractional exhaled nitric oxide levels were higher in asthmatic trawler workers compared to asthmatic salmon workers. CONCLUSIONS: Respiratory symptoms commonly associated with obstructive airway diseases were more prevalent in salmon workers, while symptoms commonly associated with asthma and short-term effects of cold air exposure were more prevalent in trawler workers.

Salmon and king crab trypsin stimulate interleukin-8 and matrix metalloproteinases via protease-activated receptor-2 in the skin keratinocytic HaCaT cell line.

Occupational skin symptoms are prevalent among the workers of the seafood processing industry. In this study we investigate the role of salmon (Salmo salar) and king crab trypsin (Paralithodes camtschaticus) as inducers of inflammation in skin via secretion of inflammatory mediators. Human skin keratinocytes (HaCaT cells) were exposed to purified salmon and king crab trypsin. We observed that salmon trypsin enhanced the secretion of IL-8 and MMP-2 and crab trypsin enhanced the secretion of IL-8, MMP-2 and MMP-9 in a dose dependent manner. As protease activated receptors (PAR)-2 in skin are known to play an important role in physiology and pathology, we explored the involvement of these receptors in mediating the release of interleukin (IL)-8 and matrix metalloproteinase (MMP)-2 and -9 subsequent to exposure of skin keratinocytes to salmon and crab trypsin. In addition we observed that salmon and crab trypsin exhibit individual differences in stimulating the release of these inflammatory mediators. Finally, using specific small interfering RNA (siRNA) against PAR-2, we confirmed that the increase in secretion of IL-8, MMP-2 and MMP-9 in skin keratinocytes following exposure to salmon and crab trypsin was mediated via activation of PAR-2. These results suggest that exposure to proteases from the seafood may lead to inflammatory reactions in skin.

Molecular and immunological approaches in quantifying the air-borne food allergen tropomyosin in crab processing facilities.

Tropomyosin is a cross-reactive allergenic protein present in ingested shellfish species. Exposure and sensitization to this protein via inhalation is particularly important in the crustacean processing industry where workers are continuously exposed to the aerosolized form of this allergen. The aim of this study was to develop an antibody-based immunoassay to enable the specific and sensitive quantification of aerosolized tropomyosin present in the environment of two crab processing facilities. Anti-tropomyosin antibody was generated in rabbits against tropomyosins from four different crustacean species. These antibodies were purified using recombinant tropomyosin using an immuno-affinity column. The recombinant tropomyosin was also used as an allergen standard for the sandwich ELISA. In order to quantify aerosolized tropomyosin, air collection was performed in the personal breathing zone of 80 workers during two crab processing activities, edible crab (Cancer pagurus) and king crab (Paralithodes camtschaticus) using polytetrafluoroethylene filters. The purified antibody was able to detect tropomyosin selectively from different crustaceans but not from vertebrate sources. The limit of detection (LOD) for the developed sandwich ELISA was 60 picogram/m(3) and limit of quantitation (LOQ) 100 picogram/m(3). Immunoassay validation was based on linearity (R(2) 0.999), matrix interference test (78.8±6.5%), intra-assay CV (9.8%) and inter-assay CV (11%). The novel immunoassay was able to successfully identify working activities, which generated low, medium or high concentrations of the aerosolized food allergen. We describe an IgG antibody-based immunoassay for quantification of the major food allergen tropomyosin, with high sensitivity and specificity. This modified immunological approach can be adapted for the detection of other aerosolized food allergens, assisting in the identification of high-risk allergen exposure areas in the food industry.

Respiratory effects of bioaerosols: exposure-response study among salmon-processing workers.

OBJECTIVES: The aim of the study was to determine exposure-response relationships in salmon-processing workers. METHODS: Cross-shift FEV1, acute respiratory symptoms, and exposure to total protein, parvalbumin and endotoxin were main variables measured during one workweek. Exposure-response relationships were analyzed by Generalized Estimation Equations of cross-week data and by multiple regressions of day-to-day data. RESULTS: Exposure levels were higher in those workers who reported use of water hose. GEE showed negative coefficients for interaction between TP exposure and time (days) on cross-week change of FEV1. Multiple regressions showed significant associations between TP levels and cross-shift change of FEV1 and symptoms (cough, chest tightness) only for Monday shifts. CONCLUSIONS: A tolerance effect during the course of a workweek is suggested. Use of water hose is a risk process with regard to the liberation of measured components of bioaerosols.

Differences in PAR-2 activating potential by king crab (Paralithodes camtschaticus), salmon (Salmo salar), and bovine (Bos taurus) trypsin.

BACKGROUND: Salmon trypsin is shown to increase secretion of the pro-inflammatory cytokine interleukin (IL)-8 from human airway epithelial cells through activation of PAR-2. Secretion of IL-8 induced by king crab trypsin is observed in a different concentration range compared to salmon trypsin, and seems to be only partially related to PAR-2 activation. This report aim to identify differences in the molecular structure of king crab trypsin (Paralithodes camtschaticus) compared to salmon (Salmo salar) and bovine trypsin (Bos taurus) that might influence the ability to activate protease-activated receptor-2 (PAR-2). RESULTS: During purification king crab trypsin displayed stronger binding capacity to the anionic column used in fast protein liquid chromatography compared to fish trypsins, and was identified as a slightly bigger molecule. Measurements of enzymatic activity yielded no obvious differences between the trypsins tested. Molecular modelling showed that king crab trypsin has a large area with strong negative electrostatic potential compared to the smaller negative areas in bovine and salmon trypsins. Bovine and salmon trypsins also displayed areas with strong positive electrostatic potential, a feature lacking in the king crab trypsin. Furthermore we have identified 3 divergent positions (Asp196, Arg244, and Tyr247) located near the substrate binding pocket of king crab trypsin that might affect the binding and cleavage of PAR-2. CONCLUSION: These preliminary results indicate that electrostatic interactions could be of importance in binding, cleavage and subsequent activation of PAR-2.

An analysis of the respiratory health status among seafarers in the Russian trawler and merchant fleets.

OBJECTIVES: Trawler fishermen and merchant seafarers have tough working conditions. While workers in both occupations are exposed to a challenging environment, trawler fishermen are also engaged in onboard fish processing, which is considered to be additional exposure. The aim of the present study was to characterize respiratory health status in both groups of seamen. METHODS: In total 127 trawler fishermen and 118 merchant seafarers were enrolled during their regular medical health examinations. The study protocol comprised a standardized questionnaire, lung function test and measurements of fractional nitric oxide concentrations (FE(NO) ) in exhaled air. RESULTS: Doctor-diagnosed asthma was reported only by trawler fishermen (3.9%, P < 0.05, Pearson Chi-square test). Adjusted odds ratios (OR) of respiratory symptoms were more often elevated in trawler fishermen compared to merchant seafarers. Trawler fishermen had reduced spirometric parameters: FEV(1) % of predicted values (adjusted ß: -5.28, 95%CI: -9.28 to -1.27), FVC % of predicted values (adjusted ß: -5.21, 95%CI: -9.25 to -1.17). Increased OR of the work-related cough with phlegm (OR: 6.6, 95% CI: 1.8-21.9), running nose (OR: 3.0, 95%CI: 1.2-7.7), and frequent sneezing (OR: 3.4, 95%CI: 1.0-12.7) were found among those trawler workers whose work tasks included filleting of fish. FE(NO) levels were not significantly different between trawler and merchant seamen. CONCLUSIONS: The present study indicated that trawler fishermen exhibited impaired lung function and were more likely to have asthma. The environment of the onboard factories where fishermen fillet fish is suggested as a risk factor for work-related respiratory symptoms.

Respiratory impairment in Norwegian salmon industry workers: a cross-sectional study.

OBJECTIVES: The aim of this study was to assess the respiratory status in salmon-processing workers. METHODS: The study population was composed of 139 salmon workers and 214 controls. A study protocol comprised a questionnaire, spirometry, measurements of fractional exhaled nitric oxide concentration, and total and specific immunoglobulin E analyses. RESULTS: Adjusted odds ratio of general respiratory symptoms ranged from 2.2 for wheezing to 3.6 for daily morning cough. Salmon workers were found to have an excess of work-related respiratory symptoms (2.9 ≤ adjusted odds ratio ≤ 13.6) and reduced lung function. Positive interaction of smoking and exposure was found for work-related upper respiratory symptoms and shortness of breath. Fractional exhaled nitric oxide concentration levels were higher in controls. None from the controls had salmon-specific immunoglobulin E, compared with 2.2% of salmon workers. CONCLUSIONS: Salmon-processing workers exhibit impaired respiratory status and are more likely to be sensitized to salmon.

Proteases from salmon stimulate IL-8 in airway epithelial cells.

In this study the ability of salmon tissue extracts to stimulate interleukin 8 (IL-8) production in airway epithelial cells (A549) was investigated; in particular, the role of serine protease enzymes and endotoxin was examined with respect to IL-8-stimulating ability. A549 cells were stimulated by various concentrations of fish tissue extracts for 6 h. Parallel samples were incubated with a protease inhibitor cocktail, a serine protease inhibitor, or an endotoxin inhibitor. The amount of secreted IL-8 in the supernatant was determined by an enzyme-linked immunosorbent assay. A549 cells showed a concentration-dependent increase in IL-8 secretion after stimulation with extracts of salmon tissues. The IL-8-stimulating effect was inhibited by serine protease inhibitors but not by endotoxin inhibitors.