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This paper elaborates the specific implementation process of the "research-based learning" teaching reform of genetic experiment in medical undergraduate education, including the change of teaching philosophy among teachers, the integration and expansion of experimental contents, the innovation of classroom-teaching model, the compilation of proper textbook, the update of assessment methods and the establishment of evaluation mechanism for teaching and so on. Preliminary research shows that RBL teaching reform can stimulate medical students' interest and potential in learning, and improve their practical and scientific research innovation ability.
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Objective To analyse the change of DNA methylation with 5-Azac injection in acute graft-versus-host dis- ease (aGVHD) mouse model, which received allogeneic bone marrow transplantation, and explore the immunomodulatory ef-fects of 5-Azac. Methods Male C57BL/6 (H-2b)and female BALB/c (H-2d) mice were selected as donor and recipient of complete allotransplantation. BABL/c mice were divided into two groups, transplantation control group and 5-Azac experi-mental group. At 1-7, 14, 21 and 28-day after transplantion, 5-Azac 0.25 mg/kg (0.3 mL/time) was injected by tail vein in experimental group, while the control group were injected with sterile water 0.3 mL/time. Peripheral blood DNA samples were collected from three control mice and three experimental mice, then mixed with equal amount respectively. The MeDIP-seq method was selected to detect methylation changes in mice, and the differential DNA methylation in the biological path-ways was analyzed. Results The survival time was prolonged, and the rejection reaction was decreased in 5-Azac experi-mental group, which suggested immune hyporesponsiveness post aGVHD. The MeDIP-seq result showed that 369 different DNA methylation located in the promoter regions, including 239 up-regulated genes and 130 down-regulated genes. There were 184 differential DNA methylation genes located in the exon regions, including 113 up-regulated genes and 71 down-regulated genes. Differential DNA methylation genes involved in 10 immunological signaling pathways, respectively. Among them, TGF-β, GSK-3β, SYK, PI3K, NFAT, CD28 andα4β7 were closely related to the development of aGVHD. Conclu-sion 5-Azac can effectively induce immune hyporesponsiveness post aGVHD by changing the gene methylation status.
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Objective:To assess the expression levels of CD95 and OX40 ligand(OX40L)messenger RNA(mRNA)in hepatocellular carcinoma(HCC),and their clinical values thereof.Methods:The lymphocytes of research objects were mixed with corresponding fluorescence labeled monoclonal antibody(McAb);CD95 expression by CD3 positive T ceils was quantitatively measured by dual color flow cytometry.The expression of OX40L mRNA was detected in peripheral blood mononuclear cells by fluorescence quantitative reverse transcription polymerase chain reaction(FQ-RT-PCR).Results:The CD95 expression by CD3 positive T cells was significantly higher in patients with HCC(34±20)% compared with that of normal controls (20±7)%(t=2.960,P ＜ 0.01).The expression level of OX40L mRNA was significantly decreased in patients with HCC compared with that of normal controls(t=2.302,P ＜ 0.05).Conclusion:These results suggest that abnormal expressions of CD95 and OX40L play crucial roles in peripheral blood of HCC patients at the stage of human hepatocareinogenesis.
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Objective To evaluate the effect of different densities of830nm laser irradiation on genetic damages in mice cells.Methods 100Kunming mice were randomly divided into micronuleus groups and sperm group,as well as control group.Mice thymus glands and spleens were irradiated with an830nm semiconductor laser,30mW for5minutes or20minutes each day in vitro,and the micronuclei of polychromatic erythrocytes in sternum bone marrow and rate of abnormal sperm produced were determined.Results Laser irradiation induced deformed sperm(? 2 =111.747,P=0.000),while higher dose(20min per day)laser irradiation increased the micronuclei of polychromatic erythrocytes in sternum bone marrow.There was statistical significance in the difference between the rates of abnormal sperm and micronuclei in sternum bone marrow caused by irradiation on thymus and spleen(? 2 =27.395,P=0.000)and there was dosage effect.The spleen was the more sensitive.Conclusion Laser irradiation at830nm might have a genetic damages to mice cells.Attention should be paid to the potential hazardous effects induced by semiconductor laser irradiation.
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Objective To explore the genetic damages of people exposed to electronic waste from three villages that have been processing the electronic waste collectively in county of Tianjin, and to analyze the damaging effects of the electronic pollutants on the genetic substances. Methods The blood samples of 1 256 villagers from this region were collected to do chromosomal karyotype analysis, from which 171 samples were randomly chosen to do micronucleus test, 12 samples were chosen to do comet assay experiments. 60 villagers living far from the electronic waste processing regions were chosen as the control group. Chi-Square test and T-test were employed to do statistic analysis. Results The chromosomal structural aberration in the research group was 6.23%, and the number aberration was 0.29%. Both of chromosomal conjoint and satellite conjoint were higher compared with the control (P