Objective To know the prevalence tendency of Keshan disease(KSD) under control after 10 years in Shaanxi Province, the factors that causes or relative to the disease, to provide scientific reference for disease's prevention and control. Methods Through stratified cluster sampling, based on the severity of KSD in endemic area of Shaanxi Province, 12 villages from 6 counties were randomly selected as investigation points in 2006. The people older than 3 year-old were chosen to do clinical check up and electrocardiogram tracing. Among them, suspicious or abnormal cases were asked to take chest X-ray and cardiac ultrasound. Maize and rice, hair and whole blood were randomly collected to test the selenium content, the activity of Glutathione peroxidase (GSH-Px). Results The total detection rate of potential or chronic KSD was 2.44%(139/5694), the detection rate of abnormal ECG was 9.19% (523/5692), the detection rate of cardiac enlargement from chest X-ray and cardiac ultrasound were 45.6%(72/158) and 34.5%(59/171) respectively. The average content of selenium in staple foods(wheat and corn) were[(0.045±0.036), (0.035±0.025)mg/kg, respectively]. The level of hair selenium in patients and healthy people were [(0.376±0.091), (0.384±0.077)mg/kg, respectively], with non-significant different (u=0.77, P>0.05). There were significant differences in whole blood selenium of patients, healthy people in KSD areas and healthy people in non-KSD areas[(0.071±0.017), (0.077±0.017), (0.090±0.016)mg/L, respectively; F=4.55, P<0.05), the whole blood selenium in patients lower than in healthy people in KSD areas (P<0.05), in healthy people in KSD areas lower than in non-KSD areas (P<0.05). Conclusions After the KSD condition being controlled, the situation in Shaanxi Province has become stable and exhibited a decreasing tendency. The selenium level of both internal and external environment in the endemic area increased significantly, that is the main factors of controlling disease.

Objective To explore the distribution of arsenic speciafion and to estimate the effect of arsenic on glutathione(GSH)levels in the blood and liver of mice exposed to different concentrations of inorganic AsⅢ through drinking water.Methods Mice drank water containing arsenite at concentrations of iAsⅢ of 0(contr01),25,50,100 ms/L for 6 weeks.Blood and liver were sampled to asses$the levels of inorganic arsenic(iAs),monomethylarsenic acid(MMA),dimethylarsenic acid(DMA)by the method of hydride generation trapping and ultra-hypothermia coupled with atomic absorption spectrometry,and the level of GSH by the method of 5,5'-Dithio-bis (2-Nitrobenzoic acid).Results Leveh of iAs.MMA and DMA in blood and in liver increased along with the increase of iAs concentrations in drinking water.Primary methylated index(PMI)and secondary methylation index (SMI)of liver and blood were significantly higher in exposed groups than those in control group(P＜0.05).SMI of liver in 50 mg/L exposed group[(50.45±2.94)%]was significantly higher than those in 25 mg/L and 100 mg/Lgroups[(41.68±7.09)%and(41.19±8.87)%,respectively],the difference being statistically significant(P＜0.05).The ratio of iAs.MMA and DMA in blood and liver in exposed group were 2:3:5 and 4:3:3,the percentage of level of organic arsenic(MMA+DMA)were 80%and 60%.GSH in blood and liver in exposed group decreased along with iAs concentrations in drinking water and had significant differences compared with those in control group (P＜0.05).However,levels of GSH in liver and blood did not differ significantly between exposed groups and control group(P＞0.05).Conclusions Membolism of iAs in liver is maximized when the iAs concentrations in drinking water increases to a certain level.However,the percentage of arsenic speciation in blood is different from that in liver,suggesting that other organs and tissues may be capable of methylation of inorganic arsenic.The level of GSH in liver and blood in mice is a good mark tO reflect the toxicity of arsenic.

Objective To explore the status of Keshan disease in Shaanxi province to provide a scientific basis for decision-making of prevention and control of Keshan disease. Methods Nineteen infected villages were randomly selected in 19 infected counties in the range of Keshan disease infected area in Shaanxi province in 2008 as the investigation sites. Clinical examination and electrocardiography were performed in the chosen people at every spots, chest X-ray of posteroanterior position film in 2-meter distance was taken in suspicious cardiac patients, and determining the selenium contents was also determined in the collected grain samples of the investigators. Results Of the 10 228 investigated residents in the endemic area, 110 Keshan disease patients were detected, the total detection rate was 1.08% (110/10 228). Among the 110 patients, 92 were potential Keshan disease, which accounted 0.90%(92/10 228); 18 chronic Keshan disease formed a detection rate of 0.18%( 18/10 228); no acute and sub-acute type of Keshan disease had been inspected. Potential Keshan disease patients often showed electrocardiogram abnormality of complete fight bundle branch block [48.57%(51/105)], ST-T change[ 19.05% ( 20/105 ) ], frequent premature ventricular contraction [ 10.48 % ( 11/105 ) ], left ventricular hypertrophy [ 5.71% (6/105) ], block in the anterosuperior division of the left branch[5.71%(6/105)]; Chronic of Keshan patients mostly presented atrial fibrillation [ 24.00% (6/25) ], left ventricular hypertrophy [ 20.00% (5/25) ], complete right bundle branch block [ 20.00% (5/25)]. The increase rate of cardiothoracie ratio was 18.08% (32/177). Food samples of wheat, corn, millet and rice in infected area residents were of selenium content, being (0.096± 0.028), (0.089 ±0.029), (0.087 ± 0.016), (0.047 ± 0.016)mg/kg, respectively. Conclusions Keshan disease in Shaanxi province is steadily declining, potential and chronic Keshan diseases are currently the main clinical types. Selenium content of food in endemic area has reached the level of the non-endemic area.

Objective To investigate the relationship between the patient-based questionnaires and the computed tomography (CT) staging in patients with chronic rhinosinusitis (CRS). Methods Quantitative data of 121 preoperative recruits with CRS were collected by using the Lund-Mackay CT staging system, a visual analogue scale ( VAS), sino-nasal outcome test-20 ( SNOT-20), and the medical outcome study short-form 36 items (SF-36). The patients were classified into several subgroups according to whether CRS was associated with nasal polyps (NP) or not, sex, duration of disease, and educational background.Correlation between the patient-based questionnaires and the CT staging were analyzed in the total cohort patients and subgroups. Results In the total cohort patients, there were significant correlations between SNOT-20 and SF-36 ( r = -0. 561, P ＜ 0. 01 ), SNOT-20 and VAS ( r = 0. 743, P ＜ 0. 0l ), and SF-36 and VAS ( r = - 0. 504, P ＜ 0. 01 ), however, the CT staging did not correlate with the patient-based questionnaires (P ＞ 0. 05 ). Significant but weak correlations were found between the CT staging and the patient-based questionnaires in the C RS with NP subgroup (CT vs SNOT-20, r = 0. 318, P = 0. 005; CT vs SF-36, r = - 0. 358, P = 0. 002; CT vs VAS, r = 0. 358, P = 0. 002). Compared between CRS with NP and without NP subgroup, there were statistic differences on the Lund-Mackay CT stage and the SNOT-20 and VAS scores (t value was 3.249, -2.409, -2.957, respectively, all P＜0.05). Conclusions The patient-based questionnaires correlate well with each other, but CT staging correlated significantly but weakly with the patient-based questionnaires only in the CRS with NP subgroup. Nasal polyps do not appear to be responsible for the adverse effects of CRS on quality of life.

Objective To develop a method of three-dimensional computer aided design(CAD)of post-and-core restoration.Methods Two plaster casts with extracted natural teeth were used in this study.The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models.According to the basic rules of post-and-core design,posts,cores and cavity surfaces of the teeth were designed using the tools for processing point clouds,curves and surfaces on the forward engineering software of Tanglong pmsthodontic system.Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth,premolars and molars respectively.Results Computer aided design of 14 post-and-core restorations were finished,and good fitness between the restoration and the three-dimensional digital models were obtained.Appropriate retention forms and enough spaces for the full crown restoratiohs can be obtained through this method.Conclusions The CAD of three-dimensional figures of the post-and-cort restorations can fulfill clinical requirements.Therefore they can be used in computer-aided manufacture(CAM)of post-and-core restorations.