[Surveillance on drinking-water-born endemic fluorosis in China, 2013].

OBJECTIVE: To investigate the prevalence of fluorosis and related control measures on drinking water type of endemic fluorosis in China. METHODS: According to the national program- "Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis" , 136 counties were selected in 29 provinces, autonomous regions and municipalities. Three epidemic villages were randomly selected as fixed monitoring sites in each county. Dental fluorosis of all the children aged 8-12 living in the villages under the monitoring program, was identified under the ariteria from "Diagnosis of dental fluorosis" (WS/T 208-2011). Operating conditions and contents of fluoride in all the'water-improved projects' were investigated. Contents of fluoride in drinking water were tested in villages without the 'water-improved projects'. "Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to detect the water fluoride. RESULTS: The overall prevalence of dental fluorosis among children aged 8-12 in all the villages under monitor program, was 28.58% (7 950/27 817), with the dental fluorosis index (DFI) as 0.58. Among them, the prevalence was 22.28% (3 917/17 583) and DFI was 0.44 in the'water-improved projects' villages that under normal operation and with qualified fluoride contents. The prevalence appeared as 38.74% (1 926/4 971) with DFI as 0.84 in those villages with 'water-improved projects' but mal-operated or with excessive fluoride. The prevalence was 40.03% (2 107/5 263), and DFI was 0.81 in those villages without 'water-improved projects'. The prevalence rates of dental fluorosis in children from the three types of endemic areas were significantly different. For 'water-improved projects', the normal opration rate was 93.77% (286/305) and the qualification rate of fluoride content was 76.77% (228/297). CONCLUSIONS: Dental fluorosis in children living in the drinking-water-born endemic fluorosis areas was on the edge of epidemics in China. Effective improvement on the quality of drinking water can significantly reduce the severity of dental fluorosis in children. The rate of proper operation on 'water-improved projects' was near to 95% in the endemic area. However, rate that met the criteria on qualified fluoride contents of these projects was still below 80%.

Selenoprotein P and Yunnan endemic sudden cardiac death--an ecological study.

The aim of the present study was to explore the role of selenoprotein P (SePP) in the etiology of the endemic sudden cardiac death in Yunnan, China. The levels of SePP of 124 subjects and glutathione peroxidase (GPx) of 119 subjects were measured. The subjects were from the old and new endemic areas and non-endemic areas. The levels of SePP and GPx of the subjects of the old endemic area were significantly higher than those of the subjects of the new endemic area and the non-endemic areas, respectively. The Pearson's correlation among SePP, GPx, and the number of the incident cases of the disease were statistically significant. These correlations show that there is an inverse relationship among the number of patients and the levels of SePP (r = - 0.9800, P = 0.0200) and GPx (r = - 0.961, P = 0.009). The results show that selenium deficiency might play an important role in the incidence of the disease.

Analysis of glutathione peroxidase 1 gene polymorphism and Keshan disease in Heilongjiang Province, China.

Keshan disease (KD) is an endemic cardiomyopathy associated with selenium deficiency. Recent studies indicate that glutathione peroxidase 1 (GPx1) mutation decreases GPx activity in myocardial cells and increases the risk of KD. To further clarify the correlation between GPx1 polymorphism and KD, we analyzed GPx1 polymorphism, blood selenium levels and GPx activity in KD patients and healthy controls in Heilongjiang Province. Four and 24 new mutation loci in the promoter and the exon region, respectively, of the GPx1 gene were found in the subjects, in contrast with the previously reported loci. There were no significant differences in the mutation frequency of these loci between the KD group and controls (chi-square test; P > 0.05). However, the mutation frequency of exon 474 was higher in the KD group (7/36) than in controls (2/41), and GPx activity was lower in the mutation group (90.475 ± 23.757 U/L) than in the non-mutation group (93.947 ± 17.463 U/L). Further investigation is necessary to clarify a possible causality between GPx1 exon 474 mutation and KD.