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The COVID-19 pandemic caused by the novel SARS-CoV-2 virus has caused havoc across the entire world. Even though several COVID-19 vaccines are currently in distribution worldwide, with others in the pipeline, treatment modalities lag behind. Accordingly, researchers have been working hard to understand the nature of the virus, its mutant strains, and the pathogenesis of the disease in order to uncover possible drug targets and effective therapeutic agents. As the research continues, we now know the genome structure, epidemiological and clinical features, and pathogenic mechanism of SARS-CoV-2. Here, we summarized the potential therapeutic targets involved in the life cycle of the virus. On the basis of these targets, small-molecule prophylactic and therapeutic agents have been or are being developed for prevention and treatment of SARS-CoV-2 infection.
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Objective:To study the biological safety and biocompatibility of the mixture of Paris polyphylla-chitosan.Methods:According to the GB/T 16886.12-2005 standard,YY/T 0279-1995 standard and GBT16886.5-2003 standard,samples were prepared and tested by oral mucous membrane irritation test,cytotoxicity test and flow cytometry.Results:No local response to the mixture of Paris polyphylla-chitosan was found,and the visual observation and pathological findings of oral mucosa were normal and similar to that of the control group.Therefore,the mixture of Paris polyphylla-chitosan had no irritation response to oral mucosa.The mixture of Paris polyphylla-chitosan showed no cytotoxicity to L929 cells,and did not affect the cycle distribution and apoptosis of L929 cells.Conclusion:The mixture of Paris polyphylla-chitosan has good bio-safety and biocompatibility.
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Objective:To compare the wear resistance between dentin and dental restoration material in vitro.Methods:The friction and wear behaviors of natural tooth dentin respectively against highly polished polymer ceramic,glass ceramic and zirconia were investigated in an artificial saliva test environment by UMT-2 friction and wear testing machine.Worn surface morphology was observed by scanning electron microscopy(SEM),roughness was measured by roughness instrument,the rigidity value was weighed by electronic balance.Results:The roughness of the 3 materials was similar to that of dentin(P ＞ 0.05),the rigidity of dentin was less than that of the 3 materials (P ＜ 0.05).After friction and wear test,the abrasion quantity of dentin respectively against the 3 materials was less than that of the materials (P ＜ 0.05).There was positive correlation between the wear loss and the hardness of the 3 materials and dentin(r =0.846).The mass loss of the dentin against Poly Ceramic after grinding abrasion was the closest among the 3 materials.Conclusion:Different materials have varying degrees abrasion against dentine.The Polymer Ceramic has closer abrasion performancez with dentin than the other 2 materials.
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Objective@#To investigate the effect of triptolide on human oral cancer cell (HB) proliferation and phosphates and tensin homologue deleted on chromosome ten gene (PTEN) mRNA expression in oral cancer.@*Methods@#The cancer cells were cultured in the medium containing triptolide of different concentrations for 24, 48 and 72 h. Methyl thiazolyl tetrazolium (MTT) method was used to test the rate of growth inhibition of cancer cells, flow cytometer to detect the change of cell cycle and reveres transcription-PCR (RT-PCR) to examine the expression of PTEN mRNA. The expression of PTEN protein was examined by Western blotting.@*Results@#The rate of growth inhibition was (26.92 ± 0.14)%, (38.67 ± 0.11)%, (72.62 ± 0.89)% and (90.42 ± 0.28)%, respectively. The corresponding expression of PTEN mRNA was (3.59±0.21)%, (5.27±0.40)%, (7.18±0.44)% and (9.16±0.50)%, respectively and the corresponding A value of PTEN protein was 0.135±0.007, 0.410±0.020, 0.447±0.017 and 0.884±0.066, respectively. The proportion of G1 phase cells increased from (58.78±0.98)% to (84.13±0.47)%, but the proportion of S phase cells decreased from (25.40±0.43)% to (9.41±0.73)%.@*Conclusions@#The triptolide not only had inhibitory effect on the HB proliferation, but also affected the cell cycle.
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<p><b>OBJECTIVE</b>To investigate the effect of different surface treatment of zirconia and to find the best way to reduce the wear of its antagonist.</p><p><b>METHODS</b>Twenty-five plates(5 mm×10 mm×15 mm) made of zirconia were divided into five equal groups. Group A was only ground, group B was ground and polished, group C was ground and polished then polished by prophylaxis paste, group D was ground and glazed, group E was ground, polishsed, and then reglazed. Five central incisors were embedded in autopolymerizing acrylic resin with a size of 5 mm×10 mm×15 mm as the control group F. Thirty upper premolars buccal cusps were prepared as the antagonist. Cusps were embedded in autopolymerizing acrylic resin with a shape of circular column whose diameter were 3.1 mm. The wear test was performed in the universal micro-tribotester in artificial saliva. The roughness of each group was measured with rough meter before the wear test. The volume loss of the antagonist was measured using a 3D scanner. The wear surface was observed with scanning electron microscopy to determine the wear characteristics. Data were analyzed using one-way analysis of variance.</p><p><b>RESULTS</b>Each group of surface roughness and mass loss of antagonist showed significant statistical difference (P<0.05). Antagonist of group D showed the maximum volume loss([0.905±0.018] mm3). Antagonist of control group showed the least volume loss([0.235±0.017] mm3). Antagonist of group C showed less volume loss than antagonist of control group did([0.413±0.017] mm3). Wear type of enamel of control group and the antagonist of the groups in which the samples were polished with prophylaxis paste was fatigue wear, and the other groups showed abrasive and adhesive wear.</p><p><b>CONCLUSIONS</b>In the surface treatment methods of zirconia, polishing is better than glazing. Ground and polishing and then polishing with prophylaxis paste can decrease the wear of the antagonist.</p>
Subject(s)
Humans , Bicuspid , Dental Enamel , Dental Polishing , Materials Testing , Microscopy, Electron, Scanning , Surface Properties , Tooth Crown , Tooth Wear , ZirconiumABSTRACT
Objective:To study the surface structure and antibacterial property of Ag-containing coating(AgCC)on casting cobalt chromium alloy(Co-Cr).Methods:Plasma spraying technique was adopted to prepare AgCC on Co-Cr.Scanning electron microsco-py,energy dispersive analysis and X-ray diffraction analysis were used to evaluate the surface properties.The antibacterial effects of AgCC against staphylococcus aureus and candida albicans were examined by film attachment method.Fluorescence microscope was a-dopted to evaluate the bacteria adhesion property.Results:AgCC surface was uniform and compact,combined perfectly with sub-strate material.The content of the surface was mainly Ag,Cr and a small amount of Ag2 O and Cr2 O3 .The results of antibacterial as-say showed that on AgCC the number of bacterial colony was fewer(P<0.05)and bacterial adhesion was less than those on Co-Cr(P<0.05).Conclusion:AgCC surface was stable and has antibacterial property.
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<p><b>OBJECTIVE</b>To investigate the effects of the leaching liquids of 4 differents kinds of dental alloys (Au alloy, Ag-Pd alloy, Co-Cr alloy, Ni-Cr alloy) on apoptosis related gene and protein of fibroblast L929.</p><p><b>METHODS</b>The L929 cells of mouse were treated in vitro with leaching liquids of 4 different kinds of dental alloys, Au alloy (group A), Ag-Pd alloy(group B), Co-Cr alloy(group C) and Ni-Cr alloy(group D). The RPMI1640 cell medium containing 10% fetal calf serum was served as a control(group E). The effects of these alloys on the expression of caspase-3, 8, 9 of L929 cells were examined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry method. Results After 48 h culture, the mRNA levels of caspase-3 and caspase-9 demonstrated significant differences between the groups expect group A and group E. The mRNA levels of caspase-8 had no change in all groups. The expression of caspase-3 and caspase-9 were significant differences between the groups expect group A and C, group B and D. The expression of caspase-8 had no change in all grotps.</p><p><b>CONCLUSION</b>The leaching liquids of 4 different kinds of dental alloys expect Au alloy may induce cell appotosis through mitochondrion pathway.</p>
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Animals , Mice , Apoptosis , Chromium Alloys , Dental Alloys , Fibroblasts , Materials TestingABSTRACT
This study was directed to the effects of macrophage-colony stimulating factors (M-CSF) concentration, recerptor activator of nuclear factor kappaB ligand (RANKL) concentration and M-CSF preinduction on osteoclastogenesis and the related resorption function. Bone marrow mononuclear cells were isolated and were divided into 4 groups. Group A underwent osteoclastogenic induction with the use of 30 ng/ml M-CSF and 50 ng/ml RANKL, while Group B received 50 ng/ml M-CSF and 100 ng/ml RANKL treatment. Both C and D Group underwent preinduction with the use of 30 ng/ml M-CSF for 3days, and then they were treated with 30 ng/ml M-CSF and 50 ng/ml RANKL, 50 ng/ml M-CSF and 100 ng/ml RANKL, respectively. Osteoclastogenesis was examined by TRAP staining 6 days after induction, and dentin resorption lacunae were detected by Scanning Electron Microscope 9 days after induction. TRAP positive multinuclear cells were observed in all groups of cells, and resorption lacunae were formed in all of them. However, more TRAP positive multinuclear cells were observed and more large resorption lacunae were detected in groups B and D than in groups A and C, respectively. The number of TRAP positive cells, number of resorption lacunae and lacuna areas in groups C and D were also greater than those in groups A and B, respectively. Higher concentration of M-CSF and RANKL and preinduction with M-CSF may benefit osteoclastogenesis and increase resorption function of osteoclast.
Subject(s)
Animals , Mice , Bone Marrow Cells , Cell Biology , Cell Culture Techniques , Methods , Cell Differentiation , Cell Proliferation , Cells, Cultured , Culture Media , Pharmacology , Leukocytes, Mononuclear , Cell Biology , Macrophage Colony-Stimulating Factor , Pharmacology , Osteoclasts , Cell Biology , RANK Ligand , PharmacologyABSTRACT
OBJECTIVE To explore the method and effect of endoscopic technique on maxillofacial benign tumor.METHODS Ten patients visiting our hospital from January to December 2007 and diagnosed as maxillofacial benign tumor were recruited in this study.The tumor of the patients were composed of 4 sebaceous glands,3 liparomphalus,3 epidermoid cysts.All of them were treated with endoscopic technique.The surgical approach was all in hair line or behind ear lobe and the incision was about 1cm. Subcutaneous tunnel was prepared.The operations were guided by the endoscope and helped with selfmade tritus skin expandor.RESULTS The operations were performed with an average duration of 45 minutes. Patients were all satisfied with the post operative results. CONCLUSION Endoscopic technique could well be applied in surgery of maxillofacial benign tumor.