Objective To investigate the toxicity of urban PM2.5 in Guangzhou on PC-12 cells.Methods PM2.5 was collected in Guangzhou city.PC-12 cells were cultured in vitro and divided into several groups,including the control group,PM2.5 groups with different concentrations and NAC pretreated group (pretreaed with 10 μmol/mL NAC followed with 100 μg/mL PM2.5 exposure).Cells were incubated with indicated stimulator for 24 h,then cell viability was checked with cell counting Kit-8 assay,the level of intracellular ROS was labeled using H2DCFDA fluorescence probe,cell apoptosis was measured by the flow cytometry and the expression of apoptosis-related proteins,including Cytochrome C,Caspase 9,Caspase 3 and PARP,were detected by Western Blot assay.Results PM2.5 has a strong toxicity on PC-12 cells when its concentration is over 25 μg/mL.After exposure for 24 h,the cell viability was markedly decreased.The results of flow cytometry and Western blot assay showed that PM2.5 enhanced the apoptosis of PC-12 cells with the upregulatios of Cytochrome C,Caspase 9,Caspase 3 and PARP.Pretreatment with NAC could significantly diminish PM2.5-induced PC-12 cell toxicity,decreased ROS generation and apoptosis of PC-12 cells,with the down regulations of apoptosis-related proteins.Conclusion PM2.5 can cause apoptosis of PC-12 cells by inducing oxidative stress,upregulating the Cytochrome C expression and activating Caspase9/3,which may be one of the mechanisms underlying PM2.5-induced neurotoxicity.

AIM:To study the toxicity of PM2.5 in the endothelial cells by investigating the induction of reactive oxygen species (ROS) and apoptosis in EA.hy926 cells exposed to PM2.5.METHODS: The endothelial cell line EA. hy926 was cultured in vitro and exposed to PM2.5 at different concentrations for 24 h.The cell viability was measured by CCK-8 assay and the generation of intracellular ROS was stained with DCFH-DA.The cell apoptosis was analyzed by flow cy-tometry with Annexin V-FITC/PI staining, and the protein levels of cytochrome C , caspase 9 and caspase 3 was detected by Western blot.RESULTS:After the treatment with PM2.5, the viability of the EA.hy926 cells was decreased markedly and the production of ROS was increased significantly .PM2.5 exposure upregulated the expression of cytoplasm cytochrome C and activated caspase-9 and caspase-3, resulting in the increase of the cell apoptosis significantly .The ROS generation was direct-ly involved in PM2.5-mediated endothelial cell apoptosis as N-acetyl-L-cysteine pretreatment abolished both ROS production and cell apoptosis induced by PM 2.5.CONCLUSION:PM2.5 induces oxidative stress and apoptosis in the vascular endo-thelial cells, which may be one of the mechanisms that PM2.5 influences the function of cardiovascular system .

"Fostering virtue through education"is the fundamental task of higher medical education.Specialized curriculum is the basic carrier of ideological and political education construction.Microbiology and Immunology is a basic course of medicine,which is closely related to people's health,clinical diagnosis and treatment.Based on the professional knowledge system of the curriculum,teaching team carried out the exploration of ideological and political education in both theoretical and experimental teaching.In order to train socialist medical qualified personnel with both virtue and ability,we integrated ideological and political education into all aspects of teaching and the whole process,such as teachers'teaching ability,curriculum teaching objectives,teaching content,teaching methods,etc.

Objective To measure and investigate the anatomical characteristics of the proximal femur canal curves in patients with developmental dysplasia of the hip (DDH), and to provide references for the design of femoral stem of DDH patients. Methods Three-dimensional reconstructions of the proximal femur were conducted from the CT data, and the anatomical morphology characteristics were obtained from 64 patients with DDH (74 hips, 12 males, 52 females, average age of 45.3 years) and 30 healthy controls (30 hips, 21 males, 9 females, average age of 29.4 years). Multiple anteroposterior diameter and mediolateral diameter around the lesser trochanter at different heights and the fitting curves of different groups were obtained. Results The femoral neck anteversion angle, neck-shaft angle, height of the isthmus, canal flare index (CFI), femoral head diameter and femoral offset of DDH patients and healthy controls were 26.39°±14.74° and 15.68°±7.95°, 125.65°±5.73° and 129.19°±5.80°, (99.14±14.62) mm and (110.13±11.73) mm, 3.63±0.77 and 4.45±0.79, (44.01±5.75) mm and (47.26±3.94) mm, (31.80±3.82) mm and (36.42±4.84) mm, respectively. DDH group had the significantly greater femoral neck anteversion angle, and other anatomical morphology characteristics were significantly smaller than the control group. The obtained anteroposterior diameter, mediolateral diameter and the fitting curves showed that DDH group had narrow medullary cavity and forward shifting anteroposterior diameter. In addition, there was a statistical significance between the Crowe Ⅳ DDH and other types of DDH, and deformation degree of the femur increased with the increase of DDH type. Conclusions The proximal femur of DDH patients was significantly different from the healthy controls. Moreover, there were significantly morphological differences between different types of DDH. The research findings can be used as quantitative references for understanding the morphological feature of DDH patients and the corresponding design of femoral stem for DDH patients.

Objective Aiming at solving the problems of pain on the anteromedial tibia, tibial component loosening and osteoarthritis progression after unicompartmental knee arthroplasty (UKA), the influence of different geometric shapes of tibial component pegs on stress distributions in tibia was analyzed by finite element method. Methods The finite element models with UKA were established and validated. Geometric shapes of tibial component were designed. Under the same loading condition, the tibial components with double-peg, single-keel, double-keel and cross-star were studied for finite element analysis and compared with intact model, so as to evaluate the influence of tibial component with different shapes on stresses of cortical bone in anteromedial tibia, cancellous bone under tibial component and cartilage in contralateral tibia. Results Compared with the intact model, the peak stress of cortical bone in anteromedial tibia with double-peg, single-keel, double-keel and cross-star tibial components increased by 56.1%, 55.9%, 54.5% and 68-4%, respectively. The peak stress of cancellous bone under tibial component with single-keel and double-keels decreased by 8.1% and 15.6% respectively, while the peak stress of cancellous bone under tibial component with double-peg and cross-star increased by 67-9% and 121-5%, which were higher than the fatigue yield stress of cancellous bone. The peak stress of cartilage in contralateral tibia with double-peg, single-keel, double-keel and cross-star tibial components decreased by 42.1%, 26.6%, 24.2% and 28.5%, respectively. ConclusionsThe load distribution of the medial and lateral tibia changed after UKA operation, and a greater load was observed on the replacement side. Single-keel and double-keel tibial components were more effective in reducing stresses on cortical bone in anteromedial tibia and cancellous bone, while the stress distribution in tibia with single-keel tibial component was closer to that of the intact tibia. The research findings can provide theoretical references for designing single-keel tibial component of unicompartmental knee prosthesis which conforms to better mechanical properties of the knee joint.