Objective:To study the clinical characteristics and management strategies of patients with chronic obstructive pulmonary disease (COPD) in high-altitude areas.Methods:An observational cross-sectional study was conducted in 79 stable COPD patients who visited the outpatient of Respiratory Medicine at Tibet Autonomous Region People′s Hospital and Peking University Third Hospital from August 3 rd 2020 to November 30 th 2020. Patients were divided into Lhasa group ( n=44) and Beijing group ( n=35). The differences of clinical characteristics including demographic characteristics, risk factors, respiratory symptoms, comorbidities, medications and spirometry were analyzed. Further comparative analysis was conducted on the clinical characteristics of smokers ( n=15) and non-smokers ( n=29) in Lhasa group. Results:The proportion of female patients and biofuel exposure in Lhasa group was significantly higher than Beijing group (56.8% vs 0, 86.4% vs 0, both P<0.001). The proportion of smokers in Lhasa group was significantly lower than Beijing group (34.1% vs 100%, P<0.001). The mean score of COPD assessment test (CAT) in Lhasa group was significantly higher than Beijing group (21.27 vs 9.17, P<0.001). The proportion of acute exacerbations ≥2 in the past year in Lhasa group was significantly higher than Beijing group (31.8% vs 11.4%, P=0.032). The median percentage of forced vital capacity in the first second of predicted value (FEV 1%pred) of patients in Lhasa group was significantly higher than Beijing group (63% vs 38%, P<0.001). The proportion of patients treated by inhaled corticosteroid/long-acting β 2-agonist (ICS/LABA) and inhaled long-acting muscarinic antagonists (LAMA) in Lhasa group was significantly lower than Beijing group (4.5% vs 60.0%, 0 vs 65.7%, both P<0.001). There were no significant differences in CAT score, number of acute exacerbations in the past year and lung function between smokers and non-smokers in Lhasa group. Conclusions:Compared with those patients in Beijing, the majority of patients with COPD living in Lhasa are female, with a low proportion of smokers and a high proportion of biofuel exposure. Although their lung function is better, their respiratory symptoms are more severe with more acute exacerbations in the past year, and most patients do not receive standardized medication.

Objective:To explore the effect of swallowing fluids of different viscosities in different head positions on the surface electromyography (sEMG) of the suprahyoid muscles.Methods:Twenty healthy adults were asked to swallow 5ml of liquids with 5 different viscosities in 3 different head positions. sEMG signals were recorded from their suprahyoid muscles in real time. The interactions between viscosity, head position and suprahyoid muscle activation were determined using simple effect analysis.Results:Significant head position and viscosity effects were observed. In the head-turning-right or the right head-flexion position, the net amplitude values of the left suprahyoid muscles were significantly higher than those from the right side when swallowing fluid of the same viscosity. Meanwhile, the net amplitude values of the left suprahyoid muscles increased gradually and significantly from the neutral position to the head-turning-right and the right head-flexion positions. When swallowing fluid with a viscosity of 0 to 3, the net amplitude values of the right suprahyoid muscles in the right head-flexion position were significantly lower than in the neutral and right head-flexion positions. With a viscosity of 4 the values of the former were significantly higher than the latter. The net amplitude of the left superhyoid muscle group when swallowing zero-viscosity food in a head-turning-right position was significantly lower than that when swallowing food of viscosity 1 to 4. In the right head-flexion position, the net amplitude of the left superhyoid muscle group when swallowing zero-viscosity food was significantly lower than that when swallowing food of viscosity 2 to 4. When swallowing fluid of viscosity 1 it was also significantly lower than that when swallowing food of viscosity 3 to 4. In the same position, the net amplitude of the right suprhyoid muscle group when swallowing fluid of viscosity 4 was significantly higher than that with a viscosity of 0 to 1. At viscosity 3 it was significantly higher than with a viscosity of 1.Conclusion:Swallowing fluids of different viscosities in different head positions can affect the contraction of the suprahyoid muscles to different degrees.

Objective To study the effect of the trauscranial magnetic stimulation on the migration of phosphoprotein-enriched astrocytes-15kDa (PEA-15).Methods Third or fourth generation rat astrocytes cuhured in vitro were divided into a control group,a transfected group,a magnetic stimulation group and a transfected + magnetic stimulation group.The control group was undergone transfect of negative siRNA.In transfected group and the transfected + magnetic stimulation group the liposome in the astrocyte was transfected instantly with chemically synthesized PEA-15 siRNA,so as to interfere with the expression of PEA-15 protein.Magnetic stimulation was applied to both tranfected and transfected + magnetic stimulation groups 24 h after plating of astrocytes at 1 Hz and 60％ the maximal output of the stimulator.Cell scratch tests were used to assess the astrocytes' migration,and Western blotting was applied to detect the expression of PEA-15 and protein phosphorylation.Results Compared with the control group,the expression of PEA-15 protein decreased significantly in the transfected groups.The cell migration in the transfected group,the magnetic stimulation group,and the transfected + magnetic stimulation group was significantly greater than in the control group.Compared with the control group,the phosphorylation of PEA-15 increased significantly in the magnetic stimulation group.Conclusion When PEA-15 expression is interfered with,the migration of astrocytes increases significantly.Magnetic stimulation may promote the migration of astrocytes by enhancing PEA-15 phosphorylation.

Objective To examine the effect of the inter-stimulus interval (ISI) in magnetic stimulation (MS) on astrocyte migration and its related mechanism.Methods Cultured astrocytes were treated with intermittent MS with intervals of 1,5 and 10 seconds.The PEA-15 inhibitor BisI (10 μmol/ml) and the ERK1/2 inhibitor U0126 (10 μmol/ml) were administered and cell migration assays evaluated the astrocytes' migration.The expression of phosphorylated ERK1/2 and PEA-15 was detected using Western blotting.Results The 1 second interval significantly facilitated astrocyte migration,the phosphorylation of PEA-15 and ERK1/2,and the expression of MMP-9 (browse matrix metalloproteinase-9).The addition of Bis I significantly reduced the production of phosphorylated ERK1/2 and MMP-9,as well as astrocyte migration induced by MS.In addition,pretreatment with U0126 also significantly decreased the astrocyte migration induced by MS.Conclusion 1s-ISI MS can induce PEA-15 activation and subsequently lead to ERK1/2 phosphorylation and upregulation of MMP-9,which may contribute to the migration of astrocytes.

Objective To examine the molecular mechanism involved in astrocyte migration induced by magnetic stimulation (MS),and the role of high mobility group box 1 (HMGB1) in migration.Methods Astrocytes were isolated from the cortical tissues of 2-3 day old Sprague-Dawley rats and divided into a stimulus group given MS and a control group without MS.The stimulus group was further divided into an experimental group and a control group,with the former pre-stimulated with 10 μmol/ml U0126 for 30 minutes and no pre-stimulation for the latter.The cells in the experimental group were also randomly divided into siRNA and HMGB1-siRNA transfection groups to examine the role of HMGB1 in astrocyte migration induced by MS.The SiRNA group was transfected with HMGB1 siRNA.Western blotting was used to detect any effect of MS on HMGB1 and extracellular signal-regulated kinase1/2 (ERK1/2).The migration of astrocytes was detected using the scratch assay.Results MS (10 Hz) can promote the phosphorylation of ERK,increase the migration of astrocytes and the expression of HMGB1.After the U0126 treatment and transfection with HMGB1 siRNA,the effects of MS on expression of HMGB1 and migration of astrocytes decreased significantly.Conclusions Magnetic stimulation-mediated migration of astrocytes via activation of the ERK pathway phosphorylation and autocrine of HMGB1.

Aim To investigate the combined effect of mangiferin and ephedrine as well as explore its underlying mechanism in mouse model of allergic asthma.Methods The mouse model of asthma was sensitized and challenged with ovalbumin(OVA).The behaviors of mice during the challenging period were observed.Continuous autonomic activities of mice after 1 h of drug treatment were monitored with the autonomic activity recorder for 14 days.The total and differential cells in peripheral blood were counted.Histological study of lung sections on airway inflammation was carried out with haematoxylin and eosin(HE) staining.The levels of ovalbumin-specific immunoglobulin E(OVA-sIgE) and(Cyclic Adenosine monophosphate) cAMP in serum were detected by enzyme-linked immunosorbent assay(ELISA).The mRNA expression of cytokines mainly produced by Th1/Th2 lymphocytes such as IFN-γ and IL-4, IL-5 were semi-quantitatively analyzed with reverse transcription polymerase chain reaction(RT-PCR).Results Combination treatment and mangiferin could reduce the aberrantly autonomic activity caused by ephedrine in mice.Compared with the model group, asthmatic symptoms in all treatment groups could be significantly relieved, the pathological changes of lung tissue were improved and airway inflammation was reduced.The effect of combined treatment was better than that of mangiferin treatment alone.Compared with the model group, the total number of white blood cells(WBC) and the eosinophils(EOS) ratio in peripheral blood in all treatment groups decreased, the level of OVA-sIgE declined and the level of cAMP increased in serum.Combination treatment could lower mRNA expressions of IL-4 and IL-5 from Th2 lymphocytes and increase the mRNA expressions of IFN-γ released by Th1 lymphocytes.Conclusions The effect of combined therapy of mangiferin and ephedrine is better than that of mangiferin treated alone, meanwhile it can reduce the side effects caused by ephedrine.The underlying mechanism is mainly associated with attenuating Th1/Th2 cytokine imbalance and increasing the level of cAMP.

Objective To observe the effect of low-frequency, repetitive transcranial magnetic stimulation ( rTMS) at different frequencies on the cognitive function of traumatic brain injury patients with a history of epilepsy. Methods Sixty traumatic brain injury patients were randomly divided into a 0. 5 Hz group, a 1. 0 Hz group and a control group, each of 20. In addition to routine drug therapy and cognition training, the control group was given fake stimulation, the 0.5 Hz group was treated with 0.5 Hz rTMS, and the 1.0 Hz group was provided with 1.0 Hz rTMS for 4 weeks, eleven times per week. Before and after treatment, the cognitive function of all three groups was assessed using the Montreal cognitive assessment ( MOCA) , the Rivermead behavior memory test ( RBMT) and a symbol can-cellation test. The number of patients reporting headache or epilepsy during the treatment period was also counted. Results During the treatment, there was no headache case in any of the groups, and no significant difference was found in the occurrence of seizures. After the treatment, all of the measurements in all 3 groups had improved signifi-cantly. The average MOCA and RBMT scores in the 1.0 Hz group were all significantly better than those in the control group, but there was no significant difference between the 0.5 Hz group and the control group. The symbol cancella-tion test efficiency of the 1. 0 Hz group was not significantly better than that of the 0. 5 Hz and control groups. Conclusions Repeated 1.0 Hz transcranial magnetic stimulation can significantly improve cognition after traumatic brain injury among patients with a history of epilepsy without increasing the risk of seizures.

Objective To observe the surface electromyographic characteristics of the bilateral submen-tal muscles in dysphagia secondary to unilateral brainstem stroke. Methods A total of 25 subjects were recrui-ted. There were 8 stroke patients with dysphagia secondary to a left brainstem stroke and 7 stroke patients with dysphagia secondary to a right brainstem stroke. There were also 10 healthy controls matched in age and gender. The duration and peak amplitude of the submental muscle when swallowing 5 ml of warm water were recorded u-sing a surface electromyograph. Results The average amplitude of the left submental muscle in patients with a left brainstem stroke was significantly longer than that of those with a right brainstem stroke, but no significant differences in average duration were observed. Conversely, the amplitude of the right submental muscle in pa-tients with a right brainstem stroke was significantly longer than that of those with left brainstem stroke, but again there were no significant differences in duration. No significant differences were observed among the healthy con-trols. The amplitude and duration of both the affected and healthy sides of the patients were of course significantly longer or stronger than those of the healthy controls. Conclusion The swallowing function of the bilateral sub-mental muscles may be impaired among unilateral stroke survivors with dysphagia. The damage on the affected side is more severe than on the opposite side.

BACKGROUND:Hematopoietic stem cel transplantation has therapeutic effects on many diseases, but its application has some limitations, such as cel harvesting and age-limited number of cels.
OBJECTIVE: To investigate the application value of bone marrow mesenchymal stem cels in hematopoietic stem cel transplantation for sensitized and non-sensitized BALB/c mice.
METHODS: Bone marrow cels derived from BALB/c mice were isolated and culturedin vitro to harvest mesenchymal stem cels using adherent method. The cel surface markers were detected by flow cytometry. A murine model of sensitization was established by transfusion of alogeneic spleen cels. Mesenchymal stem cels labeled with green fluorescent dye were transplanted into non-sensitized and sensitized recipient mice, and the homing of mesenchymal stem cels in vivowas monitored at different time points post transplantation. Additionaly, under irradiation pretreatment, sensitized BALB/c mice under irradiation were subjected to combined transplantation of alogeneic bone marrow cels and syngeneic mesenchymal stem cels. Survival rate of BALB/c mice was monitored daily.
RESULTS AND CONCLUSION: At 48 hours after transplantation, mesenchymal stem cels in sensitized and non-sensitized recipients were homing to the spleen and bone marrow, respectively. In the experiment of hematopoietic stem cel transplantation, the sensitized recipients died at 12-15 days after combined transplantation, with a median of 14 days; however, the sensitized recipients only undergoing alogeneic bone marrow cel transplantation had a survival median of 13 days. These findings indicate that the transplanted mesenchymal stem cels in sensitized recipients are mainly homing to the spleen and bone marrow, but the combination transplantation cannot enhance the transplantation of alogeneic hematopoietic stem/progenitor cels in sensitized recipients.

Objective To assess the effect of stromal cell-derived factor 1 (SDF-1) on the migration of neural stem cells and recovery of lower limb function after spinal cord injury (SCI).Methods A modified version of Allen's method was used to establish a SCI model in each of 96 adult male Sprague-Dawley rats.They were then randomly divided into group A which received an injection of phosphate buffer solution,group B which received an injection of neural stem cells,group C which received a combination of SDF-1 and neural stem cells,and group D which received AMD3100 and neural stem cells 7 days after the modeling.The functioning of the hind limbs of all of the rats was assessed on the 7th,14th,21st and 28th day after the modeling.The rats were then sacrificed and frozen sections of their spinal cords were stained with hematoxylin-eosin (HE) and marked with CM-Dil under fluorescent light.Results An accumulation of fluorescing cells were observed in spine cords from both group B and C,with the counts of group B [(23.6 ±3.7),(18.9 ±5.6)and(15.2 ±4.3) respectively] at the day 14,21 and 28 after modeling significantly smaller than those of group C [(27.4 ± 4.7),(20.4 ± 5.2) and (18.3 ± 3.9) respectively].During the same period of time,the average BBB scores of groups B and C were significantly better than those of groups A and D.Moreover,the average score of group C was significantly higher than group B's at all time points.Conclusions Transplanted neural stem cells can migrate to the injured site,surviving and differentiating to promote the recovery of limb function in rats with spinal cord injury.SDF-1 can promote that migration and proliferation.Moreover,CXCR4 receptor's antagonist AMD3100 can significantly hinder neural stem cells' migration to the injured site on the spinal cord.