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AIM:To investigate the effect of doublecortin-like kinase 1(DCLK1)on the biological properties of gastric cancer stem cells,and to explore its possible mechanism.METHODS:Serum-free suspension culture of gastric cancer stem cells and targeted inhibition of DCLK1 activity in gastric cancer stem cells with DCLK1 inhibitor DCLK1-IN-1 were performed.The expression levels of DCLK1,stemness-related proteins(SOX2 and OCT4),proliferation-related pro-teins(cyclin D1 and c-MYC),drug resistance-related proteins(ABCG2 and TOP2A),epithelial-mesenchymal transition-related proteins(E-cadherin,vimentin and Snail),and PI3K/AKT/mTOR signaling pathway-related proteins in gastric cancer stem cells were examined by Western blot.The effects of DCLK1 on viability and drug resistance of gastric cancer stem cells were determined by CCK-8 assay,and the effects of DCLK1 on self-renewal of gastric cancer stem cells were de-termined by methylcellulose spheroid-forming assay.Wound-healing and Transwell assays were performed to assess the ef-fect of DCLK1 on the migration and invasion of gastric cancer stem cells.RESULTS:The expression levels of DCLK1 and stemness-related proteins SOX2 and OCT4 in gastric cancer stem cells were significantly higher than those in parental cells(P<0.01).The proliferation,drug resistance,migration and invasion of gastric cancer stem cells in DCLK1 inhibi-tion group were significantly lower than those in Sphere cell group(P<0.01).The expression levels of proliferation-related proteins(c-MYC and cyclin D1)and drug resistance-related proteins(TOP2A and ABCG2)were down-regulated,the ex-pression of epithelial marker E-cadherin was up-regulated,the expression of mesenchymal markers vimentin and Snail was down-regulated,and the expression levels of PI3K/AKT/mTOR signaling pathway-related proteins and their phosphoryla-tion levels were reduced in DCLK1 inhibition group(P<0.05).CONCLUSION:DCLK1 is highly expressed in gastric cancer stem cells,which may be involved in the proliferation,drug resistance and invasion of gastric cancer stem cells by regulating PI3K/AKT/mTOR signaling pathway.It suggests that DCLK1 can be used as a potential target for gastric cancer stem cells.
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Qinghai University lies in western China. There are some gaps between western and eastern universities at student level, education fund, experiment condition and technique supply for graduate students. To improve educational quality for graduate students, Department of Pathophysiology of Qinghai University focused on teaching methods, evaluation approaches and capacity of teachers and constructed a course named Clinical Pathophysiology for scientific research graduate students. The course adopted a series of measures such as combining lectures with students' self-learning (PBL, paper discussion, lecture for students), introducing experts from other schools to give lectures, establishing formative evaluation, optimizing teacher's group and so on, which have gained some achievements and improved the training quality for graduate students.
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In order to adapt to the demand of culturing high quality talents and to strengthen student's comprehensive quality,pathophysiology department of medical college of Qinghai University carried on the reform on the pathophysiological experiment examination system.After researches and practices in recent years,we established a set of relatively sound examination system including experiment operating and experiment report in normal study,report for designable experiment and experiment skill and theory exam.Investigation results demonstrated that examination system after reform functioned well in training the students' operation ability,observation ability and ability to analyze and solve questions.
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The levels of selenium in hair were determined by hydride generation atomic absorption spectropho-tometryin this assay. The working conditions of the determination were controlled as follows,wavelength: 196.00 nm,working current of lamp:6 mA,wide of filtered spectrum:4.0 A, flow rate of gaseous argon: 120 ml/min. The averagecontents of selenium in hair samples reached 0. 0498±0. 031 mg/kg. The detection limit and coefficient of variation were0. 5 ng/ml and 5.8% respectively. The recovery rates were 92.0%~ 104. 0% with an average of 99. 5%. This methodshowed advantages ,such as simple operation,rapid,low cost and high accuracy. The obtained data were reliable.
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AIM: To observe the effect of MM-LDL (minimally modified LDL) on the interaction between human umbilical vein endothelial cell (HUVEC) and U937 monocyte-like cell line and the exporession of vascular cell adhesion-1 (VCAM-1), intercellular adhesion molecule-1(ICAM-1), P-selectin.METHODS:The adhesive percentage between HUVEC treated with MM-LDL and U937 was determined by counting and the expression of VCAM-1, ICAM-1, P-selectin were examined by ELISA. RESULTS: Treatment of HUVEC with MM-LDL (75 mg/L) for 4 hours significantly increased adhesion of U937 to HUVEC ( P
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AIM:To provide evidence for the molecular mechanism of homocysteine (Hcy) as an independent risk factor in atherosclerosis (AS) by investigating the effect of Hcy on phenotype transformation and proliferation of vascular smooth muscle cells(VSMCs) in rats.METHODS:After treated with different concentrations of Hcy for 24 h,the cultured VSMCs were assayed for cell proliferation rate by MTT method,cell cycle by flow cytometry,the expression of SM22-? mRNA by semi-quantitative RT-PCR and the observation of morphological characteristics and the phenotype transformation by transmission electron microscopy.RESULTS:Hcy increased the cell proliferation rate and gradually reduced the proportion of the cells in G0 /G1 phase.Hcy down-regulated the expression of SM22? mRNA and the most significant effect was observed at concentration of 1 000 ?mol/L.The observations of transmission electron microscopy revealed an abundant endoplasmic reticulum,Golgi's complex,loose nucleus and puffy chromatin in VSMCs treated with high concentration of Hcy.CONCLUSION:Hcy promotes the proliferation and phenotype transformation of VSMCs simultaneously.
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AIM:[WTBZtive of this study was to examine the influence of different flow pattern, particularly low shear stress flow regimens, on VCAM-1 and NF-?B in vascular endothelial cells. [WTHZ] METHODS: HUVEC covered sheets were placed within rectangular parallel plate flow chambers. Cells were subjected to 4, 18 h of either laminar or oscillatory shear stress. The expression of VCAM-1 and NF-?B activity were analyzed by immunohistochemistry. VCAM-1 mRNA was also detected using in situ hybridization. RESULTS: VCAM-1 mRNA and VCAM-1 expression were not upregulated by laminar shear stress. However, oscillatory shear stress significantly upregulated VCAM-1 mRNA and VCAM-1 expression. Translocation of NF-?B P65 was remarkably increased. CONCLUSION: In same low shear stress, the different expression of VCAM-1 mRNA and VCAM-1 were induced by HUVEC exposed to laminar or oscillatory flow patterns.