The regulation mechanism of protein kinase Cδ on arsenic liver injury caused by coal-burning / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of mRNA transcriptional and protein expressions of protein kinase Cδ (PKCδ) on the development of arsenic liver injury caused by coal-burning.</p><p><b>METHODS</b>Population study:133 arsenic exposures were selected as arsenic exposure groups including the ward non-patient group (25 cases) , no obvious hepatopathy group (38 cases) , mild (43 cases) and moderate to severe hepatopathy group (27 cases) from the area with endemic arsenism in Guizhou province. Another 34 healthy residents were selected as the control group in non-arsenic pollution village. The urine and peripheral blood were collected from the subjects. The arsenic contents in urine and mRNA expressions of PKCδ in peripheral blood were detected. Animal experiment study:thirty wistar rats were randomly by random number table divided into control group, drinking water arsenic poisoning group and coal-burning arsenic poisoning group (i.e., low, medium and high arsenic contaminated grain group) by random number table method, including 6 rats in each group. The control group was fed normally for 3 months, drinking water arsenic poisoning group and coal-burning arsenic poisoning groups were fed respectively with 10 mg/kg As2O3 solution and different concentrations (25, 50 and 100 mg/kg) of arsenic-containing feed which was persisted 3 months. The arsenic contents in urine, mRNA expression levels of PKCδ in peripheral blood and liver tissue and the protein expression levels of phosphorylated protein kinase Cδ(pPKCδ) in liver tissue were detected.</p><p><b>RESULTS</b>The median(quartile) of arsenic contents in urine were 25.58 (18.62-40.73), 56.66 (38.93-76.77), 64.90 (39.55- 98.37) and 75.47 (41.30-109.70) µg/g Cr respectively for the non-patient group, no obvious hepatopathy group, mild and moderate to severe hepatopathy group. The levels were higher than that in the control group (23.34 (17.84-37.45) µg/g Cr) (P < 0.05), except for the ward non-patient group. The arsenic contents in rat urine were 2223.61 (472.98-3976.73), 701.16 (194.01-1300.27), 1060.94 (246.33-2585.47) and 3101.11 (1919.97-5407.07) µg/g Cr, respectively for the drinking water arsenic poisoning group, the low, medium and high dosage arsenic grain contamination groups, all higher than that in the control group (94.32 (22.65-195.25) µg/g Cr) (P < 0.05) . The protein expressions of pPKCδ in liver tissue were 324.83 ± 25.06, 278.50 ± 30.57, 308.83 ± 34.67 and 326.33 ± 35.09, which were significantly higher than that in the control group (240.17 ± 28.07) (P < 0.05) . The protein expression levels of pPKCδ in liver cell membrane were 0.49 ± 0.06,0.33 ± 0.05,0.37 ± 0.06 and 0.50 ± 0.08, which were significantly higher than that in the control group (0.28 ± 0.04) (P < 0.05) . The protein expression levels of pPKCδ in liver cell cytoplasm were 0.38 ± 0.06,0.31 ± 0.05, 0.35 ± 0.05 and 0.36 ± 0.05, which were significantly higher than that in the control group (0.24 ± 0.05) (P < 0.05).</p><p><b>CONCLUSION</b>The arsenic may regulate protein expressions of pPKCδ and induce its membrane translocation, and cause the development of arsenic liver injury caused by coal-burning.</p>

Regulating effects of Rosa roxburghii tratt preparation on immune function in arseniasis patients caused by coal burning / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the influence of rosa roxburghii tratt preparation on immune function of arseniasis patients caused by burning coal.</p><p><b>METHODS</b>According to the diagnosis standard for endemic arseniasis(WS/T 211-2001), 62 cases of arseniasis patients who resided in endemic arseniasis area in Guizhou province were selected and divided stratified randomly into two groups: rosa roxburghii tratt juice treatment group and superoxide dismutase(SOD)-enriched rosa roxburghii tratt juice treatment group, with 31 patients in each group.Each patient took 120 ml/d rosa roxburghii tratt preparation or SOD-enriched rosa roxburghii tratt orally for one month. Another 30 healthy residents from a neighbour township 12 km away where arsenic was not prevalent were selected as controls. A 2 ml blood and 50 ml urine samples were collected from individuals and the urine arsenic contents, peripheral blood T-lymphocyte subsets (CD3(+), CD4(+), CD8(+) T cell), serum immunoglobulin (IgG, IgM, IgA) and complement (C3, C4) were detected. The differences between more than two groups on above indicators were compared. The correlations between urinary arsenic and immune parameters were analyzed.</p><p><b>RESULTS</b>Among the rosa roxburghii tratt juice group, SOD-enriched rosa roxburghii tratt juice before intervention group and the control group, the levels of urine arsenic were (76.55 ± 23.02) , (72.60 ± 25.91) and (26.33 ± 11.30) µg/g Cr respectively and IgG were (11.31 ± 1.68), (11.35 ± 1.94) and (9.23 ± 1.75) g/L respectively. The differences were statistically significant(F values were 82.01, 13.82, both P values < 0.05). After intervention with rosa roxburghii tratt preparation, the levels of urine arsenic were (53.21 ± 16.51) and (51.72 ± 17.70)µg/g Cr, both decreased than before intervention (t values were 5.80 and 3.78, both P values < 0.05). The levels of CD3(+) were (44.47 ± 7.14)%, (43.44 ± 6.61)% and (70.78 ± 5.26)%, CD4(+) were (29.87 ± 5.67)%, (29.42 ± 5.87)% and (46.08 ± 5.87)%, CD4(+)/CD8(+) were(1.25 ± 0.42), (1.22 ± 0.39) and (1.79 ± 0.26) and C4 were (0.13 ± 0.08), (0.13 ± 0.09) and (0.20 ± 0.11) g/L respectively among the two treatment group before intervention and the control group. The differences were significant (F values were 178.04, 76.71, 23.13 and 5.26, all P values < 0.05). After intervention, the levels of CD3(+) were (59.73 ± 7.38)% and (66.31 ± 7.57)%, CD4(+) were (34.00 ± 7.97)% and (39.11 ± 5.81)%, CD4(+)/CD8(+) were (1.41 ± 0.37) and(1.58 ± 0.26), all increased than before intervention(t values were 12.47, 25.18, 5.41, 10.47, 3.22 and 5.05, all P values < 0.05). The levels of urine arsenic and CD3(+), CD4(+), CD4(+)/CD8(+), C4 were inversely correlated correlation, while positive correlation existed between the level of urine arsenic and IgG(r values were -0.68, -0.56, -0.51, -0.43 and 0.36, all P values < 0.01).</p><p><b>CONCLUSIONS</b>The level of urinary arsenic level is closely related to immune function suppression in arseniasis patients caused by burning coal, rosa roxburghii tratt preparation can effectively improve immune function of arseniasis patients.</p>

The mRNA expression of mitogen-activated protein kinase signal pathway related genes in the blood of arseniasis patients caused by burning coal / 中华预防医学杂志

<p><b>OBJECTIVE</b>To detect the mRNA expression of ERK1, ERK2, JNK1 and P38 gene in mitogen-activated protein kinase(MAPK) path way in the arseniasis patients caused by burning coal.</p><p><b>METHODS</b>70 arseniasis patients caused by burning coal at Jiaole village XingRen county in December 2006 were selected as case group, and another 30 villagers with similar living habits, matched gender and age, healthy physical condition without history of burning high arsenic coal were selected as control group from 12 km nearby the same village.Silver diethyl dithiocarbamate method (Ag-DDC) was taken to detect the arsenic contents in the environmental media, food, and arsenic level in the urine and hair of arseniasis patients.On the principle of informed consent, the peripheral blood was collected from the patients. The total RNA was extracted with Trizol method and cDNA was reversed from it. The mRNA expression of ERK1, ERK2, JNK1 and P38 gene in MAPK path way were tested by real-time fluorescent quantitative PCR (QT-PCR).</p><p><b>RESULTS</b>A total of 70 cases of arseniasis patients (31 cases of mild, 25 cases of moderate and 14 cases of severe) and 30 cases of control were chosen. The median (quartile) of arsenic contents in the indoor air, outdoor air, coal, chili and corn were 0.079 (0.053-0.117) mg/m(3) ,0.007 (0.002-0.015) mg/m(3) , 93.010 (39.460-211.740) mg/kg, 3.460(0.550-16.760) mg/kg and 1.500(0.300-4.140) mg/kg respectively. They were above the national health standards. The median (quartile) of arsenic contents in the soil, rice and drinking water were separately 12.130(4.230-24.820) mg/kg, 0.650(0.300-0.980) mg/kg and 0.043(0.012-0.089)mg/kg, which were within the national health standards. Compared with the control group ((26.97 ± 9.71)µg/g Cr), arsenic level in the patients' urine ((71.48 ± 22.74)µg/g Cr) increased significantly, the differences were significant (F = 90.38, P < 0.01). Compared with the control group ((1.58 ± 1.07)µg/g), arsenic level in the patients' hair ((4.45 ± 2.78) µg/g) increased significantly, the differences were significant (F = 48.22, P < 0.01). The relative expression amount of the median(quartile) for ERK2, JNK1 mRNA were 0.0667 (0.0378-0.1371) and 0.0013 (0.0009-0.0025), respectively. Compared with the control group 0.1744 (0.1009-0.1985) and 0.0022 (0.0017-0.0030) , only the decreases of ERK2, JNK1 mRNA expression was significant (χ(2) = 15.10, 14.25, P < 0.01), and no significance in the other index. ERK2 mRNA relative expression for mild, medium and severe groups were separately 0.0818 (0.0408-0.1509) ,0.0582 (0.0154-0.1699) and 0.0588 (0.0399-0.1034) . Compared with the control group (0.1744 (0.1099-0.1985) ), there was significant difference (Z = -2.89, -3.19, -2.67, P < 0.01). JNK1 mRNA relative expression were 0.0012 (0.0007-0.001 57), 0.0019 (0.0011-0.0035), 0.0013 (0.0010-0.0026), respectively. Compared with the control group (0.0022 (0.0017-0.0030) ), significances were found in the mild groups (Z = -3.72, P < 0.01).</p><p><b>CONCLUSIONS</b>Arsenic could induce the changes of ERK2 and JNK1mRNA expression in the MAPK path way in arseniasis patients.It suggests that the MAPK signaling pathway take part in the occurrence and development process of arseniasis caused by burning coal.</p>

Relationship of DNA methylation, mRNA transcription and protein expression of glutathione-S-transferases-P1 gene and coal-pollution-borne endemic arsenism / 中国地方病学杂志

Objective To investigate DNA methylation in the promoter region,mRNA transcription and protein expression of glutathione-S-transferases-P1 (GSTP1) gene and their relation with arsenism.Methods In endemic coal-pollution-borne arsenism area,Jiaole village of Xinren county,Guizhou province,according to the diagnostic criteria of endemic arsenism(WS/T 211-2001),123 cases with endemic arsenism were selected and divided into three groups (mild arsenism group:42 cases,moderate arsenism group:41 cases and severe arsenism group:40 cases).Forty seven residents were selected as controls in a village about 12 km away from the endemic arsenism area.With the informed consent principle,peripheral blood of all respondents was collected in order to analyze DNA methylation and check mRNA.DNA methylation of GSTP1 gene promoter region in peripheral blood was assayed by PCR,and GSTP1 mRNA expression was assayed using real-time quantitative PCR.In addition,other cutaneous specimens originated from 53 cases with arsenism that accepted surgical treatment voluntarily were taken.Of these specimens,general pathological changes were 28 cases,precancerous 20 cases and cancerous 5 cases.Skin tissues of 15 cases of non-tumor surgery patients without abnormal pathological changes were as control group.GSTP1 protein expression in the skin tissue was detected using immunohistochemistry (IHC).Results Among different groups of arsenic poisoning,the positive rate of DNA methylation of GSTP1 gene was 28.57％(12/42) in the mild group,57.10％ (23/41) in the moderate group and 65.00％ (26/40) in the severe group.Compared with the control group (6.38％,3/47),the difference was statistically significant (x2 =7.792,26.000,33.412,all P ＜ 0.01).Among different groups of arsenic poisoning diagnosed by dermapathology,the positive rate of DNA methylation of GSTP1 gene was 21.43％(6/28) in the general pathological change group,50.00％(10/20) in the precancerous group and 80.00％(4/5) in the cancerous group.Compared with the control group(6.67％,1/15),the difference was statistically significant (x2 =3.562,7.468,10.756,all P ＜ 0.05).It showed that the positive rate of DNA methylation of GSTP1 gene increased with aggravation of the disease and dermatic lesion of arsenism (tendency x2 =38.239,x2 =13.659,all P ＜ 0.01).Compared with the control group(0.184 26),the expressions of GSTP1 mRNA in peripheral blood in moderate (0.087 77) and severe arsenic poisoning groups (0.056 93) were significantly reduced(all P ＜0.01),and that of severe group was significantly lower than that of the moderate group (P ＜ 0.01) ; compared with the control group(0.338 45) and the general lesion group(0.276 74),GSTP1 mRNA expression was significantly reduced in precancerous lesion group(0.104 81) and cancerous group(0.043 70),in which the cancerous group was significantly lower than that of the precancerous lesions.The difference of skin tissue GSTP1 protein expression rate between groups was statistically significant (x2 =20.948,P ＜ 0.05),in which the difference between the precancerous lesion group(65.00％,13/20),the cancer group (40.00％,2/5) and the control group(100.00％,15/15)was statistically significant (x2 =12.183,11.778,P ＜ 0.01).Spearman correlation analysis showed that the degree of skin lesion and the level of GSTP1 protein expression was negatively correlated (r =-0.520,P ＜ 0.05).Groups were divided according to DNA methylation of GSTP1 gene,and the mRNA and protein expression of GSTP1 in methylation group(0.038 40,57.14％) was significantly lower compared with that of unmethylated group(0.187 07,95.74％; Z =9.032,x2 =23.134,all P ＜ 0.01).Conclusions Arsenism may lead to DNA methylation of human GSTP1 gene promoter region,thereby inhibiting expression of mRNA and protein.GSTP1 gene plays an important role in arsenism or carcinogenic process.

Expression of P14ARF, MDM2 and mutant type P53 in skin tissue of coal-burning-type of endemic arseniasis patients / 中国地方病学杂志

Objective To determine the protein expression of P14ARF,MDM2 and mutant type P53 (P53mt) in skin specimens of coal-burning-type of endemic arseniasis patients and to reveal the molecular mechanism of the disease.Methods Sixty skin specimens from 60 endemic arseniasis patients including 35 of skin lesions patients,19 of precancerous lesion and 6 of skin cancer and 9 normal skin specimens from non-cancer patients were studied.Expression of P14~,MDM2 and P53mt was evaluated by immunohistochemistry using corresponding monoclonal antibodies.Results There was significant difference in the positive rates of P14ARF,MDM2 and P53mt among the 4 groups(x2 =9.39,6.21,20.64,all P ＜ 0.05).The positive rates of P14ARF in precancerous lesion and skin cancer specimens were 46.1％ (6/19) and 33.3％ (2/6),respectively,which were significantly lower than that of the normal skin specimens [88.9％(8/9),all P ＜ 0.05].Decreased expression of P14ARF was correlated with the development of dermopathy (P ＜ 0.05).The positive rates of MDM2 and P53mt in skin lesions,precancerous lesion and skin cancer specimens were 54.2％ ( 19/35 ),63.2％ (10/19),66.7％ (4/6) and 25.7％(9/35),73.7％(14/19),83.3％(5/6),respectively,which were significantly higher than those of the control (0,0,all P＜ 0.05).The expression of MDM2 and P53mt increased with the development of dermopathy(all P ＜ 0.05).Conclusions P53mt protein in skin tissue of coal-burning-type of endemic arseniasis patients is over expressed.Abnormal expression of P14ARF and MDM2 may be one of the reasons lead to abnormal cell cycle control disorders and may play a role in the development of endemic arseniasis.

Relationship between the genetic polymorphisms in nucleotide excision repair genes of ERCC1, XPD, XPC and the arsenism caused by coal-burning / 中国地方病学杂志

Objective To investigate the relationship between genetic polymorphisms in excision repair cross-complementing 1 (ERCC 1 ),xeroderma pigmentosum group D (XPD),xeroderma pigmentosum group C (XPC) and the risk of arsenism caused by coal-burning.Methods Two hundred and twenty-nine patients with arsenism in the endemic area of Jiaole village Xingren county Guizhou province were selected into experimental group.One hundred and ninety-eight inhabitants who had similar living habits but did no burning coal with high arsenic in Dagnoduo village were selected into control group.Two milliliters vein blood samples were taken and analyzed with polymerase chain reaction-restriction frgment length polymorphism technique (PCR-RFLP) to measure the gene polymorphisms of ERCC1 C8092A,XPD Lys751Gln,XPD Asp312Asn,XPD Arg156Arg,and XPC P(AT +/-).Relationship between genotype and the risk of arsenism was also analyzed.Results The frequency of ERCC1 8092CA/AA geno-type in case group [ CA:29.78％ (67/225),AA:10.67％ (24/225) ] was significantly higher than that of control group[CA:23.08％(45/195),AA:5.13％(10/195),x2 =8.116,P ＜ 0.05].The frequency difference of other gene polymorphisms between case and control group was not statistically significant,respectively (x2 =5.649,4.394,0.865,1.490,all P ＞ 0.05).There were 1.780(95％CI:1.174 - 2.698),1.681(95％CI:1.081 - 2.615),and 1.790(95％CI:1.014 - 3.158)-fold increase in risk of arsenism for individuals carrying ERCC1 8092CA + AA,XPD Lys751Gln + Gln751Gln,and XPD Asp312Asn + Asn312Asn genotypes compared respectively with individuals canying ERCC1 8092CC,XPD Lys751Lys,and XPD Asp312Asp(all P ＜ 0.05).The sufferers only with XPD Arg156Arg or XPC P(AT +/-) didn't have higher risk of arsenism(all P ＞ 0.05).Conclusion The results of this study suggest that the gene polymorphisms of ERCC1 C8092A,XPD Lys751Gln,and Asp312Asn are related to the arsenism caused by coal-burning.

Transcription and expression of excision repair cross complementing 1 in endemic arsenism caused by coal-burning / 中国地方病学杂志

Objective To study the transcription and expression of excision repair cross complementing 1(ERCC1) in the peripheral blood and the skin tissue in coal-burning borne endemic arsenism, and to explore the role of arsenism in its pathogenic or carcinogenesis mechanism. Methods According to "Endemic arsenism diagnostic criteria" (WS/T 211-2001), 110 arsenism patients were chosen as case group in Xingren county,Guizhou province and they were divided into 3 groups according to their hnir arsenic: ＜ 2(31 cases),2 ～＜ 4(31 cases),≥4 mg/kg(48 cases), respectively. Another 36 healthy residents about 13 km away from the endemic area were chosen as healthy control group. Under the principle of informed consent, hair samples were collected for arsenic analysis by Ag-DDC and blood samples were collected to determine mRNA expression levels of ERCCI by real-time fluorescence quantitative PCR. At the same time, skin tissue samples were collected from the voluntary surgical treatment of 62 patients with endemic arsenism as case group which were divided into 3 groups according to their hair arsenic: ＜ 2(16 cases), 2 ～＜ 4(20 cases) and ≥4 mg/kg(26 cases), respectively, and these patients were also divided into general pathological changes (32 cases), precancerous (19 cases) and cancerous groups( 11cases), respectively, according to their skin pathologic diagnosis of skin lesions. Another 13 cases pathologically normal without skin cancer surgery from a certain hospital were chosen as control group. Skin samples were collected to detect the ERCC1 protein by immunohistochemical method. Results The mRNA levels of ERCC1 were 0.7156(0.2158 ～ 1.2405),0.5772(0.0843 ～ 1.1234) and 0.5490(0.1895 ～ 0.8431 ), respectively, among ＜ 2, 2 ～＜ 4and ≥4 mg/kg groups, which were lower than the mRNA levels of ERCC1 in the control group[1.5128(1.0000 ～2.1295)], and the difference was statistically significant(all P ＜ 0.05). The expression rate of ERCC1 protein were 87.5%, 80.0% and 77.0%, respectively, among ＜ 2, 2 ～＜ 4 and ≥4 mg/kg groups. The expression rate of ERCC1 protein in 2 ～＜ 4 and ≥4 mg/kg groups were lower than the rate in the control group(100.0%), and the difference was statistically significant (all P ＜ 0.05). The expression rate of ERCC1 protein were 84.4%, 79.0%and 72.8%, respectively, among general pathological changes, precancerous and cancerous groups compared with the control group( 100.0% ), and the difference was statistically significant(all P ＜ 0.05). Conclusions Arsenic from coal-burning can lead to abnormal ERCC1 gene transcription and protein expression, which may inhibit DNA repair through influencing the removal of damaged DNA and promoting the incidence of arsenism development and even skin carcinogenesis.

Relationship between the methylation and mutation of p53 gene and endemic arsenism caused by coal-burning / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the influence of arsenic pollution caused by coal-burning on methylation (promoter and exon 5) and mutation (exon 5) of human p53 gene, and to analyze the relationship between methylation, mutation and arsenism.</p><p><b>METHODS</b>According to the diagnostic criteria of endemic arsenism, 112 patients with arsenism (including 38 mild cases, 43 moderate cases and 31 severe cases) were selected in the areas with endemic arsenism from Xingren, Guizhou province. Among the subjects, 43 cases were diagnosed by dermatopathological methods, and they were divided into non-cancerous group (24 cases) and cancerous group (19 cases). 90 controls were selected from the non-arsenic polluted areas. Under the principle of informed consent, blood samples were collected from individuals. The methylation of p53 gene in promoter region and exon 5 were detected by extinction enzyme-PCR, the mutation of p53 gene (exon 5) was detected by PCR-SSCP, PCR products cloning and sequencing technology.</p><p><b>RESULTS</b>The positive rates of methylation of p53 gene in promoter region were 13.16% (5/38), 27.91% (12/43) and 45.16% (14/31) respectively among mild, moderate and severe arsenism group, which were obviously higher than the rates in the control group (1.11% (1/90), χ² values were 8.679, 23.690, 41.199, respectively, both P values < 0.017). The positive rates of methylation of p53 gene were 25.00% (6/24) and 63.16% (12/19) in non-cancerous and cancerous group respectively, which were obviously higher than those in the control group (1.11% (1/90), χ² values were 18.762, 57.497, respectively, both P values < 0.025). The positive rates of methylation of p53 gene (exon 5) were 55.26% (21/38), 51.16% (22/43) and 48.39% (15/31) respectively among mild, moderate and severe arsenism group, which were obviously lower than the rates in the control group (88.88% (80/90), χ² values were 18.151, 23.168, 22.420, respectively, both P values < 0.017). The positive rates of methylation of p53 gene (exon 5) were 54.17% (13/24) and 42.11% (8/19) in non-cancerous and cancerous group respectively, which were obviously lower than those in the control group (88.88% (80/90), χ² values were 15.201, 22.075, respectively, both P values < 0.025). The mutation rates of p53 gene (exon 5) were respectively 5.26% (2/38), 16.28% (7/43) and 25.81% (8/31) among mild, moderate and severe arsenism group; while the results in moderate and severe arsenism group were obviously higher than in the control group (0.00%, χ² values were 15.465, 24.870, respectively, both P values < 0.017). The positive rate of mutation of p53 gene (exon 5) were respectively 16.67% (4/24) and 31.58% (6/19) in non-cancerous and cancerous group, which were obviously higher than it in the control group (0.00%, χ² values were 15.545, 30.077, both P values < 0.025). The hypermethylation of p53 gene in promoter region was related with the mutation of p53 gene (exon 5) (coefficient of association was 0.294, P value < 0.05); and the hypomethylation of p53 gene (exon 5) was related with the its mutation (coefficient of association was 0.410, P value < 0.05).</p><p><b>CONCLUSION</b>Arsenic pollution caused by coal-burning can cause the hypermethylation of p53 gene in promoter region, hypomethylation and mutation of p53 gene (exon 5), and the changes of methylation of p53 gene are related with its mutation and might be one of the important etiological factors of arsenic pathogenicity or carcinogenesis.</p>

Expression of DNA methyltransferase 1 mRNA in patients of endemic arsenism and its clinical significances / 中国地方病学杂志

Objective To investigate the transcription and expression of DNA methyltransferase 1 (DNMT1) mRNA in endemic arsenism patients by burning coal usage,to probe its effects on the development and carcinogenesis of arsenism. Methods In 2008,68 arsenism patients(including 24 mild cases,28 moderate cases and 16 severe cases) were selected in the areas with endemic arsenism according to Standarding of Diagnosis for Endemic Arsenism from Xingren county,Guizhou province. Among the subjects,40 cases were diagnosed by pathological methods,and they were divided into general pathological changes(20),precancerous(14) and cancerous group(6). Tweleve kilometer away from the endemic arsenism area,23 controls were selected in Daguoduo village (non-arsenism exposure). Under the principle of informed consent,blood samples were collected from individuals. The mRNA expression of DNMTI was detected by real-time quantitative reverse transcription polymerase chain reaction(FQ-PCR). At the same time,skin tissue samples were collected from the voluntary surgical treatment patients with endemic arsenism (total 61 cases,including 34 general pathological changes cases,21 precancerous cases and 6 cancerous cases) and from the control(15 cases). DNMT1 protein was detected by immunohistochemical method.Results Average level of DNMT1 mRNA were 0.221 83±0.595 09,0.246 11±0.509 79 and 0.389 27±0.411 33 respectively among mild,moderate and severe arsenism group. DNMT1 mRNA level of mild and moderate group were obviously lower than the control group(0.695 95±0.463 98,all P < 0.01). The mRNA average level of DNMT1 were 0.320 64±0.547 46,0.313 09±0.529 13 and 0.159 07±0.342 56 individually among general pathological changes,precancerous and cancerous group,which were obviously lower than the control group(0.695 95±0.463 98,all P < 0.05). The expression rates of DNMT1 protein in skin were 88.24%(30/34),100%(21/21) and 100% (6/6) among general pathological changes,precancerous and cancerous group were higher than the control group [0(0/15),all P < 0.01],and the extent of expression gradually increased with the aggravation of skin damage(r,= 0.740,P < 0.01). Conclusions DNMT1 participated in the development of the arsenism. High expression of its protein was an early event during the process of the arsenism. DNMT1 may be the new target markers for early diagnosis and treatment of arsenism.

Role of protein kinase C/NF-kappa B signal pathway In activation of T lymphocytes In human exposed to coal-arsenic / 中国地方病学杂志

Objective To investigate the activation of T lymphocytes in human peripheral blood and the signaling molecules in protein kinase C/nuclear factor KB(PKC/NF-κB) pathway expressivity or activity changes in human peripheral blood mononuclear cells(PBMCs) exposed to coal-arsenic,to explore the role of PKC/NF-κB signal pathway in activation of T cells in human exposed to coal-arsenic. Methods Blood samples were collected from individuals who lived in arsenism area of coal-burning in Guizhou province, and were divided into asymptomatically exposed group (12),mild arsenism group (33),moderate arsenism group (34) and severe arscnism group (15) according to Diagnosis Standard for Endemic Arsenism (WS/T 211-2001). The individuals who lived in non-arsenism area were control group(27). The ratio of activated T ceils was analyzed by flow cytometry. DNA binding activity of NF-κB in PBMCs was evaluated by electrophoretic mobility shift assay(EMSA). The expression of PKCθ and phospho-PKCθ(pPKCθ) in PBMCs were detected with western blotting analysis. Results The ratio of activating T cells in asymptomatically exposed group[(21.76±15.31)%],mild arsenism group[(18.41±11.36)%],moderate arsenism group[(17.78±11.93)%]and severe arsenism group[(18.79±13.38)%]were all higher than that of control group[(3.19±2.12)%],the difference among all groups being statistically significant(F = 7.893,P < 0.05). DNA binding activity of PBMCs NF-κB in asymptomatically exposed group,mild arsenism group,moderate arsenism group and severe arsenism group(1.49±0.24,1.58±0.30,1.57±0.34,1.51±0.16) were higher than that of the control group(1.30±0.17),the difference being statistically sign/ficant(P < 0.05 or < 0.01). The expression of PBMCs pPKCθ in mild arsenism group,moderate arsenism group and severe arsenism group(0.64± 0.14,0.64±0.27,0.62±0.12) were all lower than that of the control group(0.93±0.20),the difference being statistically significant(P < 0.05). There were significant negative correlations between the expression of pPKCθ and the activity of NF-κB(r =-0.565,P < 0.01). There were significant positive correlations between the activity of NF-κB and the ratio of activating T cells(r = 0.546,P < 0.01). Conclusion Coal-arsenic enhances the DNA binding activity of NF-κB,reduces the expression of PBMCs pPKCθ in human PBMCs and up-regulates the activity of T cells. It suggests that the PKC/NF-κB signal might be one of transduction pathway via activating of T cells by coal-arsenic.

Comparative analysis of environmental risk factors in nine years in an area polluted by arsenic coal-burning in Guizhou Province / 中国地方病学杂志

Objective To comparatively analyze the changes of environmental risk factors in 9 years in an area polluted by arsenic coal-burning in Xingren County of Guizhou Province,in order to provide evidence for reasoning the occurrence and development as well as its effective prevention and control.Methods Epidemiological sampling methods was used to conduct follow-up investigation on 181 arsenism patients who were diagnosed in 1998 in arsenic polluted area.Control group included 65 residents who lived far from polluted area of 12 km.The follow up investigation included age,sexuality,family economic situation,time of use or stop use of arsenic coal, ventilation of the room,desiccation of food etc.Diethyl dithiocarbamate silver(Ag-DDC)method was used to detect arsenic content of coal,soil,air,water and rice,corn,chili;Single factor and multivariate factors non-conditional Logistic regression models were used to analyze exposure factors of patients and related environmental risk factom, and the differences of those in 1998 and 2006 were compared. Results The arsenic content in indoor and outdoor air,coal,chili and corn went down from 0.0880 and 0.0220 mg/m3,397.20,45.07 and 2.64 mg/kg in 1998 to 0.0790 and 0.0070 mg/m3,93.01,3.46 and 1.50 mg/kg in 2006. Arsenic contents of other samples were less than national standard. The analysis of single factor and multivariate factors non-conditional Logistic regression showed that time of using high arsenic coal,age,fluorosis and smoking(x2 = 50.159,12.195,37.69,6.358,P ＜ 0.05 or ＜ 0.01 ) were still the main risk factors for arsenism,while family economic situation was still influential factors (X2 = 4.614,P ＜ 0.05);Ventilation of the room changed from a risk factors at 1998 to an influencing factors at 2006(X2 = 38.093,P ＜ 0.01 ). Single factor non-conditional Logistic regression model analysis showed that food desiccation by arsenic coal-burning and educational level were no longer risk and influencing factors,while food preservation and gender had become influencing factors(x2 = 17.463,11.004,all P ＜ 0.01 ) nine years after. Conclusions Environmental arsenic pollution in arsenism area in Guizhou Province has been obviously improved after nine years. However,the continued existence of low doses of arsenic pollution is still a major cause of failure of controlling arsenism. Time of using high arsenic coal,age,smoking,fluorosis,family economic situation and ventilating room are closely related to the occurrence and the development of arsenism. Prohibition of use of high arsenic coal,furnace improvement,health education and economic development are effective measures

Relationship between myeloperoxidase and catalase genetic polymorphism and their activities with arsenic poisoning caused by coal-burning / 中国地方病学杂志

Objective To detect genetic polymorphism of myeloperoxidase (MPO) gene and catalase (CAT) gene and their activities, and to analyze their relationship with arsenic poisoning caused by coal-burning. Methods One hundred and thirty arsenic poisoning patients were chosen as case group in Jiaole Village, Xingren County, Guizhou Province(an endemic area). One hundred and forty healthy residents living in 13 km away were chosen as control group. Their blood was collected. Polymerase chain reaction-restriction fragment length polymorphism technique(PCR-RFLP) was used to detect polymorphism of MPO-463G/A and CAT-262C/T. Ultraviolet spectmphotometer method was used to detect myeloperoxidase activity. Chromatometry method was used to detect catalase activity. Results The genotype frequency of MPO-463G/A at GG, GA, AA site was 47.24%(60/127), 44.09%(56/127),8.67% (11/127) in case group and 42.34% (58/137),48.17% (66/137)1,9.49% (13/137) in control group, respectively. The difference between the two groups was not significant(χ2 = 0.642, P > 0.05). The genotype frequency of CAT-262C/T, at CC, CT, TT site was 65.60%(82/125),28.80%(36/125),5.60%(7/125) in case group and 76.51%(101/132), 18.94% (25/132) ,4.55% (6/132) in control group, respectively, without significant difference (χ2 =3.845, P>0.05). The relationship between polymorphism of MPO-463G/A and CAT-262C/T and the risk of arsenic poisoning was not found in this study(ORadj= 1.36, 95%CI: 0.74-2.50 for MPO; ORadj=1.35, 95%CI: 0.69-2.63 for CAT). The activities of MPO and CAT were (25.30±8.70)U/L and (2.80± 1.09)×103 U/L in case group, while (22.76±7.59)U/L and (3.90±1.01)×103U/L in control group with a significant difference(F=0.760 for MPO, F=0.855 for CAT, all P < 0.05). The genotype of MPO-463G/A and CAT-262C/T was not found to have relationship with the activities of MPO, CAT(F=1.312,2.822 for MPO; F= 0.151,0.036 for CAT, P>0.05). Conclusions Genetic polymorphism of MPO-463G/A and CAT-262C/T is not found to have relationship with arsenic poisoning. Arsenic can lead to the change of MPO and CAT activity, which, however, may not be affected by MPO-463G/A and CAT-262C/T polymorphism.

Application of benchmark dose on the study of people's liver dysfunction induced by arsenic-coal burning and its significance / 中国地方病学杂志

Objective To explore the biological exposure limit of liver dysfunction induced by arsenic-coal burning, and screen sensitive biornarkers for its' liver dysfunction monitoring. Methods One hundred and eighteen subjects from the exposed area and 50 control from non-pollution area were studied. Their urinary and hair contents of arsenic were tested as exposure biomarkers by Ag-DDC assay. Total bile acid(TBA, detected by enzymatic cycling method), glutathione S-transferase (GSTs, detected by chemical colorimetry) and γ-glutamyl transpeptidase (γ-GT, detected by colorimetry of diazotization reagent) were used as biomarkers indicating liver cell damage. were used as liver fibrosis biomarkers. The benchmark dose (BMD) and the lower confidence limit of benchmark dose(BMDL) of urinary and hair arsenic were calculated. Sensitivity of each biomarker was estimated according to the BMD and BMDL value. Results The geometric mean of urinary and hair arsenic(98.50 mg/kg Cr, 7.42 mg/kg) μg/L) in the exposed group were significantly higher than urinary and hair arsenic (22.98 mg/kg Cr, 1.28 mg/kg) and each biomarker in the control group(4.63 μmol/L, 13.76 U/L,36.45 U/L,54.62 μg/L,74.45 μg/L,54.81 μg/L, P<0.01). Significant dose-effect relationship existed between urinary and hair arsenic contents and each biomarker. BMD and BMDL value of urinary arsenic was 49.53-101.96 mg/kg Cr and 39.02-70.15 mg/kg Cr, respectively. Those of hair arsenic were 3.04-5.02 mg/kg and 2.36-3.25 mg/kg, respectively. According to BMD and BMDL value of urinary and hair arsenic, the sensitivity of biomarkers decreased in the order of GSTs, TBA and Conclusions According to the lowest BMD and BMDL of urinary and hair arsenic, averaged reference value of urinary and hair arsenic in the local normal population, we suggest urinary 35.0 mg/kg Cr and hair 2.5 mg/kg as their biological exposure limits for those with liver dysfunction induced by arsenic-coal burning. GSTs, TBA, γ-GT and HA, Ⅳ. C, PC-Ⅲ can respectively reflect liver cell damage and liver fibrosis caused by arsenic-coal burning in different degrees, among which, GSTs and HA are the most sensitive biomarkers respectively for liver cell damage and liver fibrosis.

Influence of coal-arsenic exposure on human T cells proliferation and its mechanism / 中国地方病学杂志

Objective To explore the influence of coal-arsenic exposure on human T cells proliferation and its mechanism.Methods Blood samples colleoted from individuals which lived in arsenism area of coal-burning type and non-arsenism area in Guizhou Province were divided into exposed group(17),mild(35),moderate(38) and severe arsenism group(19)and control group(35)according to Diagnosis Smndard for Endemic Arsenism (WS/T 211-2001).T cell stimulation index wag determined by methyl thiazolyl tetrazolium(MTT)colorimetric method.The intracellular Ca2+ exponential(IECa2+)in peripheral blood mononuclear cell(PBMC)was analyzed by Fho-3/AM dye and flow cytometry.DNA binding activity of actively T cells nuclear factor(NF-AT)in PBMC was evaluated by electrophoretie mobility shift assay(EMSA).Results Concanavalin A(ConA)stimulation decreased the T cells stimulation indexes in exposed group,mild,moderate and severe arsenism groups(1.315±0.962, 1.611±1.224,1.114±0.545,1.289±0.875)compared with control group(2.322±1.241),all the differences being statistically significant(P＜0.01).After stimulated by anti-CD3 monoclonal antibody(McAb),the T cells stimulation index in exposed group,mild,moderate and severe arsenism group(0.997±0.177,1.103±0.291,1.007±0.221, 0.957±0.205) were lower than that of control group(1.842±0.429,P ＜ 0.01 ). IECa2+ of PBMC after treated by anti-CD3 McAb in mild,moderate and severe arsenism group( 110.130±49.637,92.429±31.191,77.640± 35.372) were lower compared with control group(145.986±59.450,P ＜0.01 ). Moreover,IECa2+ in moderat and severe arsenism group were lower than exposed group(121.337±46.410,P ＜ 0.05). DNA binding activity of PBMC NF-AT in mild,moderate and severe arsenism group(1.354±0.446,1.290±0.291,1.159±0.411 ) were lowered than that of control group(1.722±0.291,P ＜ 0.01) and exposed group(1.611±0.294,P ＜ 0.05). Conclusions The coal-arsenic exposure can reduce the human T cells stimulation indexes,IECa2+ in PBMC and the DNA binding activity of NF-AT. It suggest that arsenic may suppress the proliferation ability of human T cells,which may be partly related to the influence of arsenic on T cell receptor(TCR)/CD3 signal transduetion pathway.