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Objective@#To investigate the effect of the multi-material artifact reduction (MMAR) algorithm of spectral CT in reducing the beam hardening artifacts in dental restoration material.@*Methods@#Three-unit fixed bridge restorations were fabricated on the first to third molars in pig jaw. Gold alloy, zirconia, cobalt chromium alloy, nickel chromium alloy and pure titanium were used as materials for these fixed bridges. After restoration delivery, the pig jaw was scaned using energy spectrum CT machines. Images in regular 120 kVp scan mode were used as conventional group, and reconstructed single-energy horizontal images of 80, 90, 100, 110, 120, 130 and 140 keV in energy spectrum scanning mode were used as energy spectrum group, and reconstructed images applied MMAR technology in energy spectrum scanning mode were used as energy spectrum MMAR group. Each group was scanned 10 times to measure CT value and noise of muscles around dental prosthetic materials and adjacent non-artifact layers. Artifact index was calculated. Two radiologists scored the image quality of each group subjectively. Kruskal Wallis rank sum test was used to compare the difference of image noise, artifact index and subjective score among the control group and the best keV condition in the energy spectrum group and the energy spectrum MMAR group.@*Results@#The image noise of energy spectrum group and energy spectrum MMAR group decreased gradually with the increase of single energy level. The artifact index of pure titanium restorations in conventional group, energy spectrum group and energy spectrum MMAR group were 71.0±8.0, 21.4±2.7 and 14.7±2.7 respectively, and these values were significantly lower than those of other materials in the same group (P<0.05). The subjective image quality scores in energy spectrum MMAR group were as follows: 3.0±0.2 for gold alloy, 4.3±0.5 for zirconia, 3.0±0.4 for cobalt chromium alloy, 3.1±0.4 for cobalt chromium alloy, and 4.6±0.5 for pure titanium. These scores were significantly smaller than those in the conventional group (P<0.05). There was no significant difference in noise between energy spectrum group and energy spectrum MMAR group (P>0.05), and the noise values in energy spectrum group and energy spectrum MMAR group were significantly lower than that in the conventional group (P<0.05).@*Conclusions@#Artifacts of pure titanium is minimal. Energy spectrum CT combined with MMAR technology can effectively reduce the artifacts of gold, zirconia, cobalt-chromium alloy, nickel-titanium alloy and pure titanium. This technique can be used as an effective method to remove artifacts of dental prosthesis.
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Objective To evaluate the application value of superb micro-vascular imaging (SMI) technology in gastric cancer.Methods Data of color Doppler flow imaging (CDFI) and SMI of 69 patients with gastric cancer confirmed by pathology were analyzed retrospectively.The positive rate in displaying the blood flow,the thickness of gastric carcer lesion with blood flow signal and the grade of blood flow obtained with CDFI and SMI were compared.Results The positive rate of blood flow was 75.36％ (52/69) of CDFI and 95.65％ (66/69) of SMI,respectively.The difference of positive rate between the two methods was statistically significant (x2 =11.461,P=0.001).The thickness of gastric cancer lesion with blood flow signal measured with CDFI was (19.92±4.54)mm,and that measured with SMI was (16.92±5.77)mm (t=2.048,P=0.043).There was statistical difference of the grades of blood flow between SMI and CDFI (Z=5.354,P＜ 0.001).Conclusion SMI technology is more sensitive for the low flow velocity of micro vessels signal in gastric carcinomas compared with CDFI,which can provide valuable reference for clinic.
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Objective:To study the change ofTIZ expression in epithelial ovarian cancer cells.Methods:HO8910 cells were transinfected with siRNA to inhibit the expression ofTIZ. pcDNA3.1-TIZ vectors were combined to increase theTIZ expression level.The cell viability, colony forming efficiency and cycle distribution ofHO8910,HO8910/NC,HO8910/pcDNA3.1-NC,HO8910/TIZ-573 andHO8910/pcDNA3.1-TIZ were compared, and the invasion rate, migration rate and adhesion rate between5 groups of cells were compared.Results:Compared with those ofHO8910,HO8910/NC andHO8910/pcDNA3.1-NC, the cell viability, colony forming efficiency and cell cycle distribution ofHO8910/TIZ-573 were increased, while the indexes ofHO8910/pcDNA3.1-NC were decreased with statistical significant difference(P0.05). Conclusions:The expression ofTIZ can inhibit the proliferation of epithelial ovarian cancer cells.
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BACKGROUND: The molecular mechanism and core regulatory network of deep vein thrombosis are not fully clarified yet.OBJECTIVE: To explore the roles of oxidative stress and Rac1/2 in rat deep vein thrombosis.METHODS: Deep vein thrombosis model in SD rats was established by a champing method femoral veins clamping combinedwith fixation of the lower extremity with plaster. The incidence and serious degree of thrombus were observed by dissecting ratfemoral vein at different time points (2.5 and 25 hours after modeling). The model rats were divided into pre-thrombogenesisgroup (2.5 hours after modeling), thrombogenesis group (25 hours after modeling) and non-thrombogenesis group (25 hours aftermodeling). Then total RNA and protein were extracted from the femoral venous wall tissues.RESULTS AND CONCLUSION: Colorimetry results showed that compared with the non-thrombogenesis group, theconcentration of malondiadehyde in rat femoral vein wall tissues of the thrombogenesis group was the highest (P < 0.05), followedby that of the pre-thrombogenesis group (P < 0.05). The concentrations of total superoxide dismutase and glutathione reductasein the thrombogenesis group were the lowest, followed by those in the pre-thrombogenesis group (P < 0.05). The results of genechip hybridization analysis and real-time PCR showed that compared with the non-thrombogenesis group, the expressions ofRac1 and Rac2 in rat femoral vein wall tissues of thrombogenesis group increased the most, followed by that of thepre-thrombogenesis group (P < 0.05). These findings indicate that the up-regulation of malondialdehyde and Rac1/2 as well asthe activity decrease of total superoxide dismutase and glutathione reductase may lead to the formation of deep venousthrombosis.
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BACKGROUND: At present, the basic underlying molecular mechanism regulating the interactions among venous endothelial cells, platelets, leukocytes, and promoting local deep vein thrombosis microenvironment formation, still remains unclear, and there is no ideal method for early diagnosis of deep vein thrombosis. OBJECTIVE: To study the underlying role of nuclear factor kappa B1 and tissue factor in rats with deep vein thrombosis. METHODS: A total of 67 Sprague-Dawley rats were randomly divided into control group (n=10) and model group (n=57). Deep vein thrombosis model was established by a clamping and sewing method in femoral vein combined with cast fixation. The incidence and serious degree of thrombus were observed by dissecting rat femoral vein in different time points (2.5 and 25 hours after modeling). The model group was further divided into pre-thrombogenesis group (2.5 hours after modeling), thrombogenesis group (25 hours after modeling) and non-thrombogenesis group (25 hours after modeling). Then total RNA was extracted from the localized femoral venous endothelial tissue. The candidate genes, associated inflammation and thrombosis, were screened by a special gene chip. Then the gene expression of nuclear factor kappa B1 and tissue factor was further identified by real-time polymerase chain reaction. RESULTS AND CONCLUSION: Pre-thrombogenesis group had no thrombogenesis, while thrombogenesis group have 23 cases with thrombosis and non-thrombogenesis group have 22 cases without thrombosis. The results of gene chip hybridization analysis and real-time PCR found that the mRNA expression of nuclear factor kappa B1 and tissue factor in rat femoral vein endothelial tissue were significantly up-regulated at 2.5 hours after modeling (pre-thrombogenesis group was higher than control group) (P < 0.05), and continued up-regulating at 25 hours after modeling (thrombogenesis group was higher than the pre-thrombogenesis group, non-thrombogenesis group and control group) (P < 0.05). The results from present study indicate that up-regulating expressions of nuclear factor kappa B1 and tissue factor in local femoral venous endothelial tissue of rat deep vein thrombosis models may play a key role in initiating venous thrombosis.