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Inorganic arsenic (iAs) is a common carcinogen that exists in the environment. Liver, as the main target organ of arsenic metabolism, long-term exposure to iAs can ultimately lead to carcinogenesis through two stages: liver fibrosis and cirrhosis. Ferroptosis is a type of programmed cell death caused by the accumulation of iron dependent lipid peroxides that affects the normal function of mitochondria. It has been found that ferroptosis occurs during liver fibrosis. Liver fibrosis caused by iAs has been a global health problem for a long time, but so far there is no effective treatment. The discovery of ferroptosis provides a new way to solve this problem. Therefore, this article will review the research progress of the mechanism of liver injury caused by iAs and ferroptosis.
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Objective:Through the detection of iodine nutrition level and thyroid function of pregnant women in Xinjiang Uygur Autonomous Region (Xinjiang), to preliminary study the pregnant women's iodine nutrition level, thyroid function status and the relationship between the two and influencing factors.Methods:From March to June in 2020, stratified cluster random sampling method was adopted. Two counties (cities) in Southern and Northern Xinjiang were selected as survey sites, and about 100 pregnant women (a total of 412) were selected from each county (city) as survey subjects. Random urine samples and blood samples were collected to detect urinary iodine and serum thyroid function indicators [thyroid stimulating hormone (TSH), free triiodothyronine (FT 3), free thyroxine (FT 4), anti-thyroglobulin antibody (Tg-Ab) and anti-thyroid peroxidase antibody (TPO-Ab)]. Results:The median and interquartile range [ M ( Q1, Q3)] of pregnant women's urinary iodine was 228.4 (143.15, 327.95) μg/L. Serum FT 3, FT 4 and TSH levels [ M ( Q1, Q3)] were 4.22 (3.92, 4.61), 13.79 (12.63, 15.26) pmol/L and 1.82 (1.26, 2.52) mU/L, respectively. The overall positive rates of Tg-Ab and TPO-Ab were 5.61% (23/412) and 11.95% (49/412), respectively. The positive rates of Tg-Ab and TPO-Ab in Southern and Northern Xinjiang were 4.78% (10/209), 10.05% (21/209), 6.40% (13/203) and 13.79% (28/203), respectively. The positive rates of Tg-Ab and TPO-Ab in Northern Xinjiang were higher than those in Southern Xinjiang, but the difference was not statistically significant (χ 2 = 1.31, 2.17, P > 0.05). The positive rate of TPO-Ab in pregnant women was the influencing factor of abnormal thyroid function, and the odds ratio ( OR) [95% confidence interval ( CI)] was 3.22 (1.31 - 7.93). Conclusions:Pregnant women in Xinjiang are generally at an appropriate level of iodine, but the state of thyroid function still needs continuous attention. In addition, it is necessary to strengthen the thyroid function examination of pregnant women with positive thyroid autoantibodies to prevent and control the occurrence of abnormal thyroid function in pregnant women.
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Objective:To analyze DNA methylation sites related to fibrosis and autophagy in human hepatic stellate cells (LX-2 cells) induced by sodium arsenite (NaAsO 2), and to screen specific methylation genes related to fibrosis and autophagy. Methods:Genome-wide DNA detection was performed using Illumina Infinium Methylation EPIC BeadChips (850K methylation chip) to derive differential methylation sites in LX-2 cells (control group) and the fibrosis and autophagy models of LX-2 cells induced by NaAsO 2(low, medium and high dose groups: the final concentrations were 5, 10, 15 μmol/L NaAsO 2, respectively, after 48 h intervention). Gene ontology (GO) function enrichment analysis and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway enrichment analysis were used to explore gene function. Results:The model of cell fibrosis and autophagy was established successfully in high dose group. The results of 850K methylation chip detection showed that there were 25 817 significant different methylation sites between the high dose group and the control group, including 12 083 hypermethylation sites and 13 734 hypomethylation sites. GO function enrichment analysis showed that the molecular functions of differentially methylated genes mainly included protein binding, ion binding, catalytic activity, enzyme binding. KEGG signaling pathway enrichment analysis showed that the pathways involved in differentially methylated genes mainly included metabolic pathway, cancer pathway, phosphatidylinositol-3-kinase-protein kinase B (PI3K-Akt) signaling pathway, endocytosis, and mitogen activated protein kinase (MAPK) signaling pathway. In the promoter region, 11 and 29 differentially methylated genes related to fibrosis and autophagy were screened, respectively.Conclusions:A large number of differential methylation sites exist in the process of NaAsO 2 induced fibrosis and autophagy of LX-2 cells. Specific methylation genes related to fibrosis and autophagy are screened out.
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Objective:To learn about the arsenic status of drinking water in Urumqi City and evaluate its health risk, so as to provide scientific basis for the construction of water improvement projects in Urumqi City.Methods:From 2018 to 2020, 687 water samples were collected at monitoring sites in 7 districts and 1 county of Urumqi City for three consecutive years, and arsenic in drinking water was detected according to "Standard Examination Methods for Drinking Water - Nonmetal Parameters" (GB/T 5750.5-2006), and the arsenic in drinking water was evaluated according to "Standards for Drinking Water" (GB/T 5749-2006). The health risk of arsenic in drinking water in Urumqi City was evaluated by using the health risk assessment model recommended by United States Environmental Protection Agency (USEPA).Results:All of 687 water samples were centralized water supply, the arsenic compliance rates in dry season ( n = 342) and wet season ( n = 345), surface water ( n = 414) and underground water ( n = 273) were 100.0%. In dry season, the carcinogenic risk of arsenic via drinking water was 8.24 × 10 -6/a. In wet season, the carcinogenic risk of arsenic via drinking water was 3.30 × 10 -6/a. Conclusions:Remarkable achievements have been made in the construction of water improvement projects in Urumqi City, and the drinking water arsenic condition is good, the health risk of arsenic via drinking water is small. In the future, we should continue to strengthen the monitoring of drinking water quality, promote the construction of water improvement projects, further improve the drinking water sanitation, and put forward targeted prevention and control measures to ensure drinking water safety.
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Ambient air pollution has become a widespread global public health problem. As one of the main components of ambient air pollution, fine particulate matter (PM2.5), with its small diameter and large surface area, can carry a variety of toxic substances and enter the blood circulation directly through the blood-air barrier, damaging various tissues and organs of human body. Studies have shown that PM2.5 exposure during pregnancy can disrupt the mother's and child's thyroid function. Since the fetal thyroid gland does not begin to develop until around the sixth week of pregnancy, the fetal thyroid hormone is almost entirely dependent on the mother during early stages of pregnancy, and maternal thyroid hormone level play a crucial role in the growth and development of fetus. When a mother is exposed to PM2.5 during pregnancy, placenta, the "bridge" between mother and fetus, is also affected to some extent, including changes in placental iodine uptake and oxidative stress, inflammation, and DNA methylation in placental tissue. Exposure to PM2.5 during pregnancy also alters maternal thyroid hormone level and normal placental function, which can have a detrimental effect on pregnancy outcomes, such as preterm birth, low birth weight, and neurological abnormalities. This paper reviewed the effects of PM2.5 exposure during different trimesters on maternal and infant thyroid function, placental function, and pregnancy outcomes, aiming to provide more accurate protection of maternal and fetal health.
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Objective@#To examine the effect of chronic exposure to sodium arsenite on liver damages in rats. @*Methods@#Fifty-six healthy adult SD rats (28 males and 28 females) were randomly divided into 4 groups. Rats in the low-, medium- and high-dose groups were given sodium arsenite solutions at doses of 2, 10 and 50 mg/L for successive 24 weeks, while animals in the control group were given deionized water. The rat body and liver weights were measured and the liver coefficient was estimated. The urine arsenic level was detected using atomic fluorescence spectrometry, and hepatic tissue sections were stained with uranium acetate and lead citrate for morphological observations under an electron microscope. @*Results@#The body weights of both male and female rats appeared a tendency towards a rise with the duration of exposure to sodium arsenite (male rat: Wald χ2=3 610.621, P<0.001; female rat: Wald χ2=2 186.217, P<0.001, and there were no significant differences in the rat body weight 24 weeks post-exposure to sodium arsenite in each group, while there was an interaction between time and group (male rat: Wald χ2=15.874, P=0.001; Wald χ2=9.460, P=0.024). There were significant differences in the rat liver weight and liver coefficient in each group (male rat: F=18.964 and 29.968, both P<0.001; female rat: F=11.919 and 15.070, both P<0.001), with the lowest liver weight (10.17±1.15) g and liver coefficient (1.99±0.21)% measured in male rats in the high-dose group, and the highest liver weight (12.91±1.29) g and liver coefficient (4.10±0.56)% in female rats in the high-dose group. The median urine arsenic levels (interquartile range) were 25.60 (30.27), 146.56 (101.06), 1 034.68 (600.06) and 3 796.98 (19 966.89) μg/L in rats in the control, low-dose, medium-dose and high-dose groups, respectively (χ2=50.211, P<0.001), and the urine arsenic level was significantly higher in the medium- and high-dose groups than in the control group (both P<0.001). Hepatic edema was seen in rats in the low- and medium-dose groups, and hepatic edema, focal hepatic cell necrosis, hyperplasia of bile capillaries and peri-bile capillary endolysis were observed in rats in the high-dose group.@*Conclusions@#Chronic exposure to arsenic may cause morphological alterations of rat hepatic tissues, and the rat hepatic damage aggravates with the dose of exposure to arsenic.
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Iodine is widely present in nature and it is one of the essential trace elements for human body. Iodine affects normal growth, development and metabolism of human body by participating in the synthesis of thyroid hormones. Iodine deficiency affects nearly 1.9 billion people worldwide and it is one of the health problems of global concern. As a special group, pregnant women are the focus group of iodine deficiency. Iodine deficiency during pregnancy will not only lead to thyroid dysfunction, endemic cretinism, but also irreversibly affect fetal brain development, resulting in infant mental retardation and growth retardation. This article summarizes the research progress of iodine deficiency during pregnancy, focusing on the hazards and evaluation index of iodine deficiency during pregnancy, and provides reference for future research priorities of iodine deficiency during pregnancy.
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Objective:To investigate the effect of sodium arsenite (NaAsO 2) on autophagy protein microtubule-associated protein light chain 3 (LC3) and Beclin-1 in human hepatic stellate cells (LX-2 cells). Methods:LX-2 cells were cultured in vitro, and LX-2 cells were stably infected with red fluorescent protein-green fluorescent protein-microtubule-LC3 (RFP-GFP-LC3) lentivirus. Flow cytometry was used for screening and infection rate determination. Using a group design, different concentrations NaAsO 2 [μmol/L: 5.00 (infection + high arsenic dose group), 0.50 (infection + medium arsenic dose group), 0.05 (infection + low arsenic dose group), and 0.00 (infection group)] were incubated to stably infect LX-2 cells, and an in vitro liver fibrosis model was constructed, and a blank group was established. The effect of NaAsO 2 on the activity of LX-2 cells was detected by CCK-8 method. The mRNA and protein expression levels of LC3, Beclin-1 and α-smooth muscle actin (α-SMA) were detected by real-time fluorescent quantitative PCR and Western blotting. Results:After stable infection of LX-2 cells by RFP-GFP-LC3 lentivirus, the fluorescence rate of RFP and GFP was determined by flow cytometry, and the infection rate was about 70%. There was no significant difference in the fluorescence intensity of RFP and GFP observed under fluorescence microscope, and the infected cells were established successfully. After treatment with NaAsO 2 for 24, 48, 72 h, compared with the blank group, the cell viability of the infection group was not significantly different statistically ( P > 0.05), and the cell viability of other dose groups decreased ( P < 0.05). There were significant differences in the expression levels of LC3, Beclin-1, α-SMA mRNA and protein in blank, infection, infection + high arsenic dose, infection + medium arsenic dose, and infection + low arsenic dose groups ( F = 17.450, 11.084, 11.294, 11.745, 31.635, 12.130, P < 0.05). In infection, infection + high arsenic dose, and infection + low arsenic dose groups, the levels of LC3 mRNA (20.09 ± 6.50, 36.57 ± 9.68, 14.19 ± 6.17) were higher than that of the blank group (1.25 ± 0.21, P < 0.05), and the level of LC3 mRNA in infection + high arsenic dose group was higher than that of the infection group ( P < 0.05); in infection, infection + high arsenic dose, infection + medium arsenic dose, and infection + low arsenic dose groups, the levels of Beclin-1 mRNA (22.46 ± 0.66, 13.38 ± 2.27, 20.80 ± 6.95, 24.31 ± 7.09) were higher than that of the blank group (1.10 ± 0.53, P < 0.05); in infection + high arsenic dose, infection + medium arsenic dose, and infection + low arsenic dose groups, the levels of α-SMA mRNA (1.07 ± 0.27, 1.65 ± 0.17, 1.73 ± 0.26) were higher than that of the blank and infection groups (0.60 ± 0.11, 0.31 ± 0.09, P < 0.05). In infection, infection + medium arsenic dose, and infection + low arsenic dose groups, the LC3 protein expressions (0.20 ± 0.06, 0.15 ± 0.00, 0.16 ± 0.01) were significantly increased compared to that of the blank group (0.04 ± 0.01, P < 0.05); in infection + medium arsenic dose, and infection + low arsenic dose groups (0.83 ± 0.03, 1.20 ± 0.02), the Beclin-1 protein expressions were significantly increased compared to that of the blank group (0.25 ± 0.01, P < 0.05), and the Beclin-1 protein expression in infection + low arsenic dose group was increased compared to that of the infection group (0.53 ± 0.03, P < 0.05); in infection + medium arsenic dose, and infection + low arsenic dose groups (0.78 ± 0.10, 0.68 ± 0.06), the α-SMA protein expressions were significantly increased compared to that of the blank and infection groups (0.40 ± 0.07, 0.48 ± 0.04, P < 0.05). Conclusion:NaAsO 2 may affect the process of arsenic-induced liver fibrosis by promoting the autophagy level of LX-2 cells.
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Objective To investigate the prevalence and trend of dental fluorosis of 7-14 years old children in 134 Regiment,8 Division,Xinjiang Production and Construction Corps,and to evaluate the effectiveness of water improvement and fluoride control measures.Methods From 2010 to 2017,using cross-sectional survey,six water allocation places were selected from 134 Regiment,8 Division,Xinjiang Production and Construction Corps,and the fluoride content was determined.Children of 7-14 years old in 2 central primary schools were investigated,and dental fluorosis was examined.Taking 2017 as the benchmark,children born before water improvement were 11-14 years old,children born after water improvement were 7-10 years old.Water fluoride was detected via the ion-selective electrode method.Diagnosis of dental fluorosis was based on the standard of "Dental Fluorosis Diagnosis" (WS/T 208-2011).The detection rate of dental fluorosis was compared by x2 test,and rank sum test was used to compare the severity of the disease.Results A comprehensive water improvement and fluoride reduction project was completed in 134 Regiment,8 Division,Xinjiang Production and Construction Corps in 2007.The detection rate of dental fluorosis in children born before water improvement was 2.65 times higher than that of children born after water improvement [14.43％ (101/700) vs 5.44％ (33/607),X2 =28.567,P ＜ 0.01].The dental fluorosis index of children born before water improvement was also higher than that of children born after water improvement (0.33 vs 0.11).According to age standardization (based on 2017),there was a significant difference in the detection rate of dental fluorosis among children in different years (x2 =351.300,P ＜ 0.01).The detection rate of dental fluorosis in children decreased from 35.26％ in 2010 to 10.25％ in 2017.There was a statistically significant difference in the severity of dental fluorosis in children of different years (H =954.033,P ＜ 0.01).The dental fluorosis index of children decreased from 0.71 in 2010 to 0.23 in 2017,and the disease changed from extremely mild fluorosis epidemic to non-fluorosis epidemic.Conclusion After effective water improvement in 134 Regiment,8 Division,Xinjiang Production and Construction Corps,the prevalence of dental fluorosis in children in the disease affected areas has decreased significantly,the effect of defluoridation project is significant.
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Objective By analyzing the data of new syphilis cases from 2008 to 2014 in Bayinguoleng Mongolia Autonomous Prefecture (Bazhou for short) of Xinjiang to further provide reference basis for setting up control strategies.Methods Using the new syphilis data reported in Bazhou of Xinjiang,we constructed a dynamic model of transmission dynamics of syphilis,and the model was simulated and quantitatively analyzed.Results The syphilis dynamical model was introduced,the methods of setting the relevant parameters were given.It was found that the established model fitted well (MA PE =1.59％,RMSPE =0.68％),and the basic reproduction number of outbreak epidemic was estimated to be R0 =1.06 (95％ CI:1.01-1.15),it was predicted that the cumulative incidence of syphilis in Bazhou was 18 145 cases by 2024.In 2023,the cumulative number of cases was 16 465,and the number of new cases reached 1 680 in 2024.The infection rate,the number of core group partners and the treatment rate were main factors influencing the prevalence of syphilis after comparison of the sensitivity of the model parameters.Conclusion There is still an upward trend in the prevalence of syphilis infection in Bazhou of Xinjiang,and relevant departments should strengthen the prevention and control measures in high-risk groups,promote the use of condoms and other comprehensive intervention measures to control the prevalence of syphilis.
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Objective To observe the activation of rat hepatic stellate cells (HSC-T6) and the changes of methyltransferase (DNMT)1,DNMT3a mRNA expression with different doses of sodium arsenite stimulation.Methods HSC-T6 cells were exposed to a final concentration of 0 (control),5 (low dose),15 (medium dose) and 25 (high dose) μmol/L sodium arsenite in culture medium for 24,48 and 72 h,cells and cell culture supernatant were harvested.Enzyme-linked immunosorbent assay (ELISA) kit was used to measure fibrosis factors contents of type Ⅰ collagen (COL-1),type 11Ⅲ collagen (COL-3) and alpha smooth muscle actin (α-SMA) and quantitative real-time PCR was used to detect the expression levels of DNMT1 and DNMT3a mRNA.Results Different arsenic exposure time (24,48,72 h) had a significant effect on COL-1,COL-3 and α-SMA contents in HSC-T6 cells (F =249.574,328.493,3 157.436,all P ＜ 0.01);Different arsenic exposure content (low,medium,high dose groups) had a significant effect on COL-1,COL-3 and α-SMA contents in HSC-T6 cells (F =3 946.521,1 006.399,13 025.770,all P ＜ 0.01).After arsenic exposure for 24 and 48 h,the expression levels of DNMT1 mRNA in high dose group (4.33 ± 0.24,2.34 ± 0.43) were higher than those of control group (1.00 ± 0.00,1.00 ± 0.00,all P ＜ 0.05).At the same arsenic exposure levels (low,medium or high dose),the expression level of DNMT1 mRNA was declined with prolongation of sodium arsenite stimulation time (all P ＜ 0.05).After arsenic exposure for 48 and 72 h,the expression levels of DNMT3a mRNA in high dose group (2.23 ± 0.50,5.02 ± 0.23) were higher than those of control group (1.00 ± 0.00,1.00 ± 0.00,all P ＜ 0.05).The expression levels of DNMT3a mRNA in medium and high dose groups at 72 h (3.80 ± 0.14,5.02 ± 0.23) were higher than those of 24 h (3.03 ± 0.12,0.42 ± 0.15,all P ＜ 0.05).Conclusion HSC-T6 cells are obviously activated with pro-fibrotic effect;the expression levels of DNMT1 and DNMT3a mRNA are both up regulated in HSC-T6 cells after being exposed to sodium arsenite.
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Objective To study the mechanism of liver fibrosis in rats caused by chronic exposure through drinking water containing sodium arsenite,to identify the differential proteins via proteomics technique.Methods Totally 40 healthy 8-week-old male Sprague Dawley (SD) rats of specific pathogen free (SPF) grade were randomly divided into 4 groups,which were control group (deionized water),0.68,1.36 and 2.73 mg/kg sodium arsenite (iAs3+) treated groups,respectively.The rats were fed with iAs-treated drinking water freely for 24 consecutive weeks.Twenty-four hour urine sample,blood and liver samples were collected.Hepatic fibrosis indices,specifically,type Ⅲ precollagen (PC Ⅲ),type Ⅳ collagen (Ⅳ-C),hyaluronic acid (HA) and laminin (LN) were detected by enzymelinked immunoassay (ELISA).Based on the isobaric tags for relative and absolute quantitation (iTRAQ) reagent 8-plex experiment,combined with 2DLC-MS/MS,the proteins in rats liver tissue of the medium dose group and the high dose group were compared with the those of control groups.Results ①The serum HA contents in the C (control) group,the L (low dose) group,the M (medium dose) group and the H (high dose) group were (198.51 ± 16.64),(218.39 ± 34.98),(261.72 ± 30.56) and (297.31 ± 35.72) ng/L;the serum PCⅢ contents in C,L,M and H groups were (15.32 ± 2.15),(16.78 ± 2.64),(19.51 ± 0.85) and (21.42 ± 1.63) μg/L;the serum LN contents in C,L,M and H groups were (734.57 ± 86.00),(792.65 ± 94.15),(916.83 ± 84.40) and (1 008.09 ± 64.17) μg/L;the serum Ⅳ-C contents in C,L,M and H groups were (52.34 ± 14.65),(59.72 ± 12.84),(74.38 ± 4.83) and (78.46 ± 4.30) μ.g/L,respectively.The differences in serological indices of liver fibrosis between-groups were statistically significant (F =21.136,19.957,22.007,14.288,all P ＜ 0.05).In multiple comparison of serum HA,PCⅢ and LN,there were no statistical significant differences between L group and C group.M and H groups were higher than L group and C group,significant statistical difference was found between H group and M group (all P ＜ 0.05).②Combining iTRAQ with 2DLC-MS/MS,based on the confidence threshold of protein (unused protScore) ＞ 1.3 and at least 1 matched peptides within the 95％ confidence interval,2 948 proteins were identified.Totally 2 162 proteins were detected in three groups compared with Venn diagram,after removing significant different proteins in C group,687 up-regulated proteins and 548 down-regulated proteins were identified in M group;633 up-regulated proteins and 519 downregulated were found in H group;the differences of protein expression between M and H groups were not statistically significant (P ＞ 0.05).③Up-regulated proteins related to the metabolism including AS3MT,MAT,SHMT,CHDH,CTH,CSAD and BHMT in M and H groups;of the two kinds of proteins of MTR,METK1 was up-regulated and F1LRB8 was down-regulated.Proteins associated with GSH including Gsta1,Gsta4,Gsta5,Gstt1,Gstt2,Gstk1,Gstp1,Gstm1,Gstm2,Gstm3,Gss,Gpx1,Gpx4,Esd,Hagh,Glo1,Mgst1 and B6DYQ5 which were all up-regulated.Proteins associated with liver fibrosis were Hic-5,Gss and six kinds of Tpm,and six kinds of Tpm subunits including two kinds of Tpm1,three kinds of Tpm2 and one kind of Tpm3 which were all up-regulated.Conclusions There is liver accumulation of arsenic after chronic arsenic exposure and resulting in liver fibrosis and decline of liver function.Expressions of AS3MT,MTR,MAT,SHMT,BHMT,CHDH,CTH and CSAD are up-regulated;arsenic meta bolism methionine cycle,folic acid cycle and sulfur transfer pathways are closely related.GSH plays an important role in arsenic metabolism and liver fibrosis,Hic-5,GSS and TPM may be associated with the occurrence of liver fibrosis.
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Objective In order to understand the differentially expressed genes and explore the effects on mechanism of gene expression induced by arsenic trioxide. Methods The mRNA was isolated from human HepG2 cells treated with arsenic trioxide( 5?mol/L ) and DMSO, respectively, then cDNA was synthesized. After restriction enzyme Rsa Ⅰ digestion, small sizes cDNA were obtained. Then tester cDNA was subdivided into two portions and each was ligated with different cDNA adaptor. After tester cDNA was hybridized with driver cDNA twice and underwent nested polymerase chain reaction (PCR) twice, the DNA fragment was subcloned into T/A plasmid vectors to set up the subtractive cDNA library. Amplification of the library was carried out with E. coli strain JM109. The cDNA was sequenced and analyzed in GenBank with Blast search after colony PCR. Results The forward subtracted cDNA library from HepG2 cell line induced by arsenic trioxide was successfully constructed. The sequencing analysis showed that there were eight clones contained ferritin H(L) chain in the library. Conclusion Arsenic trioxide can induce the up expression of ferritin H(L) chain protein in HepG2 cells, indicated that the ferritin H(L) chain may play certain role in the mechanism of anti-arsenical cytotoxicity in liver.
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Objective To establish the method of high performance liquid chromatography and hydrid genesis atomic fluorescence spectroscopy(HPLC-HGAFS) about arsenic species in urine of rats treated with sodium arsenite.Methods The solution containing 15 mmol/L(NH4)2HPO4(pH=6.0)was used as the chromatographic eluant,the flow rate of which was 1.0 ml/min.The parameters of HPLC-HGAFS consisted of multiplier negative high voltage,hollow-cathode lamp's joint current and co-current,the flow rate of carrier gas,the flow rate of barrier shield gas,supporting liquid and reducing agent,which were 285 V,80 mA,36 mA,400 ml/min,600 ml/min,7%HCl and the mixed liquor of 1.5%KBH4 and 0.35% KOH respectively.Results The linear range of method was 20-100 ?g/L,and the linearity of regression equation of iAs3+,iAs5+,DMA was better.The lowest detection concentration of iAs3 +,iAs5 +,DMA in urine were 12.03,6.67 and 8.66 ?g/L respectively and all of the coefficient correlation were ≥0.98.The average recovery rates of DMA were 96.5%-103.4% and RSDs were 0.39%-1.26%.Conclusion The method has been proved accurate,sensitive and is applicable to the determination of arsenic species in urine.
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Objective To study cloning and the primary function of a new gene AsTP2 transactivated by arsenic trioxide. Methods Using suppression subtractive hybridization (SSH) technique, the mRNA was isolated from HepG2 cells treated with arsenic trioxide (5?mol/L) and 0.9 percent sodium chloride, respectively, then cDNA was synthesized. SSH method was employed to analyze the differentially expressed DNA sequences between the two groups. From the subtractive cDNA library of genes transactivated by arsenic trioxide, the coding sequence of a new gene was obtained by bioinformatics method, and amplified by the method of reverse transcription polymerase chain reaction (RT-PCR). Results The novel gene was named as AsTP2, which was logged in the GenBank with the accession number AY744366. AsTP2 of 1119 nucleotides (nt), coding a protein of 372 amino acid residues (aa). Conclusion A new gene has been recognized as the new target transactivated by arsenic trioxide. The results will give a new clue to explore the molecular carcinogenic mechanism of inorganic arsenic.
