Autophagy and oxidative stress, which are closely related, play important roles in cellular stress response, defense function, and damage. Arsenic is one of the chemical pollutant, which is widely distributed in natural environment. International agency for research on cancer (IARC) has made it clear that arsenic and its compounds are carcinogens. However, the mechanism of carcinogenesis induced by arsenic still remains obscure. Recently, researchers have found that autophagy and oxidative stress play an important role in the process of arsenic carcinogenesis. In this paper, we have reviewed the types and regulation of cellular autophagy, the roles of autophagy and oxidative stress in tumorigenesis, and the effects of arsenic on carcinogenesis.

Arsenic is one of the important metalloid elements, which is widely distributed in nature. Arsenic can cause many health hazards. However, the toxic mechanisms of arsenic have not yet been fully understood. In recent years, many studies have shown that epigenetic regulation and control mechanism is associated with arsenic toxicity. Histone modification is an important epigenetic regulation and control mechanism, changes in its patterns may be one of the mechanisms by which arsenic alters the gene expression. We reviewed the effects of arsenic on regulation of histone methylation, acetylation, phosphorylation and ubiquitination.

Objective To understand the dynamic conditions after reaching the stage goal of elimination of iodine deficiency disorders (IDD) in Wenzhou, and to provide a scientific basis for prevention and treatment of IDD. Methods Three counties that the annual consumption rate of qualified iodized salt < 80% in 2014 and had the prevalence of endemic cretinism in history, Cangnan, Taishun and Yongjia, were selected as high risk monitoring areas. Three townships were selected in each area, and two primary schools were selected from each township, and 40 children urine samples were collected in each school (half male and half female) and the age of children were 8-10 years old. And near the location of these primary schools, we randomly selected 10 pregnant women in each village, and estimated the urinary iodine level and salt iodine concentration, respectively. The examination of thyroid by B ultrasound was performed in children by provincial professionals. Urinary iodine was determined using the arsenic cerium catalytic spectrophotometric method (GB/T 13025.7-2012). Salt iodine was determined by direct titration. Results Endemic cretinism case was not found in this survey, total goiter rate of 8-10 years old children was 2.04%(16/783). The median of urinary iodine was 116.1 and 108.2 μg/L, respectively, in 8 - 10 years old children and pregnant women. Iodized salt coverage rate was 90.48%(171/189), the intaking rate of qualified iodized salt was 84.66% (160/189). The concentration of pregnant women urinary iodine and salt iodine was positively correlated (r=0.54, P< 0.05). Conclusions Children's iodine nutrition is in the appropriate level, but pregnant women are in iodine definciency in Wenzhou City.

Activation of the transcription factor NF-E2-related factor 2 (Nrf2)-signaling pathway is an adaptive response to environmental and endogenous stresses and serves to render animals resistant to chemical carcinogenesis and other forms of toxicity. However, overexpression of Nrf2 has been recognized to promote oncogenesis and resistance to chemotherapy. The application of Nrf2 in tumor chemoprevention and treatment has also become a hot topic. This review focuses on the dual roles of Nrf2 in tumorigenesis and the application of Nrf2 in tumor chemoprevention and treatment.

Endemic dental fluorosis has been reported in some regions of the world. China seemed to have high prevalence of endemic dental fluorosis, especially in southwest China. It is now most likely that excessive fluoride intake during enamel development play a key role in the pathogenesis of dental fluorosis. However, excessive intake of fluoride-induced cellular and molecular mechanisms of dental fluorosis are not entirely conclusive. Scholars at home and abroad have made a lot of research on pathogenesis of enamel fluorosis by using various experimental techniques. More recent studies mainly suggest that endoplasmic reticulum stress and calcium overload-associated apoptotic pathway may participate in fluoride excess-evoked pathogenesis of dental fluorosis. Furthermore, the functional changes of enamel matrix protein and protease activity may be involved in the pathological event. This paper summarized the recent research progress on this topic.

Objective To analyze the radiographic characteristics of right hand X-ray film of adult patients with Kaschin-Beck disease (KBD) in Qinghai Province, to understand the most affected locations in adult KBD. Methods According to the criteria of KBD diagnose (WS/T 207-2010), 111 cases of patients were taken X-ray films of right hands. Joint space narrow, joint deformity, subchondral sclerosis, osteophyte, coarse and irregularity of joint, marginal retraction sign and capsule changes were chosen as the descriptive indexes, and these indexes were analyzed with SPSS 17.0. Results A total of 111 cases adult patients with KBD were examined right hand by X-ray, abnormality on X-ray film were 103 cases, the abnormal rate was 92.79%. The most affected fingers were Ⅱ- Ⅳphalanx bones, Ⅱphalanx bones accounted for about 92.23% (95/103), Ⅲ phalanx bones accounted for about 99.03% (102/103), and Ⅳ phalanx bones accounted for about 99.03% (102/103). There was significant difference of the abnormality between th e proximal phalanx and the middle phalanx among the Ⅱ - Ⅳ phalanx bones(χ2=79.33, P<0.05). Abnormal numbers of joint deformity, marginal retraction sign, coarse and irregularity of joint, osteophyte, capsule changes and joint space narrow in the proximal phalanx were 212, 7, 134, 47, 15 and 115 in Ⅱ - Ⅳ proximal phalanx, respectively; while the abnormal numbers of joint deformity, marginal retraction sign, coarse and irregularity of joint, osteophyte, capsule changes and joint space narrow in the middle phalanx were 77, 37, 137, 26, 19 and 126 in Ⅱ - Ⅳmiddle phalanx, respectively. Conclusion The Ⅱ - Ⅳ phalanx bones of right hand are the most affected locations in adult KBD.

Objectives To study the prevailing status of coal-burning type endemic fluorosis in Fuyuan County of Yunnan Province, and to provide a scientific basis for fluorosis control and prevention. Methods In 2013, five towns were selected from the villages and towns which the defluoridation stove project was implemented and by the end of 2007 defluoridation stove rate was higher than 95%(including 95%), and two natural villages were selected in each township to carry out the investigation. Dental fluorosis was examined of all children aged 8 to 12 of survey points. At least 20 people were selected in each village. At the same time, 20 copies of instant urine samples were collected from these children of half male and half female, and urinary fluoride was determined. Then five natural villages were sampled from all survey points, and permanent residents were divided into25-,35-,45-,55-and≥65groups according to age. Six people were selected from each group with male and female in half who were conducted examination of adult skeletal fluorosis by X-ray. Dental fluorosis diagnosis was based on theDental Fluorosis Diagnosis(WS/T 208-2011). Urinary fluoride determination was done in accordance withUrine-Determination of Fluoride-Ion Specific Electrode Method(WS/T 30-1996). Skeletal fluorosis diagnosis was carried out according to Diagnostic Criteria for Endemic Skeletal Fluorosis (WS 192-2008). Results A total of 556 children aged 8 to 12 were monitored, the detection rate of dental fluorosis was 41.55%(231/556), the dental fluorosis index was 0.78. The very mild, mild, moderate and severe proportions of children's dental fluorosis were 20.50%(114/556), 17.09%(95/556), 3.60%(20/556) and 0.36%(2/556), respectively, given priority to very mild. The prevalence of dental fluorosis in children was increased with increasing age (χ2=74.27, P<0.05). One hundred and ninety-three copies of child urine samples were tested, the geometric mean of urinary fluoride was 0.62 mg/L, and the urinary fluoride contents were between 0.10-2.93 mg/L. A total of 116 adults were examined, and the detection rate of skeletal fluorosis was 9.48%(11/116). Detected cases of skeletal fluorosis was given priority to mild (9 cases, accounted for 81.81%), more men cases [16.36% (9/55)] than those of women [3.28% (2/61), χ2 = 5.77, P< 0.05]. Conclusion The hazard of coal-burning type fluorosis has been reduced in Fuyuan County , the affect of defluoridation stove project is obvious.

Objectives To monitor the residents prevalence of endemic arsenism in the disease affected areas in Inner Mongolia, so as to provide feasible suggestions for control of arsenism in the future. Methods Monitoring data were obtained from the Project of Endemic Disease Prevention Granted by Central Government in 2010 - 2012, and the conditions of arsenism patients from 38 endemic arsenic villages were analyzed among different year, age and gender. Results The detection rate of arsenism of the 38 surveillance villages was 7.38%(517/7 004) in 2010, 7.10%(482/6 784) in 2011 and 6.62% (431/6 514) in 2012. The arsenism patients of mild;moderate and severe cases from 2010 to 2012, accounted for 74.47% (385/517), 74.27% (358/482), 75.17% (324/431); 16.83% (87/517), 16.60% (80/482), 15.78% (68/431) and 8.7% (45/517), 9.13% (44/482), 9.05% (39/431), respectively. For skin lesions, the detection rates of keratosis, pigmentation and depigmentation from 2010 to 2012, were 8.08%(566/7 004), 7.90%(536/6 784), 7.77%(506/6 514);3.27%(229/7 004), 3.29%(223/6 784), 2.87%(187/6 514) and 6.68% (468/7 004), 6.63% (450/6 784), 5.82% (379/6 514), respectively, showed a declining trend. It also showed a declining trend with age, and the patients were mainly 40 years old people and older, and the highest detection rate was in the 60- 70 years old group[15.54%(143/920)、14.72%(135/917)、13.36%(136/1 018)]. For gender distribution, the detection rate of the three years was higher in male than female [male 8.24%(300/3 639), 7.99%(283/3 542), 7.71%(260/3 372);female 6.45%(217/3 365), 6.14%(199/3 242), 5.44%(171/3 142),χ2=8.24, 8.77, 13.54, all P〈0.01]. Conclusion There is no big change of arsenism conditions in 2010-2012, with a slight declining trend.

Objective This study aims to define the effects of hypothyroidism on c-fos and c-jun mRNA expression in rat testes to provide a theoretical basis for prevention and control of iodine deficiency disorders (IDD). Methods According to body weight (200 - 240 g), 20 Wistar male rats were divided into control group and hypothyroidism group (1 ml/100 g, 0.1% propylthiouracil by intragastric administration) by digital table. There were 10 male rats in each group and body weight was observed every 3 days. After 60 days, all rats were killed. The levels of thyroid hormones [total triiodothyronine (TT3), total thyroxine (TT4), and thyroid stimulating hormone (TSH)] were measured by radioimmunoassay. The mRNA expression levels of c-fos and c-jun in testes were detected by real-time quantitative PCR. Results Compared with control groups [(298.20 ± 12.15), (344.00 ± 13.73) g], the weights of hypothyroidism groups in 30 days [(239.00 ± 15.02) g] and in 60 days [(232.67 ± 17.86) g] were significant decreased (t=7.704, 11.380, all P<0.05). The levels of TT3 [(373.32 ± 101.31) ng/L] and TT4 [(4.00 ± 0.89) × 103 ng/L] in serum of hypothyroidism group were found to be significantly decreased, whereas the level of TSH [(5.77 ± 0.89) × 103 U/L] was increased in comparison with those of the control groups [(1 000.01 ± 273.53) ng/L, (44.33 ±7.84) × 103 ng/L, (1.87 ± 0.70) × 103 U/L, t = 5.262, 12.520, 8.413, all P< 0.05]. Compared with control group (1.00 ± 0.08, 1.01 ± 0.04), the c-fos and c-jun mRNA expression (0.67 ± 0.03, 0.75 ± 0.02) of hypothyroidism group was significant decreased (t = 12.382, 13.784, all P < 0.05). Conclusion Hypothyroidism may reduce mRNA expression levels of testicular c-fos and c-jun, and then damage the reproductive system in male rats.

Objective The purpose of this study was to study the correlation between dental fluorosis, saliva and plaque fluoride levels and urinary fluoride values in adolescents dental fluorosis. Methods A middle school was chosen as a survey point in the study. Two hundred adolescents were examined the degree of dental fluorosis by Dean's method. These adolescents were divided into four groups according to the severity of fluorosis (n = 52, 40, 28 and 80). Fluoride ion specific electrode was used to measure the fluoride levels in dental plaque, saliva, urinary and drinking water. The differences were analyzed b y ANOVA. Correlation of the fluoride levels between dental plaque, saliva, urine and the degree of dental fluorosis were analyzed by the method of multiple linear regression. Results The average fluoride content of drinking water was (2.20 ± 0.40) mg/L. Compared with controls, the fluoride concentrations in dental plaque, saliva and urine were higher in light, medium and severe dental fluorosis groups [(1.55 ± 0.88), (1.94 ± 0.77), (2.74 ± 0.83) than (0.32 ± 0.20) mg/L; (4.44 ± 1.62), (8.09 ± 0.93), (10.72 ± 0.99) than (0.02 ± 0.01) mg/L;(31.77 ± 6.09), (57.98 ± 1.83), (65.98 ± 2.78) than (13.06 ± 2.11) μg/g, all P<0.05]. Urinary fluoride was correlated with fluoride in saliva and dental plaque (r=0.245, 0.440, all P<0.05). Saliva fluoride was correlated with fluoride in dental plaque (r=0.849, P<0.01). The degree of dental fluorosis was correlated with fluoride in urine and saliva (r = 0.497, 0.896, 0.924, all P< 0.01). The multiple linear regression equation between fluoride in urine and the degree of dent al fluorosis, fluoride in dental plaque and saliva was as follow: y = 1.357 + 1.618x1 + 0.001x2 - 0.331x3 ± 0.69. Conclusions The metabolism of fluoride in body is related with oral fluoride repository in adolescents dental fluorosis. Fluoride in urine is influenced by plaque fluoride level, saliva fluoride concentration and the degree of dental fluorosis.