Objective To establish the enzyme-linked immunosorbent assay (ELISA) methods for the quantitative determination of IgG antibodies against diphtheria (DT) and tetanus (TT).MethodsPurified diphtheria toxiod and tetanus toxoid were respectively used as the coating antigens,the human-derived serum antibody standard substance of DT and TT served as the standard substance.The dose-response curves of the tested samples and standard substance were fitted.Then the two quantitative ELISA methods for determining the antibody to DT (Anti-DT) and antibody to TT (Anti-TT) were established with the parallel lines method.Then the methodological verification and application study were conducted.Results The validation results of the two quantitative ELISA measurement methods were in accordance with the regulations.The quantity limit of ELISA method for quantitative detection of Anti-DT demonstrated to be 0.084 mIU/mL,its average recovery rate was 97.6%.The intra-assay coefficient of variation(CV) and inter-assay CV of this Anti-DT assay were ≤ 3.40% and ≤5.05%,respectively.The quantity limit of ELISA method for quantitative detection of Anti-TT demonstrated to be 0.175 mIU/mL,its average recovery rate was 97.5%.The intra-assay CV and inter-assay CV of this Anti-TT assay were ≤ 2.42% and ≤5.58%,respectively.These two methods were applied for the immunogenicity evaluation after infantile basic immunization by diphtheria and tetanus vaccines.Conclusion The two established quantitative ELISA methods demonstrate high accuracy and good reproducibility,which are suitable for the ordinary laboratory to carry out the work and can be used in the serological effect evaluation after diphtheria and tetanus vaccine immunization and epidemiological study of diphtheria and tetanus disease.

The authors have analyzed the present situation of teaching experiment in higher vocational education of china. And then the process of researching and practicing the basic medical experimental technique curriculum reform has been discussed from the aspects such as the teaching aims,curriculum setup,teaching content selection,teaching methods and education evaluation system for the purpose of exploring the experimental teaching mode to fulfill the requirements of the comprehensive career competence of higher vocational education.

Aim To establish an allogenetic mouse skin trans-plant model,in order to provide a research model for immunosup-pressive drugs. Methods Skins from the ears of C57BL/6 mice were transplanted to the back of BALB/c mice and skin isografts ( BALB/c mice to BALB/c mice) were used as control. Cyclos-porin A( CsA) was used as a model compound to test the imm-nosuppresive effect on allogenetic graft rejection. Following the transplation and CsA treatment, the graft rejection score and graft skin survival rate were quantified. Four and nine days after transplantation,serum IL-4,IL-12 and IFN-γ levels were meas-ured using ELISA kits. Twelve days after transplantation, mice were sacrificed. The weight of spleen and thymus was obtained, and CD4 + and CD8 + population of spleenic T cells were ana-lyzed using flow cytometer. Histological features were assessed by hematoxylin-eosin( HE) staining of formalin-fixed, paraffin-em-bedded graft skins. Results After transplantion, the graft rejec-tion score increased and graft skin survival rate decreased gradu-allly. Serum IL-12 and IFN-γ levels of allograft mice increased markedly. Compared with those of isograft mice, mice with skin allograft displayed a significant increase in the percentage of the CD8 + T cell subpopulation. Remarkable inflammation, such as edema, inflammatory cell infiltration were observed in allograft mice. Compared with saline treated mice, CsA significantly re-duced the graft rejection score and improved survival rate of skin grafts. And also, CsA treated mice had smaller spleen and thy-mus. Mice that received high doses of CsA had significantly less CD8 + T cells than those treated with saline. Moreover, allograft skins in mice that received CsA had less inflammation. Conclu-sions Allogenetic mouse skin transplantation exhibits acute graft rejection. CsA can inhibit the rejection in a dose dependent manner.

Based on recent studies which have shown that gut microbiota plays an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), the article elaborates on the relationship of NAFLD with intestinal endotoxemia, short-chain fatty acids, bile acid metabolism, and endogenous ethanol. By illustrating the author′s research progress in the relationship between traditional Chinese medicine (TCM) regulation of gut microbiota and NAFLD treatment, the article proposes that this approach is not only a clinical practice of TCM in the modern era, it may also become a new strategy in the treatment of NAFLD.

Objective:To investigate the molecular mechanism of autophagy and apoptosis induced by ultrafine carbon black in human bronchial epithelial cells (BEAS-2B cells), and to study the intervention effect and mechanism of N-acetylcysteine (NAC) on ultrafine carbon black-induced oxidative damage in BEAS-2B cells.Methods:In March 2023, BEAS-2B cells were used as research object, an in vitro airway model exposed to ultrafine carbon black was constructed. A control group and three carbon black exposure groups (50, 100, 200 μg/ml) were set up, and the cells were treated with corresponding concentrations of ultrafine carbon black for 24 hours. In addition, the experiment was divided into control group, NAC+ control group, 100 μg/ml carbon black exposure group and NAC+ exposure group. The corresponding groups were treated with 2 mmol/L NAC for 1 h and 100 μg/ml ultrafine carbon black for 24 h, respectively. Cell viability was measured by CCK-8 assay. Intracellular reactive oxygen species (ROS) level was detected by chemical fluorescence method. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), as well as the content of malondialdehyde (MDA) were detected by colorimetry. The mRNA and protein expressions of autophagy-related genes[Atg5, Atg7, Beclin1, microtubule-associated protein light chain 3B (LC3B), p62 and lysosome-associated membrane protein 2 (LAMP2) ] and apoptosis-related genes [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase3, Caspase9 and poly (ADP-ribose) polymerase 1 (PARP1) ] were determined by fluorescence quantitative PCR and Western blot. Cell apoptosis was determined by flow cytometry.Results:Compared with the control group, the relative survival rates of BEAS-2B cells in 50, 100, 200 μg/ml carbon black exposure groups were significantly decreased, the levels of ROS and MDA were significantly increased, and the activities of SOD, GSH-Px and CAT were significantly decreased ( P<0.05). The relative survival rate, ROS and MDA levels, SOD, GSH-Px and CAT activities were significantly correlated with the exposure dose of ultrafine carbon black ( rs=-0.755, 0.826, 0.934, -0.810, -0.880, -0.840, P<0.05). Compared with the control group, the relative expression levels of Atg5, Atg7, Beclin1, LC3B, p62, LAMP2, Bax, Caspase3, Caspase9, PARP1 mRNA and Atg5, Atg7, Beclin1, LC3BⅡ, p62, LAMP2, Bax, cleaved Caspase3 (C-Caspase3), cleaved Caspase9 (C-Caspase9), cleaved PARP1 (C-PARP1) protein and the ratio of LC3BⅡ/LC3BⅠ in 50, 100 and 200 μg/ml carbon black exposure groups were significantly increased, while the relative expression levels of Bcl-2 mRNA and protein were significantly decreased ( P<0.05). The changes of the above indexes were significantly correlated with the exposure dose of carbon black ( rs=0.892, 0.879, 0.944, 0.892, 0.828, 0.880, 0.814, 0.794, 0.931, 0.918, 0.813, 0.866, 0.774, 0.695, 0.918, 0.761, 0.794, 0.944, 0.833, 0.866, 0.905, -0.886, -0.748, P<0.05). Compared with 100 μg/ml carbon black exposure group, the relative survival rate, the activities of SOD, GSH-Px and CAT in NAC+exposure group were significantly increased, while the levels of ROS and MDA were significantly decreased, and the relative expression levels of LC3B, p62 and Caspase3 mRNA and protein as well as the ratio of LC3BⅡ/LC3BⅠ were significantly decreased, and the differences were statistically significant ( P<0.05). Compared with the control group, the apoptosis rates of BEAS-2B cells in 50, 100, 200 μg/ml carbon black exposure groups were significantly increased ( P<0.05), and there was a significant positive correlation between ultrafine carbon black exposure dose and cell apoptosis rate ( rs=0.944, P<0.05). While compared with 100 μg/ml carbon black exposure group, the apoptosis rate of NAC+exposure group was significantly decreased, and the difference was statistically significant ( P<0.05) . Conclusion:Cell autophagy and apoptosis may be important pathophysiological mechanisms of ultrafine carbon black-induced oxidative damage in BEAS-2B cells. NAC can alleviate the occurrence of BEAS-2B cell damage caused by ultrafine carbon black by regulating oxidative stress and the cascading autophagy and apoptosis pathways.

Objective:To investigate the molecular mechanism of autophagy and apoptosis induced by ultrafine carbon black in human bronchial epithelial cells (BEAS-2B cells), and to study the intervention effect and mechanism of N-acetylcysteine (NAC) on ultrafine carbon black-induced oxidative damage in BEAS-2B cells.Methods:In March 2023, BEAS-2B cells were used as research object, an in vitro airway model exposed to ultrafine carbon black was constructed. A control group and three carbon black exposure groups (50, 100, 200 μg/ml) were set up, and the cells were treated with corresponding concentrations of ultrafine carbon black for 24 hours. In addition, the experiment was divided into control group, NAC+ control group, 100 μg/ml carbon black exposure group and NAC+ exposure group. The corresponding groups were treated with 2 mmol/L NAC for 1 h and 100 μg/ml ultrafine carbon black for 24 h, respectively. Cell viability was measured by CCK-8 assay. Intracellular reactive oxygen species (ROS) level was detected by chemical fluorescence method. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), as well as the content of malondialdehyde (MDA) were detected by colorimetry. The mRNA and protein expressions of autophagy-related genes[Atg5, Atg7, Beclin1, microtubule-associated protein light chain 3B (LC3B), p62 and lysosome-associated membrane protein 2 (LAMP2) ] and apoptosis-related genes [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase3, Caspase9 and poly (ADP-ribose) polymerase 1 (PARP1) ] were determined by fluorescence quantitative PCR and Western blot. Cell apoptosis was determined by flow cytometry.Results:Compared with the control group, the relative survival rates of BEAS-2B cells in 50, 100, 200 μg/ml carbon black exposure groups were significantly decreased, the levels of ROS and MDA were significantly increased, and the activities of SOD, GSH-Px and CAT were significantly decreased ( P<0.05). The relative survival rate, ROS and MDA levels, SOD, GSH-Px and CAT activities were significantly correlated with the exposure dose of ultrafine carbon black ( rs=-0.755, 0.826, 0.934, -0.810, -0.880, -0.840, P<0.05). Compared with the control group, the relative expression levels of Atg5, Atg7, Beclin1, LC3B, p62, LAMP2, Bax, Caspase3, Caspase9, PARP1 mRNA and Atg5, Atg7, Beclin1, LC3BⅡ, p62, LAMP2, Bax, cleaved Caspase3 (C-Caspase3), cleaved Caspase9 (C-Caspase9), cleaved PARP1 (C-PARP1) protein and the ratio of LC3BⅡ/LC3BⅠ in 50, 100 and 200 μg/ml carbon black exposure groups were significantly increased, while the relative expression levels of Bcl-2 mRNA and protein were significantly decreased ( P<0.05). The changes of the above indexes were significantly correlated with the exposure dose of carbon black ( rs=0.892, 0.879, 0.944, 0.892, 0.828, 0.880, 0.814, 0.794, 0.931, 0.918, 0.813, 0.866, 0.774, 0.695, 0.918, 0.761, 0.794, 0.944, 0.833, 0.866, 0.905, -0.886, -0.748, P<0.05). Compared with 100 μg/ml carbon black exposure group, the relative survival rate, the activities of SOD, GSH-Px and CAT in NAC+exposure group were significantly increased, while the levels of ROS and MDA were significantly decreased, and the relative expression levels of LC3B, p62 and Caspase3 mRNA and protein as well as the ratio of LC3BⅡ/LC3BⅠ were significantly decreased, and the differences were statistically significant ( P<0.05). Compared with the control group, the apoptosis rates of BEAS-2B cells in 50, 100, 200 μg/ml carbon black exposure groups were significantly increased ( P<0.05), and there was a significant positive correlation between ultrafine carbon black exposure dose and cell apoptosis rate ( rs=0.944, P<0.05). While compared with 100 μg/ml carbon black exposure group, the apoptosis rate of NAC+exposure group was significantly decreased, and the difference was statistically significant ( P<0.05) . Conclusion:Cell autophagy and apoptosis may be important pathophysiological mechanisms of ultrafine carbon black-induced oxidative damage in BEAS-2B cells. NAC can alleviate the occurrence of BEAS-2B cell damage caused by ultrafine carbon black by regulating oxidative stress and the cascading autophagy and apoptosis pathways.