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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. [ABSTRACT FROM AUTHOR]

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 functionmeasurements. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Aerosolization of components when processing king crab (Paralithodes camtschaticus) and edible crab ( Cancerpagurus) 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-β-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 2.5 ng m-3 during cooked processing. Conversely, edible crab tropomyosin levels were highest during cooked processing with GM 45.4 versus 8.7 ng 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-methylumbellifer-one (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, endo-toxins, trypsin, and NAGase in their breathing zone. Levels vary between worker groups and factories. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated low percentage of HL-60 cell differentiation with theophylline. The present study demonstrate that millimolar concentrations of the non-selective phosphodiesterase inhibitors theophylline, caffeine and isobutyl-methylxanthine all inhibit growth, induce substantial differentiation and elevation of both cAMP and cGMP in HL-60 cells. Selective inhibition of CAMP hydrolysis by Ro20-1724 was without effect. The guanylate cyclase stimulator sodium nitroprusside, which increased cGMP only poorly and also increased CAMP, produced growth inhibition but no differentiation. We put forward the hypothesis that elevation of both cAMP and cGMP above a critical level is necessary for significant cyclic nucleotide induced HL-60 cell differentiation. [ABSTRACT FROM AUTHOR]