ABSTRACT
Objective:To establish a method for automatic determination of iodine level in salt by arsenic-cerium catalytic spectrophotometry using an iodine element detector (hereinafter referred to as this method), and to provide reference for in-depth study of salt iodine detection technology.Methods:This method was used to determine the iodine level in salt, and the linear range, detection limit, precision, and accuracy (determination of salt iodine standard substance GBW10006y and GBW10007y, and addition recovery experiment) of this method were determined. The iodine level of 35 salt samples was determined by this method and redox titration method recommended by the national standard, and the results were compared.Results:This method had a good linear relationship within the range of 50 - 600 μg/L standard curve, the absolute value of the correlation coefficients was > 0.999 0, and the detection limit was 5.0 mg/kg. The relative standard deviation of iodine concentration in salt samples with low, medium and high iodine concentrations were all < 6.0%. The determination results of salt iodine standard substance GBW10006y and GBW10007y were within the given value ranges; three iodine concentrations (6.0, 10.0 and 30.0 mg/kg) were added to the salt samples, with an average recovery rate of 96.7% to 105.0%, and a total average recovery rate of 100.9%. The method comparison experiment showed that there was no statistically significant difference between the salt iodine determination results of this method and the redox titration method ( t = - 1.54, P = 0.132). Conclusion:This method has the advantages of high accuracy, good precision and wide linear range in determining salt iodine, and is suitable for the detection of large quantities of samples in salt iodine monitoring.
ABSTRACT
Objective To investigate the expression of transcription factor forkhead/winged helix transcription factor 3 (Foxp3),immune factor transforming growth factor-beta 1 (TGF-β1),and T-lymphocyte activation related factor interleukin-2 (IL-2) in peripheral blood of patients with coal-burning arsenic poisoning,and to analyze the effects of arsenic exposure on immune function.Methods A case-control study was conducted to investigate 149 cases [94 males and 55 females,(50.69 ± 6.14) years old] of arsenic poisoning in Yuzhang coalburning arsenic poisoning area,southwestern Guizhou Province,and the cases were diagnosed based on the "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015) and confirmed by clinical review.According to skin damage,the patients were divided into mild arsenic poisoning group (39 cases),moderate arsenic poisoning group (54 cases) and severe arsenic poisoning group (56 cases);and 41 cases [12 males and 29 females,(45.76 ± 7.88) years old] of non-arsenic exposed residents from 12 km of Yuzhang coal-burning area were selected as control group.Morning urine and peripheral blood samples were collected with informed consent.Urine arsenic content was measured by inductively coupled plasma mass spectrometry (ICP-MS).Urine arsenic was corrected by creatinine (Cr).Detection of regulatory T cell (Treg)-specific transcription factor Foxp3 gene expression in human peripheral blood was done by real-time fluorescence quantitative PCR,and the levels of Treg-related immune factor TGF-β1 and IL-2 in serum were detected by enzyme linked immunosorbent assay (ELISA).Results The urinary arsenic contents [median (quartile):29.13 (19.75-54.50),31.81 (17.52-53.31),30.51 (18.35-45.76) μg/g Cr] in each arsenic poisoning group were higher than that in the control group [21.62 (17.65-28.44) μg/g Cr,P ＜ 0.05].The expression levels of Foxp3 mRNA in peripheral blood of each arsenic poisoning group [median (quartile):0.58 (0.17-1.27),0.32 (0.17-0.61),0.33 (0.13-0.62)] were significantly lower than that in the control group [0.87 (0.64-1.50),P ＜ 0.05];compared with mild arsenic poisoning group,the expression of Foxp3 mRNA in peripheral blood of moderate and severe arsenic poisoning groups decreased (P ＜ 0.05).The contents of serum TGF-β1 [(13.14 ± 5.19),(12.85 ± 5.51),(12.78 ± 4.95) μg/L] in each arsenic poisoning group were significantly higher than that in the control group [(3.90 ± 1.53) μg/L,P ＜ 0.05].The levels of IL-2 in serum of each arsenic poisoning group [(9.85 ± 5.38),(11.64 ± 6.40),(12.27 ± 6.19) ng/L] were lower than that in the control group [(34.30 ± 4.84) ng/L,P ＜ 0.05];the serum level of IL-2 in severe arsenic poisoning group was higher than that in mild arsenic poisoning group (P ＜ 0.05).Conclusions Arsenic exposure can cause abnormal changes of Treg-specific transcription factor Foxp3 and related immune factors TGF-β1 and IL-2 in peripheral blood of patients.It is suggested that Treg dysfunction may be related to arsenic poisoning.
ABSTRACT
Objective To observe the change of T helper 17 (Th17),regulatory T cell (Treg) as a percentage of lymphocytes and the Th17/Treg ratio in peripheral blood of patients with coal-burning-borne arsenic poisoning,and to explore the role of Th17 cells and Treg cells balance in arsenic-induced immune injury.Methods A case-control study was conducted to investigate 149 cases of arsenic poisoning in Yuzhang arsenic poisoning area in the southwestern Gnizhou Province,and the age was (50.69 ± 6.14) years old,including 94 males and 55 females.The diagnosis was based on the "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015),and the cases were divided into mild arsenic poisoning group (39 cases),moderate arsenic poisoning group (54 cases) and severe arsenic poisoning group (56 cases);forty--one residents of non-arsenic exposed villages about 12 km away from the diseased area were collected as control group,the age was (45.76 ± 7.88) years old,including 12 males and 29 females.Hair samples and peripheral blood were collected from the subjects.The content of hair arsenic was detected by inductively coupled plasma mass spectrometry (ICP-MS).The percentages of Th17 cells and Treg cells in peripheral blood lymphocytes were detected by flow cytometry,and changes in the ratio of Th17/Treg in each group were analyzed.Results The hair arsenic contents in control,mild,moderate,and severe arsenic poisoning groups [median (quartile)] were 0.12 (0.08-0.18),0.20 (0.16-0.33),0.25 (0.18-0.41),0.28 (0.21-0.50) μg/g,and the differences were statistically significant between groups (H =52.22,P ＜ 0.01),and the hair arsenic content in each arsenic poisoning group was higher than that of the control group (P ＜ 0.05).The percentages of Th17 cells in peripheral blood lymphocytes of moderate and severe arsenic poisoning groups [(0.42 ± 0.21)％,(0.41 ± 0.23)％] were higher than that of the control group [(0.29 ± 0.16)％,P ＜ 0.05].The percentages of Treg cells in peripheral blood lymphocytes of mild,moderate and severe arsenic poisoning groups [(0.37 ± 0.18)％,(0.31 ± 0.19)％,(0.27 ± 0.18)％] were lower than that of the control group [(0.71 ± 0.20)％,P ＜ 0.05];with respect to the mild arsenic poisoning group,the percentage of Treg cells in severe arsenic poisoning group was reduced (P ＜ 0.05).The ratios of Th17/Treg in mild,moderate and severe arsenic poisoning groups (1.17 ± 0.63,1.56 ± 0.69,1.83 ± 0.85) were higher than that of the control group (0.43 ± 0.22,P ＜ 0.05);compared with mild arsenic poisoning group,the ratio of Th17/Treg in severe arsenic poisoning group was elevated (P ＜ 0.05).Correlation analysis showed that the hair arsenic content was positively correlated with the percentage of Th17 cells in peripheral blood lymphocytes and the ratio of Th17/Treg (r =0.323,0.608,P ＜ 0.05),and negatively correlated with the percentage of Treg cells in peripheral blood lymphocytes (r =-0.486,P ＜ 0.05).Conclusion Coal-burning-borne arsenic poisoning can cause the proportion of Th17 cells in the peripheral blood of patients to increase in lymphocytes,and the proportion of Treg cells in lymphocytes to decrease,which in turn changes the balance of Th17/Treg,resulting in weakened immune tolerance and disorder the regulation of inflammatory response,thus participates in the occurrence and development of arsenic-induced immune damage.