Sodium nitrite improves epithelial-mesenchymal transition of hepatoma cells in mice bearing H22 / 药学学报

This study is to report the determination of the effect of sodium nitrite induced oxygen species (ROS) on the epithelial-mesenchymal transition in hepatoma cells in mice bearing H22 and investigation of its role in hypoxia-inducible factor 1alpha (HIF-1alpha) in this process. Mice hepatocarcinoma cell line H22 was inoculated subcutaneously into right axillary of sixty male Kunming mice and then randomly divided into four groups: control group; low-dose sodium nitrite group (10 mg x kg(-1)), medium-dose sodium nitrite group (20 mg x kg(-1)) and high-dose sodium nitrite group (30 mg x kg(-1)). Sodium nitrite group was given (ig) sodium nitrite with 10-30 mg x kg(-1) x d(-1) for 21 days. Compared with control group, there was no obvious difference between the two groups in the volume or weight of xenografts, but in sodium nitrite treatment group, the activity of SOD and CAT decreased and contents of MDA or nitrite increased in tumor tissue of mice bearing H22; epithelial-mesenchymal transition (EMT) of hepatoma cells was induced, the EMT-phenotype tumors displayed a greater degree of local aggressiveness, with dissection through adjacent fascia and skeletal muscle. The increased expression of HIF-la and vimentin and declination of E-cadherin were confirmed by immunohistochemistry and Western blotting. These data indicate sodium nitrite treatment could improve the epithelial-mesenchymal transition of xenografts in mice bearing H22, which might relate to the fact that ROS mediated signal pathway increased the expression of HIF-1alpha.

Protective effects of sodium nitrite preconditioning against alcohol-induced acute liver injury in mice / 生理学报

The purpose of the present study was to investigate the effect of sodium nitrite (SN) on alcohol-induced acute liver injury in mice. Forty male C57bL/6 mice were randomly divided into 4 groups. Acute alcohol-induced liver injury group were injected intraperitoneal (ip) with alcohol (4.5 g/kg); SN preconditioning group were pretreated with SN (16 mg/kg, ip) for 12 h, and received alcohol (4.5 g/kg, ip) injection; Control and SN groups were treated with saline and SN, respectively. After the treatments, liver index (liver/body weight ratio) was determined. Colorimetric technique was performed to measure the serum alanine transaminase (ALT), aspartate transaminase (AST), liver superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities, as well as malondialdehyde (MDA) content. The pathological index of liver tissue was assayed by HE and TUNEL fluorometric staining. Using Western blot and immunohistochemistry staining, the expression of hypoxia-inducible factor-1α (HIF-1α) protein was detected. The results showed that, compared with acute alcohol-induced liver injury group, pretreatment with low doses of SN decreased liver index and serum levels of ALT and AST, weakened acute alcohol-induced hepatocyte necrosis, improved pathological changes in liver tissue, increased live tissue SOD, GSH-Px and CAT activities, reduced MDA content and apoptosis index of hepatocytes, and up-regulated HIF-1α protein level in liver tissue. These results suggest that the pretreatment of SN can protect hepatocytes against alcohol-induced acute injury, and the protective mechanism involves inhibition of oxidative stress and up-regulation of HIF-1α protein level.

Application of global positioning systems and geographic information systems in drinking water defluoridation project in Liaoning province / 中国地方病学杂志

Objective To establish information management systems of drinking water defluoridation project in water-related endemic fluorosis areas and investigate the status of drinking water defluoridation project in Liaoning, provide the basis for the development of control measures. Methods Global positioning systems (GPS)and geographic information systems(GIS) were used in the study in August 2006 - July 2008. Water defluoridation projects of 1234 in 48 counties(cities, districts) in drinking water type of fluorosis areas were positioned. Latitude and longitude, water samples, water fluoride content were collected or tested. GIS was used to establish information management system of water defluoridation projects. Results We have established information management system for the facilities of decreasing water fluorine in drinking water type of endemic fluorosis regions in Liaoning. One thousand two hundred and thirty four defluoridation facilities distributed in east longitude between 39.39° - 43.37°,north latitude between 119.25° - 125.50°, and altitude between - 6.60 and 801.14 meter in 48 endemic fluorosis counties in 13 cities. Nine hundred and twenty seven facilities for decreasing fluorine were able to supply water regularly, accounting for 75.1% of investigated projects;29 facilities was .not yet completely rebuilt, accounting for 2.4%;278 facilities(supply water for 344 villages) were out of order or discarded for 22.5% of investigated projects.Water fluorine contents of 63 facilities were greater than 1.2 mg/L, accounting for 6.8% of investigation project.Facilities working regularly and water fluorine was in accord with hygienic standard for drinking water facilities were 70.0%. Conclusions The establishment of Liaoning province defluoridation project information management system in the whole province of drinking water type of fluorosis areas provides scientific basis for accurate decision-making on prevention and control of the disease.

Influence of MgO and TiO2 on mechanical properties of zirconia toughened alumina ceramics formed by gel-casting technique / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The objective of this study is to investigate the influence of mechanical properties and sintering performance by adding 5% weight percentage aids to nano-compound zirconia toughened alumina (ZTA) ceramics.</p><p><b>METHODS</b>Micrometer Al2O3 and nanometer ZrO2 (quality ratio 4:1) were used to get 55% volume percentage slurry. Magnesium oxide and titanium oxide were taken as aids which were 5% weight percentage of the Al2O3 and ZrO2 powder. Five groups (number 0, 1, 2, 3, 4 group) were divided according to different proportion of aids. After gel-casting, the porcelain pieces were sintered at 1150, 1200, 1300, 1400, 1450, 1500, 1600 degrees C for 2 hours. Static three-point flexure strength, line shrinkage, relative density were measured and scanning electron microscopy (SEM) was used to observe section.</p><p><b>RESULTS</b>Number 1 (MgO 1%, TiO2 4%) group had the highest bending strength. It was (401.78+/-19.50) MPa after sintering at 1600 degrees C for 2 hours and was higher than 0 group (380.64+/-44.50) MPa. Bending strength became lower than 0 group when MgO was more than 2% or more than that weight percentage of ZTA powder. When MgO content was higher than 2% or more than that weight percentage, there was no difference in relative density raising rate between each sintering assistants groups. When the sintering temperature was higher than 1200 degrees C, all groups showed obvious line-shrinkage and the groups which contained sintering assistants were all was higher than 0 group.</p><p><b>CONCLUSION</b>Adding MgO and TiO2 aids from 1% to 4% weight percentage of ZTA will promote fritting and increase ZTA nano-compound ceramics mechanical properties. Adding 2% MgO aids or more than that weight percent will has no obvious help to increase the relative density raising rate of ZTA nano-compound ceramics and will degrade the mechanical properties of ZTA nano-compound ceramics.</p>

Endemic fluorosis:prevalence and prevention in Liaoning Province / 中国地方病学杂志

Objective To investigate the status of control of endemic fluorosis in Liaoning Province.Methods To investigate the prevalence rate of endemic fluorosis and water fluoride content in regions with different extent of endemic fluorosis,dental fluomsis among 8-12 years old children and clinical fluorosis at adult above 16 years old were extensively surveyed,urinary fluoride among 8-12 years old children was detected.Results We surveyed 842 undefluorided drinking water in endemic fluorosis villages and 1234 projects of improving drinking water in 1829 endemic fluorosis viflages.Water fluoride content was 0.01-7.10 mg/L in unimproved drinking water in endemic fluorosis resions,averaging(0.96±0.64)mg/L;29.2%(246/842)of the endemic fluorosis regions had a fluoride content more than 1.2 mg/L In 1234 projects of improving drinking water.drinking water fluoride content was between 0.06-7.67 mg/L.The project normally operated and having a fluoride content≤1.2 mg/L accounted for 68.31%(843/1234),while 31.69%(391/1234)of the projects did not function well.The prevalence of dental fluomsis in 8-12 years old child ren in endemic fluorosis regions was 24.4%(2960/12 127),the prevalence of clinical fluorosis among adults was 2.22%(1900/85 636).The prevalente of dental fluorosis in slight,moderate and serious fluorosis regions had remarkable statistics differences(X2＝19.25,P＜0.01).The prevalence of dental fluorosis of children in serious fluorosis regions was the highest,reaching 100%,while the prevalence of skeletal fluorosis wns 18.03%(97/538).The median of urinary fluoride was 2.01.2.00mg/L in serious and slight fluomsis regions,respectively.Conclusions Endemic fluorosis is still serious.so we need urgently to improve water in serious fluorosis regions without defluoridaton of drinking water.Endemic fluomsis resions where worn-out and closed defluoriding projects exist need defluoriding management.

Influence of ambient light and adjacent tooth in anterior tooth color measurement / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of different intensity and directions of ambient light and adjacent tooth in anterior tooth color measurement by using colorimeter.</p><p><b>METHODS</b>Fiber lite MI-150 was used as ambient illuminant and it irradiated from three or twelve o'clock direction through 45 degrees angle above. The light magnitude 0, 50, 75, 100, 125, 150 W were applied in this experiment. The values of CIE L* a* b* were measured by Minolta Chroma meter CR-321 colorimeter on the center labial surface of ten extracted human maxillary central incisors with or without adjacent teeth, then those data were analyzed statistically by using SPSS 11.5.</p><p><b>RESULTS</b>Neither different intensities nor different directions of ambient light could influence the results of color measurement by using Minolta Chroma meter CR-321 colorimeter, so did the adjacent teeth whether those were exist or not.</p><p><b>CONCLUSION</b>There is no influence of ambient light and adjacent teeth in the color measurement of anterior teeth under this experiment condition, and Minolta Chroma meter CR-321 colorimeter can be used to measure the color directly aside the chair with light.</p>