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Objective:To explore the role of blended learning in the undergraduate teaching of Clinical Biochemistry. Methods:The Batch 2017 medical laboratory technology undergraduates ( n=134) were selected as research objects, and the effect and opinions of blended learning were statistically analyzed by questionnaire survey and online-offline platform data. SPSS 23.0 was used to conduct rank sum test. Results:The application of blended learning in the Clinical Biochemistry teaching affected the learning effect in an all-round way. The average score increased from 70 (64, 76) to 79 (71, 85), with statistical difference ( Z=6.69, P<0.001). Conclusion:The combined application of blended learning, problem-based learning, flipped classroom and formative assessment is conducive to teaching students in accordance with their aptitude and cultivating students' clinical thinking ability.
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<p><b>OBJECTIVE</b>To develop a mouse model for acute otitis media (AOM) via transbullar injection method and evaluate its feasibility and practicability.</p><p><b>METHODS</b>The middle ears (ME) of C57BL/6 mice were inoculated via transbullar injection method with 5 µl streptococcus pneumoniae (S.pn) 19F suspension (1×10(7) CFU/ml), and the control group was inoculated equivalent phosphate buffered solution (PBS). Behavior changes were observed daily following inoculation. The ME tissues for histological examination and the middle ear lavage fluid (MELF) for total cells quantification, S.pn load determination and cytokines measurement were collected at 12 h, day 1, 2, 3, 5, 7 after inoculation, respectively.</p><p><b>RESULTS</b>Within 24 hours after instillation, the density of S.pn and the level of acute inflammatory cytokines in ME cavity increased rapidly, some mucosal hyperplasia was evident and leukocytic infiltration (primarily neutrophils) began. The level of ME inflammatory response reached maximal at 2-3 days after inoculation, with extensive effusion, leukocytic infiltration and mucosal thickening. Meanwhile, the density of S.pn decreased gradually. Bacterial clearance was completed by day 5 with extensive resolution of ME inflammation, although mucosal hyperplasia did not resolute until day 7.</p><p><b>CONCLUSION</b>A mouse model for AOM is successfully established via transbullar injection method, laying foundation for future study of AOM.</p>
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Animals , Mice , Acute Disease , Cytokines , Disease Models, Animal , Ear, Middle , Injections , Mice, Inbred C57BL , Otitis Media , Otitis Media with EffusionABSTRACT
Objective To lay the foundation for further exploration on parasitifer's defence reaction to pneumolysin through constructing ply gene-deletion strain of Streptococcus pneumoniae and researching on its virulence change. Methods A linker fragment with erm gene in middle and homologous upstream and downstream fragment of ply gene at both sides was prepared by long flanking homology-polymerase chain reaction(LFH-PCR). The linker fragment was transformed into Streptococcus pneumoniae. ply-deficient strain was then screened out from blood plate which contains erythromycin and identified by PCR. ply-deficient strain growth in vitro was observed and virulence change was observed through infecting mouse model. Results PCR results showed that ply gene was replaced completely by erm gene. The ply deficient strain was successfully constructed. The growth of single strain culture medium showed that ply genetic defect made no influence on bacterial's external growth. While in the mice nasal cavity infecting experiment, deficient strain enter into blood after 6 h from infecting which obviously slower than that did wild-type(2 h). And the number of bacteria at each point was much smaller than that of wild-type(P ＜0. 01 ). The mice peritonaeum infecting experiment showed that median lethal time of wild-type was 3 d, while that of deficient strain was 18 d(P＜0. 01). Conclusion It is a good way to completely substitute ply gene using LFH-PCR. ply deletion made no influence on baterial's growth in vitro, but it resulting in reduction of bacterial virulence in vivo.
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Objective To evaluate whether immunization with △A146 Ply could confer protections against pneumococcal infections in murine models and to reveal the possible role of △A146 Ply-specific IgG in the protection elicited.MethodsBALB/c mice were immunized intraperitoneally with △A146 Ply or PBS plus alum.Fourteen days after the third immunization,mice were intranasally challenged with serotype 14 and 19F Streptococcus pneumoniae.Three days after inoculation,lungs were removed from mice and homogenized in PBS,followed by plated on red cell plates.Viable bacteria were counted after overnight incubation.As to the sepsis models,vaccinated mice were challenged intraperitoneally with different dosage bacteria of D39 and serotype 3 strain.The numbers of CFU log10 were compared by Mann Whitney U test and survival rates were analyzed using log-rank test.Passive protection was used to evaluate the role of △A146 Ply-specific IgG in the protection against otherwise lethal infection resulted from D39.Results ELISA analysis demonstrated higher titer specific antibody responses to △A146 Ply was produced after 3 times immunization.Mice boosted twice with △A146 Ply survived significantly longer than that for mice boosted once with △A146 Ply in Alum adjuvant,which were significantly longer than that of control group.Immunization with △A146 Ply was effective in reducing the numbers of pneumococcal strain 31614(serotype 14) and 31693(serotype 19F),which resulted in 50-and 20-fold decreases in bacterial load in the lungs respectively when compared to control protein-immunized mice.60% of vaccinated mice survived the infection with pneumococcal D39 of 1200 CFU.60% protection was achieved when mice intraperitoneally infected with D39 and received △A146 Ply-specific IgG,whereas no mice survived the infection when they were passively administered with △A146 Ply-specific IgG depleted antisera.Conclusion Immunization with △A146 Ply could confer protection against pneumococcal infections,and protection elicited was mediated by △A146 Ply-specific IgG.
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Objective:To construct the eukaryotic expression vector of open reading frame of KH gene(KH-ORF),an unknown gene obtained from K562 cells,and investigate its function.Methods:The KH-ORF cDNA was cleaved from plasmid expression vector cut with the same restriction endonucleases.pCI-KH-ORF,the pGEM-T-easy-KH-ORF with EcoRI and SalI and subcloned into the pCl-neo mammalian recombinant expression plasmid,was transfected into K562 cells with liposome and screened by G418.KH-ORF expression was tested by RT-PCR.The effect of expression product on cell proliferation was tested by growth-curve and LDH detection.Results:KH-ORF was expressed in K562 cells.The effects of increased proliferation were significant.Conclusion:The product of KH-ORF may be a functional protein that is related to the proliferation of K562 cells,and KH gene may be a functional unknown leukemia gene.
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Aim To investigate the effect of matrine on cytoskeletonof K562 cells. Methods Micropipette aspiration technique was adoptedto investigate the viscoelasticity of K562 cells, while the different ex-pression of cytoskeletal protein gene was analyzed by DNA microar-ray. Results In matrine-treated K562 cells, the viscoelastic propertiesKI, K2 and were decreased significantly from 726 ± 215 to 432 ±67,433 ±119 to 242±31, 72±38 to 50±15 respectively, and the geneexpression of prefoldin and ezrin was much stronger than that of controlcells. Conclusion The strueture and function can be changed in ma-trine-treated K562 cells.
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Objective:To construct the prokaryotic expression system of open reading frame of KH gene (KH-ORF),an unknown gene in K562 cells.Methods:The 225bp KH-ORF cDNA was cleaved from plasmid pGEM-T-easy-KH-ORF with EcoRI and SalI and subcloned into the pCI-neo Mammalian Expression Vector cutted with the same restriction endonucleases.The recombinant expression plasmid was transfected into BL21 (DE3) plysS by hot-shock assay.Induced by IPTG, the recombinant protein product was tested by SDS-PAGE.Results:24kD KH-ORF product was obtained as inclusion bodies in BL21 (DE3) plysS after the expression vector had been induced by IPTG for 30 minutes Conclusion :The construction of prokaryotic expression system of KH- ORF is successful.