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- Axelsson, John, et al.
(författare)
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Effects of Sustained Sleep Restriction on Mitogen-Stimulated Cytokines, Chemokines and T Helper 1/T Helper 2 Balance in Humans
- 2013
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recent studies suggest that acute sleep deprivation disrupts cellular immune responses by shifting T helper (Th) cell activity towards a Th2 cytokine profile. Since little is known about more long-term effects, we investigated how five days of sleep restriction would affect pro-inflammatory, chemotactic, Th1- and Th2 cytokine secretion. Methods: Nine healthy males participated in an experimental sleep protocol with two baseline sleep-wake cycles (sleep 23.00 - 07.00 h) followed by 5 days with restricted sleep (03.00 - 07.00 h). On the second baseline day and on the fifth day with restricted sleep, samples were drawn every third hour for determination of cytokines/chemokines (tumor necrosis factor alpha (TNF-alpha), interleukin (IL) -1 beta, IL-2, IL-4 and monocyte chemoattractant protein-1 (MCP-1)) after in vitro stimulation of whole blood samples with the mitogen phytohemagglutinin (PHA). Also leukocyte numbers, mononuclear cells and cortisol were analysed. Results: 5-days of sleep restriction affected PHA-induced immune responses in several ways. There was a general decrease of IL-2 production (p<.05). A shift in Th1/Th2 cytokine balance was also evident, as determined by a decrease in IL2/IL4 ratio. No other main effects of restricted sleep were shown. Two significant interactions showed that restricted sleep resulted in increased TNF-alpha and MCP-1 in the late evening and early night hours (p's<.05). In addition, all variables varied across the 24 h day. Conclusions: 5-days of sleep restriction is characterized by a shift towards Th2 activity (i.e. lower 1L-2/IL-4 ratio) which is similar to the effects of acute sleep deprivation and psychological stress. This may have implications for people suffering from conditions characterized by excessive Th2 activity like in allergic disease, such as asthma, for whom restricted sleep could have negative consequences. BAS AK, 1991, IMMUNOLOGICAL REVIEWS, V123, P5
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| 2. |
- Ingason, Haukur, et al.
(författare)
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The Metro Project : Final report
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report compiles the results from the METRO project. The different parts of theproject – design fires, evacuation, integrated fire control, smoke control, extraordinarystrain onconstructions and fire- and rescue operations – are presented separately.The most complicated and expensive part of the project was the performance of thelarge scale fire and explosion tests in the Brunsberg tunnel, where the maximum heatrelease rates measured from the metro wagon was 77 MW.The main results from the project are new recommendations regarding design firesin mass transport systems, identification of key factors for fire and smoke spread in tunnelsand at stations as well as regarding the difficulties for disabled persons to evacuatefrom trains in tunnels, new recommended types of way guiding systems, safer design incase of explosions in trains and evaluation of the fire and rescue services’ possibilitiesand limitations in underground mass transport systems.
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| 3. |
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| 4. |
- Ingason, Haukur, et al.
(författare)
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The Metro Project: Final Report
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The report compiles the results from the METRO-project. The different parts of the project; design fires, evacuation, integrated fire control, smoke control, extraordinary strain on constructions and fire- and rescue operations are presented separately. The most complicated and expensive part of the project was the performance of the large scale fire and explosion tests in the Brunsberg tunnel. The maximum heat release rates measured from the metro carriage was 77 MW. The maximum ceiling gas temperatures was 1118 °C. These values are high, and should be put into a perspective of the situation and the type of carriages used. The project is not recommending the highest values as the design fire, but values reflected in conditions. The egress study confirm that one of the major issues related to fire evacuation in underground transportation systems is that people often are reluctant to initiate an evacuation. New data show that participants moved with an average of 0.9 meters per second in the smoke filled environment (average visibility of 1.5–3.5 meters). A way-finding installation at the emergency exit, which consisted of a loudspeaker, was found to perform particularly well in terms of attracting people to the door. Two smoke control systems were simulated for a single exit metro station. The systems consisted of a pressurizing supply air system and mechanical exhaust ventilation system with and without platform screen doors. The results show that both the pressurizing supply air system and the mechanical exhaust air system provide effective smoke control for one exit metro station. The significance of the platform screen doors was shown to be important in relation to smoke control. Experiments and simulations have provided increased confidence in ability to simulate explosion scenarios to determine the pressure inside and outside a carriage and to be able to study variations of conditions such as carriage geometry and window designs. The explosion test performed show that an explosion with a relatively minor charge can significantly change the conditions for both evacuees and the rescue service. The results show that the conditions for evacuation and rescue operations can change dramatically as a result of a relatively minor explosion. Evaluation of methods and fire and rescue tactics in metros is given. Mapping of IR imaging as a tactical resource at tunnel fires was presented.
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| 5. |
- Lekander, Mats, et al.
(författare)
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Subjective health perception in healthy young men changes in response to experimentally restricted sleep and subsequent recovery sleep
- 2013
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Ingår i: Brain Behavior and Immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 34, s. 43-46
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Tidskriftsartikel (refereegranskat)abstract
- Sleep and subjective health are both prospectively related to objective indices of health and health care use. Here, we tested whether five days with restricted sleep and subsequent recovery days affect subjective health and is related to increased levels of circulating IL-6 and TNF-alpha and fatigue. Nine healthy men (23-28 years) went through a 6-week sleep protocol with subjects as their own controls in a repeated measures design with a total of 11 nights in a sleep laboratory. The experimental part of the protocol included three baseline days (sleep 23-07 h), five days with sleep restriction (03-07 h) and three recovery days (23-07 h) in the sleep laboratory. Subjective health and fatigue was recorded daily. Eight blood samples were drawn each day (every third hour) on 8 days of the protocol and analyzed with respect to IL-6 and TNF-alpha. Subjective health deteriorated gradually during restricted sleep (p = .002) and returned to baseline levels after three days of recovery. IL-6 and TNF-alpha did not change significantly. Fatigue increased gradually during sleep restriction (p = .001), which significantly contributed to the association between restricted sleep and subjective health. The study is the first to show that subjective health is directly responsive to changes in sleep length and related to increased fatigue. Thus, subjective health is differently appraised after manipulation of one of its presumed determinants. Larger experimental studies would be beneficial to further distinguish causation from association regarding the underpinnings of subjective health. (C) 2013 Published by Elsevier Inc.
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