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- Abelein, Axel, et al.
(författare)
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Formation of dynamic soluble surfactant-induced amyloid β peptide aggregation intermediates
- 2013
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 288:32, s. 23518-23528
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Tidskriftsartikel (refereegranskat)abstract
- Intermediate amyloidogenic states along the amyloid β peptide (Aβ) aggregation pathway have been shown to be linked to neurotoxicity. To shed more light on the different structures that may arise during Aβ aggregation, we here investigate surfactant-induced Aβ aggregation. This process leads to co-aggregates featuring a β-structure motif that is characteristic for mature amyloid-like structures. Surfactants induce secondary structure in Aβ in a concentration-dependent manner, from predominantly random coil at low surfactant concentration, via β-structure to the fully formed α-helical state at high surfactant concentration. The β-rich state is the most aggregation-prone as monitored by thioflavin T fluorescence. Small angle x-ray scattering reveals initial globular structures of surfactant-Aβ co-aggregated oligomers and formation of elongated fibrils during a slow aggregation process. Alongside this slow (minutes to hours time scale) fibrillation process, much faster dynamic exchange (k(ex) ∼1100 s(-1)) takes place between free and co-aggregate-bound peptide. The two hydrophobic segments of the peptide are directly involved in the chemical exchange and interact with the hydrophobic part of the co-aggregates. Our findings suggest a model for surfactant-induced aggregation where free peptide and surfactant initially co-aggregate to dynamic globular oligomers and eventually form elongated fibrils. When interacting with β-structure promoting substances, such as surfactants, Aβ is kinetically driven toward an aggregation-prone state.
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| 4. |
- Diab, Kerstin, et al.
(författare)
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Swedish Female Hairdressers' Views on Their Work Environment - A Qualitative Study.
- 2014
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Ingår i: Journal of Occupational Health. - 1348-9585. ; 56:2, s. 100-110
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Hairdressers have several work-related health hazards. Little is known of their strategies for the work environment. The aim of this study was to explore female hairdressers' own views on their physical, social and psychological work environment as possibilities of influencing it, implementation of their knowledge, financial impacts and how work-related symptoms affect their views. Methods: Fourteen hairdressers working for four years were subjected to open-ended interviews covering aspects of the physical, social and psychological work environment. Content analysis was applied. Results: An awareness of the impact of the work environment and the possibilities of influencing it emerged, but also an inability to achieve preventive improvements. This included reflections concerning ventilation, health issues, job strain, hair products, financial issues, knowledge from school and concern for having to leave the profession. The organization and acceptance of the work environment were important issues. Making the work environment an active part of their business was not common. Conclusions: Female hairdressers had an awareness of their work environment but lacked the means and strategies to make it an active part of their business. The main focus was on the customers and the work techniques. Having various symptoms did not alter this. Organizational and financial issues could put limitations on the work environment. Teachers were crucial in making the work environment interesting. Hairdressing was seen with advantages and disadvantages, and its future was seen as being insecure in terms of the occupational health risks. The hairdressers expressed a great pride in their profession providing possibilities for development.
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| 5. |
- Diab, Kerstin, et al.
(författare)
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Work-related airway symptoms, nasal reactivity and health-related quality of life in female hairdressers: a follow-up study during exposure.
- 2014
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 87:1, s. 61-71
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Hairdressers often complain of work-related rhinitis (WR). They are infrequently sensitized to persulphates. The cause and mechanism of the symptoms and the effects on their health-related quality of life (HRQoL) remains unclear. The objectives were to follow female hairdressers with WR mainly from bleaching powder regarding nasal reactivity to persulphate and to evaluate symptoms, HRQoL and inflammatory markers in nasal lavage during a working period after vacation and compared with hairdressers without symptoms and pollen allergic women. METHODS: Skin prick tests to persulphate were performed in the hairdressers. Participants kept a diary of symptoms and of work tasks (hairdressers only). They completed HRQoL questionnaires. Eosinophil cationic protein (ECP) in nasal lavage fluid was examined. The symptomatic hairdressers performed nasal challenges with persulphate before and after the exposure. RESULTS: Skin prick tests were negative. Although the nasal reactivity to persulphate did not change a steady increase in nasal symptoms, especially blockage, and in ECP was noticed in the symptomatic hairdressers. The HRQoL deteriorated in the symptomatic hairdressers indicating an effect on their working situation and daily life. The atopics had more, but varying symptoms (itching, sneezing and secretion). CONCLUSIONS: The difference in the clinical picture between the symptomatic hairdressers and the pollen allergic women, the increase in symptoms and ECP in the nasal lavage support the view that a sensitization to hairdresser chemicals by a mechanism not yet understood is operating. The deterioration of the HRQoL in the symptomatic hairdressers indicates a considerable effect on their life.
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| 8. |
- Hagerman, Inger, et al.
(författare)
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Effects on heart rate variability by artificially generated indoor nano-sized particles in a chamber study
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 88, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- Background: Airborne particles are associated with increased morbidity and mortality due to respiratory and cardiovascular diseases in polluted areas. There is a growing interest in nano-sized particles with diameter < 100 nm and their potential health effects. Heart rate variability (HRV) is a noninvasive method for cardiovascular risk prediction in high prevalent groups. Aim of study: The aim was to evaluate the impact of nano-sized indoor air particles on HRV for healthy and adult females. Methods: All exposures were performed as controlled chamber experiments with particle exposure from burning candles, terpene + ozone reactions or filtered air in a double-blind cross over design. Twenty-two healthy females were investigated during 10 min periods at different exposures and the reactivity in high frequency (HF) spectral band of HRV were computed. Results: Heart rate was unchanged from baseline values in all groups during all experimental settings. HF power of HRV tended to increase during exposure to particles from burning candle while particles from terpene + ozone reactions tended to decrease HF power. Conclusions: Exposure to nano-sized particles of burning candles or terpene + ozone reactions results in different patterns of heart rate variability, with signs of altered autonomic cardiovascular control. Practical implications: This study indicates that the HRV method may be used for information on physiological responses of exposure to different nano-sized particles and contribute to the understanding of mechanisms behind health effects of particle exposures. (C) 2014 The Authors. Published by Elsevier Ltd.
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| 10. |
- Hedmer, Maria, et al.
(författare)
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Exposure to respirable dust and manganese and prevalence of airways symptoms, among Swedish mild steel welders in the manufacturing industry.
- 2014
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 87:6, s. 623-634
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Tidskriftsartikel (refereegranskat)abstract
- Welding fume consists of metal fumes, e.g., manganese (Mn) and gases, e.g., ozone. Particles in the respirable dust (RD) size range dominate. Exposure to welding fume could cause short- and long-term respiratory effects. The prevalence of work-related symptoms among mild steel welders was studied, and the occupational exposure to welding fumes was quantified by repeated measurements of RD, respirable Mn, and ozone. Also the variance components were studied.
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