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Objective To improve the classroom environment and students' learning effect and in-novation of classroom teaching mode. Method We took stomatology students of Grade 2012 (control group, 60 people) and Grade 2013 (experimental group, 69 people) as research subjects, and in the control group, the traditional teaching method was used, while the experimental group was based on the mixed mode of the flipped classroom. By comparison of the result of questionnaire survey and final examination between the experimental group and control group, we made clear the difference between blended classroom teaching and traditional classroom teaching. SPSS 16.0 was used for statistical analysis and the data was made t test and rank sum test, and the result was showed by rate and (x±s). Result The classroom performance of the control group was (14.78±4.27), and the experimental result was (14.49±4.49), in the experimental group, the internal and external performance of the experimental group was (22.19±7.21), the experimental result was (7.12±1.33). By comparison of the result of examination between the experimental group (49.01±7.28) and control group (46.32 ±7.44), medical immunology test scores were significantly different (P<0.05), and the experimental group was better than the control group. It showed that the mixed teaching model had more advantages in improving the academic performance. The results of questionnaire survey showed that flipped classroom teaching was better than traditional classroom teaching in ability training which included self learning ability (68.18%, 45 people), analysis and problem solving skills (68.18%, 45 people), team work and communication skills (56.06%, 37 people), ability of retain knowledge (46.97%, 31 people), however students who liked and accepted this new teaching model only accounted for about 30.00%. Conclusion Inte-gration of flipped classroom mode with traditional mode will enhance the students' learning efficiency and achievements, as well as promote students' ability.
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BACKGROUND: Mitochondria are not only the important place for consuming oxygen and producing free radical, but also an aggressive target place by endogenous free radical. The changes of structure and function of mitochondria will be take place with aging. Portulaca (Portulaca oleracea L.) is usually called as the macrobiotic vegetable. Portulaca is eutrophic and anti-free radical. It is worth exploring whether the anti-aging action of Portulaca is correlated with its protection on myocardial mitochondria.OBJECTIVE: To observe the effects of the Portulaca water extract on the lipid peroxidation myocardial mitochondrial phospholipid and the activity of respiratory chain enzymes in aging model mice, and analyze the pathway of protective effect on myocardial mitochondria.DESIGN: A completely randomized design and controlled animal experiments.SETTING: Department of Biochemistry, School of Basic Medical Sciences, Jiamusi University.MATERIALS: ①The animals were raised and the experiments were completed in the Experimental Animal Center of Jiamusi University from March 2003 to August 2004. The animals were killed, hearts were removed and mitochondria were harvested in the Department of Biochemistry; The indexes were determined in the Department of Biochemistry,experimental center and the College of Chemistry and Pharmacology. ② Thirty healthy adult Kunming mice (either male or female) were divided into 3 groups by random feeling ball method: young control group (n =8), aging model group (n =11) and Portulaca treated group (n =11). ③ Portulaca was offered by Jiamusi Institute of Chinese Herbs, and appraisement by the Department of Crude Drug of Jiamusi University. Portulacas were made into water extract (crud drug 1 kg/L). Standard cardiolipin was offered by Sigma Company (USA), kits for malonaldehyde (MDA) and the activity of Ca2+-adenosine triphosphatase (Ca2+-ATPase) were provided by Nanjing Jiancheng Bioengineering Institute.METHODS: ①The aging model mice were daily given subcutaneous injection of D-galactose on the nape back (100 mg/kg);Besides, mice in the Portulaca treated group were perfused with the Portulaca water extract (13 g/kg per day) for 30 days continuously, and those in the young control group were daily given subcutaneous injection of saline of the same volume for 30 days continuously. All the mice were killed on the next day after the last administration, and then hearts were quickly removed and reserved. ② Mitochondria were prepared according to the method provided by Nanjing Jiancheng Bioengineering Institute. The MDA content and the activities of Ca2+-ATPase were determined following the illustration of the kit. The relative amount of cardiolipin in phospholipid on the mitochondrial membrane was determined with the high-performance liquid chromatography. The activities of Complex Ⅰ and Complex Ⅱ +Ⅲ were measured by Wu's method. ③ The differences of measurement data were compared with the analysis of variance and t test.MAIN OUTCOME MEASURES: ① Composition of phospholipid on myocardial mitochondrial membrane of mice; MDA content, activities of Complex Ⅰ, Complex Ⅱ +Ⅲ and Ca2+-ATPase in mitochondria.RESULTS: All the 30 mice were involved in the final analysis of results. ① MDA contents in myocardial mitochondria: It was significantly higher in the aging model group [(8.827±0.873) μ mol/g] than in the young control group and Portulaca treated group [(5.194±0.674), (5.901±0.743) μmol/g, t =7.48, 7.22, P ＜ 0.01]. ② Relative amounts of cardiolipin and the activities of Ca2+-ATPase in myocardial mitochondria: Those were obviously lower in the aging model group [cardiolipin:(0.156±0.012) mg/g, (1.267±0.167) μkat/g] than in the young control group and Portulaca treated group [(0.190±0.022),(0.184±0.021) mg/g; Ca2+-ATPase: (1.870±0.254), (1.780±0.237) μ kat/g, t =3.23,5.61, P ＜ 0.05-0.01]. ③ Activities of Complex Ⅰ and Complex Ⅱ + Ⅲ in myocardial mitochondria: Those were significantly lower in the aging model group [(3.517±0.383), (20.217±2.200) μkat/g] than in the young control group and Protulaca treated group [Complex Ⅰ:(6.817±0.600), (6.067±0.750) μ kat/g; Complex Ⅱ + Ⅲ: (56.400±4.933), (51.800±4.217) μkat/g, t =5.74,9.86, P ＜ 0.01].CONCLUSION: The Portulaca water extract has the protective effect on myocardial mitochondria by inhibiting the lipid peroxidation in myocardial mitochondria and enhancing the activities of respiratory chain enzymes.
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BACKGROUND: The death of aging cells is virtually apoptosis. To a certain extent, it can be interpreted as a series of results of gere activities.Therefore, the inhibition of oncogene's expression can lengthen the life span of cells and delay aging of brain tissues.OBJECTIVE: To study the effect of abstragulus mongholicus bung (AMB) on apoptosis of nerve cells and the expression of relevant gene in aging mice brain.DESIGN: Completely randomized design and controlled experiment.SETTING: Department of Biochemistry, School of Basic Medical Sciences of Jiamusi University.MATERIALS: The experiment was conducted at the Experimental Animal Center and Biochemical Laboratory of Jiamusi University from December 2003 to May 2004. Totally 24 healthy Kunming mice were recruited in this study. There were 8 two-month-old mice (young group) and 16 twelve-month-old mice. All the 16 mice were randomized into abstragulus mongholicus bung group and old control group with 8 in each group.METHODS:① AMB group:Mice in AMB group received gastric gavage was provided by the Department of Traditional Chinese Medicine of the First Hospital Affiliated to Jiamusi University, and evaluated by Jiamusi Drug Inspection Bureau. Water decoction was prepared with 2 kg/L raw materials. Mice in old control group and young group were filled with lukewarm boiled water.② All the animals were treated as above for 30 consecutive days before put to death. Their brains were taken out immediately and the middle parts of the brains were removed to fix with neutral formaldehyde. The remaining brain tissues were made into mitochondria suspension. Content of manganese superoxide dismutase (Mn-SOD) and malondialdehyde (MDA) was determined with xanthosine oxidase method and TBA chemical colorimetry. Apoptotic cells (cells with yellow nuclei were positive ones) were assayed with in situ end-labeling (ISEL) and expression of bcl-2 gene was assayed with immunohistochemical method. The cells stained brown were positive ones. A total of 400 cells were counted under the 400× microscope. We graded the samples according to the percentage of the positive cells: the number of positive cells ＜ 5% -; 5%-10％ +; 11％-50％ ++; ＞ 51％ ().③ Grade and quantitative data were compared with rank sum test and t-test.MAIN OUTCOME MEASURES: Effects of AMB on the rate of neu-ronal apoptosis, the activity of Mn-SOD, the concentration of MDA in mitochondria, and the intensity of the expression of bcl-2 gene.RESULTS: Totally 24 mice entered the final analysis.① Content of MnSOD was higher in young group and AMB group than in old control group (P＜0.05).② Concentration of MDA and apoptotic rate in young group and AMB group were lower than those in old control group (P ＜ 0.01).③Expression of bcl-2 gene was significantly different in young group and AMB group from that in old control group (P ＜ 0.01).CONCLUSION: AMB is found to be able to obviously inhibit neuronal apoptosis in aging mice brain by affecting the activity of Mn-SOD, the concentration of MDA and the expression of bcl-2.
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AIM:To study the mechanism of oleanolic acid induced apoptosis and its influence on cell cycle in HL-60 cells in vitro.METHODS:The HL-60 cells were treated with different concentrations of oleanolic acid and then cultured for 12 h,24 h,48 h and 72 h,respectively.MTT assay was used to evaluate the inhibitory effect of oleanolic acid on HL-60 cells in vitro.The argarose gel electrophoresis was used to detect the chromatin DNA fragmentation.FACS was used to analyze the cell cycle of HL-60 cells.Western blotting was used to detect the activation of caspase-3 which has been confirmed the last execution of apoptosis pathway.RESULTS:MTT assay showed that oleanolic acid dramatically inhibited the growth of HL-60 cells in vitro,more than 50% HL-60 cells were inhibited when the cells were treated with 80 ?mol/L oleanolic acid for 48 h;the apparent DNA ladder was detected after exposure of HL-60 cells to oleanolic acid for 48 h.FACS analysis showed that cell cycle of HL-60 cells was arrested in G1 phase,the inhibition ratio of HL-60 cells achieved 63.24% and 67.90% after treated with oleanolic acid for 48 h and 72 h correspondingly.Western blotting detected the activation of caspase-3 after exposure of HL-60 cells to 80 ?mol/L oleanolic acid for 48 h.CONCLUSION:These results suggest that oleanolic acid induces apoptosis and the cell cycle of HL-60 cells is arrested in G1 phase.