1.Effect of calcitonin gene-related peptide on the expression of triggering receptor expressed on myeloid cells-1 in lipopolysaccharide-induced macrophages
Yunchao LI ; Chaxiang GUAN ; Yang ZHOU ; Guoying SUN ; Meng SHI ; Jing WU ; Wenjie LI
Journal of Central South University(Medical Sciences) 2010;35(2):100-106
Objective To determine the effect of calcitonin gene-related peptide (CGRP) on triggering receptor expressed on myeloid cells-1 (TREM-1) in the lipopolysaccharide (LPS)-induced macrophages and its signal transduction pathway. Methods The levels of TREM-1 mRNA in the macrophages were observed by reverse transcription-polymerase chain reaction (RT-PCR), and flow cytometry was performed to detect TREM-1 protein expression levels in the macrophages. Results CGRP had no regulating effect on the expression of TREM-1 in the macrophages; LPS could up-regulate macrophages to express TREM-1; CGRP increased TREM-1 mRNA expression in LPS-induced macrophages in dose and time-dependent manner; CGRP increased TREM-1 protein expression in LPS-induced macrophages, which could be partially reversed by H-7 or H-89 (P<0.05). Conclusion CGRP can regulate the LPS-induced macrophages synthesis and secretion of TREM-1, and the intracellular signal transduction pathway is related to PKA and PKC.
2.Comparison of students' self-evaluated learning behavior and achievement between online and offline problem-based learning
Ming JI ; Yangting XU ; Yang HAN ; Dandan FENG ; Chaxiang GUAN ; Ziqiang LUO
Chinese Journal of Medical Education Research 2023;22(11):1661-1665
Objective:To compare the self-evaluated learning behavior and achievement of eight-year-program clinical medical students on online and offline problem-based learning (PBL), and to provide references and suggestions for successful implementation of online PBL teaching.Methods:During the three semesters of September 2020 to January 2022, a survey was performed on 100 clinical medical students of 2018 eight-year program on online or offline PBL teaching in Xiangya School of Medicine, Central South University. At the end of PBL courses, the students received questionnaires to self-assess their learning behavior and achievement in online or offline PBL teaching. The data were analyzed using the paired rank sum test with the use of SPSS 26.0.Results:Before class, there were no significant differences in learning behaviors including preparation time, communication with classmates, and materials collecting and sorting between students on online and offline PBL teaching ( P>0.05). In class, no significant differences were found in students' initiative of speaking and degree of satisfaction with classmates' speaking between online and offline teaching ( P>0.05), but the students on offline teaching showed significantly better concentration of attention ( Z=-4.24, P<0.001), listening to classmates' speeches ( Z=-3.42, P=0.001), and classmates' interaction ( Z=-3.11, P=0.002) compared with those on online teaching. No significant differences were observed between online and offline PBL teaching in students' self-evaluated learning achievements including improvements in autonomous learning ability, problem-solving ability, and literature inquiry skills ( P>0.05). Conclusion:Students on online PBL teaching have generally as good pre-class preparation and in-class learning performance as those on offline PBL teaching, indicating that the online PBL mode can be well implemented, and it can also ensure almost the same learning achievement as offline teaching.
3.Cloning and expression and preliminary antigenicity identification for the diagnostic antigen of hepatitis E virus
Li WAN ; Qiudong SU ; Yao YI ; Shengli BI ; Chaxiang GUAN
Chinese Journal of Epidemiology 2015;36(3):275-279
Objective To clone,express and purify thioredoxin (named as N5),a specific diagnostic antigen of hepatitis E virus (HEV),and to initially evaluate its antigenicity and serological test performance.Methods Based on the gene sequences of HEV-ORF2 and carboxyl terminal ORF3 on GenBank,the codon was optimized by the Escherichia coli codon preference,inserted it into prokaryotic expression vector M48 following total gene synthesization,and expressed in Escherichia coli fusion protein N5 recombined with Thioredoxin (TRX).Fusion protein was purified in affinity chromatography,evaluating its antigenicity with Western blot technology,then evaluating its serological test performance using the negative and positive serum samples confirmed of HEV infection with laboratory and clinical tests.Results The recombinant plasmid expressing N5 diagnostic antigen was successfully established; high-level expression and purification to obtain soluble diagnostic antigens; Western blot results indicating fusion protein N5 can be bound specifically with the serum of HEV IgM antibody positive,showing satisfactory antigencity; using fusion protein N5 as the capture antigen to build indirect ELISA,testing 40 serum samples of HEV cases confirmed by pathogen detection and clinical diagnosis and 40 serum samples of healthy people,with the sensitivity and specificity of 95% (38/40) and 90% (36/40) respectively.Conclusion Recombinant plasmid expressing the HEV diagnostic antigen recombined with thioredoxin was successfully established,and soluble fusion protein N5 was obtained with high expression and strong antigenicity,promising in its future applications.
4.Aucubin alleviates lipopolysaccharide-induced acute lung injury in mice.
Bingbing PAN ; Yong ZHOU ; Gaoyin KONG ; Ping LI ; Qulian GUO ; Chaxiang GUAN
Journal of Central South University(Medical Sciences) 2019;44(2):128-133
To investigate the effect of prophylactic aucubin (AU) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.
Methods: Male BABL/c mice were randomly divided into a control group, an ALI group, and an AU treatment group, 16 mice in each group. ALI mice were injected with LPS (5 mg/kg, intratracheal injection), and AU (10 mg/kg) was injected intraperitoneally 30 min ahead. After LPS injection for 6 hours mice were sacrificed, the morphological changes of lung tissues were detected by HE staining and the lung injury score was obtained. The mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin 10 (IL-10) in lung tissue was detected by real-time PCR. The total protein and lactate dehydrogenase (LDH) activity, the cell count, and the protein content of TNF-α and IL-10 in the mouse bronchoalveolar lavage fluid (BALF) were detected.
Results: Compared with ALI mice, the pathological damage score of lung tissue was significantly reduced in the AU group, the total number of BALF cells, neutrophils, and macrophages were significantly decreased, LDH activity and the total protein content were also significantly decreased (all P<0.01). In addition, AU can reduce the mRNA and protein expression of TNF-α in lung of ALI mice, and increase the mRNA and protein expression of IL-10 (all P<0.01).
Conclusion: AU can reduce LPS-induced ALI in mice.
Acute Lung Injury
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chemically induced
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Animals
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Bronchoalveolar Lavage Fluid
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Iridoid Glucosides
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Lipopolysaccharides
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Lung
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Male
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Mice
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Tumor Necrosis Factor-alpha