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Objective:To investigate the application effect of flipped classroom combined with micro-lectures in the teaching of pediatric infectious diseases.Methods:A total of 199 five-year students in the class of 2019 from Department of Pediatrics of Chongqing Medical University were divided into 14 groups. Each group selected a micro-lecture theme targeting the key and difficult points of the course and produced an original micro-lecture video through flipped classroom, which was then uploaded to Chaoxing platform for evaluation by teachers and students. At the end of the course, a questionnaire survey was performed to investigate the teaching effect, and final examination score and department examination score during internship were compared between the students in the class of 2019 and those in the class of 2018. SPSS 22.0 was used to perform the t-test, the Wilcoxon rank-sum test, the chi-square test, and the Fisher's exact test. Results:A total of 14 flipped micro-lecture works were completed by the students. The questionnaire survey showed that 98.47% (193/196) of the students thought that this model was helpful to master the key and difficult points; 93.88% (184/196) of the students thought that the flipped micro-lecture works had better originality and quality than reading reports and literature reviews in the past; 94.90% (186/196) of the students were more willing to accept the mode of flipped classroom combined with micro-lectures. Compared with the students in the class of 2018, the students in the class of 2019 had significantly higher final examination score (79.32±7.53 vs. 76.06±12.01, P<0.001), theoretical score of department examination (88.68±4.87 vs. 87.15±4.09, P<0.001), and operation score of department examination (84.93±7.56 vs. 82.08±9.10, P<0.001). Conclusion:Flipped classroom combined with micro-lectures can effectively solve the key and difficult points in the teaching of pediatric infectious diseases, and it can also stimulate the interest in independent learning and help to improve learning performance among students. Therefore, it holds promise for clinical application.
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BackgroundTo clarify the characteristic and the duration of positive nucleic acid in children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including asymptomatic children. MethodsA total of 32 children confirmed with SARS-CoV-2 infection between January 24 and February 12, 2020 from four provinces in Western China were enrolled in this study and followed up until discharge and quarantine 14 days later. ResultsEleven children (34%) were asymptomatic, among whom six children had normal computed tomographic (CT) scan images. Age and gender were not associated with clinical symptoms or the results of CT scan in children infected with SARS-CoV-2. The concentrations of white blood cells and neutrophils were higher in children with asymptomatic infection than in children with clinical symptoms or CT abnormalities. Patients who presented with CT abnormalities had lower D-dimer or lower total bilirubin than those who had normal CT scan but clinical symptoms. All children recovered and no one died or was admitted to the pediatric intensive care unit (PICU). The mean duration of positive SARS-CoV-2 nucleic acid was 15.4 (SD=7.2) days and similar for both asymptomatic children and children with symptoms or CT abnormalities. We found a significant negative correlation between the lymphocyte count and the duration of positive nucleic acid test. ConclusionsChildren with asymptomatic infection should be quarantined for the same duration as symptomatic patients infected with SARS-CoV-2. The clinical significance and mechanism behind the negative correlation between the number of lymphocytes and the duration of positive SARS-CoV-2 needs further study.
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Objective To identify the role of IL-17A during respiratory syncytial virus (RSV) in-fection in a mouse model. Methods Female wild-type C57BL/6 mice and IL-17A knockout ( IL-17A-/-) mice at the age of 6 to 8 weeks were both randomly divided into two groups:control and RSV groups. Mice in the control groups were given the supernatant of Hep-2 cell culture, while those in the RSV groups were treated with RSV A2 through intranasal administration. Leukocytes in bronchoalveolar lavage fluid ( BALF) samples were counted. Left lung tissues were stained with hematoxylin and eosin ( HE ) to evaluate his-topathological scores. Airway hyperresponsiveness ( AHR) was measured by whole-body plethysmography. The concentrations of IFN-γ were determined with ELISA. RSV titers were measured by plaque assay. To assess the effects of IL-17A on IFN-γproduction and its role in RSV infection, IL-17A-/- mice were treated with exogenous recombinant murine IFN-γ or IL-17A, while wild-type mice were given IFN-γ neutralizing antibody intervention. Results The counts of inflammatory cells and neutrophils in BALF, lung tissue his-topathological scores, AHR, IFN-γlevels and virus titers of the wild-type group were higher than those of the IL-17A-/-group after RSV infection. IFN-γlevels, inflammatory cell counts in BALF, AHR and lung tissue histopathological scores were significantly increased in RSV-infected IL-17A-/- mice after the intervention of recombinant murine IL-17A or IFN-γ. RSV titers were much higher in the recombinant murine IL-17A-trea-ted group, but not affected by the recombinant murine IFN-γ intervention. Inflammatory cell counts in BALF, AHR and lung tissue histopathological scores were significantly decreased in RSV-infected wild-type mice following IFN-γ neutralizing antibody treatment, but no significant changes were found in RSV titers. Conclusions IL-17A might be involved in the pathogenesis of pulmonary diseases during RSV infection through promoting IFN-γ production and inhibiting viral clearance in mice.
ABSTRACT
Objective@#To identify the role of interferon (IFN)-γ during respiratory syncytial virus (RSV) re-infection in mice.@*Method@#Female wild type C57BL/6 mice and IFN-γ knockout mice (IFN-γ-/- mice) at the age of 6 to 8 weeks were randomly divided into two groups: control group and RSV group, according to random number table.Each group was further divided into primary infection group and re-infection group.There were 8 groups.Mice were sacrificed on days 5, 7, 14 to collect samples.There were 5-8 mice in each group at each time point.And experiment was repeated twice. Leukocytes in bronchoalveolar lavage fluid (BALF) were counted, left lung tissues were stained with HE and histopathological scoring (HPS) was performed.The concentrations of IFN-γ, IL-5, IL-13 were determined with ELISA.T test or single factor analysis of variance was used to compare between groups.@*Result@#(1) Mice infected or reinfected with RSV showed pale hair, weight loss, decreased activity and anorexia.(2) IFN-γ levels significantly increased on days 5 and 7 following RSV primary infection and reinfection as compared to control groups in wild type mice ((192±44) vs.(36±8) and (531±161) vs.(23±4) pg/ml on day 5, (100±23) vs.(36±8) and (862±186) vs.(23±4) pg/ml on day 7, t=2.654, 2.513, 2.654, 3.968, all P<0.05). (3) Compared to the RSV-reinfected IFN-γ-/- mice, RSV-reinfected wild type mice had less body weight loss ((13.6±2.6)% vs.(22.7±2.9)% on day 5, (18.0±3.1)% vs.(26.5±1.8)% on day 7, t=2.314, 2.308, both P<0.05), lower lung tissue histopathological score ((1.50±0.09) vs.(2.07±0.11) on day 5, (1.53±0.11) vs.(2.08±0.09) on day 7, (1.10±0.06) vs.(1.59±0.08) on day 14, t=3.916, 3.890, 4.837, all P<0.01), less BALF inflammatory cells count ((11.6±2.0) vs.(44.2±10.6)×105/ml on day 5, (18.2±3.9) vs.(38.3±2.2)×105/ml on day 7, t=2.818, 4.786, both P<0.05), and lower levels of IL-5 and IL-13 ((24±3) vs.(148±23), (23±4) vs.(169±26) pg/ml on day 5, (30±8) vs.(233±44), (20±5) vs.(182±19) pg/ml on day 7, (91±6) vs.(129±19), (62±8) vs.(132±5) pg/ml on day 14, t=5.252, 5.445, 4.517, 7.326, 3.816, 7.577, all P<0.01).@*Conclusion@#IFN-γ can alleviate airway inflammation following RSV reinfection in mice.
