[Effects of ursolic acid on oxidative stress and inflammatory factors in a rat model of AR after PM2.5 exposure]

Objective: To investigate the effects of ursolic acid (UA) on oxidative stress and inflammatory factors in a rat model of AR after PM2.5 exposure. Methods: Sixty healthy female SD rats were randomly divided into five groups: normal control group (NC group), PM2.5 unexposed AR group (AR group), PM2.5 exposed AR group (ARE group), UA intervention AR group (AR+UA group), and UA intervention PM2.5 exposed AR group (ARE+UA group), with 12 rats in each group. AR model was performed by a basal sensitization with intraperitoneal injection of ovalbumin (OVA) and followed by nasal instillation. PM2.5 exposure was carried out by inhalation exposure system at a concentration of 200 μg/m³ for 3 h/d for 30 days. UA intervention group was given UA intragastric administration at 20 mg/(kg·d). AR symptoms including sneezing, nasal scratching and nasal secretion of rats in each group were observed. The activities of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in nasal mucosa were tested. The pathological changes of nasal mucosa were observed by HE staining. The levels of OVA-sIgE, IL-6 and IL-17 in serum were measured by enzyme-linked immunosorbent assay (ELISA). Protein microarray was used to measure the expression of multiple inflammation cell factors in nasal mucosa. Statistical analysis was performed with SPSS 20.0. Results: After UA intervention, the frequency of nasal sneezing, scratching and nasal secretion in ARE+UA group were lower than those of ARE group (P<0.05). Pathological examination of nasal mucosa showed that ARE+UA group had less inflammatory granulocyte infiltration and less pathological damage to the epithelial layer than ARE group. The activities of SOD in nasal mucosa of ARE+UA group were higher than those of ARE group ((50.10±3.09) U/mg vs (20.13±1.30) U/mg, F value was 597.54, P<0.01). The contents of MDA in nasal mucosa of ARE+UA group were lower than those of ARE group ((57.78±12.36) nmol/g vs (124.12±9.40) nmol/g, F value was 115.51, P<0.01). The expression levels of OVA-sIgE, IL-6 and IL-17 proteins were lower in the ARE+UA group than those in ARE group ((11.61±0.27) ng/ml vs (20.30±0.67) ng/ml, (47.59±15.49) pg/ml vs (98.83±10.98) pg/ml, (623.30±8.75) pg/ml vs (913.32±9.06) pg/ml, F value was 283.42, 80.45, 683.73, respectively, all P<0.01). After UA intervention, protein microarray analysis showed that the expression of IL-4, IL-6, IL-13, chemokine CXCL7, IL-1α, IL-1β, MMP-8 and MCP-1 in ARE+UA group was decreased compared with ARE group while IFN-γ and IL-10 increased (all P<0.01). Conclusion: UA can reduce the aggravated AR symptoms and pathological damage of nasal mucosa, inhibit oxidative stress and release of inflammatory factors after PM2.5 exposure, and thus plays a protective role in the pathological damage of AR induced by PM2.5 exposure.

[Effects of acute paraquat poisoning on cognitive ability in humans]

Objective: To explore the effects of acute paraquat poisoning on cognitive function of patients through neuropsychologic test. Methods: In June 2019, 36 patients with acute paraquat poisoning in the emergency department of a provincial hospital in Hebei Province were selected as the case group. 36 healthy individuals were selected as control group. The cognitive function and depressive state were assessed by mini mental state scale, auditory word learning test, digit span test, connection test, Boston Naming Test and geriatric depression scale. Results: The results of Mini-Mental State examination showed that the total score of the case group was lower than that of the control group, the difference was statistically significant (P<0.05) . The results of the Auditory Vocabulary Learning test showed that the scores of delayed recall, clue recall, corrective ability and semantic learning strategies of the case group were significantly lower than those in the control group (P<0.05) . There was no significant difference in the scores of immediate memory between the two groups (P>0.05) . The scores of Digit Span test and Boston Naming test in the control group were higher than those in the case group, the Trail Making test time in the control group was shorter than that in the case group, and the differences were statistically significant (P<0.05) . Conclusion: Acute paraquat poisoning can impair human cognitive ability to a certain extent.

Autism-associated Dyrk1a truncation mutants impair neuronal dendritic and spine growth and interfere with postnatal cortical development

Autism is a prevailing neurodevelopmental disorder with a large genetic/genomic component. Recently, the dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1 A (DYRK1A) gene was implicated as a risk factor for autism spectrum disorder (ASD). We identified five DYRK1A variants in ASD patients and found that the dose of DYRK1A protein has a crucial role in various aspects of postnatal neural development. Dyrk1a loss of function and gain of function led to defects in dendritic growth, dendritic spine development and radial migration during cortical development. Importantly, two autism-associated truncations, R205X and E239X, were shown to be Dyrk1a loss-of-function mutants. Studies of the truncated Dyrk1a mutants may provide new insights into the role of Dyrk1a in brain development, as well as the role of Dyrk1a loss of function in the pathophysiology of autism.

Simulation of water entry of a wedge through free fall in three degrees of freedom

The water entry problem of a wedge through free fall in three degrees of freedom is studied through the velocity potential theory for the incompressible liquid. In particular, the effect of the body rotation is taken into account, which seems to have been neglected so far. The problem is solved in a stretched coordinate system through a boundary element method for the complex potential. The impact process is simulated based on the time stepping method. Auxiliary function method has been used to decouple the mutual dependence between the body motion and the fluid flow. The developed method is verified through results from other simulation and experimental data for some simplified cases. The method is then used to undertake extensive investigation for the free fall problems in three degrees of freedom.