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BACKGROUND:The physical properties and chemical composition of teeth are very similar with human bone tissue, and there are a larger proportion of inorganic components. Therefore, tooth can be considered as a potential repair material for autologous or alogeneic bone defects. OBJECTIVE:To prepare polyetheretherketone/odontogenic biphasic bioceramic composite, and to test its mechanical properties. METHODS: The humanin vitro teeth of clinical waste were colected. The organic components were removed after a preliminary calcination. Another calcination was conducted after soaking in diammonium phosphate solution for 24 hours to prepare the biphasic ceramics with the main components of hydroxyapatite and β-tricalcium phosphate. The biphasic ceramics were ground and sieved using 200-mesh sieve folowed by impregnation in organic foam to prepare polyetheretherketone/odontogenic biphasic bioceramics. Phase analysis, scanning electron microscopy, elemental analysis, porosity, compressive strength and bond strength test were conducted. RESULTS AND CONCLUSION:Polyetheretherketone/odontogenic biphasic bioceramics presented porous network structure and interconnected holes, with the aperture of 100-800 μm, porosity of 73.65%, compressive strength of (165.260±11.703) N, bond strength of (14.63±6.21) MPa. P element content accounted for 19.8%, and Ca element content accounted for 40.5%. The main phases were β- tricalcium phosphate and hydroxyapatite. These results demonstrate that polyetheretherketone/odontogenic biphasic bioceramics have good mechanical properties.
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Objective: To establish a cell culture model of cervical-loop epithelial cells from Wistar rat lower incisors on culture bottle coated with rat tail collagen. Methods: The effect of self-made rat tail collagen on the culture of cervical-loop epithelial cells was observed. The cells were identified by immunohistochemistry staining. Results: Cervical-loop epithelial cells in Wistar rat lower incisors grew well in self-made rat tail collagen. The cervical-loop epithelial cells exhibited positive expression for integrin-β1 and monoclonal antibody CK in immunohistochemistry staining. Conclusion: The cell culture model of cervical-loop epithelial cells in Wistar rat lower incisors with self-made rat tail collagen can be helpful to research tooth development mechanism.
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Objective To study the effect of thermo-radiotherapy on multidrug resistance (MDR) and levels of intracellular adriamycin (ADM) in tongue squamous cell carcinoma cell line Tca 8113 and its MDR cell line Tca 8113/CBDEA. Methods Samples of the two cell lines were treated with thermo-radiotherapy (42℃ for 0.5 h and 2 Gy of radiation). Four and 24 hours later, the expression of the MDR relative proteins P-glycoprotein (P-gp),multidrug resistance associate protein 1 (MRP1) and glutathione s-tranferase-π (GST-π) were detected using immu-nohistochemistry. Intracellular ADM concentrations were measured using an HTS 7000 Plus bioassay reader. Re-sults No change in the expression of P-gp was observed in the Tca 8113/CBDEA and Tca 8113 cell lines after 4 or 24 hours. Expression of MRP1 was not significantly altered in the Tca 8113/CBDEA cell line, but there was a signifi-cant drop in the Tca 8113 cell line 24 hours post-thermo-radiotherapy. Expression of GST-π was not altered in either the Tca 8113/CBDEA or the Tca 8113 cell line at 4 hours post-thermo-radiotherapy, but there was a significant de-crease at 24 hours. At both 4 and 24 hours, drug tolerance had decreased and intracellular drug concentration had in-creased significantly in both cell lines. Conclusions Thermo-radiotherapy can enhance the effects of chemotherapy and suppress the expression of MDR factors induced by radiation. The combination of hyperthermia and radiotherapy does not induce MDR.
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<p><b>OBJECTIVE</b>To study the drug resistance changes in Tca8113 cell lines by exposing to carboplatin.</p><p><b>METHODS</b>The concentration of carboplatin added to Tca8113 cells was increased gradually and continually, which was to induce the carhoplatin-resistance in Tca8113 cells. The sensibility to drugs of the cells was analyzed by MTT method. Immunocytochemistry and RT-PCR were utilized to examine the expression of multidrug resistance proteins and genes.</p><p><b>RESULTS</b>After exposing to carboplatin, the Tca8113/CBP cells had higher drug-resistance to CBP, MTX, PYM, VCR and higher expression of MRP, GST-pi than Tca8113 cells.</p><p><b>CONCLUSION</b>Multidrug resistance of Tca8113/CBP is associated with over expression of MRP, GST-pi and MDR. Tca8113/CBP can provide an ideal model for multidrug resistance research.</p>
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Humanos , Antineoplásicos , Linhagem Celular , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos AntineoplásicosRESUMO
Objective:To study the differences of gene expression between Tca8113 and Tca8113/CBP tissues in nude mice. Methods:Tca8113 cells were injected subcutaneously in both sides of armpits of nude mice at the concentration of 5?106 cells/0.1 ml. Two weeks after injection, Carboplatin was used subcutaneously around the tumor 0.01 mg/g (weight) each day in Tca8113/CBP group while Tca8113 group was injected with physiologic saline as control. Mice were sacrificed 10 weeks after drug injection. The two kinds of tissues were investigated by human 16k cDNA v2.1 SBC-R-HC-100-21 gene chip. Results:Among the 16 000 target genes, there were 719 genes whose expression levels showed differences between the two kinds of tumor tissues. Conclusion:Microarray technique can simultaneously screen different genes from above-mentioned two kinds of tissues. Further analysis of the obtained genes will be helpful to understand the molecular mechanism of multidrug resistance.
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Objective:To study radiation sensibility of tongue squamous cell carcinoma cell line Tca 8113 and its multidrug resistance(MDR)cell line Tca 8113/CBDEA.Methers:MTT assay was used to determine the sensitivity of the cells to radiation.Cells were treated with 2 Gy of ?-radiation for 4 or 24 h.Real-time quantitative reverse transcriptase-polymerase chain reaction(RT-PCR)was used to detecte the expressions of mdr related genes(mdr1,mrp1,gst-?)and HTS 7000 Plus Bio Assay Reader was used to measure intracellular ADM concentration.Results:Tca 8113/CBDEA cells were 1.24-fold more radiation resistant than that of Tca 8113 cells(P0.05),while increased 24 h after radiation(P
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Objective: To observe the expression of urokinase-type plasminogen activator receptor (uPAR) in human tongue squamous cell carcinoma Tca 8113 cells at different dosages of heat shock. Methods:The expression of uPAR protein in Tca 8113 cells was examined using immunohistochemical technique (IH) and flow cytometry (FCM) after the cells had been treated at 37,40,43 or 45 ℃ for 40 min. Results:The fluorescent intensity of uPAR protein of Tca 8113 cells treated at 37,40,43 and 45 ℃ was 11.36?0.06,9.98?0.12, 10.37?0.05 and 11.31?0.10 respectively.Conclusion:Heat shock can reduce the expression of the uPAR protein of Tca 8113 cells.