Xiaojiang Tang

Publications (12)33.23 Total impact

• Article: Toxicity of Trimethyltin and Dimethyltin in Rats and Mice.

  Xiaojiang Tang, Xin Wu, Amber M Dubois, Gang Sui, Banghua Wu, Guanchao Lai, Zhihong Gong, Hongbin Gao, Shenglai Liu, Zhiyong Zhong, Zhongning Lin, James Olson, Xuefeng Ren
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  ABSTRACT: Extensive uses of methyltin compounds in polyvinyl chloride (PVC) production have led to a dramatic increase of occupational-related methyltin poisoning accidents and the widespread contamination of methyltins in various environmental media. Here, we conducted studies to compare the acute toxicity induced by trimethyltin (TMT) and dimethyltin (DMT), and investigated the cumulative toxic effects of TMT in rats and mice. Neurobehavioral changes were observed in rats and mice treated with either DMT or TMT, but we also observed that both TMT and DMT exposure in rats significantly lowered the blood potassium level. Moreover, the cumulative toxic coefficient factor of TMT was 1.7 in rats versus 3.8 in mice, suggesting a high cumulative risk for rats and a moderate risk for mice. In summary, we demonstrated that acute and chronic exposure to methyltin compounds induced neurotoxicity and hypokalemia. Moreover, our study suggests that TMT can accumulate in the body and pose a risk for workers chronically exposed to a low dose of TMT.
  Bulletin of Environmental Contamination and Toxicology 03/2013; · 1.02 Impact Factor
• Article: Alterations in serum immunoglobulin levels in workers occupationally exposed to trichloroethylene.

  Luoping Zhang, Bryan A Bassig, Joseph L Mora, Roel Vermeulen, Yichen Ge, John D Curry, Wei Hu, Shen Min, Chuangyi Qiu, Zhiying Ji, [......], Songwang Liu, Weihong Guo, Mark P Purdue, Fei Yue, Laiyu Li, Martyn T Smith, Hanlin Huang, Xiaojiang Tang, Nathaniel Rothman, Qing Lan
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  ABSTRACT: Trichloroethylene (TCE) has been associated with a variety of immunotoxic effects and may be associated with an increased risk of non-Hodgkin lymphoma (NHL). Altered serum immunoglobulin levels have been reported in NHL patients and in animals exposed to TCE. Recently, we reported that occupational exposure to TCE is associated with immunosuppressive effects and immune dysfunction, including suppression of B cell counts and activation, even at relatively low levels. We hypothesized that TCE exposure would also affect immunoglobulin (Ig) levels in humans. We measured serum levels of IgG, IgM, and IgE, by enzyme-linked immunosorbent assay, in TCE-exposed workers (n=80) and unexposed controls (n=45), matched by age and gender, in a cross-sectional, molecular epidemiology study of occupational exposure to TCE in Guangdong, China. Exposed workers had about a 17.5% decline in serum levels of IgG compared to unexposed controls (p =0.0002). Similarly, serum levels of IgM were reduced by about 38% in workers exposed to TCE compared to unexposed controls (p < 0.0001). Serum levels of both IgG and IgM were significantly decreased in workers exposed to TCE levels below 12 ppm, the median exposure level. Adjustment for B cell counts had minimal impact on our findings. IgE levels were not significantly different between exposed and control subjects. These results provide further evidence that TCE is immunotoxic at relatively low exposure levels, and provide additional biologic plausibility for the reported association of TCE with NHL.
  Carcinogenesis 12/2012; · 5.70 Impact Factor
• Article: Occupational exposure to formaldehyde and alterations in lymphocyte subsets.

  H Dean Hosgood, Luoping Zhang, Xiaojiang Tang, Roel Vermeulen, Zhenyue Hao, Min Shen, Chuangyi Qiu, Yichen Ge, Ming Hua, Zhiying Ji, [......], Laura Beane Freeman, Xiaolin Ruan, Weihong Guo, Noe Galvan, Aaron Blair, Laiyu Li, Hanlin Huang, Martyn T Smith, Nathaniel Rothman, Qing Lan
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  ABSTRACT: BACKGROUND: Formaldehyde is used in many occupational settings, most notably in manufacturing, health care, and embalming. Formaldehyde has been classified as a human carcinogen, but its mechanism of action remains uncertain. METHODS: We carried out a cross-sectional study of 43 formaldehyde-exposed workers and 51 unexposed age and sex-matched controls in Guangdong, China to study formaldehyde's early biologic effects. To follow up our previous report that the total lymphocyte count was decreased in formaldehyde-exposed workers compared with controls, we evaluated each major lymphocyte subset (i.e., CD4(+) T cells, CD8(+) T cells, natural killer [NK] cells, and B cells) and T cell lymphocyte subset (CD4(+) naïve and memory T cells, CD8(+) naïve and memory T cells, and regulatory T cells). Linear regression of each subset was used to test for differences between exposed workers and controls, adjusting for potential confounders. RESULTS: Total NK cell and T cell counts were about 24% (P = 0.037) and 16% (P = 0.0042) lower, respectively, among exposed workers. Among certain T cell subsets, decreased counts among exposed workers were observed for CD8(+) T cells (P = 0.026), CD8(+) effector memory T cells (P = 0.018), and regulatory T cells (CD4(+) FoxP3(+) : P = 0.04; CD25(+) FoxP3(+) : P = 0.008). CONCLUSIONS: Formaldehyde-exposed workers experienced decreased counts of NK cells, regulatory T cells, and CD8(+) effector memory T cells; however, due to the small sample size; these findings need to be confirmed in larger studies. Am. J. Ind. Med. © 2012 Wiley Periodicals, Inc.
  American Journal of Industrial Medicine 07/2012; · 1.63 Impact Factor
• Article: Elevated urinary levels of kidney injury molecule-1 among Chinese factory workers exposed to trichloroethylene.

  Roel Vermeulen, Luoping Zhang, Annejet Spierenburg, Xiaojian Tang, Joseph V Bonventre, Boris Reiss, Min Shen, Martyn T Smith, Chuangyi Qiu, Yichen Ge, [......], Yuxuan Xie, Fei Yue, Weihong Guo, Mark Purdue, Laura E Beane Freeman, Venkata Sabbisetti, Laiyu Li, Hanlin Huang, Nathaniel Rothman, Qing Lan
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  ABSTRACT: Epidemiological studies suggest that trichloroethylene (TCE) exposure may be associated with renal cancer. The biological mechanisms involved are not exactly known although nephrotoxicity is believed to play a role. Studies on TCE nephrotoxicity among humans, however, have been largely inconsistent. We studied kidney toxicity in Chinese factory workers exposed to TCE using novel sensitive nephrotoxicity markers. Eighty healthy workers exposed to TCE and 45 comparable unexposed controls were included in the present analyses. Personal TCE exposure measurements were taken over a 2-week period before urine collection. Ninety-six percent of workers were exposed to TCE below the current US Occupational Safety and Health Administration permissible exposure limit (100 ppm 8h TWA), with a mean (SD) of 22.2 (35.9) ppm. Kidney injury molecule-1 (KIM-1) and Pi-glutathione S transferase (GST) alpha were elevated among the exposed subjects as compared with the unexposed controls with a strong exposure-response association between individual estimates of TCE exposure and KIM-1 (P < 0.0001). This is the first report to use a set of sensitive nephrotoxicity markers to study the possible effects of TCE on the kidneys. The findings suggest that at relatively low occupational exposure levels a toxic effect on the kidneys can be observed. This finding supports the biological plausibility of linking TCE exposure and renal cancer.
  Carcinogenesis 06/2012; 33(8):1538-41. · 5.70 Impact Factor
• Source

  Available from: Roel Vermeulen

  Article: Decreased Numbers of CD4(+) Naive and Effector Memory T Cells, and CD8(+) Naïve T Cells, are Associated with Trichloroethylene Exposure.

  H Dean Hosgood, Luoping Zhang, Xiaojiang Tang, Roel Vermeulen, Chuangyi Qiu, Min Shen, Martyn T Smith, Yichen Ge, Zhiying Ji, Jun Xiong, [......], Boris Reiss, Songwang Liu, Yuxuan Xie, Weihong Guo, Noe Galvan, Laiyu Li, Zhenyue Hao, Nathaniel Rothman, Hanlin Huang, Qing Lan
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  ABSTRACT: Trichloroethylene (TCE) is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE's carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE's early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4(+) T cells, CD8(+) T cells, natural killer cells, and B cells) were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors, and/or lymphocyte survival. To explore which T lymphocyte subsets are affected in the same study population, we investigated the effect of TCE exposure on the numbers of CD4(+) naïve and memory T cells, CD8(+) naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4(+) and CD8(+) naïve T cell counts were about 8% (p = 0.056) and 17% (p = 0.0002) lower, respectively, among exposed workers. CD4(+) effector memory T cell counts were decreased by about 20% among TCE-exposed workers compared to controls (p = 0.001). The selective targeting of TCE on CD8(+) naive and possibly CD4(+) naive T cells, and CD4(+) effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure.
  Frontiers in oncology. 01/2011; 1:53.
• Source

  Available from: Laura Beane Freeman

  Article: Occupational exposure to trichloroethylene is associated with a decline in lymphocyte subsets and soluble CD27 and CD30 markers.

  Qing Lan, Luoping Zhang, Xiaojiang Tang, Min Shen, Martyn T Smith, Chuangyi Qiu, Yichen Ge, Zhiying Ji, Jun Xiong, Jian He, [......], Mark P Purdue, Noe Galvan, Kerry X Xin, Wei Hu, Laura E Beane Freeman, Aaron E Blair, Laiyu Li, Nathaniel Rothman, Roel Vermeulen, Hanlin Huang
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  ABSTRACT: Occupational cohort and case-control studies suggest that trichloroethylene (TCE) exposure may be associated with non-Hodgkin lymphoma (NHL) but findings are not consistent. There is a need for mechanistic studies to evaluate the biologic plausibility of this association. We carried out a cross-sectional molecular epidemiology study of 80 healthy workers that used TCE and 96 comparable unexposed controls in Guangdong, China. Personal exposure measurements were taken over a three-week period before blood collection. Ninety-six percent of workers were exposed to TCE below the current US Occupational Safety and Health Administration Permissible Exposure Limit (100 p.p.m. 8 h time-weighted average), with a mean (SD) of 22.2 (36.0) p.p.m. The total lymphocyte count and each of the major lymphocyte subsets including CD4+ T cells, CD8+ T cells, natural killer (NK) cells and B cells were significantly decreased among the TCE-exposed workers compared with controls (P < 0.05), with evidence of a dose-dependent decline. Further, there was a striking 61% decline in sCD27 plasma level and a 34% decline in sCD30 plasma level among TCE-exposed workers compared with controls. This is the first report that TCE exposure under the current Occupational Safety and Health Administration workplace standard is associated with a decline in all major lymphocyte subsets and sCD27 and sCD30, which play an important role in regulating cellular activity in subsets of T, B and NK cells and are associated with lymphocyte activation. Given that altered immunity is an established risk factor for NHL, these results add to the biologic plausibility that TCE is a possible lymphomagen.
  Carcinogenesis 09/2010; 31(9):1592-6. · 5.70 Impact Factor
• Article: Occupational exposure to formaldehyde, hematotoxicity and leukemia-specific chromosome changes in cultured myeloid progenitor cells - response.

  Luoping Zhang, Zhiying Ji, Weihong Guo, Alan E Hubbard, Noe Galvan, Kerry X Xin, Mariko Azuma, Martyn T Smith, Xiaojiang Tang, Chuangyi Qiu, [......], Michael Hauptmann, Patricia Stewart, Joseph F Fraumeni, Qing Lan, Roel Vermeulen, Boris Reiss, Songwang Liu, Jun Xiong, Sungkyoon Kim, Stephen M Rappaport
  Cancer Epidemiology Biomarkers &amp Prevention 07/2010; 19(7):1884-5. · 4.12 Impact Factor
• Article: Mechanism underlying hypokalemia induced by trimethyltin chloride: Inhibition of H+/K+-ATPase in renal intercalated cells.

  Xiaojiang Tang, Xiaojun Yang, Guanchao Lai, Jinhui Guo, Lihua Xia, Banghua Wu, Yuxuan Xie, Ming Huang, Jiabin Chen, Xiaolin Ruan, Gang Sui, Yichen Ge, Wulin Zuo, Na Zhao, Guanghua Zhu, Jinxin Zhang, Laiyu Li, Wenliang Zhou
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  ABSTRACT: Trimethyltin chloride (TMT), a byproduct of plastic stabilizers, has caused 67 poisoning accidents in the world; more than 98% (1814/1849) of the affected patients since 1998 have been in China. As a long-established toxic chemical, TMT severely affects the limbic system and the cerebellum; however, its relationship with hypokalemia, a condition observed in the majority of the cases in the last decade, remains elusive. To understand the mechanism underlying hypokalemia induced by TMT, Sprague-Dawley (SD) rats were administered TMT to determine the relationship between H(+)/K(+)-ATPase activity and the blood and urine K(+) concentration and pH, respectively. H(+)/K(+)-ATPase protein and mRNA were observed too. In vitro changes to intracellular pH, K(+) channels in renal cells were measured. The results showed that TMT increased potassium leakage from the kidney, raised urine pH, and inhibited H(+)/K(+)-ATPase activity both in vitro and in vivo. In the tested animals, H(+)/K(+)-ATPase activity was positively correlated with the decrease of plasma K(+) and blood pH but was negatively correlated with the increase of urine K(+) and urine pH (P<0.01), while TMT did not change the expression of H(+)/K(+)-ATPase protein and mRNA. TMT decreased intracellular pH and opened K(+) channels in renal intercalated cells. Our findings suggest TMT can directly inhibit the activity of H(+)/K(+)-ATPases in renal intercalated cells, reducing urine K(+) reabsorption and inducing hypokalemia.
  Toxicology 03/2010; 271(1-2):45-50. · 3.68 Impact Factor
• Article: Occupational exposure to formaldehyde, hematotoxicity, and leukemia-specific chromosome changes in cultured myeloid progenitor cells.

  Luoping Zhang, Xiaojiang Tang, Nathaniel Rothman, Roel Vermeulen, Zhiying Ji, Min Shen, Chuangyi Qiu, Weihong Guo, Songwang Liu, Boris Reiss, [......], Mariko Azuma, Michael Hauptmann, Jun Xiong, Patricia Stewart, Laiyu Li, Stephen M Rappaport, Hanlin Huang, Joseph F Fraumeni, Martyn T Smith, Qing Lan
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  ABSTRACT: There are concerns about the health effects of formaldehyde exposure, including carcinogenicity, in light of elevated indoor air levels in new homes and occupational exposures experienced by workers in health care, embalming, manufacturing, and other industries. Epidemiologic studies suggest that formaldehyde exposure is associated with an increased risk of leukemia. However, the biological plausibility of these findings has been questioned because limited information is available on the ability of formaldehyde to disrupt hematopoietic function. Our objective was to determine if formaldehyde exposure disrupts hematopoietic function and produces leukemia-related chromosome changes in exposed humans. We examined the ability of formaldehyde to disrupt hematopoiesis in a study of 94 workers in China (43 exposed to formaldehyde and 51 frequency-matched controls) by measuring complete blood counts and peripheral stem/progenitor cell colony formation. Further, myeloid progenitor cells, the target for leukemogenesis, were cultured from the workers to quantify the level of leukemia-specific chromosome changes, including monosomy 7 and trisomy 8, in metaphase spreads of these cells. Among exposed workers, peripheral blood cell counts were significantly lowered in a manner consistent with toxic effects on the bone marrow and leukemia-specific chromosome changes were significantly elevated in myeloid blood progenitor cells. These findings suggest that formaldehyde exposure can have an adverse effect on the hematopoietic system and that leukemia induction by formaldehyde is biologically plausible, which heightens concerns about its leukemogenic potential from occupational and environmental exposures.
  Cancer Epidemiology Biomarkers &amp Prevention 01/2010; 19(1):80-8. · 4.12 Impact Factor
• Source

  Available from: uoeh-u.ac.jp

  Article: Characterization of liver injury associated with hypersensitive skin reactions induced by trichloroethylene in the guinea pig maximization test.

  Xiaojiang Tang, Bingling Que, Xiangrong Song, Senhua Li, Xiaojun Yang, Hailan Wang, Hanlin Huang, Michihiro Kamijima, Tamie Nakajima, Yongcheng Lin, Laiyu Li
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  ABSTRACT: Trichloroethylene (TCE) can induce non-dose-related hepatitis, possibly classified as delayed-type hypersensitivity (immune-mediated hepatitis), as well as dose-related toxic liver injury. However, the difference in pathophysiology between the two kinds of hepatitis remains unknown. This study aimed to characterize the liver injury associated with hypersensitive skin reactions induced by TCE in guinea pigs. As a model of dose-related acute toxic liver injury, the animals were treated with intradermal injection (ii) (0, 167, 500, 1500 or 4500 mg/kg of TCE) or dermal patch (dp) (0 or 900 mg/kg of TCE). The guinea pig maximization test (GPMT) was also carried out as a model of immune-mediated liver injury, in which the total TCE dosage was below 340 mg/kg. In the group of TCE 4500 mg/kg (ii), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased (p<0.01), while total protein and globulin decreased (p<0.05). Evident fatty degeneration, hepatic sinusoid dilation and inflammatory cell infiltration were observed. No significant change was found in animals treated with TCE of doses below 500 mg/kg (ii) or 900 mg/kg (dp). In the GPMT, sensitization rates of TCE-induced dermal allergy were 66%. ALT, AST, lactate dehydrogenase and the relative liver weight increased significantly (p<0.05) while albumin, IgA and gamma-glutamyl transpeptidase decreased significantly (p<0.05). Lesions of ballooning changes were observed in liver pathology. Thus, TCE could cause both acute-type toxic liver injury and immune-mediated liver injury, the so-called delayed-type hypersensitivity at doses below the dosage for toxic liver injury. Interestingly, the histopathological features were quite different: fatty degeneration was most prominent in the former, and ballooning in the latter.
  Journal of Occupational Health 04/2008; 50(2):114-21. · 1.55 Impact Factor
• Article: [Effect of fluoroacetamide on cardiomyocytes of rat and the antidotal effect of acetamide].

  Guanghua Zhu, Lihua Xia, Guanzhao Lai, Laiyu Li, Jianxun Huang, Xiaojiang Tang
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  ABSTRACT: To observe the effect of fluoroacetamide on cardiomyocytes of rat and the antidotal effect of acetamide. 4 groups of SD rats were treated with various dosages of fluoroacetamid(p.o.) and 2 groups of them were treated with acetamide(i.p.). The changes of cardiomyocytes and serum AST, LDH, CK, CK-MB and HBDH were measured at different intervals after poisoning. In the group treated with fluoroacetamid 8 mg/kg. bw, serum AST[(589.58 +/- 821.72) U/L], CK[(916.78 +/- 343.55) U/L], HBDH[(504.47 +/- 148.88) U/L] raised obviously compared with control[(187.70 +/- 46.87), (755.65 +/- 498.90), (347.25 +/- 228.40) U/L respectively] (P < 0.01), and the pathological findings such as degeneration, liquefactive necrosis and filtration of inflammatory cells in cardiac muscles were observed 24 hours later, while all the male dead within 3 days. In the group treated with fluoroacetamid 4 mg/kg. bw, serum LDH and HBDH rose significantly compared with control(P < 0.01) 5 day later. On the day of 10, myocardial enzymes restored in all experiment groups with some interstitial fibroblastic proliferation. The pathological changes were reduced in the group treated with acetamide synchronously (100 mg/kg. bw). Acute intoxication of fluoroacetamide could damage cardiomyocytes while acetamide could reduce the injury of them, but the injury was reversible. The levels of serum myocardial enzymes could be a usable index for early diagnosis.
  Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases 08/2002; 20(4):300-3.
• Source

  Available from: Yang Bai

  Article: Formaldehyde in China: Production, consumption, exposure levels, and health effects

  Xiaojiang Tang, Yang Bai, Anh Duong, Martyn T. Smith, Laiyu Li, Luoping Zhang
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  ABSTRACT: Formaldehyde, an economically important chemical, is classified as a human carcinogen that causes nasopharyngeal cancer and probably leukemia. As China is the largest producer and consumer of formaldehyde in the world, the Chinese population is potentially at increased risk for cancer and other associated health effects. In this paper we review formaldehyde production, consumption, exposure, and health effects in China. We collected and analyzed over 200 Chinese and English documents from scientific journals, selected newspapers, government publications, and websites pertaining to formaldehyde and its subsequent health effects.Over the last 20 years, China's formaldehyde industry has experienced unprecedented growth, and now produces and consumes one-third of the world's formaldehyde. More than 65% of the Chinese formaldehyde output is used to produce resins mainly found in wood products — the major source of indoor pollution in China. Although the Chinese government has issued a series of standards to regulate formaldehyde exposure, concentrations in homes, office buildings, workshops, public places, and food often exceed the national standards. In addition, there have been numerous reports of formaldehyde-induced health problems, including poisoning and cancer. The lack of quality epidemiological studies and basic data on exposed populations emphasizes the need for more extensive studies on formaldehyde and its related health effects in China.
  Environment International.