@article{ZinnerHauserBornetal.2015,
  author    = {Zinner, Christoph and Hauser, Anna and Born, Dennis-Peter and Wehrlin, Jon P. and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {Influence of Hypoxic Interval Training and Hyperoxic Recovery on Muscle Activation and Oxygenation in Connection with Double-Poling Exercise},
  series = {PLoS One},
  volume    = {10},
  journal   = {PLoS One},
  number    = {10},
  doi       = {10.1371/journal.pone.0140616},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126299},
  pages     = {e0140616},
  year      = {2015},
  abstract  = {Here, we evaluated the influence of breathing oxygen at different partial pressures during recovery from exercise on performance at sea-level and a simulated altitude of 1800 m, as reflected in activation of different upper body muscles, and oxygenation of the m. triceps brachii. Ten well-trained, male endurance athletes (25.3±4.1 yrs; 179.2±4.5 cm; 74.2±3.4 kg) performed four test trials, each involving three 3-min sessions on a double-poling ergometer with 3-min intervals of recovery. One trial was conducted entirely under normoxic (No) and another under hypoxic conditions \((Ho; F_iO_2 = 0.165)\). In the third and fourth trials, the exercise was performed in normoxia and hypoxia, respectively, with hyperoxic recovery \((HOX; F_iO_2 = 1.00)\) in both cases. Arterial hemoglobin saturation was higher under the two HOX conditions than without HOX (p<0.05). Integrated muscle electrical activity was not influenced by the oxygen content (best d = 0.51). Furthermore, the only difference in tissue saturation index measured via near-infrared spectroscopy observed was between the recovery periods during the NoNo and HoHOX interventions (P<0.05, d = 0.93). In the case of HoHo the athletes' \(P_{mean}\) declined from the first to the third interval (P < 0.05), whereas Pmean was unaltered under the HoHOX, NoHOX and NoNo conditions. We conclude that the less pronounced decline in \(P_{mean}\) during 3 x 3-min double-poling sprints in normoxia and hypoxia with hyperoxic recovery is not related to changes in muscle activity or oxygenation. Moreover, we conclude that hyperoxia \((F_iO_2 = 1.00)\) used in conjunction with hypoxic or normoxic work intervals may serve as an effective aid when inhaled during the subsequent recovery intervals.},
  language  = {en}
}
@article{TwisselmannPagelKuenstneretal.2021,
  author    = {Twisselmann, Nele and Pagel, Julia and K{\"u}nstner, Axel and Weckmann, Markus and Hartz, Annika and Glaser, Kirsten and Hilgendorff, Anne and G{\"o}pel, Wolfgang and Busch, Hauke and Herting, Egbert and Weinberg, Jason B. and H{\"a}rtel, Christoph},
  title     = {Hyperoxia/Hypoxia Exposure Primes a Sustained Pro-Inflammatory Profile of Preterm Infant Macrophages Upon LPS Stimulation},
  series = {Frontiers in Immunology},
  volume    = {12},
  journal   = {Frontiers in Immunology},
  issn      = {1664-3224},
  doi       = {10.3389/fimmu.2021.762789},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250356},
  year      = {2021},
  abstract  = {Preterm infants are highly susceptible to sustained lung inflammation, which may be triggered by exposure to multiple environmental cues such as supplemental oxygen (O\(_2\)) and infections. We hypothesized that dysregulated macrophage (MФ) activation is a key feature leading to inflammation-mediated development of bronchopulmonary dysplasia (BPD) in preterm infants. Therefore, we aimed to determine age-dependent differences in immune responses of monocyte-derived MФ comparing cord blood samples derived from preterm (n=14) and term (n=19) infants as well as peripheral blood samples from healthy adults (n=17) after lipopolysaccharide (LPS) exposure. Compared to term and adult MФ, LPS-stimulated preterm MФ showed an enhanced and sustained pro-inflammatory immune response determined by transcriptome analysis, cytokine release inducing a RORC upregulation due to T cell polarization of neonatal T cells, and TLR4 surface expression. In addition, a double-hit model was developed to study pulmonary relevant exposure factors by priming MФ with hyperoxia (O\(_2\) = 65\%) or hypoxia (O\(_2\) = 3\%) followed by lipopolysaccharide (LPS, 100ng/ml). When primed by 65\% O\(_2\), subsequent LPS stimulation in preterm MФ led to an exaggerated pro-inflammatory response (e.g. increased HLA-DR expression and cytokine release) compared to LPS stimulation alone. Both, exposure to 65\% or 3\% O\(_2\) together with subsequent LPS stimulation, resulted in an exaggerated pro-inflammatory response of preterm MФ determined by transcriptome analysis. Downregulation of two major transcriptional factors, early growth response gene (Egr)-2 and growth factor independence 1 (Gfi1), were identified to play a role in the exaggerated pro-inflammatory response of preterm MФ to LPS insult after priming with 65\% or 3\% O\(_2\). Preterm MФ responses to LPS and hyperoxia/hypoxia suggest their involvement in excessive inflammation due to age-dependent differences, potentially mediated by downregulation of Egr2 and Gfi1 in the developing lung.},
  language  = {en}
}