AimsObstructive sleep apnea (OSA) is a risk factor for steroid-resistant (SR) asthma. However, the underlying mechanism is not well defined. This study aimed to investigate how chronic intermittent hypoxia (CIH), the main pathophysiology of OSA, influenced the effects of glucocorticoids (GCs) on asthma.Main MethodsThe effects of dexamethasone (Dex) were determined using the ovalbumin (OVA)-challenged mouse model of asthma and transforming growth factor (TGF)-β treated airway smooth muscle cells (ASMCs), with or without CIH. The p38 MAPK signaling pathway activity was then detected in the mouse (n = 6) and ASMCs models (n = 6), which were both treated with the p38 MAPK inhibitor SB239063.Key FindingsUnder CIH, mouse pulmonary resistance value, inflammatory cells in bronchoalveolar lavage fluid (BALF), and inflammation scores increased in OVA-challenged combined with CIH exposure mice compared with OVA-challenged mice (p < 0.05). These indicators were similarly raised in the OVA + CIH + Dex group compared with the OVA + Dex group (P < 0.05). CIH exposure enhanced the activation of the p38 MAPK pathway, oxidative stress injury, and the expression of NF-κB both in lung tissue and ASMCs, which were reversed by treatment with Dex and SB239063. In the in vitro study, treatment with Dex and SB239063 decreased ASMCs proliferation induced by TGF-β combined with CIH and suppressed activation of the p38 MAPK pathway, oxidative stress injury, and NF-κB nuclear transcription (p < 0.05).SignificanceThese results indicated that CIH decreased GC sensitivity by activating the p38 MAPK signaling pathway.
Lysozyme molecularly imprinted polymer membranes(MIMs) were prepared using polyacrylamine as matrix. Direct detection of fluorescence intensity of absorbed lysozyme(Lyz) on the MIMs was achieved for the fast detection of lysozyme. The surface morphology of polymer was characterized by SEM. Adsorption time and rebinding solution pH were optimized to improve recognition ability of MIMs for lysozyme. The results showed that the MIMs had a high selection and recognition ability for the lysozyme protein.
Two 1-allyl-3-butylimidazolium ionic liquids were synthesized and polymerized in- column as stationary phases in capillary gas chromatography. The influences of different counter ions (hexafluorophosphate, tetrafluoroborate) were studied. The results indicated that 1-allyl-3-butyl- imidazolium ionic liquids possessed good column coating properties and chromatographic separation abilities after polymerized in-column. The Grobs mixture, alcohols and alkanes and aromatic position isomers, such as xylene, nitrotoluene, dichlorobenzene and cresol were separated well. These polymeric ionic liquids gave potential to separate some complex compounds including alcohol, amine, ester etc.
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