Nail Selenium Level and Diabetes in Older People in Rural China.

This cross-sectional study aimed to examine the association between selenium levels and diabetes in an older population with life-long natural exposure to selenium in rural China. A total of 1856 subjects aged 65 years or older from four Chinese rural counties with different environmental selenium levels were evaluated. Analysis of covariance models and logistic regression models were used to examine the relationship between nail selenium levels and serum glucose, serum insulin, insulin resistance [using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)], and the risk of diabetes. The mean nail selenium level was 0.461 µg/g and the prevalence rate of diabetes was 8.3% in this population. The mean nail selenium level was significantly higher in the group with diabetes than in the group without diabetes (P<0.0001). The adjusted odds ratios for diabetes were 2.65 (95% CI: 1.48 to 4.73), 2.47 (95% CI: 1.37 to 4.45), and 3.30 (95% CI: 1.85 to 5.88) from the second selenium quartile to the fourth quartile, respectively, compared with the first quartile group. The mean serum glucose and HOMA-IR in the higher selenium quartile groups were significantly higher than those of the lowest quartile group. However, no significant differences in insulin were observed among the four quartile groups. A long-term, higher level of exposure to selenium may be associated with a higher risk of diabetes. Future studies are needed to elucidate the association between selenium and insulin resistance.

[Spatial distribution characteristics of iodine in drinking water in Shandong province between year 2008 and 2010].

OBJECTIVE: To detect the spatial distribution characteristics of iodine in drinking water of residents in Shandong province with spatial autocorrelation analysis. METHODS: The county-based study set Shandong province as a research site. A total of 108 164 water samples from 140 counties were collected. The drinking water iodine data in county-level city between 2008 to 2010 were obtained from Shandong Institute of Prevention and Control for Endemic Disease and was merged with an electronic map to build a spatial database. Global and local Moran's I index were calculated, respectively, and spatial autocorrelation and cluster range of iodine distribution in drinking water in Shandong province were studied by SaTScan software. RESULTS: All counties were further grouped according to the "criteria of delimitation for IDD endemic areas" and "determination and classification of the areas of high water iodine and the endemic areas of iodine excess goiter", and 90 counties were iodine deficiency (< 10 µg/L), 31 were iodine suitable (10 - 150 µg/L), and 19 (> 150 µg/L) were high iodine. For the overall study area, the iodine distribution in drinking water in Shandong province existed spatial autocorrelation (Moran's I = 0.52, Z = 7.4, P < 0.01). For the local scale, the drinking water iodine in 18 counties of Dezhou, Liaocheng and Heze city in western Shandong province was clustered, the local Moran's I were between 0.22 - 1.00 (P < 0.01), which were all high-high clusters, indicating the positive spatial correlation. Spatial analysis using SaTScan software detected two cluster areas including 20 counties, which the centers located in Xiajin and Dingtao county, the cluster radiuses were 57.47 km and 65.58 km respectively. The analysis results were consistent with the results of local spatial autocorrelation. CONCLUSION: There are apparent spatial autocorrelation and strong spatial heterogeneity existed in the iodine distribution in drink water in Shandong province.

[Study on genetic polymorphism of human mismatch repair gene hMLH1 and susceptibility of papillary thyroid carcinoma in Chinese Han people].

OBJECTIVE: To explore the associations between the single nucleotide polymorphism of human mismatch repair gene hMLH1 and the papillary thyroid carcinoma (PTC) in Chinese Han people. METHODS: A hospital based 1:1 matched case-control study was carried out. The single nucleotide polymorphism (-93G > A, 1151T > A and 655A > G) for 204 pairs of cases with PTC as well as healthy controls was identified by PCR-RFLP, PCR-ASO and DNA sequencing. RESULTS: With univariate analysis, we found that compared to 1151TT genotype, the TA genotype could increase the PTC risk marginally, with odds ratio (OR) of 2.15 (95%CI: 0.99 - 4.85); While the mutant genotype TA + AA could increase the PTC risk statistically significant, with OR of 2.15(95%CI: 1.02 - 4.69). With 2 x 4 cross-over study, we found that compared to -93GG and 1151TT genotypes, individuals with both -93GA + AA and 1151TA + AA could increase the PTC risk marginally, with OR of 2.50 (95%CI: 0.96 - 6.67); While, compared to 655AA and 1151TT genotypes, individuals with both 655AA and 1151TA + AA could increase the PTC risk statistically significant, with OR of 2.50 (95%CI: 1.02 - 4.73). Multivariate and conditional logistic regression analysis showed the genotype of 1151TA, the history of receiving CT diagnosis, the history of tumor, the negative life events and eating seafood frequently could increase the risk of PTC, with OR of 6.79 (95%CI: 3.18 - 14.49), 3.35 (95%CI: 1.93 - 5.80), 39.03 (95%CI: 3.70 - 41.60) and 3.98 (95%CI: 1.81 - 8.73); While, eating fruit frequently could decrease the PTC risk. CONCLUSION: The 1151TA + AA genotype, the history of receiving CT diagnosis, the history of tumor, the negative life events and eating seafood frequently were the risk factors of PTC, while eating fruit frequently was the protective factor.

[Association of genetic polymorphisms and haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma].

OBJECTIVE: To explore the relationship of the genetic polymorphisms and the haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma (PTC) in Chinese Hans. METHODS: A hospital based 1:1 matched case-control study was carried out. The polymorphisms for 204 pairs of PTC cases and healthy controls were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific oligonucleotide (PCR-ASO) assays. RESULTS: (1) The PTC risk was marginally increased in the hMLH1 1151TA genotype, with odds ratio (OR) of 2.15 (95%CI: 0.99-4.85); the PTC risk was significantly increased in the mutant genotype 1151TA+AA, with OR of 2.15 (95%CI: 1.02-4.69); (2) The haplotypes of -93G, 1151A, 655A in the hMLH1 gene could increase the PTC risk, with OR of 2.67 (95%CI: 1.16-6.53, P=0.011), compared with the haplotype of -93G, 1151T, 655A; (3) Compared to 3124A, 2835G haplotype in hMSH3 gene, the 3124G, 2835A haplotype could increase the PTC risk marginally, with OR of 3.08 (95%CI: 0.92-13.25). CONCLUSION: The 1151T/A polymorphism in hMLH1 was associated with PTC; both the haplotype of -93G, 1151A, 655A in hMLH1 and the 3124G, 2835A haplotype in hMSH3 were associated with PTC.

Are polymorphisms of N-acetyltransferase genes susceptible to primary liver cancer in Luoyang, China?

AIM: To identify whether the polymorphisms of the N-acetyltransferase (NAT) genes are susceptible to primary liver cancer (PLC) in Luoyang, a PLC low-incidence area of China. METHODS: The NAT1 and NAT2 genotypes of 96 PLC cases and 173 controls were determined by PCR-RFLP. Both interaction between NAT1 or NAT2 and environmental risk factors were analyzed based on case control study. RESULTS: Compared to the control group, the frequencies of alleles NAT1*3, NAT1*4, NAT1*10, NAT1*14B and alleles NAT2*4, NAT2*6, NAT2*7 in PLC group showed no statistically significant difference (chi(2) = 2.61 and 4.16, respectively, both P>0.05). The frequencies of NAT1 genotypes NAT1*3/*3, NAT1*3/*4, NAT1*3/*10, NAT1*3/*14B, NAT1*4/*4, NAT1*4/*10, NAT1*4/*14B, NAT1*10/*10, NAT1*10/*14B, and NAT2 genotypes NAT2*4/*4, NAT2*4/*6, NAT2*4/*7, NAT2*6/*6, NAT2*6/*7 and NAT2*7/*7 also had no statistically significant difference between the two groups (chi(2) = 11.86 and 2.94 respectively both, P>0.05). Neither the frequencies of rapid and slow NAT1 acetylators nor the frequencies of rapid and slow NAT2 acetylators were significantly different between the two groups (chi(2) = 0.598 and 0.44, respectively, both P>0.05). The interaction between NAT1*10 and occupational exposures was found significant with an odds ratio of 3.40 (chi(2) = 8.42, P = 0.004, OR 95%CI:1.03-11.22). But no interaction was found between NAT2 and any environmental risk factors. CONCLUSION: The polymorphisms of NAT1 and NAT2 are not susceptible to PLC in Luoyang. Allele NAT1*10 interacts with occupational exposures.

[Single nucleotide polymorphisms and point mutations of ataxia telangiectasia mutated gene in Chinese of Han ethnicity].

OBJECTIVE: To explore the single nucleotide polymorphisms (SNPs) and point mutations of ataxia telangiectasia mutated (ATM) gene in Chinese of Han ethnicity. METHODS: The target fragments of the exon 39, exon 61 and exon 63 of ATM gene were first amplified using PCR technique, then screened for the SNPs and point mutations using single strand conformation polymorphism (SSCP) technique, finally the representative bands were sequenced for the verification of the new single nucleotide polymorphisms and point mutations using the automatic DNA sequencing technique. RESULTS: Six new SNPs were found in the exon 39, intron 61 and intron 63 of ATM gene. They are respectively the A/T polymorphisms at nucleotide 5689 and 5691 in exon 39, the T/G polymorphisms at nucleotide +69 and +99, the A/G polymorphism at nucleotide +94 in intron 61, the G/C polymorphism at nucleotide +17 in intron 63. Five new point mutations were found in the exon 61, intron 62 and exon 63 of ATM gene. They are respectively the T/G transversion at nucleotide 8618 in exon 61, the T/G transversion at nucleotide -13 in intron 62, the T/G transversion at nucleotide 8793, the G/A transitions at nucleotide 8816 and 8848 in exon 63. The known three SNPs, the G/A polymorphism at nucleotide 5557 in exon 39, the T/C polymorphism at nucleotide +104 in intron 61 and the T/C polymorphism at nucleotide -55 in intron 62, were verified in Chinese of Han ethnicity. CONCLUSION: There are great differences in the SNPs of ATM gene between Chinese of Han ethnicity and Caucasian.

[Studies of genetic polymorphisms of ADH2 and ALDH2 among the Han population in Luoyang China].

In order to investigate genetic polymorphisms of ADH2 and ALDH2 among the Han population in Luoyang City,portions of exon 3 of ADH2 and exon 12 of ALDH gene were amplified by using polymerase chain reaction. The amplified products were electrophoresed on 10% undenatured vertical polyacrylamide gels and stained with argentine. Frequencies of ADH2*1 and ADH2*2 alleles are 42.86% and 57.14%. Frequencies of three genotypes of ADH2 are 22.86%,40.00% and 37.14%,respectively. Frequencies of ALDH2*1 and ALDH2*2 alleles are 85.24% and 14.76%. Genotype frequencies of ALDH2 loci are 71.43%,27.62% and 0.95%,respectively. Genetic polymorphisms of ADH2 and ALDH2 among the Han population in Luoyang City are different from those among Taiwanese and Shanghainese. Frequency of ALDH2*1/*1 in Luoyang people is higher than those in Shanghai and Taiwan. Therefore,there is a higher resistance to alcohol drinking in the Han population in Luoyang.

[Epidemiological investigation on endemic fluorosis along the Yellow River alluvial plain of Shandong province].

OBJECTIVE: To investigate the current prevalent status of endemic fluorosis in the floodplain area of the lower Yellow River in Shandong province. METHODS: According to "The National Technical Scheme for Endemic Disease Control in 2008", 16 counties were chosen to carry out the epidemiological survey of endemic fluorosis. Three villages were chosen in each county, to determine the fluoride content of drinking water and to check the dental fluorosis of children aged 8 to 12 year old, the skeletal fluorosis of adults over 16 years of age. Both children and adults were tested for urine fluoride. The content of fluoride in drinking water and urine was determined by F-ion selective electrode while dental fluorosis of children aged 8 to 12 years old was diagnosed by Dean's method and adults skeletal fluorosis by the National Standard for "Diagnosis of endemic skeletal fluorosis" (WS 192-2008). RESULTS: The investigation was taken place in 26 'improved-water-quality' villages in 16 counties, among which 19 villages had water fluoride content ≤ 1.00 mg/L and accounted for 73.08% (19/26), 7 villages had water fluoride content > 1.00 mg/L and accounted for 26.92% (7/26), with the highest water fluoride content as 3.73 mg/L. In 22 'yet to improve-water quality' villages in 16 counties, 5 villages had water fluoride content ≤ 1.00 mg/L (accounted for 22.73%), 17 villages had water fluoride content > 1.00 mg/L (accounted for 77.27%), with the highest water fluoride content as 3.38 mg/L. The overall rate of dental fluorosis among children aged 8 to 12 years old was 52.18% (1042/1997), with the index of dental fluorosis as 1.17 and the rate of dental damage as 8.01% (160/1997). The urinary fluoride values above 1.40 mg/L were found in 65.00% (845/1300) of children aged 8 to 12 years old, with the highest urinary fluoride concentrations as 18.53 mg/L. The rate of skeletal fluorosis by clinic and X-rays in adults older than 16 years old were 4.35% (1121/25 781) and 11.36% (5/44), respectively. The urinary fluoride values above 1.60 mg/L were found as 63.92% (606/948) in adults older than 16 years old, with the highest urinary fluoride concentrations as 21.35 mg/L. CONCLUSION: The status of endemic fluorosis had not been effectively controlled and the situation for endemic fluorosis control was still critical in the floodplain area of the lower Yellow River in Shandong province, suggesting that the preventive approaches on endemic fluorosis control should be strengthened.

[Somatic mutations of mitochondrial DNA in thyroid papillary carcinoma].

OBJECTIVE: To analyze the somatic mutations in the D-loop of mtDNA and further evaluate the possibility of mitochondrial genetic instability in thyroid papillary carcinoma. METHODS: Hypervariable regions ( HVR-I and HVR-II) in the D-loop of mtDNA from the specimen of 35 thyroid papillary cancers and matched lymphocytes were amplified by PCR, and then were sequenced. RESULTS: Comparing the sequences of tumors to those of matched lymphocytes and normal thyroid tissues, 5 somatic mutations in 2 patients (5.7%) were found. Two mutations were insertions of C in a poly-cytidine (nt303) microsatellite, and 3 at positions 73, 152 and 194 in HVR-II. In addition, of the 294 genetic variants detected, 292 were previously recorded polymorphisms, whereas 2 were new polymorphisms (nt324:C-->G, nt16092:T-->A). CONCLUSIONS: Mutations in the D-loop of mtDNA were found in thyroid papillary cancers, this mutation rate was lower than the reported rate of alteration in tumors of epithelial origin, and further work is required to elucidate the relationship between this mutations and the development of thyroid papillary carcinoma.

[A matched case-control study of papillary thyroid carcinoma].

OBJECTIVE: In order to explore the risk factors of the papillary thyroid carcinoma(PTC), a hospital-based matched case-control study was carried out in Shanghai. METHODS: Matched by gender, age (+/- 3 years old) and native place,205 pairs of cases and controls were recruited and studied. Database was established with Epi Info 6.0 software. Univariate and multivariate conditional logistic regression analysis were carried out with SPSS 11.5 software. RESULTS: Data from multivariate conditional logistic regression analysis showed that often drinking tea and having better economic living standard 20 years ago were protective factors of PTC, with ORs of 0.456 and 0.221 respectively. Personal history of CT examination, familial history of cancer and the mother's age was older than 22 years when the research subject was delivered, were risk factors of PTC, with ORs of 12.935, 7.027 and 3.729 respectively. Results data from multivariate analysis on female subjects showed that the history of CT examination, mother's age was older than 22 (when the subject was delivered) and the history of gynecological disease were the risk factors of PTC,with ORs of 107.453,29.246 and 59.521 respectively. Taking bean products frequently and having higher standard of living 20 years ago were the protective factors of PTC,with ORs of 0.025 and 0. 144 respectively. CONCLUSION: History of CT examination, familial history of cancer and the mother's age(older than 22 when the subject was delivered) were the risk factors of PTC. Frequent tea drinking habit and having higher standard of living 20 years ago were the protective factors of PTC. History of CT examination,mother's age (older than 22 when the subject was delivered) and the history of gynecological disease appeared the risk factors of PTC for women. Habit on frequent bean products taking and had higher standard of living 20 years ago were the protective factors of PTC to women.

[Genetic polymorphisms in X-ray repair cross-complementing gene 1 and susceptibility to papillary thyroid carcinoma].

OBJECTIVE: To study the association of polymorphisms in the X-ray repair cross-complementing gene 1 (XRCC1) and papillary thyroid carcinoma (PTC). METHODS: A hospital based, matched case-control study was carried out. The polymorphisms in XRCC1 for 105 pairs of cases with PTC and controls were identified by PCR-RFLP. RESULTS: The frequencies of Arg/Arg, Arg/Trp and Trp/Trp genotypes at XRCC1 Arg194Trp site were 47.6%, 49.5% and 2.9% among cases compared to 45.7%, 48.6% and 5.7% among controls. There was no statistically significant difference between the two groups (chi(2) = 1.07, P = 0.59). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln genotypes at XRCC1 Arg399Gln site were 46.7%, 41.9% and 11.4% among cases, while 54.2%, 42.9% and 2.9% among controls respectively. There was statistically significant difference between the two groups (chi(2) = 6.40, P = 0.04). Individuals with Gln/Gln genotype had a 3.65-fold increased risk of developing PTC compared to Arg/Arg genotype (OR = 4.65, 95% CI: 1.24 - 17.45). The multivariate conditional logistic regression analysis showed that the XRCC1 Arg399Gln polymorphism, negative life events and X-irradiation history were associated with PTC, with odds ratios of 2.71 (95% CI: 1.22 - 6.05), 5.34 (95% CI: 1.40 - 20.38) and 0.38 (95% CI: 0.12 - 0.72) respectively. However, XRCC1 Arg194Trp polymorphism, drinking tea, fruit and economic levels did not show statistically significant associations with PTC. CONCLUSION: The Gln/Gln genotype at XRCC1 Arg399Gln site and negative life events significantly increased while X-irradiation history decreased the risk of developing PTC.

Susceptibility to hepatocellular carcinoma associated with null genotypes of GSTM1 and GSTT1.

AIM:In order to study the association between the null genotypes of GSTM1 and GSTT1 and the genetic susceptibility to hepatocellular carcinoma (HCC).METHODS:The genotypes of GSTM1 and GSTT1 of 63 cases of HCC and 88 controls were detected with the multiple PCR technique.RESULTS:The frequency of GSTM1 null genotype was 57.1% among the cases, and 42.0% among the controls, the difference being statistically significant (X(2) = 3.35, P = 0.067), but X(2) value approaching the significance level. The odds ratio was 1.84 (95% CI = 0.91-3.37). The frequency of GSTT1 non-null genotype was 87.3% among the cases and 62.5% among the controls, the difference being statistically significant (X(2) = 11.42, P = 0.0007274). The odds ratio was 4.13 (95% CI = 1.64-10.70).According to the cross analysis, the GSTT1 non null genotype was more closely associated with HCC than GSTM1 null genotype, and these two factors play an approximate additive interaction in the occurrence of HCC.CONCLUSION:The persons with GSTM1 null genotype and GSTT1 non-null genotype have the increased risk to HCC.