| 1. |
- Benedict, Christian, et al.
(författare)
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Enhancing influence of intranasal interleukin-6 on slow-wave activity and memory consolidation during sleep
- 2009
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Ingår i: The FASEB Journal. - : FASEB. - 0892-6638 .- 1530-6860. ; 23:10, s. 3629-3636
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Tidskriftsartikel (refereegranskat)abstract
- The cytokine IL-6 has been considered to exert neuromodulating influences on the brain, with promoting influences on sleep. Sleep enhances the consolidation of memories, and, in particular, late nocturnal sleep also represents a period of enhanced IL-6 signaling, due to a distinctly enhanced availability of soluble IL-6 receptors during this period, enabling trans-signaling of IL-6 to neurons. Thus, a contribution of IL-6 to sleep-dependent memory consolidation is hypothesized. To test this hypothesis, we compared effects of intranasally administered IL-6 (vs. placebo) on sleep-dependent consolidation of declarative (neutral and emotional texts, 2-dimensional object location) and procedural (finger sequence tapping) memories in 17 healthy young men. IL-6 distinctly improved the sleep-related consolidation of emotional text material (P<0.03), which benefits mostly from sleep in the second night-half, in which rapid eye movement sleep (REM) dominates the non-REM-REM sleep cycle. During this second night-half, the amount of electroencephalogram slow-wave activity (0.5-4 Hz) distinctly increased after IL-6 (P<0.01). Other types of memory were not affected. The ability of IL-6 to enhance sleep-associated emotional memory consolidation highlights an example of a functional interaction between the central nervous and immune system.
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| 2. |
- Nielsen, Niels D, et al.
(författare)
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Apneic oxygenation combined with extracorporeal arteriovenous carbon dioxide removal provides sufficient gas exchange in experimental lung injury
- 2008
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Ingår i: ASAIO journal (1992). - 1058-2916 .- 1538-943X. ; 54:4, s. 401-405
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Tidskriftsartikel (refereegranskat)abstract
- We hypothesized that apneic oxygenation, using an open lung approach, combined with extracorporeal CO2 removal, would provide adequate gas exchange in acute lung injury. We tested this hypothesis in nine anesthetized and mechanically ventilated pigs (85-95 kg), in which surfactant was depleted from the lungs by repeated lung lavage. After a lung recruitment maneuver, the tracheal tube was connected to 20 cm H2O continuous pressure (100% O2) for oxygenation of the blood. A pumpless membrane ventilator (interventional lung assist by Novalung) was connected in an arteriovenous shunt for CO2 removal. PaO2 and PaCO2 were recorded for 3.5 hours. PaO2 was 464 (403, 502) mm Hg (median and interquartile range) throughout the experiment. The O2 uptake through the lungs was 185 (164, 212) ml/min. PaCO2 increased asymptotic towards 60 mm Hg. The CO2 removal through the membrane ventilator was 180 (150, 180) ml/min. Thus, the method provided adequate gas exchange in this experimental model, suggesting that it might have potential as an alternative treatment modality in acute lung injury.
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| 3. |
- Schmid, M, et al.
(författare)
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Short-term sleep loss decreases physical activity under free-living conditions but does not increase food intake under time-deprived laboratory conditions in healthy men
- 2009
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 90:6, s. 1476-1482
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Tidskriftsartikel (refereegranskat)abstract
- Background: Short sleep duration is correlated with an increased risk of developing obesity and cardiovascular disease, but the mechanisms behind this relation are largely unknown.Objective: We aimed to test the hypothesis that acute sleep loss decreases physical activity while increasing food intake, thereby shifting 2 crucial behavioral components of energy homeostasis toward weight gain.Design: In 15 healthy, normal-weight men, spontaneous physical activity was registered by accelerometry during the entire experiment, and food intake as well as relevant hormones were assessed during a 15-h daytime period after 2 nights of regular sleep (bed time: 2245-0700) and after 2 nights of restricted sleep (bed time: 0245-0700). Experiments were performed in a crossover design.Results: Sleep restriction significantly decreased physical activity during the daytime spent under free-living conditions after the first night of sleep manipulation (P = 0.008). Also, intensities of physical activity were shifted toward lower levels, with less time spent with intense activities (P = 0.046). Total energy intake, feelings of hunger, and appetite as well as ghrelin and leptin concentrations during day 2 remained unaffected by acute sleep restriction.Conclusions: In contrast to our expectation, short-term sleep loss neither increased food intake nor affected concentrations of the hunger-regulating hormones leptin and ghrelin. However, the observed decrease in daytime physical activity may point to another potentially important behavioral mechanism for the health-impairing influence of sleep loss.
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