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  1. Low level arsenic promotes progressive inflammatory angiogenesis and liver blood vessel remodeling in mice

    International Nuclear Information System (INIS)

    The vascular effects of arsenic in drinking water are global health concerns contributing to human disease worldwide. Arsenic targets the endothelial cells lining blood vessels, and endothelial cell activation or dysfunction may underlie the pathogenesis of both arsenic-induced vascular diseases and arsenic-enhanced tumorigenesis. The purpose of the current studies was to demonstrate that exposing mice to drinking water containing environmentally relevant levels of arsenic promoted endothelial cell dysfunction and pathologic vascular remodeling. Increased angiogenesis, neovascularization, and inflammatory cell infiltration were observed in Matrigel plugs implanted in C57BL/6 mice following 5-week exposures to 5-500 ppb arsenic [Soucy, N.V., Mayka, D., Klei, L.R., Nemec, A.A., Bauer, J.A., Barchowsky, A., 2005. Neovascularization and angiogenic gene expression following chronic arsenic exposure in mice. Cardiovasc.Toxicol 5, 29-42]. Therefore, functional in vivo effects of arsenic on endothelial cell function and vessel remodeling in an endogenous vascular bed were investigated in the liver. Liver sinusoidal endothelial cells (LSEC) became progressively defenestrated and underwent capillarization to decrease vessel porosity following exposure to 250 ppb arsenic for 2 weeks. Sinusoidal expression of PECAM-1 and laminin-1 proteins, a hallmark of capillarization, was also increased by 2 weeks of exposure. LSEC caveolin-1 protein and caveolae expression were induced after 2 weeks of exposure indicating a compensatory change. Likewise, CD45/CD68-positive inflammatory cells did not accumulate in the livers until after LSEC porosity was decreased, indicating that inflammation is a consequence and not a cause of the arsenic-induced LSEC phenotype. The data demonstrate that the liver vasculature is an early target of pathogenic arsenic effects and that the mouse liver vasculature is a sensitive model for investigating vascular health effects of arsenic

  2. Stimulatory Effects of Arsenic-Tolerant Soil Fungi on Plant Growth Promotion and Soil Properties

    OpenAIRE

    Srivastava, Pankaj Kumar; Shenoy, Belle Damodara; Gupta, Manjul; Vaish, Aradhana; Mannan, Shivee; Singh, Nandita; Tewari, Shri Krishna; Tripathi, Rudra Deo

    2012-01-01

    Fifteen fungi were obtained from arsenic-contaminated agricultural fields in West Bengal, India and examined for their arsenic tolerance and removal ability in our previous study. Of these, the four best arsenic-remediating isolates were tested for plant growth promotion effects on rice and pea in the present study. A greenhouse-based pot experiment was conducted using soil inocula of individual fungi. The results indicated a significant (P

  3. Arsenic

    Science.gov (United States)

    ... of countries, including Argentina, Bangladesh, Chile, China, India, Mexico, and the United States of America. Drinking-water, ... ingestion of inorganic arsenic include developmental effects, neurotoxicity, diabetes, pulmonary disease and cardiovascular disease. Arsenic-induced myocardial ...

  4. Low doses of arsenic, via perturbing p53, promotes tumorigenesis.

    Science.gov (United States)

    Ganapathy, Suthakar; Li, Ping; Fagman, Johan; Yu, Tianqi; Lafontant, Jean; Zhang, Guojun; Chen, Changyan

    2016-09-01

    In drinking water and in workplace or living environments, low doses of arsenic can exist and operate as a potent carcinogen. Due to insufficient understanding and information on the pervasiveness of environmental exposures to arsenic, there is an urgent need to elucidate the underlying molecular mechanisms of arsenic regarding its carcinogenic effect on human health. In this study, we demonstrate that low doses of arsenic exposure mitigate or mask p53 function and further perturb intracellular redox state, which triggers persistent endoplasmic reticulum (ER) stress and activates UPR (unfolded protein response), leading to transformation or tumorigenesis. Thus, the results suggest that low doses of arsenic exposure, through attenuating p53-regulated tumor suppressive function, change the state of intracellular redox and create a microenvironment for tumorigenesis. Our study also provides the information for designing more effective strategies to prevent or treat human cancers initiated by arsenic exposure. PMID:27425828

  5. Arsenicals produce stable progressive changes in DNA methylation patterns that are linked to malignant transformation of immortalized urothelial cells

    International Nuclear Information System (INIS)

    Aberrant DNA methylation participates in carcinogenesis and is a molecular hallmark of a tumor cell. Tumor cells generally exhibit a redistribution of DNA methylation resulting in global hypomethylation with regional hypermethylation; however, the speed in which these changes emerge has not been fully elucidated and may depend on the temporal location of the cell in the path from normal, finite lifespan to malignant transformation. We used a model of arsenical-induced malignant transformation of immortalized human urothelial cells and DNA methylation microarrays to examine the extent and temporal nature of changes in DNA methylation that occur during the transition from immortal to malignantly transformed. Our data presented herein suggest that during arsenical-induced malignant transformation, aberrant DNA methylation occurs non-randomly, progresses gradually at hundreds of gene promoters, and alters expression of the associated gene, and these changes are coincident with the acquisition of malignant properties, such as anchorage independent growth and tumor formation in immunocompromised mice. The DNA methylation changes appear stable, since malignantly transformed cells removed from the transforming arsenical exhibited no reversion in DNA methylation levels, associated gene expression, or malignant phenotype. These data suggest that arsenicals act as epimutagens and directly link their ability to induce malignant transformation to their actions on the epigenome.

  6. Ionizing radiation in tumor promotion and progression

    International Nuclear Information System (INIS)

    Chronic exposure to beta radiation has been tested as a tumor promoting or progressing agent. The dorsal skins of groups of 25 female SENCAR mice were chemically initiated with a single exposure to DMBA, and chronic exposure to strontium-90/yttrium-90 beta radiation was tested as a stage 1, stage 2 or complete skin tumor promoter. Exposure of initiated mice to 0.5 gray twice a week for 13 weeks produced no papillomas, indicating no action as a complete promoter. Another similar group of animals was chemically promoted through stage 1 (with TPA) followed by 0.5 gray of beta radiation twice a week for 13 weeks. Again no papillomas developed indicating no action of chronic radiation as a stage 2 tumor promoter. The same radiation exposure protocol in another DMBA initiated group receiving both stage 1 and 2 chemical promotion resulted in a decrease in papilloma frequency, compared to the control group receiving no beta irradiation, indicating a tumor preventing effect of radiation at stage 2 promotion, probably by killing initiated cells. Chronic beta radiation was tested three different ways as a stage 1 tumor promoter. When compared to the appropriate control, beta radiation given after initiation as a stage 1 promoter (0.5 gray twice a week for 13 weeks), after initiation and along with a known stage 1 chemical promoter (1.0 gray twice a week for 2 weeks), or prior to initiation as a stage 1 promoter (0.5 gray twice a week for 4 weeks), each time showed a weak (∼ 15% stimulation) but statistically significant (p<0.01) ability to act as a stage 1 promoter. When tested as a tumor progressing agent delivered to pre-existing papillomas, beta radiation (0.5 gray twice a week for 13 weeks) increased carcinoma frequency from 0.52 to 0.68 carcinoma/animal, but this increase was not statistically significant at the 95% confidence level. We conclude that in the addition to the known initiating, progressing and complete carcinogenic action of acute exposures to ionizing

  7. A high-selenium lentil dietary intervention in Bangladesh to counteract arsenic toxicity: study protocol for a randomized controlled trial

    OpenAIRE

    Regina M Krohn; Raqib, Rubhana; Akhtar, Evana; Vandenberg, Albert; Smits, Judit E. G.

    2016-01-01

    Background Millions of people worldwide are exposed to dangerous levels of arsenic (above the WHO water standard of 10 ppb) in drinking water and food. Lack of nutritious foods exacerbates the adverse health effects of arsenic poisoning. The micronutrient selenium is a known antagonist to arsenic, promoting the excretion of arsenic from the body. Studies are in progress examining the potential of using selenium supplement pills to counteract arsenic toxicity. We are planning a clinical trial ...

  8. Arsenic promotes angiogenesis in vitro via a heme oxygenase-1-dependent mechanism

    International Nuclear Information System (INIS)

    Angiogenesis and vessel remodeling are fundamental to the pathogenesis of a number of diseases caused by environmental arsenic exposure, including tumorigenesis and cardiovascular diseases. Arsenic (AsIII) has been shown to stimulate angiogenesis and vascular remodeling in vivo. However, the exact molecular mechanisms accounting for arsenic-induced angiogenesis are not clear. The present study investigates the role of heme oxygenase-1 (HO-1) in sodium arsenite-mediated angiogenesis in vitro. Transwell assay, three-dimensional Matrigel assay, RT-PCR, ELISA and immunoblotting were used to determine cell migration, vascular tube formation, mRNA and protein expression. Chromatin immunoprecipitation and luciferase assay were applied to examine the DNA binding with protein and HO-1 transcriptional activity. Here, we report that low concentrations of arsenite (0.1-1 μM) stimulated cell migration and vascular tube formation in human microvascular endothelial cells (HMVEC). Arsenite induced HO-1 mRNA and protein expression. Knock down of HO-1 expression decreased arsenite-induced VEGF expression, cell migration, and tube formation. We showed that arsenite promoted dissociation of Bach1 (a transcriptional repressor) from the HO-1 enhancers and increased Nrf2 binding to these elements. Site directed mutagenesis assay identified that Bach1 cysteine residues 557 and 574 were essential for the induction of HO-1 gene in response to arsenite. These findings demonstrate a role for HO-1 in arsenite-mediated angiogenesis in vitro.

  9. Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea.

    Science.gov (United States)

    Shagol, Charlotte C; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sundaram, Subbiah; Sa, Tongmin

    2014-01-01

    The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20 mM for NaAsO2 and 140 to 310 mM NaH2AsO4 · 7H2O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200 μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils. PMID:24737020

  10. Brevundimonas diminuta mediated alleviation of arsenic toxicity and plant growth promotion in Oryza sativa L.

    Science.gov (United States)

    Singh, Namrata; Marwa, Naina; Mishra, Shashank K; Mishra, Jyoti; Verma, Praveen C; Rathaur, Sushma; Singh, Nandita

    2016-03-01

    Arsenic (As), a toxic metalloid adversely affects plant growth in polluted areas. In the present study, we investigated the possibility of improving phytostablization of arsenic through application of new isolated strain Brevundimonas diminuta (NBRI012) in rice plant [Oryza sativa (L.) Var. Sarju 52] at two different concentrations [10ppm (low toxic) and 50ppm (high toxic)] of As. The plant growth promoting traits of bacterial strains revealed the inherent ability of siderophores, phosphate solubilisation, indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production which may be associated with increased biomass, chlorophyll and MDA content of rice and thereby promoting plant growth. The study also revealed the As accumulation property of NBRI012 strain which could play an important role in As removal from contaminated soil. Furthermore, NBRI012 inoculation significantly restored the hampered root epidermal and cortical cell growth of rice plant and root hair elimination. Altogether our study highlights the multifarious role of B. diminuta in mediating stress tolerance and modulating translocation of As in edible part of rice plant. PMID:26650422

  11. A Phytoremediation Strategy for Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    A Phytoremediation Strategy for Arsenic Progress Report May, 2005 Richard B. Meagher Principal Investigator Arsenic pollution affects the health of several hundred millions of people world wide, and an estimated 10 million Americans have unsafe levels of arsenic in their drinking water. However, few environmentally sound remedies for cleaning up arsenic contaminated soil and water have been proposed. Phytoremediation, the use of plants to extract and sequester environmental pollutants, is one new technology that offers an ecologically sound solution to a devastating problem. We propose that it is less disruptive to the environment to harvest and dispose of several thousand pounds per acre of contaminated aboveground plant material, than to excavate and dispose of 1 to 5 million pounds of contaminated soil per acre (assumes contamination runs 3 ft deep). Our objective is to develop a genetics-based phytoremediation strategy for arsenic removal that can be used in any plant species. This strategy requires the enhanced expression of several transgenes from diverse sources. Our working hypothesis is that organ-specific expression of several genes controlling the transport, electrochemical state, and binding of arsenic will result in the efficient extraction and hyperaccumulation of arsenic into aboveground plant tissues. This hypothesis is supported by theoretical arguments and strong preliminary data. We proposed six Specific Aims focused on testing and developing this arsenic phytoremediation strategy. During the first 18 months of the grant we made significant progress on five Specific Aims and began work on the sixth as summarized below. Specific Aim 1: Enhance plant arsenic resistance and greatly expand sinks for arsenite by expressing elevated levels of thiol-rich, arsenic-binding peptides. Hyperaccumulation of arsenic depends upon making plants that are both highly tolerant to arsenic and that have the capacity to store large amounts of arsenic aboveground

  12. Research progress on toxicity and excretion of arsenic%砷的毒性及排砷研究进展

    Institute of Scientific and Technical Information of China (English)

    李羡筠

    2012-01-01

    砷是有毒的类金属元素,通过环境污染和职业性接触进入体内,对人体的皮肤、神经系统、心血管、肝脏及肾脏等有明显的损伤.在砷中毒治疗中,常用临床药物虽然排砷效果好,但具有一定的局限性,寻求一种高效、价廉、无不良反应且能广泛用于患者的排砷药物是当务之急.笔者就近年来国内外学者有关砷对机体的损害及排砷治疗的研究进展进行综述.%Arsenic is a toxic metalloid element, it enter the body through environmental pollution and occupational exposure, and may cause an obvious damage on skin, nervous system, cardiovascular system, liver and kidney. In the treatment of arsenic poisoning, although the common drugs have good effect on excretion of arsenic, there are some limitations. It is the urgent affair to find out an arsenic excretion drug which has good effect, low cost, less adverse reaction and extensive use. This article reviews the research progress on damages caused by arsenic and excretion of arsenic at home and abroad.

  13. Epithelial to mesenchymal transition in arsenic-transformed cells promotes angiogenesis through activating β-catenin–vascular endothelial growth factor pathway

    International Nuclear Information System (INIS)

    Arsenic exposure represents a major health concern increasing cancer risks, yet the mechanism of arsenic carcinogenesis has not been elucidated. We and others recently reported that cell malignant transformation by arsenic is accompanied by epithelial to mesenchymal transition (EMT). However, the role of EMT in arsenic carcinogenesis is not well understood. Although previous studies showed that short term exposure of endothelial cells to arsenic stimulated angiogenesis, it remains to be determined whether cells that were malignantly transformed by long term arsenic exposure have a pro-angiogenic effect. The objective of this study was to investigate the effect of arsenic-transformed human bronchial epithelial cells that underwent EMT on angiogenesis and the underlying mechanism. It was found that the conditioned medium from arsenic-transformed cells strongly stimulated tube formation by human umbilical vein endothelial cells (HUVECs). Moreover, enhanced angiogenesis was detected in mouse xenograft tumor tissues resulting from inoculation of arsenic-transformed cells. Mechanistic studies revealed that β-catenin was activated in arsenic-transformed cells up-regulating its target gene expression including angiogenic-stimulating vascular endothelial growth factor (VEGF). Stably expressing microRNA-200b in arsenic-transformed cells that reversed EMT inhibited β-catenin activation, decreased VEGF expression and reduced tube formation by HUVECs. SiRNA knockdown β-catenin decreased VEGF expression. Adding a VEGF neutralizing antibody into the conditioned medium from arsenic-transformed cells impaired tube formation by HUVECs. Reverse transcriptase-PCR analysis revealed that the mRNA levels of canonical Wnt ligands were not increased in arsenic-transformed cells. These findings suggest that EMT in arsenic-transformed cells promotes angiogenesis through activating β-catenin–VEGF pathway. - Highlights: • Arsenic-transformed cells that underwent EMT displayed a pro

  14. Progress in Promoting Research Reactor Coalitions

    International Nuclear Information System (INIS)

    This presentation treats of the IAEA's role in Promoting Research Reactor (RR) coalitions, presents the strategic view, the types of coalitions, the 2007-2008 activities and Results, and the upcoming activities. The RR Coalitions Progress is presented first (Initial discussions, project design, approval of NTI grant request, informal consultations and development of 'national' proposals, Number of 'models' identified, exploratory missions/meetings, initial implementation of several coalitions, IAEA coordination, ideas/proposals/ventures, initial support. Some countries, institutes, or users want access to reactor capabilities without, or in advance of, building a domestic facility. Some countries, institutes, or users need access to alternative capabilities to permit the closure/consolidation of marginal facilities. Cooperative arrangements will result in increased utilization for each participant. The results from the reactor view are as follows: cover increases in order levels or scientific research; cover facility outages (planned or un-planned); delegate 'less profitable' products and services; access capacity for new products and services; reduce transport needs by geographical optimization; reduce investment needs by contracting for complementary capabilities; reduce costs of medical radio-isotope for R and D; share best practices in operations and safety. The results from the stakeholder View are: Better information on what reactors can offer/provide; greater range of services; more proactive product and service support; greater reliability in supplies of products and services. The types of coalitions are of different forms to meet needs, capabilities, objectives of members. In general they start small, evolve, change form, expand as confidence grows. The role of the Scientific consortium is to: distribute excess demand, test new concepts for implementation at high-flux reactors, direct requests for access to most appropriate RR, share best practices

  15. Interleukin-17: A Promoter in Colorectal Cancer Progression

    OpenAIRE

    Dang Wu; Pin Wu; Qi Huang; Yang Liu; Jun Ye; Jian Huang

    2013-01-01

    It is widely accepted that chronic inflammation plays an active role in cancer. Inflammatory immunocytes and related cytokines in the tumor microenvironment are supposed to be a “double-edged sword” in colorectal cancer (CRC) initiation and progression. Interleukin-17 (IL-17), a pleiotropic proinflammatory cytokine, can promote cancer-elicited inflammation and prevent cancer cells from immune surveillance. Despite controversy, IL-17 is generally considered to be a promoter in CRC progression....

  16. Arsenic in private well water part 2 of 3: Who benefits the most from traditional testing promotion?

    Science.gov (United States)

    Flanagan, Sara V; Spayd, Steven E; Procopio, Nicholas A; Chillrud, Steven N; Ross, James; Braman, Stuart; Zheng, Yan

    2016-08-15

    Arsenic, a toxic element naturally found in groundwater, is a public health concern for households drinking from wells. Private well water is not regulated to meet the federal drinking water arsenic Maximum Contaminant Level (MCL) of 10μg/L, or the more protective 5μg/L New Jersey (NJ) state MCL. In the absence of consistent private well regulation, public health efforts have relied on promoting testing in affected communities to various degrees of success. Few interventions publish results, and more often focus on the outcome of tested wells rather than who completed a test, and more importantly, who did not. Through our survey of randomly selected addresses (n=670) in 17 NJ towns we find higher rates of arsenic testing in areas with a history of testing promotion. However, we also see a stronger correlation of testing behavior with income and education in high promotion areas, suggesting that community engagement activities may be exacerbating socioeconomic status (SES) testing disparities. Well owners with a bachelor's degree had ten times greater odds of participating in our direct mail testing intervention than those with less education when tests cost $40. After all households (n=255) were offered free tests to overcome many of the usual testing barriers - awareness, convenience, and cost - only 47% participated and those who chose to return water samples were of higher income and education than those who did not. Our findings highlight that while efforts to promote and provide arsenic testing succeed in testing more wells, community testing interventions risk increasing SES disparities if those with more education and resources are more likely to take advantage of testing programs. Therefore, testing interventions can benefit by better targeting socially vulnerable populations in an effort to overcome SES-patterned self-selection when individuals are left alone with the responsibility of managing their drinking water quality. PMID:27142115

  17. Alterations in HIV-1 LTR promoter activity during AIDS progression

    International Nuclear Information System (INIS)

    HIV-1 variants evolving in AIDS patients frequently show increased replicative capacity compared to those present during early asymptomatic infection. It is known that late stage HIV-1 variants often show an expanded coreceptor tropism and altered Nef function. In the present study we investigated whether enhanced HIV-1 LTR promoter activity might also evolve during disease progression. Our results demonstrate increased LTR promoter activity after AIDS progression in 3 of 12 HIV-1-infected individuals studied. Further analysis revealed that multiple alterations in the U3 core-enhancer and in the transactivation-response (TAR) region seem to be responsible for the enhanced functional activity. Our findings show that in a subset of HIV-1-infected individuals enhanced LTR transcription contributes to the increased replicative potential of late stage virus isolates and might accelerate disease progression

  18. RECENT PROGRESS IN ARSENIC RESEARCH IN CHINA%中国关于砷的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈保卫; Le X. Chris

    2011-01-01

    综述了近年来有关中国的砷污染状况、相关的分析监测技术及砷化合物毒性的研究进展.在中国部分地区,长期砷暴露导致了严重的区域性的砷中毒,主要的暴露途径是饮用水、食物和煤炭的燃烧.样品前处理、砷的富集和形态分析技术的丰富和发展,为环境科学、毒理学和流行病学的研究提供了可靠的技术支持.生物检测是一种直接有效的污染物健康风险评估方法,尿样、血液、唾液、头发和指甲中的砷及生理生化指标直接反映了暴露主体的砷暴露程度和砷相关的损伤程度.在砷的生物代谢过程中,产生活性氧和自由基,导致氧化应激的提高,影响亚铁血红蛋白的生物合成,导致细胞膜的过氧化,线粒体相关的细胞凋亡,DNA的氧化损伤而产生基因突变.砷中毒的易受程度,与年龄、营养状况、硒的摄入相关.砷化合物能穿过胎盘屏障影响胎儿的发育,穿过脑血屏障影响智力发育和导致神经毒性.慢性砷中毒的机理还有待进一步的研究.%This review summarizes recent research conducted on environmental arsenic in China,covering the topics of environmental contamination,human exposure,speciation analysis,biomonitoring,biotransformation,and toxicity of arsenic compounds.Chronic exposure to arsenic through ingestion of drinking water and contaminated food,and/or inhalation of contaminated air due to coal combustion is responsible for endemic arsenicosis in several areas of China.Progress has been made in analytical techniques for speciation analysis,increasing the number of studies on environmental chemistry,toxicology,and epidemiology of arsenic.Urine,blood,saliva,hair,and nail have been analyzed for arsenic species to assess arsenic exposure.Epidemiological,biochemical,and animal studies have linked excess arsenic exposure with the elevated levels of oxidation stress,as measured by oxidative damage to DNA and peroxidation of cell

  19. Hypothermia activates adipose tissue to promote malignant lung cancer progression.

    Directory of Open Access Journals (Sweden)

    Gangjun Du

    Full Text Available Microenvironment has been increasingly recognized as a critical regulator of cancer progression. In this study, we identified early changes in the microenvironment that contribute to malignant progression. Exposure of human bronchial epithelial cells (BEAS-2B to methylnitrosourea (MNU caused a reduction in cell toxicity and an increase in clonogenic capacity when the temperature was lowered from 37°C to 28°C. Hypothermia-incubated adipocyte media promoted proliferation in A549 cells. Although a hypothermic environment could increase urethane-induced tumor counts and Lewis lung cancer (LLC metastasis in lungs of three breeds of mice, an increase in tumor size could be discerned only in obese mice housed in hypothermia. Similarly, coinjections using differentiated adipocytes and A549 cells promoted tumor development in athymic nude mice when adipocytes were cultured at 28°C. Conversely, fat removal suppressed tumor growth in obese C57BL/6 mice inoculated with LLC cells. Further studies show hypothermia promotes a MNU-induced epithelial-mesenchymal transition (EMT and protects the tumor cell against immune control by TGF-β1 upregulation. We also found that activated adipocytes trigger tumor cell proliferation by increasing either TNF-α or VEGF levels. These results suggest that hypothermia activates adipocytes to stimulate tumor boost and play critical determinant roles in malignant progression.

  20. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC). Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131) using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041), increased lymph node metastasis (P = 0.001), less differentiation (P = 0.005), increased recurrence (P = 0.038) and shorter survival (P = 0.004) of the patients. In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and treatment of OSCC

  1. Morphine Promotes Tumor Angiogenesis and Increases Breast Cancer Progression

    Directory of Open Access Journals (Sweden)

    Sabrina Bimonte

    2015-01-01

    Full Text Available Morphine is considered a highly potent analgesic agent used to relieve suffering of patients with cancer. Several in vitro and in vivo studies showed that morphine also modulates angiogenesis and regulates tumour cell growth. Unfortunately, the results obtained by these studies are still contradictory. In order to better dissect the role of morphine in cancer cell growth and angiogenesis we performed in vitro studies on ER-negative human breast carcinoma cells, MDA.MB231 and in vivo studies on heterotopic mouse model of human triple negative breast cancer, TNBC. We demonstrated that morphine in vitro enhanced the proliferation and inhibited the apoptosis of MDA.MB231 cells. In vivo studies performed on xenograft mouse model of TNBC revealed that tumours of mice treated with morphine were larger than those observed in other groups. Moreover, morphine was able to enhance the neoangiogenesis. Our data showed that morphine at clinical relevant doses promotes angiogenesis and increases breast cancer progression.

  2. Cyr61 promotes breast tumorigenesis and cancer progression

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Miaw-Sheue; Bogart, Daphne F.; Castaneda, Jessica M.; Li, Patricia; Lupu, Ruth

    2002-01-16

    Cyr61, a member of the CCN family of genes, is an angiogenic factor. We have shown that it is overexpressed in invasive and metastatic human breast cancer cells and tissues. Here, we investigated whether Cyr61 is necessary and/or sufficient to bypass the ''normal'' estrogen (E2) requirements for breast cancer cell growth. Our results demonstrate that under E2-depleted condition, Cyr61 is sufficient to induce MCF-7 cells grow in the absence of E2. MCF-7 cells transfected with Cyr61 (MCF-7/Cyr61) became E2-independent but still E2-responsive. On the other hand, MCF-7/vector cells remain E2-dependent. MCF-7/Cyr61 cells acquire an antiestrogen-resistant phenotype, one of the most common clinical occurrences during breast cancer progression. MCF-7/Cyr61 cells are anchorage-independent and capable of forming Matrigel outgrowth patterns in the absence of E2. ERa expression in MCF-7/Cyr61 cells is decreased although still functional. Additionally, MCF-7/Cyr61 cells are tumorigenic in ovariectomized athymic nude mice. The tumors resemble human invasive carcinomas with increased vascularization and overexpression of vascular endothelial growth factor (VEGF). Our results demonstrate that Cyr61 is a tumor-promoting factor and a key regulator of breast cancer progression. This study provides evidence that Cyr61 is sufficient to induce E2-independence and anti-E2 resistance, and to promote invasiveness in vitro, and to induce tumorigenesis in vivo, all of which are characteristics of an aggressive breast cancer phenotype.

  3. Effect of arsenic on tolerance mechanisms of two plant growth-promoting bacteria used as biological inoculants.

    Science.gov (United States)

    Armendariz, Ana L; Talano, Melina A; Wevar Oller, Ana L; Medina, María I; Agostini, Elizabeth

    2015-07-01

    Bacterial ability to colonize the rhizosphere of plants in arsenic (As) contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria (PGPR) used as inoculants, since they can contribute to enhance plant As tolerance and limit metalloid uptake by plants. The aim of this work was to study the effect of As on growth, exopolysaccharide (EPS) production, biofilm formation and motility of two strains used as soybean inoculants, Bradyrhizobium japonicum E109 and Azospirillum brasilense Az39. The metabolism of arsenate (As(V)) and arsenite (As(III)) and their removal and/or possible accumulation were also evaluated. The behavior of both bacteria under As treatment was compared and discussed in relation to their potential for colonizing plant rhizosphere with high content of the metalloid. B. japonicum E109 growth was reduced with As(III) concentration from 10 μM while A. brasilense Az39 showed a reduction of growth with As(III) from 500 μM. EPS and biofilm production increased significantly under 25 μM As(III) for both strains. Moreover, this was more notorious for Azospirillum under 500 μM As(III), where motility was seriously affected. Both bacterial strains showed a similar ability to reduce As(V). However, Azospirillum was able to oxidize more As(III) (around 53%) than Bradyrhizobium (17%). In addition, both strains accumulated As in cell biomass. The behavior of Azospirillum under As treatments suggests that this strain would be able to colonize efficiently As contaminated soils. In this way, inoculation with A. brasilense Az39 would positively contribute to promoting growth of different plant species under As treatment. PMID:26141894

  4. Arsenic-induced promoter hypomethylation and over-expression of ERCC2 reduces DNA repair capacity in humans by non-disjunction of the ERCC2-Cdk7 complex.

    Science.gov (United States)

    Paul, Somnath; Banerjee, Nilanjana; Chatterjee, Aditi; Sau, Tanmoy J; Das, Jayanta K; Mishra, Prafulla K; Chakrabarti, Partha; Bandyopadhyay, Arun; Giri, Ashok K

    2014-04-01

    Arsenic in drinking water is of critical concern in West Bengal, India, as it results in several physiological symptoms including dermatological lesions and cancers. Impairment of the DNA repair mechanism has been associated with arsenic-induced genetic damage as well as with several cancers. ERCC2 (Excision Repair Cross-Complementing rodent repair, complementation group 2), mediates DNA-repair by interacting with Cdk-activating kinase (CAK) complex, which helps in DNA proof-reading during transcription. Arsenic metabolism alters epigenetic regulation; we tried to elucidate the regulation of ERCC2 in arsenic-exposed humans. Water, urine, nails, hair and blood samples from one hundred and fifty seven exposed and eighty eight unexposed individuals were collected. Dose dependent validation was done in vitro using HepG2 and HEK-293. Arsenic content in the biological samples was higher in the exposed individuals compared with the content in unexposed individuals (p < 0.001). Bisulfite-modified methylation specific PCR showed a significant (p < 0.0001) hypomethylation of the ERCC2 promoter in the arsenic-exposed individuals. Densitometric analysis of immunoblots showed a nearly two-fold increase in expression of ERCC2 in exposed individuals, but there was an enhanced genotoxic insult as measured by micronuclei frequency. Immuno-precipitation and western blotting revealed an increased (p < 0.001) association of Cdk7 with ERCC2 in highly arsenic exposed individuals. The decrease in CAK activity was determined by observing the intensity of Ser(392) phosphorylation in p53, in vitro, which decreased with an increase in arsenic dose. Thus we infer that arsenic biotransformation leads to promoter hypomethylation of ERCC2, which in turn inhibits the normal functioning of the CAK-complex, thus affecting DNA-repair; this effect was highest among the arsenic exposed individuals with dermatological lesions. PMID:24473091

  5. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective.

    Directory of Open Access Journals (Sweden)

    Silvia eLampis

    2015-02-01

    Full Text Available A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: i non-inoculated plants; ii plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A; iii plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4 and Pseudoxanthomonas sp. P4V6 (B, and iv plants inoculated with all five bacterial strains (AB. The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community.

  6. Research and application progress of MGMT promoter methylation in gliomas

    OpenAIRE

    Cui-yun SUN; Shi-zhu YU

    2014-01-01

    O6-methylguanine-DNA methyltransferase (MGMT) is an important DNA repair enzyme. The promoter methylation status of MGMT gene has recently become a biomarker of gliomas. Methylation of the MGMT promoter not only is an important biomarker to evaluate the sensitivity to the chemotherapy with alkylating agents, but also contributes to predicting prognosis and distinguishing between recurrence and pseudoprogression in glioma patients. Especially in the elderly, MGMT promoter methylation stat...

  7. Technology transfer: Promoting irrigation progress and best management practices

    Science.gov (United States)

    Educational efforts promoting irrigation best management practices are designed to increase adoption of these practices and increase public understanding of the importance of irrigation. They increase visibility and the impact of the Ogallala Aquifer Program and promote affiliated research and exten...

  8. Research and application progress of MGMT promoter methylation in gliomas

    Directory of Open Access Journals (Sweden)

    Cui-yun SUN

    2014-07-01

    Full Text Available O6-methylguanine-DNA methyltransferase (MGMT is an important DNA repair enzyme. The promoter methylation status of MGMT gene has recently become a biomarker of gliomas. Methylation of the MGMT promoter not only is an important biomarker to evaluate the sensitivity to the chemotherapy with alkylating agents, but also contributes to predicting prognosis and distinguishing between recurrence and pseudoprogression in glioma patients. Especially in the elderly, MGMT promoter methylation status has recently been introduced to be a biomarker for glioma classification and personalized treatment strategies. This review gives a short summary of the function of MGMT and clinical application of MGMT promoter methylation in personalized treatment strategies, prognosis evaluation and differentiation of recurrence and pseudoprogression of glioma. doi: 10.3969/j.issn.1672-6731.2014.07.017

  9. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Comprehensive progress report, October 1, 1975--December 31, 1978

    International Nuclear Information System (INIS)

    Investigations were undertaken to elucidate the mode of transepithelial transport of potentially toxic metal ions across the gastrointestinal tract, with primary attention given to cadmium, zinc, and arsenic. In addition, the toxic effects of cadmium on the metabolism of vitamin D and calcium have been investigated in some detail. Several approaches have been taken, including studies on the localization of heavy metals in the intestinal mucosa, the effects of cadmium on various parameters of calcium metabolism, the modes of intestinal absorption of cadmium, arsenate, and zinc, and the interactions of heavy metals with each other and with calcium, phosphorus, and vitamin D. Details of these experiments are attached in the Comprehensive Progress Report

  10. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Comprehensive progress report, October 1, 1975--December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, R. H.

    1978-10-01

    Investigations were undertaken to elucidate the mode of transepithelial transport of potentially toxic metal ions across the gastrointestinal tract, with primary attention given to cadmium, zinc, and arsenic. In addition, the toxic effects of cadmium on the metabolism of vitamin D and calcium have been investigated in some detail. Several approaches have been taken, including studies on the localization of heavy metals in the intestinal mucosa, the effects of cadmium on various parameters of calcium metabolism, the modes of intestinal absorption of cadmium, arsenate, and zinc, and the interactions of heavy metals with each other and with calcium, phosphorus, and vitamin D. Details of these experiments are attached in the Comprehensive Progress Report.

  11. TLR5 signaling, commensal microbiota and systemic tumor promoting inflammation: the three parcae of malignant progression

    Science.gov (United States)

    Rutkowski, Melanie R; Conejo-Garcia, Jose R

    2015-01-01

    We have reported that TLR5-mediated recognition of commensal microbiota modulates systemic tumor-promoting inflammation and malignant progression of tumors at distal locations. Approximately 7–10% of the general population harbors a deleterious single nucleotide polymorphism in TLR5, implicating a novel role for genetic variation during the initiation and progression of cancer. PMID:26405577

  12. Self-reported health promotion and disability progression in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, Marie Beatrice; Nagels, Guy; De Keyser, Jacques; Haentjens, Patrick

    2013-01-01

    Background: Health behavior may be associated with disability progression in multiple sclerosis (MS). Objectives: To investigate health-promoting behavior as measured by the Health-Promoting Lifestyle Profile II, which includes the subscales of health responsibility, physical activity, nutrition, sp

  13. Does monitoring goal progress promote goal attainment? A meta-analysis of the experimental evidence.

    Science.gov (United States)

    Harkin, Benjamin; Webb, Thomas L; Chang, Betty P I; Prestwich, Andrew; Conner, Mark; Kellar, Ian; Benn, Yael; Sheeran, Paschal

    2016-02-01

    Control theory and other frameworks for understanding self-regulation suggest that monitoring goal progress is a crucial process that intervenes between setting and attaining a goal, and helps to ensure that goals are translated into action. However, the impact of progress monitoring interventions on rates of behavioral performance and goal attainment has yet to be quantified. A systematic literature search identified 138 studies (N = 19,951) that randomly allocated participants to an intervention designed to promote monitoring of goal progress versus a control condition. All studies reported the effects of the treatment on (a) the frequency of progress monitoring and (b) subsequent goal attainment. A random effects model revealed that, on average, interventions were successful at increasing the frequency of monitoring goal progress (d+ = 1.98, 95% CI [1.71, 2.24]) and promoted goal attainment (d+ = 0.40, 95% CI [0.32, 0.48]). Furthermore, changes in the frequency of progress monitoring mediated the effect of the interventions on goal attainment. Moderation tests revealed that progress monitoring had larger effects on goal attainment when the outcomes were reported or made public, and when the information was physically recorded. Taken together, the findings suggest that monitoring goal progress is an effective self-regulation strategy, and that interventions that increase the frequency of progress monitoring are likely to promote behavior change. PMID:26479070

  14. Arsenicals produce stable progressive changes in DNA methylation patterns that are linked to malignant transformation of immortalized urothelial cells

    Czech Academy of Sciences Publication Activity Database

    Jensen, T.J.; Novák, Petr; Wnek, S.M.; Gandolfi, A.J.; Futscher, B. W.

    2009-01-01

    Roč. 241, č. 2 (2009), s. 221-229. ISSN 0041-008X Institutional research plan: CEZ:AV0Z50510513 Keywords : DNA methylation * Epigenetic * Arsenic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.359, year: 2009

  15. Collagen density promotes mammary tumor initiation and progression

    Directory of Open Access Journals (Sweden)

    Knittel Justin G

    2008-04-01

    Full Text Available Abstract Background Mammographically dense breast tissue is one of the greatest risk factors for developing breast carcinoma. Despite the strong clinical correlation, breast density has not been causally linked to tumorigenesis, largely because no animal model has existed for studying breast tissue density. Importantly, regions of high breast density are associated with increased stromal collagen. Thus, the influence of the extracellular matrix on breast carcinoma development and the underlying molecular mechanisms are not understood. Methods To study the effects of collagen density on mammary tumor formation and progression, we utilized a bi-transgenic tumor model with increased stromal collagen in mouse mammary tissue. Imaging of the tumors and tumor-stromal interface in live tumor tissue was performed with multiphoton laser-scanning microscopy to generate multiphoton excitation and spectrally resolved fluorescent lifetimes of endogenous fluorophores. Second harmonic generation was utilized to image stromal collagen. Results Herein we demonstrate that increased stromal collagen in mouse mammary tissue significantly increases tumor formation approximately three-fold (p p Conclusion This study provides the first data causally linking increased stromal collagen to mammary tumor formation and metastasis, and demonstrates that fundamental differences arise and persist in epithelial tumor cells that progressed within collagen-dense microenvironments. Furthermore, the imaging techniques and signature identified in this work may provide useful diagnostic tools to rapidly assess fresh tissue biopsies.

  16. Neuropilin-2 promotes melanoma growth and progression in vivo.

    Science.gov (United States)

    Moriarty, Whei F; Kim, Edward; Gerber, Stephanie A; Hammers, Hans; Alani, Rhoda M

    2016-08-01

    Tumor cell interactions with their microenvironment, and neighboring endothelial cells in particular, are critical for tumor cell survival and the metastatic process. Within the spectrum of tumors, melanomas are notorious for their ability to metastasize at a relatively early stage of development; however, little is known about the molecular pathways mediating this process. We recently performed a screen to assess critical mediators of melanoma metastasis by evaluating melanoma-endothelial cell communication. Neuropilin-2 (NRP2), a cell surface receptor involved in angiogenesis and axonal guidance, was found to be an important mediator of melanoma-endothelial cell cross-talk in these studies. Here we seek to further define the role of NRP2 in melanoma growth and progression. We use stable gene silencing of NRP2 in melanomas from varying stages of tumor progression to define the role of NRP2 in melanoma growth, migration, invasion, and metastasis. We found that NRP2 gene silencing in metastatic melanoma cell lines inhibited tumor cell growth in vitro; furthermore, knockdown of NRP2 expression in the metastatic melanoma cell line 1205Lu significantly inhibited in-vivo tumor growth and metastasis. We conclude that NRP2 plays an important role in mediating melanoma growth and metastasis and suggest that targeting this cell surface molecule may represent a significant therapeutic strategy for patients diagnosed with aggressive forms of melanoma. PMID:26881875

  17. Disruption of Histone Modification and CARM1 Recruitment by Arsenic Represses Transcription at Glucocorticoid Receptor-Regulated Promoters

    OpenAIRE

    Barr, Fiona D.; Krohmer, Lori J.; Hamilton, Joshua W.; Sheldon, Lynn A.

    2009-01-01

    Chronic exposure to inorganic arsenic (iAs) found in the environment is one of the most significant and widespread environmental health risks in the U.S. and throughout the world. It is associated with a broad range of health effects from cancer to diabetes as well as reproductive and developmental anomalies. This diversity of diseases can also result from disruption of metabolic and other cellular processes regulated by steroid hormone receptors via aberrant transcriptional regulation. Signi...

  18. Plan and Design Meticulously and Promoting Technical Progress

    Institute of Scientific and Technical Information of China (English)

    Miao Chengwu

    1994-01-01

    @@ Plan and design is the key link in captial construction, and the soul of engineering construction. China Petroleum Planning & Engineering Institute (CPPEI) is one of the main undertakers for planning and designing of petroleum industry,the only leading multi-functional institute with the first class design certificate. Now it has been an organization under the China National Petroleum Corporation(CNPC)for making development strategy planning, project evaluations and technical consulting, drawing up project development plan and providing technical recommendations. It can complete plan and design for the oil and gas field facilities, pipeline construction,petroleum relinery and petro-chemical industry engineering at home and abroad. It is also a center of servicing for new technical development and scientific research. Since CPPEI was established in 1978,it has meticulously conducted on planning and designing for the technical progress of petroleum engineering.

  19. FYN promotes breast cancer progression through epithelial-mesenchymal transition.

    Science.gov (United States)

    Xie, Ye-Gong; Yu, Yue; Hou, Li-Kun; Wang, Xin; Zhang, Bin; Cao, Xu-Chen

    2016-08-01

    FYN, one of the members of the Src family of kinases (SFKs), has been reported to be overexpressed in various types of cancers and correlated with cell motility and proliferation. However, the mechanism is still unclear. In the present study, we found that FYN was overexpressed in breast cancer and overexpression of FYN promoted cell proliferation, migration and invasion in the MCF10A cells, whereas depletion of FYN suppressed cell proliferation, migration and invasion in the MDA-MB-231 cells. Moreover, FYN upregulated the expression of mesenchymal markers and epithelial-mesenchymal transition (EMT)-related transcription factors, and downregulated the expression of epithelial markers, suggesting that FYN induces EMT in breast cancer cells. Furthermore, FYN was transcriptionally regulated by FOXO1 and mediated FGF2-induced EMT through both the PI3K/AKT and ERK/MAPK pathways. PMID:27349276

  20. Speciation and detection of arsenic in aqueous samples: A review of recent progress in non-atomic spectrometric methods

    International Nuclear Information System (INIS)

    Highlights: • Compilation of principal official documents and major review articles, including the toxicology and chemistry of As. • Review of non-atomic spectrometric methods for speciation and detection of arsenic in aqueous samples (2005–2013) of the performance of field-usable methods. - Abstract: Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been

  1. Adverse effect of the CCR5 promoter -2459A allele on HIV-1 disease progression

    DEFF Research Database (Denmark)

    Knudsen, T B; Kristiansen, T B; Katzenstein, T L; Eugen-Olsen, J

    2001-01-01

    /G transition that has been discovered recently, have also been shown to influence HIV progression. Since genetic linkages make these polymorphisms interdependent variables, the aim of the present study was to isolate and evaluate the effect on HIV disease progression for each of these mutations independently......HIV positive individuals heterozygous for a 32 basepair deletion in the CCR5 encoding gene (CCR5 Delta32) have a reduced number of CCR5 receptors on the cell surface and a slower progression towards AIDS and death. Other human polymorphisms, such as the CCR2 64I and the CCR5 promoter -2459 A....... Genotypes were determined in 119 individuals enrolled in the Copenhagen AIDS Cohort. When including the concurrent effects of the CCR5 Delta32 and CCR2 64I mutations, homozygous carriers of the CCR5 promoter -2459A allele had a significantly faster progression towards death than heterozygous A/G individuals...

  2. Biochar in Co-Contaminated Soil Manipulates Arsenic Solubility and Microbiological Community Structure, and Promotes Organochlorine Degradation

    OpenAIRE

    Gregory, Samuel J.; Anderson, Christopher W. N; Camps-Arbestain, Marta; Biggs, Patrick J.; Ganley, Austen R. D.; O’Sullivan, Justin M.; McManus, Michael T

    2015-01-01

    We examined the effect of biochar on the water-soluble arsenic (As) concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp) was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1). The isomers o...

  3. Biochar in co-contaminated soil manipulates arsenic solubility and microbiological community structure, and promotes organochlorine degradation.

    Science.gov (United States)

    Gregory, Samuel J; Anderson, Christopher W N; Camps-Arbestain, Marta; Biggs, Patrick J; Ganley, Austen R D; O'Sullivan, Justin M; McManus, Michael T

    2015-01-01

    We examined the effect of biochar on the water-soluble arsenic (As) concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp) was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1). The isomers of hexachlorocyclohexane (HCH) alpha-HCH and gamma-HCH (lindane), underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity) due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil. PMID:25923541

  4. Arsenic trioxide promotes mitochondrial DNA mutation and cell apoptosis in primary APL cells and NB4 cell line.

    Science.gov (United States)

    Meng, Ran; Zhou, Jin; Sui, Meng; Li, ZhiYong; Feng, GuoSheng; Yang, BaoFeng

    2010-01-01

    This study aimed to investigate the effects of arsenic trioxide (As(2)O(3)) on the mitochondrial DNA (mtDNA) of acute promyelocytic leukemia (APL) cells. The NB4 cell line was treated with 2.0 micromol/L As(2)O(3) in vitro, and the primary APL cells were treated with 2.0 micromol/L As(2)O(3) in vitro and 0.16 mg kg(-1) d(-1) As(2)O(3) in vivo. The mitochondrial DNA of all the cells above was amplified by PCR, directly sequenced and analyzed by Sequence Navigatore and Factura software. The apoptosis rates were assayed by flow cytometry. Mitochondrial DNA mutation in the D-loop region was found in NB4 and APL cells before As(2)O(3) use, but the mutation spots were remarkably increased after As(2)O(3) treatment, which was positively correlated to the rates of cellular apoptosis, the correlation coefficient: r (NB4-As2O3)=0.973818, and r (APL-As2O3)=0.934703. The mutation types include transition, transversion, codon insertion or deletion, and the mutation spots in all samples were not constant and regular. It is revealed that As(2)O(3) aggravates mtDNA mutation in the D-loop region of acute promyelocytic leukemia cells both in vitro and in vivo. Mitochondrial DNA might be one of the targets of As(2)O(3) in APL treatment. PMID:20596959

  5. Activated Cdc42-associated kinase Ack1 promotes prostate cancer progression via androgen receptor tyrosine phosphorylation

    OpenAIRE

    Mahajan, Nupam P.; Liu, Yuanbo; Majumder, Samarpan; Warren, Maria R.; Parker, Carol E.; Mohler, James L.; Earp, H. Shelton; Whang, Young E.

    2007-01-01

    Activation of the androgen receptor (AR) may play a role in androgen-independent progression of prostate cancer. Multiple mechanisms of AR activation, including stimulation by tyrosine kinases, have been postulated. We and others have recently shown involvement of activated Cdc42-associated tyrosine kinase Ack1 in advanced human prostate cancer. Here we provide the molecular basis for interplay between Ack1 and AR in prostate cancer cells. Activated Ack1 promoted androgen-independent growth o...

  6. The Giardia cell cycle progresses independently of the anaphase-promoting complex

    OpenAIRE

    Gourguechon, Stéphane; Holt, Liam J.; Cande, W. Zacheus

    2013-01-01

    Most cell cycle regulation research has been conducted in model organisms representing a very small part of the eukaryotic domain. The highly divergent human pathogen Giardia intestinalis is ideal for studying the conservation of eukaryotic pathways. Although Giardia has many cell cycle regulatory components, its genome lacks all anaphase-promoting complex (APC) components. In the present study, we show that a single mitotic cyclin in Giardia is essential for progression into mitosis. Strikin...

  7. Proinflammatory Cytokines in Prostate Cancer Development and Progression Promoted by High-Fat Diet

    Directory of Open Access Journals (Sweden)

    Hua Xu

    2015-01-01

    Full Text Available Background. We aimed to examine whether proinflammatory cytokines participated in prostate cancer (PCa development and progression promoted by high-fat diet (HFD. Methods. TRAMP (transgenic adenocarcinoma mouse prostate mice were randomly divided into two groups: normal diet group and HFD group. Mortality rate and tumor formation rate were examined. TRAMP mice were sacrificed and sampled on the 20th, 24th, and 28th week, respectively. Levels of proinflammatory cytokines, including IL-1α, IL-1β, IL-6, and TNF-α, were tested by FlowCytomix. Prostate tissue of TRAMP mice was used for histology study. Results. A total of 13 deaths of TRAMP mice were observed, among which 3 (8.33% were from the normal diet group and 10 (27.78% from the HFD group. The mortality rate of TRAMP mice from HFD group was significantly higher than that of normal diet group (P=0.032. Tumor formation rate at 20th week of age of HFD group was significantly higher than that of normal diet group (P=0.045. Proinflammatory cytokines levels, including IL-1α, IL-1β, IL-6, and TNF-α, were significantly higher in HFD TRAMP mice. Conclusions. HFD could promote TRAMP mouse PCa development and progression with elevated proinflammatory cytokines levels. Proinflammatory cytokines could contribute to PCa development and progression promoted by HFD.

  8. Linking Microbial Activity with Arsenic Fate during Cow Dung Disposal of Arsenic-Bearing Wastes

    Science.gov (United States)

    Clancy, T. M.; Reddy, R.; Tan, J.; Hayes, K. F.; Raskin, L.

    2014-12-01

    To address widespread arsenic contamination of drinking water sources numerous technologies have been developed to remove arsenic. All technologies result in the production of an arsenic-bearing waste that must be evaluated and disposed in a manner to limit the potential for environmental release and human exposure. One disposal option that is commonly recommended for areas without access to landfills is the mixing of arsenic-bearing wastes with cow dung. These recommendations are made based on the ability of microorganisms to create volatile arsenic species (including mono-, di-, and tri-methylarsine gases) to be diluted in the atmosphere. However, most studies of environmental microbial communities have found only a small fraction (wastes produced during drinking water treatment in West Bengal, India. Arsenic in gaseous, aqueous, and solid phases was measured. Consistent with previous reports, less than 0.02% of the total arsenic present was volatilized. A much higher amount (~5%) of the total arsenic was mobilized into the liquid phase. Through the application of molecular tools, including 16S rRNA sequencing and quantification of gene transcripts involved in methanogenesis, this study links microbial community activity with arsenic fate in potential disposal environments. These results illustrate that disposal of arsenic-bearing wastes by mixing with cow dung does not achieve its end goal of promoting arsenic volatilization but rather appears to increase arsenic mobilization in the aqueous phase, raising concerns with this approach.

  9. Biochar in co-contaminated soil manipulates arsenic solubility and microbiological community structure, and promotes organochlorine degradation.

    Directory of Open Access Journals (Sweden)

    Samuel J Gregory

    Full Text Available We examined the effect of biochar on the water-soluble arsenic (As concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1. The isomers of hexachlorocyclohexane (HCH alpha-HCH and gamma-HCH (lindane, underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P < 0.01, and increased the DDE:DDT ratio. Soil microbial activity was significantly increased (P < 0.01 under all biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil.

  10. Arsenic Induced Phytate Exudation, and Promoted FeAsO4 Dissolution and Plant Growth in As-Hyperaccumulator Pteris vittata.

    Science.gov (United States)

    Liu, Xue; Fu, Jing-Wei; Guan, Dong-Xing; Cao, Yue; Luo, Jun; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2016-09-01

    Arsenic hyperaccumulator Pteris vittata (PV) is efficient in taking up As and nutrients from As-contaminated soils. We evaluated the mechanisms used by PV to mobilize As and Fe by examining the impacts of As and root exudates on FeAsO4 solubilization, and As and Fe uptake in four plants: As-hyperaccumulators PV and Pteris multifida (PM), nonhyperaccumulator Pteris ensiformis (PE), and angiosperm plant tomato (Solanum lycopersicum). Phytate and oxalate were dominant in fern plants (>93%), which were 50-83, 15-42, and 0-32 mg kg(-1) phytate and 10-15, 7-26, and 4-12 mg kg(-1) oxalate for PV, PM, and PE respectively, with higher As inducing greater phytate exudation and no phytate being detected in tomato exudates. PV treated with phytate+FeAsO4 had higher As and Fe contents and larger biomass than phytate or FeAsO4 treatment, which were 340 vs 20 and 130 mg kg(-1) As in the fronds and 7900 vs 1600 and 4100 mg kg(-1) Fe in the roots. We hypothesized that As-induced phytate exudation helped PV to take up Fe and As from insoluble FeAsO4 and promoted PV growth. Our study suggests that phytate exudation may be special to fern plants, which may play an important role in enhancing As and nutrient uptake by plants, thereby increasing their efficiency in phytoremediation of As-contaminated soils. PMID:27483027

  11. PIAS1-FAK Interaction Promotes the Survival and Progression of Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Jerfiz D. Constanzo

    2016-05-01

    Full Text Available The sequence of genomic alterations acquired by cancer cells during tumor progression and metastasis is poorly understood. Focal adhesion kinase (FAK is a non-receptor tyrosine kinase that integrates cytoskeleton remodeling, mitogenic signaling and cell survival. FAK has previously been reported to undergo nuclear localization during cell migration, cell differentiation and apoptosis. However, the mechanism behind FAK nuclear accumulation and its contribution to tumor progression has remained elusive. We report that amplification of FAK and the SUMO E3 ligase PIAS1 gene loci frequently co-occur in non-small cell lung cancer (NSCLC cells, and that both gene products are enriched in a subset of primary NSCLCs. We demonstrate that endogenous FAK and PIAS1 proteins interact in the cytoplasm and the cell nucleus of NSCLC cells. Ectopic expression of PIAS1 promotes proteolytic cleavage of the FAK C-terminus, focal adhesion maturation and FAK nuclear localization. Silencing of PIAS1 deregulates focal adhesion turnover, increases susceptibility to apoptosis in vitro and impairs tumor xenograft formation in vivo. Nuclear FAK in turn stimulates gene transcription favoring DNA repair, cell metabolism and cytoskeleton regulation. Consistently, ablation of FAK by CRISPR/Cas9 editing, results in basal DNA damage, susceptibility to ionizing radiation and impaired oxidative phosphorylation. Our findings provide insight into a mechanism regulating FAK cytoplasm-nuclear distribution and demonstrate that FAK activity in the nucleus promotes NSCLC survival and progression by increasing cell-ECM interaction and DNA repair regulation.

  12. Association Study between Promoter Polymorphism of TPH1 and Progression of Idiopathic Scoliosis

    Science.gov (United States)

    Yablanski, Vasil; Nikolova, Svetla; Vlaev, Evgeni; Savov, Alexey; Kremensky, Ivo

    2016-01-01

    The concept of disease-modifier genes as an element of genetic heterogeneity has been widely accepted and reported. The aim of the current study is to investigate the association between the promoter polymorphism TPH1 (rs10488682) and progression of idiopathic scoliosis (IS) in Eastern European population sample. A total of 105 patients and 210 healthy gender-matched controls were enrolled in this study. The TPH1 promoter polymorphism was genotyped by amplification followed by restriction. The statistical analysis was performed by Fisher's Exact Test. The results indicated that the genotypes and alleles of TPH1 (rs10488682) are not correlated with curve severity, curve pattern, or bracing. Therefore, the examined polymorphic variant could not be considered as a genetic factor with modifying effect of IS. In conclusion, this case-control study revealed no statistically significant association between TPH1 (rs10488682) and progression of IS in Eastern European population sample. These preliminary results should be replicated in extended population studies including larger sample sizes. The identification of molecular markers for IS could be useful for a more accurate prognosis of the risk for a rapid progression of the curve. That would permit early stage treatment of the patient with the least invasive procedures. PMID:27293961

  13. Arsenic transformation and plant growth promotion characteristics of As-resistant endophytic bacteria from As-hyperaccumulator Pteris vittata.

    Science.gov (United States)

    Xu, Jia-Yi; Han, Yong-He; Chen, Yanshan; Zhu, Ling-Jia; Ma, Lena Q

    2016-02-01

    The ability of As-resistant endophytic bacteria in As transformation and plant growth promotion was determined. The endophytes were isolated from As-hyperaccumulator Pteris vittata (PV) after growing for 60 d in a soil containing 200 mg kg(-1) arsenate (AsV). They were isolated in presence of 10 mM AsV from PV roots, stems, and leaflets, representing 4 phyla and 17 genera. All endophytes showed at least one plant growth promoting characteristics including IAA synthesis, siderophore production and P solubilization. The root endophytes had higher P solubilization ability than the leaflet (60.0 vs. 18.3 mg L(-1)). In presence of 10 mM AsV, 6 endophytes had greater growth than the control, suggesting As-stimulated growth. Furthermore, root endophytes were more resistant to AsV while the leaflet endophytes were more tolerant to arsenite (AsIII), which corresponded to the dominant As species in PV tissues. Bacterial As resistance was positively correlated to their ability in AsV reduction but not AsIII oxidation. The roles of those endophytes in promoting plant growth and As resistance in P. vittata warrant further investigation. PMID:26469935

  14. [Initiation, promotion, initiation experiments with radon and cigarette smoke: Lung tumors in rats]. Progress report

    International Nuclear Information System (INIS)

    During the past several years, the authors have made considerable progress in modeling carcinogenesis in general, and in modeling radiation carcinogenesis, in particular. They present an overview of their progress in developing stochastic carcinogenesis models and applying them to experimental and epidemiologic data sets. Traditionally, cancer models have been used for the analysis of incidence (or prevalence) data in epidemiology and time to tumor data in experimental studies. The relevant quantities for the analysis of these data are the hazard function and the probability of tumor. The derivation of these quantities is briefly described here. More recently, the authors began to use these models for the analysis of data on intermediate lesions on the pathway to cancer. Such data are available in experimental carcinogenesis studies, in particular in initiation and promotion studies on the mouse skin and the rat liver. If however, quantitative information on intermediate lesions on the pathway to lung cancer were to be come available at some future date, the methods that they have developed for the analysis of initiation-promotion experiments could easily be applied to the analysis of these lesions. The mathematical derivations here are couched in terms of a particular two-mutation model of carcinogenesis. Extension to models postulating more than two mutations is not always straightforward

  15. Neutrophil Extracellular Traps Promote the Development and Progression of Liver Metastases after Surgical Stress.

    Science.gov (United States)

    Tohme, Samer; Yazdani, Hamza O; Al-Khafaji, Ahmed B; Chidi, Alexis P; Loughran, Patricia; Mowen, Kerri; Wang, Yanming; Simmons, Richard L; Huang, Hai; Tsung, Allan

    2016-03-15

    Risks of tumor recurrence after surgical resection have been known for decades, but the mechanisms underlying treatment failures remain poorly understood. Neutrophils, first-line responders after surgical stress, may play an important role in linking inflammation to cancer progression. In response to stress, neutrophils can expel their protein-studded chromatin to form local snares known as neutrophil extracellular traps (NET). In this study, we asked whether, as a result of its ability to ensnare moving cells, NET formation might promote metastasis after surgical stress. Consistent with this hypothesis, in a cohort of patients undergoing attempted curative liver resection for metastatic colorectal cancer, we observed that increased postoperative NET formation was associated with a >4-fold reduction in disease-free survival. In like manner, in a murine model of surgical stress employing liver ischemia-reperfusion, we observed an increase in NET formation that correlated with an accelerated development and progression of metastatic disease. These effects were abrogated by inhibiting NET formation in mice through either local treatment with DNAse or inhibition of the enzyme peptidylarginine deaminase, which is essential for NET formation. In growing metastatic tumors, we found that intratumoral hypoxia accentuated NET formation. Mechanistic investigations in vitro indicated that mouse neutrophil-derived NET triggered HMGB1 release and activated TLR9-dependent pathways in cancer cells to promote their adhesion, proliferation, migration, and invasion. Taken together, our findings implicate NET in the development of liver metastases after surgical stress, suggesting that their elimination may reduce risks of tumor relapse. PMID:26759232

  16. DNAJC6 promotes hepatocellular carcinoma progression through induction of epithelial–mesenchymal transition

    International Nuclear Information System (INIS)

    Highlights: • DNAJC6 is up-regulated in hepatocellular carcinoma tissues. • DNAJC6 promotes hepatocellular carcinoma cell proliferation and invasion. • DNAJC6 induces epithelial–mesenchymal transition by activating transforming growth factor β signaling. - Abstract: Epithelial–mesenchymal transition (EMT) is a developmental program, which is associated with hepatocellular carcinoma (HCC) development and progression. DNAJC6 (DNA/HSP40 homolog subfamily C member 6) encodes auxilin, which is responsible for juvenile Parkinsonism with phenotypic variability. However, the role of DNAJC6 in HCC development and progression is limited. Here, we report that DNAJC6 is up-regulated in HCC tissues and up-regulation of DNAJC6 expression predicts poor outcome in patients with HCC. Furthermore, overexpression of DNAJC6 enhances the ability for acquisition of mesenchymal traits, enhanced cell proliferation and invasion. DNAJC6 positively regulated expression of EMT-related transcription factor, also activating transforming growth factor β (TGF-β) pathway to contribute to EMT. Our findings demonstrated an important function of DNAJC6 in the progression of HCC by induction of EMT, and they implicate DNAJC6 as a marker of poor outcome in HCC

  17. Beyond a tumor suppressor: Soluble E-cadherin promotes the progression of cancer.

    Science.gov (United States)

    Hu, Qi-Ping; Kuang, Jing-Ya; Yang, Qing-Kai; Bian, Xiu-Wu; Yu, Shi-Cang

    2016-06-15

    E-cadherin (E-cad) plays important roles in tumorigenesis as well as in tumor progression, invasion and metastasis. This protein exists in two forms: a membrane-tethered form and a soluble form. Full-length E-cad is membrane tethered. As a type I transmembrane glycoprotein, E-cad mainly mediates adherens junctions between cells and is involved in maintaining the normal structure of epithelial tissues. Soluble E-cad (sE-cad) is the extracellular fragment of the protein that is cleaved from the membrane after proteolysis of full-length E-cad. The production of sE-cad undermines adherens junctions, causing a reduction in cell aggregation capacity; furthermore, sE-cad can diffuse into the extracellular environment and the blood. As a paracrine/autocrine signaling molecule, sE-cad activates or inhibits multiple signaling pathways and participates in the progression of various types of cancer, such as breast cancer, ovarian cancer, and lung cancer, by promoting invasion and metastasis. This article briefly reviews the role of sE-cad in tumorigenesis and tumor progression and its significance in clinical therapeutics. PMID:26704932

  18. Wnt/β-catenin signaling regulated SATB1 promotes colorectal cancer tumorigenesis and progression.

    Science.gov (United States)

    Mir, R; Pradhan, S J; Patil, P; Mulherkar, R; Galande, S

    2016-03-31

    The chromatin organizer SATB1 has been implicated in the development and progression of multiple cancers including breast and colorectal cancers. However, the regulation and role of SATB1 in colorectal cancers is poorly understood. Here, we demonstrate that expression of SATB1 is induced upon hyperactivation of Wnt/β-catenin signaling and repressed upon depletion of TCF7L2 (TCF4) and β-catenin. Using several colorectal cancer cell line models and the APC min mutant zebrafish in vivo model, we established that SATB1 is a novel target of Wnt/β-catenin signaling. We show that direct binding of TCF7L2/β-catenin complex on Satb1 promoter is required for the regulation of SATB1. Moreover, SATB1 is sufficient to regulate the expression of β-catenin, members of TCF family, multiple downstream effectors and mediators of Wnt pathway. SATB1 potentiates the cellular changes and expression of key cancer-associated genes in non-aggressive colorectal cells, promotes their aggressive phenotype and tumorigenesis in vivo. Conversely, depletion of SATB1 from aggressive cells reprograms the expression of cancer-associated genes, reverses their cancer phenotype and reduces the potential of these cells to develop tumors in vivo. We also show that SATB1 and β-catenin bind to the promoters of TCF7L2 and the downstream targets of Wnt signaling and regulate their expression. Our findings suggest that SATB1 shares a feedback regulatory network with TCF7L2/β-catenin signaling and is required for Wnt signaling-dependent regulation of β-catenin. Collectively, these results provide unequivocal evidence to establish that SATB1 reprograms the expression of tumor growth- and metastasis-associated genes to promote tumorigenesis and functionally overlaps with Wnt signaling critical for colorectal cancer tumorigenesis. PMID:26165840

  19. Study on Causes of Slow Progress in Promoting the Application of Food Traceability System in China

    Institute of Scientific and Technical Information of China (English)

    Pinghua; HE; Peisi; CHEN

    2014-01-01

    Chinese government has attempted to promote food traceability system with all strength,but the application process of this system is very slow. The reason is that the adopters have a low level of system application,which causes the system to be invalid at the source of traceability. This paper applies literature research method to analyze the influencing factors for slow application process of the food traceability system in China from various angles including manufacturer,technology,consumer and law,and further concludes that the applying intention of manufacturers,cognizing and purchasing intentions of consumers,and legal environment are important factors for slow progress of system application. On the basis of the research conclusions,the paper proposes practical ways for better construction of food traceability system in China.

  20. Host Plasminogen Activator Inhibitor-1 Promotes Human Skin Carcinoma Progression in a Stage-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Catherine Maillard

    2005-01-01

    Full Text Available Angiogenesis and tumor expansion are associated with extracellular matrix remodeling and involve various proteases such as the plasminogen (Pig/plasminogen activator (PA system. Recently, several experimental data have implicated the plasminogen activator inhibitor-1 (PAI-1 in tumor angiogenesis in murine systems. However, little is known about PAI-1 functions in human skin carcinoma progression. By generating immunodeficient mice (in Rag-1-/- or nude background deleted for PAI-1 gene (PAI-1-/- , we have evaluated the impact of host PAI-1 deficiency on the tumorigenicity of two malignant human skin keratinocyte cell lines HaCaT II-4 and HaCaT A5-RT3 forming low-grade and high-grade carcinomas, respectively. When using the surface transplantation model, angiogenesis and tumor invasion of these two cell lines are strongly reduced in PAI-1-deficient mice as compared to the wild-type control animals. After subcutaneous injection in PAI-1-/- mice, the tumor incidence is reduced for HaCaT II-4 cells, but not for those formed by HaCaT A5-RT3 cells. These data indicate that PAI-1 produced by host cells is an important contributor to earlier stages of human skin carcinoma progression. It exerts its tumor-promoting effect in a tumor stage-dependent manner, but PAI-1 deficiency is not sufficient to prevent neoplastic growth of aggressive tumors of the human skin.

  1. Factors that promote Progression in Schools Functioning as Professional Learning Community

    Directory of Open Access Journals (Sweden)

    Martine Leclerc

    2012-12-01

    Full Text Available The purpose of this research is to identify factors that influence the functioning of a school working as a Professional Learning Community (PLC and to analyze the links between these factors and the school’s progression. This research was developed within the context of an interpretative research paradigm. The primary data collection tool employed is a one-hour semistructured interview with each participant, thus allowing researchers to identify each participating school’s level of development as a PLC and clarify the underlying factors that have a positive effect on this type of functioning. The interview plan, composed of themes relevant to this research project, is structured according to the Seidman model (1998. The schools were classified according to the three stages of development identified in the Professional Learning Communities Observation Grid (PLCOG from Leclerc, Moreau and Lépine (2009a, namely the initiation, implementation, and integration stages, using the seven indicators found in the professional literature. This study suggests certain dominant factors, particularly for schools in the initiation and integration stages. Recommendations are presented to better assist school administrators in supporting their teaching staff as a PLC.Leclerc, M., Moreau, A., Dumouchel, C., & Sallafranque-St-Louis, F. (2012. Factors that promote Progression in Schools Functioning as Professional Learning Community. International Journal of Education Policy and Leadership 7(7. Retrieved from www.ijepl.org.

  2. The Placental Gene PEG10 Promotes Progression of Neuroendocrine Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Shusuke Akamatsu

    2015-08-01

    Full Text Available More potent targeting of the androgen receptor (AR in advanced prostate cancer is driving an increased incidence of neuroendocrine prostate cancer (NEPC, an aggressive and treatment-resistant AR-negative variant. Its molecular pathogenesis remains poorly understood but appears to require TP53 and RB1 aberration. We modeled the development of NEPC from conventional prostatic adenocarcinoma using a patient-derived xenograft and found that the placental gene PEG10 is de-repressed during the adaptive response to AR interference and subsequently highly upregulated in clinical NEPC. We found that the AR and the E2F/RB pathway dynamically regulate distinct post-transcriptional and post-translational isoforms of PEG10 at distinct stages of NEPC development. In vitro, PEG10 promoted cell-cycle progression from G0/G1 in the context of TP53 loss and regulated Snail expression via TGF-β signaling to promote invasion. Taken together, these findings show the mechanistic relevance of RB1 and TP53 loss in NEPC and suggest PEG10 as a NEPC-specific target.

  3. PCAF-primed EZH2 acetylation regulates its stability and promotes lung adenocarcinoma progression

    Institute of Scientific and Technical Information of China (English)

    Wan Junhu; Chin Y Eugene; Zhang Hongquan; Zhan Jun; Li Shuai; Ma Ji; Xu Weizhi; Liu Chang; Xue Xiaowei; Xie Yuping; Fang Weigang

    2015-01-01

    Enhancer of zeste homolog 2 ( EZH2 ) is a key epigenetic regulator that catalyzes the trimethyla-tion of H3K27 and is modulated by post-translational modifications (PTMs). However, the precise regulation of EZH2 PTMs remains elusive. We, herein, report that EZH2 is acetylated by acetyltransferase P300/CBP-associat-ed factor (PCAF) and is deacetylated by deacetylase SIRT1. We identified that PCAF interacts with and acetylates EZH2 mainly at lysine 348 (K348). Mechanistically, K348 acetylation decreases EZH2 phosphorylation at T345 and T487 and increases EZH2 stability without disrupting the formation of polycomb repressive complex 2 ( PRC2 ) . Functionally, EZH2 K348 acetylation enhances its capacity in suppression of the target genes and promotes lung cancer cell migration and invasion. Further, elevated EZH2 K348 acetylation in lung adenocarcinoma patients pre-dicts a poor prognosis. Our findings define a new mechanism underlying EZH2 modulation by linking EZH2 acety-lation to its phosphorylation that stabilizes EZH2 and promotes lung adenocarcinoma progression.

  4. Neural protein gamma-synuclein interacting with androgen receptor promotes human prostate cancer progression

    International Nuclear Information System (INIS)

    Gamma-synuclein (SNCG) has previously been demonstrated to be significantly correlated with metastatic malignancies; however, in-depth investigation of SNCG in prostate cancer is still lacking. In the present study, we evaluated the role of SNCG in prostate cancer progression and explored the underlying mechanisms. First, alteration of SNCG expression in LNCaP cell line to test the ability of SNCG on cellular properties in vitro and vivo whenever exposing with androgen or not. Subsequently, the Dual-luciferase reporter assays were performed to evaluate whether the role of SNCG in LNCaP is through AR signaling. Last, the association between SNCG and prostate cancer progression was assessed immunohistochemically using a series of human prostate tissues. Silencing SNCG by siRNA in LNCaP cells contributes to the inhibition of cellular proliferation, the induction of cell-cycle arrest at the G1 phase, the suppression of cellular migration and invasion in vitro, as well as the decrease of tumor growth in vivo with the notable exception of castrated mice. Subsequently, mechanistic studies indicated that SNCG is a novel androgen receptor (AR) coactivator. It interacts with AR and promotes prostate cancer cellular growth and proliferation by activating AR transcription in an androgen-dependent manner. Finally, immunohistochemical analysis revealed that SNCG was almost undetectable in benign or androgen-independent tissues prostate lesions. The high expression of SNCG is correlated with peripheral and lymph node invasion. Our data suggest that SNCG may serve as a biomarker for predicting human prostate cancer progression and metastasis. It also may become as a novel target for biomedical therapy in advanced prostate cancer

  5. Neurotensin promotes the progression of malignant glioma through NTSR1 and impacts the prognosis of glioma patients

    OpenAIRE

    Ouyang, Qing; Gong, Xueyang; Xiao, Hualiang; Zhou, Ji; Xu, Minhui; Dai, Yun; Xu, Lunshan; Feng, Hua; Cui, Hongjuan; Yi, Liang

    2015-01-01

    Background The poor prognosis and minimally successful treatments of malignant glioma indicate a challenge to identify new therapeutic targets which impact glioma progression. Neurotensin (NTS) and its high affinity receptor (NTSR1) overexpression induces neoplastic growth and predicts the poor prognosis in various malignancies. Whether NTS can promote the glioma progression and its prognostic significance for glioma patients remains unclear. Methods NTS precursor (ProNTS), NTS and NTSR1 expr...

  6. A Study on Promotion and Implementation of Cleaner Production Practices in Malaysian Industry - Development of a National Program and Action Plan for Promotion of Cleaner Production. Progress Report 1

    DEFF Research Database (Denmark)

    Wangel, Arne

    This Progress Report presents the initial findings of the research project 'A Study on Promotion and Implementation of Cleaner Production Practices in Malaysian Industry - Development of a National Program and Action Plan for Promotion of Cleaner Production. Progress Report' funded by the Departm......This Progress Report presents the initial findings of the research project 'A Study on Promotion and Implementation of Cleaner Production Practices in Malaysian Industry - Development of a National Program and Action Plan for Promotion of Cleaner Production. Progress Report' funded...

  7. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-05-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice.

  8. Earth Abides Arsenic Biotransformations

    OpenAIRE

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology ...

  9. Cryptic exposure to arsenic

    OpenAIRE

    Rossy Kathleen; Janusz Christopher; Schwartz Robert

    2005-01-01

    Arsenic is an odorless, colorless and tasteless element long linked with effects on the skin and viscera. Exposure to it may be cryptic. Although human intake can occur from four forms, elemental, inorganic (trivalent and pentavalent arsenic) and organic arsenic, the trivalent inorganic arsenicals constitute the major human hazard. Arsenic usually reaches the skin from occupational, therapeutic, or environmental exposure, although it still may be employed as a poison. Occupations involving ne...

  10. Progress in Japanese uranium enrichment technology and the promotion of industrialization

    International Nuclear Information System (INIS)

    The development of uranium enrichment technology with centrifuges, undertaken as a national project, has reached the stage that the pilot plant built by the Power Reactor and Nuclear Fuel Development Corporation will start the partial operation around the middle of this year. In order to assure the constant supply of nuclear fuel to Japan, it is necessary to establish an independent nuclear fuel cycle, and for the purpose, uranium enrichment must be industrialized by the use of Japanese own technology, because for the time being, light water reactors will be mainly employed. The Uranium Enrichment Evaluation Subcommittee was set up in July, 1978, and began the studies by evaluating the progress made in the development of centrifugal enrichment techniques by the PNC. The goal of development is changing from the technical improvement of centrifuges themselves to the economic performance. The facilities for the conversion of feed uranium into UF6, the blending and storage of enriched uranium, and the enrichment proper including centrifuge production were studied, and the existing fundamental technologies in Japan can solve the problems without much difficulty. The results of evaluation of the enrichment technology, the urgent need for uranium enrichment in Japan, and the measures to promote the industrialization are explained. (Kako, I.)

  11. Genistein increases epidermal growth factor receptor signaling and promotes tumor progression in advanced human prostate cancer.

    Directory of Open Access Journals (Sweden)

    Hisae Nakamura

    Full Text Available Genistein is an isoflavone found in soy, and its chemo-preventive and -therapeutic effects have been well established from in vitro studies. Recently, however, its therapeutic actions in vivo have been questioned due to contradictory reports from animal studies, which rely on rodent models or implantation of cell lines into animals. To clarify in vivo effects of genistein in advanced prostate cancer patients, we developed a patient-derived prostate cancer xenograft model, in which a clinical prostatectomy sample was grafted into immune deficient mice. Our results showed an increased lymph node (LN and secondary organ metastases in genistein-treated mice compared to untreated controls. Interestingly, invasive malignant cells aggregated to form islands/micrometastasis only in the secondary organs of the genistein-treated groups, not in the untreated control group. To understand the underlying mechanism for metastatic progression, we examined cell proliferation and apoptosis on paraffin-sections. Immunohistological data show that tumors of genistein-treated groups have more proliferating and fewer apoptotic cancer cells than those of the untreated group. Our immunoblotting data suggest that increased proliferation and metastasis are linked to enhanced activities of tyrosine kinases, EGFR and its downstream Src, in genistein-treated groups. Despite the chemopreventive effects proposed by earlier in vitro studies, the cancer promoting effect of genistein observed here suggests the need for careful selection of patients and safer planning of clinical trials.

  12. FoxD3 deficiency promotes breast cancer progression by induction of epithelial–mesenchymal transition

    International Nuclear Information System (INIS)

    Highlights: • FOXD3 is down-regulated in breast cancer tissues. • FOXD3 inhibits breast cancer cell proliferation and invasion. • FoxD3 deficiency induces epithelial–mesenchymal transition. - Abstract: The transcription factor forkhead box D3 (FOXD3) plays an important role in the development of neural crest and gastric cancer cells. However, the function and mechanisms of FOXD3 in the breast tumorigenesis and progression is still limited. Here, we report that FOXD3 is a tumor suppressor of breast cancer tumorigenicity and aggressiveness. We found that FOXD3 is down-regulated in breast cancer tissues. Patients with low FOXD3 expression have a poor outcome. Depletion of FOXD3 expression promotes breast cancer cell proliferation and invasion in vitro, whereas overexpression of FOXD3 inhibits breast cancer cell proliferation and invasion both in vitro and in vivo. In addition, depletion of FOXD3 is linked to epithelial–mesenchymal transition (EMT)-like phenotype. Our results indicate FOXD3 exhibits tumor suppressive activity and may be useful for breast therapy

  13. Promotion

    OpenAIRE

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed.

  14. Massive acute arsenic poisonings.

    Science.gov (United States)

    Lech, Teresa; Trela, Franciszek

    2005-07-16

    Arsenic poisonings are still important in the field of toxicology, though they are not as frequent as about 20-30 years ago. In this paper, the arsenic concentrations in ante- and post-mortem materials, and also forensic and anatomo-pathological aspects in three cases of massive acute poisoning with arsenic(III) oxide (two of them with unexplained criminalistic background, in which arsenic was taken for amphetamine and one suicide), are presented. Ante-mortem blood and urine arsenic concentrations ranged from 2.3 to 6.7 microg/ml, respectively. Post-mortem tissue total arsenic concentrations were also detected in large concentrations. In case 3, the contents of the duodenum contained as much as 30.1% arsenic(III) oxide. The high concentrations of arsenic detected in blood and tissues in all presented cases are particularly noteworthy in that they are very rarely detected at these concentrations in fatal arsenic poisonings. PMID:15939162

  15. Research Progress in the Speciation of Arsenic with Hyphenated Techniques%联用技术在砷形态分析中的研究进展

    Institute of Scientific and Technical Information of China (English)

    李林林; 朱英存

    2013-01-01

    Currently the main analysis techniques for arsenic speciation were the combination of chromatograph with atomic spectrum and mass spectrum, especially the combination of HPLC with ICP-OES or ICP-MS. The methods were accurate and reliable and had high sensitivity. But they can not provide the structural information of arsenic compounds. So the combination of chromatograph with ESI-MS was used as the main method for qualitative analysis. The insufficient sensitivity and vulnerability to matrix interference of ESI-MS can be overcome by the complex pretreatment technique. In this article hyphenated techniques were evaluated with particular emphasis on interfaced separation with element-selective detection and identification of the arsenic compounds detected.%  目前用元素砷的形态分析技术主要是色谱与子光谱、质谱等的联用,最常用的是HPLC与ICP-OES、 ICP-MS的联用,方法准确可靠,灵敏度高,但是不能提供砷化合物的分子结构信息。此以色谱-电喷雾质谱(ESI-MS)的联用作为定性分析的主要手段,但是ESI-MS灵敏度低,易受基体干扰,此需要复杂的前处理技术。

  16. Daily goal progress is facilitated by spousal support and promotes psychological, physical, and relational well-being throughout adulthood.

    Science.gov (United States)

    Jakubiak, Brittany K; Feeney, Brooke C

    2016-09-01

    In 2 daily diary studies, we tested the consequences and precursors of daily goal progress throughout the adult life span. Attachment theory posits that exploration-including the pursuit of autonomous goals-promotes well-being across the life span and is facilitated by support from close others. For both young-adult newlyweds (Study 1) and married couples in late adulthood (Study 2), daily independent goal progress predicted same-day and next-day improvements in psychological, physical, and relational well-being. Specifically, when participants made more progress on their goals than usual on one day, they reported increases in positive affect, sleep quality, and relationship quality, and decreased physical symptoms, the following day (as well as concurrently). Additionally, spousal support (i.e., availability, encouragement, and noninterference) enabled same-day and next-day goal progress. Mediational analyses showed indirect links between spousal support and well-being through goal progress. Some effects were moderated by attachment orientation in the newlywed sample; individuals with greater insecure attachment benefited most from goal progress, and spousal support enabled goal progress most strongly for individuals with less anxious attachment. Overall, these results support and extend attachment theoretical propositions regarding the importance of the exploration system across the adult life span. They contribute to existing literature by demonstrating wide-ranging consequences of successful exploration for well-being and by providing evidence for the importance of both exploration and support for exploration into late adulthood. (PsycINFO Database Record PMID:27560610

  17. Postmenopausal obesity promotes tumor angiogenesis and breast cancer progression in mice.

    Science.gov (United States)

    Gu, Jian-Wei; Young, Emily; Patterson, Sharla G; Makey, Kristina L; Wells, Jeremy; Huang, Min; Tucker, Kevan B; Miele, Lucio

    2011-05-15

    Obese postmenopausal women have a 50% higher risk of breast cancer than non-obese women. There is not an animal model that mimics postmenopausal obesity related to breast cancer progression. Using age-relevant C57BL/6 mice, this study determined whether postmenopausal obesity increases VEGF expression, tumor angiogenesis, and breast tumor growth. Ovariectomy (OVX) was performed in 12 sixty week-old female mice, then followed by a low-fat (5%, LF, n=6) or a high-fat (60%, HF, n=6) diet for 12 weeks. In the eighth week of the dietary program, 10(6) E0771 (mouse breast cancer) cells were injected in the left fourth mammary gland. Tumor size was monitored for 4 weeks. Body weights were monitored weekly. At the end of the experiment, blood samples, visceral fat and tumors were collected for measuring VEGF expression using ELISA and intratumoral microvessel density (IMD) using CD31 immunochemistry. Body weight was significantly increased in OVX/HF mice, compared to OVX/LF group (55.3±1.7 vs. 41.5±1.5 g; p < 0.01). There was a two-fold increase in the ratio of visceral fat/BW in OVX/HF mice, compared to those in OVX/LF group (0.062±0.005 vs. 0.032±0.003; p < 0.01). Postmenopausal obesity significantly increased breast tumor weight over the control (4.62±0.63 vs. 1.98±0.27 g; p < 0.01) and IMD (173±3.7 vs. 139±4.3 IM#/mm^2; p < 0.01). Tumor VEGF levels were higher in OVX/HF mice, compared to OVX/LF group (73.3±3.8 vs. 49.5±4.3 pg/mg protein; p < 0.01). Plasma VEGF levels (69±7.1 vs. 48±3.5 pg/ml) and visceral fat VEGF levels (424.4±39.5 vs. 208.5±22.4 pg/mg protein) were significantly increased in OVX/HF mice, compared to OVX/LF group, respectively (n=6; p < 0.01). Interestingly, adipose tissue primary culture showed that subcutaneous fat released more VEGF, compared to visceral fat (6.77±1.14 vs. 0.94±0.16 pg/mg tissue; n=6; p < 0.01). These findings support the hypothesis that postmenopausal obesity promotes tumor angiogenesis and breast cancer

  18. Ground water pollution by arsenic and its effects on health. Involvement of metabolic methylation in arsenic-induced genetic damage and tumorigenesis; Muki hiso no mechiru ka taisha to idenshi shogaisei narabini shuyo yuhatsusei

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, K. [Nihon Univ., Tokyo (Japan)] Okada, S. [Shizuoka Prefecture (Japan)

    1997-07-10

    Drinking water contamination has become a worldwide problem. It is pointed out that re-evaluation of genetic damage with carcinogen is considered as an important problem particularly arsenic`s effects on health. To explain the genetic damage development mechanism of arsenic compound, results of the research conducted on the action of arsenic compound which develops during metabolic methylation process and inorganic arsenic are explained in this paper. The results of the study are summarized as follows. Arsenic genetic damage mutation is caused by dimethyl arsenic in main metabolism than inorganic arsenic. Lung DNA damage is induced by the interaction of O2 and arsenic peroxide radical. Dimethyl arsenic shows very important effect on lung cancer formation process which is induced based on 4-nitroquinoline-1-oxide (4NQO). It not only promotes lung cancer but it also plays an important role in malignant tumor`s mutation. 25 refs., 2 figs.

  19. Arsenic efflux from Microcystis aeruginosa under different phosphate regimes.

    Directory of Open Access Journals (Sweden)

    Changzhou Yan

    Full Text Available Phytoplankton plays an important role in arsenic speciation, distribution, and cycling in freshwater environments. Little information, however, is available on arsenic efflux from the cyanobacteria Microcystis aeruginosa under different phosphate regimes. This study investigated M. aeruginosa arsenic efflux and speciation by pre-exposing it to 10 µM arsenate or arsenite for 24 h during limited (12 h and extended (13 d depuration periods under phosphate enriched (+P and phosphate depleted (-P treatments. Arsenate was the predominant species detected in algal cells throughout the depuration period while arsenite only accounted for no greater than 45% of intracellular arsenic. During the limited depuration period, arsenic efflux occurred rapidly and only arsenate was detected in solutions. During the extended depuration period, however, arsenate and dimethylarsinic acid (DMA were found to be the two predominant arsenic species detected in solutions under -P treatments, but arsenate was the only species detected under +P treatments. Experimental results also suggest that phosphorus has a significant effect in accelerating arsenic efflux and promoting arsenite bio-oxidation in M. aeruginosa. Furthermore, phosphorus depletion can reduce arsenic efflux from algal cells as well as accelerate arsenic reduction and methylation. These findings can contribute to our understanding of arsenic biogeochemistry in aquatic environments and its potential environmental risks under different phosphorus levels.

  20. Arsenic Trioxide Injection

    Science.gov (United States)

    Arsenic trioxide is used to treat acute promyelocytic leukemia (APL; a type of cancer in which there ... worsened following treatment with other types of chemotherapy. Arsenic trioxide is in a class of medications called ...

  1. MGMT promoter methylation is associated with temozolomide response and prolonged progression-free survival in disseminated cutaneous melanoma.

    Science.gov (United States)

    Tuominen, Rainer; Jewell, Rosalyn; van den Oord, Joost J; Wolter, Pascal; Stierner, Ulrika; Lindholm, Christer; Hertzman Johansson, Carolina; Lindén, Diana; Johansson, Hemming; Frostvik Stolt, Marianne; Walker, Christy; Snowden, Helen; Newton-Bishop, Julia; Hansson, Johan; Egyházi Brage, Suzanne

    2015-06-15

    To investigate the predictive and prognostic value of O(6) -methylguanine DNA methyltransferase (MGMT) inactivation by analyses of promoter methylation in pretreatment tumor biopsies from patients with cutaneous melanoma treated with dacarbazine (DTIC) or temozolomide (TMZ) were performed. The patient cohorts consisted of Belgian and Swedish disseminated melanoma patients. Patients were subdivided into those receiving single-agent treatment with DTIC/TMZ (cohort S, n = 74) and those treated with combination chemotherapy including DTIC/TMZ (cohort C, n = 79). Median follow-up was 248 and 336 days for cohort S and cohort C, respectively. MGMT promoter methylation was assessed by three methods. The methylation-related transcriptional silencing of MGMT mRNA expression was assessed by real-time RT-PCR. Response to chemotherapy and progression-free survival (PFS) and overall survival were correlated to MGMT promoter methylation status. MGMT promoter methylation was detected in tumor biopsies from 21.5 % of the patients. MGMT mRNA was found to be significantly lower in tumors positive for MGMT promoter methylation compared to tumors without methylation in both treatment cohorts (p < 0.005). DTIC/TMZ therapy response rate was found to be significantly associated with MGMT promoter methylation in cohort S (p = 0.0005), but did not reach significance in cohort C (p = 0.16). Significantly longer PFS was observed among patients with MGMT promoter-methylated tumors (p = 0.002). Multivariate Cox regression analysis identified presence of MGMT promoter methylation as an independent variable associated with longer PFS. Together, this implies that MGMT promoter methylation is associated with response to single-agent DTIC/TMZ and longer PFS in disseminated cutaneous melanoma. PMID:25400033

  2. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

  3. Twisted epithelial-to-mesenchymal transition promotes progression of surviving bladder cancer T24 cells with hTERT-dysfunction.

    Directory of Open Access Journals (Sweden)

    Yan Xue

    Full Text Available BACKGROUND: Human cancer cells maintain telomeres to protect cells from senescence through telomerase activity (TA or alternative lengthening of telomeres (ALT in different cell types. Moreover, cellular senescence can be bypassed by Epithelial-to-mesenchymal transition (EMT during cancer progression in diverse solid tumors. However, it has not been elucidated the characteristics of telomere maintenance and progression ability after long-term culture in bladder cancer T24 cells with hTERT dysfunction. METHODOLOGY/PRINCIPAL FINDINGS: In this study, by using a dominant negative mutant human telomerase reverse transcriptase (hTERT vector to inhibit TA in bladder cancer T24 cells, we observed the appearance of long phenotype of telomere length and the ALT-associated PML body (APB complex after the 27(th passage, indicating the occurrence of ALT-like pathway in surviving T24/DN868A cells with telomerase inhibition. Meanwhile, telomerase inhibition resulted in significant EMT as shown by change in cellular morphology concomitant with variation of EMT markers. Consistently, the surviving T24/DN868A cells showed increased progression ability in vitro and in vivo. In addition, we found Twist was activated to mediate EMT in surviving T24/DN868A samples. CONCLUSIONS/SIGNIFICANCE: Taken together, our findings indicate that bladder cancer T24 cells may undergo the telomerase-to-ALT-like conversion and promote cancer progression at advanced stages through promoting EMT, thus providing novel possible insight into the mechanism of resistance to telomerase inhibitors in cancer treatment.

  4. Polymorphisms in the CCR5 promoter region influence disease progression in perinatally human immunodeficiency virus type 1-infected children.

    Science.gov (United States)

    Ometto, L; Bertorelle, R; Mainardi, M; Zanchetta, M; Tognazzo, S; Rampon, O; Ruga, E; Chieco-Bianchi, L; De Rossi, A

    2001-03-01

    The effect of CC-chemokine receptor 5 (CCR5) promoter polymorphisms on the natural history of human immunodeficiency virus (HIV) disease was studied in 73 HIV-1-infected children. The CCR5(59338-59537) promoter haplotype, CCR5-59029A/G polymorphism, and CCR5Delta32 and CCR2-64I alterations were investigated. After exclusion of carriers of CCR5Delta32 or CCR2-64I, Kaplan-Meier analysis disclosed that children with the P1/P1(59353C,59356C,59402A) genotype progressed faster to disease than did children with other haplotypes (P=.016). When CCR2-64I carriers were included, this effect had borderline significance (P=.065) and was lost when CCR5Delta32 carriers were also considered (P=.387). The P1/P1 effect was strongest early after infection, when progression to disease was mainly associated with CCR5 coreceptor-using viruses. These results indicate that the P1/P1 genotype is predictive of rapid progression in HIV-1-infected children lacking CCR5Delta32 or CCR5-64I alleles. The observation of a linkage disequilibrium between P1 and 59029A might explain the previously reported association between 59029A homozygosity and rapid disease progression. PMID:11181160

  5. OCT4 increases BIRC5 and CCND1 expression and promotes cancer progression in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    OCT4 and BIRC5 are preferentially expressed in human cancer cells and mediate cancer cell survival and tumor maintenance. However, the molecular mechanism that regulates OCT4 and BIRC5 expression is not well characterized. By manipulating OCT4 and BIRC5 expression in hepatocellular carcinoma (HCC) cell lines, the regulatory mechanism of OCT4 on BIRC5 and CCND1 were investigated. Increasing or decreasing OCT4 expression could enhance or suppress BIRC5 expression, respectively, by regulating the activity of BIRC5 promoter. Because there is no binding site for OCT4 within BIRC5 promoter, the effect of OCT4 on BIRC5 promoter is indirect. An octamer motif for OCT4 in the CCND1 promoter has directly and partly participated in the regulation of CCND1 promoter activity, suggesting that OCT4 also could upregulated the expression of CCND1. Co-suppression of OCT4 and BIRC5 induced cancer cell apoptosis and cell cycle arrest, thereby efficiently inhibiting the proliferative activity of cancer cells and suppressing the growth of HCC xenogrfts in nude mice. OCT4 can upregulate BIRC5 and CCND1 expression by increasing their promoter activity. These factors collusively promotes HCC cell proliferation, and co-suppression of OCT4 and BIRC5 is potentially beneficial for HCC treatment

  6. Arsenic removal from water

    Science.gov (United States)

    Moore, Robert C.; Anderson, D. Richard

    2007-07-24

    Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

  7. PUMA promotes apoptosis of hematopoietic progenitors driving leukemic progression in a mouse model of myelodysplasia.

    Science.gov (United States)

    Guirguis, A A; Slape, C I; Failla, L M; Saw, J; Tremblay, C S; Powell, D R; Rossello, F; Wei, A; Strasser, A; Curtis, D J

    2016-06-01

    Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis with resultant cytopenias. Increased apoptosis and aberrantly functioning progenitors are thought to contribute to this phenotype. As is the case for other malignancies, overcoming apoptosis is believed to be important in progression toward acute myeloid leukemia (AML). Using the NUP98-HOXD13 (NHD13) transgenic mouse model of MDS, we previously reported that overexpression of the anti-apoptotic protein BCL2, blocked apoptosis and improved cytopenias, paradoxically, delaying leukemic progression. To further understand this surprising result, we examined the role of p53 and its pro-apoptotic effectors, PUMA and NOXA in NHD13 mice. The absence of p53 or PUMA but not NOXA reduced apoptosis and expanded the numbers of MDS-repopulating cells. Despite a similar effect on apoptosis and cell numbers, the absence of p53 and PUMA had diametrically opposed effects on progression to AML: absence of p53 accelerated leukemic progression, while absence of PUMA significantly delayed progression. This may be explained in part by differences in cellular responses to DNA damage. The absence of p53 led to higher levels of γ-H2AX (indicative of persistent DNA lesions) while PUMA-deficient NHD13 progenitors resolved DNA lesions in a manner comparable to wild-type cells. These results suggest that targeting PUMA may improve the cytopenias of MDS without a detrimental effect on leukemic progression thus warranting further investigation. PMID:26742432

  8. Long noncoding RNA PVT1 promotes cervical cancer progression through epigenetically silencing miR-200b.

    Science.gov (United States)

    Zhang, Shaorong; Zhang, Guanli; Liu, Jingying

    2016-08-01

    Long noncoding RNA PVT1 has been reported to be dysregulated and play vital roles in a variety of cancers. However, the functions and molecular mechanisms of PVT1 in cervical cancer remain unclear. The objective of this study was to investigate the expression, clinical significance, biological roles, and underlying functional mechanisms of PVT1 in cervical cancer. Our results revealed that PVT1 is upregulated in cervical cancer tissues. Enhanced expression of PVT1 is associated with larger tumor size, advanced International Federation of Gynecology and Obstetrics stage, and poor prognosis of cervical cancer patients. Using gain-of-function and loss-of-function approaches, we demonstrated that overexpression of PVT1 promotes cervical cancer cells proliferation, cell cycle progression and migration, and depletion of PVT1 inhibits cervical cancer cell proliferation, cell cycle progression, and migration. Mechanistically, we verified that PVT1 binds to EZH2, recruits EZH2 to the miR-200b promoter, increases histone H3K27 trimethylation level on the miR-200b promoter, and inhibits miR-200b expression. Furthermore, the effects of PVT1 on cervical cell proliferation and migration depend upon silencing of miR-200b. Taken together, our findings confirmed that PVT1 functions as an oncogene in cervical cancer and indicated that PVT1 is not only an important prognostic marker, but also a potential therapy target for cervical cancer. PMID:27272214

  9. MICROBIAL DRIVEN TLR5-DEPENDENT SIGNALING GOVERNS DISTAL MALIGNANT PROGRESSION THROUGH TUMOR-PROMOTING INFLAMMATION

    Science.gov (United States)

    Rutkowski, Melanie R.; Stephen, Tom L.; Svoronos, Nikolaos; Allegrezza, Michael J.; Tesone, Amelia J.; Perales-Puchalt, Alfredo; Brencicova, Eva; Escovar-Fadul, Ximena; Nguyen, Jenny M.; Cadungog, Mark G.; Zhang, Rugang; Salatino, Mariana; Tchou, Julia; Rabinovich, Gabriel A.; Conejo-Garcia, Jose R.

    2014-01-01

    The dominant TLR5R392X polymorphism abrogates flagellin responses in >7% of humans. We report that TLR5-dependent commensal bacteria drive malignant progression at extra-mucosal locations by increasing systemic IL-6, which drives mobilization of myeloid derived suppressor cells (MDSCs). Mechanistically, expanded granulocytic MDSCs cause γδ lymphocytes in TLR5-responsive tumors to secrete galectin-1, dampening anti-tumor immunity and accelerating malignant progression. In contrast, IL-17 is consistently up-regulated in TLR5-unresponsive tumor-bearing mice, but only accelerates malignant progression in IL-6-unresponsive tumors. Importantly, depletion of commensal bacteria abrogates TLR5-dependent differences in tumor growth. Contrasting differences in inflammatory cytokines and malignant evolution are recapitulated in TLR5-responsive/unresponsive ovarian and breast cancer patients. Therefore, inflammation, anti-tumor immunity and the clinical outcome of cancer patients are influenced by a common TLR5 polymorphism. PMID:25533336

  10. MicroRNA-135b promotes cancer progression by acting as a downstream effector of oncogenic pathways in colon cancer.

    Science.gov (United States)

    Valeri, Nicola; Braconi, Chiara; Gasparini, Pierluigi; Murgia, Claudio; Lampis, Andrea; Paulus-Hock, Viola; Hart, Jonathan R; Ueno, Lynn; Grivennikov, Sergei I; Lovat, Francesca; Paone, Alessio; Cascione, Luciano; Sumani, Khlea M; Veronese, Angelo; Fabbri, Muller; Carasi, Stefania; Alder, Hansjuerg; Lanza, Giovanni; Gafa', Roberta; Moyer, Mary P; Ridgway, Rachel A; Cordero, Julia; Nuovo, Gerard J; Frankel, Wendy L; Rugge, Massimo; Fassan, Matteo; Groden, Joanna; Vogt, Peter K; Karin, Michael; Sansom, Owen J; Croce, Carlo M

    2014-04-14

    MicroRNA deregulation is frequent in human colorectal cancers (CRCs), but little is known as to whether it represents a bystander event or actually drives tumor progression in vivo. We show that miR-135b overexpression is triggered in mice and humans by APC loss, PTEN/PI3K pathway deregulation, and SRC overexpression and promotes tumor transformation and progression. We show that miR-135b upregulation is common in sporadic and inflammatory bowel disease-associated human CRCs and correlates with tumor stage and poor clinical outcome. Inhibition of miR-135b in CRC mouse models reduces tumor growth by controlling genes involved in proliferation, invasion, and apoptosis. We identify miR-135b as a key downsteam effector of oncogenic pathways and a potential target for CRC treatment. PMID:24735923

  11. Science as a Common Language in a Globalised World - Scientific Collaboration Promoting Progress, Building Bridges

    CERN Document Server

    CERN. Geneva. Audiovisual Unit

    2003-01-01

    International scientific collaboration and co-operation can accelerate the progress of science, help build bridges between diverse societies, and foster the development of science and technology in non-industrialised countries. This is possible because science is a common language (although the progress of science is often influenced by non-scientific factors). I shall describe examples of the role that scientific collaboration can play in bridge building and in conflict resolution. I shall then present a proposal for "Bridge Building Fellowships" which would contribute to strengthening scientific capacity in developing countries by helping to stem the brain drain and providing a basis for collaborations with scientists in industrialised countries.

  12. IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer

    OpenAIRE

    Abiko, K; Matsumura, N; Hamanishi, J; Horikawa, N.(Nagoya University, Nagoya, 464, Japan); Murakami, R; K. Yamaguchi; Yoshioka, Y; Baba, T; Konishi, I; Mandai, M

    2015-01-01

    Background: PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear. Methods: The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse...

  13. Matriptase promotes inflammatory cell accumulation and progression of established epidermal tumors

    DEFF Research Database (Denmark)

    Sales, K U; Friis, S; Abusleme, L;

    2015-01-01

    Deregulation of matriptase is a consistent feature of human epithelial cancers and correlates with poor disease outcome. We have previously shown that matriptase promotes multi-stage squamous cell carcinogenesis in transgenic mice through dual activation of pro-hepatocyte growth factor-cMet-Akt-m......Deregulation of matriptase is a consistent feature of human epithelial cancers and correlates with poor disease outcome. We have previously shown that matriptase promotes multi-stage squamous cell carcinogenesis in transgenic mice through dual activation of pro-hepatocyte growth factor...

  14. Environmental Source of Arsenic Exposure

    OpenAIRE

    Chung, Jin-Yong; Yu, Seung-Do; Hong, Young-Seoub

    2014-01-01

    Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a ...

  15. Knockdown of TWIST1 enhances arsenic trioxide- and ionizing radiation-induced cell death in lung cancer cells by promoting mitochondrial dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Sung-Keum; Kim, Jae-Hee; Choi, Ha-Na [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); Choe, Tae-Boo [Department of Microbiological Engineering, Kon-Kuk University, Gwangjin-gu, Seoul (Korea, Republic of); Hong, Seok-Il [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); Yi, Jae-Youn [Laboratory of Modulation of Radiobiological Responses, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of); Lee, Hyun-Gyu [Department of Microbiology and Immunology, College of Medicine, Yonsei University, 250 Seongsan-no, Seodaemun-gu, Seoul (Korea, Republic of); Lee, Yun-Han, E-mail: yhlee87@yuhs.ac [Department of Radiation Oncology, College of Medicine, Yonsei University, 250 Seongsan-no, Seodaemun-gu, Seoul (Korea, Republic of); Park, In-Chul, E-mail: parkic@kcch.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung-dong, Nowon-gu, Seoul (Korea, Republic of)

    2014-07-11

    Highlights: • Knockdown of TWIST1 enhanced ATO- and IR-induced cell death in NSCLCs. • Intracellular ROS levels were increased in cells treated with TWIST1 siRNA. • TWIST1 siRNA induced MMP loss and mitochondrial fragmentation. • TWIST1 siRNA upregulated the fission-related proteins FIS1 and DRP1. - Abstract: TWIST1 is implicated in the process of epithelial mesenchymal transition, metastasis, stemness, and drug resistance in cancer cells, and therefore is a potential target for cancer therapy. In the present study, we found that knockdown of TWIST1 by small interfering RNA (siRNA) enhanced arsenic trioxide (ATO)- and ionizing radiation (IR)-induced cell death in non-small-cell lung cancer cells. Interestingly, intracellular reactive oxygen species levels were increased in cells treated with TWIST1 siRNA and further increased by co-treatment with ATO or IR. Pretreatment of lung cancer cells with the antioxidant N-acetyl-cysteine markedly suppressed the cell death induced by combined treatment with TWIST1 siRNA and ATO or IR. Moreover, treatment of cells with TWIST1 siRNA induced mitochondrial membrane depolarization and significantly increased mitochondrial fragmentation (fission) and upregulated the fission-related proteins FIS1 and DRP1. Collectively, our results demonstrate that siRNA-mediated TWIST1 knockdown induces mitochondrial dysfunction and enhances IR- and ATO-induced cell death in lung cancer cells.

  16. Knockdown of TWIST1 enhances arsenic trioxide- and ionizing radiation-induced cell death in lung cancer cells by promoting mitochondrial dysfunction

    International Nuclear Information System (INIS)

    Highlights: • Knockdown of TWIST1 enhanced ATO- and IR-induced cell death in NSCLCs. • Intracellular ROS levels were increased in cells treated with TWIST1 siRNA. • TWIST1 siRNA induced MMP loss and mitochondrial fragmentation. • TWIST1 siRNA upregulated the fission-related proteins FIS1 and DRP1. - Abstract: TWIST1 is implicated in the process of epithelial mesenchymal transition, metastasis, stemness, and drug resistance in cancer cells, and therefore is a potential target for cancer therapy. In the present study, we found that knockdown of TWIST1 by small interfering RNA (siRNA) enhanced arsenic trioxide (ATO)- and ionizing radiation (IR)-induced cell death in non-small-cell lung cancer cells. Interestingly, intracellular reactive oxygen species levels were increased in cells treated with TWIST1 siRNA and further increased by co-treatment with ATO or IR. Pretreatment of lung cancer cells with the antioxidant N-acetyl-cysteine markedly suppressed the cell death induced by combined treatment with TWIST1 siRNA and ATO or IR. Moreover, treatment of cells with TWIST1 siRNA induced mitochondrial membrane depolarization and significantly increased mitochondrial fragmentation (fission) and upregulated the fission-related proteins FIS1 and DRP1. Collectively, our results demonstrate that siRNA-mediated TWIST1 knockdown induces mitochondrial dysfunction and enhances IR- and ATO-induced cell death in lung cancer cells

  17. Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/β-catenin signaling pathway

    International Nuclear Information System (INIS)

    Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of β-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of β-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited β-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/β-catenin signaling pathway. -- Highlights: ► Carcinogenic metals in drinking water promote colorectal tumor formation in vivo. ► Carcinogenic metals induce β-catenin activation in vivo and in vitro. ► ROS generation induced by carcinogenic metals mediated β-catenin activation.

  18. Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/β-catenin signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Mandal, Ardhendu K. [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Saito, Hiroshi [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Pulliam, Joseph F.; Lee, Eun Y. [Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY 40536 (United States); Ke, Zun-Ji; Lu, Jian; Ding, Songze [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Li, Li [Department of Family Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Shelton, Brent J.; Tucker, Thomas [Markey Cancer Control Program, University of Kentucky, Lexington, KY 40504 (United States); Evers, B. Mark [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)

    2012-07-01

    Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of β-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of β-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited β-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/β-catenin signaling pathway. -- Highlights: ► Carcinogenic metals in drinking water promote colorectal tumor formation in vivo. ► Carcinogenic metals induce β-catenin activation in vivo and in vitro. ► ROS generation induced by carcinogenic metals mediated β-catenin activation.

  19. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

    OpenAIRE

    Harris, Robin B; Burgess, Jefferey L.; Maria Mercedes Meza-Montenegro; Luis Enrique Gutiérrez-Millán; Mary Kay O’Rourke; Jason Roberge

    2012-01-01

    The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and...

  20. Fibroblast-derived MT1-MMP promotes tumor progression in vitro and in vivo

    OpenAIRE

    Vick Catherine C; Holmbeck Kenn; Matrisian Lynn M; Zhang Wenyue; Rosenthal Eben L

    2006-01-01

    Abstract Background Identification of fibroblast derived factors in tumor progression has the potential to provide novel molecular targets for modulating tumor cell growth and metastasis. Multiple matrix metalloproteases (MMPs) are expressed by both mesenchymal and epithelial cells within head and neck squamous cell carcinomas (HNSCCs), but the relative importance of these enzymes and the cell source is the subject of controversy. Methods The invasive potential of HNSCC tumor cells were asses...

  1. Pro-oncogene Pokemon promotes breast cancer progression by upregulating survivin expression

    OpenAIRE

    ZU, XUYU; Ma, Jun; Liu, Hongxia; Liu, Feng; Tan, Chunyan; Yu, Lingling; Wang, Jue; Xie, Zhenhua; Cao, Deliang; Jiang, Yuyang

    2011-01-01

    Introduction Pokemon is an oncogenic transcription factor involved in cell growth, differentiation and oncogenesis, but little is known about its role in human breast cancer. In this study, we aimed to reveal the role of Pokemon in breast cancer progression and patient survival and to understand its underlying mechanisms. Methods Tissue microarray analysis of breast cancer tissues from patients with complete clinicopathological data and more than 20 years of follow-up were used to evaluate Po...

  2. Hypoxia Mediated Downregulation of miRNA Biogenesis Promotes Tumor Progression

    OpenAIRE

    Rupaimoole, Rajesha; Wu, Sherry Y.; Pradeep, Sunila; Ivan, Cristina; Pecot, Chad V.; Gharpure, Kshipra M.; Nagaraja, Archana S; Armaiz-Pena, Guillermo N.; McGuire, Michael; Zand, Behrouz; Dalton, Heather J.; Filant, Justyna; Miller, Justin Bottsford; Lu, Chunhua; Sadaoui, Nouara C.

    2014-01-01

    Cancer-related deregulation of miRNA biogenesis has been suggested, but the underlying mechanisms remain elusive. Here, we report a previously unrecognized effect of hypoxia in the downregulation of Drosha and Dicer in cancer cells that leads to dysregulation of miRNA biogenesis and increased tumor progression. We show that hypoxia mediated downregulation of Drosha is dependent on ETS1/ELK1 transcription factors. Moreover, mature miRNA array and deep sequencing studies reveal altered miRNA ma...

  3. Interleukin-17 Could Promote Breast Cancer Progression at Several Stages of the Disease

    OpenAIRE

    Thomas Welte; Xiang H.-F. Zhang

    2015-01-01

    Metastatic disease accounts for more than 90% of deaths from breast cancer. Yet the factors that trigger metastasis, often years after primary tumor removal, are not understood well. Recently the proinflammatory cytokine interleukin- (IL-) 17 family has been associated with poor prognosis in breast cancer. Here we review current literature on the pathogenic mechanisms driven by IL-17 during breast cancer progression and connect these findings to metastasis. These include (1) direct effects of...

  4. Factors that promote Progression in Schools Functioning as Professional Learning Community

    OpenAIRE

    Martine Leclerc; André C. Moreau; Catherine Dumouchel; François Sallafranque-St-Louis

    2012-01-01

    The purpose of this research is to identify factors that influence the functioning of a school working as a Professional Learning Community (PLC) and to analyze the links between these factors and the school’s progression. This research was developed within the context of an interpretative research paradigm. The primary data collection tool employed is a one-hour semistructured interview with each participant, thus allowing researchers to identify each participating school’s level of developm...

  5. Progress in Relevant Growth Factors Promoting the Growth of Hair Follicle

    OpenAIRE

    Wang, J. M.; J. T. Zhang

    2012-01-01

    Hair is a protective appendage on the body that is considered accessory structure of the integument. Hair follicle development takes place during fetal skin development and relies on tightly regulated ectodermal-mesodermal interactions. The morphological changes of the hair cycle have been very clear that hair morphogenesis and epidermal development are orchestrated by an array of growth factors. In this review, we summarize the major growth factors involved in promoting growth of hair follicles

  6. NMU signaling promotes endometrial cancer cell progression by modulating adhesion signaling.

    Science.gov (United States)

    Lin, Ting-Yu; Wu, Fang-Ju; Chang, Chia-Lin; Li, Zhongyou; Luo, Ching-Wei

    2016-03-01

    Neuromedin U (NMU) was originally named based on its strong uterine contractile activity, but little is known regarding its signaling/functions in utero. We identified that NMU and one of its receptors, NMUR2, are not only present in normal uterine endometrium but also co-expressed in endometrial cancer tissues, where the NMU level is correlated with the malignant grades and survival of patients. Cell-based assays further confirmed that NMU signaling can promote cell motility and proliferation of endometrial cancer cells derived from grade II tumors. Activation of NMU pathway in these endometrial cancer cells is required in order to sustain expression of various adhesion molecules, such as CD44 and integrin alpha1, as well as production of their corresponding extracellular matrix ligands, hyaluronan and collagen IV; it also increased the activity of SRC and its downstream proteins RHOA and RAC1. Thus, it is concluded that NMU pathway positively controls the adhesion signaling-SRC-Rho GTPase axis in the tested endometrial cancer cells and that changes in cell motility and proliferation can occur when there is manipulation of NMU signaling in these cells either in vitro or in vivo. Intriguingly, this novel mechanism also explains how NMU signaling promotes the EGFR-driven and TGFβ receptor-driven mesenchymal transitions. Through the above axis, NMU signaling not only can promote malignancy of the tested endometrial cancer cells directly, but also helps these cells to become more sensitive to niche growth factors in their microenvironment. PMID:26849234

  7. Prolyl-4-hydroxylase α subunit 2 promotes breast cancer progression and metastasis by regulating collagen deposition

    International Nuclear Information System (INIS)

    Increased collagen deposition provides physical and biochemical signals to support tumor growth and invasion during breast cancer development. Therefore, inhibition of collagen synthesis and deposition has been considered a strategy to suppress breast cancer progression. Collagen prolyl-4-hydroxylase α subunit 2 (P4HA2), an enzyme hydroxylating proline residues in -X-Pro-Gly- sequences, is a potential therapeutic target for the disorders associated with increased collagen deposition. However, expression and function of P4HA2 in breast cancer progression are not well investigated. Gene co-expression analysis was performed in the published microarray datasets to identify potential regulators of collagen I, III, and IV in human breast cancer tissue. Expression of P4HA2 was silenced by shRNAs, and its activity was inhibited by 1, 4-DPCA, a prolyl-4-hydroxylase inhibitor. Three-dimensional culture assay was used to analyze roles of P4HA2 in regulating malignant phenotypes of breast cancer cells. Reduced deposition of collagen I and IV was detected by Western blotting and immunofluorescence. Control and P4HA2-silenced breast cancer cells were injected into fat pad and tail vein of SCID mice to examine effect of P4HA2 on tumor growth and lung metastasis. Using gene co-expression analysis, we showed that P4HA2 was associated with expression of Col1A1, Col3A1, and Col4A1 during breast cancer development and progression. P4HA2 mRNA levels were significantly upregulated in breast cancer compared to normal mammary tissue. Increased mRNA levels of P4HA2 correlated with poor clinical outcome in breast cancer patients, which is independent of estrogen receptor status. Silencing P4HA2 expression or treatment with the P4HA inhibitor significantly inhibited cell proliferation and suppressed aggressive phenotypes of breast cancer cells in 3D culture, accompanied by reduced deposition of collagen I and IV. We also found that knockdown of P4HA2 inhibited mammary tumor growth and

  8. Arsenic in ground-water under oxidizing conditions, south-west United States

    Science.gov (United States)

    Robertson, F.N.

    1989-01-01

    Concentrations of dissolved arsenic in ground-water in alluvial basins of Arizona commonly exceed 50 ??g L-1 and reach values as large as 1,300 ??g L-1. Arsenic speciation analyses show that arsenic occurs in the fully oxidized state of plus 5 (As+5), most likely in the form of HAsO4???2, under existing oxidizing and pH conditions. Arsenic in source areas presumably is oxidized to soluble As before transport into the basin or, if after transport, before burial. Probable sources of arsenic are the sulphide and arsenide deposits in the mineralized areas of the mountains surrounding the basins. Arsenic content of alluvial material ranged from 2 to 88 ppm. Occurrence and removal of arsenic in ground-water are related to the pH and the redox condition of the ground-water, the oxidation state of arsenic, and sorption or exchange. Within basins, dissolved arsenic correlates (Pwater. Silicate hydrolysis reactions, as defined within the alluvial basins, under closed conditions cause increases in pH basinward and would promote desorption. Within the region, large concentrations of arsenic are commonly associated with the central parts of basins whose chemistries evolve under closed conditions. Arsenic does not correlate with dissolved iron (r = 0.09) but may be partly controlled by iron in the solid phase. High solid-phase arsenic contents were found in red clay beds. Large concentrations of arsenic also were found in water associated with red clay beds. Basins that contain the larger concentrations are bounded primarily by basalt and andesite, suggesting that the iron content as well as the arsenic content of the basin fill may play a role in the occurrence of arsenic in ground-water. Under oxidizing conditions in Arizona, arsenic in ground-water appears to be controlled in part by sorption or desorption of HAsO4???2 on active ferric oxyhydroxide surfaces. ?? 1989 Sciences and Technology Letters.

  9. Arsenic removal from flowing irrigation water in bangladesh: impacts of channel properties.

    Science.gov (United States)

    Lineberger, Ethan M; Badruzzaman, A Borhan M; Ali, M Ashraf; Polizzotto, Matthew L

    2013-11-01

    Across Bangladesh, dry-season irrigation with arsenic-contaminated well water is loading arsenic onto rice paddies, leading to increased arsenic concentrations in plants, diminished crop yields, and increased human health risks. As irrigation water flows through conveyance channels between wells and rice fields, arsenic concentrations change over space and time, indicating that channels may provide a location for removing arsenic from solution. However, few studies have systematically evaluated the processes controlling arsenic concentrations in irrigation channels, limiting the ability to manipulate these systems and enhance arsenic removal from solution. The central goal of this study was to quantify how channel design affected removal of dissolved arsenic from flowing irrigation water. Field experiments were conducted in Bangladesh using a chemically constant source of arsenic-contaminated irrigation water and an array of constructed channels with varying geometries. The resulting hydraulic conditions affected the quantity of arsenic removed from solution within the channels by promoting known hydrogeochemical processes. Channels three times the width of control channels removed ∼3 times the mass of arsenic over 32 min of flowing conditions, whereas negligible arsenic removal was observed in tarp-lined channels, which prevented soil-water contact. Arsenic removal from solution was ∼7 times higher in a winding, 200-m-long channel than in the straight, 45-m-long control channels. Arsenic concentrations were governed by oxidative iron-arsenic coprecipitation within the water column, sorption to soils, and phosphate competition. Collectively, these results suggest that better design and management of irrigation channels may play a part in arsenic mitigation strategies for rice fields in Southern Asia. PMID:25602413

  10. Dissolution of Arsenic Minerals Mediated by Dissimilatory Arsenate Reducing Bacteria: Estimation of the Physiological Potential for Arsenic Mobilization

    Directory of Open Access Journals (Sweden)

    Drewniak Lukasz

    2014-01-01

    Full Text Available The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V reduction, were isolated from microbial mats from an ancient gold mine. All of the isolated strains: (i produced siderophores that promote dissolution of minerals, (ii were resistant to dissolved arsenic compounds, (iii were able to use the dissolved arsenates as the terminal electron acceptor, and (iii were able to use copper minerals containing arsenic minerals (e.g., enargite as a respiratory substrate. Based on the results obtained in this study, we postulate that arsenic can be released from some As-bearing polymetallic minerals (such as copper ore concentrates or middlings under reductive conditions by dissimilatory arsenate reducers in indirect processes.

  11. Slug-upregulated miR-221 promotes breast cancer progression through suppressing E-cadherin expression.

    Science.gov (United States)

    Pan, Yi; Li, Jing; Zhang, Yaqin; Wang, Nan; Liang, Hongwei; Liu, Yuan; Zhang, Chen-Yu; Zen, Ke; Gu, Hongwei

    2016-01-01

    It is generally regarded that E-cadherin is downregulated during tumorigenesis via Snail/Slug-mediated E-cadherin transcriptional reduction. However, this transcriptional suppressive mechanism cannot explain the failure of producing E-cadherin protein in metastatic breast cancer cells after overexpressing E-cadherin mRNA. Here we reveal a novel mechanism that E-cadherin is post-transcriptionally regulated by Slug-promoted miR-221, which serves as an additional blocker for E-cadherin expression in metastatic tumor cells. Profiling the predicted E-cadherin-targeting miRNAs in breast cancer tissues and cells showed that miR-221 was abundantly expressed in breast tumor and metastatic MDA-MB-231 cells and its level was significantly higher in breast tumor or MDA-MB-231 cells than in distal non-tumor tissue and low-metastatic MCF-7 cells, respectively. MiR-221, which level inversely correlated with E-cadherin level in breast cancer cells, targeted E-cadherin mRNA open reading frame (ORF) and suppressed E-cadherin protein expression. Depleting or increasing miR-221 level in breast cancer cells induced or decreased E-cadherin protein level, leading to suppressing or promoting tumor cell progression, respectively. Moreover, miR-221 was specifically upregulated by Slug but not Snail. TGF-β treatment enhanced Slug activity and thus increased miR-221 level in MCF-7 cells. In summary, our results provide the first evidence that Slug-upregulated miR-221 promotes breast cancer progression via reducing E-cadherin expression. PMID:27174021

  12. Interleukin-6 Gene Promoter-572 C Allele May Play a Role in Rate of Disease Progression in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Judith M. Greer

    2012-10-01

    Full Text Available Multiple sclerosis (MS is an inflammatory demyelinating disease affecting the central nervous system. Although the exact pathogenesis of MS is unknown, it is generally considered to be an autoimmune disease, with numerous genetic and environmental factors determining disease susceptibility and severity. One important mediator of immune responses and inflammation is interleukin-6 (IL-6. Previously, elevated levels of IL-6 in mononuclear cells in blood and in brain tissue from MS patients have been reported. Various polymorphisms in the promoter region of the IL6 gene have also been linked with IL-6 protein levels. In MS, several small studies have investigated whether two IL6 promoter polymorphisms (−597 G>A and −174 G>C correlate with MS susceptibility, but with varying results. In the present study, we analyzed these polymorphisms, together with an additional polymorphism (−572 G>C in 279 healthy controls and 509 patients with MS. We found no significant differences between MS patients and healthy controls for the different −597 or −174 IL6 promoter alleles or genotypes. There was a slight reduction in the percentage of individuals with MS who carried a C allele at position −572, although this was not significant after correction for multiple comparisons. Interestingly, however, the −572 C allele showed a significant correlation with the MS severity score, suggesting a possible role in disease progression.

  13. B-RafV600E and thrombospondin-1 promote thyroid cancer progression

    OpenAIRE

    Nucera, Carmelo; Porrello, Alessandro; Antonello, Zeus Andrea; Mekel, Michal; Nehs, Matthew A.; Giordano, Thomas J.; Gerald, Damien; Benjamin, Laura E.; Priolo, Carmen; Puxeddu, Efisio; Finn, Stephen; Jarzab, Barbara; Hodin, Richard A.; Pontecorvi, Alfredo; Nose, Vânia

    2010-01-01

    Although B-RafV600E is the most common somatic mutation in papillary thyroid carcinoma (PTC), how it induces tumor aggressiveness is not fully understood. Using gene set enrichment analysis and in vitro and in vivo functional studies, we identified and validated a B-RafV600E gene set signature associated with tumor progression in PTCs. An independent cohort of B-RafV600E-positive PTCs showed significantly higher expression levels of many extracellular matrix genes compared with controls. We p...

  14. SCF, regulated by HIF-1α, promotes pancreatic ductal adenocarcinoma cell progression.

    Directory of Open Access Journals (Sweden)

    Chuntao Gao

    Full Text Available Stem cell factor (SCF and hypoxia-inducible factor-1α (HIF-1α both have important functions in pancreatic ductal adenocarcinoma (PDAC. This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP assay, and luciferase assay analysis. The SCF level was also correlated with lymph node metastasis and the pathological tumor node metastasis (pTNM stage in PDAC samples. The SCF higher-expression group had significantly lower survival rates than the SCF lower-expression group (p<0.05. Hypoxia up-regulated the expression of SCF through the hypoxia-inducible factor (HIF-1α in PDAC cells at the protein and RNA levels. When HIF-1α was knocked down by RNA interference, the SCF level decreased significantly. Additionally, ChIP and luciferase results demonstrated that HIF-1α can directly bind to the hypoxia response element (HRE region of the SCF promoter and activate the SCF transcription under hypoxia. The results of colony formation, cell scratch, and transwell migration assay showed that SCF promoted the proliferation and invasion of PANC-1 cells under hypoxia. Furthermore, the down-regulated ability of cell proliferation and invasion following HIF-1α knockdown was rescued by adding exogenous SCF under hypoxia in vitro. Finally, when the HIF-1α expression was inhibited by digoxin, the tumor volume and the SCF level decreased, thereby proving the relationship between HIF-1α and SCF in vivo. In conclusion, SCF is an important factor for the growth of PDAC. In our experiments, we proved that SCF, a downstream gene of HIF-1α, can promote the development of PDAC under hypoxia. Thus, SCF might be a potential therapeutic target for PDAC.

  15. SCF, Regulated by HIF-1α, Promotes Pancreatic Ductal Adenocarcinoma Cell Progression

    Science.gov (United States)

    Chen, Jing; Ren, He; Zhang, Huan; Wang, Xiuchao; Lang, Mingxiao; Liu, Jingcheng; Gao, Song; Zhao, Xiao; Sheng, Jun; Yuan, Zhanna; Hao, Jihui

    2015-01-01

    Stem cell factor (SCF) and hypoxia-inducible factor-1α (HIF-1α) both have important functions in pancreatic ductal adenocarcinoma (PDAC). This study aims to analyze the expression and clinicopathological significance of SCF and HIF-1α in PDAC specimens and explore the molecular mechanism at PDAC cells in vitro and in vivo. We showed that the expression of SCF was significantly correlated with HIF-1α expression via Western blot, PCR, chromatin immunoprecipitation (ChIP) assay, and luciferase assay analysis. The SCF level was also correlated with lymph node metastasis and the pathological tumor node metastasis (pTNM) stage in PDAC samples. The SCF higher-expression group had significantly lower survival rates than the SCF lower-expression group (p<0.05). Hypoxia up-regulated the expression of SCF through the hypoxia-inducible factor (HIF)-1α in PDAC cells at the protein and RNA levels. When HIF-1α was knocked down by RNA interference, the SCF level decreased significantly. Additionally, ChIP and luciferase results demonstrated that HIF-1α can directly bind to the hypoxia response element (HRE) region of the SCF promoter and activate the SCF transcription under hypoxia. The results of colony formation, cell scratch, and transwell migration assay showed that SCF promoted the proliferation and invasion of PANC-1 cells under hypoxia. Furthermore, the down-regulated ability of cell proliferation and invasion following HIF-1α knockdown was rescued by adding exogenous SCF under hypoxia in vitro. Finally, when the HIF-1α expression was inhibited by digoxin, the tumor volume and the SCF level decreased, thereby proving the relationship between HIF-1α and SCF in vivo. In conclusion, SCF is an important factor for the growth of PDAC. In our experiments, we proved that SCF, a downstream gene of HIF-1α, can promote the development of PDAC under hypoxia. Thus, SCF might be a potential therapeutic target for PDAC. PMID:25799412

  16. Nuclear vasohibin-2 promotes cell proliferation by inducing G0/G1 to S phase progression.

    Science.gov (United States)

    Ge, Qianqian; Zhou, Jia; Tu, Min; Xue, Xiaofeng; Li, Zhanjun; Lu, Zipeng; Wei, Jishu; Song, Guoxin; Chen, Jianmin; Guo, Feng; Jiang, Kuirong; Miao, Yi; Gao, Wentao

    2015-09-01

    As a member of the vasohibin (VASH2) family, VASH2 is localized intracellularly as a nuclear and cytoplasmic type. Cytoplasmic VASH2 is associated with carcinoma angiogenesis and malignant transformation and promotes cancer growth. However, the function of nuclear VASH2 has yet to be investigated. The aim of the present study was to detect the nuclear VASH2 expression profile in human organs and tissues by protein microarray technique. To examine the function of nuclear VASH2, we analyzed the relationship between nuclear VASH2 and Ki-67, and stably constructed VASH2 overexpression and knockdown in LO2 and HepG2 cell lines, based on a previous study in hepatic cells. The study was conducted using bromodeoxyuridine, immunofluorescent staining, western blot analysis and flow cytometry. Nuclear VASH2 was highly expressed in actively dividing cells in normal and cancer tissues. There was a significant positive correlation between nuclear VASH2 and Ki-67, indicating that nuclear VASH2 positively correlated with cell proliferation in normal and cancer tissues. The bromodeoxyuridine (BrdU) proliferation test showed that nuclear VASH2 increased the S-phase population and promoted cell proliferation, while VASH2 knockdown reduced BrdU absorbance. Cell cycle analysis revealed that nuclear VASH2 overexpression increased the S-phase population in LO2 and HepG2 cells, while nuclear VASH2 knockdown reduced the S-phase population and increased the G0/G1 population. The findings of this study challenge the classic view of VASH2, which was previously reported as an angiogenesis factor. Furthermore, to the best of our knowledge, these results are the first clinical data indicating that nuclear VASH2, but not cytoplasmic VASH2, promotes cell proliferation by driving the cell cycle from the G0/G1 to S phase. PMID:26177649

  17. Deletion of Interstitial Genes between TMPRSS2 and ERG Promotes Prostate Cancer Progression.

    Science.gov (United States)

    Linn, Douglas E; Penney, Kathryn L; Bronson, Roderick T; Mucci, Lorelei A; Li, Zhe

    2016-04-01

    TMPRSS2-ERG gene fusions that occur frequently in human prostate cancers can be generated either through insertional chromosomal rearrangement or by intrachromosomal deletion. Genetically, a key difference between these two mechanisms is that the latter results in deletion of a ∼3-Mb interstitial region containing genes with unexplored roles in prostate cancer. In this study, we characterized two mouse models recapitulating TMPRSS2-ERG insertion or deletion events in the background of prostate-specific PTEN deficiency. We found that only the mice that lacked the interstitial region developed prostate adenocarcinomas marked by poor differentiation and epithelial-to-mesenchymal transition. Mechanistic investigations identified several interstitial genes, including Ets2 and Bace2, whose reduced expression correlated in the gene homologs in human prostate cancer with biochemical relapse and lethal disease. Accordingly, PTEN-deficient mice with prostate-specific knockout of Ets2 exhibited marked progression of prostate adenocarcinomas that was partly attributed to activation of MAPK signaling. Collectively, our findings established that Ets2 is a tumor suppressor gene in prostate cancer, and its loss along with other genes within the TMPRSS2-ERG interstitial region contributes to disease progression. Cancer Res; 76(7); 1869-81. ©2016 AACR. PMID:26880803

  18. Radiation promotes colorectal cancer initiation and progression by inducing senescence-associated inflammatory responses.

    Science.gov (United States)

    Kim, S B; Bozeman, R G; Kaisani, A; Kim, W; Zhang, L; Richardson, J A; Wright, W E; Shay, J W

    2016-06-30

    Proton radiotherapy is becoming more common as protons induce more precise DNA damage at the tumor site with reduced side effects to adjacent normal tissues. However, the long-term biological effects of proton irradiation in cancer initiation compared with conventional photon irradiation are poorly characterized. In this study, using a human familial adenomatous polyposis syndrome susceptible mouse model, we show that whole-body irradiation with protons are more effective in inducing senescence-associated inflammatory responses (SIRs), which are involved in colon cancer initiation and progression. After proton irradiation, a subset of SIR genes (Troy, Sox17, Opg, Faim2, Lpo, Tlr2 and Ptges) and a gene known to be involved in invasiveness (Plat), along with the senescence-associated gene (P19Arf), are markedly increased. Following these changes, loss of Casein kinase Iα and induction of chronic DNA damage and TP53 mutations are increased compared with X-ray irradiation. Proton irradiation also increases the number of colonic polyps, carcinomas and invasive adenocarcinomas. Pretreatment with the non-steroidal anti-inflammatory drug, 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid-ethyl amide (CDDO-EA), reduces proton irradiation-associated SIR and tumorigenesis. Thus exposure to proton irradiation elicits significant changes in colorectal cancer initiation and progression that can be mitigated using CDDO-EA. PMID:26477319

  19. S100A4 promotes endometrial cancer progress through epithelial-mesenchymal transition regulation.

    Science.gov (United States)

    Hua, Teng; Liu, Shuangge; Xin, Xiaoyan; Cai, Liqiong; Shi, Rui; Chi, Shuqi; Feng, Dilu; Wang, Hongbo

    2016-06-01

    Epithelial-mesenchymal transition (EMT) is a major cause of endometrial cancer (EC) to initiate invasion and metastasis. S100A4, a calcium-binding protein, is implicated in multistage of tumorigenesis and tumor progression. The correlation between S100A4 and EMT in EC is still unclear. This study was aimed to clarify the role of S100A4 in EC and the relationship between S100A4 expression and EMT markers. S100A4, E-cadherin, and vimentin were detected in tissues of EC patients (n=50) by immunohistochemistry. The impact of S100A4 on EC cell proliferation, migration and invasion was investigated via RNA interference, and the correlation between S100A4 and EMT markers were also explored. The results showed that S100A4 was significantly increased in epithelial cells of EC compared with the normal endometrium (Psilencing of S100A4 remarkably attenuated EC cell migration and invasion. Significant morphological change accompanied with the downregulation of EMT markers, E-cadherin and vimentin were also observed. Aberrant S100A4 expression may predict EC progression and play an important role in regulating EC cell invasion through EMT regulation. Hence, S100A4 is a promising therapeutic target. PMID:27109209

  20. Drinking Water Fact Sheet: Arsenic

    OpenAIRE

    Mesner, Nancy; Daniels, Barbara

    2010-01-01

    This fact sheet provides information about arsenic in drinking water. It includes sections about what arsenic is, where it comes from, health concerns from exposure, drinking water standards, how to know if there is arsenic in a water supply and how to reduce arsenic in drinking water.

  1. Arsenic in Food

    Science.gov (United States)

    ... Biologics Animal & Veterinary Cosmetics Tobacco Products Food Home Food Foodborne Illness & Contaminants Metals Arsenic Share Tweet Linkedin Pin it More ... and previous or current use of arsenic-containing pesticides. Are there ... compounds in water, food, air, and soil: organic and inorganic (these together ...

  2. Disruption of brain zinc homeostasis promotes the pathophysiological progress of Alzheimer's disease.

    Science.gov (United States)

    Li, Lin-Bo; Wang, Zhan-You

    2016-06-01

    Zinc is abundant in the brain, where it plays an important role in synaptic plasticity and in learning; however, excessive zinc is toxic to neuronal cells, and dyshomeostasis of zinc in the brain is a contributing factor for Alzheimer's disease (AD). Deposition of zinc has been detected in senile plaques in the form of zinc-Aβ (β-amyloid) complexes. Recent studies have demonstrated that zinc exposure to the brain enhances β-amyloid precursor protein (APP) expression, amyloidogenic APP cleavage and plaque burden. Furthermore, alterations in zinc transporters, which are responsible for zinc homeostasis, occur in AD human brain and transgenic mouse models. These suggest that abnormal brain zinc homeostasis is involved in the pathophysiological progress of AD. PMID:26883958

  3. Carcinoembryonic antigen promotes colorectal cancer progression by targeting adherens junction complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bajenova, Olga, E-mail: o.bazhenova@spbu.ru [Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Department of Genetics and Biotechnology, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Department of Surgery and Biomedical Sciences, Creighton University, Omaha, NE 68178 (United States); Chaika, Nina [Department of Surgery and Biomedical Sciences, Creighton University, Omaha, NE 68178 (United States); Tolkunova, Elena; Davydov-Sinitsyn, Alexander [Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064 (Russian Federation); Gapon, Svetlana [Boston Children' s Hospital, Boston, MA 02115 (United States); Thomas, Peter [Department of Surgery and Biomedical Sciences, Creighton University, Omaha, NE 68178 (United States); O’Brien, Stephen [Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg 199034 (Russian Federation)

    2014-06-10

    Oncomarkers play important roles in the detection and management of human malignancies. Carcinoembryonic antigen (CEA, CEACAM5) and epithelial cadherin (E-cadherin) are considered as independent tumor markers in monitoring metastatic colorectal cancer. They are both expressed by cancer cells and can be detected in the blood serum. We investigated the effect of CEA production by MIP101 colorectal carcinoma cell lines on E-cadherin adherens junction (AJ) protein complexes. No direct interaction between E-cadherin and CEA was detected; however, the functional relationships between E-cadherin and its AJ partners: α-, β- and p120 catenins were impaired. We discovered a novel interaction between CEA and beta-catenin protein in the CEA producing cells. It is shown in the current study that CEA overexpression alters the splicing of p120 catenin and triggers the release of soluble E-cadherin. The influence of CEA production by colorectal cancer cells on the function of E-cadherin junction complexes may explain the link between the elevated levels of CEA and the increase in soluble E-cadherin during the progression of colorectal cancer. - Highlights: • Elevated level of CEA increases the release of soluble E-cadherin during the progression of colorectal cancer. • CEA over-expression alters the binding preferences between E-cadherin and its partners: α-, β- and p120 catenins in adherens junction complexes. • CEA produced by colorectal cancer cells interacts with beta-catenin protein. • CEA over-expression triggers the increase in nuclear beta-catenin. • CEA over-expression alters the splicing of p120 catenin protein.

  4. Matrix metalloproteinase-10 promotes tumor progression through regulation of angiogenic and apoptotic pathways in cervical tumors

    International Nuclear Information System (INIS)

    Cancer invasion and metastasis develops through a series of steps that involve the loss of cell to cell and cell to matrix adhesion, degradation of extracellular matrix and induction of angiogenesis. Different protease systems (e.g., matrix metalloproteinases, MMPs) are involved in these steps. MMP-10, one of the lesser studied MMPs, is limited to epithelial cells and can facilitate tumor cell invasion by targeting collagen, elastin and laminin. Enhanced MMP-10 expression has been linked to poor clinical prognosis in some cancers, however, mechanisms underlying a role for MMP-10 in tumorigenesis and progression remain largely unknown. Here, we report that MMP-10 expression is positively correlated with the invasiveness of human cervical and bladder cancers. Using commercial tissue microarray (TMA) of cervical and bladder tissues, MMP-10 immunohistochemical staining was performed. Furthermore using a panel of human cells (HeLa and UROtsa), in vitro and in vivo experiments were performed in which MMP-10 was overexpressed or silenced and we noted phenotypic and genotypic changes. Experimentally, we showed that MMP-10 can regulate tumor cell migration and invasion, and endothelial cell tube formation, and that MMP-10 effects are associated with a resistance to apoptosis. Further investigation revealed that increasing MMP-10 expression stimulates the expression of HIF-1α and MMP-2 (pro-angiogenic factors) and PAI-1 and CXCR2 (pro-metastatic factors), and accordingly, targeting MMP-10 with siRNA in vivo resulted in diminution of xenograft tumor growth with a concomitant reduction of angiogenesis and a stimulation of apoptosis. Taken together, our findings show that MMP-10 can play a significant role in tumor growth and progression, and that MMP-10 perturbation may represent a rational strategy for cancer treatment

  5. Foxp3 promoter polymorphism (rs3761548) in breast cancer progression: a study from India.

    Science.gov (United States)

    Jahan, Parveen; Ramachander, V R Vinish; Maruthi, G; Nalini, S; Latha, K Prasanna; Murthy, T S R

    2014-04-01

    Breast cancer is the most common female neoplasm that drives the transformation of normal mammary epithelial cells into highly malignant derivatives. Forkhead Box Protein3 (Foxp3), a tumor suppressor/immunomodulatory gene, which controls the function of Treg cells and oncogenes is down regulated in breast cancer. The main aim of the present study is to evaluate the potential influence of Foxp3-3279 C>A polymorphism (rs3761548) and -2383 C>T polymorphism (rs3761549) in 202 breast cancer patients and 130 normal healthy women of Indian origin. The genotypes were determined using ARMS-PCR for rs3761548 and PCR-RFLP method for rs3761549 using specific primers. The results revealed lack of association of these two polymorphisms with breast cancer susceptibility. However, with respect to AA genotype of rs3761548, we found highly significant association with the advanced stage (T3-4) of the tumor (OR = 3.90; 95% confidence interval (CI) = 1.56-9.70; p = 0.03). Stratified data also revealed an association of homozygous mutant genotype with advanced stage of tumor in premenopausal women (OR = 4.56; 95% CI = 1.07-19.38; p = 0.04) with disease duration of <6 months (OR =  .10; 95% CI = 1.80-20.50; p = 0.002) suggestive of modulating effect of rs3761548 in tumor progression. We conclude that Foxp3 rs37161548 has a potential to be a polymorphic marker for tumor progression in premenopausal breast cancer patients in Indian women. PMID:24338714

  6. Carcinoembryonic antigen promotes colorectal cancer progression by targeting adherens junction complexes

    International Nuclear Information System (INIS)

    Oncomarkers play important roles in the detection and management of human malignancies. Carcinoembryonic antigen (CEA, CEACAM5) and epithelial cadherin (E-cadherin) are considered as independent tumor markers in monitoring metastatic colorectal cancer. They are both expressed by cancer cells and can be detected in the blood serum. We investigated the effect of CEA production by MIP101 colorectal carcinoma cell lines on E-cadherin adherens junction (AJ) protein complexes. No direct interaction between E-cadherin and CEA was detected; however, the functional relationships between E-cadherin and its AJ partners: α-, β- and p120 catenins were impaired. We discovered a novel interaction between CEA and beta-catenin protein in the CEA producing cells. It is shown in the current study that CEA overexpression alters the splicing of p120 catenin and triggers the release of soluble E-cadherin. The influence of CEA production by colorectal cancer cells on the function of E-cadherin junction complexes may explain the link between the elevated levels of CEA and the increase in soluble E-cadherin during the progression of colorectal cancer. - Highlights: • Elevated level of CEA increases the release of soluble E-cadherin during the progression of colorectal cancer. • CEA over-expression alters the binding preferences between E-cadherin and its partners: α-, β- and p120 catenins in adherens junction complexes. • CEA produced by colorectal cancer cells interacts with beta-catenin protein. • CEA over-expression triggers the increase in nuclear beta-catenin. • CEA over-expression alters the splicing of p120 catenin protein

  7. Elevated serum alpha fetoprotein levels promote pathological progression of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Peng Li; Shan-Shan Wang; Hui Liu; Ning Li; Michael A McNutt; Gang Li; Hui-Guo Ding

    2011-01-01

    AIM: To investigate the biological role of alpha fetoprotein (AFP) and its clinical significance in carcinogenesis of hepatocellular carcinoma (HCC).METHODS: Clinical analysis of HCC patients and immunohistochemical examination were conducted to eva-luate the relationship between serum AFP level and patient mortality. Confocal microscopy, Western blotting, dimethylthiahzolyl-2,5-diphenyl-tetrazolium bromide, Cell Counting Kit-8 assays and flow cytometry were performed to explore the possible mechanism.RESULTS: Among the 160 HCC patients enrolled in this study, 130 patients survived 2 years (81.25%), with a survival rate of 86.8% in AFP 250 μg/L group, demonstrating a higher mortality rate in HCC patients with higher AFP levels. Surgical treatment was beneficial only in patients with low AFP levels. The mortality rate of HCC patients with high AFP levels who were treated surgically was apparently higher than those treated with conservative management. The results of immunohistochemistry showed that AFP and AFP receptor were merely expressed in tissues of HCC patients with positive serum AFP. Consistently, in vitro analysis showed that AFP and AFPS were expressed in HepG2 but not in HLE cells. AFP showed a capability to promote cell growth, and this was more apparent in HepG2 cells, in which the proliferation was increased by 3.5 folds. Cell cycle analysis showed that the percentage of HepG2 cells in S phase after exposure to AFP was modestly increased.CONCLUSION: HCC patients with higher AFP levels show a higher mortality rate, which appears to be attributable to the growth promoting properties of AFP.

  8. Understanding arsenic carcinogenicity by the use of animal models

    International Nuclear Information System (INIS)

    Although numerous epidemiological studies have indicated that human arsenic exposure is associated with increased incidences of bladder, liver, skin, and lung cancers, limited attempts have been made to understand mechanisms of carcinogenicity using animal models. Dimethylarsinic acid (DMA), an organic arsenic compound, is a major metabolite of ingested inorganic arsenics in mammals. Recent in vitro studies have proven DMA to be a potent clastogenic agent, capable of inducing DNA damage including double strand breaks and cross-link formation. In our attempts to clarify DMA carcinogenicity, we have recently shown carcinogenic effects of DMA and its related metabolites using various experimental protocols in rats and mice: (1) a multi-organ promotion bioassay in rats; (2) a two-stage promotion bioassay by DMA of rat urinary bladder and liver carcinogenesis; (3) a 2-year carcinogenicity test of DMA in rats; (4) studies on the effects of DMA on lung carcinogenesis in rats; (5) promotion of skin carcinogenesis by DMA in keratin (K6)/ornithine decarboxylase (ODC) transgenic mice; (6) carcinogenicity of DMA in p53(+/-) knockout and Mmh/8-OXOG-DNA glycolase (OGG1) mutant mice; (7) promoting effects of DMA and related organic arsenicals in rat liver; (8) promoting effects of DMA and related organic arsenicals in a rat multi-organ carcinogenesis test; and (9) 2-year carcinogenicity tests of monomethylarsonic acid (MMA) and trimethylarsine oxide (TMAO) in rats. The results revealed that the adverse effects of arsenic occurred either by promoting and initiating carcinogenesis. These data, as covered in the present review, suggest that several mechanisms may be involved in arsenic carcinogenesis

  9. PFTK1 Promotes Gastric Cancer Progression by Regulating Proliferation, Migration and Invasion.

    Directory of Open Access Journals (Sweden)

    Lei Yang

    Full Text Available PFTK1, also known as PFTAIRE1, CDK14, is a novel member of Cdc2-related serine/threonine protein kinases. Recent studies show that PFTK1 is highly expressed in several malignant tumors such as hepatocellular carcinoma, esophageal cancer, breast cancer, and involved in regulation of cell cycle, tumors proliferation, migration, and invasion that further influence the prognosis of tumors. However, the expression and physiological significance of PFTK1 in gastric cancer remain unclear. In this study, we analyzed the expression and clinical significance of PFTK1 by Western blot in 8 paired fresh gastric cancer tissues, nontumorous gastric mucosal tissues and immunohistochemistry on 161 paraffinembedded slices. High PFTK1 expression was correlated with the tumor grade, lymph node invasion as well as Ki-67. Through Cell Counting Kit (CCK-8 assay, flow cytometry, colony formation, wound healing and transwell assays, the vitro studies demonstrated that PFTK1 overexpression promoted proliferation, migration and invasion of gastric cancer cells, while PFTK1 knockdown led to the opposite results. Our findings for the first time supported that PFTK1 might play an important role in the regulation of gastric cancer proliferation, migration and would provide a novel promising therapeutic strategy against human gastric cancer.

  10. A health promotion logic model to review progress in HIV prevention in China.

    Science.gov (United States)

    Nutbeam, Don; Padmadas, Sabu S; Maslovskaya, Olga; Wu, Zhiwei

    2015-06-01

    Using the theory and concepts of health promotion, this paper proposes a logic model for HIV/AIDS prevention and control which provides a structure for describing planned actions and predicted impacts/outcomes from comprehensive HIV prevention interventions. The potential usefulness of the model is examined by reviewing the evolution of HIV prevention and management in China, drawing on evidence from interventions reported from a mixture of study designs and formats. It reports that HIV interventions in China can be considered in two distinctive phases, before and after 2003 when China commenced its 'official' response to the HIV epidemic. The logic model was useful in comparing actions taken over these two periods highlighting the importance of political leadership in distinguishing between the two phases, and the continuing importance of systematic and broadly based public education and communication. We conclude that the logic model can not only be used as a planning model, but can also be applied retrospectively to assess successes and failures in national and local responses to HIV in complex social settings. PMID:23753059

  11. OTX1 promotes colorectal cancer progression through epithelial-mesenchymal transition

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Kun; Cai, Xin-Yi; Li, Qiang; Yang, Zhi-Bin; Xiong, Wei; Shen, Tao; Wang, Wei-Ya; Li, Yun-Feng, E-mail: ynsliyunfeng@163.com

    2014-01-31

    Highlights: • OTX1 is overexpression in colorectal cancer tissues. • Overexpression of OTX1 promotes colorectal cancer cell proliferation and invasion in vitro and tumor growth in vivo. • Depletion of OTX1 inhibits colorectal cancer cell proliferation and invasion in vitro. • Overexpression of OTX1 is linked to the EMT-like phenotype. - Abstract: Orthodenticle homeobox 1 (OTX1), a transcription factor containing a bicoid-like homeodomain, plays a role in brain and sensory organ development. In this study, we report that OTX1 is overexpressed in human colorectal cancer (CRC) and OTX1 overexpression is associated with higher stage. Functional analyses reveal that overexpression of OTX1 results in accumulation of CRC cell proliferation and invasion in vitro and tumor growth in vivo, whereas ablation of OTX1 expression significantly inhibits the proliferative and invasive capability of CRC cells in vitro. Together, our results indicate that OTX1 is involved in human colon carcinogenesis and may serve as a potential therapeutic target for human colorectal cancer.

  12. OTX1 promotes colorectal cancer progression through epithelial-mesenchymal transition

    International Nuclear Information System (INIS)

    Highlights: • OTX1 is overexpression in colorectal cancer tissues. • Overexpression of OTX1 promotes colorectal cancer cell proliferation and invasion in vitro and tumor growth in vivo. • Depletion of OTX1 inhibits colorectal cancer cell proliferation and invasion in vitro. • Overexpression of OTX1 is linked to the EMT-like phenotype. - Abstract: Orthodenticle homeobox 1 (OTX1), a transcription factor containing a bicoid-like homeodomain, plays a role in brain and sensory organ development. In this study, we report that OTX1 is overexpressed in human colorectal cancer (CRC) and OTX1 overexpression is associated with higher stage. Functional analyses reveal that overexpression of OTX1 results in accumulation of CRC cell proliferation and invasion in vitro and tumor growth in vivo, whereas ablation of OTX1 expression significantly inhibits the proliferative and invasive capability of CRC cells in vitro. Together, our results indicate that OTX1 is involved in human colon carcinogenesis and may serve as a potential therapeutic target for human colorectal cancer

  13. PFTK1 Promotes Gastric Cancer Progression by Regulating Proliferation, Migration and Invasion.

    Science.gov (United States)

    Yang, Lei; Zhu, Jia; Huang, Hua; Yang, Qichang; Cai, Jing; Wang, Qiuhong; Zhu, Junya; Shao, Mengting; Xiao, Jinzhang; Cao, Jie; Gu, Xiaodan; Zhang, Shusen; Wang, Yingying

    2015-01-01

    PFTK1, also known as PFTAIRE1, CDK14, is a novel member of Cdc2-related serine/threonine protein kinases. Recent studies show that PFTK1 is highly expressed in several malignant tumors such as hepatocellular carcinoma, esophageal cancer, breast cancer, and involved in regulation of cell cycle, tumors proliferation, migration, and invasion that further influence the prognosis of tumors. However, the expression and physiological significance of PFTK1 in gastric cancer remain unclear. In this study, we analyzed the expression and clinical significance of PFTK1 by Western blot in 8 paired fresh gastric cancer tissues, nontumorous gastric mucosal tissues and immunohistochemistry on 161 paraffinembedded slices. High PFTK1 expression was correlated with the tumor grade, lymph node invasion as well as Ki-67. Through Cell Counting Kit (CCK)-8 assay, flow cytometry, colony formation, wound healing and transwell assays, the vitro studies demonstrated that PFTK1 overexpression promoted proliferation, migration and invasion of gastric cancer cells, while PFTK1 knockdown led to the opposite results. Our findings for the first time supported that PFTK1 might play an important role in the regulation of gastric cancer proliferation, migration and would provide a novel promising therapeutic strategy against human gastric cancer. PMID:26488471

  14. Fcp1 phosphatase controls Greatwall kinase to promote PP2A-B55 activation and mitotic progression

    Science.gov (United States)

    Della Monica, Rosa; Visconti, Roberta; Cervone, Nando; Serpico, Angela Flavia; Grieco, Domenico

    2015-01-01

    During cell division, progression through mitosis is driven by a protein phosphorylation wave. This wave namely depends on an activation-inactivation cycle of cyclin B-dependent kinase (Cdk) 1 while activities of major protein phosphatases, like PP1 and PP2A, appear directly or indirectly repressed by Cdk1. However, how Cdk1 inactivation is coordinated with reactivation of major phosphatases at mitosis exit still lacks substantial knowledge. We show here that activation of PP2A-B55, a major mitosis exit phosphatase, required the phosphatase Fcp1 downstream Cdk1 inactivation in human cells. During mitosis exit, Fcp1 bound Greatwall (Gwl), a Cdk1-stimulated kinase that phosphorylates Ensa/ARPP19 and converts these proteins into potent PP2A-B55 inhibitors during mitosis onset, and dephosphorylated it at Cdk1 phosphorylation sites. Fcp1-catalyzed dephosphorylation drastically reduced Gwl kinase activity towards Ensa/ARPP19 promoting PP2A-B55 activation. Thus, Fcp1 coordinates Cdk1 and Gwl inactivation to derepress PP2A-B55, generating a dephosphorylation switch that drives mitosis progression. DOI: http://dx.doi.org/10.7554/eLife.10399.001 PMID:26653855

  15. Identification of a Novel Membrane Transporter Mediating Resistance to Organic Arsenic in Campylobacter jejuni

    OpenAIRE

    Shen, Zhangqi; Luangtongkum, Taradon; Qiang, Zhiyi; Jeon, Byeonghwa; Wang, Liping; Zhang, Qijing

    2014-01-01

    Although bacterial mechanisms involved in the resistance to inorganic arsenic are well understood, the molecular basis for organic arsenic resistance has not been described. Campylobacter jejuni, a major food-borne pathogen causing gastroenteritis in humans, is highly prevalent in poultry and is reportedly resistant to the arsenic compound roxarsone (4-hydroxy-3-nitrobenzenearsonic acid), which has been used as a feed additive in the poultry industry for growth promotion. In this study, we re...

  16. Metastasis-inducing S100A4 and RANTES cooperate in promoting tumor progression in mice.

    Directory of Open Access Journals (Sweden)

    Birgitte Forst

    Full Text Available BACKGROUND: The tumor microenvironment has been described as a critical milieu determining tumor growth and metastases. A pivotal role of metastasis-inducing S100A4 in the development of tumor stroma has been proven in animal models and verified in human breast cancer biopsies. Expression and release of S100A4 has been shown in various types of stroma composing cells, including fibroblasts and immune cells. However, the events implicated in upstream and downstream pathways regulating the activity of the extracellular S100A4 protein in the tumor milieu remain unsolved. METHODOLOGY/PRINCIPAL FINDINGS: We studied the interplay between the tumor cell-derived cytokine regulated-upon-activation, normal T-cell expressed and secreted (RANTES; CCL5 and S100A4 which were shown to be critical factors in tumor progression. We found that RANTES stimulates the externalization of S100A4 via microparticle shedding from the plasma membrane of tumor and stroma cells. Conversely, the released S100A4 protein induces the upregulation of fibronectin (FN in fibroblasts and a number of cytokines, including RANTES in tumor cells as well as stimulates cell motility in a wound healing assay. Importantly, using wild type and S100A4-deficient mouse models, we demonstrated a substantial influence of tumor cell-derived RANTES on S100A4 release into blood circulation which ultimately increases the metastatic burden in mice. CONCLUSIONS/SIGNIFICANCE: Altogether, the data presented strongly validate the pro-metastatic function of S100A4 in the tumor microenvironment and define how the tumor cell-derived cytokine RANTES acts as a critical regulator of S100A4-dependent tumor cell dissemination. Additionally, for the first time we demonstrated the mechanism of S100A4 release associated with plasma membrane microparticle shedding from various cells types.

  17. Fibroblast-derived MT1-MMP promotes tumor progression in vitro and in vivo

    International Nuclear Information System (INIS)

    Identification of fibroblast derived factors in tumor progression has the potential to provide novel molecular targets for modulating tumor cell growth and metastasis. Multiple matrix metalloproteases (MMPs) are expressed by both mesenchymal and epithelial cells within head and neck squamous cell carcinomas (HNSCCs), but the relative importance of these enzymes and the cell source is the subject of controversy. The invasive potential of HNSCC tumor cells were assessed in vitro atop type I collagen gels in coculture with wild-type (WT), MMP-2 null, MMP-9 null or MT1-MMP null fibroblasts. A floor of mouth mouse model of HNSCC was used to assess in vivo growth after co-injection of FaDu tumor cells with MMP null fibroblasts. Here we report changes in tumor phenotype when FaDu HNSCCs cells are cocultured with WT, MMP-2 null, MMP-9 null or MT1-MMP null fibroblasts in vitro and in vivo. WT, MMP-2 null and MMP-9 null fibroblasts, but not MT1-MMP null fibroblasts, spontaneously invaded into type I collagen gels. WT fibroblasts stimulated FaDu tumor cell invasion in coculture. This invasive phenotype was unaffected by combination with MMP-9 null fibroblasts, reduced with MMP-2 null fibroblasts (50%) and abrogated in MT1-MMP null fibroblasts. Co-injection of FaDu tumor cells with fibroblasts in an orthotopic oral cavity SCID mouse model demonstrated a reduction of tumor volume using MMP-9 and MMP-2 null fibroblasts (48% and 49%, respectively) compared to WT fibroblasts. Consistent with in vitro studies, MT1-MMP null fibroblasts when co-injected with FaDu cells resulted in a 90% reduction in tumor volume compared to FaDu cells injected with WT fibroblasts. These data suggest a role for fibroblast-derived MMP-2 and MT1-MMP in HNSCC tumor invasion in vitro and tumor growth in vivo

  18. Selection, de-selection and progression in German football talent promotion.

    Science.gov (United States)

    Güllich, Arne

    2014-01-01

    This study explored to which extent the development of German professional football players is based on early talent identification (TID) and long-term nurture in talent promotion (TP) programmes or on their emergence in the course of repeated procedures of player selection and de-selection in these programmes through childhood and youth. The annual turnover of squad members in national junior teams (2001-2013) and youth elite academies was calculated; national U-team members were followed up with regard to nominations through subsequent seasons and to their success level eventually achieved at senior age; and all current Bundesliga players were analysed retrospectively regarding their earlier involvement in TID/TP programmes. Analyses revealed that the mean annual turnover of squad members was 24.5% (youth academies) and 41.0% (national U-teams), respectively. At any age, the probability of persisting in the programme three years later was <50%. Among current Bundesliga players, the age of recruitment into the TID/TP programme was widely evenly distributed across childhood and youth, respectively. Accordingly, the number of (future) Bundesliga players who were involved in TID/TP was built up continuously through all age categories. The observations suggest that the collective of professional players emerged from repeated procedures of selection and de-selection through childhood and youth rather than from early selection and long-term continuous nurture in TID/TP programmes. The findings are discussed with regard to the uncertainty of TID and of interventions applied to the selected players, and they are related to the individualistic and collectivistic approach in TP. PMID:24245783

  19. Fibroblast growth factor receptor 4 promotes progression and correlates to poor prognosis in cholangiocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yun-Fei [Department of Hepatobiliary Surgery, Qilu Hospital of Shandong University (China); Yang, Xiao-Qing [Department of Pathology, Shandong University (China); Lu, Xiao-Fei [Department of Gastrointestinal Surgery, Jinan Central Hospital (China); Guo, Sen; Liu, Yi; Iqbal, Mohammad; Ning, Shang-Lei; Yang, Hui [Department of Hepatobiliary Surgery, Qilu Hospital of Shandong University (China); Suo, Ning [Department of Anatomy, Shandong University (China); Chen, Yu-Xin, E-mail: yxu8@bidmc.harvard.edu [Department of Hepatobiliary Surgery, Qilu Hospital of Shandong University (China)

    2014-03-28

    Highlights: • FGFR4 is significantly related with N stage in IHCC, with T stage and TNM stage in PHCC. • FGFR4 is an independent prognostic factor in IHCC and PHCC. • FGFR4 promotes proliferation, invasion and EMT in cholangiocarinoma cell lines. • Inhibitor AP24354 can decrease proliferation, invasion and induce apoptosis of CCA. - Abstract: Fibroblast growth factor receptor 4 (FGFR4) is related to poor prognosis of several cancers, but the correlation between FGFR4 expression and cholangiocarcinoma (CCA) has not been well elucidated. We investigated the expression of FGFR4 in 83 intrahepatic cholangiocarcinomas (IHCCs), 75 perihilar cholangiocarcinomas (PHCCs) and 41 distal cholangiocarcinomas (DCCs) by immunohistochemistry (IHC), and subsequently evaluated association of FGFR4 with clinicopathologic parameters and survival rate. The rate of FGFR4 higher expression was 61.4% (51/83) in IHCCs, 53.3% (40/75) in PHCCs and 56.1% (23/41) in DCCs. FGFR4 expression was significantly related to poor prognosis of IHCC (P = 0.002) and PHCC (P = 0.019) with univariate analysis, and also identified as an independent prognostic factor in IHCC (P = 0.045) and PHCC (P = 0.049) with multivariate analysis. Additionally, with functional assays in vitro, we found FGFR4 can induce proliferation, invasion and epithelial–mesenchymal transition (EMT) of CCA cell lines with FGF19 stimulation. Moreover, FGFR4 inhibitor AP24354 can suppress proliferation, invasion and induce apoptosis of CCA cells. In conclusion, FGFR4 expression can be identified as a significant independent prognostic biomarker of IHCC and PHCC. FGFR4 played a pivotal role in proliferation, invasion and EMT of CCA. FGFR4 inhibitor can suppress proliferation, invasion and induce apoptosis of CCA, indicating that FGFR4 may act as a potential therapeutic target.

  20. Fibroblast growth factor receptor 4 promotes progression and correlates to poor prognosis in cholangiocarcinoma

    International Nuclear Information System (INIS)

    Highlights: • FGFR4 is significantly related with N stage in IHCC, with T stage and TNM stage in PHCC. • FGFR4 is an independent prognostic factor in IHCC and PHCC. • FGFR4 promotes proliferation, invasion and EMT in cholangiocarinoma cell lines. • Inhibitor AP24354 can decrease proliferation, invasion and induce apoptosis of CCA. - Abstract: Fibroblast growth factor receptor 4 (FGFR4) is related to poor prognosis of several cancers, but the correlation between FGFR4 expression and cholangiocarcinoma (CCA) has not been well elucidated. We investigated the expression of FGFR4 in 83 intrahepatic cholangiocarcinomas (IHCCs), 75 perihilar cholangiocarcinomas (PHCCs) and 41 distal cholangiocarcinomas (DCCs) by immunohistochemistry (IHC), and subsequently evaluated association of FGFR4 with clinicopathologic parameters and survival rate. The rate of FGFR4 higher expression was 61.4% (51/83) in IHCCs, 53.3% (40/75) in PHCCs and 56.1% (23/41) in DCCs. FGFR4 expression was significantly related to poor prognosis of IHCC (P = 0.002) and PHCC (P = 0.019) with univariate analysis, and also identified as an independent prognostic factor in IHCC (P = 0.045) and PHCC (P = 0.049) with multivariate analysis. Additionally, with functional assays in vitro, we found FGFR4 can induce proliferation, invasion and epithelial–mesenchymal transition (EMT) of CCA cell lines with FGF19 stimulation. Moreover, FGFR4 inhibitor AP24354 can suppress proliferation, invasion and induce apoptosis of CCA cells. In conclusion, FGFR4 expression can be identified as a significant independent prognostic biomarker of IHCC and PHCC. FGFR4 played a pivotal role in proliferation, invasion and EMT of CCA. FGFR4 inhibitor can suppress proliferation, invasion and induce apoptosis of CCA, indicating that FGFR4 may act as a potential therapeutic target

  1. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

    Directory of Open Access Journals (Sweden)

    Robin B. Harris

    2012-03-01

    Full Text Available The Binational Arsenic Exposure Survey (BAsES was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001, urinary inorganic arsenic concentration (p < 0.001, and urinary sum of species (p < 0.001. Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

  2. Arsenite-oxidizing bacteria exhibiting plant growth promoting traits isolated from the rhizosphere of Oryza sativa L.: Implications for mitigation of arsenic contamination in paddies.

    Science.gov (United States)

    Das, Suvendu; Jean, Jiin-Shuh; Chou, Mon-Lin; Rathod, Jagat; Liu, Chia-Chuan

    2016-01-25

    Arsenite-oxidizing bacteria exhibiting plant growth promoting (PGP) traits can have the advantages of reducing As-uptake by rice and promoting plant growth in As-stressed soil. A gram-positive bacterium Bacillus flexus ASO-6 resistant to high levels of As (32 and 280 mM for arsenite and arsenate, respectively) and exhibiting elevated rates of As(III) oxidation (Vmax=1.34 μM min(-1) 10(-7) cell) was isolated from rhizosphere of rice. The presence of aoxB gene and exhibition of As(III)-oxidase enzyme activity of this strain was observed. The ability of the strain to produce siderophore, IAA, ACC-deaminase and to solubilize phosphate was verified. The rice seed treated with the strain exhibited significantly improved seed germination and seedling vigor compared with the un-inoculated seeds. The bacterial inoculation significantly increased root biomass, straw yield, grain yield, chlorophyll and carotenoid in the rice plant. Moreover, As uptake from root to shoot and As accumulation in straw and grain decreased significantly as a result of the bacterial inoculation. Noteworthy, the inoculation effect is more prominent in non-flooded soil than it is in flooded soil. Owing to its wide action spectrum, this As(III)-oxidizing PGPB could serve as a potential bio-inoculant for mitigation of As in paddies and sustainable rice production in As-contaminated areas. PMID:26448489

  3. Association of promoter methylation of VGF and PGP9.5 with ovarian cancer progression.

    Directory of Open Access Journals (Sweden)

    Mariana Brait

    Full Text Available PURPOSE: To elucidate the role of biological and clinical impact of aberrant promoter hypermethylation (PH in ovarian cancer (OC. EXPERIMENTAL DESIGN: PH of PGP9.5, HIC1, AIM1, APC, PAK3, MGMT, KIF1A, CCNA1, ESR1, SSBP2, GSTP1, FKBP4 and VGF were assessed by quantitative methylation specific PCR (QMSP in a training set. We selected two genes (VGF and PGP9.5 for further QMSP analysis in a larger independent validation (IV set with available clinical data. Biologic relevance of VGF gene was also evaluated. RESULTS: PH frequency for PGP9.5 and VGF were 85% (316/372 and 43% (158/366 respectively in the IV set of samples while no PH was observed in controls. In 372 OC cases with available follow up, PGP9.5 and VGF PH were correlated with better patient survival [Hazard Ratios (HR for overall survival (OS were 0.59 (95% Confidence Intervals (CI  = 0.42-0.84, p = 0.004, and 0.73 (95%CI = 0.55-0.97, p = 0.028 respectively, and for disease specific survival (DSS were 0.57 (95%CI 0.39-0.82, p = 0.003 and 0.72 (95%CI 0.54-0.96, p = 0.027. In multivariate analysis, VGF PH remained an independent prognostic factor for OS (HR 0.61, 95%CI 0.43-0.86, p<0.005 and DSS (HR 0.58, 95%CI 0.41-0.83, p<0.003. Furthermore, PGP9.5 PH was significantly correlated with lower grade, early stage tumors, and with absence of residual disease. Forced expression of VGF in OC cell lines inhibited cell growth. CONCLUSIONS: Our results indicate that VGF and PGP9.5 PH are potential biomarkers for ovarian carcinoma. Confirmatory cohorts with longitudinal follow-up are required in future studies to define the clinical impact of VGF and PGP9.5 PH before clinical application.

  4. USEPA Arsenic Demonstration Program

    Science.gov (United States)

    The presentation provides background information on the USEPA arsenic removal program. The summary includes information on the history of the program, sites and technology selected, and a summary of the data collected from two completed projects.

  5. Expression of Heterogenous Arsenic Resistance Genes in the Obligately Autotrophic Biomining Bacterium Thiobacillus ferrooxidans

    OpenAIRE

    Peng, Ji-Bin; Yan, Wang-Ming; Bao, Xue-Zhen

    1994-01-01

    Two arsenic-resistant plasmids were constructed and introduced into Thiobacillus ferrooxidans strains by conjugation. The plasmids with the replicon of wide-host-range plasmid RSF1010 were stable in T. ferrooxidans. The arsenic resistance genes originating from the heterotroph were expressed in this obligately autotrophic bacterium, but the promoter derived from T. ferrooxidans showed no special function in its original host.

  6. EXAFS study on arsenic species and transformation in arsenic hyperaccumulator

    Institute of Scientific and Technical Information of China (English)

    HUANG Zechun; CHEN Tongbin; LEI Mei; HU Tiandou; HUANG Qifei

    2004-01-01

    Synchrotron radiation extended X-ray absorption fine structure (SR EXAFS) was employed to study the transformation of coordination environment and the redox speciation of arsenic in a newly discovered arsenic hyperaccumulator, Cretan brake (Pteris cretica L. var nervosa Thunb). It showed that the arsenic in the plant mainly coordinated with oxygen, except that some arsenic coordinated with S as As-GSH in root. The complexation of arsenic with GSH might not be the predominant detoxification mechanism in Cretan brake. Although some arsenic in root presented as As(V) in Na2HAsO4 treatments, most of arsenic in plant presented as As(III)-O in both treatments, indicating that As(V) tended to be reduced to As(III) after it was taken up into the root, and arsenic was kept as As(III) when it was transported to the above-ground tissues. The reduction of As(V) primarily proceeded in the root.

  7. Spectral reflectance as an indicator of foliar concentrations of arsenic in common sunflower (Helianthus annuus)

    Science.gov (United States)

    Gandy, Yuridia Patricia Peralta De

    Studies were conducted to investigate the use of spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination of soil. Germination method was developed for sunflower seeds, and cohorts of sunflower seedlings in hydroponic tanks were established. The cohorts were exposed to 0 ppm, 5 ppm, 7.5 ppm, and 10 ppm treatments of As (V) and reflectance measurements of foliage were collected using a spectroradiometer during two experiments. Results demonstrated the feasibility of using spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination. In both experiments, arsenic concentrations in leaf tissues were directly proportional to arsenic concentrations in hydroponic solutions in which such plants were grown. Although the effect(s) of arsenic accumulation had minimal impact on reflectance of visible wavelengths, the effects on NIR reflectance were substantial and resulted in a progressive decrease in reflectance as arsenic concentrations in foliage increased.

  8. Effectiveness of progressive muscle relaxation therapy as a worksite health promotion program in the automobile assembly line.

    Science.gov (United States)

    Sundram, Bala Murali; Dahlui, Maznah; Chinna, Karuthan

    2016-06-10

    The aim of this study was to examine the effectiveness of Progressive Muscle Relaxation (PMR) as part of a Worksite Health Promotion Program on self-perceived stress, anxiety and depression among male automotive assembly-line workers through a quasi-experimental trial. Two assembly plants were chosen with one receiving PMR therapy and the other Pamphlets. Intention-to-treat analysis was conducted to test the effectiveness of the relaxation therapy. Stress, Depression and Anxiety levels were measured using the shortened DASS-21 questionnaire. Data were analyzed using Chi-square, Independent sample t test and Repeated-measures analysis of variance to test the significance of the effects of intervention (time * group) for the measures of Stress, Depression and Anxiety. Significant favourable intervention effects on stress were found in the PMR group (Effect size=0.6) as compared to the Pamphlet group (Effect size=0.2). There was a significant group *time interaction effect (p<0.001) on Stress levels. Depression and Anxiety levels were minimal at baseline in both the groups with mild or no reduction in levels. The improvement in stress levels showed the potential of PMR therapy as a coping strategy at the workplace. Further research in this field is necessary to examine the beneficial effects of coping strategies in the workplace. PMID:26726829

  9. Acute and chronic arsenic toxicity

    OpenAIRE

    Ratnaike, R.

    2003-01-01

    Arsenic toxicity is a global health problem affecting many millions of people. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial processes. Arsenic is present as a contaminant in many traditional remedies. Arsenic trioxide is now used to treat acute promyelocytic leukaemia. Absorption occurs predominantly from ingestion from the small intestine, though minimal absorption o...

  10. Atherosclerosis induced by arsenic in drinking water in rats through altering lipid metabolism

    International Nuclear Information System (INIS)

    Arsenic in drinking water is a global environmental health problem, and the exposure may increase cardiovascular and cerebrovascular diseases mortalities, most likely through causing atherosclerosis. However, the mechanism of atherosclerosis formation after arsenic exposure is still unclear. To study the mechanism of atherosclerosis formation after arsenic exposure and explore the role of high cholesterol diet (HCD) in this process, we fed spontaneous hypertensive rats and Wistar Kyoto rats with basal diet or HCD and provided with them drinking water containing arsenic at different ages and orders for 20 consecutive weeks. We measured high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, heat shock protein 70 (HSP 70), and high sensitive C-reactive protein (hs-CRP) at predetermined intervals and determined expressions of cholesteryl ester transfer protein-1 (CETP-1) and liver X receptor β (LXRβ) in the liver. Atherosclerosis was determined by examining the aorta with hematoxylin and eosin stain. After 20 weeks, we found arsenic, alone or combined with HCD, may promote atherosclerosis formation with transient increases in HSP 70 and hs-CRP. Early combination exposure decreased the HDL-C/LDL-C ratio without changing the levels of total cholesterol and triglyceride until 30 weeks old. Both CETP-1 and LXRβ activities were suppressed, most significantly in early combination exposure. In conclusion, arsenic exposure may induce atherosclerosis through modifying reverse cholesterol transport in cholesterol metabolism and suppressing LXRβ and CEPT-1 expressions. For decreasing atherosclerosis related mortality associated with arsenic, preventing exposure from environmental sources in early life is an important element. - Highlights: → Arsenic causes cardiovascular and cerebrovascular diseases through atherosclerosis. → Arsenic may promote atherosclerosis with transient increase in HSP 70 and hs

  11. Arsenic (+3 oxidation state) methyltransferase and the methylation of arsenicals in the invertebrate chordate Ciona intestinalis

    Science.gov (United States)

    Biotransformation of inorganic arsenic (iAs) involves methylation catalyzed by arsenic (+3 oxidation state) methyltransferase (As3mt), yielding mono- , di- , and trimethylated arsenicals. To investigate the evolution of molecular mechanisms that mediate arsenic biotransformation,...

  12. Arsenic: The Silent Killer

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Andrea (USGS)

    2006-02-28

    Andrea Foster uses x-rays to determine the forms of potentially toxic elements in environmentally-important matrices such as water, sediments, plants, and microorganisms. In this free public lecture, Foster will discuss her research on arsenic, which is called the silent killer because dissolved in water, it is colorless, odorless, and tasteless, yet consumption of relatively small doses of this element in its most toxic forms can cause rapid and violent death. Arsenic is a well-known poison, and has been used as such since ancient times. Less well known is the fact that much lower doses of the element, consumed over years, can lead to a variety of skin and internal cancers that can also be fatal. Currently, what has been called the largest mass poisoning in history is occurring in Bangladesh, where most people are by necessity drinking ground water that is contaminated with arsenic far in excess of the maximum amounts determined to be safe by the World Health Organization. This presentation will review the long and complicated history with arsenic, describe how x-rays have helped explain the high yet spatially variable arsenic concentrations in Bangladesh, discuss the ways in which land use in Bangladesh may be exacerbating the problem, and summarize the impact of this silent killer on drinking water systems worldwide.

  13. Arsenic hyperaccumulator Pteris Vittata L. and its arsenic accumulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An arsenic hyperaccumulator Pteris vittata L. (Chinese brake) was first discovered in China by means of field survey and greenhouse cultivation. Field survey showed that Chinese brake had large accumulating capacity to arsenic; the orders of arsenic content in different parts of the fern were as follows: leaves>leafstalks>roots, which is totally different from that of ordinary plants; bioaccumulation coefficients of the above ground parts of the fern decreased as a power function of soil arsenic contents. In the control of pot trials with normal unpolluted soil containing 9 mg/kg of arsenic, the bioaccumulation coefficients of the above ground parts and rhizoids of Chinese brake were as high as 71 and 80 respectively. Greenhouse cultivation in the contaminated soil from mining areas has shown that more than 1 times greater arsenic can be accumulated in the leaves of the fern than that of field samples with the largest content of 5070 mg/kg As on a dry matter basis. During greenhouse cultivation, arsenic content in the leaves of the fern increased linearly with time prolonging. Not only has Chinese brake extraordinary tolerance and accumulation to arsenic, but it grew rapidly with great biomass, wide distribution and easy adaptation to different environmental conditions as well. Therefore, it has great potential in future remediation of arsenic contamination. It also demonstrates important value for studies of arsenic physiology and biochemistry such as arsenic absorption, translocation and detoxification mechanisms in plants.

  14. Ras and TGF-β signaling enhance cancer progression by promoting the ΔNp63 transcriptional program.

    Science.gov (United States)

    Vasilaki, Eleftheria; Morikawa, Masato; Koinuma, Daizo; Mizutani, Anna; Hirano, Yudai; Ehata, Shogo; Sundqvist, Anders; Kawasaki, Natsumi; Cedervall, Jessica; Olsson, Anna-Karin; Aburatani, Hiroyuki; Moustakas, Aristidis; Miyazono, Kohei; Heldin, Carl-Henrik

    2016-01-01

    The p53 family of transcription factors includes p63, which is a master regulator of gene expression in epithelial cells. Determining whether p63 is tumor-suppressive or tumorigenic is complicated by isoform-specific and cellular context-dependent protein associations, as well as antagonism from mutant p53. ΔNp63 is an amino-terminal-truncated isoform, that is, the predominant isoform expressed in cancer cells of epithelial origin. In HaCaT keratinocytes, which have mutant p53 and ΔNp63, we found that mutant p53 antagonized ΔNp63 transcriptional activity but that activation of Ras or transforming growth factor-β (TGF-β) signaling pathways reduced the abundance of mutant p53 and strengthened target gene binding and activity of ΔNp63. Among the products of ΔNp63-induced genes was dual-specificity phosphatase 6 (DUSP6), which promoted the degradation of mutant p53, likely by dephosphorylating p53. Knocking down all forms of p63 or DUSP6 and DUSP7 (DUSP6/7) inhibited the basal or TGF-β-induced or epidermal growth factor (which activates Ras)-induced migration and invasion in cultures of p53-mutant breast cancer and squamous skin cancer cells. Alternatively, overexpressing ΔNp63 in the breast cancer cells increased their capacity to colonize various tissues upon intracardiac injection in mice, and this was inhibited by knocking down DUSP6/7 in these ΔNp63-overexpressing cells. High abundance of ΔNp63 in various tumors correlated with poor prognosis in patients, and this correlation was stronger in patients whose tumors also had a mutation in the gene encoding p53. Thus, oncogenic Ras and TGF-β signaling stimulate cancer progression through activation of the ΔNp63 transcriptional program. PMID:27555661

  15. Specific disruption of Tsc1 in ovarian granulosa cells promotes ovulation and causes progressive accumulation of corpora lutea.

    Directory of Open Access Journals (Sweden)

    Lin Huang

    Full Text Available Tuberous sclerosis complex 1 (Tsc1 is a tumor suppressor negatively regulating mammalian target of rapamycin complex 1 (mTORC1. It is reported that mice lacking Tsc1 gene in oocytes show depletion of primordial follicles, resulting in premature ovarian failure and subsequent infertility. A recent study indicated that deletion of Tsc1 in somatic cells of the reproductive tract caused infertility of female mice. However, it is not known whether specific disruption of Tsc1 in granulosa cells influences the reproductive activity of female mice. To clarify this problem, we mated Tsc1(flox/flox mice with transgenic mice strain expressing cyp19-cre which exclusively expresses in granulosa cells of the ovary. Our results demonstrated that Tsc1(flox/flox; cyp19-cre mutant mice were fertile, ovulating more oocytes and giving birth to more pups than control Tsc1(flox/flox mice. Progressive accumulation of corpora lutea occurred in the Tsc1(flox/flox; cyp19-cre mutant mice with advanced age. These phenotypes could be explained by the elevated activity of mTORC1, as indicated by increased phosphorylation of rpS6, a substrate of S6 in the Tsc1(flox/flox; cyp19-cre mutant granulosa cells. In addition, rapamycin, a specific mTORC1 inhibitor, effectively rescued the phenotype caused by increased mTORC1 activity in the Tsc1(cko ovaries. Our data suggest that conditional knockout of Tsc1 in granulosa cells promotes reproductive activity in mice.

  16. Arsenic Speciation of Terrestrial Invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, M.M.; Koch, I.; Gordon, R.A.; Reimer, K.J. ((Simon)); ((Royal))

    2009-07-01

    The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine sites and one background site in Nova Scotia, Canada. Total arsenic concentrations, determined by inductively coupled plasma mass spectrometry (ICP-MS), were dependent upon the classification of invertebrate. Arsenic species were determined by high-performance liquid chromatography (HPLC) ICP-MS and X-ray absorption spectroscopy (XAS). Invertebrates were found by HPLC ICP-MS to contain predominantly arsenite and arsenate in methanol/water extracts, while XAS revealed that most arsenic is bound to sulfur in vivo. Examination of the spatial distribution of arsenic within an ant tissue highlighted the differences between exogenous and endogenous arsenic, as well as the extent to which arsenic is transformed upon ingestion. Similar arsenic speciation patterns for invertebrate groups were observed across sites. Trace amounts of arsenobetaine and arsenocholine were identified in slugs, ants, and spiders.

  17. ARSENIC REMOVAL TREATMENT OPTIONS FOR SINGLE FAMILY HOMES

    Science.gov (United States)

    The presentation provides information on POU and POE arsenic removal drinking water treatment systems. The presentation provides information on the arsenic rule, arsenic chemistry and arsenic treatment. The arsenic treatment options proposed for POU and POE treatment consist prim...

  18. Arsenic Trioxide Modulates DNA Synthesis and Apoptosis in Lung Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Kenneth Ndebele

    2010-04-01

    Full Text Available Arsenic trioxide, the trade name Trisenox, is a drug used to treat acute promyleocytic leukemia (APL. Studies have demonstrated that arsenic trioxide slows cancer cells growth. Although arsenic influences numerous signal-transduction pathways, cell-cycle progression, and/or apoptosis, its apoptotic mechanisms are complex and not entirely delineated. The primary objective of this research was to evaluate the effects of arsenic trioxide on DNA synthesis and to determine whether arsenic-induced apoptosis is mediated via caspase activation, p38 mitogen–activated protein kinase (MAPK, and cell cycle arrest. To achieve this goal, lung cancer cells (A549 were exposed to various concentrations (0, 2, 4, 6, 8, and 10 µg/mL of arsenic trioxide for 48 h. The effect of arsenic trioxide on DNA synthesis was determined by the [3H]thymidine incorporation assay. Apoptosis was determined by the caspase-3 fluorescein isothiocyanate (FITC assay, p38 MAP kinase activity was determined by an immunoblot assay, and cell-cycle analysis was evaluated by the propidium iodide assay. The [3H]thymidine-incorporation assay revealed a dose-related cytotoxic response at high levels of exposure. Furthermore, arsenic trioxide modulated caspase 3 activity and induced p38 MAP kinase activation in A549 cells. However, cell-cycle studies showed no statistically significant differences in DNA content at subG1 check point between control and arsenic trioxide treated cells.

  19. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Science.gov (United States)

    Xie, Zuoming; Wang, Yanxin; Duan, Mengyu; Xie, Xianjun; Su, Chunli

    2011-03-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus ( B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined. Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH, Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

  20. P01.23NEUROTENSIN PROMOTES THE PROGRESSION OF MALIGNANT GLIOMA THROUGH NTSR1 AND IMPACTS THE PROGNOSIS OF GLIOMA PATIENTS

    OpenAIRE

    Yi, L.; Xu, M.; Xu, L.; Feng, H.; Cui, H.

    2014-01-01

    BACKGROUND: Neurotensin (NTS) functions as a neuromodulator and induces cellular proliferation and migration in various solid tumors. However, whether NTS can promote the progression of malignant glioma and its prognostic significance for glioma patients remain unclear. METHODS: NTS and its high-affinity receptor (NTSR1) expression levels in clinical glioma samples were detected by immunohistochemistry and immunobloting. The prognostic analysis in glioma patients were conducted online by R2 m...

  1. Understanding arsenic contamination of groundwater in Bangladesh

    International Nuclear Information System (INIS)

    least) the operation and maintenance of the system. The arsenic 'crisis' has taught that the use of groundwater for water supply - and for that matter also agricultural irrigation - needs much more thorough scrutiny with respect to its chemical composition. In general, if arsenic now has proved to be more widely present in groundwater than originally thought, and if it has such dramatic health effects that occur after long-term ingestion, then other low-concentration elements in groundwater may equally be a cause or a factor in other disease patterns. This requires simpler techniques to determine water quality of different aquifers and the long-term safety of these aquifers. Isotope hydrology has proved to be a good tool in Bangladesh to identify source of water in different aquifers. Water quality dimensions are often absent in ongoing efforts to clarify, codify, and implement the policy, legal and institutional dimensions to promote groundwater use for economic and social development, particularly in the developing world. Moreover, past water and sanitation projects financed by the World Bank and other donor agencies have rarely included a systematic consideration of groundwater quality issues. Our belief is that some of these issues require urgent attention - such as the need to immediately include and implement the systematic analysis of groundwater quality in the environmental analysis of development efforts with a groundwater component or impact

  2. Reactive oxygen species mediate arsenic induced cell transformation and tumorigenesis through Wnt/β-catenin pathway in human colorectal adenocarcinoma DLD1 cells

    International Nuclear Information System (INIS)

    Long term exposure to arsenic can increase incidence of human cancers, such as skin, lung, and colon rectum. The mechanism of arsenic induced carcinogenesis is still unclear. It is generally believed that reactive oxygen species (ROS) may play an important role in this process. In the present study, we investigate the possible linkage between ROS, β-catenin and arsenic induced transformation and tumorigenesis in human colorectal adenocarcinoma cell line, DLD1 cells. Our results show that arsenic was able to activate p47phox and p67phox, two key proteins for activation of NADPH oxidase. Arsenic was also able to generate ROS in DLD1 cells. Arsenic increased β-catenin expression level and its promoter activity. ROS played a major role in arsenic-induced β-catenin activation. Treatment of DLD1 cells by arsenic enhanced both transformation and tumorigenesis of these cells. The tumor volumes of arsenic treated group were much larger than those without arsenic treatment. Addition of either superoxide dismutase (SOD) or catalase reduced arsenic induced cell transformation and tumor formation. The results indicate that ROS are involved in arsenic induced cell transformation and tumor formation possible through Wnt/β-catenin pathway in human colorectal adenocarcinoma cell line DLD1 cells. - Highlights: → Arsenic activates NADPH oxidase and increases reactive oxygen species generation in DLD1 cells. → Arsenic increases β-catenin expression. → Inhibition of ROS induced by arsenic reduce β-catenin expression. → Arsenic increases cell transformation in DLD1 cells and tumorigenesis in nude mice. → Blockage of ROS decrease cell transformation and tumorigenesis induced by arsenic.

  3. Rural methods to mitigate arsenic contaminated water

    OpenAIRE

    Parajuli, Krishna

    2013-01-01

    Consumption of arsenic contaminated water is one of the burning issues in the rural world. Poor public awareness program about health effects of drinking arsenic contaminated water and the rural methods to mitigate this problem poses a great threat of arsenic poisoning many people of the rural world. In this thesis, arsenic removal efficiency and the working mechanism of four rural and economical arsenic mitigation technologies i.e. solar oxidation and reduction of arsenic (SORAS), Bucket tr...

  4. Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/β-catenin signaling pathway

    OpenAIRE

    Wang, Xin; Mandal, Ardhendu K.; Saito, Hiroshi; Pulliam, Joseph F.; Lee, Eun Y.; Ke, Zun-Ji; Lu, Jian; Ding, Songze; Li, Li; Shelton, Brent J.; Tucker, Thomas; Evers, B. Mark; Zhang, Zhuo; Shi, Xianglin

    2012-01-01

    Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alon...

  5. Arsenic-induced Aurora-A activation contributes to chromosome instability and tumorigenesis

    Science.gov (United States)

    Wu, Chin-Han; Tseng, Ya-Shih; Yang, Chao-Chun; Kao, Yu-Ting; Sheu, Hamm-Ming; Liu, Hsiao-Sheng

    2013-11-01

    Arsenic may cause serious environmental pollution and is a serious industrial problem. Depending on the dosage, arsenic may trigger the cells undergoing either proliferation or apoptosis-related cell death. Because of lack of the proper animal model to study arsenic induced tumorigenesis, the accurate risk level of arsenic exposure has not been determined. Arsenic shows genotoxic effect on human beings who uptake water contaminated by arsenic. Chromosome aberration is frequently detected in arsenic exposure-related diseases and is associated with increased oxidative stress and decreased DNA repairing activity, but the underlying mechanism remains elusive. Aurora-A is a mitotic kinase, over-expression of Aurora-A leads to centrosome amplification, chromosomal instability and cell transformation. We revealed that Aurora-A is over-expressed in the skin and bladder cancer patients from blackfoot-disease endemic areas. Our cell line studies reveal that arsenic exposure between 0.5 μM and 1 μM for 2-7 days are able to induce Aurora-A expression and activation based on promoter activity, RNA and protein analysis. Aurora-A overexpression further increases the frequency of unsymmetrical chromosome segregation through centrosome amplification followed by cell population accumulated at S phase in immortalized keratinocyte (HaCaT) and uroepithelial cells (E7). Furthermore, Aurora-A over-expression was sustained for 1-4 weeks by chronic treatment of immortalized bladder and skin cells with NaAsO2. Aurora-A promoter methylation and gene amplification was not detected in the long-term arsenic treated E7 cells. Furthermore, the expression level of E2F1 transcription factor (E2F1) is increased in the presence of arsenic, and arsenic-related Aurora-A over-expression is transcriptionally regulated by E2F1. We further demonstrated that overexpression of Aurora-A and mutant Ha-ras or Aurora-A and mutant p53 may act additively to trigger arsenic-related bladder and skin cancer

  6. Chronic arsenic poisoning from burning high-arsenic-containing coal in Guizhou, China.

    OpenAIRE

    Liu, Jie; Zheng, Baoshan; Aposhian, H. Vasken; Zhou, Yunshu; Chen, Ming-liang; Zhang, Aihua; Waalkes, Michael P.

    2002-01-01

    Arsenic is an environmental hazard and the reduction of drinking water arsenic levels is under consideration. People are exposed to arsenic not only through drinking water but also through arsenic-contaminated air and food. Here we report the health effects of arsenic exposure from burning high arsenic-containing coal in Guizhou, China. Coal in this region has undergone mineralization and thus produces high concentrations of arsenic. Coal is burned inside the home in open pits for daily cooki...

  7. Transplacental Arsenic Carcinogenesis in Mice

    OpenAIRE

    Waalkes, Michael P.; Liu, Jie; Diwan, Bhalchandra A.

    2007-01-01

    Our work has focused on the carcinogenic effects of in utero arsenic exposure in mice. Our data show a short period of maternal exposure to inorganic arsenic in the drinking water is an effective, multi-tissue carcinogen in the adult offspring. These studies have been reproduced in three temporally separate studies using two different mouse strains. In these studies pregnant mice were treated with drinking water containing sodium arsenite at up to 85 ppm arsenic from day 8 to 18 of gestation,...

  8. Arsenic-induced plant growth of arsenic-hyperaccumulator Pteris vittata: Impact of arsenic and phosphate rock.

    Science.gov (United States)

    Han, Yong-He; Yang, Guang-Mei; Fu, Jing-Wei; Guan, Dong-Xing; Chen, Yanshan; Ma, Lena Q

    2016-04-01

    Phosphate rock (PR) has been shown to promote plant growth and arsenic (As) uptake by As-hyperaccumulator Pteris vittata (PV). However, little is known about its behaviors in agricultural soils. In this study, impact of 50 mg kg(-1) As and/or 1.5% PR amendment on plant As accumulation and growth was investigated by growing PV for 90 d in three agricultural soils. While As amendment significantly increased plant As uptake and substantially promoted PV growth, the opposite was observed with PR amendment. Arsenic amendment increased plant frond As from 16.9-265 to 961-6017 mg kg(-1),whereas PR amendment lowered frond As to 10.2-216 mg kg(-1). The As-induced plant growth stimulation was 69-71%. While PR amendment increased plant Ca and P uptake, As amendment showed opposite results. The PV biomass was highly correlated with plant As at r = 0.82, but with weak correlations with plant Ca or P at r < 0.30. This study confirmed that 1) As significantly promoted PV growth, probably independent of Ca or P uptake, 2) PR amendment didn't enhance plant growth or As uptake by PV in agricultural soils with adequate available P, and 3) PV effluxed arsenite (AsIII) growing in agricultural soils. PMID:26874625

  9. Early Involvement of Death-Associated Protein Kinase Promoter Hypermethylation in the Carcinogenesis of Barrett's Esophageal Adenocarcinoma and Its Association with Clinical Progression

    Directory of Open Access Journals (Sweden)

    Doerthe Kuester

    2007-03-01

    Full Text Available Esophageal Barrett's adenocarcinoma (BA develops through a multistage process, which is associated with the transcriptional silencing of tumor-suppressor genes by promoter CpG island hypermethylation. In this study, we explored the promoter hypermethylation and protein expression of proapoptotic deathassociated protein kinase (DAPK during the multistep Barrett's carcinogenesis cascade. Early BA and paired samples of premalignant lesions of 61 patients were analyzed by methylation-specific polymerase chain reaction and immunohistochemistry. For the association of clinicopathological markers and protein expression, an immunohistochemical tissue microarray analysis of 66 additional BAs of advanced tumor stages was performed. Hypermethylation of DAPK promoter was detected in 20% of normal mucosa, 50% of Barrett's metaplasia, 53% of dysplasia, and 60% of adenocarcinomas, and resulted in a marked decrease in DAPK protein expression (P < .01. The loss of DAPK protein was significantly associated with advanced depth of tumor invasion and advanced tumor stages (P < .001. Moreover, the severity of reflux esophagitis correlated significantly with the hypermethylation rate of the DAPK promoter (P < .003. Thus, we consider DAPK inactivation by promoter hypermethylation as an early event in Barrett's carcinogenesis and suggest that a decreased protein expression of DAPK likely plays a role in the development and progression of BA.

  10. Photooxidation of arsenic(III) to arsenic(V) on the surface of kaolinite clay.

    Science.gov (United States)

    Ding, Wei; Wang, Yajie; Yu, Yingtan; Zhang, Xiangzhi; Li, Jinjun; Wu, Feng

    2015-10-01

    As one of the most toxic heavy metals, the oxidation of inorganic arsenic has drawn great attention among environmental scientists. However, little has been reported on the solar photochemical behavior of arsenic species on top-soil. In the present work, the influencing factors (pH, relative humidity (RH), humic acid (HA), trisodium citrate, and additional iron ions) and the contributions of reactive oxygen species (ROS, mainly HO and HO2/O2(-)) to photooxidation of As(III) to As(V) on kaolinite surfaces under UV irradiation (λ=365nm) were investigated. Results showed that lower pH facilitated photooxidation, and the photooxidation efficiency increased with the increase of RH and trisodium citrate. Promotion or inhibition of As(III) photooxidation by HA was observed at low or high dosages, respectively. Additional iron ions greatly promoted the photooxidation, but excessive amounts of Fe(2+) competed with As(III) for oxidation by ROS. Experiments on scavengers indicated that the HO radical was the predominant oxidant in this system. Experiments on actual soil surfaces proved the occurrence of As(III) photooxidation in real topsoil. This work demonstrates that the photooxidation process of As(III) on the soil surface should be taken into account when studying the fate of arsenic in natural soil newly polluted with acidic wastewater containing As(III). PMID:26456603

  11. 负载铁离子活性炭除砷的研究进展%Research progress on arsenic removal from water using ion-adopted activated carbon

    Institute of Scientific and Technical Information of China (English)

    陆梦楠; 张利波; 李玮; 彭金辉; 夏洪应

    2011-01-01

    Arsenic in natural water is a worldwide problem. Activated carbon adopted ion iron can be used as the adsorbent to efficiently remove arsenic from water,which takes into account the advantages of both flocculation and activated carbon adsorption. The synthesizing method of the materials, main effects on arsenic removed and research development of adsorption model were discussed in details. More specifically, the paper focused on the adsorption capacity of the sample, mainly dependent of pore structure,surface properties and the characteristics of the ion (such as species,distribution,morphology and content). Furthermore,the relation between the arsenic removed and the stirring time, solution pH, temperature and ion strength was studied. The Langmuir model and Freundlich model were used to describe the physical adsorption.The Surface Complex Formation Model was used to illustrate the mechanism of ligand exchange and chemical adsorption. Finally, future developments for arsenic uptake by activated carbon adopted ion iron were reviewed.%砷污染是一个严重的世界问题,在其诸多的去除方法中,负载铁离子活性炭兼顾了活性炭和混凝沉淀的优势,可高效去除砷离子.作者对负载铁离子活性炭的制备方法、影响砷去除率的主要因素和吸附模型的研究现状进行了详细评述,其中负载铁离子活性炭的孔径结构、表面性质,负载铁离子的形貌、分布、种类和质量等决定着其吸附容量;通过调节搅拌时间、溶液pH值、温度和离子强度可提高砷的去除率;Langmuir模型、Freundlich模型可描述砷在负载铁离子活性炭表面的物理吸附,而表面络合模型均可描述其配位体交换、化学吸附机理,最后对其发展方向进行了简要评述.

  12. Arsenic speciation in Mono Lake, California: Response to seasonal stratification and anoxia

    Science.gov (United States)

    Hollibaugh, James T.; Carini, Steve; Gürleyük, Hakan; Jellison, Robert; Joye, Samantha B.; LeCleir, Gary; Meile, Christof; Vasquez, Lydia; Wallschläger, Dirk

    2005-04-01

    Mono Lake is a closed-basin, alkaline, hypersaline lake located at the western edge of the Great Basin in eastern California. We studied the distribution of arsenic (As) species in the water column of Mono Lake between February and November, 2002. This period captured the seasonal progression from winter mixing, through summer thermal stratification, to autumn overturn. Arsenic speciation was determined by ion chromatography-inductively coupled-plasma-mass spectrometry of samples preserved in the field by flash-freezing in liquid nitrogen. We found that arsenic speciation was dominated (>90%) by arsenate when oxygen was detectable. Once levels fell below 6 μmol/L O 2, arsenic speciation shifted to dominance by reduced species. Arsenate and arsenite co-occurred in a transition zone immediately below the base of the oxycline and low but significant concentrations of arsenate were occasionally detected in sulfidic hypolimnion samples. Thio-arsenic species were the dominant form of As found in sulfidic waters. Maxima of thio-arsenic species with stoichiometries consistent with mono-, di- and trithio-arsenic occurred in succession as sulfide concentration increased. A compound with a stoichiometry consistent with trithio-arsenic was the dominant As species (˜50% of total As) in high sulfide (2 mmol/L) bottom water. Lower concentrations of total As in bottom water relative to surface water suggest precipitation of As/S mineral phases in response to sulfide accumulation during prolonged anoxia.

  13. Arsenic speciation in edible mushrooms.

    Science.gov (United States)

    Nearing, Michelle M; Koch, Iris; Reimer, Kenneth J

    2014-12-16

    The fruiting bodies, or mushrooms, of terrestrial fungi have been found to contain a high proportion of the nontoxic arsenic compound arsenobetaine (AB), but data gaps include a limited phylogenetic diversity of the fungi for which arsenic speciation is available, a focus on mushrooms with higher total arsenic concentrations, and the unknown formation and role of AB in mushrooms. To address these, the mushrooms of 46 different fungus species (73 samples) over a diverse range of phylogenetic groups were collected from Canadian grocery stores and background and arsenic-contaminated areas. Total arsenic was determined using ICP-MS, and arsenic speciation was determined using HPLC-ICP-MS and complementary X-ray absorption spectroscopy (XAS). The major arsenic compounds in mushrooms were found to be similar among phylogenetic groups, and AB was found to be the major compound in the Lycoperdaceae and Agaricaceae families but generally absent in log-growing mushrooms, suggesting the microbial community may influence arsenic speciation in mushrooms. The high proportion of AB in mushrooms with puffball or gilled morphologies may suggest that AB acts as an osmolyte in certain mushrooms to help maintain fruiting body structure. The presence of an As(III)-sulfur compound, for the first time in mushrooms, was identified in the XAS analysis. Except for Agaricus sp. (with predominantly AB), inorganic arsenic predominated in most of the store-bought mushrooms (albeit with low total arsenic concentrations). Should inorganic arsenic predominate in these mushrooms from contaminated areas, the risk to consumers under these circumstances should be considered. PMID:25417842

  14. Multiple endocrine neoplasia (MEN) - like syndrome and other hormonal factors of promotion and progression of thyroid gland cancer in males-liquidators of Chernobyl accident consequences

    International Nuclear Information System (INIS)

    The clinical and laboratory endocrinological screening performed in 1,000 males - liquidators of Chernobyl accident consequences revealed hormonal factors leading to node formation and having unfavourable influence on progression and promotion of thyroid gland cancer. The factors include syndrome of low thriiodothyronine, hyperprolactinemia, latent hypothyrosis and increased production of thyroglobulin. Peculiarities of hormonal status in liquidators allow us to suggest the presence of MEN-like syndrome among the liquidators population. Possible mechanisms of expression of RET oncogene in adults that may result in MEN- like syndrome have been discussed. (author)

  15. Arsenic Is A Genotoxic Carcinogen

    Science.gov (United States)

    Arsenic is a recognized human carcinogen; however, there is controversy over whether or not it should be considered a genotoxic carcinogen. Many possible modes of action have been proposed on how arsenic induces cancer, including inhibiting DNA repair, altering methylation patter...

  16. Chromatin inactivation precedes de novo dna methylation during the progressive epigenetic silencing of the rassf1a promoter

    Energy Technology Data Exchange (ETDEWEB)

    Strunnikova Maria; Schagdarsurengin, Undraga; Kehlen, Astrid; Garbe, James C.; Stampfer, Martha R.; Dammann, Reinhard

    2005-02-23

    Epigenetic inactivation of the RASSF1A tumor suppressor by CpG island methylation was frequently detected in cancer. However, the mechanisms of this aberrant DNA methylation are unknown. In the RASSF1A promoter, we characterized four Sp1 sites, which are frequently methylated in cancer. We examined the functional relationship between DNA methylation, histone modification, Sp1 binding, and RASSF1A expression in proliferating human mammary epithelial cells. With increasing passages, the transcription of RASSF1A was dramatically silenced. This inactivation was associated with deacetylation and lysine 9 trimethylation of histone H3 and an impaired binding of Sp1 at the RASSF1A promoter. In mammary epithelial cells that had overcome a stress-associated senescence barrier, a spreading of DNA methylation in the CpG island promoter was observed. When the RASSF1A-silenced cells were treated with inhibitors of DNA methyltransferase and histone deacetylase, binding of Sp1 and expression of RASSF1 A reoccurred. In summary, we observed that histone H3 deacetylation and H3 lysine 9 trimethylation occur in the same time window as gene inactivation and precede DNA methylation. Our data suggest that in epithelial cells, histone inactivation may trigger de novo DNA methylation of the RASSF1A promoter and this system may serve as a model for CpG island inactivation of tumor suppressor genes.

  17. Assessing tumor progression factors by somatic gene transfer into a mouse model: Bcl-xL promotes islet tumor cell invasion.

    Directory of Open Access Journals (Sweden)

    Yi-Chieh Nancy Du

    2007-10-01

    Full Text Available Tumors develop through multiple stages, implicating multiple effectors, but the tools to assess how candidate genes contribute to stepwise tumor progression have been limited. We have developed a novel system in which progression of phenotypes in a mouse model of pancreatic islet cell tumorigenesis can be used to measure the effects of genes introduced by cell-type-specific infection with retroviral vectors. In this system, bitransgenic mice, in which the rat insulin promoter (RIP drives expression of both the SV40 T antigen (RIP-Tag and the receptor for subgroup A avian leukosis virus (RIP-tva, are infected with avian viral vectors carrying cDNAs encoding candidate progression factors. Like RIP-Tag mice, RIP-Tag; RIP-tva bitransgenic mice develop isolated carcinomas by approximately 14 wk of age, after progression through well-defined stages that are similar to aspects of human tumor progression, including hyperplasia, angiogenesis, adenoma, and invasive carcinoma. When avian retroviral vectors carrying a green fluorescent protein marker were introduced into RIP-Tag; RIP-tva mice by intra-cardiac injection at the hyperplastic or early dysplastic stage of tumorigenesis, approximately 20% of the TVA-positive cells were infected and expressed green fluorescent proteins as measured by flow cytometry. Similar infection with vectors carrying cDNA encoding either of two progression factors, a dominant-negative version of cadherin 1 (dnE-cad or Bcl-xL, accelerated the formation of islet tumors with invasive properties and pancreatic lymph node metastasis. To begin studying the mechanism by which Bcl-xL, an anti-apoptotic protein, promotes invasion and metastasis, RIP-Tag; RIP-tva pancreatic islet tumor cells were infected in vitro with RCASBP-Bcl-xL. Although no changes were observed in rates of proliferation or apoptosis, Bcl-xL altered cell morphology, remodeled the actin cytoskeleton, and down-regulated cadherin 1; it also induced cell migration and

  18. Elevated Human telomerase reverse transcriptase gene expression in blood cells associated with chronic and arsenic exposure in Inner Mongolia, China

    Science.gov (United States)

    BACKGROUND: Arsenic exposure is associated with human cancer. Telomerase containing the catalytic subunit, human telomerase reverse transcriptase (hTERT), can extend telomeres of chromosomes, delay senescence and promoting cell proliferation leading to tumorigenesis. OBJECTIVE:...

  19. Arsenic concentrations in Chinese coals

    International Nuclear Information System (INIS)

    The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the concentration of Arsenic is 6.4 ± 0.5 mg/kg and the geometric mean is 4.0 ± 8.5 mg/kg. The level of arsenic in China is higher in northeastern and southern provinces, but lower in northwestern provinces. The relationship between arsenic content and coal-forming period, coal rank is studied. It was observed that the arsenic contents decreases with coal rank in the order: Tertiary > Early Jurassic > Late Triassic > Late Jurassic > Middle Jurassic > Late Permian > Early Carboniferous > Middle Carboniferous > Late Carboniferous > Early Permian; It was also noted that the arsenic contents decrease in the order: Subbituminous > Anthracite > Bituminous. However, compared with the geological characteristics of coal forming region, coal rank and coal-forming period have little effect on the concentration of arsenic in Chinese coal. The average arsenic concentration of Chinese coal is lower than that of the whole world. The health problems in China derived from in coal (arsenism) are due largely to poor local life-style practices in cooking and home heating with coal rather than to high arsenic contents in the coal

  20. Technologies for Arsenic Removal from Water: Current Status and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Nina Ricci Nicomel

    2015-12-01

    Full Text Available This review paper presents an overview of the available technologies used nowadays for the removal of arsenic species from water. Conventionally applied techniques to remove arsenic species include oxidation, coagulation-flocculation, and membrane techniques. Besides, progress has recently been made on the utility of various nanoparticles for the remediation of contaminated water. A critical analysis of the most widely investigated nanoparticles is presented and promising future research on novel porous materials, such as metal organic frameworks, is suggested.

  1. Expression of Heterogenous Arsenic Resistance Genes in the Obligately Autotrophic Biomining Bacterium Thiobacillus ferrooxidans.

    Science.gov (United States)

    Peng, J B; Yan, W M; Bao, X Z

    1994-07-01

    Two arsenic-resistant plasmids were constructed and introduced into Thiobacillus ferrooxidans strains by conjugation. The plasmids with the replicon of wide-host-range plasmid RSF1010 were stable in T. ferrooxidans. The arsenic resistance genes originating from the heterotroph were expressed in this obligately autotrophic bacterium, but the promoter derived from T. ferrooxidans showed no special function in its original host. PMID:16349341

  2. Arsenic volatilization in model anaerobic biogas digesters

    International Nuclear Information System (INIS)

    Highlights: • Arsenic is volatilized form all model anaerobic digesters, including the non-treated ones. • Volatile As species can be identified and quantified in all digesters. • Non-arsenic treated digesters volatilization rates are higher than Roxarsone treated ones. - Abstract: Arsenic is a class 1 non-threshold carcinogen which is highly ubiquitous. Arsenic undergoes many different transformations (biotic or abiotic) between and within environmental compartments, leading to a number of different chemical species possessing different properties and toxicities. One specific transformation is As biotic volatilization which is coupled with As biomethylation and has been scarcely studied due to inherent sampling issues. Arsenic methylation/volatilization is also linked with methanogenesis and occurs in anaerobic environments. In China, rice straw and animal manure are very often used to produce biogas and both can contain high amounts of As, especially if the rice is grown in areas with heavy mining or smelting industries and if Roxarsone is fed to the animals. Roxarsone is an As-containing drug which is widely used in China to control coccidian intestinal parasites, to improve feed efficiency and to promote rapid growth. Previous work has shown that this compound degrades to inorganic As under anaerobic conditions. In this study the focus is on biotic transformations of As in small microcosms designed as biogas digester models (BDMs) using recently validated As traps, thus, enabling direct quantification and identification of volatile As species. It is shown that although there was a loss of soluble As in the BDMs, their conditions favored biomethylation. All reactors produced volatile As, especially the monomethylarsonic acid spiked ones with 413 ± 148 ng As (mean ± SD, n = 3) which suggest that the first methylation step, from inorganic As, is a limiting factor. The most abundant species was trimethylarsine, but the toxic arsine was present in the

  3. Urinary Arsenic Metabolites of Subjects Exposed to Elevated Arsenic Present in Coal in Shaanxi Province, China

    OpenAIRE

    Linsheng Yang; Jianwei Gao; Jiangping Yu

    2011-01-01

    In contrast to arsenic (As) poisoning caused by naturally occurring inorganic arsenic-contaminated water consumption, coal arsenic poisoning (CAP) induced by elevated arsenic exposure from coal combustion has rarely been reported. In this study, the concentrations and distributions of urinary arsenic metabolites in 57 volunteers (36 subjects with skin lesions and 21 subjects without skin lesions), who had been exposed to elevated levels of arsenic present in coal in Changshapu village in the ...

  4. Olfactomedin 4 deficiency promotes prostate neoplastic progression and is associated with upregulation of the hedgehog-signaling pathway

    OpenAIRE

    Hongzhen Li; Wenli Liu; Weiping Chen; Jianqiong Zhu; Chu-Xia Deng; Rodgers, Griffin P.

    2015-01-01

    Loss of olfactomedin 4 (OLFM4) gene expression is associated with the progression of human prostate cancer, but its role and the molecular mechanisms involved in this process have not been completely understood. In this study, we found that Olfm4-knockout mice developed prostatic intraepithelial neoplasia and prostatic adenocarcinoma. Importantly, we found that the hedgehog-signaling pathway was significantly upregulated in the Olfm4-knockout mouse model. We also found that restoration of OLF...

  5. The pro-inflammatory peptide LL-37 promotes ovarian tumor progression through recruitment of multipotent mesenchymal stromal cells

    OpenAIRE

    Coffelt, Seth B.; Marini, Frank C.; Watson, Keri; Zwezdaryk, Kevin J.; Dembinski, Jennifer L.; LaMarca, Heather L; Tomchuck, Suzanne L.; zu Bentrup, Kerstin Honer; Danka, Elizabeth S; Henkle, Sarah L.; Scandurro, Aline B.

    2009-01-01

    Bone marrow-derived mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs) have been shown to engraft into the stroma of several tumor types, where they contribute to tumor progression and metastasis. However, the chemotactic signals mediating MSC migration to tumors remain poorly understood. Previous studies have shown that LL-37 (leucine, leucine-37), the C-terminal peptide of human cationic antimicrobial protein 18, stimulates the migration of various cell types and is over...

  6. Arsenic retention and transport behavior in the presence of typical anionic and nonionic surfactants.

    Science.gov (United States)

    Liang, Chuan; Wang, Xianliang; Peng, Xianjia

    2016-01-01

    The massive production and wide use of surfactants have resulted in a large amount of surfactant residuals being discharged into the environment, which could have an impact on arsenic behavior. In the present study, the influence of the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and nonionic surfactant polyethylene glycol octylphenyl ether (Triton X-100) on arsenic behavior was investigated in batch and column tests. The presence of SDBS and Triton X-100 reduced arsenic retention onto ferrihydrite (FH), enhanced arsenic transport through FH coated sand (FH-sand) columns and promoted arsenic release from the FH surface. With coexisting surfactants in solution, the equilibrium adsorbed amount of arsenic on FH decreased by up to 29.7% and the adsorption rate decreased by up to 52.3%. Pre-coating with surfactants caused a decrease in the adsorbed amount and adsorption rate of arsenic by up to 15.1% and 58.3%, respectively. Because of the adsorption attenuation caused by surfactants, breakthrough of As(V) and As(III) with SDBS in columns packed with FH-sand was 23.8% and 14.3% faster than that in those without SDBS, respectively. In columns packed with SDBS-coated FH-sand, transport of arsenic was enhanced to a greater extent. Breakthrough of As(V) and As(III) was 52.4% and 43.8% faster and the cumulative retention amount was 44.5% and 57.3% less than that in pure FH-sand column systems, respectively. Mobilization of arsenic by surfactants increased with the increase of the initial adsorbed amount of arsenic. The cumulative release amount of As(V) and As(III) from the packed column reached 10.8% and 36.0%, respectively. PMID:26899663

  7. Effect of organic matter amendment, arsenic amendment and water management regime on rice grain arsenic species

    International Nuclear Information System (INIS)

    Arsenic accumulation in rice grain has been identified as a major problem in some regions of Asia. A study was conducted to investigate the effect of increased organic matter in the soil on the release of arsenic into soil pore water and accumulation of arsenic species within rice grain. It was observed that high concentrations of soil arsenic and organic matter caused a reduction in plant growth and delayed flowering time. Total grain arsenic accumulation was higher in the plants grown in high soil arsenic in combination with high organic matter, with an increase in the percentage of organic arsenic species observed. The results indicate that the application of organic matter should be done with caution in paddy soils which have high soil arsenic, as this may lead to an increase in accumulation of arsenic within rice grains. Results also confirm that flooding conditions substantially increase grain arsenic. -- Highlights: ► High soil arsenic and organic matter caused a reduction in plant growth. ► A delayed flowering time was observed in high arsenic and organic matter soil. ► Total grain arsenic increased in high arsenic and organic matter soil. ► Percentage organic arsenic in the grain altered in arsenic and organic matter soil. -- The addition of high amounts of organic matter to soils led to an increase in total rice grain arsenic, as well as alteration in the percentage arsenic species in the rice grains

  8. The potential biological mechanisms of arsenic-induced diabetes mellitus

    International Nuclear Information System (INIS)

    arsenic exposure, oxidative stress is increased and the expression of tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) is upregulated. Both of these two cytokines have been well known for their effect on the induction of insulin resistance. Arsenite at physiologically relevant concentration also shows inhibitory effect on the expression of peroxisome proliferator-activated receptor γ (PPARγ), a nuclear hormone receptor important for activating insulin action. Oxidative stress has been suggested as a major pathogenic link to both insulin resistance and β cell dysfunction through mechanisms involving activation of nuclear factor-κB (NF-κB), which is also activated by low levels of arsenic. Although without supportive data, superoxide production induced by arsenic exposure can theoretically impair insulin secretion by interaction with uncoupling protein 2 (UCP2), and oxidative stress can also cause amyloid formation in the pancreas, which could progressively destroy the insulin-secreting β cells. Individual susceptibility with respect to genetics, nutritional status, health status, detoxification capability, interactions with other trace elements, and the existence of other well-recognized risk factors of diabetes mellitus can influence the toxicity of arsenic on organs involved in glucose metabolism and determine the progression of insulin resistance and impaired insulin secretion to a status of persistent hyperglycemia or diabetes mellitus. In conclusions, insulin resistance and β cell dysfunction can be induced by chronic arsenic exposure. These defects may be responsible for arsenic-induced diabetes mellitus, but investigations are required to test this hypothesis

  9. The role of active arsenic species produced by metabolic reduction of dimethylarsinic acid in genotoxicity and tumorigenesis

    International Nuclear Information System (INIS)

    In recent research of arsenic carcinogenesis, many researchers have directed their attention to methylated metabolites of inorganic arsenics. Because of its high cytotoxicity and genotoxicity, trivalent dimethylated arsenic, which can be produced by the metabolic reduction of dimethylarsinic acid (DMA), has attracted considerable attention from the standpoint of arsenic carcinogenesis. In the present paper, we examined trivalent dimethylated arsenic and its further metabolites for their chemical properties and biological behavior such as genotoxicity and tumorigenicity. Our in vitro and in vivo experiments suggested that the formation of cis-thymine glycol in DNA was induced via the production of dimethylated arsenic peroxide by the reaction of trivalent dimethylated arsenic with molecular oxygen, but not via the production of common reactive oxygen species (ROS; superoxide, hydrogen peroxide, hydroxyl radical, etc.). Thus, dimethylated arsenic peroxide may be the main species responsible for the tumor promotion in skin tumorigenesis induced by exposure to DMA. Free radical species, such as dimethylarsenic radical [(CH3)2As·] and dimethylarsenic peroxy radical [(CH3)2AsOO·], that are produced by the reaction of molecular oxygen and dimethylarsine [(CH3)2AsH], which is probably a further reductive metabolite of trivalent dimethylated arsenic, may be main agents for initiation in mouse lung tumorigenesis

  10. 非洲推动传统医学发展的举措与进展%African initiatives and progress in promoting the development of traditional medicine

    Institute of Scientific and Technical Information of China (English)

    黄睿; 潘艳丽; 柳长华

    2014-01-01

    To study the initiatives and progress of African nations in promoting the development of traditional medicine to determine if these measures can be applied to the protection of traditional Chinese medicine knowledge. Information research methods were used to collect and analyze relevant literature. The development of African traditional medicine has been effectively promoted through various measures taken by African organizations and governments. In recent years, Africa has achieved remarkable results in promoting the development of traditional medicine. Many other countries will benefit from studying their examples and adopting similar measures.%本文采用信息研究的方法收集和分析相关文献,重点研究了非洲推动传统医学发展的举措与进展,为中医药传统知识保护提供思路。结果表明,非洲各组织和各国家政府采取多种措施,有力地促进了非洲传统医学发展,其成效值得其他国家推广和借鉴。

  11. Akt/Protein Kinase B-Dependent Phosphorylation and Inactivation of WEE1Hu Promote Cell Cycle Progression at G2/M Transition

    Science.gov (United States)

    Katayama, Kazuhiro; Fujita, Naoya; Tsuruo, Takashi

    2005-01-01

    The serine/threonine kinase Akt is known to promote cell growth by regulating the cell cycle in G1 phase through activation of cyclin/Cdk kinases and inactivation of Cdk inhibitors. However, how the G2/M phase is regulated by Akt remains unclear. Here, we show that Akt counteracts the function of WEE1Hu. Inactivation of Akt by chemotherapeutic drugs or the phosphatidylinositide-3-OH kinase inhibitor LY294002 induced G2/M arrest together with the inhibitory phosphorylation of Cdc2. Because the increased Cdc2 phosphorylation was completely suppressed by wee1hu gene silencing, WEE1Hu was associated with G2/M arrest induced by Akt inactivation. Further analyses revealed that Akt directly bound to and phosphorylated WEE1Hu during the S to G2 phase. Serine-642 was identified as an Akt-dependent phosphorylation site. WEE1Hu kinase activity was not affected by serine-642 phosphorylation. We revealed that serine-642 phosphorylation promoted cytoplasmic localization of WEE1Hu. The nuclear-to-cytoplasmic translocation was mediated by phosphorylation-dependent WEE1Hu binding to 14-3-3θ but not 14-3-3β or -σ. These results indicate that Akt promotes G2/M cell cycle progression by inducing phosphorylation-dependent 14-3-3θ binding and cytoplasmic localization of WEE1Hu. PMID:15964826

  12. 香蕉根际促生菌的研究展望%Progress and Prospect on Plant Growth - promoting Rhizobacteria of Banana Rhizosphere

    Institute of Scientific and Technical Information of China (English)

    李文英; 彭智平; 于俊红; 黄继川; 宋慧敏

    2011-01-01

    植物根际促生菌(plant growth-promoting rhizobacteria,PGPR)是一类具有促进作物生长并增加产量的作用,兼有抑制植物病原菌、根际有害微生物的根际微生物,作为生物肥料和生物农药的重要资源库,PGPR相关研究受到越来越多的重视.着重从PGPR的概念演变、功能机制、研究手段及应用现状等方面进行综述,并在分析香蕉根际促生菌研究现状的基础上,对香蕉PGPR研究的理论意义和现实意义提出讨论与展望.%Plant growth-promoting rhizobacteria (PGPR) are microorganisms colonized in the plant rhizosphere, which can promote the plant growth and yield, and inhibit plant pathogens.As an important resource of biofertilizer and biocontrol agents, PGPR have been paid more and more attention by researchers in the sustainable agriculture.This paper reviewed progresses on the concept development, functioning mechanisms, study techniques and the application of PGPR.In addition, the theoretical and practical significance of banana PG PR were disscused, and some future directions in PGPR study were suggested.

  13. MicroRNA-124 slows down the progression of Huntington′s disease by promoting neurogenesis in the striatum

    Directory of Open Access Journals (Sweden)

    Tian Liu

    2015-01-01

    Full Text Available MicroRNA-124 contributes to neurogenesis through regulating its targets, but its expression both in the brain of Huntington′s disease mouse models and patients is decreased. However, the effects of microRNA-124 on the progression of Huntington′s disease have not been reported. Results from this study showed that microRNA-124 increased the latency to fall for each R6/2 Huntington′s disease transgenic mouse in the rotarod test. 5-Bromo-2′-deoxyuridine (BrdU staining of the striatum shows an increase in neurogenesis. In addition, brain-derived neurotrophic factor and peroxisome proliferator-activated receptor gamma coactivator 1-alpha protein levels in the striatum were increased and SRY-related HMG box transcription factor 9 protein level was decreased. These findings suggest that microRNA-124 slows down the progression of Huntington′s disease possibly through its important role in neuronal differentiation and survival.

  14. Olfactomedin 4 deficiency promotes prostate neoplastic progression and is associated with upregulation of the hedgehog-signaling pathway.

    Science.gov (United States)

    Li, Hongzhen; Liu, Wenli; Chen, Weiping; Zhu, Jianqiong; Deng, Chu-Xia; Rodgers, Griffin P

    2015-01-01

    Loss of olfactomedin 4 (OLFM4) gene expression is associated with the progression of human prostate cancer, but its role and the molecular mechanisms involved in this process have not been completely understood. In this study, we found that Olfm4-knockout mice developed prostatic intraepithelial neoplasia and prostatic adenocarcinoma. Importantly, we found that the hedgehog-signaling pathway was significantly upregulated in the Olfm4-knockout mouse model. We also found that restoration of OLFM4 in human prostate-cancer cells that lack OLFM4 expression significantly downregulated hedgehog signaling-pathway component expression. Furthermore, we demonstrated that the OLFM4 protein interacts with sonic hedgehog protein, as well as significantly inhibits GLI-reporter activity. Bioinformatic and immunohistochemistry analyses revealed that decreased OLFM4 and increased SHH expression was significantly associated with advanced human prostate cancer. Thus, olfactomedin 4 appears to play a critical role in regulating progression of prostate cancer, and has potential as a new biomarker for prostate cancer. PMID:26581960

  15. β2-adrenergic receptor signaling promotes pancreatic ductal adenocarcinoma (PDAC) progression through facilitating PCBP2-dependent c-myc expression.

    Science.gov (United States)

    Wan, Chunhua; Gong, Chen; Zhang, Haifeng; Hua, Lu; Li, Xiaohong; Chen, Xudong; Chen, Yinji; Ding, Xiaoling; He, Song; Cao, Wei; Wang, Yingying; Fan, Shaoqing; Xiao, Ying; Zhou, Guoxiong; Shen, Aiguo

    2016-04-01

    The β2-adrenergic receptor (β2-AR) plays a crucial role in pancreatic ductal adenocarcinoma (PDAC) progression. In this report, we identified poly(rC)-binding protein 2 (PCBP2) as a novel binding partner for β2-AR using immunoprecipitation-mass spectrometry (IP-MS) approach. The association between β2-AR and PCBP2 was verified using reciprocal immunoprecipitation. Importantly, we found significant interaction and co-localization of the two proteins in the presence of β2-AR agonist in Panc-1 and Bxpc3 PDAC cells. β2-AR-induced recruitment of PCBP2 led to augmented protein level of c-myc in PDAC cells, likely as a result of enhanced internal ribosome entry segment (IRES)-mediated translation of c-myc. The activation of β2-AR accelerated cell proliferation and colony formation, while knockdown of PCBP2 or c-myc restrained the effect. Furthermore, overexpression of PCBP2 was observed in human PDAC cell lines and tissue specimens compared to the normal pancreatic ductal epithelial cells and the non-cancerous tissues respectively. Overexpression of β2-AR and PCBP2 was associated with advanced tumor stage and significantly worsened prognosis in patients with PDAC. Our results elucidate a new molecular mechanism by which β2-AR signaling facilitates PDAC progression through triggering PCBP2-dependent c-myc expression. PMID:26803058

  16. Overexpressed KDM5B is associated with the progression of glioma and promotes glioma cell growth via downregulating p21

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Bin [Department of Neurosurgery, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038 (China); Hu, Zhiqiang, E-mail: zhiqhutg@126.com [Department of Neurosurgery, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038 (China); Huang, Hui; Zhu, Guangtong; Xiao, Zhiyong [Department of Neurosurgery, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038 (China); Wan, Weiqing; Zhang, Peng; Jia, Wang; Zhang, Liwei [Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050 (China)

    2014-11-07

    Highlights: • KDM5B is overexpressed in glioma samples. • KDM5B stimulated proliferation of glioma cells. • Inhibition of p21contributes to KDM5B-induced proliferation. - Abstract: Epigenetic alterations such as aberrant expression of histone-modifying enzymes have been implicated in tumorigenesis. Upregulation of lysine (K)-specific demethylase 5B (KDM5B) has been reported in a variety of malignant tumors. However, the impact of KDM5B in glioma remains unclear. The objective of this study was to investigate the expression and prognostic value of KDM5B in glioma. In clinical glioma samples, we found that KDM5B expression was significantly upregulated in cancer lesions compared with normal brain tissues. Kaplan–Meier analysis showed that patients with glioma and higher KDM5B expression tend to have shorter overall survival time. By silencing or overexpressing KDM5B in glioma cells, we found that KDM5B could promote cell growth both in vitro and in vivo. Moreover, we demonstrated that KDM5B promoted glioma proliferation partly via regulation of the expression of p21. Our study provided evidence that KDM5B functions as a novel tumor oncogene in glioma and may be a potential therapeutic target for glioma management.

  17. Overexpressed KDM5B is associated with the progression of glioma and promotes glioma cell growth via downregulating p21

    International Nuclear Information System (INIS)

    Highlights: • KDM5B is overexpressed in glioma samples. • KDM5B stimulated proliferation of glioma cells. • Inhibition of p21contributes to KDM5B-induced proliferation. - Abstract: Epigenetic alterations such as aberrant expression of histone-modifying enzymes have been implicated in tumorigenesis. Upregulation of lysine (K)-specific demethylase 5B (KDM5B) has been reported in a variety of malignant tumors. However, the impact of KDM5B in glioma remains unclear. The objective of this study was to investigate the expression and prognostic value of KDM5B in glioma. In clinical glioma samples, we found that KDM5B expression was significantly upregulated in cancer lesions compared with normal brain tissues. Kaplan–Meier analysis showed that patients with glioma and higher KDM5B expression tend to have shorter overall survival time. By silencing or overexpressing KDM5B in glioma cells, we found that KDM5B could promote cell growth both in vitro and in vivo. Moreover, we demonstrated that KDM5B promoted glioma proliferation partly via regulation of the expression of p21. Our study provided evidence that KDM5B functions as a novel tumor oncogene in glioma and may be a potential therapeutic target for glioma management

  18. Association of oxidative stress with arsenic methylation in chronic arsenic-exposed children and adults

    International Nuclear Information System (INIS)

    Though oxidative stress is recognized as an important pathogenic mechanism of arsenic, and arsenic methylation capacity is suggested to be highly involved in arsenic-related diseases, the association of arsenic methylation capacity with arsenic-induced oxidative stress remains unclear. To explore oxidative stress and its association with arsenic methylation, cross-sectional studies were conducted among 208 high and 59 low arsenic-exposed subjects. Levels of urinary arsenic species [inorganic arsenic (iAs), monomethylated arsenic (MMA) and dimethylated arsenic (DMA)] were determined by hydride generation atomic absorption spectrometry. Proportions of urinary arsenic species, the first methylation ratio (FMR) and the secondary methylation ratio (SMR) were used as indicators for arsenic methylation capacity. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations were analyzed by enzyme-linked immunosorbent assay kits. Reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity in whole blood were determined to reflect anti-oxidative status. The high arsenic-exposed children and adults were significantly increased in urinary 8-OHdG concentrations but decreased in blood GSH levels compared with the low exposed children and adults. In multiple linear regression models, blood GSH levels and urinary 8-OHdG concentrations of arsenic-exposed children and adults showed strong associations with the levels of urinary arsenic species. Arsenic-exposed subjects in the lower and the upper quartiles of proportions of urinary arsenic species, FMR or SMR were significantly different in urinary 8-OHdG, blood GSH and SOD. The associations of arsenic methylation capacity with 8-OHdG, GSH and SOD were also observed in multivariate regression analyses. These results may provide linkage between arsenic methylation capacity and oxidative stress in humans and suggest that adverse health effects induced by arsenic are related to arsenic methylation through oxidative stress

  19. Arsenic-induced alterations in the contact hypersensitivity response in Balb/c mice

    International Nuclear Information System (INIS)

    Previous studies in our laboratory indicate that arsenic alters secretion of growth promoting and inflammatory cytokines in the skin that can regulate the migration and maturation of Langerhans cells (LC) during allergic contact dermatitis. Therefore, we hypothesized that arsenic may modulate hypersensitivity responses to cutaneous sensitizing agents by altering cytokine production, LC migration, and T-cell proliferation. To investigate this hypothesis, we examined the induction and elicitation phases of dermal sensitization. Mice exposed to 50 mg/l arsenic in the drinking water for 4 weeks demonstrated a reduction in lymph node cell (LNC) proliferation and ear swelling following sensitization with 2,4-dinitrofluorobenzene (DNFB), compared to control mice. LC and T-cell populations in the draining lymph nodes of DNFB-sensitized mice were evaluated by fluorescence-activated cell sorting; activated LC were reduced in cervical lymph nodes, suggesting that LC migration may be altered following arsenic exposure. Lymphocytes from arsenic-treated animals sensitized with fluorescein isothiocyanate (FITC) exhibited reduced proliferative responses following T-cell mitogen stimulation in vitro; however, lymphocyte proliferation from nonsensitized, arsenic-treated mice was comparable to controls. Arsenic exposure also reduced the number of thioglycollate-induced peritoneal macrophages and circulating neutrophils. These studies demonstrate that repeated, prolonged exposure to nontoxic concentrations of sodium arsenite alters immune cell populations and results in functional changes in immune responses, specifically attenuation of contact hypersensitivity

  20. Long non-coding RNA APTR promotes the activation of hepatic stellate cells and the progression of liver fibrosis

    International Nuclear Information System (INIS)

    In this study, we aimed at assessing a role of Alu-mediated p21 transcriptional regulator (APTR) in hepatofibrogenesis. APTR was upregulated in fibrotic liver samples and activated hepatic stellate cells (HSCs). Knockdown of APTR inhibited the activation of HSCs in vitro and mitigated the accumulation of collagen in vivo. Importantly, APTR silencing could abrogate TGF-β1-induced upregulation of α-SMA in HSCs. In addition, inhibition of cell cycle and cell proliferation by APTR knockdown was attenuated by p21 siRNA1 in primary HSCs. Finally, serum APTR levels were increased in patients with liver cirrhosis, indicating a potential biomarker for liver cirrhosis. Collectively, evidence is proposed for a new biological role of APTR in hepatofibrogenesis. - Highlights: • APTR is upregulated in fibrotic liver tissues and activated HSCs. • APTR silencing inhibits HSC activation and the progression of liver fibrosis. • Antifibrotic effect of APTR silencing is achieved by increasing p21

  1. NOK/STYK1 promotes the genesis and remodeling of blood and lymphatic vessels during tumor progression.

    Science.gov (United States)

    Liu, Yue; Li, Tianqi; Hu, Dan; Zhang, Shuping

    2016-09-01

    Previous studies have indicated that the overexpression of NOK, also named STYK1, led to tumorigenesis and metastasis. Here, we provide evidence that increased expression of NOK/STYK1 caused marked alterations in the overall and inner structures of tumors and substantially facilitates the genesis and remodeling of the blood and lymphatic vessels during tumor progression. In particular, NOK-expressed HeLa stable cells (HeLa-K) significantly enhanced tumor growth and metastasis in xenografted nude mice. Hematoxylin and eosin (HE) staining demonstrated that the tumor tissues generated by HeLa-K cells were much more ichorous and had more interspaces than those generated by control HeLa cells (HeLa-C). The fluorescent areas stained with cluster of differentiation 31 (CD31), a marker protein for blood vessels, appeared to be in different patterns. The total blood vessels, especially the ring patterns, within the tumors of the HeLa-K group were highly enriched compared with those in the HeLa-C group. NOK-HA was demonstrated to be well colocalized with CD31 in the wall of the tubular structures within tumor tissues. Interestingly, antibody staining of the lymphatic vessel endothelial hyaluronan receptor (LYVE-1) further revealed the increase in ring (oratretic strip-like) lymphatic vessels in either the peritumoral or intratumoral areas in the HeLa-K group compared with the HeLa-C group. Consistently, the analysis of human cancerous tissue also showed that NOK was highly expressed in the walls of tubular structures. Thus, our results reveal a novel tumorigenic function of NOK to mediate the genesis and remodeling of blood and lymphatic vessels during tumor progression. PMID:27444381

  2. The pro-inflammatory peptide LL-37 promotes ovarian tumor progression through recruitment of multipotent mesenchymal stromal cells.

    Science.gov (United States)

    Coffelt, Seth B; Marini, Frank C; Watson, Keri; Zwezdaryk, Kevin J; Dembinski, Jennifer L; LaMarca, Heather L; Tomchuck, Suzanne L; Honer zu Bentrup, Kerstin; Danka, Elizabeth S; Henkle, Sarah L; Scandurro, Aline B

    2009-03-10

    Bone marrow-derived mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs) have been shown to engraft into the stroma of several tumor types, where they contribute to tumor progression and metastasis. However, the chemotactic signals mediating MSC migration to tumors remain poorly understood. Previous studies have shown that LL-37 (leucine, leucine-37), the C-terminal peptide of human cationic antimicrobial protein 18, stimulates the migration of various cell types and is overexpressed in ovarian, breast, and lung cancers. Although there is evidence to support a pro-tumorigenic role for LL-37, the function of the peptide in tumors remains unclear. Here, we demonstrate that neutralization of LL-37 in vivo significantly reduces the engraftment of MSCs into ovarian tumor xenografts, resulting in inhibition of tumor growth as well as disruption of the fibrovascular network. Migration and invasion experiments conducted in vitro indicated that the LL-37-mediated migration of MSCs to tumors likely occurs through formyl peptide receptor like-1. To assess the response of MSCs to the LL-37-rich tumor microenvironment, conditioned medium from LL-37-treated MSCs was assessed and found to contain increased levels of several cytokines and pro-angiogenic factors compared with controls, including IL-1 receptor antagonist, IL-6, IL-10, CCL5, VEGF, and matrix metalloproteinase-2. Similarly, Matrigel mixed with LL-37, MSCs, or the combination of the two resulted in a significant number of vascular channels in nude mice. These data indicate that LL-37 facilitates ovarian tumor progression through recruitment of progenitor cell populations to serve as pro-angiogenic factor-expressing tumor stromal cells. PMID:19234121

  3. Discovery of the Arsenic Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  4. Arsenic exposure disrupts epigenetic regulation of SIRT1 in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, Katharine J. [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia); Holloway, Adele [Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS 7000 (Australia); Cook, Anthony L. [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia); Chin, Suyin P. [Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS 7000 (Australia); Snow, Elizabeth T., E-mail: elizabeth.snow@utas.edu.au [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia)

    2014-11-15

    Arsenic is an environmental toxin which increases skin cancer risk for exposed populations worldwide; however the underlying biomolecular mechanism for arsenic-induced carcinogenesis is complex and poorly defined. Recent investigations show that histone deacetylase and DNA methyltransferase activity is impaired, and epigenetic patterns of gene regulation are consistently altered in cancers associated with arsenic exposure. Expression of the histone deacetylase SIRT1 is altered in solid tumours and haematological malignancies; however its role in arsenic-induced pathology is unknown. In this study we investigated the effect of arsenic on epigenetic regulation of SIRT1 and its targeting microRNA, miR-34a in primary human keratinocytes. Acetylation of histone H4 at lysine 16 (H4K16) increased in keratinocytes exposed to 0.5 μM arsenite [As(III)]; and this was associated with chromatin remodelling at the miR-34a promoter. Moreover, although SIRT1 protein initially increased in these As(III)-exposed cells, after 24 days expression was not significantly different from untreated controls. Extended exposure to low-dose As(III) (0.5 μM; > 5 weeks) compromised the pattern of CpG methylation at SIRT1 and miR-34a gene promoters, and this was associated with altered expression for both genes. We have found that arsenic alters epigenetic regulation of SIRT1 expression via structural reorganisation of chromatin at the miR-34a gene promoter in the initial 24 h of exposure; and over time, through shifts in miR-34a and SIRT1 gene methylation. Taken together, this investigation demonstrates that arsenic produces cumulative disruptions to epigenetic regulation of miR-34a expression, and this is associated with impaired coordination of SIRT1 functional activity. - Highlights: • Submicromolar arsenic concentrations disrupt SIRT1 activity and expression in human keratinocytes. • Arsenic-induced chromatin remodelling at the miR-34a gene promoter is associated with hyperacetylation

  5. Arsenic exposure disrupts epigenetic regulation of SIRT1 in human keratinocytes

    International Nuclear Information System (INIS)

    Arsenic is an environmental toxin which increases skin cancer risk for exposed populations worldwide; however the underlying biomolecular mechanism for arsenic-induced carcinogenesis is complex and poorly defined. Recent investigations show that histone deacetylase and DNA methyltransferase activity is impaired, and epigenetic patterns of gene regulation are consistently altered in cancers associated with arsenic exposure. Expression of the histone deacetylase SIRT1 is altered in solid tumours and haematological malignancies; however its role in arsenic-induced pathology is unknown. In this study we investigated the effect of arsenic on epigenetic regulation of SIRT1 and its targeting microRNA, miR-34a in primary human keratinocytes. Acetylation of histone H4 at lysine 16 (H4K16) increased in keratinocytes exposed to 0.5 μM arsenite [As(III)]; and this was associated with chromatin remodelling at the miR-34a promoter. Moreover, although SIRT1 protein initially increased in these As(III)-exposed cells, after 24 days expression was not significantly different from untreated controls. Extended exposure to low-dose As(III) (0.5 μM; > 5 weeks) compromised the pattern of CpG methylation at SIRT1 and miR-34a gene promoters, and this was associated with altered expression for both genes. We have found that arsenic alters epigenetic regulation of SIRT1 expression via structural reorganisation of chromatin at the miR-34a gene promoter in the initial 24 h of exposure; and over time, through shifts in miR-34a and SIRT1 gene methylation. Taken together, this investigation demonstrates that arsenic produces cumulative disruptions to epigenetic regulation of miR-34a expression, and this is associated with impaired coordination of SIRT1 functional activity. - Highlights: • Submicromolar arsenic concentrations disrupt SIRT1 activity and expression in human keratinocytes. • Arsenic-induced chromatin remodelling at the miR-34a gene promoter is associated with hyperacetylation

  6. Arsenic removal by lime softening

    DEFF Research Database (Denmark)

    Kaosol, T.; Suksaroj, C.; Bregnhøj, Henrik

    This paper focuses on the study of arsenic removal for drinking water by lime softening. The initial arsenic (V) concentration was 500 and 1,000 ug/L in synthetic groundwater. The experiments were performed as batch tests with varying lime dosages and mixing time. For the synthetic groundwater......, arsenic (V) removal increased with increasing lime dosage and mixing time, as well as with the resulting pH. The residual arsenic (V) in all cases was lower than the WHO guideline of 10 ug/L at pH higher than 11.5. Kinetic of arsenic (V) removal can be described by a first-order equation as C1 = C0*e......^-k*t. The relation between the constant (k value) and increasing lime dosage was found to be linear, described by k = 0.0034 (Dlime). The results support a theory from the literature that the arsenic (V) was removed by precipitation af Ca3(AsO4)2. The results obtained in the present study suggest that lime...

  7. Arsenic-resistant bacteria solubilized arsenic in the growth media and increased growth of arsenic hyperaccumulator Pteris vittata L.

    Science.gov (United States)

    Ghosh, Piyasa; Rathinasabapathi, Bala; Ma, Lena Q

    2011-10-01

    The role of arsenic-resistant bacteria (ARB) in arsenic solubilization from growth media and growth enhancement of arsenic-hyperaccumulator Pteris vittata L. was examined. Seven ARB (tolerant to 10 mM arsenate) were isolated from the P. vittata rhizosphere and identified by 16S rRNA sequencing as Pseudomonas sp., Comamonas sp. and Stenotrophomonas sp. During 7-d hydroponic experiments, these bacteria effectively solubilized arsenic from the growth media spiked with insoluble FeAsO₄ and AlAsO₄ minerals (from organic C) by P. vittata may be responsible for As solubilization. Increase in P. vittata root biomass from 1.5-2.2 to 3.4-4.2 g/plant dw by ARB and by arsenic was associated with arsenic-induced plant P uptake. Arsenic resistant bacteria may have potential to enhance phytoremediation of arsenic-contaminated soils by P. vittata. PMID:21840210

  8. Arsenic Toxicity in Male Reproduction and Development.

    Science.gov (United States)

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-12-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity. PMID:26973968

  9. Approaches to Increase Arsenic Awareness in Bangladesh: An Evaluation of an Arsenic Education Program

    Science.gov (United States)

    George, Christine Marie; Factor-Litvak, Pam; Khan, Khalid; Islam, Tariqul; Singha, Ashit; Moon-Howard, Joyce; van Geen, Alexander; Graziano, Joseph H.

    2013-01-01

    The objective of this study was to design and evaluate a household-level arsenic education and well water arsenic testing intervention to increase arsenic awareness in Bangladesh. The authors randomly selected 1,000 study respondents located in 20 villages in Singair, Bangladesh. The main outcome was the change in knowledge of arsenic from…

  10. Arsenic speciation and bioaccessibility in arsenic-contaminated soils: Sequential extraction and mineralogical investigation

    International Nuclear Information System (INIS)

    In this study, a combination of sequential extraction and mineralogical investigation by X-ray diffraction and X-ray photoelectron spectroscopy was employed in order to evaluate arsenic solid-state speciation and bioaccessibility in soils highly contaminated with arsenic from mining and smelting. Combination of these techniques indicated that iron oxides and the weathering products of sulfide minerals played an important role in regulating the arsenic retention in the soils. Higher bioaccessibility of arsenic was observed in the following order; i) arsenic bound to amorphous iron oxides (smelter-2), ii) arsenic associated with crystalline iron oxides and arsenic sulfide phase (smelter-1), and iii) arsenic associated with the weathering products of arsenic sulfide minerals, such as scorodite, orpiment, jarosite, and pyrite (mine). Even though the bioaccessibility of arsenic was very low in the mine soil, its environmental impact could be significant due to its high arsenic concentration and mobility. Highlights: • Combination of sequential extraction and mineralogical investigation was employed. • Arsenic was primarily associated with iron oxides and sulfide minerals in soils. • Bioaccessibility of arsenic was affected by arsenic solid-phase speciation. -- We investigated arsenic solid-state speciation in soils, which is crucial for risk assessment and developing suitable remediation strategies in arsenic contaminated sites

  11. Long non-coding RNA APTR promotes the activation of hepatic stellate cells and the progression of liver fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Fujun [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China); Zheng, Jianjian [Wenzhou Key Laboratory of Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Mao, Yuqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China); Dong, Peihong [Department of Infectious Diseases, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Li, Guojun [Department of Hepatology, Ningbo Yinzhou Second Hospital, Ningbo, 315000 (China); Lu, Zhongqiu [Department of Emergency, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Guo, Chuanyong; Liu, Zhanju [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University School of Medicine, Shanghai, 200072 (China); Fan, Xiaoming, E-mail: ktsqdph@163.com [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China)

    2015-08-07

    In this study, we aimed at assessing a role of Alu-mediated p21 transcriptional regulator (APTR) in hepatofibrogenesis. APTR was upregulated in fibrotic liver samples and activated hepatic stellate cells (HSCs). Knockdown of APTR inhibited the activation of HSCs in vitro and mitigated the accumulation of collagen in vivo. Importantly, APTR silencing could abrogate TGF-β{sub 1}-induced upregulation of α-SMA in HSCs. In addition, inhibition of cell cycle and cell proliferation by APTR knockdown was attenuated by p21 siRNA1 in primary HSCs. Finally, serum APTR levels were increased in patients with liver cirrhosis, indicating a potential biomarker for liver cirrhosis. Collectively, evidence is proposed for a new biological role of APTR in hepatofibrogenesis. - Highlights: • APTR is upregulated in fibrotic liver tissues and activated HSCs. • APTR silencing inhibits HSC activation and the progression of liver fibrosis. • Antifibrotic effect of APTR silencing is achieved by increasing p21.

  12. HER family kinase domain mutations promote tumor progression and can predict response to treatment in human breast cancer

    KAUST Repository

    Boulbes, Delphine R.

    2014-11-11

    Resistance to HER2-targeted therapies remains a major obstacle in the treatment of HER2-overexpressing breast cancer. Understanding the molecular pathways that contribute to the development of drug resistance is needed to improve the clinical utility of novel agents, and to predict the success of targeted personalized therapy based on tumor-specific mutations. Little is known about the clinical significance of HER family mutations in breast cancer. Because mutations within HER1/EGFR are predictive of response to tyrosine kinase inhibitors (TKI) in lung cancer, we investigated whether mutations in HER family kinase domains are predictive of response to targeted therapy in HER2-overexpressing breast cancer. We sequenced the HER family kinase domains from 76 HER2-overexpressing invasive carcinomas and identified 12 missense variants. Patients whose tumors carried any of these mutations did not respond to HER2 directed therapy in the metastatic setting. We developed mutant cell lines and used structural analyses to determine whether changes in protein conformation could explain the lack of response to therapy. We also functionally studied all HER2 mutants and showed that they conferred an aggressive phenotype and altered effects of the TKI lapatinib. Our data demonstrate that mutations in the finely tuned HER kinase domains play a critical function in breast cancer progression and may serve as prognostic and predictive markers.

  13. Feed-in tariffs versus quotas: how to promote renewable s and stimulate technical progress for cost decrease?

    International Nuclear Information System (INIS)

    Incentive schemes for the development of renewable energy sources may focus on quantities (defining national targets and setting up bidding systems, or quota systems providing for green certificate trading), or they may focus on prices (feed-in tariffs). Whatever the system chosen, the role of the public authorities is quite specific: to stimulate technical progress and speed up the technological learning processes so that ultimately renewable energy technologies will be able to compete with conventional technologies, once the environmental costs have been internalized. A comparison of instruments must thus take into account the characteristics of the innovation process and adoption conditions (uncertainties regarding cost curves, learning effects) which means also looking at dynamic efficiency criteria. The paper concludes that a system of feed-in tariffs is more efficient than a bidding system, but highlights the theoretical interest of green certificate trading which must be confirmed through practice, given the influence of market structures and rules on the performance of this type of approach. (author)

  14. Biogeochemical cycling of arsenic in coastal salinized aquifers: Evidence from sulfur isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Yu-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Sheng-Wei [Agricultural Engineering Research Center, Chungli 320, Taiwan, ROC (China); Liu, Chen-Wuing, E-mail: lcw@gwater.agec.ntu.edu.tw [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Pei-Ling [Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Chung-Ho [Institute of Earth Sciences, Academia Sinica, Taipei 115, Taiwan, ROC (China); Maji, Sanjoy Kumar [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2011-10-15

    Arsenic (As) contamination of groundwater, accompanied by critical salinization, occurs in the southwestern coastal area of Taiwan. Statistical analyses and geochemical calculations indicate that a possible source of aqueous arsenic is the reductive dissolution of As-bearing iron oxyhydroxides. There are few reports of the influence of sulfate-sulfide redox cycling on arsenic mobility in brackish groundwater. We evaluated the contribution of sulfate reduction and sulfide re-oxidation on As enrichment using {delta}{sup 34}S{sub [SO{sub 4]}} and {delta}{sup 18}O{sub [SO{sub 4]}} sulfur isotopic analyses of groundwater. Fifty-three groundwater samples were divided into groups of high-As content and salinized (Type A), low-As and non-salinized (Type B), and high-As and non-salinized (Type C) groundwaters, based on hydro-geochemical analysis. The relatively high enrichment of {sup 34}S{sub [SO{sub 4]}} and {sup 18}O{sub [SO{sub 4]}} present in Type A, caused by microbial-mediated reduction of sulfate, and high {sup 18}O enrichment factor ({epsilon}{sub [SO{sub 4-H{sub 2O]}}}), suggests that sulfur disproportionation is an important process during the reductive dissolution of As-containing iron oxyhydroxides. Limited co-precipitation of ion-sulfide increased the rate of As liberation under anaerobic conditions. In contrast to this, Type B and Type C groundwater samples showed high {delta}{sup 18}O{sub [SO{sub 4]}} and low {delta}{sup 34}S{sub [SO{sub 4]}} values under mildly reducing conditions. Base on {sup 18}O mass balance calculations, the oxide sources of sulfate are from infiltrated atmospheric O{sub 2}, caused by additional recharge of dissolved oxygen and sulfide re-oxidation. The anthropogenic influence of extensive pumping also promotes atmospheric oxygen entry into aquifers, altering redox conditions, and increasing the rate of As release into groundwater. - Highlights: {yields} Seawater intrusion and elevated As are the main issues of groundwater in Taiwan

  15. Androgen receptor regulated microRNA miR-182-5p promotes prostate cancer progression by targeting the ARRDC3/ITGB4 pathway.

    Science.gov (United States)

    Yao, Jingjing; Xu, Chen; Fang, Ziyu; Li, Yaoming; Liu, Houqi; Wang, Yue; Xu, Chuanliang; Sun, Yinghao

    2016-05-20

    MicroRNAs (miRNAs) are important endogenous gene regulators that play key roles in prostate cancer development and metastasis. However, specific miRNA expression patterns in prostate cancer tissues from Chinese patients remain largely unknown. In this study, we compared miRNA expression patterns in 65 pairs of prostate cancer and para-cancer tissues by RNA sequencing and found that miR-182-5p was the most up-regulated miRNA in prostate cancer tissues. The result was validated using realtime PCR in 18 pairs of prostate cancer and para-cancer tissues. In in vitro analysis, it was confirmed that miR-182-5p promotes prostate cancer cell proliferation, invasion and migration and inhibit apoptosis. In addition, the androgen receptor directly regulated the transcription of miR-182-5p, which could target to the 3'UTR of ARRDC3 mRNA and affect the expression of ARRDC3 and its downstream gene ITGB4. For the in vivo experiment, miR-182-5p overexpression also promoted the growth and progression of prostate cancer tumors. In this regard, we suggest that miR-182-5p may be a key androgen receptor-regulated factor that contributes to the development and metastasis of Chinese prostate cancers and may be a potential target for the early diagnosis and therapeutic studies of prostate cancer. PMID:27109471

  16. Regeneration of Commercial SCR Catalysts: Probing the Existing Forms of Arsenic Oxide.

    Science.gov (United States)

    Li, Xiang; Li, Junhua; Peng, Yue; Si, Wenzhe; He, Xu; Hao, Jiming

    2015-08-18

    To investigate the poisoning and regeneration of SCR catalysts, fresh and arsenic-poisoned commercial V2O5-WO3/TiO2 catalysts are researched in the context of deactivation mechanisms and regeneration technology. The results indicate that the forms of arsenic oxide on the poisoned catalyst are related to the proportion of arsenic (As) on the catalyst. When the surface coverage of (V+W+As) is lower than 1, the trivalent arsenic species (As(III)) is the major component, and this species prefers to permeate into the bulk-phase channels. However, at high As concentrations, pentavalent arsenic species (As(IV)) cover the surface of the catalyst. Although both arsenic species lower the NOx conversion, they affect the formation of N2O differently. In particular, N2O production is limited when trivalent arsenic species predominate, which may be related to As2O3 clogging the pores of the catalyst. In contrast, the pentavalent arsenic oxide species (As2O5) possess several As-OH groups. These As-OH groups could not only enhance the ability of the catalyst to become reduced, but also provide several Brønsted acid sites with weak thermal stability that promote the formation of N2O. Finally, although our novel Ca(NO3)2-based regeneration method cannot completely remove As2O3 from the micropores of the catalyst, this approach can effectively wipe off surface arsenic oxides without a significant loss of the catalyst's active components. PMID:26186082

  17. Attenuation of arsenic in a karst subterranean stream and correlation with geochemical factors: a case study at Lihu, South China.

    Science.gov (United States)

    Zhang, Liankai; Yang, Hui; Tang, Jiansheng; Qin, Xiaoqun; Yu, Au Yik

    2014-11-01

    Arsenic (As) pollutants generated by human activities in karst areas flow into subterranean streams and contaminate groundwater easily because of the unique hydrogeological characteristics of karst areas. To elucidate the reaction mechanisms of arsenic in karst subterranean streams, physical-chemical analysis was conducted by an inductively coupled plasma mass spectrometer and an X-ray fluorescence spectrometer. The results show that inorganic species account for most of the total arsenic, whereas organic arsenic is not detected or occurs in infinitesimal amounts. As(III) accounts for 51.0%±9.9% of the total inorganic arsenic. Arsenic attenuation occurs and the attenuation rates of total As, As(III) and As(V) in the Lihu subterranean stream are 51%, 36% and 59%, respectively. To fully explain the main geochemical factors influencing arsenic attenuation, SPSS 13.0 and CANOCO 4.5 bundled with CanoDraw for Windows were used for simple statistical analysis and redundancy analysis (RDA). Eight main factors, i.e., sediment iron (SFe), sediment aluminum (SAl), sediment calcium (SCa), sediment organic matter (SOM), sediment manganese (SMn), water calcium (WCa(2+)), water magnesium (WMg(2+)), and water bicarbonate ion (WHCO3(-)) were extracted from thirteen indicators. Their impacts on arsenic content rank as: SFe>SCa>WCa(2+)>SAl>WHCO3(-)>SMn>SOM>WMg(2+). Of these factors, SFe, SAl, SCa, SOM, SMn, WMg(2+) and WCa(2+) promote arsenic attenuation, whereas WHCO3(-) inhibits it. Further investigation revealed that the redox potential (Eh) and pH are adverse to arsenic removal. The dramatic distinction between karst and non-karst terrain is that calcium and bicarbonate are the primary factors influencing arsenic migration in karst areas due to the high calcium concentration and alkalinity of karst water. PMID:25458676

  18. Identification of the third binding site of arsenic in human arsenic (III methyltransferase.

    Directory of Open Access Journals (Sweden)

    Xiangli Li

    Full Text Available Arsenic (III methyltransferase (AS3MT catalyzes the process of arsenic methylation. Each arsenite (iAs(3+ binds to three cysteine residues, methylarsenite (MMA(3+ binds to two, and dimethylarsenite (DMA(3+ binds to one. However, only two As-binding sites (Cys156 and Cys206 have been confirmed on human AS3MT (hAS3MT. The third As-binding site is still undefined. Residue Cys72 in Cyanidioschyzon merolae arsenite S-adenosylmethyltransferase (CmArsM may be the third As-binding site. The corresponding residue in hAS3MT is Cys61. Functions of Cys32, Cys61, and Cys85 in hAS3MT are unclear though Cys32, Cys61, and Cys85 in rat AS3MT have no effect on the enzyme activity. This is why the functions of Cys32, Cys61, and Cys85 in hAS3MT merit investigation. Here, three mutants were designed, C32S, C61S, and C85S. Their catalytic activities and conformations were determined, and the catalytic capacities of C156S and C206S were studied. Unlike C85S, mutants C32S and C61S were completely inactive in the methylation of iAs(3+ and active in the methylation of MMA(3+. The catalytic activity of C85S was also less pronounced than that of WT-hAS3MT. All these findings suggest that Cys32 and Cys61 markedly influence the catalytic activity of hAS3MT. Cys32 and Cys61 are necessary to the first step of methylation but not to the second. Cys156 and Cys206 are required for both the first and second steps of methylation. The S(C32 is located far from arsenic in the WT-hAS3MT-SAM-As model. The distances between S(C61 and arsenic in WT-hAS3MT-As and WT-hAS3MT-SAM-As models are 7.5 Å and 4.1 Å, respectively. This indicates that SAM-binding to hAS3MT shortens the distance between S(C61 and arsenic and promotes As-binding to hAS3MT. This is consistent with the fact that SAM is the first substrate to bind to hAS3MT and iAs is the second. Model of WT-hAS3MT-SAM-As and the experimental results indicate that Cys61 is the third As-binding site.

  19. Arsenic speciation in saliva of acute promyelocytic leukemia patients undergoing arsenic trioxide treatment

    OpenAIRE

    Chen, Baowei; Cao, Fenglin; Yuan, Chungang; Lu, Xiufen; Shen, Shengwen; Zhou, Jin; Le, X Chris

    2013-01-01

    Arsenic trioxide has been successfully used as a therapeutic in the treatment of acute promyelocytic leukemia (APL). Detailed monitoring of the therapeutic arsenic and its metabolites in various accessible specimens of APL patients can contribute to improving treatment efficacy and minimizing arsenic-induced side effects. This article focuses on the determination of arsenic species in saliva samples from APL patients undergoing arsenic treatment. Saliva samples were collected from nine APL pa...

  20. Arsenic Exposure and Toxicology: A Historical Perspective

    OpenAIRE

    Hughes, Michael F.; Beck, Barbara D.; Chen, Yu; Lewis, Ari S.; Thomas, David J

    2011-01-01

    The metalloid arsenic is a natural environmental contaminant to which humans are routinely exposed in food, water, air, and soil. Arsenic has a long history of use as a homicidal agent, but in the past 100 years arsenic, has been used as a pesticide, a chemotherapeutic agent and a constituent of consumer products. In some areas of the world, high levels of arsenic are naturally present in drinking water and are a toxicological concern. There are several structural forms and oxidation states o...

  1. Arsenic in contaminated soil and river sediment

    Energy Technology Data Exchange (ETDEWEB)

    Bombach, G. (Freiberg Univ. of Mining and Technology, Inst. of Mineralogy, Geochemistry and Ore Deposits, Freiberg (Germany)); Pierra, A. (Freiberg Univ. of Mining and Technology, Inst. of Mineralogy, Geochemistry and Ore Deposits, Freiberg (Germany)); Klemm, W. (Freiberg Univ. of Mining and Technology, Inst. of Mineralogy, Geochemistry and Ore Deposits, Freiberg (Germany))

    1994-09-01

    Different areas in the Erzgebirge mountains are contaminated by high arsenic concentration which is caused by the occurrence of ore and industrial sources. The study showed clearly a high concentration of arsenic in the surface and under soil (A and B horizons) in the Freiberg district. The distribution of the arsenic concentration in the area, the content of water soluble arsenic, the several oxidation states (As[sup 3+], As[sup 5+]) and the bonding types have been analyzed. (orig.)

  2. Arsenic in contaminated soil and river sediment

    International Nuclear Information System (INIS)

    Different areas in the Erzgebirge mountains are contaminated by high arsenic concentration which is caused by the occurrence of ore and industrial sources. The study showed clearly a high concentration of arsenic in the surface and under soil (A and B horizons) in the Freiberg district. The distribution of the arsenic concentration in the area, the content of water soluble arsenic, the several oxidation states (As3+, As5+) and the bonding types have been analyzed. (orig.)

  3. The effects of arsenic or the combination of arsenic and radiation exposure is enhanced through the overexpression of the GSTO family member p28

    International Nuclear Information System (INIS)

    Full text: p28 is a member of the GST omega superfamily and has dehydroascorbate reductase, GST, and glutaredoxin activities. Furthermore, p28 is the rate-limiting enzyme in the bio-transformation of arsenic. The monomethyl arsenous reducatase activity of p28 produces dimethylarseniate, the most toxic form of arsenic. We investigated how p28 modulated arsenic cellular sensitivity in two mammalian models: 1) in LY-ar and LY-as cells where p28 is over-expressed and not expressed, respectively; and 2) in stably transfected A549 cells where p28 is over-expressed via a CMV promoter. The LY-ar mouse lymphoma cell line is radio and chemo-resistant and apoptosis refractory, whereas the parental cell line, LY-as, is radiosensitive and apoptotically permissive. In addition, we studied the effect of arsenic as a radiosensitizer in both cell systems. In LY-ar cells arsenic induced a dose- and time- dependent increase in apoptosis, which is comparable to that seen in LY-as cells. Arsenic plus 2.5Gy radiation induced apoptosis in LY-ar cells, which was more than additive. Survival in LY-ar cells was reduced to that of LY-as cells as well as p28 overexpression induced G2/M arrest in A549 cells and the combination of radiation with arsenic decreased the clonogenic survival of both the A549 and A549-p28 cells but the effect is more pronounced in the A549-P28 cell line. A549 and A549-p28 cells did not show a differential response to Taxol, which induces G2/M arrest and cell death via an inhibition of tubulin depolarization. Arsenic modulated the level of reduced GSH in both cell systems in a dose- and time- dependent manner, which correlated with survival outcome. This study illustrated that arsenic acts as a radiosensitizer and p28 augmented the potential of arsenic in inducing apoptosis, G2/M arrest, and radiosensitization. Further studies are underway to examine the bio-chemical pathways involved in arsenic-mediated cell death and the role of p28 therein

  4. 21 CFR 556.60 - Arsenic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Arsenic. 556.60 Section 556.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND... New Animal Drugs § 556.60 Arsenic. Tolerances for total residues of combined arsenic (calculated as...

  5. Arsenic removal from industrial effluent through electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, N. [Central Electrochemical Research Inst., Karaikudi (India). Dept. of Pollution Control; Madhavan, K. [Coimbatore Inst. of Technology, Coimbatore (India). Dept. of Chemistry

    2001-05-01

    In the present investigation, it is attempted to remove arsenic from smelter industrial wastewater through electro-coagulation. Experiments covering a wide range of operating conditions for removal of the arsenic present in the smelter wastewater are carried out in a batch electrochemical reactor. It has been observed from the present work that arsenic can be removed effectively through electrocoagulation. (orig.)

  6. Chloride sublimation of gold-arsenic concentrates

    International Nuclear Information System (INIS)

    Present article is devoted to chloride sublimation of gold-arsenic concentrates. The results of studies of chloride sublimation of gold-arsenic comprising concentrates of Chore deposit of Tajikistan are considered. It is found that by application sodium chloride for gold-arsenic comprising concentrates it is possible to extract gold and silver from flotation concentrates.

  7. Progress on DMD Gene Promoter in the Role of Gene Therapy%DMD启动子在基因治疗中作用的研究进展

    Institute of Scientific and Technical Information of China (English)

    李江超; 蔡望伟; 盛文利

    2009-01-01

    假肥大型进行性肌营养不良(DMD)是一类X连锁隐性退行性肌肉萎缩病.目前,关于DMD基因外显子缺失,内含子断裂点以及所编码dystmphin蛋白的结构已经明确,这对DMD的临床诊断有很大价值;但对于基凶治疗来说,明确DMD基因启动子的顺式元件以及反式因子的结构及相互作用关系是十分重要的,这些元件的相互作用对于dystrophin蛋白的转录水平及表达起关键的调节作用;研究表明,人工合成的DMD肌启动子活性比生物体内DMD基因启动子活性高,找出启动子关键元件构建特异性高效启动子,将其应用于基因治疗,这是一条新的途径.%Duchenne muscular dystrophy is X-linked recessive disorders which result in a distinctive pattern and progressive muscle wasting.At present,on the DMD gene deletion in exon containing break-point,as well as the coding of the dystrophin protein has a clear structure.which is of great value to the clinical diagnosis of DMD.Furthermore,for gene therapy,more development is needed for DMD gene promoter Cis-acting elements and the trans-factor structure and the relationship between these components,which play a key role in the regulation protein expression and the transfer rate;Study showed that artificial muscle promoter in vivo biological activity is more than the gene itself promoter,The relevant sub-components will be found to stan building a hish-specific promoter,if applied,it is a new way for gene therapy.

  8. Arsenic in groundwaters in the Northern Appalachian Mountain belt: A review of patterns and processes

    Science.gov (United States)

    Peters, Stephen C.

    2008-07-01

    Naturally occurring arsenic in the bedrock of the Northern Appalachian Mountain belt was first recognized in the late 19th century. The knowledge of the behavior of arsenic in groundwater in this region has lagged behind nearly a century, with the popular press reporting on local studies in the early 1980s, and most peer-reviewed research articles on regional patterns conducted and written in the late 1990s and early 2000s. Research reports have shown that within this high arsenic region, between 6% and 22% of households using private drinking water wells contain arsenic in excess of 10 µg/L, the United States Environmental Protection Agency's maximum contaminant level. In nearly all reports, arsenic in drinking water was derived from naturally occurring geologic sources, typically arsenopyrite, substituted sulfides such as arsenian pyrite, and nanoscale minerals such as westerveldite. In most studies, arsenic concentrations in groundwater were controlled by pH dependent adsorption to mineral surfaces, most commonly iron oxide minerals. In some cases, reductive dissolution of iron minerals has been shown to increase arsenic concentrations in groundwater, more commonly associated with anthropogenic activities such as landfills. Evidence of nitrate reduction promoting the presence of arsenic(V) and iron(III) minerals in anoxic environments has been shown to occur in surface waters, and in this manuscript we show this process perhaps applies to groundwater. The geologic explanation for the high arsenic region in the Northern Appalachian Mountain belt is most likely the crustal recycling of arsenic as an incompatible element during tectonic activity. Accretion of multiple terranes, in particular Avalonia and the Central Maine Terrane of New England appear to be connected to the presence of high concentrations of arsenic. Continued tectonic activity and recycling of these older terranes may also be responsible for the high arsenic observed in the Triassic rift basins

  9. Arsenic – Poison or medicine?

    Directory of Open Access Journals (Sweden)

    Karolina Kulik-Kupka

    2016-04-01

    Full Text Available Arsenic (As is commonly known as a poison. Only a few people know that As has also been widely used in medicine. In the past years As and its compounds were used as a medicine for the treatment of such diseases as diabetes, psoriasis, syphilis, skin ulcers and joint diseases. Nowadays As is also used especially in the treatment of patients with acute promyelocytic leukemia. The International Agency for Research on Cancer (IARC has recognized arsenic as an element with carcinogenic effect evidenced by epidemiological studies, but as previously mentioned it is also used in the treatment of neoplastic diseases. This underlines the specificity of the arsenic effects. Arsenic occurs widely in the natural environment, for example, it is present in soil and water, which contributes to its migration to food products. Long exposure to this element may lead to liver damages and also to changes in myocardium. Bearing in mind that such serious health problems can occur, monitoring of the As presence in the environmental media plays a very important role. In addition, the occupational risk of As exposure in the workplace should be identified and checked. Also the standards for As presence in food should be established. This paper presents a review of the 2015 publications based on the Medical database like PubMed and Polish Medical Bibliography. It includes the most important information about arsenic in both forms, poison and medicine. Med Pr 2016;67(1:89–96

  10. Demethylation of the miR-146a promoter by 5-Aza-2’-deoxycytidine correlates with delayed progression of castration-resistant prostate cancer

    International Nuclear Information System (INIS)

    Androgen deprivation therapy is the primary strategy for the treatment of advanced prostate cancer; however, after an initial regression, most patients will inevitably develop a fatal androgen-independent tumor. Therefore, understanding the mechanisms of the transition to androgen independence prostate cancer is critical to identify new ways to treat older patients who are ineligible for conventional chemotherapy. The effects of 5-Aza-2’-deoxycytidine (5-Aza-CdR) on the viability and the apoptosis of the androgen-dependent (LNCaP) and androgen-independent (PC3) cell lines were examined by MTS assay and western blot analysis for the activation of caspase-3. The subcutaneous LNCaP xenografts were established in a nude mice model. MiR-146a and DNMTs expressions were analyzed by qRT-PCR and DNA methylation rates of LINE-1 were measured by COBRA-IRS to determine the global DNA methylation levels. The methylation levels of miR-146a promoter region in the different groups were quantified by the bisulfite sequencing PCR (BSP) assay. We validated that 5-Aza-CdR induced cell death and increased miR-146a expression in both LNCaP and PC3 cells. Notably, the expression of miR-146a in LNCaP cells was much higher than in PC3 cells. MiR-146a inhibitor was shown to suppress apoptosis in 5-Aza-CdR-treated cells. In a castrate mouse LNCaP xenograft model, 5-Aza-CdR significantly suppressed the tumors growth and also inhibited prostate cancer progression. Meanwhile, miR-146a expression was significantly enhanced in the tumor xenografts of 5-Aza-CdR-treated mice and the androgen-dependent but not the androgen-independent stage of castrated mice. In particular, the expression of miR-146a was significantly augmented in both stages of the combined treatment (castration and 5-Aza-CdR). Additionally, the methylation percentage of the two CpG sites (−444 bp and −433 bp), which were around the NF-κB binding site at miR-146a promoter, showed the lowest methylation levels among all Cp

  11. Whole-house arsenic water treatment provided more effective arsenic exposure reduction than point-of-use water treatment at New Jersey homes with arsenic in well water

    OpenAIRE

    Spayd, Steven E.; Robson, Mark G.; Buckley, Brian T.

    2014-01-01

    A comparison of the effectiveness of whole house (point-of-entry) and point-of-use arsenic water treatment systems in reducing arsenic exposure from well water was conducted. The non-randomized observational study recruited 49 subjects having elevated arsenic in their residential home well water in New Jersey. The subjects obtained either point-of-entry or point-of-use arsenic water treatment. Prior ingestion exposure to arsenic in well water was calculated by measuring arsenic concentrations...

  12. Growth factor and Th2 cytokine signaling pathways converge at STAT6 to promote arginase expression in progressive experimental visceral leishmaniasis.

    Directory of Open Access Journals (Sweden)

    E Yaneth Osorio

    2014-06-01

    Full Text Available Host arginase 1 (arg1 expression is a significant contributor to the pathogenesis of progressive visceral leishmaniasis (VL, a neglected tropical disease caused by the intracellular protozoan Leishmania donovani. Previously we found that parasite-induced arg1 expression in macrophages was dependent on STAT6 activation. Arg1 expression was amplified by, but did not require, IL-4, and required de novo synthesis of unknown protein(s. To further explore the mechanisms involved in arg1 regulation in VL, we screened a panel of kinase inhibitors and found that inhibitors of growth factor signaling reduced arg1 expression in splenic macrophages from hamsters with VL. Analysis of growth factors and their signaling pathways revealed that the Fibroblast Growth Factor Receptor 1 (FGFR-1 and Insulin-like Growth Factor 1 Receptor (IGF-1R and a number of downstream signaling proteins were activated in splenic macrophages isolated from hamsters infected with L. donovani. Recombinant FGF-2 and IGF-1 increased the expression of arg1 in L. donovani infected hamster macrophages, and this induction was augmented by IL-4. Inhibition of FGFR-1 and IGF-1R decreased arg1 expression and restricted L. donovani replication in both in vitro and ex vivo models of infection. Inhibition of the downstream signaling molecules JAK and AKT also reduced the expression of arg1 in infected macrophages. STAT6 was activated in infected macrophages exposed to either FGF-2 or IGF-1, and STAT6 was critical to the FGFR-1- and IGF-1R-mediated expression of arg1. The converse was also true as inhibition of FGFR-1 and IGF-1R reduced the activation of STAT6 in infected macrophages. Collectively, these data indicate that the FGFR/IGF-1R and IL-4 signaling pathways converge at STAT6 to promote pathologic arg1 expression and intracellular parasite survival in VL. Targeted interruption of these pathological processes offers an approach to restrain this relentlessly progressive disease.

  13. Arsenic mobility in contaminated lake sediments

    International Nuclear Information System (INIS)

    An arsenic contaminated lake sediment near a landfill in Maine was used to characterize the geochemistry of arsenic and assess the influence of environmental conditions on its mobility. A kinetic model was developed to simulate the leaching ability of arsenic in lake sediments under different environmental conditions. The HM1D chemical transport model was used to model the column experiments and determine the rates of arsenic mobility from the sediment. Laboratory studies provided the information to construct a conceptual model to demonstrate the mobility of arsenic in the lake sediment. The leaching ability of arsenic in lake sediments greatly depends on the flow conditions of ground water and the geochemistry of the sediments. Large amounts of arsenic were tightly bound to the sediments. The amount of arsenic leaching out of the sediment to the water column was substantially decreased due to iron/arsenic co-precipitation at the water-sediment interface. Overall, it was found that arsenic greatly accumulated at the ground water/lake interface and it formed insoluble precipitates. - Arsenic accumulates at the ground water/lake interface, where it forms insoluble precipitates

  14. Neutron activation analysis of arsenic in Greece

    International Nuclear Information System (INIS)

    Arsenic is considered a toxic trace element for plant, animal, and human organisms. Arsenic and certain arsenic compounds have been listed as carcinogens by the U.S. Environmental Protection Agency. Arsenic is emitted in appreciable quantities into the atmosphere by coal combustion and the production of cement. Arsenic enters the aquatic environment through industrial activities such as smelting of metallic ores, metallurgical glassware, and ceramics as well as insecticide production and use. Neutron activation analysis (NAA) is a very sensitive, precise, and accurate method for determining arsenic. This paper is a review of research studies of arsenic in the Greek environment by NAA performed at our radioanalytical laboratory. The objectives of these studies were (a) to determine levels of arsenic concentrations in environmental materials, (b) to pinpoint arsenic pollution sources and estimate the extent of arsenic pollution, and (c) to find out whether edible marine organisms from the gulfs of Greece receiving domestic, industrial, and agricultural wastes have elevated concentrations of arsenic in their tissues that could render them dangerous for human consumption

  15. Removal processes for arsenic in constructed wetlands.

    Science.gov (United States)

    Lizama A, Katherine; Fletcher, Tim D; Sun, Guangzhi

    2011-08-01

    Arsenic pollution in aquatic environments is a worldwide concern due to its toxicity and chronic effects on human health. This concern has generated increasing interest in the use of different treatment technologies to remove arsenic from contaminated water. Constructed wetlands are a cost-effective natural system successfully used for removing various pollutants, and they have shown capability for removing arsenic. This paper reviews current understanding of the removal processes for arsenic, discusses implications for treatment wetlands, and identifies critical knowledge gaps and areas worthy of future research. The reactivity of arsenic means that different arsenic species may be found in wetlands, influenced by vegetation, supporting medium and microorganisms. Despite the fact that sorption, precipitation and coprecipitation are the principal processes responsible for the removal of arsenic, bacteria can mediate these processes and can play a significant role under favourable environmental conditions. The most important factors affecting the speciation of arsenic are pH, alkalinity, temperature, dissolved oxygen, the presence of other chemical species--iron, sulphur, phosphate--,a source of carbon, and the wetland substrate. Studies of the microbial communities and the speciation of arsenic in the solid phase using advanced techniques could provide further insights on the removal of arsenic. Limited data and understanding of the interaction of the different processes involved in the removal of arsenic explain the rudimentary guidelines available for the design of wetlands systems. PMID:21549410

  16. Introducing Simple Detection of Bioavailable Arsenic at Rafaela (Santa Fe Province, Argentina Using the ARSOlux Biosensor

    Directory of Open Access Journals (Sweden)

    Konrad Siegfried

    2015-05-01

    Full Text Available Numerous articles have reported the occurrence of arsenic in drinking water in Argentina, and the resulting health effects in severely affected regions of the country. Arsenic in drinking water in Argentina is largely naturally occurring due to elevated background content of the metalloid in volcanic sediments, although, in some regions, mining can contribute. While the origin of arsenic release has been discussed extensively, the problem of drinking water contamination has not yet been solved. One key step in progress towards mitigation of problems related with the consumption of As-containing water is the availability of simple detection tools. A chemical test kit and the ARSOlux biosensor were evaluated as simple analytical tools for field measurements of arsenic in the groundwater of Rafaela (Santa Fe, Argentina, and the results were compared with ICP-MS and HPLC-ICP-MS measurements. A survey of the groundwater chemistry was performed to evaluate possible interferences with the field tests. The results showed that the ARSOlux biosensor performed better than the chemical field test, that the predominant species of arsenic in the study area was arsenate and that arsenic concentration in the studied samples had a positive correlation with fluoride and vanadium, and a negative one with calcium and iron.

  17. Introducing Simple Detection of Bioavailable Arsenic at Rafaela (Santa Fe Province, Argentina) Using the ARSOlux Biosensor.

    Science.gov (United States)

    Siegfried, Konrad; Hahn-Tomer, Sonja; Koelsch, Andreas; Osterwalder, Eva; Mattusch, Juergen; Staerk, Hans-Joachim; Meichtry, Jorge M; De Seta, Graciela E; Reina, Fernando D; Panigatti, Cecilia; Litter, Marta I; Harms, Hauke

    2015-05-01

    Numerous articles have reported the occurrence of arsenic in drinking water in Argentina, and the resulting health effects in severely affected regions of the country. Arsenic in drinking water in Argentina is largely naturally occurring due to elevated background content of the metalloid in volcanic sediments, although, in some regions, mining can contribute. While the origin of arsenic release has been discussed extensively, the problem of drinking water contamination has not yet been solved. One key step in progress towards mitigation of problems related with the consumption of As-containing water is the availability of simple detection tools. A chemical test kit and the ARSOlux biosensor were evaluated as simple analytical tools for field measurements of arsenic in the groundwater of Rafaela (Santa Fe, Argentina), and the results were compared with ICP-MS and HPLC-ICP-MS measurements. A survey of the groundwater chemistry was performed to evaluate possible interferences with the field tests. The results showed that the ARSOlux biosensor performed better than the chemical field test, that the predominant species of arsenic in the study area was arsenate and that arsenic concentration in the studied samples had a positive correlation with fluoride and vanadium, and a negative one with calcium and iron. PMID:26006123

  18. 氢化物发生-原子荧光光谱法测定合金钢及合金中痕量元素铅、锡、砷、锑、铋的进展%Determination Progress of Trace Elements (Lead, Tin, Arsenic, Antimony, Bismuth)in Staliness Steel Alloys by HF-AFS

    Institute of Scientific and Technical Information of China (English)

    赵艳兵; 刘爱坤; 戴学谦; 王珺

    2011-01-01

    通过对近年来有关氢化物发生-原子荧光光谱法在复杂基体体系中痕量元素检测方面的资料总结,阐述了氢化物发生-原子荧光光谱法分析过程中的干扰类型、干扰机理及消除干扰的措施,对其在合金钢及合金中痕量元素铅、锡、砷、锑、铋测定中的应用进展作了评述,并对氢化物发生-原子荧光光谱法的发展前景提出了展望。%This paper presented a data summary of determination of trace elements in a complex matrix system by HG-AFS,covering the recent years. The interference type, interference mechanism and measures to eliminate interference of HG-AFS were also described. We reviewed the progress of the determination application of the Staliness Steel Alloys of trace elements, tin, lead, arsenic, antimony bismuth.We also discussed the HG-AFS development prospect.

  19. Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

    Science.gov (United States)

    Cao, Menghua; Ye, Yuanyao; Chen, Jing; Lu, Xiaohua

    2016-02-01

    The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign. PMID:26476769

  20. Selective hyaluronan-CD44 signaling promotes miRNA-21 expression and interacts with vitamin D function during cutaneous squamous cell carcinomas progression following UV irradiation

    Directory of Open Access Journals (Sweden)

    Lilly YW Bourguignon

    2015-05-01

    Full Text Available Hyaluronan (HA, the major extracellular matrix component, is often anchored to CD44 isoforms, a family of structurally/functionally important cell surface receptors. Our recent results indicate that UV irradiation (UVR-induced cutaneous squamous cell carcinomas (SCC overexpress a variety of CD44 variant isoforms (CD44v, with different CD44v isoforms appear to confer malignant SCC properties. UVR also stimulates HA degradation in epidermal keratinocytes. Both large HA polymers and their UVR-induced catabolic products (small HA selectively activate CD44 isoform-mediated cellular signaling in normal keratinocytes and SCC cells, with all of the downstream processes being mediated by RhoGTPases (e.g., RhoA and Rac1. Importantly, we found that the hormonally active form of vitamin D (1,25(OH2D3 not only prevents the UVR-induced small HA activation of abnormal keratinocyte behavior and SCC progression, but also enhances large HA stimulation of normal keratinocyte activities and epidermal function(s. Furthermore, we found that HA and its UVR-induced catabolic products (e.g., large and small HA selectively activate CD44-mediated Rac and RhoA signaling. Specifically, large HA-CD44 interaction promotes Rac/PKNγ-dependent normal keratinocyte differentiation, DNA repair and keratinocyte survival. Conversely, small HA-CD44v isoform interaction stimulates RhoA/ROK-dependent NFκB signaling and microRNA-21 (miR-21 production, leading to inflammation, proliferation (following acute UVR response and SCC progression (following chronic UVR exposure. Active vitamin D inhibits small HA-CD44v-mediated RhoA/ROK signaling and SCC progression; and it also enhances large HA-CD44-mediated differentiation, DNA repair and normal epidermal function. Selective applications of large HA and vitamin D will be used to improve the UVR-induced HA (small vs. large HA-CD44 isoform interaction with RhoGTPase signaling and skin inflammation as a potential therapeutic treatment for skin

  1. Activity of the AtMRP3 promoter in transgenic Arabidopsis thaliana and Nicotiana tabacum plants is increased by cadmium, nickel, arsenic, cobalt and lead but not by zinc and iron

    NARCIS (Netherlands)

    Zientara, K.; Wawrzynska, A.; Lukomska, J.; Lopez Moya, J.R.; Liszewska, F.; Assuncao, A.G.L.; Aarts, M.G.M.; Sirko, A.

    2009-01-01

    Characterization of the function, regulation and metal-specificity of metal transporters is one of the basic steps needed for the understanding of transport and accumulation of toxic metals and metalloids by plants. In this work GUS was used as a reporter for monitoring the activity of the promoter

  2. Oxidative stress and hepatic stellate cell activation are key events in arsenic induced liver fibrosis in mice

    International Nuclear Information System (INIS)

    Arsenic is an environmental toxicant and carcinogen. Exposure to arsenic is associated with development of liver fibrosis and portal hypertension through ill defined mechanisms. We evaluated hepatic fibrogenesis after long term arsenic exposure in a murine model. BALB/c mice were exposed to arsenic by daily gavages of 6 μg/gm body weight for 1 year and were evaluated for markers of hepatic oxidative stress and fibrosis, as well as pro-inflammatory, pro-apoptotic and pro-fibrogenic factors at 9 and 12 months. Hepatic NADPH oxidase activity progressively increased in arsenic exposure with concomitant development of hepatic oxidative stress. Hepatic steatosis with occasional collection of mononuclear inflammatory cells and mild portal fibrosis were the predominant liver lesion observed after 9 months of arsenic exposure, while at 12 months, the changes included mild hepatic steatosis, inflammation, necrosis and significant fibrosis in periportal areas. The pathologic changes in the liver were associated with markers of hepatic stellate cells (HSCs) activation, matrix reorganization and fibrosis including α-smooth muscle actin, transforming growth factor-β1, PDGF-Rβ, pro-inflammatory cytokines and enhanced expression of tissue inhibitor of metalloproteinase-1 and pro(α) collagen type I. Moreover, pro-apoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated along with increased number of TUNEL positive hepatocytes in liver of arsenic exposed mice. Furthermore, HSCs activation due to increased hepatic oxidative stress observed after in vivo arsenic exposure was recapitulated in co-culture model of isolated HSCs and hepatocytes exposed to arsenic. These findings have implications not only for the understanding of the pathology of arsenic related liver fibrosis but also for the design of preventive strategies in chronic arsenicosis.

  3. Renal, hepatic, pulmonary and adrenal tumors induced by prenatal inorganic arsenic followed by dimethylarsinic acid in adulthood in CD1 mice

    OpenAIRE

    Tokar, Erik J.; Diwan, Bhalchandra A.; Waalkes, Michael P.

    2011-01-01

    Inorganic arsenic, an early life carcinogen in humans and mice, can initiate lesions promotable by other agents in later life. The biomethylation product of arsenic, dimethylarsinic acid (DMA), is a multi-site tumor promoter. Thus, pregnant CD1 mice were given drinking water (0 or 85 ppm arsenic) from gestation day 8 to 18 and after weaning male offspring received DMA (0 or 200 ppm; drinking water) for up to 2 years. No renal tumors occurred in controls or DMA alone treated mice while gestati...

  4. Possible mechanisms for arsenic-induced proliferative diseases

    Energy Technology Data Exchange (ETDEWEB)

    Wetterhahn, K.E.; Dudek, E.J.; Shumilla, J.A. [Dartmouth College and Medical School, Hanover, NH (United States)] [and others

    1996-12-31

    Possible mechanisms for cardiovascular diseases and cancers which have been observed on chronic exposure to arsenic have been investigated. We tested the hypothesis that nonlethal levels of arsenic are mitogenic, cause oxidative stress, increase nuclear translocation of trans-acting factors, and increase expression of genes involved in proliferation. Cultured porcine vascular (from aorta) endothelial cells were used as a model cell system to study the effects of arsenic on the target cells for cardiovascular diseases. Treatment of postconfluent cell cultures with nonovertly toxic concentrations of arsenite increased DNA synthesis, similar to the mitogenic response observed with hydrogen peroxide. Within 1 hour of adding noncytotoxic concentrations of arsenite, cellular levels of oxidants increased relative to control levels, indicating that arsenite promotes cellular oxidations. Arsenite treatment increased nuclear translocation of NF-{kappa}B, an oxidative stress-responsive transcription factor, in a manner similar to that observed with hydrogen peroxide. Pretreatment of intact cells with the antioxidants N-acetylcysteine and dimethylfumarate prevented the arsenite-induced increases in cellular oxidant formation and NF-KB translocation. Arsenite had little or no effect on binding of NF-KB to its DNA recognition sequence in vitro, indicating that it is unlikely that arsenite directly affects NF-KB. The steady-state mRNA levels of intracellular adhesion molecule and urokinase-like plasminogen activator, genes associated with the active endothelial phenotype in arteriosclerosis and cancer metastasis, were increased by nontoxic concentrations of arsenite. These data suggest that arsenite promotes proliferative diseases like heart disease and cancer by activating oxidant-sensitive endothelial cell signaling and gene expression. It is possible that antioxidant therapy would be useful in preventing arsenic-induced cardiovascular disease and cancer.

  5. Effects of plant arsenic uptake and heavy metals on arsenic distribution in an arsenic-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Fayiga, Abioye O. [Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290 (United States); Ma, Lena Q. [Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290 (United States) and Key Laboratory of Terrestrial Ecological Process, Chinese Academy of Sciences, Shenyang 110016 (China)]. E-mail: lqma@ifas.ufl.edu; Zhou Qixing [Key Laboratory of Terrestrial Ecological Process, Chinese Academy of Sciences, Shenyang 110016 (China)

    2007-06-15

    This study examined the effects of heavy metals and plant arsenic uptake on soil arsenic distribution. Chemical fractionation of an arsenic-contaminated soil spiked with 50 or 200 mg kg{sup -1} Ni, Zn, Cd or Pb was performed before and after growing the arsenic hyperaccumulator Pteris vittata L for 8 weeks using NH{sub 4}Cl (water-soluble plus exchangeable, WE-As), NH{sub 4}F (Al-As), NaOH (Fe-As), and H{sub 2}SO{sub 4} (Ca-As). Arsenic in the soil was present primarily as the recalcitrant forms with Ca-As being the dominant fraction (45%). Arsenic taken up by P. vittata was from all fractions though Ca-As contributed the most (51-71% reduction). After 8 weeks of plant growth, the Al-As and Fe-As fractions were significantly (p < 0.01) greater in the metal-spiked soils than the control, with changes in the WE-As fraction being significantly (p = 0.007) correlated with plant arsenic removal. The plant's ability to solubilize soil arsenic from recalcitrant fractions may have enhanced its ability to hyperaccumulate arsenic. - Arsenic taken up by P. vittata was from all fractions with most from the Ca-fraction.

  6. Plasma-aminothiols status and inverse correlation of total homocysteine with B-vitamins in arsenic exposed population of West Bengal, India.

    Science.gov (United States)

    Mukherjee, Ashit K; Manna, Sujoy K; Roy, Sanjit K; Chakraborty, Manisha; Das, Surajit; Naskar, Jnan P

    2016-09-18

    Chronic arsenic toxicity is a serious environmental health problem across the world. Bangladesh and India (particularly the state of West Bengal) are the worst affected countries with such problem. The present study reports plasma-aminothiols (p-aminothiols) like L-cysteine (L-Cys), cysteinyl glycine (Cys-gly), total homocysteine (t-Hcy) and glutathione (GSH) status, and the inverse relationship of t-Hcy with B-vitamins (B1, B6, B9 and B12) in arsenic exposed population of West Bengal, India. Reverse phase HPLC was used to measure p-aminothiols and serum B-vitamins in different arsenic exposed population. Arsenic in drinking water and urine were measured by flow injection analysis system - Atomic Absorption Spectrometry (FIAS-AAS) and Transversely heated graphite atomizer (THGA-AAS) techniques, respectively. Water arsenic exposure was >50 µg/L in 50% population, of which majority (33.58%) belong to the range of >50-500 µg/L and more than 8% were even >1000 µg/L. Urine arsenic (µg/g creatinine) levels increased with arsenic exposure. The variability among p-aminothiols was also observed with higher exposure to arsenic in drinking water. A significant difference between exposed and control population was noticed for plasma L-Cys. The difference of B-vitamins between the population exposed to 50 µg/L arsenic in drinking water was also found to be significant. B9 and B12 deficiency with increased consumption of arsenic in water corroborates the anemic conditions commonly observed among arsenic exposed population. The aminothiol status indicated oxidative stress in exposed population. This study demonstrated progressive increase in plasma t-Hcy as well as inverse relationships of serum B-vitamins with increased water arsenic concentration. PMID:27336853

  7. Urinary Arsenic Metabolites of Subjects Exposed to Elevated Arsenic Present in Coal in Shaanxi Province, China

    Directory of Open Access Journals (Sweden)

    Linsheng Yang

    2011-06-01

    Full Text Available In contrast to arsenic (As poisoning caused by naturally occurring inorganic arsenic-contaminated water consumption, coal arsenic poisoning (CAP induced by elevated arsenic exposure from coal combustion has rarely been reported. In this study, the concentrations and distributions of urinary arsenic metabolites in 57 volunteers (36 subjects with skin lesions and 21 subjects without skin lesions, who had been exposed to elevated levels of arsenic present in coal in Changshapu village in the south of Shaanxi Province (China, were reported. The urinary arsenic species, including inorganic arsenic (iAs [arsenite (iAsIII and arsenate (iAsV], monomethylarsonic acid (MMAV and dimethylarsinic acid (DMAV, were determined by high-performance liquid chromatography (HPLC combined with inductively coupled plasma mass spectroscopy (ICP-MS. The relative distributions of arsenic species, the primary methylation index (PMI = MMAV/iAs and the secondary methylation index (SMI = DMAV/MMAV were calculated to assess the metabolism of arsenic. Subjects with skin lesions had a higher concentration of urinary arsenic and a lower arsenic methylation capability than subjects without skin lesions. Women had a significantly higher methylation capability of arsenic than men, as defined by a higher percent DMAV and SMI in urine among women, which was the one possible interpretation of women with a higher concentration of urinary arsenic but lower susceptibility to skin lesions. The findings suggested that not only the dose of arsenic exposure but also the arsenic methylation capability have an impact on the individual susceptibility to skin lesions induced by coal arsenic exposure.

  8. Bimetallic nanoparticles for arsenic detection.

    Science.gov (United States)

    Moghimi, Nafiseh; Mohapatra, Mamata; Leung, Kam Tong

    2015-06-01

    Effective and sensitive monitoring of heavy metal ions, particularly arsenic, in drinking water is very important to risk management of public health. Arsenic is one of the most serious natural pollutants in soil and water in more than 70 countries in the world. The need for very sensitive sensors to detect ultralow amounts of arsenic has attracted great research interest. Here, bimetallic FePt, FeAu, FePd, and AuPt nanoparticles (NPs) are electrochemically deposited on the Si(100) substrate, and their electrochemical properties are studied for As(III) detection. We show that trace amounts of As(III) in neutral pH could be determined by using anodic stripping voltammetry. The synergistic effect of alloying with Fe leads to better performance for Fe-noble metal NPs (Au, Pt, and Pd) than pristine noble metal NPs (without Fe alloying). Limit of detection and linear range are obtained for FePt, FeAu, and FePd NPs. The best performance is found for FePt NPs with a limit of detection of 0.8 ppb and a sensitivity of 0.42 μA ppb(-1). The selectivity of the sensor has also been tested in the presence of a large amount of Cu(II), as the most detrimental interferer ion for As detection. The bimetallic NPs therefore promise to be an effective, high-performance electrochemical sensor for the detection of ultratrace quantities of arsenic. PMID:25938763

  9. 煤中砷的测定方法及其赋存形态的研究进展%Recent Status on Methods of Determination of Arsenic in Coal and Researches of Endowed Species of Arsenic in Coal

    Institute of Scientific and Technical Information of China (English)

    凤海元; 吴晶

    2012-01-01

    A review of the recent status of methods of determination of total arsenic in coal and researches on endowed species of arsenic in coal, covering mainly the years of last decade was presented, relating especially the topics on the pretreatment of coal samples in the determination of total arsenic, various methods used in the determination of arsenic in coal and researches on the endowed species of arsenic in coal, as well as the extraction of various species of arsenic individually from the coal sample. A forecast on the future progress of the related problems mentioned above, especially on the speciation analysis for arsenic in coal was also given (35 ref. cited).%对近10年中国内外煤中砷量的测定方法以及煤中砷的赋存形态方面的研究进展作了综述。内容涉及测定煤中砷时试样的前处理方法,砷的各种测定方法和煤中砷的赋存形态研究以及各种形态砷的提取方法。对上述有关问题的发展前景也提出了期望(引述文献35篇)。

  10. 蜈蚣草砷超富集机制及其在砷污染修复中的应用%Advance of the Mechanisms of Arsenic Hyperaccumulation in Pteris vittata L. and Applications for Arsenic-Remediation

    Institute of Scientific and Technical Information of China (English)

    申红玲; 何振艳; 麻密

    2014-01-01

    The fern Pteris vittata can absorb arsenic from the soil, and most of arsenic is transported to the abo-veground tissues, stored in the vacuole of fronds. P. vittata has an efifcient antioxidant system which can reduce arsenic poisoning. Importantly, the arsenate reduction system and vacuole sequestration are critical for arsenic detoxiifcation and arsenic hyperaccumulation. In this review, the latest research progress about the physiologi-cal and molecular mechanisms of arsenic tolerance and accumulation in P. vittata was summarized, and the fu-ture applications of this fern for remediation of removal arsenic-contaminated soils or water were discussed as well.%蕨类植物蜈蚣草能够从土壤中吸收砷,并储存于地上部分羽叶的液泡中。蜈蚣草具有高效的抗氧化系统,以降低砷的毒害;其砷酸还原系统和液泡区隔化是蜈蚣草进行砷解毒和砷超富集的重要机制。本文综述了目前蜈蚣草砷超富集机制研究的主要进展,并对其在修复砷污染环境的应用中进行了讨论。

  11. Determination of arsenic compounds in earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Geiszinger, A.; Goessler, W.; Kuehnelt, D.; Kosmus, W. [Karl-Franzens-Univ., Graz (Austria). Inst. for Analytical Chemistry; Francesconi, K. [Odense Univ. (Denmark). Inst. of Biology

    1998-08-01

    Earthworms and soil collected from six sites in Styria, Austria, were investigated for total arsenic concentrations by ICP-MS and for arsenic compounds by HPLC-ICP-MS. Total arsenic concentrations ranged from 3.2 to 17.9 mg/kg dry weight in the worms and from 5.0 to 79.7 mg/kg dry weight in the soil samples. There was no strict correlation between the total arsenic concentrations in the worms and soil. Arsenic compounds were extracted from soil and a freeze-dried earthworm sample with a methanol/water mixture (9:1, v/v). The extracts were evaporated to dryness, redissolved in water, and chromatographed on an anion- and a cation-exchange column. Arsenic compounds were identified by comparison of the retention times with known standards. Only traces of arsenic acid could be extracted from the soil with the methanol/water (9:1, v/v) mixture. The major arsenic compounds detected in the extracts of the earthworms were arsenous acid and arsenic acid. Arsenobetaine was present as a minor constituent, and traces of dimethylarsinic acid were also detected. Two dimethylarsinoyltribosides were also identified in the extracts by co-chromatography with standard compounds. This is the first report of the presence of dimethylarsinoylribosides in a terrestrial organism. Two other minor arsenic species were present in the extract, but their retention times did not match with the retention times of the available standards.

  12. Variability in human metabolism of arsenic

    International Nuclear Information System (INIS)

    Estimating the nature and extent of human cancer risks due to arsenic (As) in drinking water is currently of great concern, since millions of persons worldwide are exposed to arsenic, primarily through natural enrichment of drinking water drawn from deep wells. Humans metabolize and eliminate As through oxidative methylation and subsequent urinary excretion. While there is debate as to the role of methylation in activation/detoxification, variations in arsenic metabolism may affect individual risks of toxicity and carcinogenesis. Using data from three populations, from Mexico, China, and Chile, we have analyzed the distribution in urine of total arsenic and arsenic species (inorganic arsenic (InAs), monomethyl arsenic (MMA), and dimethyl arsenic (DMA). Data were analyzed in terms of the concentration of each species and by evaluating MMA:DMA and (MMA+DMA):InAs ratios. In all persons most urinary As was present as DMA. Male:female differences were discernible in both high- and low-exposure groups from all three populations, but the gender differences varied by populations. The data also indicated bimodal distributions in the ratios of DMA to InAs and to MMA. While the gene or genes responsible for arsenic methylation are still unknown, the results of our studies among the ethnic groups in this study are consistent with the presence of functional genetic polymorphisms in arsenic methylation leading to measurable differences in toxicity. This analysis highlights the need for continuing research on the health effects of As in humans using molecular epidemiologic methods

  13. Arsenic chemistry in soils and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Fendorf, S.; Nico, P.; Kocar, B.D.; Masue, Y.; Tufano, K.J.

    2009-10-15

    Arsenic is a naturally occurring trace element that poses a threat to human and ecosystem health, particularly when incorporated into food or water supplies. The greatest risk imposed by arsenic to human health results from contamination of drinking water, for which the World Health Organization recommends a maximum limit of 10 {micro}g L{sup -1}. Continued ingestion of drinking water having hazardous levels of arsenic can lead to arsenicosis and cancers of the bladder, skin, lungs and kidneys. Unfortunately, arsenic tainted drinking waters are a global threat and presently having a devastating impact on human health within Asia. Nearly 100 million people, for example, are presently consuming drinking water having arsenic concentrations exceeding the World Health Organization's recommended limit (Ahmed et al., 2006). Arsenic contamination of the environment often results from human activities such as mining or pesticide application, but recently natural sources of arsenic have demonstrated a devastating impact on water quality. Arsenic becomes problematic from a health perspective principally when it partitions into the aqueous rather than the solid phase. Dissolved concentrations, and the resulting mobility, of arsenic within soils and sediments are the combined result of biogeochemical processes linked to hydrologic factors. Processes favoring the partitioning of As into the aqueous phase, potentially leading to hazardous concentrations, vary extensively but can broadly be grouped into four categories: (1) ion displacement, (2) desorption (or limited sorption) at pH values > 8.5, (3) reduction of arsenate to arsenite, and (4) mineral dissolution, particularly reductive dissolution of Fe and Mn (hydr)oxides. Although various processes may liberate arsenic from solids, a transition from aerobic to anaerobic conditions, and commensurate arsenic and iron/manganese reduction, appears to be a dominant, but not exclusive, means by which high concentrations of

  14. The molecular mechanism of arsenic carcinogenesis

    International Nuclear Information System (INIS)

    Arsenic compounds are known human carcinogens. Although many carcinogens are also mutagens, arsenite is not mutagenic in the V79 (hprt and Na+/K+ ATPase) system or in the G12 (qpt) system. This clearly indicates that arsenite per se does not cause any type of mutation detectable at these loci, including point mutations, small deletions and multilocus deletions. The lack of arsenic mutagenesis has led to studies emphasizing its comutagenicity. In this study, arsenite was found to enhance both UV- and MNU-mutagenesis in V79 or G12 cells. Although arsenite is comutagenic with both UV254 and UV360, the latter seems more important because of its natural relevance. The ability of arsenite to inhibit the repair of MNU-induced DNA damage was measured by a nick translation assay which measures DNA strand breaks by incorporating radioactive dNMP at their 3'OH ends in permeabilized V79 cells. It was found that strand breaks resulting from MNU or its repair accumulate in the presence of arsenite. MNU-induced poly(ADP-ribose) synthesis, measured by the incorporation of [3H]NAD+ in permeabilized cells, was also increased by post-treatment of the cells with arsenite. This supports the hypothesis that arsenite inhibits the completion of DNA repair. The accumulated strand breaks in the presence of arsenite are probably not due to direct inhibition of DNA polymerase α, the presumed repair enzyme, since very high concentrations of arsenite are needed. DNA polymerase β and DNA ligase are probably not the direct targets of arsenite for a similar reason. Thus arsenite probably inhibits the completion of DNA repair in an indirect way. Arsenite per se can inhibit metabolic cooperation and it can induce SV40 gene amplification. This suggests arsenite might also function as a tumor-promoter

  15. Breast-feeding Protects against Arsenic Exposure in Bangladeshi Infants

    OpenAIRE

    Fängström, Britta; Moore, Sophie; Nermell, Barbro; Kuenstl, Linda; Goessler, Walter; Grandér, Margaretha; Kabir, Iqbal; Palm, Brita; Arifeen, Shams El; Vahter, Marie

    2008-01-01

    Background Chronic arsenic exposure causes a wide range of health effects, but little is known about critical windows of exposure. Arsenic readily crosses the placenta, but the few available data on postnatal exposure to arsenic via breast milk are not conclusive. Aim Our goal was to assess the arsenic exposure through breast milk in Bangladeshi infants, living in an area with high prevalence of arsenic-rich tube-well water. Methods We analyzed metabolites of inorganic arsenic in breast milk ...

  16. Factors Affecting Arsenic Methylation in Arsenic-Exposed Humans: A Systematic Review and Meta-Analysis

    OpenAIRE

    Shen, Hui; Niu, Qiang; Xu, Mengchuan; Rui, Dongsheng; Xu, Shangzhi; Feng, Gangling; Ding, Yusong; Li, Shugang; Jing, Mingxia

    2016-01-01

    Chronic arsenic exposure is a critical public health issue in many countries. The metabolism of arsenic in vivo is complicated because it can be influenced by many factors. In the present meta-analysis, two researchers independently searched electronic databases, including the Cochrane Library, PubMed, Springer, Embase, and China National Knowledge Infrastructure, to analyze factors influencing arsenic methylation. The concentrations of the following arsenic metabolites increase (p< 0.000001)...

  17. Approaches to Increase Arsenic Awareness in Bangladesh: An Evaluation of an Arsenic Education Program

    OpenAIRE

    George, Christine Marie; Factor-Litvak, Pam; Khan, Khalid; ISLAM, Tariqul; Singha, Ashit; Moon-Howard, Joyce; van Geen, Alexander; Graziano, Joseph H.

    2012-01-01

    The objective of this study was to design and evaluate a household-level arsenic education and well water arsenic testing intervention to increase arsenic awareness in Bangladesh. The authors randomly selected 1,000 study respondents located in 20 villages in Singair, Bangladesh. The main outcome was the change in knowledge of arsenic from baseline to follow-up 4 to 6 months after the household received the intervention. This was assessed through a pre- and postintervention quiz concerning kn...

  18. Tumor Progression Locus 2 Promotes Induction of IFNλ, Interferon Stimulated Genes and Antigen-Specific CD8+ T Cell Responses and Protects against Influenza Virus.

    Directory of Open Access Journals (Sweden)

    Teneema Kuriakose

    2015-08-01

    Full Text Available Mitogen-activated protein kinase (MAP cascades are important in antiviral immunity through their regulation of interferon (IFN production as well as virus replication. Although the serine-threonine MAP kinase tumor progression locus 2 (Tpl2/MAP3K8 has been implicated as a key regulator of Type I (IFNα/β and Type II (IFNγ IFNs, remarkably little is known about how Tpl2 might contribute to host defense against viruses. Herein, we investigated the role of Tpl2 in antiviral immune responses against influenza virus. We demonstrate that Tpl2 is an integral component of multiple virus sensing pathways, differentially regulating the induction of IFNα/β and IFNλ in a cell-type specific manner. Although Tpl2 is important in the regulation of both IFNα/β and IFNλ, only IFNλ required Tpl2 for its induction during influenza virus infection both in vitro and in vivo. Further studies revealed an unanticipated function for Tpl2 in transducing Type I IFN signals and promoting expression of interferon-stimulated genes (ISGs. Importantly, Tpl2 signaling in nonhematopoietic cells is necessary to limit early virus replication. In addition to early innate alterations, impaired expansion of virus-specific CD8+ T cells accompanied delayed viral clearance in Tpl2-/- mice at late time points. Consistent with its critical role in facilitating both innate and adaptive antiviral responses, Tpl2 is required for restricting morbidity and mortality associated with influenza virus infection. Collectively, these findings establish an essential role for Tpl2 in antiviral host defense mechanisms.

  19. Effect of water hyacinth root extract on arsenic level in different organs of arsenic-treated rat

    OpenAIRE

    Shaheen Lipika Quayum

    2007-01-01

    The present study investigated whether the administration of the ethanol extract of water hyacinth (Eichhornia crassipes) ameliorates arsenic from arsenic-treated rats. To induce arsenic accumulation in different organs, arsenic trioxide was administered orally by gavage at a dose of 500 µg/rat/day for 7 days. In search of an effective therapeutic agent to counteract arsenic accumulation and arsenic-induced oxidative stress, different concentrations of ethanol extract of root of water hyacint...

  20. CD44v6 expression in human skin keratinocytes as a possible mechanism for carcinogenesis associated with chronic arsenic exposure

    Directory of Open Access Journals (Sweden)

    S. Huang

    2013-01-01

    Full Text Available Inorganic arsenic is a well-known human skin carcinogen. Chronic arsenic exposure results in various types of human skin lesions, including squamous cell carcinoma (SCC. To investigate whether mutant stem cells participate in arsenic-associated carcinogenesis, we repeatedly exposed the HaCaT cells line to an environmentally relevant level of arsenic (0.05 ppm in vitro for 18 weeks. Following sodium arsenic arsenite administration, cell cycle, colony-forming efficiency (CFE, cell tumorigenicity, and expression of CD44v6, NF-κB and p53, were analyzed at different time points (0, 5, 10, 15, 20, 25 and 30 passages. We found that a chronic exposure of HaCaT cells to a low level of arsenic induced a cancer stem- like phenotype. Furthermore, arsenic-treated HaCaT cells also became tumorigenic in nude mice, their growth cycle was predominantly in G2/M and S phases. Relative to nontreated cells, they exhibited a higher growth rate and a significant increase in CFE. Western blot analysis found that arsenic was capable of increasing cell proliferation and sprouting of cancer stem-like phenotype. Additionally, immunohistochemical analysis demonstrated that CD44v6 expression was up-regulated in HaCaT cells exposed to a low level of arsenic during early stages of induction. The expression of CD44v6 in arsenic-treated cells was positively correlated with their cloning efficiency in soft agar (r=0.949, P=0.01. Likewise, the expressions of activating transcription factor NF-κB and p53 genes in the arsenic-treated HaCaT cells were significantly higher than that in non-treated cells. Higher expressions of CD44v6, NF-κB and p53 were also observed in tumor tissues isolated from Balb/c nude mice. The present results suggest that CD44v6 may be a biomarker of arsenic-induced neoplastic transformation in human skin cells, and that arsenic promotes malignant transformation in human skin lesions through a NF-κB signaling pathway-stimulated expression of CD44v6.

  1. Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.

    Science.gov (United States)

    Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott

    2015-07-01

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration. PMID:26057865

  2. Progress report on the promotion and use of renewable energy sources. 1. report. Implementation of article 22 of European Union Directive 2009/28/EEC

    International Nuclear Information System (INIS)

    This report has been prepared for the European Commission pursuant to article 22 of Directive 2009/28/EEC regarding the promotion and use of energy produced from renewable sources, based on the model provided by the Commission. Contents: 1. Sectoral and overall shares, actual production and consumption of energy from renewable sources for 2009 and 2010; 2. Measures taken during the last 2 years and/or forecast at a national level for promoting renewable energy sources; 2.a Evaluations and improvements for administrative procedures aimed at removing regulatory and other obstacles to the development of renewable energy sources; 2.b Measures aimed at ensuring the transmission and distribution of renewable electricity and improving the regulatory framework concerning the management and sharing of grid connection and consolidation costs; 3. Description of support schemes and promotional measures for renewable energy sources and new elements introduced by the national action plan; 3.1. Information on the mode of distribution between end-users of electricity benefiting from support in accordance with article 3, paragraph 6 of Directive 2003/54/EEC; 4. Information on the manner in which support schemes are structured, where appropriate, for integrating RES applications presenting additional advantages but which can entail higher costs, notably biofuels produced from waste, residue, non-food cellulose material and lignocellulose material; 5. Information on the guarantees of origin mechanism for electricity, heating and cooling from RES, and measures taken to ensure the system's reliability and protection against fraud; 6. Description of changes brought over the 2 previous years on the availability and use of biomass resources for energy purposes; 7. Changes to the prices of basic products and land use for the past 2 years in relation to the increased use of biomass and other forms of renewable energy; 8. Evolution in the share of biofuels produced from waste, residue

  3. FXR促进肝脏再生作用的研究进展%Progress in understanding the role of FXR in promoting liver regeneration

    Institute of Scientific and Technical Information of China (English)

    于昊; 崔云甫

    2012-01-01

    The regenerative capacity of the liver is well known, and it can regenerate itself by a compensatory regrowth in response to partial hepa-tectomy or injury. Farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors. Bile acids are FXR physiological ligands. As a metabolic regulator, FXR plays key roles in regulating metabolism of bile acids, lipids and glucose. Recently, activation of intercellular signal transduction has been shown to play an important role in liver regeneration by binding of bile acids to their receptor FXR. Bile acid/FXR signaling pathway is required for normal liver regeneration. Furthermore, FXR promotes liver repair after injury, and activation of FXR is able to alleviate age-related defective liver regeneration. These novel findings suggest that FXR-mediated bile acid signaling is an important component of normal liver regeneration and highlight the potential use of FXR ligands to promote liver regeneration after segmental liver transplantation or resection of liver tumors. This review summarizes the recent progress in understanding the role of FXR in promoting liver regeneration.%肝脏具有再生的能力是众所周知的,他在部分切除或损伤后通过代偿增生的方式能够实现自我再生.法尼酯X受体(farnesoid X receptor,FXR)是配体激活转录因子的核激素受体超家族中的一员,胆汁酸是FXR的内源性配体.作为一种代谢调节因子,FXR在调节胆汁酸、脂质和葡萄糖的代谢中起到了至关重要的作用.近来,研究发现胆汁酸与其受体FXR结合激活细胞间的信号转导对肝再生起重要作用,胆汁酸/FXR信号通路是正常肝再生所必需的.此外,FXR能促进肝脏损伤后的修复,且FXR的活化能够减轻年龄相关性的肝脏再生缺陷.这些新的发现提示FXR介导的胆汁酸信号在正常肝再生中是一个不可或缺的组成部分,同时也突出了FXR配体对促进部分

  4. Current developments in toxicological research on arsenic

    OpenAIRE

    Bolt, Hermann M.

    2013-01-01

    There is a plethora of recent publications on all aspects relevant to the toxicology of arsenic (As). Over centuries exposures to arsenic continue to be a major public health problem in many countries. In particular, the occurrence of high As concentrations in groundwater of Southeast Asia receives now much attention. Therefore, arsenic is a high-priority matter for toxicological research. Key exposure to As are (traditional) medicines, combustion of As-rich coal, presence of As in groundwate...

  5. Dissolved Air Flotation of arsenic adsorbent particles

    OpenAIRE

    Santander, M.; Valderrama, L.

    2015-01-01

    The removal of arsenic from synthetic effluent was studied using the adsorbent particle flotation technique (APF) and dissolved air flotation (DAF). A sample of an iron mineral was used as adsorbent particles of arsenic, ferric chloride as coagulant, cationic polyacrylamide (NALCO 9808) as flocculants, and sodium oleate as collector. Adsorption studies to determine the pH influence, contact time, and adsorbent particles concentration on the adsorption of arsenic were carried out along with fl...

  6. Arsenic Toxicity in Male Reproduction and Development

    OpenAIRE

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-01-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic a...

  7. Interaction of Arsenic with Zinc and Organics in a Rice (Oryza sativa L.)–Cultivated Field in India

    OpenAIRE

    Dilip Kumar Das; T. K. Garai; Sarkar, S; Pintu Sur

    2005-01-01

    A laboratory experiment on an Inceptisol with pH 7.6, organic carbon 6.8 g kg–1, and 0.5 M NaHCO3 extractable arsenic 0.4 mg kg–1 was conducted to study the interaction effect of graded levels of arsenic (0, 5, and 10 mg kg–1) with zinc (0, 10, and 20 mg kg–1) and organics (0, 1, and 2% on soil weight basis) separately on the mobilization of arsenic in soils.The results show that the amount of 0.5 M NaHCO3 extractable arsenic at pH 8.5 increased with the progress of submergence up to 35 days....

  8. Acute arsenic poisoning in two siblings.

    Science.gov (United States)

    Lai, Melisa W; Boyer, Edward W; Kleinman, Monica E; Rodig, Nancy M; Ewald, Michele Burns

    2005-07-01

    We report a case series of acute arsenic poisoning of 2 siblings, a 4-month-old male infant and his 2-year-old sister. Each child ingested solubilized inorganic arsenic from an outdated pesticide that was misidentified as spring water. The 4-month-old child ingested a dose of arsenic that was lethal despite extraordinary attempts at arsenic removal, including chelation therapy, extracorporeal membrane oxygenation, exchange transfusion, and hemodialysis. The 2-year-old fared well with conventional therapy. PMID:15995066

  9. XAS Studies of Arsenic in the Environment

    International Nuclear Information System (INIS)

    Arsenic is present in low concentrations in much of the Earth's crust and changes in its speciation are vital to understanding its transport and toxicity in the environment. We have used X-ray absorption spectroscopy to investigate the coordination sites of arsenic in a wide variety of samples, including soil and earthworm tissues from arsenic-contaminated land, and human hair and nail samples from people exposed to arsenic in Cambodia. Our results confirm the effectiveness of using X-ray absorption near edge structure (XANES) and X-ray absorption fine structure (EXAFS) spectroscopy to determine speciation changes in environmental samples

  10. Arsenic in the soils of Zimapan, Mexico

    International Nuclear Information System (INIS)

    Arsenic concentrations of 73 soil samples collected in the semi-arid Zimapan Valley range from 4 to 14 700 mg As kg-1. Soil arsenic concentrations decrease with distance from mines and tailings and slag heaps and exceed 400 mg kg-1 only within 500 m of these arsenic sources. Soil arsenic concentrations correlate positively with Cu, Pb, and Zn concentrations, suggesting a strong association with ore minerals known to exist in the region. Some As was associated with Fe and Mn oxyhydroxides, this association is less for contaminated than for uncontaminated samples. Very little As was found in the mobile water-soluble or exchangeable fractions. The soils are not arsenic contaminated at depths greater than 100 cm below the surface. Although much of the arsenic in the soils is associated with relatively immobile solid phases, this represents a long-term source of arsenic to the environment. -- Much of the arsenic is relatively immobile but presents long-term source of arsenic

  11. Polymorphisms in cell cycle regulatory genes, urinary arsenic profile and urothelial carcinoma

    International Nuclear Information System (INIS)

    Introduction: Polymorphisms in p53, p21 and CCND1 could regulate the progression of the cell cycle and might increase the susceptibility to inorganic arsenic-related cancer risk. The goal of our study was to evaluate the roles of cell cycle regulatory gene polymorphisms in the carcinogenesis of arsenic-related urothelial carcinoma (UC). Methods: A hospital-based case-controlled study was conducted to explore the relationships among the urinary arsenic profile, 8-hydroxydeoxyguanosine (8-OHdG) levels, p53 codon 72, p21 codon 31 and CCND1 G870A polymorphisms and UC risk. The urinary arsenic profile was determined using high-performance liquid chromatography (HPLC) and hydride generator-atomic absorption spectrometry (HG-AAS). 8-OHdG levels were measured by high-sensitivity enzyme-linked immunosorbent assay (ELISA) kits. Genotyping was conducted using polymerase chain reaction-restriction fragment length polymerase (PCR-RFLP). Results: Subjects carrying the p21 Arg/Arg genotype had an increased UC risk (age and gender adjusted OR = 1.53; 95% CI, 1.02-2.29). However, there was no association of p53 or CCND1 polymorphisms with UC risk. Significant effects were observed in terms of a combination of the three gene polymorphisms and a cumulative exposure of cigarette smoking, along with the urinary arsenic profile on the UC risk. The higher total arsenic concentration, monomethylarsonic acid percentage (MMA%) and lower dimethylarsinic acid percentage (DMA%), possessed greater gene variant numbers, had a higher UC risk and revealed significant dose-response relationships. However, effects of urinary 8-OHdG levels combined with three gene polymorphisms did not seem to be important for UC risk. Conclusions: The results showed that the variant genotype of p21 might be a predictor of inorganic arsenic-related UC risk

  12. Infrared spectrum of arsenic pentafluoride

    International Nuclear Information System (INIS)

    After a literature review about arsenic fluorides, we give several methods of obtaining very pure AsF5 in order to ascertain the right spectrum of this compound. Our spectra fit well with Akers's observations, and we note that AsF5 structure can be explained in terms of C3v molecular symmetry, with the As-F bond stretching lying at 786 cm-1 and 811 cm-1. (author)

  13. Arsenic (+3 oxidation state) methyltransferase and the inorganic arsenic methylation phenotype

    International Nuclear Information System (INIS)

    Inorganic arsenic is enzymatically methylated; hence, its ingestion results in exposure to the parent compound and various methylated arsenicals. Both experimental and epidemiological evidences suggest that some of the adverse health effects associated with chronic exposure to inorganic arsenic may be mediated by these methylated metabolites. If i As methylation is an activation process, then the phenotype for inorganic arsenic methylation may determine risk associated with exposure to this metalloid. We examined inorganic arsenic methylation phenotypes and arsenic (+3 oxidation state) methyltransferase genotypes in four species: three that methylate inorganic arsenic (human (Homo sapiens), rat (Rattus norwegicus), and mouse (Mus musculus)) and one that does not methylate inorganic arsenic (chimpanzee, Pan troglodytes). The predicted protein products from arsenic (+3 oxidation state) methyltransferase are similar in size for rat (369 amino acid residues), mouse (376 residues), and human (375 residues). By comparison, a 275-nucleotide deletion beginning at nucleotide 612 in the chimpanzee gene sequence causes a frameshift that leads to a nonsense mutation for a premature stop codon after amino acid 205. The null phenotype for inorganic arsenic methylation in the chimpanzee is likely due to the deletion in the gene for arsenic (+3 oxidation state) methyltransferase that yields an inactive truncated protein. This lineage-specific loss of function caused by the deletion event must have occurred in the Pan lineage after Homo-Pan divergence about 5 million years ago

  14. Arsenic Removal by Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Tiziana Marino

    2015-03-01

    Full Text Available Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III and As(V from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

  15. Chromosome analysis of arsenic affected cattle

    Directory of Open Access Journals (Sweden)

    S. Shekhar

    2014-10-01

    Full Text Available Aim: The aim was to study the chromosome analysis of arsenic affected cattle. Materials and Methods: 27 female cattle (21 arsenic affected and 6 normal were selected for cytogenetical study. The blood samples were collected, incubated, and cultured using appropriate media and specific methods. The samples were analyzed for chromosome number and morphology, relative length of the chromosome, arm ratio, and centromere index of X chromosome and chromosomal abnormalities in arsenic affected cattle to that of normal ones. Results: The diploid number of metaphase chromosomes in arsenic affected cattle as well as in normal cattle were all 2n=60, 58 being autosomes and 2 being sex chromosomes. From the centromeric position, karyotyping studies revealed that all the 29 pair of autosomes was found to be acrocentric or telocentric, and the sex chromosomes (XX were submetacentric in both normal and arsenic affected cattle. The relative length of all the autosome pairs and sex chrosomosome pair was found to be higher in normal than that of arsenic affected cattle. The mean arm ratio of X-chromosome was higher in normal than that of arsenic affected cattle, but it is reverse in case of centromere index value of X-chromosome. There was no significant difference of arm ratio and centromere index of X-chromosomes between arsenic affected and normal cattle. No chromosomal abnormalities were found in arsenic affected cattle. Conclusion: The chromosome analysis of arsenic affected cattle in West Bengal reported for the first time in this present study which may serve as a guideline for future studies in other species. These reference values will also help in comparison of cytological studies of arsenic affected cattle to that of various toxicants.

  16. Arsenic Adsorption Onto Iron Oxides Minerals

    Science.gov (United States)

    Aredes, S.; Klein, B.; Pawlik, M.

    2004-12-01

    The predominant form of arsenic in water is as an inorganic ion. Under different redox conditions arsenic in water is stable in the +5 and +3 oxidation states. Arsenic oxidation state governs its toxicity, chemical form and solubility in natural and disturbed environments. As (III) is found in anoxic environments such as ground water , it is toxic and the common species is the neutral form, H3AsO3. As (V) is found in aerobic conditions such as surface water, it is less toxic and the common species in water are: H2AsO4 - and HAsO4 {- 2}. The water pH determines the predominant arsenate or arsenite species, however, both forms of arsenic can be detected in natural water systems. Iron oxides minerals often form in natural waters and sediments at oxic-anoxic boundaries. Over time they undergo transformation to crystalline forms, such as goethite or hematite. Both As(V) and As(III) sorbs strongly to iron oxides, however the sorption behavior of arsenic is dependent on its oxidation state and the mineralogy of the iron oxides. Competition between arsenic and others ions, such fluoride, sulphate and phosphate also play a role. On the other hand, calcium may increase arsenic adsorption onto iron oxides. Electrokinetic studies and adsorption experiments were carried out in order to determine which conditions favour arsenic adsorption. Hematite, goethite and magnetite as iron based sorbents were used. Test were also conducted with a laterite soil rich in iron minerals. The focus of this study is to evaluate physical and chemical conditions which favour arsenic adsorption onto iron oxides minerals, the results contribute to an understanding of arsenic behaviour in natural and disturbed environments. Furthermore, results could contribute in developing an appropriate remediation technology for arsenic removal in water using iron oxides minerals.

  17. Interactions between arsenic species and marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.G.

    1978-01-01

    The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg/sup -1/, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1/sup -1/ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1/sup -1/. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB)

  18. Impaired arsenic metabolism in children during weaning

    International Nuclear Information System (INIS)

    Background: Methylation of inorganic arsenic (iAs) via one-carbon metabolism is a susceptibility factor for a range of arsenic-related health effects, but there is no data on the importance of arsenic metabolism for effects on child development. Aim: To elucidate the development of arsenic metabolism in early childhood. Methods: We measured iAs, methylarsonic acid (MA) and dimethylarsinic acid (DMA), the metabolites of iAs, in spot urine samples of 2400 children at 18 months of age. The children were born to women participating in a population-based longitudinal study of arsenic effects on pregnancy outcomes and child development, carried out in Matlab, a rural area in Bangladesh with a wide range of arsenic concentrations in drinking water. Arsenic metabolism was evaluated in relation to age, sex, anthropometry, socio-economic status and arsenic exposure. Results: Arsenic concentrations in child urine (median 34 μg/L, range 2.4-940 μg/L), adjusted to average specific gravity of 1.009 g/mL, were considerably higher than that measured at 3 months of age, but lower than that in maternal urine. Child urine contained on average 12% iAs, 9.4% MA and 78% DMA, which implies a marked change in metabolite pattern since infancy. In particular, there was a marked increase in urinary %MA, which has been associated with increased risk of health effects. Conclusion: The arsenic metabolite pattern in urine of children at 18 months of age in rural Bangladesh indicates a marked decrease in arsenic methylation efficiency during weaning.

  19. ARSENIC REMOVAL AND ECOLOGICALLY SAFE CONTAINMENT OF ARSENIC-WASTE: A SUSTAINABLE SOLUTION FOR ARSENIC CRISIS IN CAMBODIA

    Science.gov (United States)

    An appalling degree of arsenic contamination in groundwater has affected more than a million people in wide region of Mekong delta flood plain in Cambodia. Arsenic is by far the most toxic species of all naturally occurring groundwater contaminants and disposal of removed arse...

  20. Bioaccumulation of Arsenic by Fungi

    Directory of Open Access Journals (Sweden)

    Ademola O. Adeyemi

    2009-01-01

    Full Text Available Problem statement: Arsenic is a known toxic element and its presence and toxicity in nature is a worldwide environmental problem. The use of microorganisms in bioremediation is a potential method to reduce as concentration in contaminated areas. Approach: In order to explore the possible bioremediation of this element, three filamentous fungi-Aspergillus niger, Serpula himantioides and Trametes versicolor were investigated for their potential abilities to accumulate (and possibly solubilize arsenic from an agar environment consisting of non buffered mineral salts media amended with 0.2, 0.4, 0.6 and 0.8% (w/v arsenopyrite (FeAsS. Growth rates, dry weights, arsenic accumulation and oxalate production by the fungi as well as the pH of the growth media were all assessed during this study. Results: There was no visible solubilization of FeAsS particles underneath any of the growing fungal colonies or elsewhere in the respective agar plates. No specific patterns of growth changes were observed from the growth ratios of the fungi on agar amended with different amounts of FeAsS although growth of all fungi was stimulated by the incorporation of varying amounts of FeAsS into the agar with the exception of A. niger on 0.4% (w/v amended agar and T. versicolor on 0.8% (w/v amended agar. The amounts of dry weights obtained for all three fungi also did not follow any specific patterns with different amounts of FeAsS and the quantities obtained were in the order A. niger > S. himantioides > T. versicolor. All fungi accumulated as in their biomasses with all amounts of FeAsS although to varying levels and T. versicolor was the most effective with all amounts of FeAsS while A. niger was the least effective. Conclusion: The accumulation of arsenic in the biomasses of the test fungi as shown in this study may suggested a role for fungi through their bioaccumulating capabilities as agents in the possible bioremediation of arsenic contaminated environments.

  1. 29 CFR 1915.1018 - Inorganic arsenic.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Inorganic arsenic. 1915.1018 Section 1915.1018 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1018 Inorganic arsenic. Note: The requirements applicable to shipyard employment under...

  2. 29 CFR 1926.1118 - Inorganic arsenic.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Inorganic arsenic. Note: The requirements applicable to construction work under this section are...

  3. The Chemistry and Metabolism of Arsenic

    Science.gov (United States)

    I. IntrodctionA century of study of the process by which many organisms convert inorganic arsenic into an array of methylated metabolites has answered many questions and has posed some new ones. The capacity of microorganisms to. form volatile arsenic compounds was first recogniz...

  4. ARSENIC EFFECTS ON TELOMERE AND TELOMERASE ACTIVITY

    Science.gov (United States)

    Arsenic effects on telomere and telomerase activity. T-C. Zhang, M. T. Schmitt, J. Mo, J. L. Mumford, National Research Council and U.S Environmental Protection Agency, NHEERL, Research Triangle Park, NC 27711Arsenic is a known carcinogen and also an anticancer agent for acut...

  5. Arsenic and human health effects: A review.

    Science.gov (United States)

    Abdul, Khaja Shameem Mohammed; Jayasinghe, Sudheera Sammanthi; Chandana, Ediriweera P S; Jayasumana, Channa; De Silva, P Mangala C S

    2015-11-01

    Arsenic (As) is ubiquitous in nature and humans being exposed to arsenic via atmospheric air, ground water and food sources are certain. Major sources of arsenic contamination could be either through geological or via anthropogenic activities. In physiological individuals, organ system is described as group of organs that transact collectively and associate with other systems for conventional body functions. Arsenic has been associated with persuading a variety of complications in body organ systems: integumentary, nervous, respiratory, cardiovascular, hematopoietic, immune, endocrine, hepatic, renal, reproductive system and development. In this review, we outline the effects of arsenic on the human body with a main focus on assorted organ systems with respective disease conditions. Additionally, underlying mechanisms of disease development in each organ system due to arsenic have also been explored. Strikingly, arsenic has been able to induce epigenetic changes (in utero) and genetic mutations (a leading cause of cancer) in the body. Occurrence of various arsenic induced health effects involving emerging areas such as epigenetics and cancer along with their respective mechanisms are also briefly discussed. PMID:26476885

  6. Arsenic Consumption in the United States.

    Science.gov (United States)

    Wilson, Denise

    2015-10-01

    Exposure limits for arsenic in drinking water and minimal risk levels (MRLs) for total dietary exposure to arsenic have long been established in the U.S. Multiple studies conducted over the last five years have detected arsenic in foods and beverages including juice, rice, milk, broth (beef and chicken), and others. Understanding whether or not each of these foods or drinks is a concern to certain groups of individuals requires examining which types of and how much arsenic is ingested. In this article, recent studies are reviewed and placed in the context of consumption patterns. When single sources of food or drink are considered in isolation, heavy rice eaters can be exposed to the most arsenic among adults while infants consuming formula containing contaminated organic brown rice syrup are the most exposed group among children. Most food and drink do not contain sufficient arsenic to exceed MRLs. For individuals consuming more than one source of contaminated water or food, however, adverse health effects are more likely. In total, recent studies on arsenic contamination in food and beverages emphasize the need for individual consumers to understand and manage their total dietary exposure to arsenic. PMID:26591332

  7. Arsenic Uptake by Muskmelon (Cucumis melo) Plants from Contaminated Water.

    Science.gov (United States)

    Hettick, Bryan E; Cañas-Carrell, Jaclyn E; Martin, Kirt; French, Amanda D; Klein, David M

    2016-09-01

    Arsenic is a carcinogenic element that occurs naturally in the environment. High levels of arsenic are found in water in some parts of the world, including Texas. The aims of this study were to determine the distribution of arsenic in muskmelon (Cucumis melo) plants accumulated from arsenic spiked water and to observe effects on plant biomass. Plants were grown and irrigated using water spiked with variable concentrations of arsenic. Inductively coupled plasma mass spectrometry was used to quantify arsenic in different parts of the plant and fruit. Under all conditions tested in this study, the highest concentrations of arsenic were found in the leaves, soil, and roots. Arsenic in the water had no significant effect on plant biomass. Fruits analyzed in this study had arsenic concentrations of 101 μg/kg or less. Consuming these fruits would result in less arsenic exposure than drinking water at recommended levels. PMID:27460822

  8. Methylation of inorganic arsenic by murine fetal tissue explants.

    Science.gov (United States)

    Broka, Derrick; Ditzel, Eric; Quach, Stephanie; Camenisch, Todd D

    2016-07-01

    Although it is generally believed that the developing fetus is principally exposed to inorganic arsenic and the methylated metabolites from the maternal metabolism of arsenic, little is known about whether the developing embryo can autonomously metabolize arsenic. This study investigates inorganic arsenic methylation by murine embryonic organ cultures of the heart, lung, and liver. mRNA for AS3mt, the gene responsible for methylation of arsenic, was detected in all embryonic tissue types studied. In addition, methylated arsenic metabolites were generated by all three tissue types. The fetal liver explants yielded the most methylated arsenic metabolites (∼7% of total arsenic/48 h incubation) while the heart, and lung preparations produced slightly greater than 2% methylated metabolites. With all tissues the methylation proceeded mostly to the dimethylated arsenic species. This has profound implications for understanding arsenic-induced fetal toxicity, particularly if the methylated metabolites are produced autonomously by embryonic tissues. PMID:26446802

  9. Elucidating the pathway for arsenic methylation

    International Nuclear Information System (INIS)

    Although biomethylation of arsenic has been studied for more than a century, unequivocal demonstration of the methylation of inorganic arsenic by humans occurred only about 30 years ago. Because methylation of inorganic arsenic activates it to more reactive and toxic forms, elucidating the pathway for the methylation of this metalloid is a topic of considerable importance. Understanding arsenic metabolism is of public health concern as millions of people chronically consume drinking water that contains high concentrations of inorganic arsenic. Hence, the focus of our research has been to elucidate the molecular basis of the steps in the pathway that leads from inorganic arsenic to methylated and dimethylated arsenicals. Here we describe a new S-adenosylmethionine (AdoMet)-dependent methyltransferase from rat liver cytosol that catalyzes the conversion of arsenite to methylated and dimethylated species. This 42-kDa protein has sequence motifs common to many non-nucleic acid methyltransferases and is closely related to methyltransferases of previously unknown function that have been identified by conceptual translations of cyt19 genes of mouse and human genomes. Hence, we designate rat liver arsenic methyltransferase as cyt19 and suggest that orthologous cyt19 genes encode an arsenic methyltransferase in the mouse and human genomes. Our studies with recombinant rat cyt19 find that, in the presence of an exogenous or a physiological reductant, this protein can catalyze the entire sequence of reactions that convert arsenite to methylated metabolites. A scheme linking cyt19 and thioredoxin-thioredoxin reductase in the methylation and reduction of arsenicals is proposed

  10. Arsenic burden survey among refuse incinerator workers

    Directory of Open Access Journals (Sweden)

    Chao Chung-Liang

    2005-01-01

    Full Text Available Background: Incinerator workers are not considered to have arsenic overexposure although they have the risk of overexposure to other heavy metals. Aim: To examine the relationship between arsenic burden and risk of occupational exposure in employees working at a municipal refuse incinerator by determining the concentrations of arsenic in the blood and urine. Settings and Design: The workers were divided into three groups based on their probability of contact with combustion-generated residues, namely Group 1: indirect contact, Group 2: direct contact and Group 3: no contact. Healthy age- and sex-matched residents living in the vicinity were enrolled as the control group. Materials and Methods: Heavy metal concentrations were measured by atomic absorption spectrophotometer. Downstream rivers and drinking water of the residents were examined for environmental arsenic pollution. A questionnaire survey concerning the contact history of arsenic was simultaneously conducted. Statistical analysis: Non-parametric tests, cross-tabulation and multinomial logistic regression. Results: This study recruited 122 incinerator workers. The urine and blood arsenic concentrations as well as incidences of overexposure were significantly higher in the workers than in control subjects. The workers who had indirect or no contact with combustion-generated residues had significantly higher blood arsenic level. Arsenic contact history could not explain the difference. Airborne and waterborne arsenic pollution were not detected. Conclusion: Incinerator workers run the risk of being exposed to arsenic pollution, especially those who have incomplete protection in the workplace even though they only have indirect or no contact with combustion-generated pollutants.

  11. Arsenic Geochemistry in Source Waters of the Los Angeles Aqueduct

    OpenAIRE

    Hering, Janet G; Wilkie, Jennifer A; Chiu, Van Q

    1997-01-01

    Arsenic is a widely distributed constituent of geologic materials, with an average crustal abundance of 1.8 ppm. The natural processes of weathering of arsenic-containing minerals and volcanism contribute arsenic to groundwaters, surface freshwaters, and seawater. Recently, increased attention has focused on arsenic geochemistry in natural waters. This attention has been motivated by concern over the human health effects of arsenic exposure; consumption of drinking water can be a significant,...

  12. A review on environmental factors regulating arsenic methylation in humans

    International Nuclear Information System (INIS)

    Subjects exposed to arsenic show significant inter-individual variation in urinary patterns of arsenic metabolites but insignificant day-to-day intra-individual variation. The inter-individual variation in arsenic methylation can be partly responsible for the variation in susceptibility to arsenic toxicity. Wide inter-ethnic variation and family correlation in urinary arsenic profile suggest a genetic effect on arsenic metabolism. In this paper the environmental factors affecting arsenic metabolism are reviewed. Methylation capacity might reduce with increasing dosage of arsenic exposure. Furthermore, women, especially at pregnancy, have better methylation capacity than their men counterparts, probably due to the effect of estrogen. Children might have better methylation capacity than adults and age shows inconsistent relevance in adults. Smoking and alcohol consumption might be associated with a poorer methylation capacity. Nutritional status is important in the methylation capacity and folate may facilitate the methylation and excretion of arsenic. Besides, general health conditions and medications might influence the arsenic methylation capacity; and technical problems can cause biased estimates. The consumption of seafood, seaweed, rice and other food with high arsenic contents and the extent of cooking and arsenic-containing water used in food preparation may also interfere with the presentation of the urinary arsenic profile. Future studies are necessary to clarify the effects of the various arsenic metabolites including the trivalent methylated forms on the development of arsenic-induced human diseases with the consideration of the effects of confounding factors and the interactions with other effect modifiers

  13. Epigenetic mediated transcriptional activation of WNT5A participates in arsenical-associated malignant transformation

    International Nuclear Information System (INIS)

    Arsenic is a human carcinogen with exposure associated with cancer of the lung, skin, and bladder. Many potential mechanisms have been implicated as playing a role in the process of arsenical-induced malignancy including the perturbation of signaling pathways and aberrant epigenetic regulation. We initiated studies to examine the role of a member of the non-canonical WNT signaling pathway, WNT5A, in UROtsa cells and arsenite [URO-ASSC] and monomethylarsonous acid [URO-MSC] malignantly transformed variants. We present data herein that suggest that WNT5A is transcriptionally activated during arsenical-induced malignant transformation. This WNT5A transcriptional activation is correlated with the enrichment of permissive histone modifications and the reduction of repressive modifications in the WNT5A promoter region. The epigenetic activation of WNT5A expression and acetylation of its promoter remain after the removal of the arsenical, consistent with the maintenance of an anchorage independent growth phenotype in these cells. Additionally, treatment with epigenetic modifying drugs supports a functional role for these epigenetic marks in controlling gene expression. Reduction of WNT5A using lentiviral shRNA greatly attenuated the ability of these cells to grow in an anchorage independent fashion. Extension of our model into human bladder cancer cell lines indicates that each of the cell lines examined also express WNT5A. Taken together, these data suggest that the epigenetic remodeling of the WNT5A promoter is correlated with its transcriptional activation and this upregulation likely participates in arsenical-induced malignant transformation

  14. Arsenic Metabolites, Including N-Acetyl-4-hydroxy-m-arsanilic Acid, in Chicken Litter from a Roxarsone-Feeding Study Involving 1600 Chickens.

    Science.gov (United States)

    Yang, Zonglin; Peng, Hanyong; Lu, Xiufen; Liu, Qingqing; Huang, Rongfu; Hu, Bin; Kachanoski, Gary; Zuidhof, Martin J; Le, X Chris

    2016-07-01

    The poultry industry has used organoarsenicals, such as 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, ROX), to prevent disease and to promote growth. Although previous studies have analyzed arsenic species in chicken litter after composting or after application to agricultural lands, it is not clear what arsenic species were excreted by chickens before biotransformation of arsenic species during composting. We describe here the identification and quantitation of arsenic species in chicken litter repeatedly collected on days 14, 24, 28, 30, and 35 of a Roxarsone-feeding study involving 1600 chickens of two strains. High performance liquid chromatography separation with simultaneous detection by both inductively coupled plasma mass spectrometry and electrospray ionization tandem mass spectrometry provided complementary information necessary for the identification and quantitation of arsenic species. A new metabolite, N-acetyl-4-hydroxy-m-arsanilic acid (N-AHAA), was identified, and it accounted for 3-12% of total arsenic. Speciation analyses of litter samples collected from ROX-fed chickens on days 14, 24, 28, 30, and 35 showed the presence of N-AHAA, 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA), inorganic arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA(V)), dimethylarsinic acid (DMA(V)), and ROX. 3-AHPAA accounted for 3-19% of the total arsenic. Inorganic arsenicals (the sum of As(III) and As(V)) comprised 2-6% (mean 3.5%) of total arsenic. Our results on the detection of inorganic arsenicals, methylarsenicals, 3-AHPAA, and N-AHAA in the chicken litter support recent findings that ROX is actually metabolized by the chicken or its gut microbiome. The presence of the toxic metabolites in chicken litter is environmentally relevant as chicken litter is commonly used as fertilizer. PMID:26876684

  15. A broad view of arsenic.

    Science.gov (United States)

    Jones, F T

    2007-01-01

    In the mind of the general public, the words "arsenic" and "poison" have become almost synonymous. Yet, As is a natural metallic element found in low concentrations in virtually every part of the environment, including foods. Mining and smelting activities are closely associated with As, and the largest occurrence of As contamination in the United States is near the gold mines of northern Nevada. Inhabitants of Bangladesh and surrounding areas have been exposed to water that is naturally and heavily contaminated with As, causing what the World Health Organization has described as the worst mass poisoning in history. Although readily absorbed by humans, most inorganic As (>90%) is rapidly cleared from the blood with a half-life of 1 to 2 h, and 40 to 70% of the As intake is absorbed, metabolized, and excreted within 48 h. Arsenic does not appreciably bioaccumulate, nor does it biomagnify in the food chain. The United States has for some time purchased more As than any other country in the world, but As usage is waning, and further reductions appear likely. Arsenic is used in a wide variety of industrial applications, from computers to fireworks. All feed additives used in US poultry feeds must meet the strict requirements of the US Food and Drug Administration Center for Veterinary Medicine (Rockville, MD) before use. Although some public health investigators have identified poultry products as a potentially significant source of total As exposure for Americans, studies consistently demonstrate that <1% of samples tested are above the 0.5 ppm limit established by the US Food and Drug Administration Center for Veterinary Medicine. Although laboratory studies have demonstrated the possibility that As in poultry litter could pollute ground waters, million of tons of litter have been applied to the land, and no link has been established between litter application and As contamination of ground water. Yet, the fact that <2% of the United States population is involved in

  16. A greenhouse study on arsenic remediation potential of Vetiver grass (Vetiveria Zizanioides) as a function of soil physico-chemical properties

    Science.gov (United States)

    Quispe, M. A.; Datta, R.; Sarkar, D.; Sharma, S.

    2006-05-01

    Arsenic is one of the most harmful and toxic metals, being a Group A human carcinogen. Mining activities as well as the use of arsenic-containing pesticides have resulted in the contamination of a wide variety of sites including mine tailings, cattle dip sites, wood treatment sites, pesticide treatment areas, golf courses, etc. Phytoremediation has emerged as a novel and promising technology, which uses plants to clean up contaminated soil and water taking advantage of plant's natural abilities to extract and accumulate various contaminants. This method has distinct advantages, since it maintains the biological properties and physical structure of the soil, is environment friendly, and above all, inexpensive. However, effective remediation of contaminated residential soils using a specific plant species is an immensely complex task whose success depends on a multitude of factors including the ability of the target plant to uptake, translocate, detoxify, and accumulate arsenic in its system. One of the major challenges in phytoremediation lies in identifying a fast- growing, high biomass plant that can accumulate the contaminant in its harvestable parts. vetiver grass (Vetiveria zizanioides) is a fast-growing perennial grass with strong ecological adaptability and large biomass. While this plant is not a hyperaccumulator of arsenic, it has been reported to be able to tolerate and accumulate considerable amounts of arsenic. Being a high biomass, fast-growing plant, vetiver has the potential to be used for arsenic remediation. The present study investigates the potential of vetiver grass to tolerate and accumulate arsenic in soils with varying physico-chemical properties. A greenhouse study is in progress to study the uptake, tolerance and stress response of vetiver grass to inorganic arsenical pesticide. A column study was set up using 5 soils (Eufaula, Millhopper, Orelia, Orla, and Pahokee Muck) contaminated with sodium arsenite at 4 different concentrations of

  17. The Effect of Thiosulphate on Arsenic Bioavailability in a Multi Contaminated Soil. A Novel Contribution to Phytoextraction

    Directory of Open Access Journals (Sweden)

    Gianniantonio Petruzzelli

    2014-01-01

    Full Text Available In this study it was evaluated on a laboratory scale (microcosm, the possibility of using ammonium thiosulphate in assisted phytoextraction for the simultaneous removal of mercury and arsenic from multi-contaminated industrial soil. The species selected were Brassica juncea and Lupinus albus the addition of thiosulfate to the soil greatly promoted the uptake and translocation of both contaminants in the aerial parts of the plants. Mercury concentration in the aerial parts reached in B. juncea 120 mg/kg approximately 40 times the value of the control. The concentration of arsenic also increased significantly in the shoots of B. juncea (14.3 mg/kg, where the value in the control was negligible. Similar trends were obtained for L. albus The results confirmed the known positive effects of thiosulphate in increasing mercury bioavailability for plants, moreover they showed the ability of thiosulphate to mobilize arsenic and significantly to promote its uptake by plants. The increase of arsenic bioavailability, promoted by thiosulfate addition, could be attributed to the competition between arsenate and sulphate ions for the same active sites in the soil surfaces, with the release of arsenic in the soil solution. The use of thiosulfate appears to have great potential since it is a common fertilizer used to promote plant growth and is able to increase the uptake by plants of mercury and arsenic. The simultaneous increase of both contaminants uptake by plants, using a single additive, will provide new insights into the phytoextraction technology in terms of cost and time reduction.

  18. ARSENIC SPECIATION IN CARROT EXTRACTS WITH AN EMPHASIS ON THE DETECTION OF MMA(III) AND MMTA

    Science.gov (United States)

    The two predominant routes of arsenic exposure are dietary ingestion and drinking water consumption. Dietary arsenic, unlike drinking water arsenic, contains a variety of arsenicals with dramatically different toxicities. The list of arsenicals detected in dietary samples conti...

  19. Arsenic contamination and arsenicosis in China

    International Nuclear Information System (INIS)

    Arsenicosis is a serious environmental chemical disease in China mainly caused by drinking water from pump wells contaminated by high levels of arsenic. Chronic exposure of humans to high concentrations of arsenic in drinking water is associated with skin lesions, peripheral vascular disease, hypertension, blackfoot disease, and high risk of cancers. Lead by the Ministry of Health of China, we carried out a research about arsenicosis in China recently. Areas contaminated with arsenic from drinking water are determined by 10% pump well water sample method while areas from burning coal are determined by existing data. Two epidemic areas of Shanxi Province and Inner Mongolia are investigated for the distribution of pump wells containing high arsenic. Well water in all the investigated villages of Shanxi Province showed polluted by high arsenic, and the average rate of unsafe pump well water is 52%. In Inner Mongolia, the high percentage of pump wells containing elevated arsenic is found only in a few villages. The average rate of unsafe pump well water is 11%. From our research, we find that new endemic areas are continuously emerging in China. Up to now, epidemic areas of arsenicosis mainly involve eight provinces and 37 counties in China. In the affected areas, the discovery of wells and coal with high levels of arsenic is continuing sporadically, and a similar scattered distribution pattern of patients is also being observed

  20. [Competitive Microbial Oxidation and Reduction of Arsenic].

    Science.gov (United States)

    Yang, Ting-ting; Bai, Yao-hui; Liang, Jin-song; Huo, Yang; Wang, Ming-xing; Yuan, Lin-ijang

    2016-02-15

    Filters are widely applied in drinking water treatment plants. Our previous study, which explored the asenic redox in a filter of drinking water plant treating underground water, found that As3+ could be oxidized to As5+ by biogenic manganese oxides, while As5+ could be reduced to As3+ by some microbial arsenic reductases in the biofilter system. This microbial competition could influence the system stability and treatment efficiency. To explore its mechanism, this study selected a manganese-oxidizing bacterial strain (Pseudomonas sp. QJX-1) and a arsenic-reducing strain (Brevibacterium sp. LSJ-9) to investigate their competitive relationship in nutrient acquisition and arsenic redox in the presence of Mn2+, As3+ or As5+ The results revealed that the concentration and valence of Mn and As varied with different reaction time; biological manganese oxides dominated the arsenic redox by rapidly oxidizing the As3+ in the existing system and the As3+ generated by arsenic reductase into As. PCR and RT-PCR results indicated that the arsenic reductase (arsC) was inhibited by the manganese oxidase (cumA). The expression of 16S rRNA in QJX-1 was two orders of magnitude higher than that in LSJ-9, which implied QJX-1 was dominant in the bacterial growth. Our data revealed that hydraulic retention time was critical to the valence of arsenic in the effluent of filter in drinking water treatment plant. PMID:27363151

  1. Arsenic adsorption of lateritic soil, limestone powder, lime and fly ash on arsenic-contaminated soil

    Directory of Open Access Journals (Sweden)

    Wuthiphun, L.

    2007-05-01

    Full Text Available Arsenic adsorption efficiency of soil covering materials (lateritic soil, limestone powder, lime and fly ash on arsenic-contaminated soil obtained from Ronpiboon District, Nakhon Sri Thammarat Province tosolve arsenic air pollution problem was investigated using batch experiments. The four types of the aforementioned soil covering materials were examined to determine their arsenic adsorption efficiency, equilibriumtime as well as adsorption isotherms.The results revealed that among soil covering materials mixed with arsenic-contaminated soil at 10% w/w, the efficiency of arsenic adsorption of fly ash, lateritic soil, lime and limestone powder were 84, 60,38 and 1% respectively. The equilibrium time for lateritic soil at pH 4 was achieved within 4 hrs, whereas pH 7 and 12, the equilibrium time was 6 hrs. For fly ash, 2 hrs were required to reach the equilibrium at pH 12, while the equilibrium time was attained within 6 hrs at pH 4 and 7. Furthermore, lateritic soil possessedhigh arsenic adsorption efficiency at pH 7 and 4 and best fit with the Langmuir isotherm. The fly ash showing high arsenic adsorption efficiency at pH 12 and 7 fit the Freundlich isotherm at pH 12 and Langmuirisotherm at pH 7.This indicated that lateritic soil was suitable for arsenic adsorption at low pH, whilst at high pH,arsenic was well adsorbed by fly ash. The Freundlich and Langmuir isotherm could be used to determine quantities of soil covering materials for arsenic adsorption to prevent arsenic air pollution from arseniccontaminated soils.

  2. Current Status and Prevention Strategy for Coal-arsenic Poisoning in Guizhou, China

    OpenAIRE

    Li, Dasheng; An, Dong; Zhou, Yunsu; Liu, Jie; Waalkes, Michael P.

    2006-01-01

    Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnos...

  3. Inorganic arsenic in drinking water accelerates N-butyl-N-(4-hydroxybutyl)nitrosamine-induced bladder tissue damage in mice

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Paul-Yann [Department of Pathology, Chang Gung Memorial Hospital at Chiayi, Chang Gung University, Chiayi, Taiwan (China); Lin, Yung-Lun; Huang, Chin-Chin; Chen, Sin-Syu [Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan (China); Liu, Yi-Wen, E-mail: ywlss@mail.ncyu.edu.tw [Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan (China)

    2012-02-15

    Epidemiological studies have revealed that exposure to an arsenic-contaminated environment correlates with the incidence of bladder cancer. Bladder cancer is highly recurrent after intravesical therapy, and most of the deaths from this disease are due to invasive metastasis. In our present study, the role of inorganic arsenic in bladder carcinogenesis is characterized in a mouse model. This work provides the first evidence that inorganic arsenic in drinking water promotes N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder tissue damage, including the urothelium and submucosal layer. This damage to the bladder epithelium induced by BBN includes thickening of the submucosal layer, the loss of the glycosaminoglycan layer and an increase in both the deoxyguanosine oxidation and cytosine methylation levels in the DNA. Further, when 10 ppm inorganic arsenic is combined with BBN, the number of bladder submucosal capillaries is increased. In addition, inorganic arsenic also increases the deoxyguanosine oxidation level, alters the cytosine methylation state, decreases the activities of glutathione reductase and glucose-6-phosphate dehydrogenase, decreases the protein expression of NAD(P)H quinone oxidoreductase-1 (NQO-1) and increases the protein expression of specific protein 1 (Sp1) in bladder tissues. In summary, our data reveal that inorganic arsenic in drinking water promotes the BBN-induced pre-neoplastic damage of bladder tissue in mice, and that the 8-hydroxy-2′-deoxyguanosine, 5-methylcytosine, NQO-1 protein and Sp1 protein levels may be pre-neoplastic markers of bladder tumors. -- Highlights: ► The role of inorganic arsenic in bladder carcinogenesis is characterized in mice. ► We examine the changes in the histology and biochemistry of bladder tissues. ► Inorganic arsenic enhances BBN-induced DNA oxidation while decreases BBN-induced DNA methylation in the mouse bladder. ► Inorganic arsenic alters the activities of the anti-oxidant enzymes in

  4. Environmental arsenic exposure and sputum metalloproteinase concentrations.

    OpenAIRE

    Josyula, Arun B.; Poplin, Gerald S.; Kurzius-Spencer, Margaret; McClellen, Hannah E.; Kopplin, Michael J.; Stürup, Stefan; Clark Lantz, R.; Jefferey L. Burgess

    2006-01-01

    Biomarkers of exposure & early effects: field studiesBiomarker: arsenic, creatinin, MMP levelsExposure/effect represented: arsenicStudy design: cross-sectionalStudy size: 73 subjectsAnalytical technique: ELISA, HPLCTissue/biological material/sample size: urine samplesRelationship with exposure or effect of interest (including dose-response): inorganic arsenic positively correlated with logMMP-9/TIMP-1 ratio in sputum (Pearson's r Ό 0:351, P Ό 0:009) and negatively correlated with the log of s...

  5. Electrochemical arsenic remediation for rural Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Addy, Susan Amrose [Univ. of California, Berkeley, CA (United States)

    2008-01-01

    Arsenic in drinking water is a major public health problem threatening the lives of over 140 million people worldwide. In Bangladesh alone, up to 57 million people drink arsenic-laden water from shallow wells. ElectroChemical Arsenic Remediation(ECAR) overcomes many of the obstacles that plague current technologies and can be used affordably and on a small-scale, allowing for rapid dissemination into Bangladesh to address this arsenic crisis. In this work, ECAR was shown to effectively reduce 550 - 580 μg=L arsenic (including both As[III]and As[V]in a 1:1 ratio) to below the WHO recommended maximum limit of 10 μg=L in synthetic Bangladesh groundwater containing relevant concentrations of competitive ions such as phosphate, silicate, and bicarbonate. Arsenic removal capacity was found to be approximately constant within certain ranges of current density, but was found to change substantially between ranges. In order of decreasing arsenic removal capacity, the pattern was: 0.02 mA=cm2> 0.07 mA=cm2> 0.30 - 1.1 mA=cm2> 5.0 - 100 mA=cm2. Current processing time was found to effect arsenic removal capacity independent of either charge density or current density. Electrode polarization studies showed no passivation of the electrode in the tested range (up to current density 10 mA=cm2) and ruled out oxygen evolution as the cause of decreasing removal capacity with current density. Simple settling and decantation required approximately 3 days to achieve arsenic removal comparable to filtration with a 0.1 mu m membrane. X-ray Absorption Spectroscopy (XAS) showed that (1) there is no significant difference in the arsenic removal mechanism of ECAR during operation at different current densities and (2) the arsenic removal mechanism in ECAR is consistent with arsenate adsorption onto a homogenous Fe(III)oxyhydroxide similar in structure to 2-line ferrihydrite. ECAR effectively reduced high arsenic concentrations (100

  6. Electrochemical arsenic remediation for rural Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Addy, Susan Amrose

    2009-01-01

    Arsenic in drinking water is a major public health problem threatening the lives of over 140 million people worldwide. In Bangladesh alone, up to 57 million people drink arsenic-laden water from shallow wells. ElectroChemical Arsenic Remediation(ECAR) overcomes many of the obstacles that plague current technologies and can be used affordably and on a small-scale, allowing for rapid dissemination into Bangladesh to address this arsenic crisis. In this work, ECAR was shown to effectively reduce 550 - 580 mu g=L arsenic (including both As[III]and As[V]in a 1:1 ratio) to below the WHO recommended maximum limit of 10 mu g=L in synthetic Bangladesh groundwater containing relevant concentrations of competitive ions such as phosphate, silicate, and bicarbonate. Arsenic removal capacity was found to be approximately constant within certain ranges of current density, but was found to change substantially between ranges. In order of decreasing arsenic removal capacity, the pattern was: 0.02 mA=cm2> 0.07 mA=cm2> 0.30 - 1.1 mA=cm2> 5.0 - 100 mA=cm2. Current processing time was found to effect arsenic removal capacity independent of either charge density or current density. Electrode polarization studies showed no passivation of the electrode in the tested range (up to current density 10 mA=cm2) and ruled out oxygen evolution as the cause of decreasing removal capacity with current density. Simple settling and decantation required approximately 3 days to achieve arsenic removal comparable to filtration with a 0.1 mu m membrane. X-ray Absorption Spectroscopy (XAS) showed that (1) there is no significant difference in the arsenic removal mechanism of ECAR during operation at different current densities and (2) the arsenic removal mechanism in ECAR is consistent with arsenate adsorption onto a homogenous Fe(III)oxyhydroxide similar in structure to 2-line ferrihydrite. ECAR effectively reduced high arsenic concentrations (100 - 500 mu g=L) in real Bangladesh tube well water

  7. Arsenic in rice: A cause for concern

    DEFF Research Database (Denmark)

    Hojsak, Iva; Braegger, Christian; Bronsky, Jiri;

    2015-01-01

    Inorganic arsenic intake is likely to affect long-term health. High concentrations are found in some rice-based foods and drinks widely used in infants and young children. In order to reduce exposure we recommend avoidance of rice drinks for infants and young children. For all rice products, strict...... regulation should be enforced regarding arsenic content. Moreover, infants and young children should consume a balanced diet including a variety of grains as carbohydrate sources. While rice protein based infant formulas are an option for infants with cows' milk protein allergy, the inorganic arsenic content...

  8. Arsenic(III) Immobilization on Rice Husk

    OpenAIRE

    Malay Chaudhuri; Mohammed Ali Mohammed

    2013-01-01

    A number of large aquifers in various parts of the world have been identified with contamination by arsenic. Long-term exposure to arsenic in drinking water causes cancer of the skin, lungs, urinary bladder and kidney, as well as skin pigmentation and hyperkeratosis. Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III)] and pentavalent arsenate [As(V)]. As(III) is more toxic and more difficult to remove from water by adsorption on activated alumina. In this stud...

  9. [Attenuation effects of compatible medicines on arsenical and lead toxicity of badu shengji san].

    Science.gov (United States)

    Lu, Yanli; He, Rong; Peng, Bo; Gao, Jie; Li, Jianrong

    2011-08-01

    Badu Shengji San(BDSJS) is a traditional Chinese medicine (TCM) used for drawing out toxin, eliminating suppuration and promoting granulation. Toxic minerals such as arsenic and lead are the two most important components of BDSJS. Previous hypothesis indicated that according to the compatibility theory of TCM, the toxicity of the entire BDSJS was weaker than that of arsenic and lead, respectively. In the present study, SD rats with injured skin were treated with distilled water and different composition of BDSJS (complete formulations, compatible herbs, mineral medicine containing arsenic and lead, mineral medicine containing arsenic and mineral medicine containing lead) once a day for consecutive 2 weeks. Kidney coefficient and urinary beta-N-acetyl glucosidase (NAG) were used as the indicators of renal toxicity and the content of malondiadehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), glutathione (GSH) and metallothionein (MT) in the renal tissue were measured. Our data showed that kidney coefficient, the severity of renal pathological lesion and MT level in the kidney of the entire BDSJS group decreased significantly compared with arsenic and lead group. Additionally, the NAG content of the entire BDSJS group had the decreased trend. The kidney CuZn-SOD level of the entire BDSJS group had the increased trend, but the MDA, GSH-PX, GSH level had no obvious difference. Our results suggested that compatible herbs in BDSJS relieved renal injury induced by arsenic and lead, and the attenuation mechanism may be related to MT and CuZn-SOD, but not to MDA, GSH-PX and GSH directly. PMID:22066453

  10. [Advance on oxidative stress mechanism of arsenic toxicology].

    Science.gov (United States)

    Li, Zhen; An, Yan

    2009-09-01

    Inorganic arsenic is one of proven human carcinogens, which there are so far no sound laboratory-based evidences and there are very few reports in the literature regarding arsenic carcinogenic effects in in vivo animal experiment. Because of this lack of adequate evidences, the mechanism for understanding arsenic toxicology remains vague. Recently, many modes of action for arsenic carcinogenesis have been proposed, oxidative stress is one of the stronger theories of arsenic action modes which have a substantial mass of supporting data. Further more, many researchers have pointed out that induction of oxidative stress by methylated metabolites of inorganic arsenics plays an important role in the toxicity and carcinogenicity of arsenics. The role of oxidative stress induced by arsenic in arsenic toxicology was reviewed. PMID:19877531

  11. Global Atmospheric Transport and Source-Receptor Relationships for Arsenic.

    Science.gov (United States)

    Wai, Ka-Ming; Wu, Shiliang; Li, Xueling; Jaffe, Daniel A; Perry, Kevin D

    2016-04-01

    Arsenic and many of its compounds are toxic pollutants in the global environment. They can be transported long distances in the atmosphere before depositing to the surface, but the global source-receptor relationships between various regions have not yet been assessed. We develop the first global model for atmospheric arsenic to better understand and quantify its intercontinental transport. Our model reproduces the observed arsenic concentrations in surface air over various sites around the world. Arsenic emissions from Asia and South America are found to be the dominant sources for atmospheric arsenic in the Northern and Southern Hemispheres, respectively. Asian emissions are found to contribute 39% and 38% of the total arsenic deposition over the Arctic and Northern America, respectively. Another 14% of the arsenic deposition to the Arctic region is attributed to European emissions. Our results indicate that the reduction of anthropogenic arsenic emissions in Asia and South America can significantly reduce arsenic pollution not only locally but also globally. PMID:26906891

  12. Mathematical model insights into arsenic detoxification

    Directory of Open Access Journals (Sweden)

    Nijhout H Frederik

    2011-08-01

    Full Text Available Abstract Background Arsenic in drinking water, a major health hazard to millions of people in South and East Asia and in other parts of the world, is ingested primarily as trivalent inorganic arsenic (iAs, which then undergoes hepatic methylation to methylarsonic acid (MMAs and a second methylation to dimethylarsinic acid (DMAs. Although MMAs and DMAs are also known to be toxic, DMAs is more easily excreted in the urine and therefore methylation has generally been considered a detoxification pathway. A collaborative modeling project between epidemiologists, biologists, and mathematicians has the purpose of explaining existing data on methylation in human studies in Bangladesh and also testing, by mathematical modeling, effects of nutritional supplements that could increase As methylation. Methods We develop a whole body mathematical model of arsenic metabolism including arsenic absorption, storage, methylation, and excretion. The parameters for arsenic methylation in the liver were taken from the biochemical literature. The transport parameters between compartments are largely unknown, so we adjust them so that the model accurately predicts the urine excretion rates of time for the iAs, MMAs, and DMAs in single dose experiments on human subjects. Results We test the model by showing that, with no changes in parameters, it predicts accurately the time courses of urinary excretion in mutiple dose experiments conducted on human subjects. Our main purpose is to use the model to study and interpret the data on the effects of folate supplementation on arsenic methylation and excretion in clinical trials in Bangladesh. Folate supplementation of folate-deficient individuals resulted in a 14% decrease in arsenicals in the blood. This is confirmed by the model and the model predicts that arsenicals in the liver will decrease by 19% and arsenicals in other body stores by 26% in these same individuals. In addition, the model predicts that arsenic

  13. 55th electric science promotion prize (progress prize). Demonstration of optical soliton transmission on OPGW first in the world; Dai 55 kai denki gakujutsu shinkosho (shinposho) jusho. Seiaihatsu no OPGW ni okeru hikari soriton denso no jissho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-10

    Electric science promotion prize (progress prize) is given to `Person who newly proposed a new concept, theory, material, device, system and method on electrical science and technology, or demonstrated these proposals` by the commendation committee of Institute of Electrical Engineers of Japan every year. Eight promotion prizes including that for Kansai Electric Power`s `Demonstration of optical soliton transmission on OPGW first in the world` were given. This research succeeded in development of the transmission/ receiving device suitable for optical soliton transmission, and the prediction method of an optimum transmission condition by computer simulation. In addition, this research succeeded in 10Gbit transmission of 784km and 40Gbit transmission (4-wave multiplex) of 392km by applying the above research result to Okurobe trunk line OPGW (98.2km). This demonstration of optical soliton transmission on OPGW is first in the world. (NEDO)

  14. 14-3-3ζ Cooperates with ErbB2 to Promote Progression of Ductal Carcinoma in Situ to Invasive Breast Cancer by Inducing Epithelial-Mesenchymal Transition

    OpenAIRE

    LU, JING; Guo, Hua; Treekitkarnmongkol, Warapen; Ping LI; Zhang, Jian; Shi, Bin; Ling, Chen; ZHOU, XIAOYAN; Chen, Tongzhen; Chiao, Paul J.; Feng, XinHua; Seewaldt, Victoria L.; Muller, William J; Sahin, Aysegul; Hung, Mien-Chie

    2009-01-01

    ErbB2, a metastasis-promoting oncoprotein, is overexpressed in ~25% of invasive/metastatic breast cancers, but in 50–60% of non-invasive ductal carcinomas in situ (DCIS). It has been puzzling how a subset of ErbB2-overexpressing DCIS develops into invasive breast cancer (IBC). We found that co-overexpression of 14-3-3ζ in ErbB2-overexpressing DCIS conferred a higher risk of progression to IBC. ErbB2 and 14-3-3ζ overexpression, respectively, increased cell migration and decreased cell adhesion...

  15. Manufacture of high purity low arsenic anhydrous hydrogen fluoride

    International Nuclear Information System (INIS)

    A process for manufacturing anhydrous hydrogen fluoride with reduced levels of arsenic impurity from arsenic contaminated anhydrous hydrogen fluoride is described which comprises: (a) contacting the anhydrous hydrogen fluoride with an effective amount of hydrogen peroxide to oxidize the arsenic impurity in the presence of a catalyst which comprises a catalytic amount of (i) molybdenum or an inorganic molybdenum compound and (ii) a phosphate compound, at a temperature and for a period of time sufficient to oxidize volatile trivalent arsenic impurities in the anhydrous hydrogen fluoride to non-volatile pentavalent arsenic compounds, and (b) distilling the resulting mixture and recovering anhydrous hydrogen fluoride with reduced levels of arsenic impurity

  16. MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic.

    Science.gov (United States)

    Stanton, Bruce A; Caldwell, Kathleen; Congdon, Clare Bates; Disney, Jane; Donahue, Maria; Ferguson, Elizabeth; Flemings, Elsie; Golden, Meredith; Guerinot, Mary Lou; Highman, Jay; James, Karen; Kim, Carol; Lantz, R Clark; Marvinney, Robert G; Mayer, Greg; Miller, David; Navas-Acien, Ana; Nordstrom, D Kirk; Postema, Sonia; Rardin, Laurie; Rosen, Barry; SenGupta, Arup; Shaw, Joseph; Stanton, Elizabeth; Susca, Paul

    2015-09-01

    This report is the outcome of the meeting "Environmental and Human Health Consequences of Arsenic" held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13-15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food, and more than 200 million people ingest arsenic via drinking water at concentrations greater than international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 μg/L in public water supplies and the WHO has recommended an upper limit of 10 μg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies. PMID:26231509

  17. Arsenic stress after the Proterozoic glaciations

    Science.gov (United States)

    Chi Fru, Ernest; Arvestål, Emma; Callac, Nolwenn; El Albani, Abderrazak; Kilias, Stephanos; Argyraki, Ariadne; Jakobsson, Martin

    2015-12-01

    Protection against arsenic damage in organisms positioned deep in the tree of life points to early evolutionary sensitization. Here, marine sedimentary records reveal a Proterozoic arsenic concentration patterned to glacial-interglacial ages. The low glacial and high interglacial sedimentary arsenic concentrations, suggest deteriorating habitable marine conditions may have coincided with atmospheric oxygen decline after ~2.1 billion years ago. A similar intensification of near continental margin sedimentary arsenic levels after the Cryogenian glaciations is also associated with amplified continental weathering. However, interpreted atmospheric oxygen increase at this time, suggests that the marine biosphere had widely adapted to the reorganization of global marine elemental cycles by glaciations. Such a glacially induced biogeochemical bridge would have produced physiologically robust communities that enabled increased oxygenation of the ocean-atmosphere system and the radiation of the complex Ediacaran-Cambrian life.

  18. TELOMERASE AND CHRONIC ARSENIC EXPOSURE IN HUMANS

    Science.gov (United States)

    Arsenic exposure has been associated with increased risk of skin, lung and bladder cancer in humans. The mechanisms of carcinogenesis are not well understood. Telomerase, a ribonucleoprotein containing human telomerase reverse transcriptase (hTERT), can extend telomeres of eukary...

  19. Toxicokinetics and Pharmacokinetic Modeling of Arsenic

    Science.gov (United States)

    This chapter provides an overview of arsenic toxicokinetics and physiologically-basedpharmacokinetic (PBPK) modeling with particular emphasis on key 'actors needed fordevelopment of a model useful for dose-response analysis, applications of arsenicmodels, as well research needs.U...

  20. ARSENIC REMOVAL BY SOFTENING AND COAGULATION

    Science.gov (United States)

    Drinking water regulations for arsenic (As) and disinfection by-product precursor materials (measured as TOC) are becoming increasingly stringent. Among the modifications to conventional treatment that can improve removal of As and TOC, precipitative softening and coagulation are...

  1. Speciation of arsenic in water samples

    International Nuclear Information System (INIS)

    Two methods are presented in this report for the determination of inorganic species of arsenic. For both methods, the parameters influencing the separations have been investigated using radiotracers. Following optimization of the methods; the applicability was tested by determining As(III) and As(V) in real water samples. The detection limit of these arsenic species in both fresh and sea water was about 0.02 μg/L. (author). 2 refs, 3 figs, 3 tabs

  2. Arsenic Induced Decreases in the Vascular Matrix

    OpenAIRE

    Hays, Allison M.; Lantz, R. Clark; Rodgers, Laurel S.; Sollome, James J.; Vaillancourt, Richard R.; Andrew, Angeline S; Hamilton, Joshua W.; Camenisch, Todd D.

    2008-01-01

    Chronic ingestion of arsenic is associated with increased incidence of respiratory and cardiovascular diseases. To investigate the role of arsenic in early events in vascular pathology, C57BL/6 mice ingested drinking water with or without 50 ppb sodium arsenite (AsIII) for four, five or eight weeks. At five and eight weeks, RNA from the lungs of control and AsIII exposed animals was processed for microarray. Sixty-five genes were significantly and differentially expressed. Differential expres...

  3. Arsenic biotransformation and volatilization in transgenic rice

    OpenAIRE

    Meng, Xiang-yan; Qin, Jie; Wang, Li-Hong; Duan, Gui-Lan; Sun, Guo-Xin; Wu, Hui-Lan; Chu, Cheng-Cai; Ling, Hong-Qing; Rosen, Barry P.; Zhu, Yong-Guan

    2011-01-01

    Biotransformation of arsenic includes oxidation, reduction, methylation and conversion to more complex organic arsenicals. Members of the class of arsenite [As(III)] S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di- and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants.Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica r...

  4. Arsenic: Not So Evil After All?

    Science.gov (United States)

    Lykknes, Annette; Kvittingen, Lise

    2003-05-01

    This article presents parts of the history of the element arsenic in order to illustrate processes behind development of knowledge in chemistry. The particular aspects presented here are the use of arsenic as a stimulant by Styrian peasants, in Fowler's solution, in drugs of the 19th century (e.g., salvarsan), and in current medical treatment, all of which challenge the myth of this element as exclusively poisonous.

  5. Arsenic accumulation in some higher fungi

    OpenAIRE

    Stijve, T.; Vellinga, Else C.; Herrmann, A.

    1990-01-01

    The high arsenic concentrations reported in literature for Laccaria amethystina were amply confirmed. In addition, it was demonstrated that Laccaria fraterna also accumulates the element, whereas in other species of Laccaria the phenomenon was far less outspoken. Few other basidiomycetes proved to have an affinity for the toxic element. The arsenic concentrations in the principal edible mushrooms of commerce were found to be very low, i.e. on the average 0.5 mg/kg on dry matter. Among the asc...

  6. Polymorphism of inflammatory genes and arsenic methylation capacity are associated with urothelial carcinoma

    International Nuclear Information System (INIS)

    Chronic exposure to arsenic can generate reactive oxidative species, which can induce certain proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8). TNF-α, IL-6 and IL-8 have been shown to be involved in the development and progression of various cancers, including bladder cancer. This study aimed to investigate the joint effect of the polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C, IL-8 − 251 T/A and urinary arsenic profiles on urothelial carcinoma (UC) risk. This study evaluated 300 pathologically-confirmed cases of UC and 594 cancer-free controls. Urinary arsenic species were detected using high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C and IL-8 − 251 T/A was determined using polymerase chain reaction-restriction fragment length polymorphism. The joint effects on UC risk were estimated by odds ratios and 95% confidence intervals using unconditional logistic regression. We found that the TNF-α − 308 A/A and IL-8 − 251 T/T polymorphisms were significantly associated with UC. Moreover, significant dose–response joint effect of TNF-α − 308 A/A or IL-8 − 251 T/T genotypes and arsenic methylation indices were seen to affect UC risk. The present results also showed a significant increase in UC risk in subjects with the IL-8 − 251 T/T genotype for each SD increase in urinary total arsenic and MMA%. In contrast, a significant decrease in UC risk was found in subjects who carried the IL-8 − 251 T/T genotype for each SD increase in DMA%. - Highlights: • Joint effect of the TNF-α -308 A/A genotype and urinary total arsenic affected UC. • Joint effect of the IL-8 -251 T/T genotype and urinary total arsenic affected UC. • Urinary total arsenic level, TNF-α -308 A/A and IL-8 -251 T/T genotype affected UC

  7. Polymorphism of inflammatory genes and arsenic methylation capacity are associated with urothelial carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chia-Chang [School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Department of Urology, Taipei Medical University—Shuang Ho Hospital, Taipei, Taiwan (China); Huang, Yung-Kai [School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan (China); Chung, Chi-Jung [Department of Health Risk Management, College of Public Health, China Medical University and Hospital, Taichung, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung, Taiwan (China); Huang, Chao-Yuan; Pu, Yeong-Shiau [Department of Urology, National Taiwan University Hospital, College of Medicine National Taiwan University, Taipei, Taiwan (China); Shiue, Horng-Sheng [Department of Chinese Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan (China); Lai, Li-An [School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Lin, Ying-Chin [Department of Family Medicine, Shung Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Department of Health Examination, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan (China); Su, Chien-Tien [Department of Family Medicine, Taipei Medical University Hospital, Taipei, Taiwan (China); Hsueh, Yu-Mei, E-mail: ymhsueh@tmu.edu.tw [School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

    2013-10-01

    Chronic exposure to arsenic can generate reactive oxidative species, which can induce certain proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8). TNF-α, IL-6 and IL-8 have been shown to be involved in the development and progression of various cancers, including bladder cancer. This study aimed to investigate the joint effect of the polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C, IL-8 − 251 T/A and urinary arsenic profiles on urothelial carcinoma (UC) risk. This study evaluated 300 pathologically-confirmed cases of UC and 594 cancer-free controls. Urinary arsenic species were detected using high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C and IL-8 − 251 T/A was determined using polymerase chain reaction-restriction fragment length polymorphism. The joint effects on UC risk were estimated by odds ratios and 95% confidence intervals using unconditional logistic regression. We found that the TNF-α − 308 A/A and IL-8 − 251 T/T polymorphisms were significantly associated with UC. Moreover, significant dose–response joint effect of TNF-α − 308 A/A or IL-8 − 251 T/T genotypes and arsenic methylation indices were seen to affect UC risk. The present results also showed a significant increase in UC risk in subjects with the IL-8 − 251 T/T genotype for each SD increase in urinary total arsenic and MMA%. In contrast, a significant decrease in UC risk was found in subjects who carried the IL-8 − 251 T/T genotype for each SD increase in DMA%. - Highlights: • Joint effect of the TNF-α -308 A/A genotype and urinary total arsenic affected UC. • Joint effect of the IL-8 -251 T/T genotype and urinary total arsenic affected UC. • Urinary total arsenic level, TNF-α -308 A/A and IL-8 -251 T/T genotype affected UC.

  8. Aquatic arsenic: phytoremediation using floating macrophytes.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-04-01

    Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumulating plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes. PMID:21435676

  9. Earthworms produce phytochelatins in response to arsenic.

    Directory of Open Access Journals (Sweden)

    Manuel Liebeke

    Full Text Available Phytochelatins are small cysteine-rich non-ribosomal peptides that chelate soft metal and metalloid ions, such as cadmium and arsenic. They are widely produced by plants and microbes; phytochelatin synthase genes are also present in animal species from several different phyla, but there is still little known about whether these genes are functional in animals, and if so, whether they are metal-responsive. We analysed phytochelatin production by direct chemical analysis in Lumbricus rubellus earthworms exposed to arsenic for a 28 day period, and found that arsenic clearly induced phytochelatin production in a dose-dependent manner. It was necessary to measure the phytochelatin metabolite concentrations directly, as there was no upregulation of phytochelatin synthase gene expression after 28 days: phytochelatin synthesis appears not to be transcriptionally regulated in animals. A further untargetted metabolomic analysis also found changes in metabolites associated with the transsulfuration pathway, which channels sulfur flux from methionine for phytochelatin synthesis. There was no evidence of biological transformation of arsenic (e.g. into methylated species as a result of laboratory arsenic exposure. Finally, we compared wild populations of earthworms sampled from the field, and found that both arsenic-contaminated and cadmium-contaminated mine site worms had elevated phytochelatin concentrations.

  10. Determination of leachable arsenic from glass ampoules

    International Nuclear Information System (INIS)

    Appreciable amounts of different arsenic compounds are used in the manufacture of glass and glass ampoules (injection vials and bottles) used to store drugs. Exposure/intake of arsenic to human beings may result in skin ulceration, injury to mucous membranes, perforation of nasal septum, skin cancer and keratoses, especially of the palms and soles and may cause detrimental effects. Considering the toxicity of arsenic, even if traces of arsenic from such glass containers/ampoules are leached out, it can impart damage to human beings. To check the possibility of leaching of arsenic from glass ampoules, a simple methodology has been developed. Different makes and varieties of glass ampoules filled with de-ionized water were subjected to high pressure and temperature leaching for varying amount of time using autoclave to create extreme conditions for the maximum leaching out of the analyte. Subsequently, the determination of the arsenic contents in leached water using neutron activation analysis is reported in detail with observations. (author)

  11. Arsenic, reactive oxygen, and endothelial dysfunction.

    Science.gov (United States)

    Ellinsworth, David C

    2015-06-01

    Human exposure to drinking water contaminated with arsenic is a serious global health concern and predisposes to cardiovascular disease states, such as hypertension, atherosclerosis, and microvascular disease. The most sensitive target of arsenic toxicity in the vasculature is the endothelium, and incubation of these cells with low concentrations of arsenite, a naturally occurring and highly toxic inorganic form of arsenic, rapidly induces reactive oxygen species (ROS) formation via activation of a specific NADPH oxidase (Nox2). Arsenite also induces ROS accumulation in vascular smooth muscle cells, but this is relatively delayed because, depending on the vessel from which they originate, these cells often lack Nox2 and/or its essential regulatory cytosolic subunits. The net effect of such activity is attenuation of endothelium-dependent conduit artery dilation via superoxide anion-mediated scavenging of nitric oxide (NO) and inhibition and downregulation of endothelial NO synthase, events that are temporally matched to the accumulation of oxidants across the vessel wall. By contrast, ROS induced by the more toxic organic trivalent arsenic metabolites (monomethylarsonous and dimethylarsinous acids) may originate from sources other than Nox2. As such, the mechanisms through which vascular oxidative stress develops in vivo under continuous exposure to all three of these potent arsenicals are unknown. This review is a comprehensive analysis of the mechanisms that mediate arsenic effects associated with Nox2 activation, ROS activity, and endothelial dysfunction, and also considers future avenues of research into what is a relatively poorly understood topic with major implications for human health. PMID:25788710

  12. A novel arsenic methyltransferase gene of Westerdykella aurantiaca isolated from arsenic contaminated soil: phylogenetic, physiological, and biochemical studies and its role in arsenic bioremediation.

    Science.gov (United States)

    Verma, Shikha; Verma, Pankaj Kumar; Meher, Alok Kumar; Dwivedi, Sanjay; Bansiwal, Amit Kumar; Pande, Veena; Srivastava, Pankaj Kumar; Verma, Praveen Chandra; Tripathi, Rudra Deo; Chakrabarty, Debasis

    2016-03-01

    Elevated arsenic concentration in the environment and agricultural soil is a serious concern to crop production and human health. Among different detoxification mechanisms, the methylation of arsenic is a widespread phenomenon in nature. A number of microorganisms are able to methylate arsenic, but less is known about the arsenic metabolism in fungi. We identified a novel arsenic methyltransferase (WaarsM) gene from a soil fungus, Westerdykella aurantiaca. WaarsM showed sequence homology with all known arsenic methyltransferases having three conserved SAM binding motifs. The expression of WaarsM enhanced arsenic resistance in E. coli (Δars) and S. cerevisiae (Δacr2) strains by biomethylation and required endogenous reductants, preferably GSH, for methyltransferase activity. The purified WaarsM catalyzes the production of methylated arsenicals from both AsIII and AsV, and also displays AsV reductase activity. It displayed higher methyltransferase activity and lower KM 0.1945 ± 0.021 mM and KM 0.4034 ± 0.078 mM for AsIII and AsV, respectively. S. cerevisiae (Δacr2) cells expressing WaarsM produced 2.2 ppm volatile arsenic and 0.64 ppm DMA(v) with 0.58 ppm volatile arsenicals when exposed to 20 ppm AsV and 2 ppm AsIII, respectively. Arsenic tolerance in rice after co-culture with genetically engineered yeast suggested its potential role in arsenic bioremediation. Thus, characterization of WaarsM provides a potential strategy to reduce arsenic concentration in soil with reduced arsenic accumulation in crops grown in arsenic contaminated areas, and thereby alleviating human health risks. PMID:26776948

  13. Effects of arsenic exposure on DNA methylation in cord blood samples from newborn babies and in a human lymphoblast cell line

    Directory of Open Access Journals (Sweden)

    Intarasunanont Ponpat

    2012-05-01

    Full Text Available Abstract Background Accumulating evidence indicates that in utero exposure to arsenic is associated with congenital defects and long-term disease consequences including cancers. Recent studies suggest that arsenic carcinogenesis results from epigenetic changes, particularly in DNA methylation. This study aimed to investigate DNA methylation changes as a result of arsenic exposure in utero and in vitro. Methods For the exposure in utero study, a total of seventy-one newborns (fifty-five arsenic-exposed and sixteen unexposed newborns were recruited. Arsenic concentrations in the drinking water were measured, and exposure in newborns was assessed by measurement of arsenic concentrations in cord blood, nails and hair by Inductively Coupled Plasma Mass Spectrometry (ICP-MS. In the in vitro study, human lymphoblasts were treated with arsenite at 0-100 μM for two, four and eight hours (short-term and at 0, 0.5 and 1.0 μM for eight-weeks period (long-term. DNA methylation was analyzed in cord blood lymphocytes and lymphoblasts treated with arsenite in vitro. Global DNA methylation was determined as LINE-1 methylation using combined bisulfite restriction analysis (COBRA and total 5-methyldeoxycytidine (5MedC content which was determined by HPLC-MS/MS. Methylation of p53 was determined at the promoter region using methylation-specific restriction endonuclease digestion with MspI and HpaII. Results Results showed that arsenic-exposed newborns had significantly higher levels of arsenic in cord blood, fingernails, toenails and hair than those of the unexposed subjects and a slight increase in promoter methylation of p53 in cord blood lymphocytes which significantly correlated with arsenic accumulation in nails (p in vitro arsenite treatment in lymphoblastoid cells clearly demonstrated a significant global hypomethylation, determined as reduction in LINE-1 methylation and total 5-MedC content, and p53 hypermethylation (p in vitro treatment. Conclusions This

  14. Evidence against the nuclear in situ binding of arsenicals-oxidative stress theory of arsenic carcinogenesis

    Science.gov (United States)

    A large amount of evidence suggests that arsenicals act via oxidative stress in causing cancer in humans and experimental animals. It is possible that arsenicals could bind in situ close to nuclear DNA followed by Haber-Weiss type oxidative DNA damage. Therefore, we tested this...

  15. Evidence against the nuclear in situ binding of arsenicals-oxidative stress theory of arsenic carcinogenesis

    International Nuclear Information System (INIS)

    A large amount of evidence suggests that arsenicals act via oxidative stress in causing cancer in humans and experimental animals. It is possible that arsenicals could bind in situ close to nuclear DNA followed by Haber-Weiss type oxidative DNA damage. Therefore, we tested this hypothesis by using radioactive 73As labeled arsenite and vacuum filtration methodology to determine the binding affinity and capacity of 73As arsenite to calf thymus DNA and Type 2A unfractionated histones, histone H3, H4 and horse spleen ferritin. Arsenicals are known to release redox active Fe from ferritin. At concentrations up to about 1 mM, neither DNA nor any of the three proteins studied, Type II-A histones, histone H3, H4 or ferritin, bound radioactive arsenite in a specific manner. Therefore, it appears highly unlikely that initial in situ binding of trivalent arsenicals, followed by in situ oxidative DNA damage, can account for arsenic's carcinogenicity. This experimental evidence (lack of arsenite binding to DNA, histone Type II-A and histone H3, H4) does not rule out other possible oxidative stress modes of action for arsenic such as (a) diffusion of longer lived oxidative stress molecules, such as H2O2 into the nucleus and ensuing oxidative damage, (b) redox chemistry by unbound arsenicals in the nucleus, or (c) arsenical-induced perturbations in Fe, Cu or other metals which are already known to oxidize DNA in vitro and in vivo

  16. DETERMINATION OF URINARY TRIVALENT ARSENICALS (MMASIII AND DMASIII) IN INDIVIDUALS CHRONICALLY EXPOSED TO ARSENIC

    Science.gov (United States)

    DETERMINATION OF URINARY TRIVALENT ARSENICALS (MMAsIII and DMAsIII) IN INDIVIDUALS CHRONICALLY EXPOSED TO ARSENIC. L. M. Del Razo1, M. Styblo2, W. R. Cullen3, and D.J. Thomas4. 1Toxicology Section, Cinvestav-IPN, Mexico, D.F., 2Univ. North Carolina, Chapel Hill, NC; 3Uni...

  17. Arsenic speciation in Chinese Herbal Medicines and human health implication for inorganic arsenic

    International Nuclear Information System (INIS)

    Rice and drinking water are recognized as the dominant sources of arsenic (As) for human intake, while little is known about As accumulation and speciation in Chinese Herbal Medicines (CHMs), which have been available for many hundreds of years for the treatment of diseases in both eastern and western cultures. Inorganic arsenic was the predominant species in all of CHMs samples. The levels of inorganic arsenic in CHMs from fields and markets or pharmacies ranged from 63 to 550 ng/g with a mean of 208 ng/g and 94 to 8683 ng/g with a mean of 1092 ng/g, respectively. The highest concentration was found in the Chrysanthemum from pharmacies. It indicates that the risk of inorganic As in CHMs to human health is higher in medicines from markets or pharmacies than that collected directly from fields. Some CHMs may make a considerable contribution to the human intake of inorganic arsenic. - Highlights: ► Arsenic speciation was extracted using 1% HNO3 in microwave. ► Inorganic arsenic was the predominant species in all of CHMs samples. ► The highest concentration of inorganic arsenic was found in the Chrysanthemum. - Inorganic arsenic was the predominant species in all of CHMs samples.

  18. Soil arsenic in Armadale, Scotland

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.H.; Lloyd, O.L.; Hubbard, F.H.

    1986-03-01

    As part of an investigation into the high mortality from lung cancer and the high sex ratios of births in Armadale, central Scotland, concentrations of arsenic were measured in soil cores from 48 sites in Armadale and 6 sites in a comparison town. Concentrations in Armadale were substantially higher than those in the comparison town, and many of the highest range of values were in that part of the town where the epidemiological abnormalities of lung cancer and of birth sex ratios were most pronounced. The study indicated that clues to the etiology of high rates of disease in small areas could be sought most profitably if close links were maintained between epidemiological and environmental investigations.

  19. Speciated arsenic concentrations, exposure, and associated health risks for rice and bulgur.

    Science.gov (United States)

    Sofuoglu, Sait C; Güzelkaya, Hilal; Akgül, Özlem; Kavcar, Pınar; Kurucaovalı, Filiz; Sofuoglu, Aysun

    2014-02-01

    Arsenic species were determined in rice and bulgur samples that were collected from 50 participants who also supplied exposure related information through a questionnaire survey. Speciation analysis was conducted using an HPLC-ICP-MS system. Ingestion exposure to arsenic and associated health risks were assessed by combining the concentration and questionnaire data both for individual participants and the subject population. Inorganic arsenic dominated both in rice and bulgur but concentrations were about an order of magnitude higher in rice (160±38 ng/g) than in bulgur. Because participants also consumed more rice than bulgur, exposures were significantly higher for rice resulting in carcinogenic risks above acceptable level for 53% and 93% of the participants when the in-effect and the proposed potencies were used, respectively, compared to 0% and 5% for bulgur. An inorganic arsenic standard for rice would be useful to lower the risks while public awareness about the relation between excessive rice consumption and health risks is built, and bulgur consumption is promoted. PMID:24296133

  20. Gene Analysis of Arsenic Trioxide—induced Apoptosis of Lymphoma Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANGZidong; LIWeiyu; 等

    2002-01-01

    Objective The effect of arsenic trioxide on apoptosis gene expression of Raji cell was explored when Raji cells were incubated with 0.5μmol/L of arsenic trioxide for 6h。Methods Cell culture,extraction and isolation of mRNA,preparation of probes labeled with fluorescence,hybridization technique of DNA chip(each chip containing 200 apoptosis genes,Chinese Shanghai Biostar,In.)were used.Results Arsenic trioxide induced significant changes in 10%(20/200 genes)of the apoptosis genes:18 genes were downregulated,only two upregulated.In particular,inhibitors of apoptosis protein,such as X-linked inhibitor of apoptosis protein,were significantly downregulated.P53 and the other apoptosis genes were also downregulatec.Of the upregulated genes,high expression of heat-shock protein could promote apoptosis of Raji cells.Conclusion The inhibitors of apoptosis protein play an important role in the process of arsenic trioxide-induced apoptosis of Raji cells.

  1. Arsenic emission during combustion of high arsenic coals from Southwestern Guizhou, China

    International Nuclear Information System (INIS)

    With the aim of better understanding the distribution of arsenic, 144 coal samples were collected from southwestern Guizhou, and the concentrations of arsenic were determined by atomic fluorescence spectrometry (AFS) and inductively coupled plasma mass spectrometry (ICP-MS). The content of arsenic varies from 0.3 ppm to 3.2 wt.%. In most coal samples, the arsenic content was lower than 30 ppm, which was close to a representative value of arsenic concentration of coal in China. Arsenic contents in 37 samples, which were from several small coal mines, were more than 30 ppm, among which only 16 samples were more than 100 ppm, and only a few samples contained more than 1000 ppm, which were very restricted and the coal seams were generally unworkable. Combustion of two kinds of high arsenic coal with and without CaO additive was studied in a bench scale drop tube furnace (DTF) to understand the partition and emission of arsenic in the process. The PM was size segregated by low pressure impactor (LPI) into 13 size stages ranging from 9.8 to 0.0281 μm. X-ray fluorescence spectrometry (XRF) was used to determine the chemical composition of the PM, and inductively coupled plasma atomic emission spectrometry (ICP-AES) was used to determine the arsenic content. A bimodal mode distribution of the PM was formed during coal combustion; the large mode (coarse particle) was formed at 4.0 μm, and the other mode (fine particles) was at about 0.1 μm. A middle mode was gradually obvious in high temperature for both of the two coal combustions, which may have been derived from coagulation and agglomeration of metal elements vapors. More gaseous arsenic was formed in 50% oxygen content than 20% oxygen content. Arsenic in sulfide is easier to vaporize than as arsenate. Along with the increasing temperature from 1100 oC to 1400 oC, the arsenic concentration in PM1 increased from 0.07 mg/N m3 to 0.25 mg/N m3. With the addition of the calcium based sorbent, the arsenic concentration in

  2. Adsorption of sodium lauryl sulfate onto arsenic-bearing ferrihydrite.

    Science.gov (United States)

    Quan, C; Khoe, G; Bagster, D

    2001-02-01

    Ferrihydrite is an excellent adsorbent for binding trace toxic contaminants such as arsenic, and precipitate flotation of the arsenic-bearing ferrihydrite has been studied. Anionic surfactants such as sodium lauryl sulfate (SLS) and sodium oleate (NaOL) are suitable collectors for the flotation. The adsorption of SLS both alone and after the subsequent addition of NaOL on these precipitates at pH 4-5 was measured. It has been shown that the synergistic effect of the two surfactants on flotation is dependent on their addition order. The presence of NaOL before SLS in the conditioning stage can prevent the adsorption of SLS because of the electrostatic shielding of adsorption sites on the precipitates. The post addition of NaOL to the SLS-bearing precipitates can promote the flocculation of the precipitates and enhance entrainment of SLS for better flotation. The SLS adsorption data fit better with the modified Frumkin isotherm than the Langmuir isotherm. Thermodynamic parameters (-delta Gads0,delta Hads0, and delta Sads0) have been derived from the analysis of the adsorption isotherms. The results suggest that the adsorption of SLS on AFH is physical and exothermic. PMID:11229002

  3. Geochemical fate of arsenic in swine litter

    Science.gov (United States)

    Quazi, S.; Makris, K.; Sarkar, D.; Datta, R.; Punamiya, P.

    2007-12-01

    Swine diet is often supplemented by organoarsenicals, such as roxarsone to treat diseases and to promote growth. Recent data reported roxarsone degradation under anaerobic conditions in poultry litter, but no such data exist for swine wastes typically stored in unprotected lagoons in concentrated animal feeding operations (CAFOs). However, serious environmental health risk may arise upon significant arsenic (As) release into solution. The problem may be exacerbated under certain environmental conditions where organoarsenicals, such as roxarsone transform into the more toxic inorganic As, posing serious health risk to the surrounding ecosystem. The objective of this study were to analyze swine wastes collected from 19 randomly selected CAFOs in the USA for As concentrations, and to determine the geochemical fate of As in the swine waste suspensions. Swine wastes were analyzed for total-recoverable, total soluble, and water-extractable As, which were measured by ICP-MS. Speciation of As was performed following a well-established hyphenated technique using HPLC- ICPMS. Swine waste suspensions differed in solids contents; thus, the particulate matters with varying As concentrations were spiked with roxarsone and incubated under dark/light and aerobic/anaerobic conditions. Findings show the prevalence of inorganic As [As(V)] in swine waste suspension solutions. Roxarsone underwent degradation to both organoarsenicals, such as p-ASA, as well as inorganic arsenate and to a number of unidentified metabolites. Roxarsone degradation kinetics was influenced by the solids content and the air conditions (anaerobic/aerobic) of the swine waste suspensions. Maximum degradation rates were observed under anaerobic conditions, in suspensions which were low in solids content. Roxarsone degradation was primarily microbially-mediated, but in certain cases abiotic degradation was also observed, which were significantly slower.

  4. Progress on Stress Tolerance Promoters in Plants%植物逆境胁迫耐受性启动子的研究进展

    Institute of Scientific and Technical Information of China (English)

    张晶红; 那杰

    2014-01-01

    Abiotic and biotic stresses, including drought, extreme temperature, damage and many diseases, seri-ously affected plants growth and yield. Stress-tolerance promoter could accept signals induced by stress condi-tions, and activate the expression of stress responsive gene in plants, enabling plants to perceive and adapt to adversity. In this article, current research on cloning and function of stress-tolerance promoters were reviewed, including drought-resistant, salt-tolerance, high-temperature-resistant, damage-tolerance, cold-resistant, dis-ease-resistant and insect-resistant promoters.%逆境胁迫如干旱、极端温度、损伤等非生物胁迫和病虫害等生物胁迫严重影响植物的生长发育及产量。逆境胁迫耐受性启动子能够接受逆境条件下的诱导信号,激活植物体内胁迫应答基因的表达,使植物感知并适应逆境。本文对逆境胁迫耐受性启动子的克隆及功能研究情况进行综合分析,主要包括抗旱、耐盐、耐高温、抗冻、耐损伤、抗病和抗虫基因启动子。

  5. Tumor-produced versican V1 enhances hCAP18/LL-37 expression in macrophages through activation of TLR2 and vitamin D3 signaling to promote ovarian cancer progression in vitro.

    Directory of Open Access Journals (Sweden)

    Dong Li

    Full Text Available Tumor-associated macrophages have been shown to promote tumor growth. They may have an obligatory function in angiogenesis, invasion, and metastasis through release of inflammatory mediators. Their presence in ovarian cancer has been correlated with poor prognosis in these patients. The human cationic antimicrobial protein-18 (hCAP18/LL-37 was originally identified as an effector molecule of the innate immune system. It is released by innate immune cells, such as macrophages, to combat microorganisms. Previous studies have characterized the hCAP18/LL-37 as a growth factor that has been shown to promote ovarian tumor progression. However, the role hCAP18/LL-37 has in macrophage-promoted ovarian tumor development and how its expression is controlled in this context remains poorly understood. Here, we demonstrate in co-culture experiments of macrophages and ovarian cancer cells a significant increase in the in vitro proliferation and invasiveness of the tumor cells is observed. These enhanced growth and invasion properties correlated with hCAP18/LL-37 induction. HCAP18/LL-37 expression was diminished by addition of two neutralizing antibodies, TLR2 or TLR6, as well as Cyp27B1 or VDR inhibitors. Furthermore, either the TLR2 or TLR6 antibody reduced vitamin D3 signaling and tumor cell progression in vitro. Addition of Cyp27B1 or VDR inhibitors abrogated TLR2/6 activation-induced expression of hCAP18/LL-37 in macrophages. Knockdown of tumor-produced versican V1 by RNAi in these tumor cells led to a decreased induction of hCAP18/LL-37 in macrophages. Versican V1 knockdown also inhibited TLR2 and vitamin D3 signaling, as well as growth and invasiveness of these tumor cells in the in vitro co-culture. In summary, we have found that versican V1 enhances hCAP18/LL-37 expression in macrophages through activation of TLR2 and subsequent vitamin D-dependent mechanisms which promote ovarian tumor progression in vitro.

  6. Arsenic concentrations, related environmental factors, and the predicted probability of elevated arsenic in groundwater in Pennsylvania

    Science.gov (United States)

    Gross, Eliza L.; Low, Dennis J.

    2013-01-01

    Analytical results for arsenic in water samples from 5,023 wells obtained during 1969–2007 across Pennsylvania were compiled and related to other associated groundwater-quality and environmental factors and used to predict the probability of elevated arsenic concentrations, defined as greater than or equal to 4.0 micrograms per liter (µg/L), in groundwater. Arsenic concentrations of 4.0 µg/L or greater (elevated concentrations) were detected in 18 percent of samples across Pennsylvania; 8 percent of samples had concentrations that equaled or exceeded the U.S. Environmental Protection Agency’s drinking-water maximum contaminant level of 10.0 µg/L. The highest arsenic concentration was 490.0 µg/L. Comparison of arsenic concentrations in Pennsylvania groundwater by physiographic province indicates that the Central Lowland physiographic province had the highest median arsenic concentration (4.5 µg/L) and the highest percentage of sample records with arsenic concentrations greater than or equal to 4.0 µg/L (59 percent) and greater than or equal to 10.0 µg/L (43 percent). Evaluation of four major aquifer types (carbonate, crystalline, siliciclastic, and surficial) in Pennsylvania showed that all types had median arsenic concentrations less than 4.0 µg/L, and the highest arsenic concentration (490.0 µg/L) was in a siliciclastic aquifer. The siliciclastic and surficial aquifers had the highest percentage of sample records with arsenic concentrations greater than or equal to 4.0 µg/L and 10.0 µg/L. Elevated arsenic concentrations were associated with low pH (less than or equal to 4.0), high pH (greater than or equal to 8.0), or reducing conditions. For waters classified as anoxic (405 samples), 20 percent of sampled wells contained water with elevated concentrations of arsenic; for waters classified as oxic (1,530 samples) only 10 percent of sampled wells contained water with elevated arsenic concentrations. Nevertheless, regardless of the reduction

  7. Arsenic-Induced Genotoxicity and Genetic Susceptibility to Arsenic-Related Pathologies

    Directory of Open Access Journals (Sweden)

    Fabrizio Bianchi

    2013-04-01

    Full Text Available The arsenic (As exposure represents an important problem in many parts of the World. Indeed, it is estimated that over 100 million individuals are exposed to arsenic, mainly through a contamination of groundwaters. Chronic exposure to As is associated with adverse effects on human health such as cancers, cardiovascular diseases, neurological diseases and the rate of morbidity and mortality in populations exposed is alarming. The purpose of this review is to summarize the genotoxic effects of As in the cells as well as to discuss the importance of signaling and repair of arsenic-induced DNA damage. The current knowledge of specific polymorphisms in candidate genes that confer susceptibility to arsenic exposure is also reviewed. We also discuss the perspectives offered by the determination of biological markers of early effect on health, incorporating genetic polymorphisms, with biomarkers for exposure to better evaluate exposure-response clinical relationships as well as to develop novel preventative strategies for arsenic- health effects.

  8. Improvement of bioreporter bacteria-based test systems for the analysis of arsenic in drinking water and the rhizosphere

    International Nuclear Information System (INIS)

    Contamination of drinking water with arsenic can be measured in laboratories with atom absorption spectrometry (AAS), mass spectrometry with inductive coupled plasma (ICP-MS) or atom fluorescence spectrometry (AFS) at the relevant concentrations below 50 μg/L. Field test kits which easily and reliably measure arsenic concentrations are not yet available. Test systems on the basis of bioreporter bacteria offer an alternative. Based on the natural resistance mechanism of bacteria against arsenic compounds toxic for humans, bioreporter bacteria can be constructed that display arsenic concentrations with light emission (luminescence or fluorescence) or colour reactions. This is achieved by coupling the gene for the ArsR-protein and arsenic regulated promoters with suitable reporter genes. The resulting bioreporter bacteria report bioavailable arsenic in a dose dependent manner at the toxicologically relevant level of 2 to 80 μg/L and are therewith suitable both for the guideline levels of the WHO of 10 μg/L and for the national standards in South East Asia of 50 μg/L. This alternative method has the advantage of being independent from sophisticated apparatus as by eye detection is feasible and offers the possibility of measuring directly the bioavailable fraction. Bioreporter bacteria are also suitable for in situ research. Yet, in order to apply such bioreporter bacteria as a low-cost analytical tool in a regular manner, open questions exist regarding the preservation of the specific activity, the vitality of bioreporter bacteria and the improvement of bioreporter test systems for layman. The aim of this thesis hence was to optimize and improve bioreporter based test systems to allow easy conservation, storage and transport, and also an application without the need of a sophisticated infrastructure. For that purpose it was intended (i) to develop and validate a method that allows arsenic detection without external calibration (chapter 2) and (ii) to improve the

  9. Improvement of bioreporter bacteria-based test systems for the analysis of arsenic in drinking water and the rhizosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kuppardt, Anke

    2010-02-05

    Contamination of drinking water with arsenic can be measured in laboratories with atom absorption spectrometry (AAS), mass spectrometry with inductive coupled plasma (ICP-MS) or atom fluorescence spectrometry (AFS) at the relevant concentrations below 50 {mu}g/L. Field test kits which easily and reliably measure arsenic concentrations are not yet available. Test systems on the basis of bioreporter bacteria offer an alternative. Based on the natural resistance mechanism of bacteria against arsenic compounds toxic for humans, bioreporter bacteria can be constructed that display arsenic concentrations with light emission (luminescence or fluorescence) or colour reactions. This is achieved by coupling the gene for the ArsR-protein and arsenic regulated promoters with suitable reporter genes. The resulting bioreporter bacteria report bioavailable arsenic in a dose dependent manner at the toxicologically relevant level of 2 to 80 {mu}g/L and are therewith suitable both for the guideline levels of the WHO of 10 {mu}g/L and for the national standards in South East Asia of 50 {mu}g/L. This alternative method has the advantage of being independent from sophisticated apparatus as by eye detection is feasible and offers the possibility of measuring directly the bioavailable fraction. Bioreporter bacteria are also suitable for in situ research. Yet, in order to apply such bioreporter bacteria as a low-cost analytical tool in a regular manner, open questions exist regarding the preservation of the specific activity, the vitality of bioreporter bacteria and the improvement of bioreporter test systems for layman. The aim of this thesis hence was to optimize and improve bioreporter based test systems to allow easy conservation, storage and transport, and also an application without the need of a sophisticated infrastructure. For that purpose it was intended (i) to develop and validate a method that allows arsenic detection without external calibration (chapter 2) and (ii) to

  10. Uptake of Arsenic in Rice Plant Varieties Cultivated with Arsenic Rich Groundwater

    Directory of Open Access Journals (Sweden)

    Piyal Bhattacharya

    2010-07-01

    Full Text Available Groundwater of many areas of West Bengal, India is severely contaminated with arsenic. The paddy soil gets con¬taminated from the groundwater and thus there is a probability of bioaccumulation of arsenic in rice plants cultivated with arsenic contaminated groundwater and soil. This study aims at assessing the level of arsenic in irrigation water and soil and to investigate the seasonal bioaccumulation of arsenic in the various parts (straw, husk and grain of the rice plant of differ¬ent varieties in the arsenic affected two blocks (Chakdaha and Ranaghat-I of Nadia district, West Bengal. It was found that the arsenic uptake in rice during the pre-monsoon season is more than that of the post-monsoon season. The accumulation of arsenic found to vary with different rice varieties; the maximum accumulation was in White minikit (0.31±0.005 mg/kg and IR 50 (0.29±0.001 mg/kg rice varieties and minimum was found to be in the Jaya rice variety (0.14±0.002 mg/kg. In rice plant maximum arsenic accumulation occurred in the straw part (0.89±0.019-1.65±0.021 mg/kg compared to the ac¬cumulation in husk (0.31±0.011-0.85±0.016 mg/kg and grain (0.14±0.002-0.31±0.005 mg/kg parts. For any rice sample concentration of arsenic in the grain did not exceed the WHO recommended permissible limit in rice (1.0 mg/kg.

  11. Mouse Assay for Determination of Arsenic Bioavailability in Contaminated Soils

    Science.gov (United States)

    Background: Accurate assessment of human exposure estimates from arsenic-contaminated soils depends upon estimating arsenic (As) soil bioavailability. Development of bioavailability assays provides data needed for human health risk assessments and supports development and valida...

  12. Arsenic uptake by Lemna minor in hydroponic system.

    Science.gov (United States)

    Goswami, Chandrima; Majumder, Arunabha; Misra, Amal Kanti; Bandyopadhyay, Kaushik

    2014-01-01

    Arsenic is hazardous and causes several ill effects on human beings. Phytoremediation is the use of aquatic plants for the removal of toxic pollutants from external media. In the present research work, the removal efficiency as well as the arsenic uptake capacity of duckweed Lemna minor has been studied. Arsenic concentration in water samples and plant biomass were determined by AAS. The relative growth factor of Lemna minor was determined. The duckweed had potential to remove as well as uptake arsenic from the aqueous medium. Maximum removal of more than 70% arsenic was achieved atinitial concentration of 0.5 mg/1 arsenic on 15th day of experimental period of 22 days. Removal percentage was found to decrease with the increase in initial concentration. From BCF value, Lemna minor was found to be a hyperaccumulator of arsenic at initial concentration of 0.5 mg/L, such that accumulation decreased with increase in initial arsenic concentration. PMID:24933913

  13. Arsenic and the Epigenome: Linked by Methylation(SOT)

    Science.gov (United States)

    Inorganic arsenic (iAs) is an environmental toxicant currently poisoning millions of people worldwide, and chronically-exposed individuals are susceptible to arsenic poisoning, or arsenicosis. In some exposed populations arsenicosis susceptibility is dependent in part on the abil...

  14. Map of Arsenic concentrations in groundwater of the United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The map graphic image at http://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about...

  15. Effects of microbially induced transformations and shift in bacterial community on arsenic mobility in arsenic-rich deep aquifer sediments.

    Science.gov (United States)

    Das, Suvendu; Liu, Chia-Chuan; Jean, Jiin-Shuh; Lee, Chuan-Chun; Yang, Huai-Jen

    2016-06-01

    Elevated concentration of arsenic (As) prevailed in deep aquifers of Chianan Plain, Taiwan. Arsenic release in relation to microbially induced transformations and shift in bacterial communities in deep aquifer sediments of Budai, southwestern Taiwan were investigated using microcosm experiments and substrate amendments over 90 days of anaerobic incubation. The results revealed that As reduction was independent of Fe reduction and a modest rate of sedimentary As release into aqueous phase occurred at the expense of the native organic carbon. Addition of lactate resulted in a parallel increase in As(III) (3.7-fold), Fe(II) (6.2-fold) and Mn (3.5 fold) in aqueous phase compared to un-amended slurries and the enrichment of sequences related to mostly Bacillus, Flavisolibacter, and Geobacter spp, suggesting the important role of these bacteria in As enrichment through reductive dissolution of As-bearing Fe and Mn minerals. The increase in phosphate-extractable As in solid phase with concomitant rise in As in aqueous phase over the course of incubation further attested to the importance of reductive dissolution in promoting As release. Furthermore, the increase in arrA gene abundance with addition of labile carbon suggests that dissimilatory As reduction also may contribute to As enrichment in the water of the deep aquifer of Budai. PMID:26897570

  16. Reduction, methylation, and translocation of arsenic in Panax notoginseng grown under field conditions in arsenic-contaminated soils.

    Science.gov (United States)

    Ma, Jie; Mi, Yanhua; Li, Qiwan; Chen, Lu; Du, Lijuan; He, Lizhong; Lei, Mei

    2016-04-15

    Variations in arsenic (As) species in Panax notoginseng grown under field conditions remain understudied compared with those under greenhouse conditions. In the present study, soil and plant samples were collected from Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, which is the main production area of P. notoginseng in China, to identify As species in the soil and plant tissues and further assess effect of As toxic stress on As transformation and translocation in P. notoginseng. The results showed that arsenate (As(V)) was almost exclusively identified in the soil, while arsenite (As(III)) and monomethylarsonic acid (MMA) were detected in high proportions in plant tissues, suggesting that As(V) could be reduced and subsequently methylated in the plant body, mainly in the root. The reduction and methylation of As in the root of P. notoginseng were promoted by low As toxic stress, but were impeded by high As toxic stress. Arsenic(III) and MMA could rapidly translocate upwards in P. notoginseng. In addition, the translocation of total As, As(III), and MMA from the root to the rhizome was a response to As toxic stress, and the translocation rate increased with the increasing As concentration in the taproot. This study provides new insights into the detoxification mechanism of P. notoginseng grown in As-contaminated soils and the control of As during cultivation. PMID:26851761

  17. Arsenic

    Science.gov (United States)

    ... may also expose normal cells in a lab dish to the substance to see if it causes ... www.cancer.org . Known and Probable Human Carcinogens National organizations and websites Along with the American Cancer ...

  18. Accumulation and transport mechanisms of arsenic in rice

    OpenAIRE

    Islam, Md. Rafiqul; Kamiya, Takehiro; Uraguchi, Shimpei; Fujiwara, Toru

    2009-01-01

    Both species of arsenic (As), arsenate and arsenite are highly toxic to plants. Arsenic contamination is a major problem in Southeast Asia particularly in Bangladesh and West Bengal. In these countries, As-contaminated groundwater is widely used for irrigating rice in dry season that results in elevated As accumulation in soils and in rice grain and straw. So it is important for understanding the accumulation and transport mechanisms of arsenic in rice. We monitored increased arsenic content ...

  19. Environmental arsenic exposure and serum matrix metalloproteinase-9

    OpenAIRE

    Burgess, Jefferey L.; Kurzius-Spencer, Margaret; O’Rourke, Mary Kay; Littau, Sally R.; Roberge, Jason; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Harris, Robin B

    2012-01-01

    The objective of this study was to evaluate the relationship between environmental arsenic exposure and serum matrix metalloproteinase (MMP)-9, a biomarker associated with cardiovascular disease and cancer. In a cross-sectional study of residents of Arizona, USA (n=215) and Sonora, Mexico (n=163), drinking water was assayed for total arsenic, and daily drinking water arsenic intake estimated. Urine was speciated for arsenic and concentrations were adjusted for specific gravity. Serum was anal...

  20. Effect of drinking arsenic-contaminated water in children

    OpenAIRE

    Majumdar, Kunal K.; Guha Mazumder, D.N.

    2012-01-01

    Chronic arsenic toxicity due to drinking of arsenic-contaminated water has been a major environmental health hazard throughout the world including India. Although a lot of information is available on health effects due to chronic arsenic toxicity in adults, knowledge of such effect on children is scanty. A review of the available literature has been made to highlight the problem in children. Scientific publications on health effects of chronic arsenic toxicity in children with special referen...

  1. Arsenic removal in drinking water by reverse osmosis

    OpenAIRE

    Ahmad, Md. Fayej

    2012-01-01

    Arsenic is widely distributed in nature in the air, water and soil. Acute and chronic arsenic exposure by drinking water has been reported in many countries, especially Argentina, Bangladesh, India, Mexico, Mongolia, Thailand and Taiwan. There are many techniques used to remove arsenic from drinking water. Among them reverse osmosis is widely used. Therefore the purpose of this study is to find the conditions favorable for removal of arsenic from drinking water by using reverse osmosis ...

  2. Gut Microbiome Phenotypes Driven by Host Genetics Affect Arsenic Metabolism

    OpenAIRE

    Lu, Kun; Mahbub, Ridwan; Cable, Peter Hans; Ru, Hongyu; Parry, Nicola M. A.; Bodnar, Wanda M.; Wishnok, John S.; Styblo, Miroslav; Swenberg, James A.; Fox, James G; Tannenbaum, Steven R.

    2014-01-01

    Large individual differences in susceptibility to arsenic-induced diseases are well-documented and frequently associated with different patterns of arsenic metabolism. In this context, the role of the gut microbiome in directly metabolizing arsenic and triggering systemic responses in diverse organs raises the possibility that gut microbiome phenotypes affect the spectrum of metabolized arsenic species. However, it remains unclear how host genetics and the gut microbiome interact to affect th...

  3. Removal of arsenic and COD from industrial wastewaters by electrocoagulation

    OpenAIRE

    H. POIROT; Michon, C.; O. POTIE; S. ZOD; Valentin, G.; Leclerc, J.P.; F. LAPICQU

    2011-01-01

    The paper deals with the treatment of arsenic-containing industrial wastewaters by electrocoagulation. The waste issued from a paper mill industry downstream of the biological treatment by activated sludge was enriched with arsenic salts for the purpose of investigation of the treatment of mixed pollution. First, the treatment of single polluted waters, i.e. containing either the regular organic charge from the industrial waste or arsenic salts only, was studied. In the case of arsenic-contai...

  4. Arsenic on the Hands of Children after Playing in Playgrounds

    OpenAIRE

    Kwon, Elena; Zhang, Hongquan; Wang, Zhongwen; Jhangri, Gian S; Lu, Xiufen; Fok, Nelson; Gabos, Stephan; Li, Xing-Fang; Le, X. Chris

    2004-01-01

    Increasing concerns over the use of wood treated with chromated copper arsenate (CCA) in playground structures arise from potential exposure to arsenic of children playing in these playgrounds. Limited data from previous studies analyzing arsenic levels in sand samples collected from CCA playgrounds are inconsistent and cannot be directly translated to the amount of children’s exposure to arsenic. The objective of this study was to determine the quantitative amounts of arsenic on the hands of...

  5. Arsenic-related Bowen's disease, palmar keratosis, and skin cancer.

    OpenAIRE

    Cöl, M; Cöl, C; Soran, A; Sayli, B S; Oztürk, S

    1999-01-01

    Chronic arsenical intoxication can still be found in environmental and industrial settings. Symptoms of chronic arsenic intoxication include general pigmentation or focal "raindrop" pigmentation of the skin and the appearance of hyperkeratosis of the palms of the hands and soles of the feet. In addition to arsenic-related skin diseases including keratosis, Bowen's disease, basal-cell-carcinoma, and squamous-cell carcinoma, there is also an increased risk of some internal malignancies. Arsenic...

  6. Overexpression of cell cycle regulator CDCA3 promotes oral cancer progression by enhancing cell proliferation with prevention of G1 phase arrest

    International Nuclear Information System (INIS)

    Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC. We evaluated CDCA3 mRNA and protein expression in both OSCC-derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system. The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p < 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p < 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21Cip1, p27Kip1, p15INK4B, and p16INK4A) in the knockdown cells. The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors

  7. TSH overcomes Braf(V600E)-induced senescence to promote tumor progression via downregulation of p53 expression in papillary thyroid cancer.

    Science.gov (United States)

    Zou, M; Baitei, E Y; Al-Rijjal, R A; Parhar, R S; Al-Mohanna, F A; Kimura, S; Pritchard, C; Binessa, H A; Alzahrani, A S; Al-Khalaf, H H; Hawwari, A; Akhtar, M; Assiri, A M; Meyer, B F; Shi, Y

    2016-04-14

    The BRAF(V600E) mutation is found in approximately 40% of papillary thyroid cancers (PTC). Mice with thyroid-specific expression of Braf(V600E) (TPO-Braf(V600E)) develop PTC rapidly with high levels of serum thyroid-stimulating hormone (TSH). It is unclear to what extent the elevated TSH contributes to tumor progression. To investigate the progression of Braf(V600E)-induced PTC (BVE-PTC) under normal TSH, we transplanted BVE-PTC tumors subcutaneously into nude and TPO-Braf(WT) mice. Regression of the transplanted tumors was observed in both nude and TPO-Braf(WT) mice. They were surrounded by heavy lymphocyte infiltration and oncogene-induced senescence (OIS) was demonstrated by strong β-gal staining and absence of Ki-67 expression. In contrast, BVE-PTC transplants continued to grow when transplanted into TPO-Braf(V600E) mice. The expression of Trp53 was increased in tumor transplants undergoing OIS. Trp53 inactivation reversed OIS and enabled tumor transplants to grow in nude mice with characteristic cell morphology of anaplastic thyroid cancer (ATC). PTC-to-ATC transformation was also observed in primary BVE-PTC tumors. ATC cells derived from Trp53 knockout tumors had increased PI3K/AKT signaling and became resistant to Braf(V600E) inhibitor PLX4720, which could be overcome by combined treatment of PI3K inhibitor LY294002 and PLX4720. In conclusion, BVE-PTC progression could be contained via p53-dependent OIS and TSH is a major disruptor of this balance. Simultaneous targeting of both MAPK and PI3K/AKT pathways offer a better therapeutic outcome against ATC. The current study reinforces the importance of rigorous control of serum TSH in PTC patients. PMID:26477313

  8. Dissolved Air Flotation of arsenic adsorbent particles

    Directory of Open Access Journals (Sweden)

    M. Santander

    2015-04-01

    Full Text Available The removal of arsenic from synthetic effluent was studied using the adsorbent particle flotation technique (APF and dissolved air flotation (DAF. A sample of an iron mineral was used as adsorbent particles of arsenic, ferric chloride as coagulant, cationic polyacrylamide (NALCO 9808 as flocculants, and sodium oleate as collector. Adsorption studies to determine the pH influence, contact time, and adsorbent particles concentration on the adsorption of arsenic were carried out along with flotation studies to determine the removal efficiency of adsorbents particles. The results achieved indicate that the adsorption kinetic of arsenic is very rapid and that in range of pH’s from 2 to 7 the adsorption percentages remain constant. The equilibrium conditions were achieved in 60 minutes and about 95% of arsenic was adsorbed when used an adsorbent concentration of 2 g/L and pH 6.3. The maximum adsorption capacity of adsorbent particles was 4.96 mg/g. The mean free energy of adsorption (E was found to be 2.63 kJ/mol, which suggests physisorption. The results of the flotation studies demonstrated that when synthetic effluents with 8.9 mg/L of arsenic were treated under the following experimental conditions; 2 g/L of adsorbent particles, 120 mg/L of Fe(III, 2 mg/L of Nalco 9808, 20 mg/L of sodium oleate, and 40% of recycle ratio in the DAF, it was possible to reach 98% of arsenic removal and 6.3 NTU of residual turbidity in clarified synthetic effluent.

  9. Arsenic management through well modification and simulation.

    Science.gov (United States)

    Halford, Keith J; Stamos, Christina L; Nishikawa, Tracy; Martin, Peter

    2010-01-01

    Arsenic concentrations can be managed with a relatively simple strategy of grouting instead of completely destroying a selected interval of well. The strategy of selective grouting was investigated in Antelope Valley, California, where groundwater supplies most of the water demand. Naturally occurring arsenic typically exceeds concentrations of 10 microg/L in the water produced from these long-screened wells. The vertical distributions of arsenic concentrations in intervals of the aquifer contributing water to selected supply wells were characterized with depth-dependent water-quality sampling and flow logs. Arsenic primarily entered the lower half of the wells where lacustrine clay deposits and a deeper aquifer occurred. Five wells were modified by grouting from below the top of the lacustrine clay deposits to the bottom of the well, which reduced produced arsenic concentrations to less than 2 microg/L in four of the five wells. Long-term viability of well modification and reduction of specific capacity was assessed for well 4-54 with AnalyzeHOLE, which creates and uses axisymmetric, radial MODFLOW models. Two radial models were calibrated to observed borehole flows, drawdowns, and transmissivity by estimating hydraulic-conductivity values in the aquifer system and gravel packs of the original and modified wells. Lithology also constrained hydraulic-conductivity estimates as regularization observations. Well encrustations caused as much as 2 microg/L increase in simulated arsenic concentration by reducing the contribution of flow from the aquifer system above the lacustrine clay deposits. Simulated arsenic concentrations in the modified well remained less than 3 microg/L over a 20-year period. PMID:20113363

  10. Arsenic management through well modification and simulation

    Science.gov (United States)

    Halford, Keith J.; Stamos, Christina L.; Nishikawa, Tracy; Martin, Peter

    2010-01-01

    Arsenic concentrations can be managed with a relatively simple strategy of grouting instead of completely destroying a selected interval of well. The strategy of selective grouting was investigated in Antelope Valley, California, where groundwater supplies most of the water demand. Naturally occurring arsenic typically exceeds concentrations of 10 (mu or u)g/L in the water produced from these long-screened wells. The vertical distributions of arsenic concentrations in intervals of the aquifer contributing water to selected supply wells were characterized with depth-dependent water-quality sampling and flow logs. Arsenic primarily entered the lower half of the wells where lacustrine clay deposits and a deeper aquifer occurred. Five wells were modified by grouting from below the top of the lacustrine clay deposits to the bottom of the well, which reduced produced arsenic concentrations to less than 2 (mu or u)g/L in four of the five wells. Long-term viability of well modification and reduction of specific capacity was assessed for well 4-54 with AnalyzeHOLE, which creates and uses axisymmetric, radial MODFLOW models. Two radial models were calibrated to observed borehole flows, drawdowns, and transmissivity by estimating hydraulicconductivity values in the aquifer system and gravel packs of the original and modified wells. Lithology also constrained hydraulic-conductivity estimates as regularization observations. Well encrustations caused as much as 2 (mu or u)g/L increase in simulated arsenic concentration by reducing the contribution of flow from the aquifer system above the lacustrine clay deposits. Simulated arsenic concentrations in the modified well remained less than 3 (mu or u)g/L over a 20-year period.

  11. Akt/Protein Kinase B-Dependent Phosphorylation and Inactivation of WEE1Hu Promote Cell Cycle Progression at G2/M Transition

    OpenAIRE

    Katayama, Kazuhiro; Fujita, Naoya; Tsuruo, Takashi

    2005-01-01

    The serine/threonine kinase Akt is known to promote cell growth by regulating the cell cycle in G1 phase through activation of cyclin/Cdk kinases and inactivation of Cdk inhibitors. However, how the G2/M phase is regulated by Akt remains unclear. Here, we show that Akt counteracts the function of WEE1Hu. Inactivation of Akt by chemotherapeutic drugs or the phosphatidylinositide-3-OH kinase inhibitor LY294002 induced G2/M arrest together with the inhibitory phosphorylation of Cdc2. Because the...

  12. TRACE ANALYSIS OF ARSENIC BY COLORIMETRY, ATOMIC ABSORPTION, AND POLAROGRAPHY

    Science.gov (United States)

    A differential pulse polarographic method was developed for determining total arsenic concentrations in water samples from ash ponds at steam-electric generating plants. After digestion of the sample and isolation of arsenic by solvent extraction, the peak current for arsenic is ...

  13. Population Based Exposure Assessment of Bioaccessible Arsenic in Carrots

    Science.gov (United States)

    The two predominant arsenic exposure routes are food and water. Estimating the risk from dietary exposures is complicated, owing to the chemical form dependent toxicity of arsenic and the diversity of arsenicals present in dietary matrices. Two aspects of assessing dietary expo...

  14. Tumour-initiating cell-specific miR-1246 and miR-1290 expression converge to promote non-small cell lung cancer progression

    Science.gov (United States)

    Zhang, Wen Cai; Chin, Tan Min; Yang, Henry; Nga, Min En; Lunny, Declan Patrick; Lim, Edwin Kok Hao; Sun, Li Li; Pang, Yin Huei; Leow, Yi Ning; Malusay, Shanneen Rossellini Y; Lim, Priscilla Xin Hui; Lee, Jeravan Zili; Tan, Benedict Jian Wei; Shyh-Chang, Ng; Lim, Elaine Hsuen; Lim, Wan Teck; Tan, Daniel Shao Weng; Tan, Eng Huat; Tai, Bee Choo; Soo, Ross Andrew; Tam, Wai Leong; Lim, Bing

    2016-01-01

    The tumour-initiating cell (TIC) model accounts for phenotypic and functional heterogeneity among tumour cells. MicroRNAs (miRNAs) are regulatory molecules frequently aberrantly expressed in cancers, and may contribute towards tumour heterogeneity and TIC behaviour. More recent efforts have focused on miRNAs as diagnostic or therapeutic targets. Here, we identified the TIC-specific miRNAs, miR-1246 and miR-1290, as crucial drivers for tumour initiation and cancer progression in human non-small cell lung cancer. The loss of either miRNA impacted the tumour-initiating potential of TICs and their ability to metastasize. Longitudinal analyses of serum miR-1246 and miR-1290 levels across time correlate their circulating levels to the clinical response of lung cancer patients who were receiving ongoing anti-neoplastic therapies. Functionally, direct inhibition of either miRNA with locked nucleic acid administered systemically, can arrest the growth of established patient-derived xenograft tumours, thus indicating that these miRNAs are clinically useful as biomarkers for tracking disease progression and as therapeutic targets. PMID:27325363

  15. Human Arsenic Poisoning Issues in Central-East Indian Locations: Biomarkers and Biochemical Monitoring

    OpenAIRE

    Madhurima Pandey; Sushma Yadav; Piyush Kant Pandey

    2007-01-01

    The study reports the use of three biomarkers i.e. total arsenic in hair and nails, total arsenic in blood, and total arsenic in urine to identify or quantify arsenic exposure and concomitant health effects. The main source of arsenic was inorganic exposure through drinking water. The arsenic levels and the health effects were analyzed closely in a family having maximum symptoms of arsenic. Based on the result of this study it is reported that there exist a correlation between the clinically ...

  16. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    International Nuclear Information System (INIS)

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As2O3

  17. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Stueckle, Todd A., E-mail: tstueckle@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Lu, Yongju, E-mail: yongju6@hotmail.com [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Davis, Mary E., E-mail: mdavis@wvu.edu [Department of Physiology, West Virginia University, Morgantown, WV 26506 (United States); Wang, Liying, E-mail: lmw6@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Jiang, Bing-Hua, E-mail: bhjiang@jefferson.edu [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Holaskova, Ida, E-mail: iholaskova@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Schafer, Rosana, E-mail: rschafer@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Barnett, John B., E-mail: jbarnett@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Rojanasakul, Yon, E-mail: yrojan@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States)

    2012-06-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As{sub 2}O

  18. TERT启动子突变在甲状腺癌中的研究进展%Research progress of TERT promoter mutation in thyroid carcinoma

    Institute of Scientific and Technical Information of China (English)

    殷德涛; 余坤

    2015-01-01

    甲状腺癌是内分泌系统最常见的恶性肿瘤,近年来发现端粒酶逆转录酶启动子突变可使细胞端粒不缩短,从而使细胞永生化,在甲状腺癌的发生发展和浸润转移中发挥了重要作用.端粒酶逆转录酶启动子突变对甲状腺癌的诊断和预后判断有重要的价值,术前检测端粒酶逆转录酶启动子突变能有效指导甲状腺癌治疗方案的选择.%Thyroid carcinoma is the most frequent endocrine cancer.Recently, it has been discovered that telomerase reverse transcriptase promoter mutation can prevent cell tolemeres from shortening, leading to cell immortalization and plays an important role in the tumor genesis, invasiveness and metastasis of the thyroid carcinoma.Testing of telomerase reverse transcriptase promoter mutation is of great value in diagnosis, which also can be used as a prognostic maker of thyroid carcinoma.

  19. Identification of arsenic resistant endophytic bacteria from Pteris vittata roots and characterization for arsenic remediation application.

    Science.gov (United States)

    Tiwari, Sarita; Sarangi, Bijaya Ketan; Thul, Sanjog T

    2016-09-15

    Mitigation of arsenic (As) pollution is a topical environmental issue of high R&D priority. The present investigation was carried out to isolate As resistant endophytes from the roots of Indian ecotype Pteris vittata and characterize their As transformation and tolerance ability, plant growth promoting characteristics and their role to facilitate As uptake by the plant. A total of 8 root endophytes were isolated from plants grown in As amended soil (25 mg As kg(-1)). These isolates were studied for minimum inhibitory concentration (MIC), arsenite As(III) - arsenate As(V) transformation ability, plant growth promoting (PGP) characteristics through siderophore, indole acetic acid (IAA) production, phosphatase, ACC deaminase activity, and presence of arsenite oxidase (aox) and arsenite transporter (arsB) genes. On the basis of 16S rDNA sequence analysis, these isolates belong to Proteobacteria, Firmicutes and Bacteroidetes families under the genera Bacillus, Enterobacter, Stenotrophomonas and Rhizobium. All isolates were found As tolerant, of which one isolates showed highest tolerance up to 1000 mg L(-1) concentration in SLP medium. Five isolates were IAA positive with highest IAA production up to 60 mg/L and two isolates exhibited siderophore activity. Phosphatase activity was shown by only one isolate while ACC deaminase activity was absent in all the isolates. The As transformation study by silver nitrate test showed that only two strains had dual characteristics of As(III) oxidation and As (V) reduction, four strains exhibited either of the characteristics while other two didn't confirmed any of the two characteristics. Presence of aox gene was detected in two strains and arsB gene in six isolates. The strain with highest As tolerance also showed highest IAA production and occurrence of arsB gene. Present investigation may open up further scope of utilizing these endophytes for up gradation of phytoextraction process. PMID:27257820

  20. In situ chemical fixation of arsenic-contaminated soils: Anexperimental study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li; Donahoe, Rona J.; Redwine, James C.

    2007-03-27

    This paper reports the results of an experimentalstudytesting a low-cost in situ chemical fixation method designed to reclaimarsenic-contaminated subsurface soils. Subsurface soils from severalindustrial sites in southeastern U.S. were contaminated with arsenicthrough heavy application of herbicide containing arsenic trioxide. Themean concentrations of environmentally available arsenic in soilscollected from the two study sites, FW and BH, are 325 mg/kg and 900mg/kg, respectively. The soils are sandy loams with varying mineralogicaland organic contents. The previous study [Yang L, Donahoe RJ. The form,distribution and mobility of arsenic in soils contaminated by arsenictrioxide, at sites in Southeast USA. Appl Geochem 2007;22:320 341]indicated that a large portion of the arsenic in both soils is associatedwith amorphous aluminum and iron oxyhydroxides and shows very slowrelease against leaching by synthetic precipitation. The soil's amorphousaluminum and iron oxyhydroxides content was found to have the mostsignificant effect on its ability to retain arsenic.Based on thisobservation, contaminated soils were reacted with different treatmentsolutions in an effort to promote the formation of insolublearsenic-bearing phases and thereby decrease the leachability of arsenic.Ferrous sulfate, potassium permanganate and calcium carbonate were usedas the reagents for the chemical fixation solutions evaluated in threesets of batch experiments: (1) FeSO4; (2) FeSO4 and KMnO4; (3) FeSO4,KMnO4 and CaCO3. The optimum treatment solutions for each soil wereidentified based on the mobility of arsenic during sequential leaching oftreated and untreated soils using the fluids described in EPA Method 1311[USEPA. Method 1311: toxicity characteristic leaching procedure. Testmethods for evaluating solid waste, physical/chemical methods. 3rd ed.Washington, DC: U.S. Environmental Protection Agency, Office of SolidWaste. U.S. Government Printing Office; 1992]toxic characteristicsleaching

  1. Well Water Arsenic Exposure, Arsenic Induced Skin-Lesions and Self-Reported Morbidity in Inner Mongolia

    OpenAIRE

    Yajuan Xia; Wade, Timothy J; Kegong Wu; Yanhong Li; Zhixiong Ning; X Chris Le; Binfei Chen; Yong Feng; Mumford, Judy L.; Xingzhou He

    2009-01-01

    Residents of the Bayingnormen region of Inner Mongolia have been exposed to arsenic-contaminated well water for over 20 years, but relatively few studies have investigated health effects in this region. We surveyed one village to document exposure to arsenic and assess the prevalence of arsenic-associated skin lesions and self-reported morbidity. Five-percent (632) of the 12,334 residents surveyed had skin lesions characteristics of arsenic exposure. Skin lesions were strongly associated with...

  2. Chronic Arsenic Poisoning Probably Caused by Arsenic-Based Pesticides: Findings from an Investigation Study of a Household

    OpenAIRE

    Yongfang Li; Feng Ye; Anwei Wang; Da Wang; Boyi Yang; Quanmei Zheng; Guifan Sun; Xinghua Gao

    2016-01-01

    In addition to naturally occurring arsenic, man-made arsenic-based compounds are other sources of arsenic exposure. In 2013, our group identified 12 suspected arsenicosis patients in a household (32 living members). Of them, eight members were diagnosed with skin cancer. Interestingly, all of these patients had lived in the household prior to 1989. An investigation revealed that approximately 2 tons of arsenic-based pesticides had been previously placed near a well that had supplied drinking ...

  3. Roxarsone, Inorganic Arsenic, and Other Arsenic Species in Chicken: A U.S.-Based Market Basket Sample

    OpenAIRE

    Nachman, Keeve E.; Baron, Patrick A; Raber, Georg; Francesconi, Kevin A.; Navas-Acien, Ana; Love, David C.

    2013-01-01

    Background: Inorganic arsenic (iAs) causes cancer and possibly other adverse health outcomes. Arsenic-based drugs are permitted in poultry production; however, the contribution of chicken consumption to iAs intake is unknown. Objectives: We sought to characterize the arsenic species profile in chicken meat and estimate bladder and lung cancer risk associated with consuming chicken produced with arsenic-based drugs. Methods: Conventional, antibiotic-free, and organic chicken samples were colle...

  4. THE PROMOTION OF INNOVATIVE PRODUCTS

    OpenAIRE

    ALYABEDEVA I.

    2012-01-01

    The article aims to consider the issues of the innovative products promotion. Peculiarities of innovative market and its future progress, key factors connected with the promotion of innovative products success are analyzed. Here are also suggested the successful marketing strategies variants of the innovative products promotion.

  5. Carbonate ions and arsenic dissolution by groundwater

    Science.gov (United States)

    Kim, M.-J.; Nriagu, J.; Haack, S.

    2000-01-01

    Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.The role of bicarbonate in leaching arsenic into groundwater was investigated by conducting batch experiments using core samples of Marshall Sandstone from southeast Michigan and different bicarbonate

  6. 砷的地球化学特征与研究方向%Geochemical Characteristics and Research Direction of Arsenic

    Institute of Scientific and Technical Information of China (English)

    伯英; 罗立强

    2009-01-01

    The toxicity of arsenic has been well known since ancient times for the noxious white arsenic. Furthermore, arsenic has been listed in the first group of carcinogens by the Association for International Cancer Research (AICR). Nowadays, millions of individuals in the world are suffering from by arsenic toxicosis and the arsenic contamination has been reported worldwide. The origin of arsenic in environment is rather complex and originated from natural processes(mainly for geological process), or anthropogenic activities, or combination of both. Moreover, arsenic can transfer and transform through different natural geochemical and biological processes,therefore will directly or indirectly harm to people and animals, etc.. In this paper, a comprehensive discussion on arsenic issue is presented, including its origin and distribution, its mobility and transformation, toxicity and impacts on living things, as well as recent progresses on arsenic research. Arsenic contamination and toxicosis in some regions such as Inner Mongolia in China are very serious now, so the research on arsenic geochemistry and impacts on human health from arsenic are tough and meaningful job.%砷的毒性在古代就因砒霜而广为人知,国际癌症研究会将砷列为第一类致癌物.目前,世界上有数以百万计的人受到砷中毒的威胁,砷污染事件在世界范围都有报道.环境中的砷的来源很复杂,有自然因素引起的砷污染(主要是地质成因砷污染),也有人为活动带来的砷污染,还有二者共同作用形成的砷污染.此外,砷还可以通过各种自然的地球化学过程和生物过程进行迁移转化,直接或间接对人和动物等产生危害.文章从砷的来源与分布、砷的毒性和危害、砷的迁移转化、生物在砷循环中作用的新认识等方面进行论述,并针对目前国内外砷污染研究现状,提出在已有研究基础上,建议在河套地区进一步开展砷元素地球化学及人体健康关系研究.

  7. Complementary arsenic speciation methods: A review

    Energy Technology Data Exchange (ETDEWEB)

    Nearing, Michelle M., E-mail: michelle.nearing@rmc.ca; Koch, Iris, E-mail: koch-i@rmc.ca; Reimer, Kenneth J., E-mail: reimer-k@rmc.ca

    2014-09-01

    The toxicity of arsenic greatly depends on its chemical form and oxidation state (speciation) and therefore accurate determination of arsenic speciation is a crucial step in understanding its chemistry and potential risk. High performance liquid chromatography with inductively coupled mass spectrometry (HPLC–ICP-MS) is the most common analysis used for arsenic speciation but it has two major limitations: it relies on an extraction step (usually from a solid sample) that can be incomplete or alter the arsenic compounds; and it provides no structural information, relying on matching sample peaks to standard peaks. The use of additional analytical methods in a complementary manner introduces the ability to address these disadvantages. The use of X-ray absorption spectroscopy (XAS) with HPLC–ICP-MS can be used to identify compounds not extracted for HPLC–ICP-MS and provide minimal processing steps for solid state analysis that may help preserve labile compounds such as those containing arsenic-sulfur bonds, which can degrade under chromatographic conditions. On the other hand, HPLC–ICP-MS is essential in confirming organoarsenic compounds with similar white line energies seen by using XAS, and identifying trace arsenic compounds that are too low to be detected by XAS. The complementary use of electrospray mass spectrometry (ESI–MS) with HPLC–ICP-MS provides confirmation of arsenic compounds identified during the HPLC–ICP-MS analysis, identification of unknown compounds observed during the HPLC–ICP-MS analysis and further resolves HPLC–ICP-MS by identifying co-eluting compounds. In the complementary use of HPLC–ICP-MS and ESI–MS, HPLC–ICP-MS helps to focus the ESI–MS selection of ions. Numerous studies have shown that the information obtained from HPLC–ICP-MS analysis can be greatly enhanced by complementary approaches. - Highlights: • HPLC–ICP-MS is the most common method used for arsenic speciation. • HPLC limitations include

  8. Complementary arsenic speciation methods: A review

    International Nuclear Information System (INIS)

    The toxicity of arsenic greatly depends on its chemical form and oxidation state (speciation) and therefore accurate determination of arsenic speciation is a crucial step in understanding its chemistry and potential risk. High performance liquid chromatography with inductively coupled mass spectrometry (HPLC–ICP-MS) is the most common analysis used for arsenic speciation but it has two major limitations: it relies on an extraction step (usually from a solid sample) that can be incomplete or alter the arsenic compounds; and it provides no structural information, relying on matching sample peaks to standard peaks. The use of additional analytical methods in a complementary manner introduces the ability to address these disadvantages. The use of X-ray absorption spectroscopy (XAS) with HPLC–ICP-MS can be used to identify compounds not extracted for HPLC–ICP-MS and provide minimal processing steps for solid state analysis that may help preserve labile compounds such as those containing arsenic-sulfur bonds, which can degrade under chromatographic conditions. On the other hand, HPLC–ICP-MS is essential in confirming organoarsenic compounds with similar white line energies seen by using XAS, and identifying trace arsenic compounds that are too low to be detected by XAS. The complementary use of electrospray mass spectrometry (ESI–MS) with HPLC–ICP-MS provides confirmation of arsenic compounds identified during the HPLC–ICP-MS analysis, identification of unknown compounds observed during the HPLC–ICP-MS analysis and further resolves HPLC–ICP-MS by identifying co-eluting compounds. In the complementary use of HPLC–ICP-MS and ESI–MS, HPLC–ICP-MS helps to focus the ESI–MS selection of ions. Numerous studies have shown that the information obtained from HPLC–ICP-MS analysis can be greatly enhanced by complementary approaches. - Highlights: • HPLC–ICP-MS is the most common method used for arsenic speciation. • HPLC limitations include

  9. Downregulation of microRNA-362-3p and microRNA-329 promotes tumor progression in human breast cancer.

    Science.gov (United States)

    Kang, H; Kim, C; Lee, H; Rho, J G; Seo, J-W; Nam, J-W; Song, W K; Nam, S W; Kim, W; Lee, E K

    2016-03-01

    p130Cas regulates cancer progression by driving tyrosine receptor kinase signaling. Tight regulation of p130Cas expression is necessary for survival, apoptosis, and maintenance of cell motility in various cell types. Several studies revealed that transcriptional and post-translational control of p130Cas are important for maintenance of its expression and activity. To explore novel regulatory mechanisms of p130Cas expression, we studied the effect of microRNAs (miRs) on p130Cas expression in human breast cancer MCF7 cells. Here, we provide experimental evidence that miR-362-3p and miR-329 perform a tumor-suppressive function and their expression is downregulated in human breast cancer. miR-362-3p and miR-329 inhibited cellular proliferation, migration, and invasion, thereby suppressing tumor growth, by downregulating p130Cas. Ectopic expression of p130Cas attenuated the inhibitory effects of the two miRs on tumor progression. Relative expression levels of miR-362-3p/329 and p130Cas between normal and breast cancer correlated inversely; miR-362-3p/329 expression was decreased, whereas that of p130Cas increased in breast cancers. Furthermore, we showed that downregulation of miR-362-3p and miR-329 was caused by differential DNA methylation of miR genes. Enhanced DNA methylation (according to methylation-specific PCR) was responsible for downregulation of miR-362-3p and miR-329 in breast cancer. Taken together, these findings point to a novel role for miR-362-3p and miR-329 as tumor suppressors; the miR-362-3p/miR-329-p130Cas axis seemingly has a crucial role in breast cancer progression. Thus, modulation of miR-362-3p/miR-329 may be a novel therapeutic strategy against breast cancer. PMID:26337669

  10. Purification and characterization of thiols in an arsenic hyperaccumulator under arsenic exposure.

    Science.gov (United States)

    Zhang, Weihua; Cai, Yong

    2003-12-15

    Pteris vittata (Chinese brake fern) is the first reported arsenic hyperaccumulator. To investigate the arsenic tolerance mechanism in this plant, reversed-phase HPLC with postcolumn derivatization was used to analyze the thiols induced under arsenic exposure. A major thiol in the plant leaflets was found to be responsive to arsenic exposure. The arsenic-induced compound was purified on a large scale by combining covalent chromatography and preparative reversed-phase HPLC. About 2 mg of this compound was isolated from 1 kg of fresh leaflets. The purified arsenic-induced compound was characterized using electrospray ionization mass spectrometry. A molecular ion (M + 1) of 540 and fragments were obtained, which indicated that the arsenic-induced thiol was a phytochelatin with two subunits (PC(2)). Compared to the classical methods for purification of phytochelatins, this new method is more specific, simple, and rapid and is suitable for purification of PCs in a large scale as well as sample preparation for mass spectrometry analysis. PMID:14670068

  11. Chronic Arsenic Poisoning Probably Caused by Arsenic-Based Pesticides: Findings from an Investigation Study of a Household

    Directory of Open Access Journals (Sweden)

    Yongfang Li

    2016-01-01

    Full Text Available In addition to naturally occurring arsenic, man-made arsenic-based compounds are other sources of arsenic exposure. In 2013, our group identified 12 suspected arsenicosis patients in a household (32 living members. Of them, eight members were diagnosed with skin cancer. Interestingly, all of these patients had lived in the household prior to 1989. An investigation revealed that approximately 2 tons of arsenic-based pesticides had been previously placed near a well that had supplied drinking water to the family from 1973 to 1989. The current arsenic level in the well water was 620 μg/L. No other high arsenic wells were found near the family’s residence. Based on these findings, it is possible to infer that the skin lesions exhibited by these family members were caused by long-term exposure to well water contaminated with arsenic-based pesticides. Additionally, biochemical analysis showed that the individuals exposed to arsenic had higher levels of aspartate aminotransferase and γ-glutamyl transpeptidase than those who were not exposed. These findings might indicate the presence of liver dysfunction in the arsenic-exposed individuals. This report elucidates the effects of arsenical compounds on the occurrence of high levels of arsenic in the environment and emphasizes the severe human health impact of arsenic exposure.

  12. Comparative Distribution and Retention of Arsenic in Arsenic (+3 Oxidation State) Methyltransferase Knockout and Wild Type Mice

    Science.gov (United States)

    The mouse arsenic (+3 oxidation state) methyltransferase (As3mt) gene encodes a ~ 43 kDa protein that catalyzes conversion of inorganic arsenic into methylated products. Heterologous expression of AS3MT or its silencing by RNA interference controls arsenic methylation phenotypes...

  13. Non-coding RNA LINC00857 is predictive of poor patient survival and promotes tumor progression via cell cycle regulation in lung cancer

    Science.gov (United States)

    Wang, Lihui; He, Yanli; Liu, Weijun; Bai, Shengbin; Xiao, Lei; Zhang, Jie; Dhanasekaran, Saravana M.; Wang, Zhuwen; Kalyana-Sundaram, Shanker; Balbin, O. Alejandro; Shukla, Sudhanshu; Lu, Yi; Lin, Jules; Reddy, Rishindra M.; Carrott, Philip W.; Lynch, William R.; Chang, Andrew C.; Chinnaiyan, Arul M.; Beer, David G.; Zhang, Jian; Chen, Guoan

    2016-01-01

    We employed next generation RNA sequencing analysis to reveal dysregulated long non-coding RNAs (lncRNAs) in lung cancer utilizing 461 lung adenocarcinomas (LUAD) and 156 normal lung tissues from 3 separate institutions. We identified 281 lncRNAs with significant differential-expression between LUAD and normal lung tissue. LINC00857, a top deregulated lncRNAs, was overexpressed in tumors and significantly associated with poor survival in LUAD. knockdown of LINC00857 with siRNAs decreased tumor cell proliferation, colony formation, migration and invasion in vitro, as well as tumor growth in vivo. Overexpression of LINC00857 increased cancer cell proliferation, colony formation and invasion. Mechanistic analyses indicated that LINC00857 mediates tumor progression via cell cycle regulation. Our study highlights the diagnostic/prognostic potential of LINC00857 in LUAD besides delineating the functional and mechanistic aspects of its aberrant disease specific expression and potentially using as a new therapeutic target. PMID:26862852

  14. Non-coding RNA LINC00857 is predictive of poor patient survival and promotes tumor progression via cell cycle regulation in lung cancer.

    Science.gov (United States)

    Wang, Lihui; He, Yanli; Liu, Weijun; Bai, Shengbin; Xiao, Lei; Zhang, Jie; Dhanasekaran, Saravana M; Wang, Zhuwen; Kalyana-Sundaram, Shanker; Balbin, O Alejandro; Shukla, Sudhanshu; Lu, Yi; Lin, Jules; Reddy, Rishindra M; Carrott, Philip W; Lynch, William R; Chang, Andrew C; Chinnaiyan, Arul M; Beer, David G; Zhang, Jian; Chen, Guoan

    2016-03-01

    We employed next generation RNA sequencing analysis to reveal dysregulated long non-coding RNAs (lncRNAs) in lung cancer utilizing 461 lung adenocarcinomas (LUAD) and 156 normal lung tissues from 3 separate institutions. We identified 281 lncRNAs with significant differential-expression between LUAD and normal lung tissue. LINC00857, a top deregulated lncRNAs, was overexpressed in tumors and significantly associated with poor survival in LUAD. knockdown of LINC00857 with siRNAs decreased tumor cell proliferation, colony formation, migration and invasion in vitro, as well as tumor growth in vivo. Overexpression of LINC00857 increased cancer cell proliferation, colony formation and invasion. Mechanistic analyses indicated that LINC00857 mediates tumor progression via cell cycle regulation. Our study highlights the diagnostic/prognostic potential of LINC00857 in LUAD besides delineating the functional and mechanistic aspects of its aberrant disease specific expression and potentially using as a new therapeutic target. PMID:26862852

  15. DNA Hypomethylation and Histone Variant macroH2A1 Synergistically Attenuate Chemotherapy-Induced Senescence to Promote Hepatocellular Carcinoma Progression.

    Science.gov (United States)

    Borghesan, Michela; Fusilli, Caterina; Rappa, Francesca; Panebianco, Concetta; Rizzo, Giovanni; Oben, Jude A; Mazzoccoli, Gianluigi; Faulkes, Chris; Pata, Illar; Agodi, Antonella; Rezaee, Farhad; Minogue, Shane; Warren, Alessandra; Peterson, Abigail; Sedivy, John M; Douet, Julien; Buschbeck, Marcus; Cappello, Francesco; Mazza, Tommaso; Pazienza, Valerio; Vinciguerra, Manlio

    2016-02-01

    Aging is a major risk factor for progression of liver diseases to hepatocellular carcinoma (HCC). Cellular senescence contributes to age-related tissue dysfunction, but the epigenetic basis underlying drug-induced senescence remains unclear. macroH2A1, a variant of histone H2A, is a marker of senescence-associated heterochromatic foci that synergizes with DNA methylation to silence tumor-suppressor genes in human fibroblasts. In this study, we investigated the relationship between macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, and liver carcinogenesis. We found that protein levels of both macroH2A1 isoforms were increased in the livers of very elderly rodents and humans, and were robust immunohistochemical markers of human cirrhosis and HCC. In response to the chemotherapeutic and DNA-demethylating agent 5-aza-deoxycytidine (5-aza-dC), transgenic expression of macroH2A1 isoforms in HCC cell lines prevented the emergence of a senescent-like phenotype and induced synergistic global DNA hypomethylation. Conversely, macroH2A1 depletion amplified the antiproliferative effects of 5-aza-dC in HCC cells, but failed to enhance senescence. Senescence-associated secretory phenotype and whole-transcriptome analyses implicated the p38 MAPK/IL8 pathway in mediating macroH2A1-dependent escape of HCC cells from chemotherapy-induced senescence. Furthermore, chromatin immunoprecipitation sequencing revealed that this hepatic antisenescence state also required active transcription that could not be attributed to genomic occupancy of these histones. Collectively, our findings reveal a new mechanism by which drug-induced senescence is epigenetically regulated by macroH2A1 and DNA methylation and suggest macroH2A1 as a novel biomarker of hepatic senescence that could potentially predict prognosis and disease progression. PMID:26772755

  16. Arsenic Speciation in Blue Mussels (Mytilus edulis) Along a Highly Contaminated Arsenic Gradient

    Energy Technology Data Exchange (ETDEWEB)

    Whaley-Martin, K.J.; Koch, I.; Moriarty, M.; Reimer, K.J. (Royal)

    2012-11-01

    Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strong arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As-C bonds) and total arsenic concentrations present in M. edulis tissues (R{sup 2} = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R{sup 2} = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic-sulfur compounds. The XAS mapping revealed that the As(III)-S and/or As(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel's cells in a physiological function such as an intracellular osmolyte.

  17. Research progress on intervention method of promoting benefit finding%提升益处发现的干预方法研究进展

    Institute of Scientific and Technical Information of China (English)

    邵丽华

    2015-01-01

    There were many intervention methods that mainly included cognitive behavior management,stress management,peer support,complementary and alternative medicine and positive reflection to promote benefit finding.The intervention obj ects mainly focused on patients with breast cancer or alzheimer’s disease or AIDS. It put forward that the study on benefit finding was still in the stage of exploration.%提高益处发现的干预方法主要有认知行为管理、压力管理、同伴支持、补充和替代疗法、积极反思等方法,干预对象主要集中于乳腺癌、阿尔兹海默病、艾滋病病人等。提出益处发现的研究尚处于探索阶段。

  18. 土壤中植物根际促生菌研究进展%Research Progress of Plant Growth-promoting Rhizobacteria in Soil

    Institute of Scientific and Technical Information of China (English)

    李海宗; 潘梅

    2014-01-01

    植物根际促生菌(Plant growth-promoting rhizobacteria,PGPR)借助其代谢过程或代谢产物来改善植物生长条件及营养环境.如固定空气中的游离氮,参与土壤中养分的转化,增加有效养分,分泌激素,刺激植物根系发育,抑制有害微生物活动,更重要的是有些PGPR能够诱导植物产生系统抗性.本文主要介绍了共生、非共生固氮菌和溶磷菌的功能以及应用,强调应在基础理论研究的基础上加大其产业化进展.

  19. [Construction of an engineered Acidithiobacillus caldus with high-efficiency arsenic resistance].

    Science.gov (United States)

    Zhao, Qing; Liu, Xiang-mei; Zhan, Yang; Lin, Jian-qun; Yan, Wang-ming; Bian, Jiang; Liu, Ying

    2005-10-01

    Using the recombinant technique in vitro, a new arsenic resistance plasmid pSDRA4 was constructed by subcloning the arsenic resistance genes from plasmid pUM3 into the wide-host-range IncQ plasmid pMMB24 with the hybrid trp-lac ( tac ) promoter, and followed by deleting the regulative gene of the promoter, the lacIQ gene. Then plasmid pSDRA4 was introduced from E. coli into extremely acidophilic obligately chemolithotrophic Acidithiobacillus caldus by conjugative transfer with a frequency of( 1.444 +/- 0.797) x 10(-4), and the engineered strain of Acidithiobacillus caldus (pSDRA4) for biomining was constructed. The successful transfer demonstrates the development of a conjugational system between strains of E. coli and A. caldus. The recombinant plasmid pSDRA4 is stable in A. caldus. Compared with wild type A. caldus, the level of the arsenic resistance of A. caldus (pSDRA4) is greatly raised from 10mmol/L to 45mmol/L. PMID:16342754

  20. [Variations of arsenic species in the solution of arsenic-contaminated paddy soil under flooding and at different temperatures].

    Science.gov (United States)

    Wang, Zhao; Cui, Jiang-Hui; Chen, Zheng; Lu, Xiu-Jun; Liu, Wen-Ju

    2013-05-01

    Taking arsenic (As)-contaminated paddy soil as test object, and by using high performance liquid chromatography inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), this paper studied the variations of As species in soil solution when the soil was sterilized or non-sterilized and incubated at different temperatures (5, 27, and 50 degrees C) under flooding. In the soil solution (pore water), only As(III) (arsenite), As(V) (arsenate), and DMA(V) ( dimethylarsinic acid) were detected, but no MMA(V)(mono methylarsinic acid) was found. With the increasing time of flooding and at the test temperatures, arsenite became the predominant species, averagely accounting for 64%, followed by As(V), with the proportion of 35%, and DMA(V), with the least proportion of 1%. Soil sterilization or non-sterilization had less effect on the concentrations of As(III) and DMA(V) in the soil solution, but remarkably affected the reduction of As(V) and the methylation of As(III). The promotion effect of soil sterilization decreased gradually with the increasing time of flooding and incubation. At 50 degrees C and after flooded for 23 days, the DMA(V) concentration in sterilized soil solution was the highest and up to 23.7 ng x mL(-1), indicating that some thermophilic microbes remained in sterilized soil became predominant species, and promoted the methylation of As(III) In sum, the total arsenic concentration in non-sterilized soil at incubation temperature 27 degrees C and flooded for 23 days was relatively low (501 ng x mL(-1)), and thus, in As-contaminated paddy rice planting areas, to adopt the water management mode of short cycle flooding-non-flooding could decrease the As level in soil solution as far as possible, and in the same time, save water resources and ensure yielding. PMID:24015564

  1. Current developments in toxicological research on arsenic.

    Science.gov (United States)

    Bolt, Hermann M

    2013-01-01

    There is a plethora of recent publications on all aspects relevant to the toxicology of arsenic (As). Over centuries exposures to arsenic continue to be a major public health problem in many countries. In particular, the occurrence of high As concentrations in groundwater of Southeast Asia receives now much attention. Therefore, arsenic is a high-priority matter for toxicological research. Key exposure to As are (traditional) medicines, combustion of As-rich coal, presence of As in groundwater, and pollution due to mining activities. As-induced cardiovascular disorders and carcinogenesis present themselves as a major research focus. The high priority of this issue is now recognized politically in a number of countries, research funds have been made available. Also experimental research on toxicokinetics and toxicodynamics and on modes of toxic action is moving very rapidly. The matter is of high regulatory concern, and effective preventive measures are required in a number of countries. PMID:27092031

  2. Determination of total arsenic in soil and arsenic-resistant bacteria from selected ground water in Kandal Province, Cambodia

    International Nuclear Information System (INIS)

    Cambodia has geological environments conducive to generation of high-arsenic groundwater and people are at high risk of chronic arsenic exposure. The aims of this study are to investigate the concentration of total arsenic and to isolate and identify arsenic-resistant bacteria from selected locations in Kandal Province, Cambodia. The INAA technique was used to measure the concentration of total arsenic in soils. The arsenic concentrations in soils were above permissible 5 mg/kg, ranging from 5.34 to 27.81 mg/kg. Bacteria resistant to arsenic from two arsenic-contaminated wells in Preak Russey were isolated by enrichment method in nutrient broth (NB). Colonies isolated from NB was then grown on minimal salt media (MSM) added with arsenic at increasing concentrations of 10, 20, 30, 50, 100 and 250 ppm. Two isolates that can tolerate 750 ppm of arsenic were identified as Enterobacter agglomerans and Acinetobacter lwoffii based on a series of biochemical, physiological and morphological analysis. Optimum growth of both isolates ranged from pH 6.6 to 7.0 and 30-35 deg C. E. agglomerans and A. lwoffii were able to remove 66.4 and 64.1 % of arsenic, respectively at the initial concentration of 750 ppm, within 72 h of incubation. Using energy dispersive X-ray technique, the percentage of arsenic absorbed by E. agglomerans and A. lwoffii was 0.09 and 0.15 %, respectively. This study suggested that arsenic-resistant E. agglomerans and A. lwoffii removed arsenic from media due to their ability to absorb arsenic. (author)

  3. Body composition and -174G/C interleukin-6 promoter gene polymorphism: association with progression of insulin resistance in normal weight obese syndrome.

    Science.gov (United States)

    Di Renzo, L; Bertoli, A; Bigioni, M; Del Gobbo, V; Premrov, M G; Calabrese, V; Di Daniele, N; De Lorenzo, A

    2008-01-01

    Insulin resistance and obesity are intimately related to a chronic low grade systemic inflammation. Interleukin-6 (IL-6) may influence the pathogenesis of obesity-related diseases. The aim of this study is to investigate the effect of body's fat mass on the relationships between -174G/C IL-6 promoter gene polymorphism, IL-6 circulating level and insulin resistance. A population of 150 Caucasian women was studied, subdivided according to their body composition in non-obese (NW), Normal Weight Obese (NWO) and preobese-obese (OB). The NWO subjects were found in an intermediate position between the NW and OB subjects in terms of body weight, fat mass percentage (FM%), abdominal FAT%, hs-CRP and plasma triglyceride level. Fasting plasma IL-6 concentration was positively correlated with the homeostasis model assessment for insulin resistance (HOMA-IR) in all subjects analyzed (P=0.0014). In NWO and OB women a significantly increased IL-6 mean value was observed compared with NW subjects. In G/G population, the IL-6 plasma level of NWO and OB was significantly higher with respect to NW. No significant differences of IL-6 concentrations were observed in the three groups carrying G/C genotype. NWO and OB women homozygous for the allele C have significantly lower value of IL-6 with respect to NW subjects. IL-6 concentration was positively correlated with FM% in G/G (R(2)=0.397, P<0.001) and was negatively correlated in C/C (R(2)=0.459, P=0.002). No significant correlation was observed in G/C genotype (R(2)=0.041, P=0.173). In conclusion our study confirms that, at least in Italian Caucasian females, the FM% is a major determinant of an increase in IL-6 production and insulin resistance. -174 G/C IL-6 promoter polymorphism represents a marker which could help to identify, time in advance, "vulnerable" individuals at risk of age and obesity related diseases. PMID:18991689

  4. Inorganic arsenic levels in baby rice are of concern

    International Nuclear Information System (INIS)

    Inorganic arsenic is a chronic exposure carcinogen. Analysis of UK baby rice revealed a median inorganic arsenic content (n = 17) of 0.11 mg/kg. By plotting inorganic arsenic against total arsenic, it was found that inorganic concentrations increased linearly up to 0.25 mg/kg total arsenic, then plateaued at 0.16 mg/kg at higher total arsenic concentrations. Inorganic arsenic intake by babies (4-12 months) was considered with respect to current dietary ingestion regulations. It was found that 35% of the baby rice samples analysed would be illegal for sale in China which has regulatory limit of 0.15 mg/kg inorganic arsenic. EU and US food regulations on arsenic are non-existent. When baby inorganic arsenic intake from rice was considered, median consumption (expressed as μg/kg/d) was higher than drinking water maximum exposures predicted for adults in these regions when water intake was expressed on a bodyweight basis. - Median consumption of organic arsenic levels for UK babies from baby rice is above threshold considered safe

  5. Arsenic in the environment: enrichments in the Slovenian soils

    Directory of Open Access Journals (Sweden)

    Mateja Gosar

    2005-12-01

    Full Text Available Arsenic, a toxic element with metalloid properties, is found in detectable concentrations in environmental samples. In nature it is enriched in metal (sulphide ore deposits, mainly as arsenides of Cu, Ni and Fe. Arsenic compounds are used mainly in agricultureand forestry as pesticides and herbicides. The ecosystem can be contaminated with arsenic via both natural and anthropogenic sources. Uses of arsenic contaminated water present so far the greatest health hazard. Occurrences of mining related arsenic problems havealso been recorded in many parts of the world.The impact of mining and metallurgic industry with regard to arsenic contents in soils in some potentially contaminated areas in Slovenia is discussed. Enriched contents of arsenic were found in Mežica. Arsenic correlates very well with lead, zinc and other heavymetals which are enriched as a result of long lasting lead production in the area. Also in Celje and Jesenice arsenic has the same distribution pattern as other anthropogenically introduced pollutants. In Idrija there are some slightly arsenic enriched areas, but there is no correlation with mercury, so the origin of arsenic in not clear yet.

  6. Inorganic arsenic levels in baby rice are of concern

    Energy Technology Data Exchange (ETDEWEB)

    Meharg, Andrew A. [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen AB24 3UU (United Kingdom)], E-mail: a.meharg@abdn.ac.uk; Sun, Guoxin [Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Williams, Paul N. [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen AB24 3UU (United Kingdom); Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Adomako, Eureka; Deacon, Claire [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen AB24 3UU (United Kingdom); Zhu, Yong-Guan [Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Feldmann, Joerg; Raab, Andrea [Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen AB24 3UE (United Kingdom)

    2008-04-15

    Inorganic arsenic is a chronic exposure carcinogen. Analysis of UK baby rice revealed a median inorganic arsenic content (n = 17) of 0.11 mg/kg. By plotting inorganic arsenic against total arsenic, it was found that inorganic concentrations increased linearly up to 0.25 mg/kg total arsenic, then plateaued at 0.16 mg/kg at higher total arsenic concentrations. Inorganic arsenic intake by babies (4-12 months) was considered with respect to current dietary ingestion regulations. It was found that 35% of the baby rice samples analysed would be illegal for sale in China which has regulatory limit of 0.15 mg/kg inorganic arsenic. EU and US food regulations on arsenic are non-existent. When baby inorganic arsenic intake from rice was considered, median consumption (expressed as {mu}g/kg/d) was higher than drinking water maximum exposures predicted for adults in these regions when water intake was expressed on a bodyweight basis. - Median consumption of organic arsenic levels for UK babies from baby rice is above threshold considered safe.

  7. Establishment of Groundwater Arsenic Potential Distribution and Discrimination in Taiwan

    Science.gov (United States)

    Tsai, Kuo Sheng; Chen, Yu Ying; Chung Liu, Chih; Lin, Chien Wen

    2016-04-01

    According to the last 10 years groundwater monitoring data in Taiwan, Arsenic concentration increase rapidly in some areas, similar to Bengal and India, the main source of Arsenic-polluted groundwater is geological sediments, through reducing reactions. There are many researches indicate that high concentration of Arsenic in groundwater poses the risk to water safety, for example, the farm lands irrigation water contains Arsenic cause the concentration of Arsenic increase in soil and crops. Based on the management of water usage instead of remediation in the situation of insufficient water. Taiwan EPA has been developed the procedures of Arsenic contamination potential area establishment and source discriminated process. Taiwan EPA use the procedures to determine the management of using groundwater, and the proposing usage of Arsenic groundwater accordance with different objects. Agencies could cooperate with the water quality standard or water needs, studying appropriate water purification methods and the groundwater depth, water consumption, thus achieve the goal of water safety and environmental protection, as a reference of policy to control total Arsenic concentration in groundwater. Keywords: Arsenic; Distribution; Discrimination; Pollution potential area of Arsenic; Origin evaluation of groundwater Arsenic

  8. Complementary arsenic speciation methods: A review

    Science.gov (United States)

    Nearing, Michelle M.; Koch, Iris; Reimer, Kenneth J.

    2014-09-01

    The toxicity of arsenic greatly depends on its chemical form and oxidation state (speciation) and therefore accurate determination of arsenic speciation is a crucial step in understanding its chemistry and potential risk. High performance liquid chromatography with inductively coupled mass spectrometry (HPLC-ICP-MS) is the most common analysis used for arsenic speciation but it has two major limitations: it relies on an extraction step (usually from a solid sample) that can be incomplete or alter the arsenic compounds; and it provides no structural information, relying on matching sample peaks to standard peaks. The use of additional analytical methods in a complementary manner introduces the ability to address these disadvantages. The use of X-ray absorption spectroscopy (XAS) with HPLC-ICP-MS can be used to identify compounds not extracted for HPLC-ICP-MS and provide minimal processing steps for solid state analysis that may help preserve labile compounds such as those containing arsenicsbnd sulfur bonds, which can degrade under chromatographic conditions. On the other hand, HPLC-ICP-MS is essential in confirming organoarsenic compounds with similar white line energies seen by using XAS, and identifying trace arsenic compounds that are too low to be detected by XAS. The complementary use of electrospray mass spectrometry (ESI-MS) with HPLC-ICP-MS provides confirmation of arsenic compounds identified during the HPLC-ICP-MS analysis, identification of unknown compounds observed during the HPLC-ICP-MS analysis and further resolves HPLC-ICP-MS by identifying co-eluting compounds. In the complementary use of HPLC-ICP-MS and ESI-MS, HPLC-ICP-MS helps to focus the ESI-MS selection of ions. Numerous studies have shown that the information obtained from HPLC-ICP-MS analysis can be greatly enhanced by complementary approaches.

  9. Anionic sorbents for arsenic and technetium species

    International Nuclear Information System (INIS)

    Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption

  10. Trivalent arsenic inhibits the functions of chaperonin complex.

    Science.gov (United States)

    Pan, Xuewen; Reissman, Stefanie; Douglas, Nick R; Huang, Zhiwei; Yuan, Daniel S; Wang, Xiaoling; McCaffery, J Michael; Frydman, Judith; Boeke, Jef D

    2010-10-01

    The exact molecular mechanisms by which the environmental pollutant arsenic works in biological systems are not completely understood. Using an unbiased chemogenomics approach in Saccharomyces cerevisiae, we found that mutants of the chaperonin complex TRiC and the functionally related prefoldin complex are all hypersensitive to arsenic compared to a wild-type strain. In contrast, mutants with impaired ribosome functions were highly arsenic resistant. These observations led us to hypothesize that arsenic might inhibit TRiC function, required for folding of actin, tubulin, and other proteins postsynthesis. Consistent with this hypothesis, we found that arsenic treatment distorted morphology of both actin and microtubule filaments. Moreover, arsenic impaired substrate folding by both bovine and archaeal TRiC complexes in vitro. These results together indicate that TRiC is a conserved target of arsenic inhibition in various biological systems. PMID:20660648

  11. Arsenic detection in water: YPO4:Eu3+ nanoparticles

    Science.gov (United States)

    Ghosh, Debasish; Luwang, Meitram Niraj

    2015-12-01

    This work reports on the novel technique of detection of arsenic in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Eu3+ (5%) doped YPO4nanorodswere utilised for the said experiment. Co-precipitation method was used for the synthesis of the materials and characterised them with different instrumental techniques like X-ray diffraction (XRD), Infra-red (IR), UV-absorption, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence studies. This nanoparticle can adsorb both arsenic and arsenious acids. We studied the effect of arsenic adsorption on the luminescence behaviour of the nanoparticles. Arsenic acid enhanced the luminescence intensity whereas arsenious acid quenched the luminescence. This luminescence enhancement or quenching is related with arsenic concentration. This relation of luminescence property with concentration of arsenic can be used to detect arsenic in industrial waste.

  12. Gut microbiome phenotypes driven by host genetics affect arsenic metabolism.

    Science.gov (United States)

    Lu, Kun; Mahbub, Ridwan; Cable, Peter Hans; Ru, Hongyu; Parry, Nicola M A; Bodnar, Wanda M; Wishnok, John S; Styblo, Miroslav; Swenberg, James A; Fox, James G; Tannenbaum, Steven R

    2014-02-17

    Large individual differences in susceptibility to arsenic-induced diseases are well-documented and frequently associated with different patterns of arsenic metabolism. In this context, the role of the gut microbiome in directly metabolizing arsenic and triggering systemic responses in diverse organs raises the possibility that gut microbiome phenotypes affect the spectrum of metabolized arsenic species. However, it remains unclear how host genetics and the gut microbiome interact to affect the biotransformation of arsenic. Using an integrated approach combining 16S rRNA gene sequencing and HPLC-ICP-MS arsenic speciation, we demonstrate that IL-10 gene knockout leads to a significant taxonomic change of the gut microbiome, which in turn substantially affects arsenic metabolism. PMID:24490651

  13. Method development for arsenic analysis by modification in spectrophotometric technique

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2012-01-01

    Full Text Available Arsenic is a non-metallic constituent, present naturally in groundwater due to some minerals and rocks. Arsenic is not geologically uncommon and occurs in natural water as arsenate and arsenite. Additionally, arsenic may occur from industrial discharges or insecticide application. World Health Organization (WHO and Pakistan Standard Quality Control Authority have recommended a permissible limit of 10 ppb for arsenic in drinking water. Arsenic at lower concentrations can be determined in water by using high tech instruments like the Atomic Absorption Spectrometer (hydride generation. Because arsenic concentration at low limits of 1 ppb can not be determined easily with simple spectrophotometric technique, the spectrophotometric technique using silver diethyldithiocarbamate was modified to achieve better results, up to the extent of 1 ppb arsenic concentration.

  14. RalA, a GTPase targeted by miR-181a, promotes transformation and progression by activating the Ras-related signaling pathway in chronic myelogenous leukemia

    Science.gov (United States)

    Luo, Xiaochuang; Yang, Juhua; Li, Yumin; Li, Tianfu; Wang, Ruirui; Fei, Jia

    2016-01-01

    BCR/ABL is a well-known activator of multiple signaling pathways. RalA, a Ras downstream signaling molecule and a small GTPase, plays an important role in Bcr-Abl-induced leukemogenesis but the exact mechanism remains elusive. Here, we show that RalA GTPase activity is commonly high in chronic myelogenous leukemia (CML) cell lines and patient samples. Overexpression of RalA results in malignant transformation and progression, and induces resistance to imatinib (IM) in BaF3 and K562 cell lines. RalA reduced survival and led to IM resistance in a xenografted mouse model. Ablation of RalA by either siRNA or miR-181a, a RalA targeting microRNA, attenuated the malignant phenotypes in K562 cells. RBC8, a selective Ral inhibitor, enhanced the inhibitory effects of IM in K562, KCL22 and BaF3-P210 cells. Interestingly, the phospho-specific protein microarray assay revealed that multiple phosphorylation signal proteins were decreased by RalA inhibition, including SAPK, JNK, SRC, VEGFR2, P38 MAPK, c-Kit, JunB, and Keratin18. Among them, P38 MAPK and SAPK/JNK are Ras downstream signaling kinases. Taken together, RalA GTPase might be an important oncogene activating the Ras-related signaling pathway in CML. PMID:26967392

  15. NO2 inhalation promotes Alzheimer’s disease-like progression: cyclooxygenase-2-derived prostaglandin E2 modulation and monoacylglycerol lipase inhibition-targeted medication

    Science.gov (United States)

    Yan, Wei; Yun, Yang; Ku, Tingting; Li, Guangke; Sang, Nan

    2016-03-01

    Air pollution has been reported to be associated with increased risks of cognitive impairment and neurodegenerative diseases. Because NO2 is a typical primary air pollutant and an important contributor to secondary aerosols, NO2-induced neuronal functional abnormalities have attracted greater attention, but the available experimental evidence, modulating mechanisms, and targeting medications remain ambiguous. In this study, we exposed C57BL/6J and APP/PS1 mice to dynamic NO2 inhalation and found for the first time that NO2 inhalation caused deterioration of spatial learning and memory, aggravated amyloid β42 (Aβ42) accumulation, and promoted pathological abnormalities and cognitive defects related to Alzheimer’s disease (AD). The microarray and bioinformation data showed that the cyclooxygenase-2 (COX-2)-mediated arachidonic acid (AA) metabolism of prostaglandin E2 (PGE2) played a key role in modulating this aggravation. Furthermore, increasing endocannabinoid 2-arachidonoylglycerol (2-AG) by inhibiting monoacylglycerol lipase (MAGL) prevented PGE2 production, neuroinflammation-associated Aβ42 accumulation, and neurodegeneration, indicating a therapeutic target for relieving cognitive impairment caused by NO2 exposure.

  16. 促进植物生长根圈细菌(PGPR)的研究现状%Review of Research Progress on Plant Growth Promoting Rhizobacteria (PGPR)

    Institute of Scientific and Technical Information of China (English)

    何铁光; 杨雯馨; 林崇宝; 何永群; 张野; 韦彩会; 李婷婷

    2014-01-01

    有机农业提倡与自然共存不破坏平衡,而自然界的土壤中存在许多可促进植物生长的植物根圈微生物(plant growth promoting rhizobacteria,PGPR),此类微生物可分泌促进植物生长的物质,并可诱导植物产生抗性基因,增强植物抗病.PGPR可产生有机物质促进植物生长,改善土壤肥力,增加可溶性磷及铁,诱发植物抗病、克服逆境、增强营养吸收,固氮或防治病害等,在有机农业上有助于植物增产,改善农业对化学肥料的依赖,生产出健康的作物.

  17. Occurrence of arsenic in plaice (Pleuronectes platessa), nature of organo-arsenic compound present and its excretion by man.

    OpenAIRE

    Luten, J B; Riekwel-Booy, G; Rauchbaar, A

    1982-01-01

    The arsenic content in 255 samples of plaice (Pleuronectes platessa) varied between 3 and 166 mg/kg. About 65% of the samples had an arsenic content above 10 mg/kg. High (low) arsenic concentration in the fillet corresponds with a high (low) concentration in milt or roe. An excretion experiment with eight human volunteers showed that after the consumption of plaice, 69-85% of the ingested arsenic was excreted in the urine within five days. The organo-arsenic compound present in plaice was iso...

  18. Biosensors for Inorganic and Organic Arsenicals

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2014-11-01

    Full Text Available Arsenic is a natural environmental contaminant to which humans are routinely exposed and is strongly associated with human health problems, including cancer, cardiovascular and neurological diseases. To date, a number of biosensors for the detection of arsenic involving the coupling of biological engineering and electrochemical techniques has been developed. The properties of whole-cell bacterial or cell-free biosensors are summarized in the present review with emphasis on their sensitivity and selectivity. Their limitations and future challenges are highlighted.

  19. Solubility and transport of arsenic coal ash

    International Nuclear Information System (INIS)

    An experimental method combined with a numerical model allows a comparison of two methods for the disposal of ash that contains arsenic, from the Rio Escondido coal-fired power plant. The calculation yields significant differences in aquifer migration times for the site. The wet disposal method gave 10 years time and the dry method gave 22 years. Experiments were performed on the rate of dissolution of the arsenic from ash samples; and these results indicate a first order kinetics reaction. 8 refs., 8 figs., 8 tabs

  20. Communication from the Commission to the Council and the European Parliament: progress report on the multiannual programme for the promotion of energy efficiency in the Community-SAVE II. Council Decision 96/737/EC Art.8.1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-17

    The SAVE II programme is dedicated to promoting the rational use of energy, focusing on the non-technological elements, helping to build the energy efficiency infrastructure and to improve policy analysis. The report provides a review of the activities and progress made since the approval of SAVE II, in five areas of action: studies and related actions aimed at implementing and completing Community measures such as the development of standards, studies on the effects of energy pricing on energy efficiency and studies helping to establish energy efficiency as a criterion within Community programmes; actions to accelerate energy efficiency investment and/or improving energy use patterns; measures to foster the exchange of experience; monitoring of energy efficiency progress in the Community and Member States; and specific actions at the regional and urban levels as well as improving the cohesion between Member States and regions in the field of energy efficiency. Annexes list funding for 1996 and 1997 and topics proposed for study in 1998.

  1. Determination of arsenic in crude petroleum and liquid hydrocarbons.

    Science.gov (United States)

    Puri, B K; Irgolic, K J

    1989-12-01

    Total arsenic was determined in crude petroleum and liquid hydrocarbons derived from crude petroleum by extraction with boiling water or boiling aqueous nitric acid (concentration 0.25 to 2.5 M), mineralization of the extracts with concentrated nitric/sulphuric acid, and reduction of the arsenate to arsine in a hydride generator. The arsine was flushed into a helium-DC plasma. The arsenic emission was monitored at 228.8 nm. The total arsenic concentration in 53 crude oil samples ranged from 0.04 to 514 mg L(-1) (median 0.84 mg L(-1)). Arsenic was also determined in several refined liquid hydrocarbons and in a commercially available arsenic standard in an organic matrix (triphenylarsine in xylene). The method was checked with NIST 1634b "Trace Elements in Residual Fuel Oil". The arsenic concentration found in this standard agreed with the certified value (0.12±0.2 μg g(-1)) within experimental error. Viscous hydrocarbons such as the fuel oil must be dissolved in xylene for the extraction to be successful. Hydride generation applied to an aqueous not-mineralized extract from an oil containing 1.67 μg As mL(-1) revealed, that trimethylated arsenic (520 ng mL(-1)) is the predominant arsenic species among the reducible and detectable arsenic compounds. Monomethylated arsenic (104 ng ml(-1)), inorganic arsenic (23 ng mL(-1)), and dimethylated arsenic (low ng mL(-1)) were also detected. The sum of the concentrations of these arsenic species accounts for only 39% of the total arsenic in the sample. PMID:24202418

  2. Removal of Arsenic from Drinking Water by Adsorption and Coagulation

    Science.gov (United States)

    Zhang, M.; Sugita, H.; Hara, J.; Takahashi, S.

    2013-12-01

    Removal of arsenic from drinking water has been an important issue worldwide, which has attracted greater attentions in recent years especially for supplying safe drinking water in developing countries. Although many kinds of treatment approaches that are available or applicable both in principle and practice, such as adsorption, coagulation, membrane filtration, ion exchange, biological process, electrocoagulation and so on, the first 2 approaches (i.e., adsorption and coagulation) are most promising due to the low-cost, high-efficiency, simplicity of treating systems, and thus can be practically used in developing countries. In this study, a literature survey on water quality in Bangladesh was performed to understand the ranges of arsenic concentration and pH of groundwater in Bangladesh. A series of tests were then organized and performed to investigate the effects of arsenic concentration, arsenic forms, pH, chemical compositions of the materials used for adsorption and coagulation, particle size distribution and treatment time on quality of treated water. The experimental results obtained in the study illustrated that both adsorption and coagulation can be used to effectively reduce the concentrations of either arsenic (V) or arsenic (III) from the contaminated water. Coagulation of arsenic with a magnesium-based material developed in this study can be very effective to remove arsenic, especially arsenic (V), from contaminated water with a concentration of 10 ppm to an undetectable level of 0.002 ppm by ICP analyses. Compared to arsenic (III), arsenic (V) is easier to be removed. The materials used for adsorption and coagulation in this study can remove arsenic (V) up to 9 mg/g and 6 mg/g, and arsenic (III) up to 4 mg/g and 3 mg/g, respectively, depending on test conditions and compositions of the materials being used. The control of pH during treatment can be a challenging technical issue for developing both adsorbent and coagulant. Keywords: Water Treatment

  3. THE ROLE OF ARSENIC (+3 OXIDATION STATE) METHYLTRANSFERASE IN ARSENIC METABOLISM

    Science.gov (United States)

    Arsenic (As) is widely distributed in the environment. Epidemiological studies have linked chronic exposures to inorganic As (iAs) to adverse health effects such as skin lesions, peripheral neuropathy, cardiovascular, hepatic and renal disorders, diabetes mellitus, skin cancer,...

  4. Arsenic resistant bacteria isolated from arsenic contaminated river in the Atacama Desert (Chile).

    Science.gov (United States)

    Escalante, G; Campos, V L; Valenzuela, C; Yañez, J; Zaror, C; Mondaca, M A

    2009-11-01

    In this study, arsenic resistant bacteria were isolated from sediments of an arsenic contaminated river. Arsenic tolerance of bacteria isolated was carried out by serial dilution on agar plate. Redox abilities were investigated using KMnO4. arsC and aox genes were detected by PCR and RT-PCR, respectively. Bacterial populations were identified by RapID system. Forty nine bacterial strains were isolated, of these, 55 % corresponded to the reducing bacteria, 4% to oxidizing bacteria, 8% presented both activities and in 33% of the bacteria none activity was detected. arsC gene was detected in 11 strains and aox genes were not detected. The activity of arsenic transforming microorganisms in river sediment has significant implications for the behavior of the metalloid. PMID:19779656

  5. Evaluation of two new arsenic field test kits capable of detecting arsenic water concentrations close to 10 microg/L.

    Science.gov (United States)

    Steinmaus, Craig M; George, Christine M; Kalman, David A; Smith, Allan H

    2006-05-15

    Millions of people worldwide are exposed to arsenic-contaminated drinking water. Arsenic field test kits may offer a cost-effective approach for measuring these exposures in the field, although the accuracy of some kits used in the past has been poor. In this study, arsenic concentrations were measured in 136 water sources in western Nevada using two relatively new arsenic test kits and compared to laboratory measurements using atomic fluorescence spectroscopy (AFS). Spearman's rank correlation coefficients comparing the Quick Arsenic and Hach EZ kits to laboratory measurements were 0.96 (p or = 500 microg/L), test kit and AFS measurements were in the same category in 71% (Quick Arsenic) and 62% (Hach EZ) of samples, and within one category of each other in 99% (Quick Arsenic) and 97% (Hach EZ) of samples. Both kits identified all water samples with high arsenic concentrations (> 15 microg/L) as being above the United States Environmental Protection Agency's drinking water standard and the World Health Organization's guideline value for arsenic of 10 microg/L. These results suggestthatthese easily portable kits can be used to identify water sources with high arsenic concentrations and may provide an important tool for arsenic surveillance and remediation programs. PMID:16749706

  6. TSPY potentiates cell proliferation and tumorigenesis by promoting cell cycle progression in HeLa and NIH3T3 cells

    International Nuclear Information System (INIS)

    TSPY is a repeated gene mapped to the critical region harboring the gonadoblastoma locus on the Y chromosome (GBY), the only oncogenic locus on this male-specific chromosome. Elevated levels of TSPY have been observed in gonadoblastoma specimens and a variety of other tumor tissues, including testicular germ cell tumors, prostate cancer, melanoma, and liver cancer. TSPY contains a SET/NAP domain that is present in a family of cyclin B and/or histone binding proteins represented by the oncoprotein SET and the nucleosome assembly protein 1 (NAP1), involved in cell cycle regulation and replication. To determine a possible cellular function for TSPY, we manipulated the TSPY expression in HeLa and NIH3T3 cells using the Tet-off system. Cell proliferation, colony formation assays and tumor growth in nude mice were utilized to determine the TSPY effects on cell growth and tumorigenesis. Cell cycle analysis and cell synchronization techniques were used to determine cell cycle profiles. Microarray and RT-PCR were used to investigate gene expression in TSPY expressing cells. Our findings suggest that TSPY expression increases cell proliferation in vitro and tumorigenesis in vivo. Ectopic expression of TSPY results in a smaller population of the host cells in the G2/M phase of the cell cycle. Using cell synchronization techniques, we show that TSPY is capable of mediating a rapid transition of the cells through the G2/M phase. Microarray analysis demonstrates that numerous genes involved in the cell cycle and apoptosis are affected by TSPY expression in the HeLa cells. These data, taken together, have provided important insights on the probable functions of TSPY in cell cycle progression, cell proliferation, and tumorigenesis

  7. Research Progress of Promoting Silage Additives%发酵促进型青贮添加剂的研究进展及其应用现状

    Institute of Scientific and Technical Information of China (English)

    郭盼; 单贵莲; 薛世明; 杨国荣

    2012-01-01

    Silage additives is one of the important measures to improve silage quality. In recent decades, we have done lots of researches in additive in forage silage, and has made a great progress, and become the focus of silage fermation. The type of silage addition is the hotspot in recent years. This paper reviews some type of the silage addition, like the lactic acid bacteria, cellulase enzymes, previously fermented juice and sugar and so on, and point out the research situation, the exiting problems and the future trends.%青贮添加剂是提高青贮饲料品质的重要措施之一。近几十年来,人们对于添加剂在牧草青贮技术中的应用进行了大量的研究,而且取得了重要进展,并成为目前青贮技术发展的重点,其中发酵促进型添加剂是近年来研究的热点。本文对乳酸茵、纤维素酶、绿汁发酵液和糖类等发酵促进型牧草青贮添加剂的研究进行了综述,阐述了研究的现状,指出了存在的问题,并对未来的趋势进行了展望。

  8. AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers

    International Nuclear Information System (INIS)

    We have previously identified actin filament-associated protein 1-like 1 (AFAP1L1) as a metastasis-predicting marker for spindle cell sarcomas by gene expression profiling, and demonstrated that AFAP1L1 is involved in the cell invasion process by in vitro analyses. However, its precise molecular function has not been fully elucidated, and it remains unknown whether AFAP1L1 could be a prognostic marker and/or therapeutic target of other malignancies. In this study, we found a marked elevation of AFAP1L1 gene expression in colorectal cancer (CRC) tissues as compared to the adjacent normal mucosa. Multivariate analysis revealed that AFAP1L1 was an independent and significant factor for the recurrence of rectal cancers. Moreover, the addition of the AFAP1L1 expression level to the lymph node metastasis status provided more predictive information regarding postoperative recurrence in rectal cancers. AFAP1L1-transduced CRC cells exhibited a rounded shape, increased cell motility on planar substrates, and resistance to anoikis in vitro. AFAP1L1 localized to the ringed structure of the invadopodia, together with vinculin, and AFAP1L1 was identified as a novel associating partner of vinculin by immunoprecipitation assay. AFAP1L1-transduced cells showed accelerated tumor growth in vivo, presumably reflecting the anoikis resistance of these AFAP1L1-expressing cells. Furthermore, the local administration of a siRNA against AFAP1L1 significantly suppressed the in vivo tumor growth of xenografts, suggesting that AFAP1L1 might be a candidate therapeutic target for CRCs. These results suggest that AFAP1L1 plays a role in the progression of CRCs by modulating cell shape and motility and by inhibiting anoikis, presumably through interactions with vinculin-including protein complexes

  9. The MRP2/cMOAT transporter and arsenic-glutathione complex formation are required for biliary excretion of arsenic.

    Science.gov (United States)

    Kala, S V; Neely, M W; Kala, G; Prater, C I; Atwood, D W; Rice, J S; Lieberman, M W

    2000-10-27

    Worldwide, millions of people are exposed to arsenic in drinking water that exceeds the World Health Organization standard of 10 microg/liter by as much as 50-300-fold, yet little is known about the molecular basis for arsenic excretion. Here we show that transport of arsenic into bile depends on the MRP2/cMOAT transporter and that glutathione is obligatory for such transport. Using reversed phase liquid chromatography/mass spectrometry, we demonstrate that two arsenic-glutathione complexes not previously identified in vivo, arsenic triglutathione and methylarsenic diglutathione, account for most of the arsenic in the bile. The structure of the compounds was also confirmed by nuclear magnetic resonance spectroscopy. Our findings may help explain the increased susceptibility of malnourished human populations to arsenic. PMID:10938093

  10. Preliminary study on the mode of occurrence of arsenic in high arsenic coals from southwest Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    丁振华; 郑宝山; 张杰; H.; E.; Belkin; R.; B.; Finkelman; 赵峰华; 周代兴; 周运书; 陈朝刚

    1999-01-01

    Coal samples from high arsenic coal areas have been analyzed by electron microprobe analyzer ( EMPA) , scanning electron microscopy with an energy dispersive X-ray analyzer (SEM-EDX) , X-ray diffraction analysis (XRD) , low temperature ashing (LTA) , transmission electron microscopy (TEM) , X-ray absorption fine structure (XAFS) , instrument neutron activation analysis (INAA) and wet chemical analysis. Although some As-bearing minerals such as pyrite, arsenopyrite, realgar (?), As-bearing sulfate, and As-bearing clays are found in the high arsenic coals, their contents do not account for the abundance of arsenic in the some coals. Analysis of the coal indicates that arsenic exists mainly in the form of As5+ and As3+ , combined with compounds in the organic matrix. The occurrence of such exceptionally high arsenic contents in coal and the fact that the arsenic is dominantly organically associated are unique observations. The modes of occurrence of arsenic in high As-coals are discussed.

  11. Mechanism of arsenic tolerance and bioremoval of arsenic by Acidithiobacilus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Chandra Prabha M N

    2011-08-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 This paper reports the studies on mechanism of arsenic tolerance and bioremoval of arsenic ions (arsenite or arsenate by Acidithiobacillus ferrooxidans. Exposure of cells to arsenic ions resulted in increased cell surface hydrophobicity, decreased electrophoretic mobility and stronger adsorption affinity towards arsenopyrite. The mechanism of tolerance to arsenic ions were specific and could be attributed to the changes in specific protein expression in the outer membrane and cytosolic membrane fractions. Biosorption studies showed decrease in solution arsenic concentration only with ferrous–grown cells indicating that presence of ferric ions in the EPS was necessary for binding or entrapment of arsenic ions in the EPS. Bacterial EPS of ferrous–grown wild cells were able to uptake arsenate ions due to the strong affinity of ferric ions towards arsenate ions. Neither cells nor the ferric ions were capable of precipitating or oxidizing arsenite ions directly. Both arsenate ions and arsenite ions were co–precipitated with ferric ions formed during the growth of the bacteria.  

  12. Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non-hyperaccumulating ferns

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Nandita [Soil and Water Science Department, University of Florida, Gainesville, Fl 32611-0290 (United States); Eco-Auditing group, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001 (India); Ma, Lena Q., E-mail: lqma@ufl.ed [Soil and Water Science Department, University of Florida, Gainesville, Fl 32611-0290 (United States); Vu, Joseph C. [Chemistry Research Unit, CMAVE, USDA-ARS, Gainesville, FL 32608-1069 and Agronomy Department, University of Florida, Gainesville, FL 32611-0500 (United States); Raj, Anshita [Eco-Auditing group, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001 (India)

    2009-08-15

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of four-month old Pteris vittata (arsenic - hyperaccumulator) and Pteris ensiformis (non-arsenic--hyperaccumulator) plants. The arsenic treatments (0, 150, and 300 muM as sodium arsenate) in hydroponics had adverse effects on the root and frond dry weights, and this effect was more evident in P. ensiformis than in P. vittata. Nitrate reductase and nitrite reductase activities of arsenate-treated plants were reduced more in P. ensiformis than in P. vittata. This effect was accompanied by similar decreases in tissue NO{sub 3}{sup -} concentrations. Therefore, this decrease is interpreted as being indirect, i.e., the consequence of the reduced NO{sub 3}{sup -} uptake and translocation in the plants. The study shows the difference in the tolerance level of the two Pteris species with varying sensitivity to arsenic. - Arsenic reduced the activity of nitrate and nitrite reductase more in Pteris ensiformis than Pteris vittata.

  13. Impact of arsenic on uptake and bio-accumulation of antimony by arsenic hyperaccumulator Pteris vittata

    International Nuclear Information System (INIS)

    Individual uptake of As and Sb species in Pteris vittata have been investigated, but little information is available how uptake is affected if both metalloids are simultaneously present in different amounts. We investigated the uptake of antimony and its speciation in Pteris vittata cultivated in quartz substrate with, versus without, co-contamination with arsenic and a contaminated soil for 7 weeks. Applying HPLC-ICP-MS technique Sb(V), Sb(III), As(III), and As(V) could be identified as main species in aqueous extracts of roots and fronds with up to 230 mg kg−1 of total Sb in the roots. Adding increasing amounts of As to the quartz substrate resulted in increasing uptake of Sb. In contrast to As, which is readily transferred to the fronds, Sb is primarily accumulated in the roots with Sb(V) being the dominant species (>90% of Sb). The addition of As doesn't result in enhanced translocation of Sb into the fronds. Highlights: ► Antimonate is bioavailable to P. vittata grown for 7 weeks in different substrates. ► Antimony is primarily accumulated in the roots with Sb(V) being the dominant species. ► Sb(III) is present to a somewhat higher portion in the fronds than in the roots. ► Increasing amounts of As(V) in substrate resulted in increasing uptake of Sb(V). ► Addition of As is not accompanied by any alteration of Sb translocation to fronds. -- Roots of Pteris vittata cultivated under green-house conditioned in substrates containing antimonate accumulates Sb(V). This was promoted by As(V)

  14. Parageneses and Crystal Chemistry of Arsenic Minerals

    Czech Academy of Sciences Publication Activity Database

    Majzlan, J.; Drahota, P.; Filippi, Michal

    Chantilly: Mineralogical Society of America, 2014 - (Bowell, J.; Alpers, C.; Jamieson, H.; Nordstrom, D.; Majzlan, J.), s. 17-184. (Reviews in Mineralogy and Geochemistry. 79). ISBN 978-0-939950-94-2 Institutional research plan: CEZ:AV0Z30130516 Institutional support: RVO:67985831 Keywords : arsenic * mineralogy * parageneses * crystal structure Subject RIV: DB - Geology ; Mineralogy

  15. 29 CFR 1910.1018 - Inorganic arsenic.

    Science.gov (United States)

    2010-07-01

    ... rise to radiological evidence or pneumoconiosis. Arsenic does have a depressant effect upon the bone... regulated areas, food or beverages are not consumed, smoking products, chewing tobacco and gum are not used...-practice controls. (ii) Work operations, such as maintenance and repair activities, for which the...

  16. Arsenic - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... español) Chinese - Simplified (简体中文) Arsenic English 关于砷的常问问题 - 简体中文 (Chinese - Simplified) Food and Drug Administration Spanish (español) Arsénico Characters not ...

  17. Questions and Answers: Apple Juice and Arsenic

    Science.gov (United States)

    ... and monomethylarsonic acid (MMA), may also be a health concern. Are apple and other fruit juices safe to drink? The FDA has been ... this, the FDA is considering how any possible health risk from these two forms of ... arsenic in fruit juice? The FDA has proposed an “action level” ...

  18. Arsenic accumulation in some higher fungi

    NARCIS (Netherlands)

    Stijve, T.; Vellinga, Else C.; Herrmann, A.

    1990-01-01

    The high arsenic concentrations reported in literature for Laccaria amethystina were amply confirmed. In addition, it was demonstrated that Laccaria fraterna also accumulates the element, whereas in other species of Laccaria the phenomenon was far less outspoken. Few other basidiomycetes proved to h

  19. Speciation of arsenic in environmental waters

    International Nuclear Information System (INIS)

    A system for speciation of arsenic in environmental waters by selective hydride formation and on-line AAS is described. Starting from literature data, the separation scheme and the necessary apparatus are outlined. Preliminary practical experience then leads to the formulation of further improvements and accompanying testing experiments. (author). 51 refs, 7 figs, 1 tab

  20. Arsenic(III Immobilization on Rice Husk

    Directory of Open Access Journals (Sweden)

    Malay Chaudhuri

    2013-02-01

    Full Text Available A number of large aquifers in various parts of the world have been identified with contamination by arsenic. Long-term exposure to arsenic in drinking water causes cancer of the skin, lungs, urinary bladder and kidney, as well as skin pigmentation and hyperkeratosis. Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III] and pentavalent arsenate [As(V]. As(III is more toxic and more difficult to remove from water by adsorption on activated alumina. In this study, immobilization (adsorption of As(III by quaternized rice husk was examined. Batch adsorption test showed that extent of adsorption was dependent on pH, As (III concentration, contact time and rice husk dose. Maximum adsorption occurred at pH 7-8, and equilibrium adsorption was attained in 2 h. Equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. According to the Langmuir isotherm, adsorption capacity of quaternized rice husk is 0.775 mg As(III/g, which is 4.3x higher than that (0.180 mg As(III/g of activated alumina. Quaternized rice husk is a potentially useful adsorbent for removing arsenic from groundwater.

  1. Arsenic mobilization from sediments in microcosms under sulfate reduction.

    Science.gov (United States)

    Sun, Jing; Quicksall, Andrew N; Chillrud, Steven N; Mailloux, Brian J; Bostick, Benjamin C

    2016-06-01

    Arsenic is often assumed to be immobile in sulfidic environments. Here, laboratory-scale microcosms were conducted to investigate whether microbial sulfate reduction could control dissolved arsenic concentrations sufficiently for use in groundwater remediation. Sediments from the Vineland Superfund site and the Coeur d'Alene mining district were amended with different combination of lactate and sulfate and incubated for 30-40 days. In general, sulfate reduction in Vineland sediments resulted in transient and incomplete arsenic removal, or arsenic release from sediments. Sulfate reduction in the Coeur d'Alene sediments was more effective at removing arsenic from solution than the Vineland sediments, probably by arsenic substitution and adsorption within iron sulfides. X-ray absorption spectroscopy indicated that the Vineland sediments initially contained abundant reactive ferrihydrite, and underwent extensive sulfur cycling during incubation. As a result, arsenic in the Vineland sediments could not be effectively converted to immobile arsenic-bearing sulfides, but instead a part of the arsenic was probably converted to soluble thioarsenates. These results suggest that coupling between the iron and sulfur redox cycles must be fully understood for in situ arsenic immobilization by sulfate reduction to be successful. PMID:27037658

  2. Arsenic hydrogeochemistry in an irrigated river valley - A reevaluation

    Science.gov (United States)

    Nimick, D.A.

    1998-01-01

    Arsenic concentrations in ground water of the lower Madison River valley, Montana, are high (16 to 176 ??g/L). Previous studies hypothesized that arsenic-rich river water, applied as irrigation, was evapoconcentrated during recharge and contaminated the thin alluvial aquifer. Based on additional data collection and a reevaluation of the hydrology and geochemistry of the valley, the high arsenic concentrations in ground water are caused by a unique combination of natural hydrologic and geochemical factors, and irrigation appears to play a secondary role. The high arsenic concentrations in ground water have several causes: direct aquifer recharge by Madison River water having arsenic concentrations as high as 100 ??g/L, leaching of arsenic from Tertiary volcano-clastic sediment, and release of sorbed arsenic where redox conditions in ground water are reduced. The findings are consistent with related studies that demonstrate that arsenic is sorbed by irrigated soils in the valley. Although evaporation of applied irrigation water does not significantly increase arsenic concentrations in ground water, irrigation with arsenic-rich water raises other environmental concerns.

  3. Evaluation of Exposure to Arsenic in Residential Soil

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Joyce S.; Van Kerkhove, Maria D.; Kaetzel, Rhonda; Scrafford, Carolyn; Mink, Pamela; Barraj, Leila M.; Crecelius, Eric A.; Goodman, Michael

    2005-12-01

    In response to concerns regarding arsenic in soil from a pesticide manufacturing plant, we conducted a biomonitoring study on children younger than 7 years of age, the age category of children most exposed to soil. Urine samples from 77 children (47% participation rate) were analyzed for total arsenic and arsenic species related to ingestion of inorganic arsenic. Older individuals also provided urine (n = 362) and toenail (n = 67) samples. Speciated urinary arsenic levels were similar between children (geometric mean, geometric SD, and range: 4.0, 2.2, and 0.89?17.7 ?g/L, respectively) and older participants (3.8, 1.9, 0.91?19.9 ?g/L) and consistent with unexposed populations. Toenail samples were < 1 mg/kg. Correlations between speciated urinary arsenic and arsenic in soil (r = 0.137, p = 0.39; n = 41) or house dust (r = 0.049, p = 0.73; n = 52) were not significant for children. Similarly, questionnaire responses indicating soil exposure were not associated with increased urinary arsenic levels. Relatively low soil arsenic exposure likely precluded quantification of arsenic exposure above background.

  4. Evaluation of electrokinetic remediation of arsenic-contaminated soils.

    Science.gov (United States)

    Kim, Soon-Oh; Kim, Won-Seok; Kim, Kyoung-Woong

    2005-09-01

    The potential of electrokinetic (EK) remediation technology has been successfully demonstrated for the remediation of heavy metal-contaminated fine-grained soils through laboratory scale and field application studies. Arsenic contamination in soil is a serious problem affecting both site use and groundwater quality. The EK technology was evaluated for the removal of arsenic from two soil samples; a kaolinite soil artificially contaminated with arsenic and an arsenic-bearing tailing-soil taken from the Myungbong (MB) gold mine area. The effectiveness of enhancing agents was investigated using three different types of cathodic electrolytes; deionized water (DIW), potassium phosphate (KH(2)PO(4)) and sodium hydroxide (NaOH). The results of the experiments on the kaolinite show that the potassium phosphate was the most effective in extracting arsenic, probably due to anion exchange of arsenic species by phosphate. On the other hand, the sodium hydroxide seemed to be the most efficient in removing arsenic from the tailing-soil. This result may be explained by the fact that the sodium hydroxide increased the soil pH and accelerated ionic migration of arsenic species through the desorption of arsenic species as well as the dissolution of arsenic-bearing minerals. PMID:16237600

  5. Soil Contamination by Arsenic in Urban Areas: A case study of Arak City

    Directory of Open Access Journals (Sweden)

    E Solgi

    2015-08-01

    Conclusion: It seems that arsenic in soil is controlled by natural and anthropogenic factors. The highest concentrations of arsenic in center and the north areas reflected arsenic loading is originated from anthropogenic sources such as vehicles and industrial processes.

  6. Arsenic cycling in hydrocarbon plumes: secondary effects of natural attenuation

    Science.gov (United States)

    Cozzarelli, Isabelle M.; Schreiber, Madeline E.; Erickson, Melinda L.; Ziegler, Brady A.

    2016-01-01

    Monitored natural attenuation is widely applied as a remediation strategy at hydrocarbon spill sites. Natural attenuation relies on biodegradation of hydrocarbons coupled with reduction of electron acceptors, including solid phase ferric iron (Fe(III)). Because arsenic (As) adsorbs to Fe-hydroxides, a potential secondary effect of natural attenuation of hydrocarbons coupled with Fe(III) reduction is a release of naturally occurring As to groundwater. At a crude-oil-contaminated aquifer near Bemidji, Minnesota, anaerobic biodegradation of hydrocarbons coupled to Fe(III) reduction has been well documented. We collected groundwater samples at the site annually from 2009 to 2013 to examine if As is released to groundwater and, if so, to document relationships between As and Fe inside and outside of the dissolved hydrocarbon plume. Arsenic concentrations in groundwater in the plume reached 230 µg/L, whereas groundwater outside the plume contained less than 5 µg/L As. Combined with previous data from the Bemidji site, our results suggest that (1) naturally occurring As is associated with Fe-hydroxides present in the glacially derived aquifer sediments; (2) introduction of hydrocarbons results in reduction of Fe-hydroxides, releasing As and Fe to groundwater; (3) at the leading edge of the plume, As and Fe are removed from groundwater and retained on sediments; and (4) downgradient from the plume, patterns of As and Fe in groundwater are similar to background. We develop a conceptual model of secondary As release due to natural attenuation of hydrocarbons that can be applied to other sites where an influx of biodegradable organic carbon promotes Fe(III) reduction.

  7. Inverse association between toenail arsenic and body mass index in a population of welders

    OpenAIRE

    Grashow, Rachel; Zhang, Jinming; Fang, Shona C; Weisskopf, Marc G.; Christiani, David C.; Kile, Molly L.; Cavallari, Jennifer M

    2014-01-01

    Recent data show that arsenic may play a role in obesity-related diseases. However, urinary arsenic studies report an inverse association between arsenic level and body mass index (BMI). We explored whether toenail arsenic, a long-term exposure measure, was associated with BMI in 74 welders with known arsenic exposure. BMI showed significant inverse associations with toenail arsenic (p=0.01), which persisted in models adjusted for demographics, diet and work history. It is unclear whether low...

  8. In Vivo Assessment of Arsenic Bioavailability in Rice and Its Significance for Human Health Risk Assessment

    OpenAIRE

    Juhasz, Albert L.; Smith, Euan; Weber, John; Rees, Matthew; Rofe, Allan; Kuchel, Tim; Sansom, Lloyd; Naidu, Ravi

    2006-01-01

    Background Millions of people worldwide consume arsenic-contaminated rice; however, little is known about the uptake and bioavailability of arsenic species after arsenic-contaminated rice ingestion. Objectives In this study, we assessed arsenic speciation in greenhouse-grown and supermarket-bought rice, and determined arsenic bioavailability in cooked rice using an in vivo swine model. Results In supermarket-bought rice, arsenic was present entirely in the inorganic form compared to greenhous...

  9. Association of Genetic Variation in Cystathionine-β-Synthase and Arsenic Metabolism

    OpenAIRE

    Porter, Kristin E.; Basu, Anamika; Alan E Hubbard; Bates, Michael N.; Kalman, David; Rey, Omar; Smith, Allan; Smith, Martyn T.; Steinmaus, Craig; Skibola, Christine F.

    2010-01-01

    Variation in individual susceptibility to arsenic-induced disease may be partially explained by genetic differences in arsenic metabolism. Mounting epidemiological evidence and in vitro studies suggest that methylated arsenic metabolites, particularly monomethylarsonic (MMA3), are more acutely toxic than inorganic arsenic; thus, MMA3 may be the primary toxic arsenic species. To test the role of genetic variation in arsenic metabolism, polymorphisms in genes involved in one-carbon metabolism [...

  10. geochemical controls on arsenic and phosphorus in natural and engineered systems

    OpenAIRE

    Davis, Jason Edward

    2000-01-01

    This thesis elucidates fundamental reactions that can control concentrations of arsenic and phosphate in water sources. High levels of arsenic or phosphorus have significant implications for the environment-- arsenic is extremely toxic to humans while phosphorus can cause eutrophication. Initial work focused on arsenic solids that might exert geochemical control on soluble arsenic. Formation of proposed iron, barium, copper and zinc-arsenic solids were systematically examined under ...

  11. Arsenic Contamination in Groundwater of Bangladesh: Perspectives on Geochemical, Microbial and Anthropogenic Issues

    Directory of Open Access Journals (Sweden)

    Shafi M. Tareq

    2011-11-01

    Full Text Available A groundwater, sediment and soil chemistry and mineralogical study has been performed to investigate the sources and mobilization process of Arsenic (As in shallow aquifers of Bangladesh. The groundwater from the shallow aquifers is characterized by high concentrations of Arsenic (47.5–216.8 µg/L, iron (0.85–5.83 mg/L, and phosphate, along with high electrical conductivity (EC. The groundwater has both very low oxidation-reduction potential (Eh and dissolved oxygen (DO values indicating reducing conditions. By contrast, the deep aquifers and surface waters (pond, canal have very low concentrations of Arsenic ( < 6 µg/L, iron (0.12–0.39 mg/L, and phosphate along with a relatively low EC. Furthermore, the values of Eh and DO are high, indicating oxic to suboxic conditions. Arsenic is inversely correlated with Eh values in the upper aquifer, whereas no relationship in the deeper aquifer is observed. These results suggest that As mobilization is clearly linked to the development of reducing conditions. The clayey silt, enriched in Fe, Mn, Al oxides and organic matter, and deposited in the middle unit of shallow aquifers, contains moderately high concentrations of As, whereas the sediments of deep aquifers and silty mud surface soils from paddy fields and ponds contain a low content of As (Daudkandi area. Arsenic is strongly correlated with the concentrations of Fe, Mn and Al oxides in the core samples from the Daudkandi and Marua areas. Arsenic is present in the oxide phase of Fe and Mn, phyllosilicate minerals and in organic matter in sediments. This study suggests that adsorption or precipitation of As-rich Fe oxyhydroxide on the surface or inner sites of biotite might be responsible for As concentrations found in altered biotite minerals by Seddique et al. Microbially or geochemically mediated reductive dissolution of Fe oxyhydroxides is the main mechanism for As release. The reducing conditions are caused by respiratory decomposition of

  12. Total and inorganic arsenic in fish samples from Norwegian waters

    DEFF Research Database (Denmark)

    Julshamn, K.; Nilsen, B. M.; Frantzen, S.;

    2012-01-01

    The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Arctic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast...... of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography–ICP-MS following microwave......-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg–1 wet weight. For inorganic arsenic, the concentrations found were very low (...

  13. Groundwater arsenic concentrations in Vietnam controlled by sediment age

    DEFF Research Database (Denmark)

    Postma, Dieke; Larsen, Flemming; Thai, Nguyen Thi; Trang, Pham Thi Kim; Jakobsen, Rasmus; Nhan, Pham Quy; Long, Tran Vu; Viet, Pham Hung; Murray, Andrew Sean

    2012-01-01

    Arsenic contamination of groundwater continues to threaten the health of millions of people in southeast Asia. The oxidation of organic carbon, coupled to the reductive dissolution of arsenic-bearing iron oxides, is thought to control the release of sediment-bound arsenic into groundwater. However......, the cause of the high spatial variability in groundwater arsenic concentrations—which can range from 5 to 500 μg l−1 within distances of a few kilometres—has been uncertain. Here, we combine measurements of sediment age, organic-matter reactivity and water chemistry at four locations along a cross......-section of the arsenic-contaminated Red River floodplain in Vietnam to determine the origin of variations in groundwater arsenic concentrations. The burial age of the aquifer sediments, determined using optical stimulated luminescence, ranged from 460 years near the course of the present-day river to 5...

  14. The evolving use of arsenic in pharmacotherapy of malignant disease.

    Science.gov (United States)

    Kritharis, Athena; Bradley, Thomas P; Budman, Daniel R

    2013-06-01

    For more than 2,000 years, arsenic and its derivatives have shown medical utility. Owing to the toxicities and potential carcinogenicity of arsenicals, their popularity has fluctuated. The exact mechanism of action of therapeutic arsenic is not well characterized but likely to involve apoptosis, generation of reactive oxygen species, inhibition of intracellular transduction pathways, and cell functions. Arsenic trioxide has received approval for use in patients with relapsed acute promyelocytic leukemia for remission induction. Arsenic has additionally shown activity in a range of solid tumors, myelodysplastic syndrome, multiple myeloma, and in autoimmune diseases. The following is a review of the history of arsenic, its cellular metabolism, pharmacology, genetic basis of disposition, associated toxicities, and clinical efficacy. PMID:23494203

  15. Predicting groundwater arsenic contamination in Southeast Asia from surface parameters

    Science.gov (United States)

    Winkel, Lenny; Berg, Michael; Amini, Manouchehr; Hug, Stephan J.; Annette Johnson, C.

    2008-08-01

    Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Although many arsenic-affected areas have been identified in recent years, a systematic evaluation of vulnerable areas remains to be carried out. Here we present maps pinpointing areas at risk of groundwater arsenic concentrations exceeding 10μgl-1. These maps were produced by combining geological and surface soil parameters in a logistic regression model, calibrated with 1,756 aggregated and geo-referenced groundwater data points from the Bengal, Red River and Mekong deltas. We show that Holocene deltaic and organic-rich surface sediments are key indicators for arsenic risk areas and that the combination of surface parameters is a successful approach to predict groundwater arsenic contamination. Predictions are in good agreement with the known spatial distribution of arsenic contamination, and further indicate elevated risks in Sumatra and Myanmar, where no groundwater studies exist.

  16. A critical review of arsenic exposures for Bangladeshi adults.

    Science.gov (United States)

    Joseph, Tijo; Dubey, Brajesh; McBean, Edward A

    2015-09-15

    Groundwater, the most important source of water for drinking, cooking, and irrigation in Bangladesh, is a significant contributor to the daily human intake of arsenic. Other arsenic intake pathways, established as relevant for Bangladeshi adults through this review, include consumption of contaminated edible plant parts and animal-origin food, inhalation of contaminated air, soil ingestion, betel quid chewing, and tobacco smoking. This review qualifies and quantifies these arsenic intake pathways through analysis of the range of arsenic levels observed in different food types, water, soil, and air in Bangladesh, and highlights the contributions of dietary intake variation and cooking method in influencing arsenic exposures. This study also highlights the potential of desirable dietary patterns and intakes in increasing arsenic exposure which is relevant to Bangladesh where nutritional deficiencies and lower-than-desirable dietary intakes continue to be a major concern. PMID:26004539

  17. Diffuse parenchymal lung disease in a case of chronic arsenic exposure

    Directory of Open Access Journals (Sweden)

    Somnath Bhattacharya

    2016-01-01

    Full Text Available A 42-year-old housewife, the resident of rural part of West Bengal, presented with gradually progressive exertional dyspnea associated with a dry cough for last 3 years clinical features were suggestive of diffuse parenchymal lung disease (DPLD. Her chest X-ray posteroanterior view and high resolution computed tomography scan of the thorax showed bilateral patchy ground glass opacities and reticulonodular pattern. Search for the etiology revealed classical skin findings of chronic arsenic exposure in the form of generalized darkening and thickening of skin and keratotic lesions over the palms and soles and classical raindrop pigmentation over leg which was present for last 7 years subsequently her bronchoalveolar lavage fluid, hair, nail, and drinking water showed significant amount of arsenic contamination. By exclusion of all known causes of DPLD, we concluded that it was a case of DPLD due to chronic arsenic exposure. To the best of our knowledge, only few case report of DPLD in chronic arsenicosis has been reported till date.

  18. Aquifer Arsenic Cycling Induced by Seasonal Hydrologic Changes within the Yangtze River Basin.

    Science.gov (United States)

    Schaefer, Michael V; Ying, Samantha C; Benner, Shawn G; Duan, Yanhua; Wang, Yanxin; Fendorf, Scott

    2016-04-01

    Consumption of groundwater containing >10 μg L(-1) arsenic (As) adversely impacts more than 100 million people worldwide. Multiyear trends in aquifer As concentrations have been documented, but strong seasonal variations are not commonly observed. Here we report dramatic seasonal changes in As concentrations and aquifer chemistry within the Jianghan Plain of the Yangtze River, China. At some wells, concentrations fluctuate by more than an order of magnitude within a single year (100-1200 μg L(-1)). Groundwater extraction and sustained water levels of surface channels during the dry season induces a strong downward hydraulic gradient, seasonally supplying oxidizing (oxygen, nitrate) water to the otherwise anoxic aquifer. Oxygen and/or nitrate addition promotes a transient drop in As concentrations for 1-3 months. When recharge ceases, reducing, low-arsenic conditions are reestablished by reactive, endogenous organic carbon. Temporal variability in As concentrations is especially problematic because it increases the probability of false-negative well testing during low-arsenic seasons. However, periods of low As may also provide a source of less toxic water for irrigation or other uses. Our results highlight the vulnerability and variability of groundwater resources in the Jianghan Plain and other inland basins within Asia to changing geochemical conditions, both natural and anthropogenic, and reinforce that continued monitoring of wells in high-risk regions is essential. PMID:26788939

  19. Rice consumption contributes to arsenic exposure in US women

    OpenAIRE

    Gilbert-Diamond, Diane; Cottingham, Kathryn L.; Gruber, Joann F.; Punshon, Tracy; Sayarath, Vicki; Gandolfi, A. Jay; Baker, Emily R.; Jackson, Brian P.; Folt, Carol L; Margaret R Karagas

    2011-01-01

    Emerging data indicate that rice consumption may lead to potentially harmful arsenic exposure. However, few human data are available, and virtually none exist for vulnerable periods such as pregnancy. Here we document a positive association between rice consumption and urinary arsenic excretion, a biomarker of recent arsenic exposure, in 229 pregnant women. At a 6-mo prenatal visit, we collected a urine sample and 3-d dietary record for water, fish/seafood, and rice. We also tested women's ho...

  20. Analytical approaches for arsenic determination in air : a critical review

    OpenAIRE

    Sánchez-Rodas Navarro, Daniel Alejandro; Sánchez de la Campa Verdona, Ana María; Alsioufi, Louay

    2015-01-01

    This review describes the different steps involved in the determination of arsenic in air, considering the particulate matter (PM) and the gaseous phase. The review focuses on sampling, sample preparation and instrumental analytical techniques for both total arsenic determination and speciation analysis. The origin, concentration and legislation concerning arsenic in ambient air are also considered. The review intends to describe the procedures for sample collection of total suspended particl...

  1. The Role of Photochemistry the Transport and Transformation of Arsenic

    OpenAIRE

    Sedlak, David L.; Bentley, Abra

    1997-01-01

    Arsenic, a toxic trace element, enters surface waters from abandoned mines and geothermal springs. Once arsenic is discharged to surface waters, photochemical reactions can alter the oxidation state of the metal or cause the dissolution of the mineral phases onto which it could adsorb. To assess the role of these photochemical reactions arsenic fate and transport, we conducted laboratory studies and collected samples from arseniccontaminated surface waters. Results of laboratory studies indic...

  2. Resistance to Arsenic- and Antimony-Based Drugs

    OpenAIRE

    Milena Salerno; Arlette Garnier-Suillerot

    2003-01-01

    Organic arsenicals were the first antimicrobial agents specifically synthesized for the treatment of infectious diseases such as syphilis and sleeping sickness. For the treatment of diseases caused by trypanosomatid parasites, organic derivatives of arsenic and the related metalloid antimony are still the drugs of choice. Arsenic trioxide, As203, has been used for a long time in traditional Chinese medicines for treatment of various diseases, and it has recently been shown to be clinically ac...

  3. Arsenic geochemistry and human health in South East Asia

    OpenAIRE

    McCarty, Kathleen M.; Hanh, Hoang Thi; Kim, Kyoung-Woong

    2011-01-01

    Arsenic occurs naturally in many environmental components and enters the human body through several exposure pathways. Natural enrichment of arsenic may result in considerable contamination of soil, water, and air. Arsenic in groundwater can exceed values hundreds of time higher than the concentration recommended for drinking water. Such exposure levels indicate a serious potential health risk to individuals consuming raw groundwater. Human activities that have an impact on the environment ma...

  4. Quality of our groundwater resources: arsenic and fluoride

    Science.gov (United States)

    Nordstrom, D. Kirk

    2011-01-01

    Groundwater often contains arsenic or fluoride concentrations too high for drinking or cooking. These constituents, often naturally occurring, are not easy to remove. The right combination of natural or manmade conditions can lead to elevated arsenic or fluoride which includes continental source rocks, high alkalinity and pH, reducing conditions for arsenic, high phosphate, high temperature and high silica. Agencies responsible for safe drinking water should be aware of these conditions, be prepared to monitor, and treat if necessary.

  5. Purification of arsenic contaminated ground water using hydrated manganese dioxide

    International Nuclear Information System (INIS)

    An analytical methodology has been developed for the separation of arsenic from ground water using inorganic material in neutral medium. The separation procedure involves the quantitative retention of arsenic on hydrated manganese dioxide, in neutral medium. The validity of the separation procedure has been checked by a standard addition method and radiotracer studies. Neutron activation analysis (NAA), a powerful measurement technique, has been used for the quantitative determination of arsenic. (author)

  6. Alternative technology for arsenic removal from drinking water

    OpenAIRE

    Purenović Milovan

    2007-01-01

    Arsenic is a naturally occurring element in water, food and air. It is known as a poison, but in very small quantities it is showed to be an essential element. Actual problem in the world is arsenic removal from drinking water using modern and alternative technology, especially because EPA's and other international standards have reduced MCL from 50 to 10 ug/1. Because of rivers and lakes pollution, in a number of plants for natural water purification, average concentrations of arsenic in wat...

  7. Environmental Arsenic Exposure and Microbiota in Induced Sputum

    Directory of Open Access Journals (Sweden)

    Allison G. White

    2014-02-01

    Full Text Available Arsenic exposure from drinking water is associated with adverse respiratory outcomes, but it is unknown whether arsenic affects pulmonary microbiota. This exploratory study assessed the effect of exposure to arsenic in drinking water on bacterial diversity in the respiratory tract of non-smokers. Induced sputum was collected from 10 subjects with moderate mean household water arsenic concentration (21.1 ± 6.4 ppb and 10 subjects with low household water arsenic (2.4 ± 0.8 ppb. To assess microbiota in sputum, the V6 hypervariable region amplicons of bacterial 16s rRNA genes were sequenced using the Ion Torrent Personal Genome Machine. Microbial community differences between arsenic exposure groups were evaluated using QIIME and Metastats. A total of 3,920,441 sequence reads, ranging from 37,935 to 508,787 per sample for 316 chips after QIIME quality filtering, were taxonomically classified into 142 individual genera and five phyla. Firmicutes (22%, Proteobacteria (17% and Bacteriodetes (12% were the main phyla in all samples, with Neisseriaceae (15%, Prevotellaceae (12% and Veillonellacea (7% being most common at the genus level. Some genera, including Gemella, Lactobacillales, Streptococcus, Neisseria and Pasteurellaceae were elevated in the moderate arsenic exposure group, while Rothia, Prevotella, Prevotellaceae Fusobacterium and Neisseriaceae were decreased, although none of these differences was statistically significant. Future studies with more participants and a greater range of arsenic exposure are needed to further elucidate the effects of drinking water arsenic consumption on respiratory microbiota.

  8. Behavior of arsenic in hydrometallurgical zinc production and environmental impact

    OpenAIRE

    Peltekov A.B.; Boyanov B.S.; Markova T.S.

    2014-01-01

    The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS). In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5). In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine...

  9. GLI3 Links Environmental Arsenic Exposure and Human Fetal Growth

    Directory of Open Access Journals (Sweden)

    Emily F. Winterbottom

    2015-06-01

    Full Text Available Although considerable evidence suggests that in utero arsenic exposure affects children's health, these data are mainly from areas of the world where groundwater arsenic levels far exceed the World Health Organization limit of 10 μg/L. We, and others, have found that more common levels of in utero arsenic exposure may also impact children's health. However, the underlying molecular mechanisms are poorly understood. To address this issue, we analyzed the expression of key developmental genes in fetal placenta in a birth cohort of women using unregulated water supplies in a US region with elevated groundwater arsenic. We identified several genes whose expression associated with maternal arsenic exposure in a fetal sex-specific manner. In particular, expression of the HEDGEHOG pathway component, GLI3, in female placentae was both negatively associated with arsenic exposure and positively associated with infant birth weight. This suggests that modulation of GLI3 in the fetal placenta, and perhaps in other fetal tissues, contributes to arsenic's detrimental effects on fetal growth. We showed previously that arsenic-exposed NIH3T3 cells have reduced GLI3 repressor protein. Together, these studies identify GLI3 as a key signaling node that is affected by arsenic, mediating a subset of its effects on developmental signaling and fetal health.

  10. Arsenic-transforming microbes and their role in biomining processes.

    Science.gov (United States)

    Drewniak, L; Sklodowska, A

    2013-11-01

    It is well known that microorganisms can dissolve different minerals and use them as sources of nutrients and energy. The majority of rock minerals are rich in vital elements (e.g., P, Fe, S, Mg and Mo), but some may also contain toxic metals or metalloids, like arsenic. The toxicity of arsenic is disclosed after the dissolution of the mineral, which raises two important questions: (1) why do microorganisms dissolve arsenic-bearing minerals and release this metal into the environment in a toxic (also for themselves) form, and (2) How do these microorganisms cope with this toxic element? In this review, we summarize current knowledge about arsenic-transforming microbes and their role in biomining processes. Special consideration is given to studies that have increased our understanding of how microbial activities are linked to the biogeochemistry of arsenic, by examining (1) where and in which forms arsenic occurs in the mining environment, (2) microbial activity in the context of arsenic mineral dissolution and the mechanisms of arsenic resistance, (3) the minerals used and technologies applied in the biomining of arsenic, and (4) how microbes can be used to clean up post-mining environments. PMID:23299972

  11. Development of an arsenic trioxide vapor and arsine sampling train

    International Nuclear Information System (INIS)

    A sampling train was evaluated using 76As tracer for the measurement of particulate arsenic, arsine, and arsenic trioxide vapor in air and industrial process gas streams. In this train, a demister was used to remove droplets of water and oil, and particulates were removed by a filter. Vapor arsenic trioxide was collected in an impinger solution, and arsine gas was collected on silvered quartz beads. Hydrogen sulfide gas did not reduce the arsine trapping efficiency of the silvered beads, and charcoal proved to be an effective trap for both arsine and arsenic trioxide vapor. 1 figure, 2 tables

  12. Chemical characteristics of arsenic in a marine food chain

    International Nuclear Information System (INIS)

    The various chemical forms of 74As accumulated from either water or food by the marine food chain [Fucus spiralis (L.) → Littorina littoralis (L.) → Nucella lapillus] have been separated and characterized. Arsenic components were separated by differential extraction followed by high-voltage paper electrophoresis/paper chromatography of the water-soluble farction and thin-layer chromatography of the lipid-soluble fraction. The algae assimilates arsenic mainly (60%) as one lipid-soluble compound with Rsub(f) = 0.18, and 12 water-soluble organo-arsenic compounds as minor components. On the other hand, the snails produce predominantly one major water-soluble organo-arsenic compound with Rsub(f) = 0.66. This water-soluble arsenic compound was produced by the snails and not by intestinal microbes. Time-course studies on the relative proportions of labelled arsenic compounds in algal tissue indicate a transition from arsenate through water-soluble organo-arsenic components to a lipid-soluble arsenic compound. The water-soluble organo-arsenic compounds in the food chain studied were different from those previously found or proposed in marine organisms. (orig.)

  13. Environmental arsenic exposure, selenium and sputum alpha-1 antitrypsin

    DEFF Research Database (Denmark)

    Burgess, Jefferey L; Kurzius-Spencer, Margaret; Poplin, Gerald S;

    2014-01-01

    Exposure to arsenic in drinking water is associated with increased respiratory disease. Alpha-1 antitrypsin (AAT) protects the lung against tissue destruction. The objective of this study was to determine whether arsenic exposure is associated with changes in airway AAT concentration and whether...... selenium positively associated with sputum AAT (P=0.004 and P=0.002, respectively). In analyses stratified by town, these relationships remained significant only in Ajo, with the higher arsenic exposure. Reduction in AAT may be a means by which arsenic induces respiratory disease, and selenium may protect...

  14. Speciation of arsenic animal feed additives by microbore high-performance liquid chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Pergantis, S A; Heithmar, E M; Hinners, T A

    1997-10-01

    Phenylarsonic compounds have been used as poultry and swine feed additives for the purpose of growth promotion and disease prevention. Owing to the lack of suitable analytical methods, however, knowledge of their metabolism, environmental fate and impact remains incomplete. In order to compensate for this, analytical procedures were developed that allow the speciation of arsenic animal feed additives by using microbore high-performance liquid chromatography (microHPLC) coupled on-line with ICP-MS. More specifically, reversed-phase (RP) chromatographic methods were optimised to achieve the separation of various phenylarsonic acids from each other and from the more toxic inorganic arsenic compounds. This mode of chromatography, however, exhibits limitations, especially in the presence of naturally occurring organoarsenic compounds. The application of RP ion-pairing chromatography eliminates such shortcomings by minimising the co-elution of arsenic species. In general, the microHPLC-ICP-MS methods developed in this study provide high selectivity, extremely good sensitivity, low limits of detection (low-ppb or sub-pg amounts of As), require small sample volumes (< 1 microliter), minimise waste and operate most efficiently under low mobile-phase flow rates (15-40 microliters min-1), which are compatible for use with other types of mass spectrometers, e.g., electrospray. Reference materials containing naturally occurring arsenic compounds were spiked with phenylarsonic compounds and then analysed by using the procedures developed in this study. PMID:9463956

  15. ATL response to arsenic/interferon therapy is triggered by SUMO/PML/RNF4-dependent Tax degradation.

    Science.gov (United States)

    Dassouki, Zeina; Sahin, Umut; El Hajj, Hiba; Jollivet, Florence; Kfoury, Youmna; Lallemand-Breitenbach, Valérie; Hermine, Olivier; de Thé, Hugues; Bazarbachi, Ali

    2015-01-15

    The human T-cell lymphotropic virus type I (HTLV-1) Tax transactivator initiates transformation in adult T-cell leukemia/lymphoma (ATL), a highly aggressive chemotherapy-resistant malignancy. The arsenic/interferon combination, which triggers degradation of the Tax oncoprotein, selectively induces apoptosis of ATL cell lines and has significant clinical activity in Tax-driven murine ATL or human patients. However, the role of Tax loss in ATL response is disputed, and the molecular mechanisms driving degradation remain elusive. Here we demonstrate that ATL-derived or HTLV-1-transformed cells are dependent on continuous Tax expression, suggesting that Tax degradation underlies clinical responses to the arsenic/interferon combination. The latter enforces promyelocytic leukemia protein (PML) nuclear body (NB) formation and partner protein recruitment. In arsenic/interferon-treated HTLV-1 transformed or ATL cells, Tax is recruited onto NBs and undergoes PML-dependent hyper-sumoylation by small ubiquitin-like modifier (SUMO)2/3 but not SUMO1, ubiquitination by RNF4, and proteasome-dependent degradation. Thus, the arsenic/interferon combination clears ATL through degradation of its Tax driver, and this regimen could have broader therapeutic value by promoting degradation of other pathogenic sumoylated proteins. PMID:25395419

  16. Aerobic oxidation of mackinawite (FeS) and its environmental implication for arsenic mobilization

    Science.gov (United States)

    Jeong, Hoon Y.; Han, Young-Soo; Park, Sung W.; Hayes, Kim F.

    2010-06-01

    Oxidation of mackinawite (FeS) and concurrent mobilization of arsenic were investigated as a function of pH under oxidizing conditions. At acidic pH, FeS oxidation is mainly initiated by the proton-promoted dissolution, which results in the release of Fe(II) and sulfide in the solution. While most of dissolved sulfide is volatilized before being oxidized, dissolved Fe(II) is oxidized into green rust-like precipitates and goethite ( α-FeOOH). At basic pH, the development of Fe(III) (oxyhydr)oxide coating on the FeS surface inhibits the solution-phase oxidation following FeS dissolution. Instead, FeS is mostly oxidized into lepidocrocite ( γ-FeOOH) via the surface-mediated oxidation without dissolution. At neutral pH, FeS is oxidized via both the solution-phase oxidation following FeS dissolution and the surface-mediated oxidation mechanisms. The mobilization of arsenic during FeS oxidation is strongly affected by FeS oxidation mechanisms. At acidic pH (and to some extent at neutral pH), the rapid FeS dissolution and the slow precipitation of Fe (oxyhydr)oxides results in arsenic accumulation in water. In contrast, the surface-mediated oxidation of FeS at basic pH leads to the direct formation of Fe (oxyhydr)oxides, which provides effective adsorbents for As under oxic conditions. At acidic and neutral pH, the solution-phase oxidation of dissolved Fe(II) accelerates the oxidation of the less adsorbing As(III) to the more adsorbing As(V). This study reveals that the oxidative mobilization of As may be a significant pathway for arsenic enrichment of porewaters in sulfidic sediments.

  17. 植物根际促生菌的研究进展及其环境作用%Research Progress of Plant Growth-promoting Rhizobacteria and Its Environmental Effects

    Institute of Scientific and Technical Information of China (English)

    刘淑琮; 冯炘; 于洁

    2009-01-01

    具有固氮、溶磷、产生植物激素和分泌抗生素等功能的植物根际促生菌已成为新型生物肥料开发的研究热点.介绍了植物根际促生菌的定义、主要种类、作用机制、研究和应用现状.并提出绿色食品生产、资源再生利用要与植物根际促生菌生产相结合,促进绿色农业的发展,表明促生菌在经济与环境协调发展中具有重要的理论和现实意义.%Plant growth promoting rhizobacteria (PGPR) strain is a very important source for plant growth. It benefits plant by fixing nitrogen from air, as well as by solubilizing phosphate, producing phytohormones and antibiotic.The concept, main species and function mechanism of PGPR were introduced, and the research and application progress were reviewed as well. The combination of green food production, resources utilization and PGPR application makes great sense in theory and practice for economy development and environmental protection.

  18. Urinary arsenic speciation profile in ethnic group of the Atacama desert (Chile) exposed to variable arsenic levels in drinking water.

    Science.gov (United States)

    Yáñez, Jorge; Mansilla, Héctor D; Santander, I Paola; Fierro, Vladimir; Cornejo, Lorena; Barnes, Ramón M; Amarasiriwardena, Dulasiri

    2015-01-01

    Ethnic groups from the Atacama Desert (known as Atacameños) have been exposed to natural arsenic pollution for over 5000 years. This work presents an integral study that characterizes arsenic species in water used for human consumption. It also describes the metabolism and arsenic elimination through urine in a chronically exposed population in northern Chile. In this region, water contained total arsenic concentrations up to 1250 μg L(-1), which was almost exclusively As(V). It is also important that this water was ingested directly from natural water sources without any treatment. The ingested arsenic was extensively methylated. In urine 93% of the arsenic was found as methylated arsenic species, such as monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)]. The original ingested inorganic species [As(V)], represent less than 1% of the total urinary arsenic. Methylation activity among individuals can be assessed by measuring primary [inorganic As/methylated As] and secondary methylation [MMA/DMA] indexes. Both methylation indexes were 0.06, indicating a high biological converting capability of As(V) into MMA and then MMA into DMA, compared with the control population and other arsenic exposed populations previously reported. PMID:25438126

  19. New Sorbents for Removing Arsenic From Water

    Science.gov (United States)

    McConchie, D. M.; Genc-Fuhrman, H.; Clark, M. W.; Caldicott, W.; Davies-McConchie, F. G.

    2004-12-01

    Elevated concentrations of arsenic in the drinking water used in many countries, including some of the poorest developing countries, and recognition that consuming this water can have serious consequences for human health, have led to increased investigations of ways to obtain safe water supplies. Finding new groundwater resources is a possible solution but this is a costly strategy that has no guarantee of success, particularly in areas where water is already a scarce commodity. The alternative is to treat water that is already available, but existing technologies are usually too expensive, too difficult to operate and maintain, or not completely effective when used in less developed countries or remote areas. There is therefore, an urgent need to find a simple and effective but inexpensive sorbent for arsenic that can be used to treat large volumes of water under less than ideal conditions. In this paper we present the results of field and laboratory trials that used a new, highly cost-effective, sorbent to remove arsenic from contaminated water. BauxsolT is the name given to the cocktail of minerals prepared by treating caustic bauxite refinery residues with Mg and Ca to produce a substance with a reaction pH of about 8.5, a high acid neutralizing capacity and an excellent ability to trap trace metals, metalloids and some other ionic species. The trapped ions are tightly bound by processes that include; precipitation of low solubility neoformational minerals, isomorphous substitution, solid-state diffusion, and adsorption; it is also an excellent flocculant. Although ordinary BauxsolT has an excellent ability to bind arsenate, and to a lesser extent arsenite, this ability can be further increased for particular water types by using activated BauxsolT or BauxsolT combined with small amounts of other reagents. Field trials conducted at the Gilt Edge Mine, South Dakota, showed that the addition of BauxsolT to highly sulfidic waste rock reduced the arsenic

  20. Tropospheric arsenic over marine and continental regions

    International Nuclear Information System (INIS)

    Particulate and vapor concentrations of atmospheric As have been measured over various marine and continental areas. Particulate sample were collected on double Whatman 41 filters. Particulate-vapor samples were collected using an in-line filter system with a 0.45-μm pore size Nuclepore filters as a particle prefilter in front of two Whatman 41 filters impregnated with tetrabutylammonium hydroxide and glycerol for vapor As collection. Arsenic determinations were by destructive neutron activation. The data from the Nuclepore-impregnated filter samples indicates that the major fraction of As in the atmosphere is particulate but a vapor component of As is detectable, most frequently associated with high sampling temperatures and high total As concentrations. With the data presented here, estimates of representative global near-surface concentrations of atmospheric arsenic have been made

  1. Human Arsenic Poisoning Issues in Central-East Indian Locations: Biomarkers and Biochemical Monitoring

    Directory of Open Access Journals (Sweden)

    Madhurima Pandey

    2007-03-01

    Full Text Available The study reports the use of three biomarkers i.e. total arsenic in hair and nails, total arsenic in blood, and total arsenic in urine to identify or quantify arsenic exposure and concomitant health effects. The main source of arsenic was inorganic exposure through drinking water. The arsenic levels and the health effects were analyzed closely in a family having maximum symptoms of arsenic. Based on the result of this study it is reported that there exist a correlation between the clinically observable symptoms, the blood and urine arsenic level, and the arsenic intake through drinking water. An intensive study on the urinary arsenic levels was carried out in which the urine levels of arsenic and the urine sufficiency tests were performed. A composite picture of body burden of arsenic has been obtained by carrying out a complete biochemical analysis of a maximum affected family. This confirms pronounced chronic exposure of the arsenic to these people. A combined correlation study on the arsenic levels measured in whole blood, urine, hair, nails and age present a remarkable outcome. Accordingly, the arsenic levels in blood are negatively correlated with the urine arsenic levels, which indicate either the inadequacy of the renal system in cleaning the blood arsenic or a continuous recirculation of the accumulated arsenic. This is an important conclusion about arsenical metabolism in humans. The study also raises the issues of the prospects of complete elimination of the accumulated arsenic and the reversibility of the health effects. Based on the work in Kourikasa village we report that there are very remote chances of complete purging of arsenic and thus reversibility of the health effects owing to various factors. The paper also discusses the various issues concerning the chronic arsenic poisoning management in the affected locations.

  2. Health promotion for trachoma control

    OpenAIRE

    John Buchan; Anthony Solomon; Hannah Kuper; Marcia Zondervan

    2004-01-01

    Introduction Although progress has been made in refining the surgical and antibiotic components of the SAFE strategy, without effective health promotion it will be difficult to eliminate blinding trachoma by 2020. Health promotion is a cornerstone of each of the four components of the SAFE strategy. It includes: explaining the disease process and the need for trichiasis surgery to an often reluctant population (S) encouraging acceptance of mass antibiotic distribution (A) promoting ...

  3. Arsenic contamination of groundwater in Bangladesh

    International Nuclear Information System (INIS)

    Shallow groundwater with high arsenic concentrations from naturally occurring sources is the primary source of drinking water for millions of people in Bangladesh. It has resulted in a major public health crisis with as many as 70 million people possibly at risk. The International Atomic Energy Agency (IAEA) is supporting international efforts and the Government of Bangladesh to find alternative, safe and sustainable sources of drinking water. (IAEA)

  4. Arsenic toxicity: the effects on plant metabolism

    Directory of Open Access Journals (Sweden)

    PatrickFinnegan

    2012-06-01

    Full Text Available The two forms inorganic arsenic, arsenate (AsV and arsenite (AsIII, are easily taken up by the cells of the plant root. Once in the cell, AsV can be readily converted to AsIII, the more toxic of the two forms. AsV and AsIII both disrupt plant metabolism, but through distinct mechanisms. AsV is a chemical analogue of phosphate that can disrupt at least some phosphate-dependent aspects of metabolism. AsV can be translocated across cellular membranes by phosphate transport proteins, leading to imbalances in phosphate supply. It can compete with phosphate during phosphorylation reactions, leading to the formation of AsV adducts that are often unstable and short-lived. As an example, the formation and rapid autohydrolysis of AsV-ADP sets in place a futile cycle that uncouples photophosphorylation and oxidative phosphorylation, decreasing the ability of cells to produce ATP and carry out normal metabolism. AsIII is a dithiol reactive compound that binds to and potentially inactivates enzymes containing closely spaced cysteine residues or other sulfhydryl-containing groups. Arsenic exposure generally induces the production of reactive oxygen species that can lead to the production of antioxidant metabolites and numerous enzymes involved in antioxidant defense. Oxidative carbon metabolism, amino acid and protein relationships, and nitrogen and sulfur assimilation pathways are also impacted by As exposure. These effects are reflected in a dramatic restructuring of amino acid pools in Arabidopsis thaliana upon AsV exposure. Readjustment of several metabolic pathways, such as glutathione production, has been shown to lead to increased arsenic tolerance in plants. Species- and cultivar-dependent variation in arsenic sensitivity and the remodeling of metabolite pools that occurs in response to As exposure gives hope that additional metabolic pathways associated with As tolerance will be identified.

  5. Arsenic trioxide: safety issues and their management

    Institute of Scientific and Technical Information of China (English)

    Wing-Yan AU; Yok-Lam KWONG

    2008-01-01

    Arsenic trioxide (As2O3) has been used medicinally for thousands of years.Its therapeutic use in leukaemia was described a century ago.Recent rekindling in the interest of As2O3 is due to its high efficacy in acute promyelocytic leukaemia (APL).As2O3 has also been tested clinically in other blood and solid cancers.Most studies have used intravenous As2O3,although an oral As2O3 is equally efficacious.Side effects of As2O3 are usually minor,including skin reactions,gastrointestinal upset,and hepatitis.These respond to symptomatic treatment or temporary drug cessation,and do not compromise subsequent treatment with As2O3.During induction therapy in APL,a leucocytosis may occasionally occur,which can be associated with fluid accumulation and pulmonary infiltration.The condition is similar to the APL differentiation syndrome during treatment with all-trans retinoic acid,and responds to cytoreductive treatment and corticosteroids.Intravenous As2O3 treatment leads to QT prolongation.In the presence of under-lying cardiopulmonary diseases or electrolyte disturbances,particularly hypokalaemia and hypomagnesaemia,serious arrhythmias may develop,with torsades du pointes reported in 1% of cases.This may be related to a dose-dependent arsenic-mediated inhibition of potassium ion channels that compro-mises cardiac repolarization.Because of slow intestinal absorption,oral-As2O3 gives a lower plasma arsenic concentration,which is associated with lesser QT prolongation and hence a more favorable cardiac safety profile.As2O3 does not appear to enter the central nervous system.However,if the blood brain barrier is breached,elemental arsenic may enter the cerebrospinal fluid.As2O3 is predomi-nantly excreted in the kidneys,and dose adjustment is required when renal func-tion is impaired.

  6. Arsenic concentrations in groundwaters of Cyprus

    Science.gov (United States)

    Christodoulidou, M.; Charalambous, C.; Aletrari, M.; Nicolaidou Kanari, P.; Petronda, A.; Ward, N. I.

    2012-10-01

    SummaryCyprus being a Mediterranean island with long dry summers and mild winters suffers from water deficiency and over exploitation of its water resources. Groundwater in Cyprus is a valuable natural resource as approximately 50% of the total water needs come from underground water supplies. According to the Directive 118/2006/EC, groundwater should be protected from deterioration and chemical pollution, this is particularly important for groundwater dependent ecosystems and for the use of groundwater as a water supply for human consumption. During 2007 to 2009, as part of a national monitoring programme, 84 boreholes were sampled in Cyprus and subsequently analysed for total arsenic by inductively coupled plasma mass spectrometry (ICP-MS). The groundwater concentrations ranged from <0.3 to 41 μg/L As. Several boreholes located in a rural farming district near Nicosia had concentrations above the World Health Organisation (WHO) Drinking Water Guideline limit of 10 μg/L As. Evaluation of the groundwater sampling procedure for boreholes provided data recommending that water samples should be collected after an initial borehole washout for 5 min. Further sampling of these boreholes in 2010, revealed total arsenic concentrations of <0.3-64.2 μg/L As, with the predominant arsenic species (determined using a novel field-based methodology) being arsenate (AsV). The maximum total arsenic concentration is 6-fold higher than the WHO Drinking Water Guideline limit (10 μg/L As) and approximately half of the United Nations Food and Agriculture Organisation (UN-FAO) irrigational limit of 100 μg/L As.

  7. Arsenic evolution in fractured bedrock wells in central Maine, USA

    Science.gov (United States)

    Yang, Q.; Zheng, Y.; Culbertson, C.; Schalk, C.; Nielsen, M. G.; Marvinney, R.

    2010-12-01

    Elevated arsenic concentration in fractured bedrock wells has emerged as an important and challenging health problem, especially in rural areas without public water supply and mandatory monitoring of private wells. This has posed risks of skin, bladder, prostate diseases and cancers to private well users. In central Maine, including the study site, 31% of bedrock wells in meta-sedimentary formations have been reported of elevated arsenic concentrations of > 10 µg/L. Geophysical logging and fracture specific water sampling in high arsenic wells have been conducted to understand how water flowing through the aquifers enters the boreholes and how arsenic evolves in the fracture bedrock wells. Two domestic wells in Manchester, Maine, located 50 meter apart with 38 µg/L and 73 µg/L of arsenic in unfiltered water, were investigated to characterize fractures by geophysical logging and to determine flow rates by pumping test. Water samples, representing the bore hole and the fractures, were collected and analyzed for arsenic under ambient and pumping conditions. Transmissivity of the fractures was estimated at 0.23-10.6 m2/day. Water with high dissolved arsenic was supplied primarily by high yielding fractures near the bottom of the borehole. Dissolved arsenic concentrations in borehole water increased as fracture water with high arsenic was replacing borehole water with initially low dissolved arsenic in response to pumping. The precipitation of iron particulates enriched in arsenic was common during and after pumping. Laboratory experiment on well water samples over a period of 16 days suggested that in the borehole arsenic was mainly settled with iron enriched particles, likely amorphous ferric oxyhydroxides, with possibly minor adsorption on the iron minerals. Another bedrock well in Litchfield, Maine, with 478 µg/L of arsenic in the unfiltered well water, is being investigated to quantify and reconstruct of the groundwater flow under ambient and pumping conditions

  8. Arsenic speciation in arsenic-rich Brazilian soils from gold mining sites under anaerobic incubation

    Science.gov (United States)

    De Mello, J. W. V.; Talbott, J.L.; Scott, J.; Roy, W.R.; Stucki, J.W.

    2007-01-01

    Background. Arsenic speciation in environmental samples is essential for studying toxicity, mobility and bio-transformation of As in aquatic and terrestrial environments. Although the inorganic species As(III) and As(V) have been considered dominant in soils and sediments, organisms are able to metabolize inorganic forms of arsenic into organo-arsenic compounds. Arsenosugars and methylated As compounds can be found in terrestrial organisms, but they generally occur only as minor constituents. We investigated the dynamics of arsenic species under anaerobic conditions in soils surrounding gold mining areas from Minas Gerais State, Brazil to elucidate the arsenic biogeochemical cycle and water contamination mechanisms. Methods. Surface soil samples were collected at those sites, namely Paracatu Formation, Banded Iron Formation and Riacho dos Machados Sequence, and incubated in CaCl2 2.5 mmol L-1 suspensions under anaerobic conditions for 1, 28, 56 and 112 days. After that, suspensions were centrifuged and supernatants analyzed for soluble As species by IC-ICPMS and HPLC-ICPMS. Results. Easily exchangeable As was mainly arsenite, except when reducible manganese was present. Arsenate was mainly responsible for the increase in soluble arsenic due to the reductive dissolution of either iron or manganese in samples from the Paracatu Formation and Riacho dos Machados Sequence. On the other hand, organic species of As dominated in samples from the Banded Iron Formation during anaerobic incubation. Discussion. Results are contrary to the expectation that, in anaerobic environments, As release due to the reductive dissolution of Fe is followed by As(V) reduction to As(III). The occurrence of organo-arsenic species was also found to be significant to the dynamics of soluble arsenic, mainly in soils from the Banded Iron Formation (BIF), under our experimental conditions. Conclusions. In general, As(V) and organic As were the dominant species in solution, which is surprising

  9. Atorvastatin acts synergistically with N-acetyl cysteine to provide therapeutic advantage against Fas-activated erythrocyte apoptosis during chronic arsenic exposure in rats

    International Nuclear Information System (INIS)

    Arsenic is an environmental toxicant that reduces the lifespan of circulating erythrocytes during chronic exposure. Our previous studies had indicated involvement of hypercholesterolemia and reactive oxygen species (ROS) in arsenic-induced apoptotic death of erythrocytes. In this study, we have shown an effective recovery from arsenic-induced death signaling in erythrocytes in response to treatment with atorvastatin (ATV) and N-acetyl cysteine (NAC) in rats. Our results emphasized on the importance of cholesterol in the promotion of ROS-mediated Fas signaling in red cells. Arsenic-induced activation of caspase 3 was associated with phosphatidylserine exposure on the cell surface and microvesiculation of erythrocyte membrane. Administration of NAC in combination with ATV, proved to be more effective than either of the drugs alone towards the rectification of arsenic-mediated disorganization of membrane structural integrity, and this could be linked with decreased ROS accumulation through reduced glutathione (GSH) repletion along with cholesterol depletion. Moreover, activation of caspase 3 was capable of promoting aggregation of band 3 with subsequent binding of autologous IgG and opsonization by C3b that led to phagocytosis of the exposed cells by the macrophages. NAC-ATV treatment successfully amended these events and restored lifespan of erythrocytes from the exposed animals almost to the control level. This work helped us to identify intracellular membrane cholesterol enrichment and GSH depletion as the key regulatory points in arsenic-mediated erythrocyte destruction and suggested a therapeutic strategy against Fas-activated cell death related to enhanced cholesterol and accumulation of ROS.

  10. Sedimentology and arsenic pollution in the Bengal Basin: insight into arsenic occurrence and subsurface geology.

    Science.gov (United States)

    Hills, Andrew; McArthur, John

    2014-05-01

    The Bengal delta system is a geologically recent feature overlying a deeply incised palaeo-surface formed during the Last Glacial Maximum. This surface is a series of terraces and valleys created by river incision (Goodbred & Kuehl 2003). The terraces were weathered, forming a thin, indurated laterite deposit (Goodbred & Kuehl 2000) at depths greater than 50 m. McArthur et al. (2008) define this as a palaeosol and have identified it at depths greater than 30 m though out Bangladesh and West Bengal. It has been observed that arsenic concentrations at these sites are lower than the rest of the delta. It has been assumed that the surface morphology at sites where there is a palaeosol are similar and can therefore be characterised by remote sensing, in the form of Google Earth images. Sites were selected in Bangladesh and West Bengal, from work by McArthur et al. (2011); Hoque et al. (2012), where groundwater chemistry and sedimentology data are available making it possible to determine if the subsurface is a palaeo-channel or palaeo-interfluve. Arsenic concentration data have been inputted into Google Earth and the palaeo-channels marked where the arsenic concentration is greater than 10 µg/L, and palaeo-interfluves where arsenic concentration is less than 10 µg/L. The surface morphologies in these domains have been examined for similarities, and it was shown that avulsion scars and abandoned river channels are found where arsenic concentrations are greater than 10 µg/L. Conversely the surrounding areas that are devoid of channel scars have arsenic concentrations less than 10 µg/L. Using the correlation between avulsion features being representative of palaeo-channels and high arsenic concentrations, sites were selected that had a similar surface morphology to the type localities. A comparison of these images and arsenic concentrations showed that the postulate is valid for over 80 percent of cases. Where this is not valid, this could indicate that the subsurface

  11. Natural and industrial Arsenic pollution,early predictors of cardiovascular disease

    OpenAIRE

    Bianchi, Fabrizio

    2012-01-01

    Inorganic arsenic and arsenic compounds have been classidied in Group 1 " carcinogenic to humans" by IARC (2004). Both short-and long-term exposure to arsenic can cause several health problems. The interest in cardiovascular effects of human esposures to arsenic is growing.

  12. ACCELERATED SOLVENT EXTRACTION OF ARSENICALS FROM SEAFOOD MATRICES WITH ION CHROMATOGRAPHY AND ICP-MS DETECTION

    Science.gov (United States)

    The two major sources of arsenic exposure are water and diet. Dietary exposure is considerably more difficult to assess because of the diversity of arsenicals present in dietary matrices coupled with species dependent toxicity of arsenic. Dietary arsenic assessments are further c...

  13. PEPTIDE BINDING AS A MODE OF ACTION FOR THE CARCINOGENICITY AND TOXICITY OF ARSENIC

    Science.gov (United States)

    Arsenic exposure leads to tumors in human skin, lung, urinary bladder, kidney and liver. Three likely initial stages of arsenical-macromolecular interaction are (1) binding of trivalent arsenicals to the sulfhydryl groups of peptides and proteins, (2) arsenical-induced generation...

  14. Subsurface iron and arsenic removal for drinking water treatment in Bangladesh

    NARCIS (Netherlands)

    Van Halem, D.

    2011-01-01

    Arsenic contamination of shallow tube well drinking water is an urgent health problem in Bangladesh. Current arsenic mitigation solutions, including (household) arsenic removal options, do not always provide a sustainable alternative for safe drinking water. A novel technology, Subsurface Arsenic Re

  15. Interactions of arsenic and phenanthrene on their uptake and antioxidative response in Pteris vittata L

    Energy Technology Data Exchange (ETDEWEB)

    Sun Lu [Beijing Key Lab of Industrial Land Contamination and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Yan Xiulan [Beijing Key Lab of Industrial Land Contamination and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101 (China); Liao Xiaoyong, E-mail: liaoxy@igsnrr.ac.cn [Beijing Key Lab of Industrial Land Contamination and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101 (China); Wen Yi; Chong Zhongyi; Liang Tao [Beijing Key Lab of Industrial Land Contamination and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101 (China)

    2011-12-15

    The interactions of arsenic and phenanthrene on plant uptake and antioxidative response of Pteris vitatta L. were studied hydroponically. The combination of arsenic and phenanthrene decreased arsenic contents in fronds by 30-51%, whereas increased arsenic concentrations 1.2-1.6 times in roots, demonstrating the suppression of arsenic translocation compared to the corresponding treatment without phenanthrene. Under the co-exposure, As(III) concentrations in fronds deceased by 12-73%, and at higher arsenic exposure level ({>=}10 mg/L), As(V) in fronds and As(III) in roots increased compared to the single arsenic treatment. Arsenic exposure elevated phenanthrene concentrations in root by 39-164%. The co-existence of arsenic and phenanthrene had little impact on plant arsenic accumulation, although synergistic effect on antioxidants was observed, suggesting the special physiological process of P. vitatta in the co-exposure and application potential of P. vitatta in phytoremediation of arsenic and PAHs co-contamination. - Highlights: > Pteris vitatta L. show tolerance to the arsenic and phenanthrene co-exposure. > P. vitatta efficiently accumulate arsenic and simultaneously enhance phenanthrene dissipation. > Phenanthrene suppresses arsenic translocation from roots to fronds. > Phenanthrene causes As(III) elevation in roots while reduction in fronds. > Synergistic effect potentiates the toxicity and antioxidants in plant. - Pteris vitatta L. not only efficiently accumulate arsenic but also enhance phenanthrene dissipation under the arsenic and phenanthrene co-exposure.

  16. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium.

    Science.gov (United States)

    Maizel, Daniela; Utturkar, Sagar M; Brown, Steven D; Ferrero, Marcela A; Rosen, Barry P

    2015-01-01

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8. PMID:25883298

  17. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium

    OpenAIRE

    Maizel, Daniela; Utturkar, Sagar M.; Brown, Steven D.; Ferrero, Marcela A.; ROSEN, BARRY P.

    2015-01-01

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8.

  18. Effects of organic matter and ageing on the bioaccessibility of arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, Louise; Koch, Iris [Environmental Sciences Group, Royal Military College, P.O. Box 17 000, Station Forces, Kingston, Ontario K7K7B4 (Canada); Reimer, Kenneth J., E-mail: reimer-k@rmc.ca [Environmental Sciences Group, Royal Military College, P.O. Box 17 000, Station Forces, Kingston, Ontario K7K7B4 (Canada)

    2011-10-15

    Arsenic-contaminated soils may pose a risk to human health. Redevelopment of contaminated sites may involve amending soils with organic matter, which potentially increases arsenic bioaccessibility. The effects of ageing on arsenic-contaminated soils mixed with peat moss were evaluated in a simulated ageing period representing two years, during which arsenic bioaccessibility was periodically measured. Significant increases (p = 0.032) in bioaccessibility were observed for 15 of 31 samples tested, particularly in comparison with samples originally containing >30% bioaccessible arsenic in soils naturally rich in organic matter (>25%). Samples where percent arsenic bioaccessibility was unchanged with age were generally poor in organic matter (average 7.7%) and contained both arsenopyrite and pentavalent arsenic forms that remained unaffected by the organic matter amendments. Results suggest that the addition of organic matter may lead to increases in arsenic bioaccessibility, which warrants caution in the evaluation of risks associated with redevelopment of arsenic-contaminated land. - Highlights: > Adding organic matter to contaminated soils may increase arsenic bioaccessibility. > Ageing soils with >25% organic matter can lead to increased arsenic bioaccessibility. > No changes in arsenic bioaccessibility for soils poor in organic matter (mean 7.7%). > No changes in arsenic bioaccessibility for samples containing arsenopyrite. > Organic matter in soil may favour oxidation of trivalent arsenic to pentavalent form. - Adding organic carbon may increase arsenic bioaccessibility, especially in samples originally containing >30% bioaccessible arsenic in organic carbon-rich soils (>25%).

  19. Detecting and quantifying lewisite degradation products in environmental samples using arsenic speciation

    Energy Technology Data Exchange (ETDEWEB)

    Bass, D.A.; Yaeger, J.S.; Kiely, J.T.; Crain, J.S.; Shem, L.M.; O`Neill, H.J.; Gowdy, M.J. [Argonne National Lab., IL (United States); Besmer, M.; Mohrman, G.B. [Rocky Mountain Arsenal, Commerce City, CO (United States)

    1995-12-31

    This report describes a unique method for identifying and quantifying lewisite degradation products using arsenic (III) and arsenic (IV) speciation in solids and in solutions. Gas chromatographic methods, as well as high-performance liquid chromatographic methods are described for separation of arsenic species. Inductively coupled plasma-mass spectrographic methods are presented for the detection of arsenic.

  20. Secondary arsenic minerals in the environment: A review

    Czech Academy of Sciences Publication Activity Database

    Drahota, P.; Filippi, Michal

    2009-01-01

    Roč. 35, č. 8 (2009), s. 1243-1255. ISSN 0160-4120 R&D Projects: GA AV ČR KJB300130702 Institutional research plan: CEZ:AV0Z30130516 Keywords : arsenic * secondary arsenic mineral * environmental sample * solubility * environmental stability Subject RIV: DD - Geochemistry Impact factor: 4.786, year: 2009