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Objective:To investigate the effect of the leaching liquids of the pure titanium porcelain crowns with barium titanate coating on the proliferation of L929 cells,and to evaluate its cytotoxicity level.Methods:The L929 ceils were cultured in vitro with leaching liquids of titanium porcelain specimens with barium titanate coating (group A),and titanium porcelain specimens(group B) for 1,3 and 5 days respectively.RPMI1640 containing 10％ fetal bovine serum and 1％ phenol was served as the negative(group C) and positive control group(group D),respectively.MTT method was used to test the effects of barium titanate coating on the proliferation of mouse fibroblast L929 cells,the cytotoxicity of the 4 groups was graded.Results:L929 cells of the group showed normal morphology and vigorous growth except group D.During the whole experiment,the absorbance values of group A was greater than that of group C(P ＜0.05).The cytotoxic gradation of group A grade 0.Conclusion:Titanium porcelain specimens with barium titanate coating has a good cytocompatibility.
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Objective To explore the optimum concentration of bioactive glass that promotes early enamel caries remineralization. Methods Fresh bovine incisors were selected and used for enamel specimen preparation. All specimens were randomly divided into two groups:micro hardness group and fluorescence group. Both groups were further divided into 3%, 6%and 9%groups. These specimens were placed in containers with demineralization liquid at 37℃for 72 hours. Then they were treat with 3%, 6%and 9%bioactive glass solution respectively twice a day for 5 minutes each. Samples in all three groups were dipped circularly into an artificial demineralization solution and an artificial saliva solution for 15 days. The mi?crohardness of enamel surface was measured before and after demineralization and remineralization. The different value of microhardness before and after remineralization was calculated. The thickness of fluorescence beneath the surface of early enamel caries was observed to evaluate the extend of remineralization effect. Results The difference in value of micro hard?ness in 6%group was the highest while that in 3%group was the lowest. The differences were significant. The difference in value of demineralization depth in 6%group was greater than those in 3%and 9%groups (P<0.05). There was no statistical?ly significance between those in 3%group and 9%group. Conclution The optimum concentration of bioactive glass solu?tion that promotes the remineralization of early enamel caries is 6%, which is ideal for remineralization of early enamel caries.
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Objective To explore the effetc of different intensity of exercise on learning ablility and oxygen free radical metabolism in rats after cerebral ischemia-reperfusion (I/R). Methods 60 male Sprague-Dawley rats were randomly divided into sham group, I/R group, aerobic exercise preconditioning group and exhaustive exercise preconditioning group. The morphological changes of neural cells in hippo-campus were observed with HE staining, the learning ablility was assessed with shuttle box, the activity of superoxide dismutase and malo-ndialdehyde level in hippocampus were measured with hydroxylamine method and TBA method respectively 1, 3, 7 days after injury. Re-sults The number of survival neurons, active avoidance reaction and activity of superoxide dismutase decreased, and the latency of passive avoidance and malondialdehyde levels increased in all the other groups compare with the sham group (P<0.001). Further more, the number of surviving neurons, active avoidance reaction rate and the activity of superoxide dismutase were less in the I/R group than in the aerobic exercise preconditioning group (P<0.001), and more than in the exhaustive exercise preconditioning group (P<0.001), while the latency of passive avoidance and the level of malondialdehyde was more than in the aerobic exercise preconditioning group (P<0.001), and less than in the exhaustive exercise preconditioning group (P<0.001). Conclusion Regular aerobic exercise is beneficial to protect the learning ability from cerebral I/R in rats, but exhaustive exercise may be negative, which may associated with the metabolism of oxygen free radical in hip-pocampus impacted by exercise.
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@# Objective To explore the effetc of different intensity of exercise on learning ablility and oxygen free radical metabolism in rats after cerebral ischemia-reperfusion (I/R). Methods 60 male Sprague-Dawley rats were randomly divided into sham group, I/R group, aerobic exercise preconditioning group and exhaustive exercise preconditioning group. The morphological changes of neural cells in hippocampus were observed with HE staining, the learning ablility was assessed with shuttle box, the activity of superoxide dismutase and malondialdehyde level in hippocampus were measured with hydroxylamine method and TBA method respectively 1, 3, 7 days after injury. Results The number of survival neurons, active avoidance reaction and activity of superoxide dismutase decreased, and the latency of passive avoidance and malondialdehyde levels increased in all the other groups compare with the sham group (P<0.001). Further more, the number of surviving neurons, active avoidance reaction rate and the activity of superoxide dismutase were less in the I/R group than in the aerobic exercise preconditioning group (P<0.001), and more than in the exhaustive exercise preconditioning group (P<0.001), while the latency of passive avoidance and the level of malondialdehyde was more than in the aerobic exercise preconditioning group (P<0.001), and less than in the exhaustive exercise preconditioning group (P<0.001). Conclusion Regular aerobic exercise is beneficial to protect the learning ability from cerebral I/R in rats, but exhaustive exercise may be negative, which may associated with the metabolism of oxygen free radical in hippocampus impacted by exercise.
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Objective To study the pathway of apoptosis occurred in chronic liver diseases. Methods Liver biopsy specimens from 72 cases of chronic hepatitis and 29 cases of post-hepatitis cirrhosis were studied. The appoptosis related proteins, including Fas、FasL、Bax、Bcl-2、Bcl-X L and Bcl-2? were examined immunohistochemically by SP method. Ultrastructures of liver cells from 15 cases with apoptosis were studied with attention to the mitochondrial changes. Results In the chronic hepatitis group, the positive rates of expression of Fas、FasL、Bax were higher than in Bcl-2、Bcl-X L 、Bcl-2? with statistical significance (P
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Objective To investigate the role of cell mediated immunity in HBV infection.Methods tive responses of peripheral blood mononuclear cell(PBMC)to hepatitis B virus antigen HBcAg,HBehg and HBsAg were studied in 20 patients with acute hepatitis B and 23 patients with chronic hepatitis B as well as 20 heath normal donrors.Results Patients with acute hepatitis B showed stronger proliferative responses of PBMC to HBV antigen than patients with chronic hepatitis B as wdl as normal donors.The responses to HBcAg and HBeAg were stronger than that to HBsAg in both acute and chronic group.It was also found that cellular pro|ifertive response,which showed no correlation with ALT level,was significantly increased in the patients with HBV DNA+or/and HBeAg+.Conclusion The results indicate that cellular immune responses to HBV antigens exist in peripheral blood of patients with hepatitis B and potentially play an essential role not only in eliminating virus but also in the pathogenesis of hepatitis B.
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0.05). Conclusions (l)There are obvious expression of HBV antigen in the gastric mucosa of patients with chronic liver disease and cirrhosis . Its role in the pathogenesis of gastric mucosal lesion is the worthful subject to be further studied. (2) No relationship between HBV antigen and Hp antigen expression was observed in this study.