Neuroplasticity of visual brain network induced by hypoxia.

The effects of hypoxia on brain function remain largely unknown. This study aimed to clarify this issue by visual-stimulated functional magnetic resonance imaging design. Twenty-three college students with a 30-d high-altitude exposure were tested before, 1 week and 3 months after returning to sea level. Brain functional magnetic resonance imaging and retinal electroretinogram were acquired. One week after returning to sea level, decreased blood oxygenation level dependent in the right lingual gyrus accompanied with increased blood oxygenation level dependent in the frontal cortex and insular cortex, and decreased amplitude of electroretinogram a-wave in right eye; moreover, the bilateral lingual gyri showed increased functional connectivity within the dorsal visual stream pathway, and the blood oxygenation level dependent signals in the right lingual gyrus showed positive correlation with right retinal electroretinogram a-wave. Three months after returning to sea level, the blood oxygenation level dependent signals recovered to normal level, while intensively increased blood oxygenation level dependent signals in a broad of brain regions and decreased retinal electroretinogram were also existed. In conclusion, hypoxic exposure has long-term effects on visual cortex, and the impaired retinal electroretinogram may contribute to it. The increased functional connectivity of dorsal stream may compensate for the decreased function of retinal photoreceptor cells to maintain normal visual function.

H2H rehabilitation care promotes high quality recovery of patients with lung cancer comorbid with chronic obstructive pulmonary disease.

H2H is a patient and family-centered approach that integrates hospital and home care, emphasizing continuity, individualized rehabilitation training, and the active participation of patients and their families. However, it is still unclear whether H2H improves the efficacy for patients with COPD and lung cancer. This study investigated the efficacy of Hospital-to-Home (H2H) rehabilitation nursing for lung cancer patients with Chronic Obstructive Pulmonary Disease (COPD). We conducted a retrospective analysis to the clinical data of 95 patients treated in the Pingdingshan University Medical College from January 2018 to January 2020. We compared the effects of conventional nursing (control group, n=45) and H2H nursing (observation group, n=50) on the clinical efficacy for the patients. In this study, after nursing intervention, the quality of life and adverse emotions in the observation group were significantly improved compared to the control group (P<0.0001). Moreover, the lung function and blood oxygen saturation of patients in the H2H nursing model improved after the intervention (P<0.0001). In addition, there was no difference in the 3-year survival rate between the control group and the observation group (P=0.260). Multivariate COX regression analysis showed that the nursing scheme had no effect on the patients' 3-year survival, but the SAS score, SDS score, and CEA were independent prognostic factors affecting the 3-year survival rate (P<0.05). These results demonstrate that H2H rehabilitation care significantly improves the quality of life, emotional health, and lung function of patients with COPD and lung cancer, but does not affect the patients' 3-year survival rate.

Decrease in Cerebral Blood Flow after Reoxygenation Is Associated with Neurological Syndrome Sequelae and Blood Pressure.

Changes in cerebral blood flow (CBF) and regulation of cerebral circulation occur at high altitude (HA). However, the changes in CBF and their associations with neurological syndrome sequelae and blood pressure after subjects return to the lowlands remain unclear. In this study, the subjects were 23 college students who were teaching at an altitude of 4300 m for 30 days. These subjects were studied before reaching the HA (Test 1), one week after returning to the lowlands (Test 2), and three months after returning to the lowlands (Test 3). Symptom scores for de-acclimatization syndrome were evaluated. Changes in CBF were measured using the magnetic resonance imaging arterial spin labeling (ASL) technique. Additionally, the velocity of CBF in the cerebral arteries was measured using a transcranial doppler (TCD). In Test 2 vs. Test 1, the peak systolic velocity and mean velocity in the basilar artery were significantly decreased. CBF exhibited significant decreases in the left putamen/cerebellum crus1/vermis and right thalamus/inferior temporal gyrus, while significant increases were observed in the left postcentral gyrus/precuneus and right middle cingulate gyrus/superior frontal gyrus. In Test 3 vs. Test 1, the basilar artery velocity returned to the baseline level, while CBF continued to decrease. The mean global CBF showed a decreasing trend from Test 1 to Test 3. Furthermore, the mean global CBF had a negative correlation with the systolic pressure, pulse pressure, and mean arterial pressure. The decrease in CBF after reoxygenation may underlie the neurological symptoms in subjects returning to the lowlands. Increased blood pressure could serve as a predictor of a decrease in CBF.

Consistent differences in brain structure and functional connectivity in high-altitude native Tibetans and immigrants.

It has been well-established that high-altitude (HA) environments affect the human brain; however, the differences in brain structural and functional networks between HA natives and acclimatized immigrants have not been well clarified. In this study, native HA Tibetans were recruited for comparison with Han immigrants (average of 2.3 ± 0.3 years at HA), with lowland residents recruited as controls. Cortical gray matter volume, thickness, and functional connectivity were investigated using magnetic resonance imaging data. In addition, reaction time and correct score in the visual movement task, hematology, and SpO2 were measured. In both Tibetans and HA immigrants vs. lowlanders, decreased SpO2, increased hematocrit and hemoglobin, and increased reaction time and correct score in the visual movement task were detected. In both Tibetans and HA immigrants vs. lowlanders, gray matter volumes and cortical thickness were increased in the left somatosensory and motor cortex, and functional connectivity was decreased in the visual, default mode, subcortical, somatosensory-motor, ventral attention, and subcortical networks. Furthermore, SpO2 increased, hematocrit and hemoglobin decreased, and gray matter volumes and cortical thickness increased in the visual cortex, left motor cortex, and right auditory cortex in native Tibetans compared to immigrants. Movement time and correct score in task were positively correlated with the thickness of the visual cortex. In conclusion, brain structural and functional network difference in both Tibetan natives and HA immigrants were largely consistent, with native Tibetans only showing more intense brain modulation. Different populations acclimatized to HA develop similar brain mechanisms to cope with hostile HA environmental factors.

Hypoxic White Matter Injury and Recovery After Reoxygenation in Adult Mice: Magnetic Resonance Imaging Findings and Histological Studies.

Cognitive dysfunction and brain white matter (WM) injury have been found in adults exposed to hypoxia. However, the mechanisms underlying these impairments remain unclear, and moreover, it is also unclear whether these impairments are reversible after reoxygenation. In this study, adult male mice were exposed to hypoxia for 15 days at a simulated altitude of 4300 m and then reoxygenated for 2 months. Control mice were raised under normoxic conditions. Mice showed a significant decrease in arterial oxygen saturation (SaO2) and an increase in heart rate and breath rate after hypoxic exposure, and they displayed anxiety-like emotion and impaired cognitions. Hypoxic mice showed decreased brain WM fractional anisotropy (FA) and increased mean diffusion (MD) mainly in the corpus callosum and internal capsule. The reason for the adult brain WM injury was myelin rather than axon. Further, the myelin injury was due to the obstruction of oligodendrocyte precursor cells (OPCs) differentiation and eventually led to behavioral deficits. More importantly, the changes in physiological indicators, behavioral disorders, and WM injury caused by hypoxia can be recovered after reoxygenation. Taken together, our data indicate that adult brain WM injury caused by hypoxia is reversible after reoxygenation and enhancing OPCs differentiation may be a promising therapy for clinical hypoxic diseases associated with brain injury. Schematic diagram of brain WM and behavioral changes induced by hypoxia/reoxygenation in adult mice.

Resting-State Neuronal Activity and Functional Connectivity Changes in the Visual Cortex after High Altitude Exposure: A Longitudinal Study.

Damage to the visual cortex structures after high altitude exposure has been well clarified. However, changes in the neuronal activity and functional connectivity (FC) of the visual cortex after hypoxia/reoxygenation remain unclear. Twenty-three sea-level college students, who took part in 30 days of teaching at high altitude (4300 m), underwent routine blood tests, visual behavior tests, and magnetic resonance imaging scans before they went to high altitude (Test 1), 7 days after they returned to sea level (Test 2), as well as 3 months (Test 3) after they returned to sea level. In this study, we investigated the hematological parameters, behavioral data, and spontaneous brain activity. There were significant differences among the tests in hematological parameters and spontaneous brain activity. The hematocrit, hemoglobin concentration, and red blood cell count were significantly increased in Test 2 as compared with Tests 1 and 3. As compared with Test 1, Test 3 increased amplitudes of low-frequency fluctuations (ALFF) in the right calcarine gyrus; Tests 2 and 3 increased ALFF in the right supplementary motor cortex, increased regional homogeneity (ReHo) in the left lingual gyrus, increased the voxel-mirrored homotopic connectivity (VMHC) value in the motor cortex, and decreased FC between the left lingual gyrus and left postcentral gyrus. The color accuracy in the visual task was positively correlated with ALFF and ReHo in Test 2. Hypoxia/reoxygenation increased functional connection between the neurons within the visual cortex and the motor cortex but decreased connection between the visual cortex and motor cortex.

Targeting ferroptosis with miR-144-3p to attenuate pancreatic ß cells dysfunction via regulating USP22/SIRT1 in type 2 diabetes.

BACKGROUND: Recently, ferroptosis has been implicated in the pathologic process of several diseases including type 2 diabetes mellitus (T2DM). However, molecular mechanisms underlying ferroptosis in T2DM remain obscure. METHODS: Twenty four mice were included in this study. T2DM model mice were established by a high-fat diet combined with streptozotocin injection. INS-1 cells were stimulated with high glucose (HG). Cell viability was detected by CCK-8 kit. The levels of GSH, MDA, iron, and lipid ROS, and SOD activity, were detected by the corresponding kits. The interaction between miR-144-3p and USP22 was validated by dual-luciferase reporter assay. The relationship between USP22 and its substrate was verified using Co-IP and ubiquitination assays. The mRNA and protein expressions were examined by RT-qPCR and western blot, respectively. The functions of ß cells in vitro and in vivo were evaluated glucose-stimulated insulin secretion test and HOMA-ß, respectively. RESULTS: Ferroptosis occurred in the pancreas of T2DM mice and HG-induced INS-1 cells. Silencing miR-144-3p blocked the effect of HG on the cell viability and accumulation of lipid peroxides, thereby improving the insulin secretion in INS-1 cells. Mechanistically, USP22 is a direct target of miR-144-3p, which could stabilize SIRT1 expression, thereby suppressing ferroptosis. Overexpressing USP22 attenuated deleterious roles of HG in INS-1 cells; but its roles were reversed by up-regulating miR-144-3p. In vivo study demonstrated that miR-144-3p antagomir exerted an anti-hyperglycemic effect and regulated the ferroptosis-related proteins in the pancreas. CONCLUSION: The up-regulation of miR-144-3p suppressed USP22/SIRT1 to induce ferroptosis, which causes pancreatic ß cells dysfunction, thereby promoting T2DM development.

Exploration of the Molecular Mechanisms of Hyssopus cuspidatus Boriss Treatment of Asthma in an mRNA-miRNA Network via Bioinformatics Analysis.

Hyssopus cuspidatus Boriss (H. cuspidatus) is a traditional Chinese medicine commonly used in the treatment of asthma. In the present study, we applied bioinformatics techniques for mRNA-miRNA profiling to elucidate the potential mechanisms of H. cuspidatus in asthma treatment. Bioactive compounds from H. cuspidatus, potential therapeutic targets of H. cuspidatus, and asthma-related targets were identified from the literature and databases. The intersection of H. cuspidatus-related targets and asthma-related targets was identified using the STRING platform. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed using the Metascape platform. Networks were constructed from these nodes using Cytoscape. The results showed that 23 active compounds were identified in H. cuspidatus, sharing 122 common asthma-related targets. Moreover, 43 miRNAs regulating 19 key targets involved in the antiasthmatic effects of H. cuspidatus were identified. Further analysis of biological pathways, active compound-key target-pathway network, and active compound-key target-miRNA network indicated that the antiasthmatic effects of H. cuspidatus mainly occurred through caffeic acid, methyl rosmarinate, luteolin, esculetin, and 8-hydroxycirsimaritin. These compounds interacted with multiple miRNAs, including miR-99a, miR-498, miR-33b, and miR-18a, regulating multiple genes, including JAK, STAT3, EGFR, LYN, and IL-6, in multiple pathways, including those involved in the regulation of JAK-STAT signaling, EGFR tyrosine kinase inhibitor resistance, PI3K-Akt signaling, and inflammation. In summary, we have elucidated the potential mechanisms of H. cuspidatus treatment of asthma from a systemic and holistic perspective through analysis of compound-mRNA-miRNA interaction. Our study should provide new insights for further research on H. cuspidatus treatment of asthma.

Correlation of Blood Biochemical Markers with Tardive Dyskinesia in Schizophrenic Patients.

Objective: Oxidative stress factors and proinflammatory cytokines had been found to be involved in the pathogenesis of patients with tardive dyskinesia (TD). This study assumes that blood biochemical markers would have a link with TD in schizophrenia patients. To explore the correlation between blood biochemical markers and tardive dyskinesia in patients with schizophrenia (SCH). Methods: From January 2010 to August 2021, the inpatients who met the diagnostic criteria of schizophrenia in the Chinese Classification and Diagnosis Criteria of Mental Disorders (DSM-4) and the American Diagnostic and Statistical Manual of Mental Disorders (DSM-4) were followed up in the psychiatric outpatient department of Jinxia Street Community Health Service Center, Longhu District, Shantou City. The diagnostic criteria of Abnormal Involuntary Movement Scale (AIMS) used in the TD study of Schooler and Kane were used to screen the patients. Patients were divided into the schizophrenia (SCH group) and the schizophrenia with TD groups (TD group). Oxidative stress factors including Superoxide Dismutase1 (SOD1), Glutathione Peroxidase1 (GPX1), Malondialdehyde1 (MDA1), Catalase Activity1 (CAT1), and brain-derived neurotrophic factor 1 (BDNF1) and some inflammatory cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), serum tumor necrosis factor (TNF-α), prolactin, estrogen, and cortisol were measured in 121 schizophrenic patients with tardive dyskinesia and 118 schizophrenic patients. The correlation analysis was conducted on the data. Results: Age and female were immutable risk factors for the development of TD, and there were significant differences in blood biochemical indices GPX1, MDA1, CAT1, and TNF-α in schizophrenic patients with and without TD. Conclusion: This study supports that oxidative stress and immune disorders are associated with TD patients. Blood biochemical markers GPX1, MDA1, CAT1, and TNF-α may play an important role in the pathogenesis of schizophrenia combined with TD patients, and they may be useful in the diagnosis of schizophrenia with tardive dyskinesia.

Systematic review and meta-analysis of the CT imaging characteristics of infectious pneumonia.

BACKGROUND: Since December 2019, there have been cases of infectious pneumonia of unknown cause in Wuhan, Hubei Province, China. On January 12, 2020, the World Health Organization (WHO) named it COVID-19. There are few studies on the clinical characteristics of patients with COVID-19, and results vary widely in sample sizes. METHODS: Chinese and English databases were searched with "Infectious pneumonia", "COVID-19", "CT", "SARS-COV-2", and "Diagnose" as keywords. Rev Man 5.3 software provided by the Cochrane system was used to assess the quality of the included literature. RESULTS: Of the 18 included studies, ground-glass shadow was the most common computed tomography (CT) sign [95% confidence interval (CI): 0.79-0.97], followed by thickening of the blood vessels (95% CI: 0.63-0.78), and pleural thickening (95% CI: 0.02-0.15). Of the 18 studies, 12 reported that the lesions were externally subpleural (95% CI: 0.132-0.173), and 6 reported that the lesions were distributed in a single lobe (95% CI: 0.598-0.841). The heterogeneity test results showed that the morphology of the lesions was cord-like (95% CI: 0.092-0.172), grid-like (95% CI: 0.152-0.193), patchy (95% CI: 0.192-0.313), and nodular (95% CI: 0.591-0.745). DISCUSSION: Ground-glass opacity was a typical CT manifestation for patients with infectious pneumonia, and CT signs were instrumental in diagnosing this disease.

Electrophysiological mechanisms underlying hypoxia-induced deficits in visual spatial and non-spatial discrimination.

Impaired visual cognition in residents of hypoxic environment has been widely reported; however, the underlying electrophysiological mechanisms remain unclear. In this study, 23 college students underwent three sessions of a Clock task test before a 30-day high-altitude exposure (Test 1) and 1 week (Test 2) and 3 months (Test 3) after they returned to lowlands. The Clock task consists of a visual spatial angle and a visual non-spatial color discrimination subtask. Simultaneously, electroencephalography (EEG) was recorded during the Clock task. The behavioral results showed that, compared with Test 1, accuracy in Test 2 was significantly decreased in both the Angle and Color tasks, and reaction time (RT) was significantly increased in the Angle task. The event-related potentials results showed that, during both tasks amplitudes of the occipital N1 and P3 components during both tasks were significantly decreased in Test 2, compared with Test 1. Moreover, N1 amplitude was negatively correlated with RT and positively correlated with accuracy. Further time-frequency EEG analysis showed that theta power at occipital sites was significantly decreased in both tasks in Test 2, compared with Test 1, and was negatively correlated with RT in the Angle task. In Test 3, both the behavioral performance and EEG activity recovered to the baseline level in Test 1. These findings suggested that hypoxia impairs both visual spatial and visual non-spatial discriminations, and these impairments can recover after subjects return to lowlands. Inhibition of brain electrophysiological activity in the visual cortex may explain the deficits in visual cognition.

Correlation between obstructive sleep apnea hypopnea syndrome and hypertension: a systematic review and meta-analysis.

BACKGROUND: Obstructive sleep apnea hypopnea syndrome (OSAHS) is defined as more than 30 recurrent episodes of apnea or a sleep apnea hypopnea index (AHI) of more than 5 times/hour at a night. It is more common in people over 40 years old and is more prevalent in men. The pathogenesis factors and correlations of OSAHS are worth studying. METHODS: A literature search was performed in the PubMed, Embase, and Ovid-Medline databases from the date when the database was established to April 2021. Keywords included obstructive sleep apnea hypopnea syndrome, sleep apnea hypopnea syndrome, hypertension, and correlation. RESULTS: Eight articles involving 3,484 OSAHS patients were included. Analysis results showed that OSAHS was correlated with hypertension [odds ratio (OR) =6.44, 95% confidence interval (CI): 5.38-7.71, P<0.00001]. The severity of OSAHS revealed that the correlation of hypertension to mild, moderate, and severe OSAHS showed OR =1.93, 95% CI: 0.69-5.43, P=0.21, OR =0.43, 95% CI: 0.24-0.74, P=0.0003, and OR =0.85, 95% CI: 0.42-1.73, P=0.66, respectively. The results indicated that mild, moderate, and severe OSAHS are risk factors for hypertension. DISCUSSION: Eight articles were included to determine the correlation between OSAHS and hypertension. It was found that OSAHS was closely correlated with hypertension, and they may be risk factors for each other.

JAX2, an ethanol extract of Hyssopus cuspidatus Boriss, can prevent bronchial asthma by inhibiting MAPK/NF-κB inflammatory signaling.

BACKGROUND: Hyssopus cuspidatus Boriss has been used to treat bronchial asthma for many years in Uighur medicine. JAX2, an ethanol extract from this plant, has effectiveness against bronchial asthma. However, the molecular basis for the anti-inflammatory effects of JAX2 remains unclear. PURPOSE: This study aimed to evaluate the mechanism of JAX2 against bronchial asthma. METHODS: We established an asthma model in rats using ovalbumin (OVA), and an inflammatory model in RAW264.7 cells using lipopolysaccharide (LPS) stimulation. To evaluate the anti-inflammatory effects of JAX2, the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-17, eotaxin and immunoglobulin (Ig)E were measured by enzyme-linked immunosorbent assay (ELISA). Cell viability was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium, inner salt (MTS) assay. Further, nitric oxide (NO) and reactive oxygen species (ROS) were determined using Griess reagent and 2,7-dichlorofluorescein diacetate. The phosphorylation of p-extracellular signal-regulated kinase (ERK), p-Jun-NH2-terminal kinase (JNK), p38 kinases (p38) and p-inhibitor of nuclear factor kappa-B kinase (IKK), and nuclear translocation of p-p65 kinases (p-p65) were determined by immunofluorescence to uncover the effects of JAX2 on the Mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. RESULTS: After JAX2 administration to rats, Interferon (IFN)-γ concentrations in BALF increased significantly. Further, the concentrations of TNF-α, IL-4, IL-6, IL-17 and eotaxin in BALF, and IgE in serum decreased. JAX2 decreased TNF-α, IL-6 and NO in cell supernatant, and reduced ROS intracellularly. Concurrently, IFN-γ concentrations increased in cell supernatant significantly. In LPS-induced RAW264.7 cells, JAX2 inhibited phosphorylation of p-ERK, p-JNK and p-38 MAPK. The subsequent phosphorylation of p-IKK and nuclear translocation of the p-p65 subunit of NF-κB were also suppressed. CONCLUSION: Based on these findings, we believe that JAX2 has both preventive and treatment effects in bronchial asthma. Furthermore, in the RAW264.7 cell inflammatory model, JAX2 also inhibited NF-κB and MAPK signaling pathways.

Brain grey matter volume reduction and anxiety-like behavior in lipopolysaccharide-induced chronic pulmonary inflammation rats: A structural MRI study with histological validation.

While there have been multiple fMRI studies into the brain functional changes after acutely stimulated peripheral infection, knowledge for the effect of chronic peripheral infection on whole brain morphology is still quite limited. The present study was designed to investigate the brain structural and emotional changes after peripheral local infection initiated chronic systemic inflammation and the relationship between circulating inflammatory markers and brain grey matter. Specifically, in-vivo T2-weighted MRI was performed on rats with lipopolysaccharide (LPS)-induced chronic pulmonary inflammation (CPI) and those without. Grey matter volume was quantified using diffeomorphic anatomical registration through exponentiated lie (DARTEL) enhanced voxel-based morphometry followed by between-group comparison. Open field experiment was conducted to test the potential anxiety-like behaviors after CPI, along with the ELISA estimated inflammatory markers were correlated to grey matter volume. Guided by image findings, we undertook a focused histological investigation with immunefluorescence and Nissl staining. A widespread decrease of grey matter volume in CPI-model rats was revealed. 8 of the 12 measured inflammatory markers presented differential neuroanatomical correlation patterns with three of the pro-inflammatory cytokines (IL-1ß, IL-6 and TNF-α) and CRP being the most notable. Lower grey matter volumes in some of the inflammatory markers related regions (amygdala, CA2 and cingulate cortex) were associated with more-severe anxiety-like behaviors. Furthermore, grey matter volumes in amygdala and CA3 were correlated negatively with the expressions of glial proteins (S100ß and Nogo-A), while the grey matter volume in hypo-thalamus was changing positively with neural cell area. Overall, the neuroanatomical association patterns and the histopathology underpinning the MRI observations we demonstrated here would probably serve as one explanation for the cerebral and emotional deficits presented in the patients with CPI, which would furthermore yield new insights into the adverse effects the many other systemic inflammation and inflammatory autoimmune diseases would pose on brain morphology.

Regional cerebral blood flow in natives at high altitude: An arterial spin labeled MRI study.

BACKGROUND: It is known that a neurologic sequence occurs at high altitudes (HA); hence, cerebral blood flow (CBF) might vary by altitude. PURPOSE: To use arterial spin labeled (ASL) MRI to evaluate absolute CBF differences between subjects who live at HA and lowlands. STUDY TYPE: Cohort prospective trial. POPULATION: In all, 64 HA Tibetans, 19 lowland Tibetans, and 25 lowland Han subjects. FIELD STRENGTH/SEQUENCE: CBF was measured with the pulsed ASL sequence at 3T. ASSESSMENT: CBF was correlated with abode altitude in HA Tibetans; CBF differences among HA Tibetans, lowland Tibetans, and lowland Han subjects was assessed. STATISTICAL TESTS: Pearson correlation assessed the correlation. Independent t-tests analyzed group differences. RESULTS: In HA Tibetans, CBF decreased with altitude in the bilateral anterior and posterior cingulate gyri, fusiform gyrus, cerebellar tonsil and cortices, and thalamus as well as left middle and inferior temporal gyri and right insula (P < 0.05); HA Tibetans (vs. lowland Tibetans) had lower CBF in the left hemisphere (precuneus, anterior cingulate gyrus, fusiform gyrus, and lingual gyrus) and right hemisphere (superior parietal lobule, precuneus, posterior cingulate gyrus, and cerebellar tonsil), while they had higher CBF in the left inferior parietal lobule, lentiform nucleus, and inferior frontal gyrus (P < 0.05). The overlapping regions, in which CBF in HA Tibetans correlated with altitude and decreased (vs. lowland Tibetans), were selected for region of interest analysis, and the results showed lower CBF in HA Tibetans than lowland Han subjects (P < 0.05). DATA CONCLUSION: HA adaptation in Tibetans is associated with a decrease of regional CBF. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018.