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ObjectiveLipopolysaccharide （LPS）-induced zebrafish inflammation model was used to evaluate the anti-inflammatory activity of different extracts from Lianggesan （LGS） and its component Glycyrrhiza Radix et Rhizoma. MethodDifferent polar fractions of LGS and Glycyrrhiza Radix et Rhizoma were obtained by the principle of similar miscibility. For toxicity observation， the zebrafish （3 day-post-fertilization） was exposed to different concentrations of extracts for 24， 48 and 72 h. The yolk sac of the zebrafish was microinjected with 0.5 g·L-1 LPS to establish the inflammation model， and then the embryos were soaked with different concentrations of extracts to observe their survival status at 72 h and the aggregation of neutrophils in yolk sac at 12 h after treatment. Hematoxylin-eosin staining was used to analyze the yolk sac of the zebrafish microinjected with LPS. Quantitative Real-time polymerase chain reaction （Real-time PCR） was performed to further investigate the anti-inflammatory effects and mechanisms of LGS and Glycyrrhiza Radix et Rhizoma. ResultThe toxicity of LGS and Glycyrrhiza Radix et Rhizoma was decreased with the increase of polarity， and the descending order was petroleum ether>ethyl acetate>n-butanol>water. Compared with model group， the extracts from different fractions of LGS and Glycyrrhiza Radix et Rhizoma prolonged the survival time of the zebrafish， and inhibited the recruitment and aggregation of neutrophils and decreased the infiltration of inflammatory cells in the yolk sac， among which the water fraction of LGS and the ethyl acetate fraction of Glycyrrhiza Radix et Rhizoma had the most significant effect （P<0.01）. In addition， compared with model group， the water fraction of LGS and the ethyl acetate fraction of Glycyrrhiza Radix et Rhizoma down-regulated the mRNA expression of interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α）， and suppressed the expression of toll like receptor 4 （TLR4） and nuclear factor kappa-B （NF-κB） in LPS-stimulated zebrafish （P<0.01）. ConclusionThe extracts from different fractions of LGS and Glycyrrhiza Radix et Rhizoma exerted protective effects in LPS-induced zebrafish by inhibiting the TLR4 and NF-κB signaling pathways. Moreover， in zebrafish model， the method of administration by soaking was applicable to the high-throughput screening of anti-inflammatory Chinese medicine， which was suitable for the evaluation of anti-LPS activity of Chinese medicine and the different extracts.
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Objective@#To evaluate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (Pe) on the expression of matrix metalloproteinase-9 (MMP-9) mRNA and protein as well as enzyme activity in MC3T3-E1 cells and the role of nuclear factor-κB (NF-κB) in the process, so as to investigate the expression of MMP-9 dependent signaling pathways in mouse osteoblasts induced by Pe LPS.@*Methods@#The experiment was conducted in 3 sessions: MC3T3-E1 cells were treated with various concentrations of Pe LPS (0-20 mg/L) and 10 mg/L Pe LPS for different time intervals (0-48 h). The expression of MMP-9 mRNA and protein were detected by real-time reverse transcription-PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), while the enzyme activity was detected by gelatin zymography method. The expression of MMP-9 mRNA was also detected in 10 mg/L Pe LPS treated MC3T3-El cells after pretreated with specific NF-κB inhibitor BAY 11-7082 for l h. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS 13.0 software package.@*Results@#The levels of MMP-9 mRNA and protein increased significantly after the treatment with various concentrations of Pe LPS (0-20 mg/L), which indicated that Pe LPS induced osteoblasts to express MMP-9 in dose dependent manners. The expression of MMP-9 protein increased from (5 395±362) ng/L (blank control group) to (12 684±375) ng/L (20 mg/L group). Maximal induction of MMP-9 mRNA expression was found in the MC3T3-E1 cells treated with 10 mg/L Pe LPS for 24 h. The expression of MMP-9 mRNA in the 20 mg/L group was about 7 times than that in the blank control group. After 24 h, the expression of MMP-9 mRNA decreased. Maximal expression of MMP-9 protein was found in the MC3T3-E1 cells treated with 10 mg/L Pe LPS for 48 h ([35 055±2 346] ng/L) showing the highest enzyme activity. The mRNA of MMP-9 decreased significantly after pretreatment with 10 µmol/L BAY 11-7082 for 1 h.@*Conclusions@#Pe LPS might induce the expression of MMP-9 in MC3T3-E1 cells through the signaling of NF-κB.
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Objective To observe the surface morphology of dentin irradiated by Er,Cr∶YSGG laser under anhydrous conditions and discuss the possible clinical applications of the laser.Methods 11 freshly extracted specimens (approximately 1.5 mm thick) taken from the first premolars were selected.One was regarded as the control group without any treatment and the remaining ten were divided into 5 groups whose dentin surface was irradiated by Er,Cr∶ YSGG laser with different energy (1,2,3,4,6 W) under anhydrous condition.The specimens were routinely prepared for electron microscopic scanning observation.Results As the output power increased with Er,Cr∶YSGG laser irradiation,the dentin surface was observed of the constriction of tubular lumen,and part of the tubules closed.The dentin surfaces with 3 ～6 W laser irradiation were observed thermal injury alters such as micro crack and carbonization.Conclusion 1 ～2 W anhydrous Er,Cr:YSGG laser irradiation play a more ideal and safe constriction and sealing role to dentinal tubules,and the laser is expected to be used for the treatment of dentin hypersensitivity.
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<p><b>OBJECTIVE</b>The purpose of this study was to evaluate the morphological changes of Er, Cr: YSGG laser irradiated dental hard tissues by scanning electron microscopy (SEM).</p><p><b>METHODS</b>12 freshly extracted premolars were treated with fissure bur, Er, Cr: YSGG laser at 4 watt, Er, Cr: YSGG laser at 6 watt, respectively, and then bisected transversally and longitudinally. The tooth slice were prepared with conventional methods and observed by SEM.</p><p><b>RESULTS</b>Compared with fissure bur, laser treatment resulted in a rather scaly and rough surface. The sections were free of smear layer, with open dentinal tubules. No carbonization and thermal damages were observed. The laser at 6 watt appeared rougher than at 4 watt, occasionally caused micro-cracks.</p><p><b>CONCLUSION</b>The utilizing of Er, Cr: YSGG laser can contribute to enhance the bond strength between restorative materials and dental hard tissues. It suggests that higher energy could be applied in cutting enamel, whereas the lower energy in dentin.</p>
Subject(s)
Humans , Dental Cavity Preparation , Methods , Dental Enamel , Radiation Effects , Dental High-Speed Equipment , Dentin , Radiation Effects , Hardness , In Vitro Techniques , Lasers , Microscopy, Electron, Scanning , Tooth , Radiation EffectsABSTRACT
We defined the prerequisite managing capacity of hospital directors through a comprehensive set of methods including literature review, interview of specialists and questionnaires. There were altogether 7 assessment items with 36 assessment indexes. The acquired assessment items and indexes were edited as Likert Scales and as signed to extprts concerned. The weight ofthe assessment indexes was obtained through a statistical analysis of the results. Hence the pre iluninary establishment of the system of standards for assessing the managing capacity of hospital directors.
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Objective:To evaluate the effects of Er,Cr:YSGG laser combined with NaF treatment on the acid resistance of human dental hard tissue.Methods:The enamel or dentin samples were randomly divided into four groups and prepared by different methods as follows: ①without treatment(control group),②laser irradiation(Laser group),③ treated with 20 g/L NaF solution(NaF group),④laser irradiation+ NaF solution treatment(Laser and NaF group).The samples of each group were respectively demineralized in 0.1 mol/L of lactic acid for 24 h and the calcium ion in the demineralization solution in each group was measured by atomic absorption spectrophotometry.The fluoride on the surface of the samples was examined by SED-X and the ultrastructure was investigated by SEM.Results:The concentrations of Ca~(2+) dissolved from the enamel or dentin samples in NaF,laser and NaF and laser groups were significantly lower than that in the control group(P(0.05)).Only in the NaF group,the F peak appeared.SEM observation showed the lased surface showed various patterns of microirregulation with a scaly appearance,the openings of dentinal tubules were visible,but no melting or carbonization;there were lot of particles attached to the surface of NaF treated samples;the ultrastructure of the NaF and laser-treated sample surfaces was similar to that of the laser treated.Conclusion:The combined use of laser and NaF dose not have synergetic effects on acid resistance of human dental hard tissue.
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0.05).SEM revealed that the lased enamel surface appeared various patterns of microirregularity, and there was no smear layer.Conclusion:Laser irradiation can be used to prepare the enamel before placing pit and fissure sealant.
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Using registration information on candidates for the written examination in medical synthesis, a part of the doctor qualification examination, from 1999 to 2001 as processing data, the authors made a comparative study on the composition of the candidates in the eastern, middle and western regions of the country from 7 aspects, viz. total number, category of registration for the examination, educational background, time of graduation, age, organization and rank of organization. It was found that the educational background of the candidates was on the whole very low and the number and quality of health personnel in the western region and at the grass roots level was in dire need of enhancement.
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Objective:To observe the elimination of smear layer on the dentin exposed to Er,Cr:YSGG laser with different energy and irradiating distance. Methods:The in vitro first premolar was selected and slices with 1.5 mm thickness were obtained by horizontal sectioning through the middle third of the teeth crown using a high-speed bur. Each dentinal slice was irradiated under the laser with different irradiating distance(