ABSTRACT
Intermittent hypoxia (IH) could induce cognitive impairment through oxidative stress and inflammation. However, the degree of cell damage is closely related to the IH stimulus frequency. IH stimulation with different frequencies also induces opposite results on neuronal cell lines. Therefore, this study was aimed to compare the effects of IH stimulation with three different frequencies on murine hippocampal neuronal HT22 cell activity, and to explore the molecular mechanism of the IH stimulus frequency-related neuron injury. HT22 cells were cultured and divided into control group and three IH stimulation groups with different frequencies. Oxygen concentration in the chamber was circulated between 21% and 1% (IH1 group, 6 cycles/h; IH2 group, 2 cycles/h; IH3 group, 0.6 cycle/h). Cell morphology was observed at 6, 12, 24 and 48 h of IH treatment. Cell viability was determined by the CCK-8 kit, lactate dehydrogenase (LDH) content in cell supernatant was determined by LDH kit, oxidative stress level was detected by the reactive oxygen species (ROS) probe, and protein expression levels of hypoxia inducible factor-1α (Hif-1α) and phosphorylated nuclear factor κB (p-NF-κB) were detected by Western blot. The results showed that, compared with control group, cell number and activity in the three IH groups were decreased, LDH content and ROS levels were increased with the prolongation of IH stimulation time, and the changes were most obvious in the IH1 group among those of the three IH groups. Hif-1α expression and the p-NF-κB/NF-κB ratio were also up-regulated with the prolongation of IH stimulation time, and the changes of IH1 group were the most significant. These results suggest that IH stimulation induces oxidative stress injury in HT22 cells, which is related to increased Hif-1α expression and NF-κB phosphorylation. Moreover, the higher frequency of IH stimulation induces more serious cell injury.
Subject(s)
Animals , Mice , Cell Hypoxia , Cell Survival , Hypoxia , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , NF-kappa B/metabolism , Oxidative Stress , Reactive Oxygen SpeciesABSTRACT
Supraglottic and pharyngeal sensory abnormalities contribute to dysphagia and aspiration.Air-pulse stimulation makes the air pulse as stimulator to improve swallowing function. This paper reviewed some sorts of air-pulse stimulation equipment,in term of structure and operation,and its application in evaluation and training of swallowing function.
ABSTRACT
Objective To design a new type of rehabilitation device to execute electrode fixation and precision positioning during transcranial electrical stimulation.Methods The device was composed of a positioning cap,a soft rubber keel scaffold, an inlaid nut,a unionbolt,an electrical stimulation shim and etc.The electrode was put into the shim at the target site,and fixation and positioning were realized by regulating the depth of the bolt into the slot to change the attachment between the electrode fixing cushion and cranial skin,and then electrical stimulation therapy could be carried out reliably and accurately. Results The device gained advantages over the traditional means in fixation time in one time, dropping-off rate, patient satisfaction and easy operation.Conclusion This device behaves well in simple structure,easy manufacture,low cost,fixation and large applicability to kinds of population and electrical stimulators,and enhances the reliability of transcranial electrical stimulation therapy to some extent.