Sonnenschutz bei Beschäftigten im Freien. Entwicklung und Validierung von standardisierten Fragebögen für Verhalten und Wissen: Sun protection in outdoor workers ­ Development and validation of standardized questionnaires for behavior and knowledge.

BACKGROUND AND OBJECTIVES: Outdoor workers are at increased risk of developing non-melanoma skin cancer. We aimed to address the lack of validated German-language measurement instruments for outdoor workers' sun safety behavior and knowledge by compiling and validating two questionnaires. PARTICIPANTS AND METHODS: By expert consensus, items for the assessment of protective behavior (OccuSun) were compiled based on existing instruments. For knowledge, a translation of the Skin Cancer and Sun Knowledge (SCSK) scale was selected. After a pre-test, a validation study including 68 outdoor workers (62% female) was conducted in 2020. RESULTS: The retest reliability was r = 0.93 (95% confidence interval: 0.86-0.96) for the protection score and rs = 0.78 (0.67-0.86) for the knowledge score. Protective behaviors were correlated with respective diary data (0.38 ≤ rs ≤ 0.74, p < 0.001) and skin pigmentation changes (-0.23 ≥ rs ≥ -0.42, 0.007 ≤ p ≤ 0.165) but not with self-reported sunburn frequency (0.21 ≥ rs ≥ -0.04). CONCLUSIONS: Among German outdoor workers, two questionnaires for the assessment of sun protection behavior (OccuSun) and knowledge (SCSK) demonstrated good reliability. The OccuSun had generally good validity. Both instruments are fit for subsequent validation to determine their sensitivity to change.

Accurate redox state indication by in situ derivatization with N-ethylmaleimide - Profiling of transsulfuration and glutathione pathway metabolites by UPLC-MS/MS.

BACKGROUND: Reduced and oxidized glutathione play an important role for the intracellular detoxification of reactive oxygen species. The iron-dependent formation of such reactive oxygen species in conjunction with the inhibition of the redox-balancing enzyme glutathione peroxidase 4 underlie an imbalance in the cellular redox state, thereby resulting in a non-apoptotic form of cell death, defined as ferroptosis, which is relevant in several pathologies. METHODS: Here we present a rapid ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) based method providing the accurate quantification of 12 glutathione pathway metabolites after in situ derivatization with N-Ethylmaleimide (NEM). The method was validated regards linearity, recovery and accuracy as well as precision. The assay includes glutathione and its oxidized form glutathione disulfide. Furthermore, the related precursors cysteine, cystine, glutamic acid, γ-glutamylcysteine and cysteinylglycine, biomarkers of protein crosslinking such as cystathionine and lanthionine, as well as metabolites of the transsulfuration pathway, methionine, homocysteine and serine are simultaneously determined. RESULTS: Twelve glutathione pathway metabolites were simultaneously analyzed in four different human cell line extracts within a total LC run time of 5.5 min. Interday coefficients of variation (1.7 % to 12.0 %), the mean observed accuracy (100.0 % ± 5.2 %), linear quantification ranges over three orders of magnitude for all analytes and sufficient metabolite stability after NEM-derivatization demonstrate method reliability. Immediate derivatization with NEM at cell harvesting prevents autooxidation of glutathione, ensures accurate results for the GSH/GSSG redox ratio and thereby allows interpretation of cellular redox state. CONCLUSION: The described UPLC-MS/MS method provides a sensitive and selective tool for a fast and simultaneous analysis of glutathione pathway metabolites, its direct precursors and related compounds. Assay performance characteristics demonstrate the suitability of the method for applications in different cell cultures. Therefore, by providing glutathione related functional metabolic readouts, the method enables investigations in mechanisms of ferroptosis and alterations in oxidative stress levels in several pathophysiologies.

Sun protection in outdoor workers - Development and validation of standardized questionnaires for behavior and knowledge.

BACKGROUND AND OBJECTIVES: Outdoor workers are at increased risk of developing non-melanoma skin cancer. We aimed to address the lack of validated German-language measurement instruments for outdoor workers' sun safety behavior and knowledge by compiling and validating two questionnaires. PARTICIPANTS AND METHODS: By expert consensus, items for the assessment of protective behavior (OccuSun) were compiled based on existing instruments. For knowledge, a translation of the Skin Cancer and Sun Knowledge (SCSK) scale was selected. After a pre-test, a validation study including 68 outdoor workers (62% female) was conducted in 2020. RESULTS: The retest reliability was r = 0.93 (95% confidence interval: 0.86-0.96) for the protection score and rs = 0.78 (0.67-0.86) for the knowledge score. Protective behaviors were correlated with respective diary data (0.38 ≤ rs ≤ 0.74, p < 0.001) and skin pigmentation changes (-0.23 ≥ rs ≥ -0.42, 0.007 ≤ p ≤ 0.165) but not with self-reported sunburn frequency (0.21 ≥ rs ≥ -0.04). CONCLUSIONS: Among German outdoor workers, two questionnaires for the assessment of sun protection behavior (OccuSun) and knowledge (SCSK) demonstrated good reliability. The OccuSun had generally good validity. Both instruments are fit for subsequent validation to determine their sensitivity to change.

Liquid chromatography-tandem mass spectrometry based simultaneous quantification of tryptophan, serotonin and kynurenine pathway metabolites in tissues and cell culture systems.

BACKGROUND: Kynurenine and respective metabolites exhibit bioactivity as well as tryptophan, an essential amino acid, and the neurotransmitter serotonin. Dysregulations in the kynurenine pathway are involved in neurodegenerative/neuropsychiatric disorders and diabetes mellitus type 2 but also in cancer. Therefore, measurements of kynurenine-related metabolites will improve the general understanding for kynurenine pathway relevance in disease pathogenesis. METHODS: Tryptophan, serotonin, picolinic acid, quinolinic acid, 3-OH-kynurenine, kynurenine, 3-OH-anthranilic acid, kynurenic acid, anthranilic acid as well as nicotinic acid and the redox cofactor NAD+ were analyzed in heterogeneous matrices by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After validation, the described method was applied for measurements of native metabolite concentrations in murine tissues and cellular systems including pathway-shift monitoring after treatment with the tryptophan-2,3-dioxygenase-inhibitor 680C91. In addition, the method was evaluated for its ability for integration into multi-omics approaches using a single sample metabolite extraction procedure. RESULTS: A simple and sensitive UPLC-MS/MS method for simultaneous quantification of up to 10 kynurenine-related metabolites in four biological matrices was developed. Within a run time of 6.5 min, chromatographic separation of kynurenine-related metabolites, including the isomers nicotinic acid and picolinic acid, was achieved without derivatization. Validation parameters, including interday precision (<14.8%), mean accuracy (102.4% ± 12.9%) and linear detection ranges of more than three orders of magnitude, indicate method reliability. Depending the investigated sample matrix, the majority of metabolites were successfully detected and quantified in native murine and cell culture derived sample materials. Furthermore, the method allowed to monitor the impact of a tryptophan-2,3-dioxygenase-inhibitor on kynurenine pathway in a cellular system and is suitable for multi-assay analyses using aliquots from the same cell extract. CONCLUSION: The described UPLC-MS/MS method provides a simple tool for the simultaneous quantification of kynurenine pathway metabolites. Due to its suitability for many physiological matrices, the method provides wide application for disease-related experimental settings.

Liquid chromatography-tandem mass spectrometry based quantification of arginine metabolites including polyamines in different sample matrices.

The conditionally essential amino acid arginine and its metabolic products play an important role in different biological processes, such as metabolic regulation of the immune response, including macrophage activation and polarization and regulation of T cell function. Furthermore, the polyamine spermidine has a role in aging and age-related diseases. Additionally, altered polyamine metabolism may be associated with neurodegenerative diseases, while polyamine levels may present useful biomarkers associated with severity of Parkinson's disease or with progression of non-alcoholic fatty liver disease. In the present study, a simple, derivatization-free hydrophilic interaction liquid chromatography based tandem mass spectrometry (LC-MS/MS) method is described, that allows the accurate quantification of arginine and related amine, polyamine and acetylated polyamine metabolites in different experimental sample matrices, such as cell lysates, cell culture supernatants and tissues. Ten arginine metabolites, including citrulline, agmatine, ornithine, putrescine, spermidine, spermine, N1-acetylspermidine, N1-acetylspermine, N1,N12-diacetylspermine and arginine in conjunction with the metabolic cofactors S-adenosylhomocysteine and S-adenosylmethionine are simultaneously analyzed within a total LC-MS/MS run time of 9.5 min. The assay is suitable to quantify concentration ranges over multiple orders of magnitude for all metabolites with averaged accuracies observed at 103.2% ± 6.8%, 99.0% ± 4.2% and 100.4% ± 4.3% in cell lysates, cell culture supernatant and tissue extracts, respectively. Inter-day coefficients of variation ranged from 5.9 to 14.8% in cell lysates, 6.7 to 14.6% in cell culture supernatants and 5.3 to 12.0% in tissue extracts. The method was successfully applied to cell culture systems of different origin as well as different murine tissues and organs. The herein described LC-MS/MS method provides a simple tool for a fast and simultaneous analysis of arginine metabolites, including polyamines and their respective metabolic cofactors. Assay performance characteristics demonstrate suitability for applications in different experimental and preclinical settings.

Predictors of severe anaphylaxis in Hymenoptera venom allergy: The importance of absence of urticaria and angioedema.

BACKGROUND: Severe anaphylaxis (SA) in Hymenoptera venom allergy has been associated with a number of risk factors. However, the effect of several of those risk factors on the severity of anaphylaxis is poorly defined. OBJECTIVE: To evaluate risk factors for SA in Hymenoptera venom allergy. METHODS: We evaluated data from 500 patients who were referred to our department for the diagnosis of Hymenoptera venom allergy during a period of 11 years to identify risk factors for SA. RESULTS: Six significant risk factors for SA were identified (P < .05): short interval from sting to reaction, absence of urticaria or angioedema (U/A) during anaphylaxis, older age, male sex, elevation of baseline serum tryptase (BST) level, and diagnosis of systemic mastocytosis. Moreover, elevation in BST level was significantly associated with the absence of U/A and older age. No association could be established between SA and comorbidities, concurrent cardiovascular medication, or the severity of the systemic reaction during the initiation of venom immunotherapy. CONCLUSION: Apart from BST and older age, male sex, short interval from sting to reaction, and absence of U/A are also risk factors for SA. The association between elevated BST level and SA was largely confined to those who had an absence of U/A after field sting, possibly because of the higher risk of concurrent systemic mastocytosis. Patients with an SA after a field sting do not have an elevated risk of systemic reactions during the initiation of venom immunotherapy compared with patients with mild anaphylaxis; therefore, additional preventive measures are not necessary.