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  Subjects -> ENVIRONMENTAL STUDIES (Total: 781 journals)
    - ENVIRONMENTAL STUDIES (717 journals)
    - POLLUTION (21 journals)
    - TOXICOLOGY AND ENVIRONMENTAL SAFETY (35 journals)
    - WASTE MANAGEMENT (8 journals)

ENVIRONMENTAL STUDIES (717 journals)            First | 1 2 3 4 5 6 7 8     

International Archives of Occupational and Environmental Health     Hybrid Journal   (Followers: 4)
International Environmental Agreements: Politics, Law and Economics     Hybrid Journal   (Followers: 10)
International Gambling Studies     Hybrid Journal   (Followers: 5)
International Innovation - climate     Open Access   (Followers: 1)
International innovation. Environment     Open Access  
International Journal of Acarology     Hybrid Journal   (Followers: 1)
International Journal of Advancement in Earth and Enviromental Sciences     Open Access   (Followers: 2)
International Journal of African Renaissance Studies - Multi-, Inter- and Transdisciplinarity     Hybrid Journal   (Followers: 2)
International Journal of Agricultural and Environmental Information Systems     Full-text available via subscription   (Followers: 2)
International Journal of Alternative Propulsion     Hybrid Journal   (Followers: 1)
International Journal of Applied Psychoanalytic Studies     Hybrid Journal   (Followers: 2)
International Journal of Chinese Culture and Management     Hybrid Journal   (Followers: 1)
International Journal of Corrosion     Open Access   (Followers: 10)
International Journal of Critical Infrastructures     Hybrid Journal   (Followers: 3)
International Journal of Disaster Risk Reduction     Hybrid Journal   (Followers: 6)
International Journal of Disaster Risk Science     Open Access   (Followers: 9)
International Journal of Ecological Economics and Statistics     Full-text available via subscription   (Followers: 1)
International Journal of Ecology     Open Access   (Followers: 8)
International Journal of Ecology & Development     Full-text available via subscription   (Followers: 1)
International Journal of Energy and Environmental Engineering     Open Access   (Followers: 2)
International Journal of Environment     Open Access   (Followers: 3)
International Journal of Environment and Health     Hybrid Journal   (Followers: 6)
International Journal of Environment and Pollution     Hybrid Journal   (Followers: 5)
International Journal of Environment and Sustainable Development     Hybrid Journal   (Followers: 15)
International Journal of Environment and Waste Management     Hybrid Journal   (Followers: 6)
International Journal of Environment, Workplace and Employment     Hybrid Journal   (Followers: 3)
International Journal of Environmental Engineering     Hybrid Journal   (Followers: 5)
International Journal of Environmental Health Engineering     Open Access  
International Journal of Environmental Health Research     Hybrid Journal   (Followers: 2)
International Journal of Environmental Policy and Decision Making     Hybrid Journal   (Followers: 10)
International Journal of Environmental Protection     Open Access   (Followers: 12)
International Journal of Environmental Research and Public Health     Open Access   (Followers: 15)
International Journal of Environmental Science and Technology     Hybrid Journal   (Followers: 5)
International Journal of Environmental Studies     Hybrid Journal   (Followers: 10)
International Journal of Exergy     Hybrid Journal   (Followers: 4)
International Journal of Forest, Soil and Erosion     Open Access   (Followers: 3)
International Journal of Global Environmental Issues     Hybrid Journal   (Followers: 4)
International Journal of Global Warming     Hybrid Journal   (Followers: 5)
International Journal of Greenhouse Gas Control     Partially Free   (Followers: 6)
International Journal of Health Planning and Management     Hybrid Journal   (Followers: 6)
International Journal of Hygiene and Environmental Health     Hybrid Journal   (Followers: 5)
International Journal of Logistics Research and Applications : A Leading Journal of Supply Chain Management     Hybrid Journal   (Followers: 9)
International Journal of Philosophical Studies     Hybrid Journal   (Followers: 2)
International Journal of Phytoremediation     Hybrid Journal   (Followers: 2)
International Journal of Process Systems Engineering     Hybrid Journal   (Followers: 1)
International Journal of Recycling of Organic Waste in Agriculture     Open Access   (Followers: 1)
International Journal of Regulation and Governance     Hybrid Journal   (Followers: 2)
International Journal of Reliability and Safety     Hybrid Journal   (Followers: 6)
International Journal of Renewable Energy Development     Open Access   (Followers: 6)
International Journal of Social Sciences and Management     Open Access  
International Journal of Soil, Sediment and Water     Open Access   (Followers: 8)
International Journal of Stress Management     Full-text available via subscription   (Followers: 9)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 7)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Materials and Structural Systems     Hybrid Journal   (Followers: 5)
International Journal of Sustainable Society     Hybrid Journal   (Followers: 7)
International Journal of Testing     Hybrid Journal   (Followers: 1)
International Journal of the Commons     Open Access   (Followers: 3)
International Journal of Toxicology     Hybrid Journal   (Followers: 6)
International Journal of Water Resources and Environmental Engineering     Open Access   (Followers: 1)
International Review of Environmental and Resource Economics     Full-text available via subscription  
International Studies in the Philosophy of Science     Hybrid Journal   (Followers: 9)
Interventions : International Journal of Postcolonial Studies     Hybrid Journal   (Followers: 9)
IOP Conference Series: Earth and Environmental Science     Open Access   (Followers: 7)
Iranian Studies     Hybrid Journal   (Followers: 9)
Irish Educational Studies     Hybrid Journal   (Followers: 2)
Irish Journal of Earth Sciences     Full-text available via subscription  
Irish Political Studies     Hybrid Journal   (Followers: 9)
ISLE: Interdisciplinary Studies in Literature and Environment     Hybrid Journal   (Followers: 1)
Isotopes in Environmental and Health Studies     Hybrid Journal   (Followers: 1)
Israel Studies     Full-text available via subscription   (Followers: 5)
ISRN Ecology     Open Access  
ISRN Environmental Chemistry     Open Access  
Jahangirnagar University Environmental Bulletin     Open Access  
Journal of Bioremediation & Biodegradation     Open Access   (Followers: 2)
Journal of Earth Science & Climatic Change     Open Access   (Followers: 8)
Journal of Petroleum & Environmental Biotechnology     Open Access   (Followers: 2)
Journal of Advanced Research in Civil and Environmental Engineering     Open Access  
Journal of Advances in Environmental Health Research     Open Access  
Journal of Agricultural and Environmental Ethics     Hybrid Journal   (Followers: 9)
Journal of Agricultural Biotechnology and Sustainable Development     Open Access  
Journal of Agricultural Chemistry and Environment     Open Access  
Journal of Agriculture and Environment     Open Access  
Journal of Agriculture and Environment for International Development     Open Access   (Followers: 5)
Journal of Agrobiology     Open Access   (Followers: 2)
Journal of Applied Ecology     Hybrid Journal   (Followers: 238)
Journal of Applied Meteorology and Climatology     Full-text available via subscription   (Followers: 8)
Journal of Applied Psychoanalytic Studies     Hybrid Journal   (Followers: 1)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 1)
Journal of Applied Sciences in Environmental Sanitation     Open Access   (Followers: 6)
Journal of Applied Toxicology     Hybrid Journal   (Followers: 9)
Journal of Applied Volcanology     Open Access   (Followers: 8)
Journal of Arid Environments     Hybrid Journal   (Followers: 8)
Journal of Asian Studies     Full-text available via subscription   (Followers: 24)
Journal of Biochemical and Molecular Toxicology     Hybrid Journal   (Followers: 4)
Journal of Black Studies     Hybrid Journal   (Followers: 2)
Journal of Chemical Ecology     Hybrid Journal   (Followers: 2)
Journal of Chemical Health and Safety     Hybrid Journal   (Followers: 2)
Journal of Climate     Full-text available via subscription   (Followers: 25)
Journal of Coastal Research     Full-text available via subscription   (Followers: 10)

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Journal Cover Journal of Applied Toxicology     [SJR: 0.689]   [H-I: 47]
   [11 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0260-437X - ISSN (Online) 1099-1263
   Published by John Wiley and Sons Homepage  [1605 journals]
  • Culture conditions profoundly impact phenotype in BEAS‐2B, a human
           pulmonary epithelial model
    • Authors: Fei Zhao; Walter T. Klimecki
      Pages: n/a - n/a
      Abstract: BEAS‐2B, an immortalized, human lung epithelial cell line, has been used to model pulmonary epithelial function for over 30 years. The BEAS‐2B phenotype can be modulated by culture conditions that include the presence or absence of fetal bovine serum (FBS). The popularity of BEAS‐2B as a model of arsenic toxicology, and the common use of BEAS‐2B cultured both with and without FBS, led us to investigate the impact of FBS on BEAS‐2B in the context of arsenic toxicology. Comparison of genome‐wide gene expression in BEAS‐2B cultured with or without FBS revealed altered expression in several biological pathways, including those related to carcinogenesis and energy metabolism. Real‐time measurements of oxygen consumption and glycolysis in BEAS‐2B demonstrated that FBS culture conditions were associated with a 1.4‐fold increase in total glycolytic capacity, a 1.9‐fold increase in basal respiration, a 2.0‐fold increase in oxygen consumed for ATP production and a 2.8‐fold increase in maximal respiration, compared with BEAS‐2B cultured without FBS. Comparisons of the transcriptome changes in BEAS‐2B resulting from FBS exposure to the transcriptome changes resulting from exposure to 1 μM sodium arsenite revealed that mRNA levels of 43% of the arsenite‐modulated genes were also modulated by FBS. Cytotoxicity studies revealed that BEAS‐2B cells exposed to 5% FBS for 8 weeks were almost 5 times more sensitive to arsenite cytotoxicity than non‐FBS‐exposed BEAS‐2B cells. Phenotype changes induced in BEAS‐2B by FBS suggest that culture conditions should be carefully considered when using BEAS‐2B as an experimental model of arsenic toxicity. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-12-19T00:27:35.684986-05:
      DOI: 10.1002/jat.3094
       
  • Ginsenoside Re protects methamphetamine‐induced mitochondrial
           burdens and proapoptosis via genetic inhibition of protein kinase C δ
           in human neuroblastoma dopaminergic SH‐SY5Y cell lines
    • Authors: Yunsung Nam; Myung Bok Wie, Eun‐Joo Shin, Thuy‐Ty Lan Nguyen, Seung‐Yeol Nah, Sung Kwon Ko, Ji Hoon Jeong, Choon‐Gon Jang, Hyoung‐Chun Kim
      Pages: n/a - n/a
      Abstract: Recently, we have demonstrated that ginsenoside Re protects methamphetamine (MA)‐induced dopaminergic toxicity in mice via genetic inhibition of PKCδ and attenuation of mitochondrial stress. In addition, we have reported that induction of mitochondrial glutathione peroxidase (GPx) is also important for neuroprotection mediated by ginsenoside Re. To extend our knowledge, we examined the effects of ginsenoside Re against MA toxicity in vitro condition using SH‐SY5Y neuroblastoma cells. Treatment with ginsenoside Re resulted in significant attenuations against a decrease in the activity of GPx and an increase in the activity of superoxide dismutase (SOD) in the cytosolic and mitochondrial fraction. The changes in glutathione (GSH) paralleled those in GPx in the same experimental condition. Consistently, ginsenoside Re treatment exhibited significant protections against cytosolic and mitochondrial oxidative damage (i.e. lipid peroxidation and protein oxidation), mitochondrial translocation of PKCδ, mitochondrial dysfunction (mitochondrial transmembrane potential and intra‐mitochondrial Ca2+), apoptotic events [i.e., cytochrome c release from mitochondria, cleavage of caspase‐3 and poly(ADP‐ribose)polymerase‐1, nuclear condensation, terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL)‐positive apoptotic cells], and a reduction in the tyrosine hydroxylase (TH) expression and TH activity induced by MA in SH‐SY5Y neuroblastoma cells. These protective effects of ginsenoside Re were comparable to those of PKCδ antisense oligonucleotide (ASO). However, ginsenoside Re did not significantly provide additional protective effects mediated by genetic inhibition of PKCδ. Our results suggest that PKCδ is a specific target for ginsenoside Re‐mediated protective activity against MA toxicity in SH‐SY5Y neuroblastoma cells. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-12-18T23:49:04.365172-05:
      DOI: 10.1002/jat.3093
       
  • Combined exposure to lead, inorganic mercury and methylmercury shows
           deviation from additivity for cardiovascular toxicity in rats
    • Authors: Tanja M. Wildemann; Lynn P. Weber, Steven D. Siciliano
      Pages: n/a - n/a
      Abstract: Environmental exposure to metal mixtures in the human population is common. Mixture risk assessments are often challenging because of a lack of suitable data on the relevant mixture. A growing number of studies show an association between lead or mercury exposure and cardiovascular effects. We investigated the cardiovascular effects of single metal exposure or co‐exposure to methylmercury [MeHg(I)], inorganic mercury [Hg(II)] and lead [Pb(II)]. Male Wistar rats received four different metal mixtures for 28 days through the drinking water. The ratios of the metals were based on reference and environmental exposure values. Blood and pulse pressure, cardiac output and electrical activity of the heart were selected as end‐points. While exposure to only MeHg(I) increased the systolic blood pressure and decreased cardiac output, the effects were reversed with combined exposures (antagonism). In contrast to these effects, combined exposures negatively affected the electrical activity of the heart (synergism). Thus, it appears that estimates of blood total Hg levels need to be paired with estimates of what species of mercury dominate exposure as well as whether lead co‐exposure is present to link total blood Hg levels to cardiovascular effects. Based on current human exposure data and our results, there may be an increased risk of cardiac events as a result of combined exposures to Hg(II), MeHg(I) and Pb(II). This increased risk needs to be clarified by analyzing lead and Hg exposure data in relation to cardiac electrical activity in epidemiological studies. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-12-18T23:16:46.75301-05:0
      DOI: 10.1002/jat.3092
       
  • HepaRG culture in tethered spheroids as an in vitro
           three‐dimensional model for drug safety screening
    • Authors: Zenan Wang; Xiaobei Luo, Chukwuemeka Anene‐Nzelu, Yu Yu, Xin Hong, Nisha Hari Singh, Lei Xia, Side Liu, Hanry Yu
      Abstract: Conventional two‐dimensional (2D) monolayer cultures of HepaRG cells allow in vitro maintenance of many liver‐specific functions. However, cellular dedifferentiation and functional deterioration over an extended culture period in the conventional 2D HepaRG culture have hampered its applications in drug testing. To address this issue, we developed tethered spheroids of HepaRG cells on Arg–Gly–Asp (RGD) and galactose‐conjugated substratum with an optimized hybrid ratio as an in vitro three‐dimensional (3D) human hepatocyte model. The liver‐specific gene expression level and drug metabolizing enzyme activities in HepaRG‐tethered spheorids were markedly higher than those in 2D cultures throughout the culture period of 7 days. The inducibility of three major cytochrome P450 (CYP) enzymes, namely CYP1A2, CYP2B6 and CYP3A4, was improved in both mRNA and activity level in tethered spheroids. Drug‐induced cytotoxic responses to model hepatotoxins (acetaminophen, chlorpromazine and ketoconazole) in tethered spheroids were comparable to 2D cultures as well as other studies in the literature. Our results suggested that the HepaRG‐tethered spheroid would be an alternative in vitro model suitable for drug safety screening. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-12-15T21:06:18.218232-05:
      DOI: 10.1002/jat.3090
       
  • Induction of the estrogen‐responsive genes encoding choriogenin H
           and L in the liver of male medaka (Oryzias latipes) upon exposure to
           estrogen receptor subtype‐selective ligands
    • Authors: Akemi Yamaguchi; Keisuke Kato, Koji Arizono, Nobuaki Tominaga
      Pages: n/a - n/a
      Abstract: Choriogenin (Chg) H and L are estrogen‐induced chorion precursors. We measured the induction of ChgH and ChgL mRNA in the livers of male medaka fish treated with Orthoester‐2k, a selective ligand for estrogen receptor (ER) α, and 2‐(4‐hydroxyphenyl)‐5‐hydroxy‐1,3‐benzoxazole (HPHB), a selective ligand of ERβ. Although both ChgH and ChgL mRNA were induced by treatment with Orthoester‐2k or HPHB separately, their combination induced much greater expression of each Chg. ChgH expression correlated more closely with Orthoester‐2k dosage when combined with a small fixed dose of HPHB (1 μm), whereas ChgL mRNA expression was more responsive to HPHB dose when combined with a fixed dose of Orthoester‐2k (2.8 nm). Moreover, upon long‐term treatment with Orthoester‐2k, ChgH mRNA and ERα mRNA expression showed similar patterns with peak expression between days 6 and 10. These results imply that ERβ primarily regulates ChgL mRNA expression and ERα action primarily regulates ChgH mRNA expression. Thus, it is necessary to develop screening methods for fish ER subtype‐specific ligands. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-12-10T08:14:40.91655-05:0
      DOI: 10.1002/jat.3063
       
  • Maternal exposure to 3,3’‐iminodipropionitrile targets
           late‐stage differentiation of hippocampal granule cell lineages to
           affect brain‐derived neurotrophic factor signaling and interneuron
           subpopulations in rat offspring
    • Authors: Megu Itahashi; Hajime Abe, Takeshi Tanaka, Sayaka Mizukami, Yoh Kikuchihara, Toshinori Yoshida, Makoto Shibutani
      Abstract: 3,3’‐Iminodipropionitrile (IDPN) causes neurofilament (NF)‐filled swellings in the proximal segments of many large‐caliber myelinated axons. This study investigated the effect of maternal exposure to IDPN on hippocampal neurogenesis in rat offspring using pregnant rats supplemented with 0 (controls), 67 or 200 ppm IDPN in drinking water from gestational day 6 to day 21 after delivery. On postnatal day (PND) 21, female offspring subjected to analysis had decreased parvalbumin+, reelin+ and phospho‐TrkB+ interneurons in the dentate hilus at 200 ppm and increased granule cell populations expressing immediate‐early gene products, Arc or c‐Fos, at ≥  67 ppm. mRNA expression in the dentate gyrus examined at 200 ppm decreased with brain‐derived neurotrophic factor (Bdnf) and very low density lipoprotein receptor. Immunoreactivity for phosphorylated NF heavy polypeptide decreased in the molecular layer of the dentate gyrus and the stratum radiatum of the cornu ammonis (CA) 3, portions showing axonal projections from mossy cells and pyramidal neurons, at 200 ppm on PND 21, whereas immunoreactivity for synaptophysin was unchanged in the dentate gyrus. Observed changes all disappeared on PND 77. There were no fluctuations in the numbers of apoptotic cells, proliferating cells and subpopulations of granule cell lineage in the subgranular zone on PND 21 and PND 77. Thus, maternal IDPN exposure may reversibly affect late‐stage differentiation of granule cell lineages involving neuronal plasticity as evident by immediate‐early gene responses to cause BDNF downregulation resulting in a reduction in parvalbumin+ or reelin+ interneurons and suppression of axonal plasticity in the mossy cells and CA3 pyramidal neurons. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-25T07:53:45.351994-05:
      DOI: 10.1002/jat.3086
       
  • Successful validation of genomic biomarkers for human immunotoxicity in
           Jurkat T cells in vitro
    • Authors: Peter C. J. Schmeits; Jia Shao, Danique A. Krieken, Oscar L. Volger, Henk Loveren, Ad. A. C. M. Peijnenburg, Peter J. M. Hendriksen
      Abstract: Previously, we identified 25 classifier genes that were able to assess immunotoxicity using human Jurkat T cells. The present study aimed to validate these classifiers. For that purpose, Jurkat cells were exposed for 6 h to subcytotoxic doses of nine immunotoxicants, five non‐immunotoxicants and four compounds for which human immunotoxicity has not yet been fully established. RNA was isolated and subjected to Fluidigm quantitative real time (qRT)–PCR analysis. The sensitivity, specificity and accuracy of the screening assay as based on the nine immunotoxicants and five non‐immunotoxicants used in this study were 100%, 80% and 93%, respectively, which is better than the performance in our previous study. Only one compound was classified as false positive (benzo‐e‐pyrene). Of the four potential (non‐)immunotoxicants, chlorantraniliprole and Hidrasec were classified immunotoxic and Sunset yellow and imidacloprid as non‐immunotoxic. ToxPi analysis of the PCR data provided insight in the molecular pathways that were affected by the compounds. The immunotoxicants 2,3‐dichloro‐propanol and cypermethrin, although structurally different, affected protein metabolism and cholesterol biosynthesis and transport. In addition, four compounds, i.e. chlorpyrifos, aldicarb, benzo‐e‐pyrene and anti‐CD3, affected genes in cholesterol metabolism and transport, protein metabolism and transcription regulation. qRT–PCR on eight additional genes coding for similar processes as defined in ToxPi analyzes, supported these results. In conclusion, the 25 immunotoxic classifiers performed very well in a screening with new non‐immunotoxic and immunotoxic compounds. Therefore, the Jurkat screening assay has great promise to be applied within a tiered approach for animal free testing of human immunotoxicity. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-25T07:38:41.511308-05:
      DOI: 10.1002/jat.3079
       
  • Experimentally induced, synergistic late effects of a single dose of
           radiation and aging: significance in LKS fraction as compared with mature
           blood cells
    • Authors: Yoko Hirabayashi; Isao Tsuboi, Kei Nakachi, Yoichiro Kusunoki, Tohru Inoue
      Abstract: The number of murine mature blood cells recovered within 6 weeks after 2‐Gy whole‐body irradiation at 6 weeks of age, whereas in the case of the undifferentiated hematopoietic stem/progenitor cell (HSC/HPC) compartment [cells in the lineage‐negative, c‐kit‐positive and stem‐cell‐antigen‐1‐positive (LKS) fraction], the numerical differences between mice with and without irradiation remained more than a year, but conclusively the cells showed numerical recovery. When mice were exposed to radiation at 6 months of age, acute damages of mature blood cells were rather milder probably because of their maturation with age; but again, cells in the LKS fraction were specifically damaged, and their numerical recovery was significantly delayed probably as a result of LKS‐specific cellular damages. Interestingly, in contrast to the recovery of the number of cells in the LKS fraction, their quality was not recovered, which was quantitatively assessed on the basis of oxidative‐stress‐related fluorescence intensity. To investigate why the recovery in the number of cells in the LKS fraction was delayed, expression levels of genes related to cellular proliferation and apoptosis of cells in the bone marrow and LKS fraction were analyzed by real‐time polymerase chain reaction (RT‐PCR). In the case of 21‐month‐old mice after radiation exposure, Ccnd1, PiK3r1 and Fyn were overexpressed solely in cells in the LKS fraction. Because Ccnd1and PiK3r1 upregulated by aging were further upregulated by radiation, single‐dose radiation seemed to induce the acceleration of aging, which is related to the essential biological responses during aging based on a lifetime‐dependent relationship between a living creature and xenobiotic materials. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-21T04:07:24.66173-05:0
      DOI: 10.1002/jat.3088
       
  • Surface‐expressed insulin receptors as well as IGF‐I receptors
           both contribute to the mitogenic effects of human insulin and its
           analogues
    • Authors: Anders Lundby; Pernille Bolvig, Anne Charlotte Hegelund, Bo F. Hansen, Jesper Worm, Anne Lützen, Nils Billestrup, Christine Bonnesen, Martin B. Oleksiewicz
      Abstract: There is a medical need for new insulin analogues. Yet, molecular alterations to the insulin molecule can theoretically result in analogues with carcinogenic effects. Preclinical carcinogenicity risk assessment for insulin analogues rests to a large extent on mitogenicity assays in cell lines. We therefore optimized mitogenicity assay conditions for a panel of five cell lines. All cell lines expressed insulin receptors (IR), IGF‐I receptors (IGF‐IR) and hybrid receptors, and in all cell lines, insulin as well as the comparator compounds X10 and IGF‐I caused phosphorylation of the IR as well as IGF‐IR. Insulin exhibited mitogenicity EC50 values in the single‐digit nanomolar to picomolar range. We observed correlations across cell types between (i) mitogenic potency of insulin and IGF‐IR/IR ratio, (ii) Akt phosphorylation and mitogenic potency and (iii) Akt phosphorylation and IR phosphorylation. Using siRNA‐mediated knockdown of IR and IGF‐IR, we observed that in HCT 116 cells the IR appeared dominant in driving the mitogenic response to insulin, whereas in MCF7 cells the IGF‐IR appeared dominant in driving the mitogenic response to insulin. Together, our results show that the IR as well as IGF‐IR may contribute to the mitogenic potency of insulin. While insulin was a more potent mitogen than IGF‐I in cells expressing more IR than IGF‐IR, the hyper‐mitogenic insulin analogue X10 was a more potent mitogen than insulin across all cell types, supporting that the hyper‐mitogenic effect of X10 involves the IR as well as the IGF‐IR. These results are relevant for preclinical safety assessment of developmental insulin analogues. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-21T03:01:09.888264-05:
      DOI: 10.1002/jat.3082
       
  • Tributyltin alters secretion of interleukin 1 beta from human immune cells
    • Authors: Shyretha Brown; Margaret Whalen
      Abstract: Tributyltin (TBT) has been used as a biocide in industrial applications such as wood preservation, antifouling paint and antifungal agents. Owing to its many uses, it contaminates the environment and has been found in human blood samples. Interleukin‐1 beta (IL‐1β) is a pro‐inflammatory cytokine that promotes cell growth, tissue repair and immune response regulation. Produced predominately by both monocytes and macrophages, IL‐1β appears to increase the invasiveness of certain tumors. This study shows that TBT modifies the secretion of IL‐1β from increasingly reconstituted preparations of human immune cells. IL‐1β secretion was examined after 24‐, 48‐h or 6‐day exposures to TBT in highly enriched human natural killer (NK) cells, monocyte‐depleted peripheral blood mononuclear cells (MD‐PBMCs), PBMCs, granulocytes and a preparation combining both PBMCs and granulocytes (PBMCs+granulocytes). TBT altered IL‐1β secretion from all of the cell preparations. The 200 nM concentration of TBT normally blocked the secretion of IL‐1β, whereas lower concentrations (usually 5–50 nM) elevated secretion of IL‐1β. Examination of the signaling pathway(s) responsible for the elevated secretion of IL‐1β was carried out in MD‐PBMCs. Pathways examined were IL‐1β processing (Caspase‐1), mitogen‐activated protein kinases (MAPKs) and nuclear factor kappa B (NFκB). Results indicated that MAPK pathways (p44/42 and p38) appear to be the targets of TBT that lead to increased IL‐1β secretion from immune cells. These results from human immune cells show IL‐1β dysregulation by TBT is occurring ex vivo. Thus, the potential for in vivo effects on pro‐inflammatory cytokine levels may possibly be a consequence of TBT exposures. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-07T22:41:26.682232-05:
      DOI: 10.1002/jat.3087
       
  • 2, 3, 7, 8‐Tetrachlorodibenzo‐p‐dioxin induces premature
           senescence of astrocytes via WNT/β‐catenin signaling and ROS
           production
    • Authors: Xiaoke Nie; Lingwei Liang, Hanqing Xi, Shengyang Jiang, Junkang Jiang, Cuiying Tang, Xipeng Liu, Suyi Liu, Chunhua Wan, Jianya Zhao, Jianbin Yang
      Abstract: 2, 3, 7, 8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is a ubiquitous environmental contaminant that could exert significant neurotoxicity in the human nervous system. Nevertheless, the molecular mechanism underlying TCDD‐mediated neurotoxicity has not been clarified clearly. Herein, we investigated the potential role of TCDD in facilitating premature senescence in astrocytes and the underlying molecular mechanisms. Using the senescence‐associated β‐galactosidase (SA‐β‐Gal) assay, we demonstrated that TCDD exposure triggered significant premature senescence of astrocyte cells, which was accompanied by a marked activation of the Wingless and int (WNT)/β‐catenin signaling pathway. In addition, TCDD altered the expression of senescence marker proteins, such as p16, p21 and GFAP, which together have been reported to be upregulated in aging astrocytes, in both dose‐ and time‐dependent manners. Further, TCDD led to cell‐cycle arrest, F‐actin reorganization and the accumulation of cellular reactive oxygen species (ROS). Moreover, the ROS scavenger N‐acetylcysteine (NAC) markedly attenuated TCDD‐induced ROS production, cellular oxidative damage and astrocyte senescence. Notably, the application of XAV939, an inhibitor of WNT/β‐catenin signaling pathway, ameliorated the effect of TCDD on cellular β‐catenin level, ROS production, cellular oxidative damage and premature senescence in astrocytes. In summary, our findings indicated that TCDD might induce astrocyte senescence via WNT/β‐catenin and ROS‐dependent mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-07T22:08:59.991905-05:
      DOI: 10.1002/jat.3084
       
  • Acute toxicity of 50 metals to Daphnia magna
    • Authors: Akira Okamoto; Masumi Yamamuro, Norihisa Tatarazako
      Abstract: Metals are essential for human life and physiological functions but may sometimes cause disorders. Therefore, we conducted acute toxicity testing of 50 metals in Daphnia magna: EC50s of seven elements (Be, Cu, Ag, Cd, Os, Au and Hg) were  100,000 µg l−1; and. 7 elements (Ti, Zr, Bi, Nb, Hf, Re and Ta) did not show EC50 at the upper limit of respective aqueous solubility, and EC50s were not obtained. Ga, Ru and Pd adhered to the body of D. magna and physically retarded the movement of D. magna. These metals formed hydroxides after adjusting the pH. Therefore, here, we distinguished this physical effect from the physiological toxic effect. The acute toxicity results of 40 elements obtained in this study were not correlated with electronegativity. Similarly, the acute toxicity results of metals including the rare metals were also not correlated with first ionization energy, atomic weight, atomic number, covalent radius, atomic radius or ionic radius. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-11-07T21:25:55.880885-05:
      DOI: 10.1002/jat.3078
       
  • RNA‐Seq‐based toxicogenomic assessment of fresh frozen and
           formalin‐fixed tissues yields similar mechanistic insights
    • Authors: Scott S. Auerbach; Dhiral P. Phadke, Deepak Mav, Stephanie Holmgren, Yuan Gao, Bin Xie, Joo Heon Shin, Ruchir R. Shah, B. Alex Merrick, Raymond R. Tice
      Abstract: Formalin‐fixed, paraffin‐embedded (FFPE) pathology specimens represent a potentially vast resource for transcriptomic‐based biomarker discovery. We present here a comparison of results from a whole transcriptome RNA‐Seq analysis of RNA extracted from fresh frozen and FFPE livers. The samples were derived from rats exposed to aflatoxin B1 (AFB1) and a corresponding set of control animals. Principal components analysis indicated that samples were separated in the two groups representing presence or absence of chemical exposure, both in fresh frozen and FFPE sample types. Sixty‐five percent of the differentially expressed transcripts (AFB1 vs. controls) in fresh frozen samples were also differentially expressed in FFPE samples (overlap significance: P 
      PubDate: 2014-11-06T04:16:58.370692-05:
      DOI: 10.1002/jat.3068
       
  • Impact of di‐ethylhexylphthalate exposure on metabolic programming
           in P19 ECC‐derived cardiomyocytes
    • Authors: Kristina Schaedlich; Juliane‐Susanne Schmidt, Wing Yee Kwong, Kevin D. Sinclair, Randy Kurz, Heinz‐Georg Jahnke, Bernd Fischer
      Abstract: Di(2‐ethylhexyl)phthalate (DEHP) is the most common plasticizer in plastic devices of everyday use. It is a ubiquitous environmental contaminant and primarily known to impair male gonadal development and fertility. Studies concerning the long‐term effects of prenatal DEHP exposure on certain diseases [The Developmental Origins of Health and Disease paradigm (DOHaD) hypothesis] are scarce although it is proven that DEHP crosses the placenta. Rising environmental pollution during the last centuries coincides with an increasing prevalence of cardiovascular and metabolic diseases. We have investigated the effects of an early embryonic DEHP exposure at different developmental stages on cardiomyogenesis. We used an in‐vitro model, the murine P19 embryonic carcinoma cell line (P19 ECC), mimicking early embryonic stages up to differentiated beating cardiomyocytes. P19 ECC were exposed to DEHP (5, 50, 100 µg ml–1) at the undifferentiated stage for 5 days and subsequently differentiated to beating cardiomyocytes. We analyzed the expression of metabolic (Pparg1, Fabp4 and Glut4), cardiac (Myh6, Gja1) and methylation (Dnmt1, Dnmt3a) marker genes by quantitative real‐time PCR (qRT‐PCR), beating rate and the differentiation velocity of the cells. The methylation status of Pparg1, Ppara and Glut4 was investigated by pyrosequencing. DEHP significantly altered the expression of all investigated genes. The beating rate and differentiation velocity were accelerated. Exposure to DEHP led to small but statistically significant increases in methylation of specific CpGs within Ppara and Pparg1, which otherwise were generally hypomethylated, but methylation of Glut4 was unaltered. Early DEHP exposure of P19 ECC alters the expression of genes associated with cellular metabolism and the functional features of cardiomyocytes. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-29T01:04:56.648549-05:
      DOI: 10.1002/jat.3085
       
  • Impacts of the feed contaminant deoxynivalenol on the intestine of
           monogastric animals: poultry and swine
    • Authors: Khaled Ghareeb; Wageha A. Awad, Josef Böhm, Qendrim Zebeli
      Abstract: Deoxynivalenol (DON) is one of the most prevalent cereal contaminants with major public health concerns owing to its high toxigenic potentials. Once ingested, DON first and foremost targets epithelial cells of the gastrointestinal tract, whose proper functioning, as the first line of defence, is of paramount importance for the host's health. Emerging evidences, summarized in this article, suggest that DON produces its toxicity primarily via activation of the mitogen‐activated protein kinases (MAPKs) signalling pathway and alteration in the expression of genes responsible for key physiological and immunological functions of the intestinal tissue of chickens and pigs. The activation of MAPKs signalling cascade results in disruption of the gut barrier function and an increase in the permeability by reducing expression of the tight junction proteins. Exposure to DON also down‐regulates the expression of multiple transporter systems in the enterocytes with subsequent impairment of the absorption of key nutrients. Other major intestinal cytotoxic effects of DON described herein are modulation of mucosal immune responses, leading to immunosupression or stimulation of local immune cells and cytokine release, and also facilitation of the persistence of intestinal pathogens in the gut. Both of the last events potentiate enteric infections and local inflammation in pigs and poultry, rendering enterocytes and the host more vulnerable to luminal toxic compounds. This review highlights the cytotoxic risks associated with the intake of even low levels of DON and also identifies gaps of knowledge that need to be addressed by future research. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-28T19:58:02.385342-05:
      DOI: 10.1002/jat.3083
       
  • Cellular uptake and toxicity effects of silver nanoparticles in mammalian
           kidney cells
    • Authors: Mirta Milić; Gerd Leitinger, Ivan Pavičić, Maja Zebić Avdičević, Slaven Dobrović, Walter Goessler, Ivana Vinković Vrček
      Abstract: The rapid progress and early commercial acceptance of silver‐based nanomaterials is owed to their biocidal activity. Besides embracing the antimicrobial potential of silver nanoparticles (AgNPs), it is imperative to give special attention to the potential adverse health effects of nanoparticles owing to prolonged exposure. Here, we report a detailed study on the in vitro interactions of citrate‐coated AgNPs with porcine kidney (Pk15) cells. As uncertainty remains whether biological/cellular responses to AgNPs are solely as a result of the release of silver ions or whether the AgNPs themselves have toxic effects, we investigated the effects of Ag+ on Pk15 cells for comparison. Next, we investigated the cellular uptake of both AgNPs and Ag+ in Pk15 cells at various concentrations applied. The detected Ag contents in cells exposed to 50 mg l−1 AgNPs and 50 mg l−1 Ag+ were 209 and 25 µg of Ag per 106 cells, respectively. Transmission electron microscopy (TEM) images indicated that the Pk15 cells internalized AgNPs by endocytosis. Both forms of silver, nano and ionic, decreased the number of viable Pk15 cells after 24 h in a dose‐dependent manner. In spite of a significant uptake into the cells, AgNPs had only insignificant toxicity at concentrations lower than 25 mg l−1, whereas Ag+ exhibited a significant decrease in cell viability at one‐fifth of this concentration. The Comet assay suggested that a rather high concentration of AgNP (above 25 mg l−1) is able to induce genotoxicity in Pk15 cells. Further studies must seek deeper understanding of AgNP behavior in biological media and their interactions with cellular membranes. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-28T19:21:35.91969-05:0
      DOI: 10.1002/jat.3081
       
  • Long‐term exposures to di‐n‐butyl phthalate inhibit body
           growth and impair gonad development in juvenile Murray rainbowfish
           (Melanotaenia fluviatilis)
    • Authors: Harpreet Bhatia; Anupama Kumar, John C. Chapman, Mike J. McLaughlin
      Abstract: The aim of the present study was to evaluate whether long‐term exposures to environmentally relevant concentrations of di‐n‐butyl phthalate (DnBP) disrupt the reproduction‐based endpoints in juvenile Murray rainbowfish (Melanotaenia fluviatilis). Fish were exposed to 5, 15 or 50 µg l−1 DnBP for 30, 60 and 90 days each, and the effects on survival, body growth, whole‐body concentrations of sex steroid hormones and gonadal development were investigated. The lowest observed effective concentration to affect the condition factor after 90 days was 5 µg l−1. Complete feminization of the gonad was noted in fish exposed to 5 µg l−1 for 90 days and to 15 and 50 µg l−1 of DnBP for 30 or 60 days. After 90 days of exposure to DnBP, the ovaries were regressed and immature as opposed to the control fish which were in early‐vitellogenic stage. Testes, present only in fish exposed to 5 µg l−1 of DnBP for 30 or 60 days, were immature in comparison to the control fish that contained testes in the mid‐spermatogenic phase. The E2/11‐KT ratio was significantly higher only after exposures to 5 µg l−1 DnBP for 90 days and 50 µg l−1 DnBP for 30 days. Our data suggest that exposures to 5 µg l−1 DnBP for 30 days did not have profound effects on body growth and gonadal differentiation of fish. However, 30 days of exposure to 15 µg l−1 could interfere with the gonad development and to 50 µg l−1 could compromise the hormonal profile of juvenile fish. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-28T01:12:32.140042-05:
      DOI: 10.1002/jat.3076
       
  • Organ‐specific distribution of gold nanoparticles by their surface
           functionalization
    • Authors: Jong Kwon Lee; Tae Sung Kim, Ji Young Bae, A. Young Jung, Sang Min Lee, Ji Hyun Seok, Hang Sik Roh, Chi Won Song, Mi Jin Choi, Jinyoung Jeong, Bong Hyun Chung, Yun‐Geon Lee, Jayoung Jeong, Wan‐Seob Cho
      Abstract: The behavior and fate of intravenously (i.v.) injected nanoparticles (NPs) can be controlled by several physicochemical factors including size, shape and surface charge. To evaluate the role of surface charge on distribution of NPs, we used neutral‐charged 15‐nm‐sized polyethylene glycol‐coated gold nanoparticles (AuNPPEG) as a core NP and carboxyl or amine groups were conjugated to AuNPPEG to generate negative (AuNPCOOH) or positive AuNP (AuNPNH2), respectively. Each type of AuNP was i.v. injected into mice (1 mg kg–1) and the concentration of Au was measured in different organs at 30 min, 4, 24 h, 7, 14 days, 1, 3 and 6 months post‐injection. The organ distribution also showed the higher deposition rate depending on their functional groups: AuNPPEG for mesenteric lymph node, kidney, brain and testis; AuNPCOOH for liver; AuNPNH2 for spleen, lung and heart. The blood circulation time and the major excretion route were different depending on their functional groups. In conclusion, functional groups conjugated on the surface of AuNPs produce differences in blood kinetics, organ distribution and elimination pattern which can be important information for directing NPs to specific organs or improving the kinetic properties. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-28T00:35:02.572138-05:
      DOI: 10.1002/jat.3075
       
  • Assessment of temperature‐induced hERG channel blockade variation by
           drugs
    • Authors: Rahul R. Kauthale; Shruta S. Dadarkar, Raghib Husain, Vikas V. Karande, Madhumanjiri M. Gatne
      Abstract: Drug‐induced QT prolongation has been reported in humans and animals. This potentially lethal effect can be induced by drugs interacting with a cardiac potassium channel, namely hERG (human ether‐a go‐go‐related gene) leading to arrhythmia or torsade de pointes (TdP). Hence, in vitro evaluation of therapeutics for their effects on the rapid delayed rectifier current (IKr) mediated by the K+ ion channel encoded by hERG is a valuable tool for identifying potential arrhythmic side effects during drug safety testing. Our objective was to evaluate the temperature‐induced hERG channel blockade variation by human and veterinary drugs using the IonFlux 16 system. A panel of eight drugs was tested for IKr inhibition at both ambient (23 °C) and physiological (37 °C) temperatures at various concentrations using IonFlux 16, an automated patch clamp system. Our results established that both amiodarone (IC50 = 0.56 μM at 23 °C and 0.30 μM at 37 °C) and β‐estradiol (IC50 = 24.72 μM at 23 °C and 8.17 μM at 37 °C) showed a dose‐dependent IKr blockade with a higher blockade at 37 °C. Whereas, blockade of IKr by both ivermectin (IC50 = 12.52 μM at 23 °C and 24.41 μM at 37 °C) and frusemide (IC50 = 12.58 μM at 23 °C and 25.55 μM at 37 °C) showed a dose‐dependent IKr blockade with a lower blockade at 37 °C. Gentamicin, enrofloxacin, xylazine and albendazole did not block IKr at both the assessed temperatures. Collectively, these results demonstrate that the effect of temperature variation should be taken into consideration during the evaluation of test drugs for their hERG channel blockade potential. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-28T00:14:26.431173-05:
      DOI: 10.1002/jat.3074
       
  • d‐α‐tocopheryl polyethylene glycol 1000
           succinate‐containing vehicles provide no detectable chemoprotection
           from oxidative damage
    • Authors: Bethany R. Baumgart; Terry R. Van Vleet, Damir Simic, Theodora W. Salcedo, Kimberley Lentz, Michael Donegan, Marc H. Davies, Roderick T. Bunch, Thomas P. Sanderson, Robert W. Lange
      Abstract: The objective of this study was to evaluate potential protective effects of vehicles containing d‐α‐tocopheryl polyethylene glycol 1000 succinate (TPGS), which may impact nonclinical safety assessments of oxidative processes. This was achieved by evaluating plasma, liver and adrenal gland concentrations of d‐α‐tocopheryl succinate (TS) and d‐α‐tocopherol as well as oxidative status of plasma following oral dosing of TPGS‐containing vehicles, intraperitoneal (IP) dosing of TS or ex vivo treatment of blood with H2O2. Male and female rats were dosed orally with formulations containing 5% or 40% TPGS (70 or 550 mg kg–1 day–1 TS, respectively) for 1 week. A control group was dosed orally with polyethylene glycol‐400 (PEG‐400; no vitamin E) and positive control animals received a single 100 mg kg–1 day–1 IP injection of TS. Whole blood from untreated animals was treated ex vivo with 5 or 50 mm H2O2, with or without TS (0.5, 5, 50 or 500 μm) or ascorbate (1 mm), for 1 h. Oral TPGS treatments did not affect d‐α‐tocopherol concentrations in plasma or adrenal glands and caused only transient increases in liver. Concentrations of TS in plasma, liver and adrenal glands were undetectable in control animals, but increased in all other groups. Oral administration of TPGS did not reduce plasma lipid peroxidation in vivo. Substantially greater TS concentrations used ex vivo (100× greater than in vivo) were also unable to reduce lipid peroxidation in H2O2‐treated whole blood. These results provide evidence that administration of oral TPGS vehicles is unlikely to impact nonclinical safety assessments of pharmaceuticals. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-27T23:54:17.450279-05:
      DOI: 10.1002/jat.3072
       
  • Comparison of the kinetics of various biomarkers of benzo[a]pyrene
           exposure following different routes of entry in rats
    • Authors: Marjory Moreau; Michèle Bouchard
      Abstract: The effect of route of exposure on the kinetics of key biomarkers of exposure to benzo[a]pyrene (BaP), a known human carcinogen, was studied. Rats were exposed to an intravenous, intratracheal, oral and cutaneous dose of 40 µmol kg–1 BaP. BaP and several metabolites were measured in blood, urine and feces collected at frequent intervals over 72 h post‐treatment, using high‐performance liquid chromatography/fluorescence. Only BaP and 3‐hydroxyBaP (3‐OHBaP) were detectable in blood at all time points. There were route‐to‐route differences in the excreted amounts (% dose) of metabolites but the observed time courses of the excretion rate were quite similar. In urine, total amounts of BaP metabolites excreted over the 0–72 h period followed the order: trans‐4,5‐dihydrodiolBaP (4,5‐diolBaP) ≥ 3‐OHBaP > 7‐OHBaP ≥ 7,8‐diolBaP after intravenous injection and intratracheal instillation; 3‐OHBaP ≈ 7‐OHBaP ≥ 4,5‐diolBaP > 7,8‐diolBaP after cutaneous application; 3‐OHBaP ≥ 4,5‐diolBaP ≈ 7‐OHBaP > 7,8‐diolBaP following oral administration. In feces, total amounts of BaP metabolites recovered were: 7‐OHBaP ≈ 3‐OHBaP > 4,5‐diolBaP > 7,8‐diolBaP > BaP‐7,8,9,10‐tetrol following all administration routes. For all exposure routes, excretion of 4,5‐ and 7,8‐diolBaP was almost complete over the 0–24 h period in contrast with that of 3‐ and 7‐OHBaP. This study confirms the interest of measuring multiple metabolites due to route‐to‐route differences in the relative excretion of the different biomarkers and in the time courses of diolBaPs versus OHBaPs. Concentration ratios of the different metabolites may help indicate time and main route of exposure. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-27T20:01:41.409244-05:
      DOI: 10.1002/jat.3070
       
  • Tween‐80 and impurity induce anaphylactoid reaction in zebrafish
    • Authors: Rui Yang; Qiao‐Cong Lao, Hang‐Ping Yu, Yong Zhang, Hong‐Cui Liu, Lin Luan, Hui‐Min Sun, Chun‐Qi Li
      Abstract: A number of recent reports suspected that Tween‐80 in injectable medicines, including traditional Chinese medicine injections could cause life‐threatening anaphylactoid reaction, but no sound conclusion was drawn. A drug‐induced anaphylactoid reaction is hard to be assayed in vitro and in conventional animal models. In this study, we developed a microplate‐based quantitative in vivo zebrafish assay for assessing anaphylactoid reaction and live whole zebrafish mast cell tryptase activity was quantitatively measured at a wavelength of 405 nm using N‐benzoyl‐dl‐arginine p‐nitroanilide as a substrate. We assessed 10 batches of Tween‐80 solutions from various national and international suppliers and three Tween‐80 impurities (ethylene glycol, 2‐chloroethanol and hydrogen peroxide) in this model and found that three batches of Tween‐80 (nos 2, 20080709 and 20080616) and one Tween‐80 impurity, hydrogen peroxide (H2O2), induced anaphylactoid reactions in zebrafish. Furthermore, we found that H2O2 residue and peroxide value were much higher in Tween‐80 samples 2, 20080709 and 20080616. These findings suggest that H2O2 residue in combination with oxidized fatty acid residues (measured as peroxide value) or more likely the oxidized fatty acid residues in Tween‐80 samples, but not Tween‐80 itself, may induce anaphylactoid reaction. High‐throughput zebrafish tryptase assay developed in this report could be used for assessing safety of Tween‐80‐containing injectable medicines and potentially for screening novel mast cell‐modulating drugs. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-27T02:05:30.018625-05:
      DOI: 10.1002/jat.3069
       
  • Mini review on blood–brain barrier penetration of pyridinium
           aldoximes
    • Authors: H. Kalász; S. M. Nurulain, G. Veress, S. Antus, F. Darvas, E. Adeghate, A. Adem, F. Hashemi, K. Tekes
      Pages: n/a - n/a
      Abstract: This paper reviews the blood–brain barrier (BBB) penetration of newly developed pyridinium aldoximes. Pyridinium aldoximes are highly charged hydrophilic compounds used in the treatment of subjects exposed to organophosphonates because they are effective as acetylcholinesterase reactivators. Pyridinium aldoximes have antidotal effects against poisoning with cholinesterase inhibitors, a frequent problem affecting people working with organophosphate‐based insecticides and pesticides. Toxic organophosphonate products such as sarin and tabun can be used by terrorists as chemical warfare agents. This poses a severe challenge to all innocent and peace‐loving people worldwide. This review gives a brief summary of BBB transporters and description of the current in vitro and in vivo methods for the characterization of BBB penetration of established and novel pyridinium aldoximes. The authors provide a putative mechanism of penetration, outline some future ways of formulation and discuss the possible advantages and disadvantages of increasing BBB penetration. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-10-07T05:21:33.385324-05:
      DOI: 10.1002/jat.3048
       
  • Neurotoxic effects of ochratoxin A on the subventricular zone of adult
           mouse brain
    • Authors: Sara Paradells; Brenda Rocamonde, Cristina Llinares, Vicente Herranz‐Pérez, Misericordia Jimenez, Jose Manuel Garcia‐Verdugo, Ivan Zipancic, Jose Miguel Soria, Ma. Angeles Garcia‐Esparza
      Abstract: Ochratoxin A (OTA), a mycotoxin that was discovered as a secondary metabolite of the fungal species Aspergillus and Penicillium, is a common contaminant in food and animal feed. This mycotoxin has been described as teratogenic, carcinogenic, genotoxic, immunotoxic and has been proven a potent neurotoxin. Other authors have previously reported the effects of OTA in different structures of the central nervous system as well as in some neurogenic regions. However, the impact of OTA exposure in the subventricular zone (SVZ) has not been assessed yet. To elucidate whether OTA affects neural precursors of the mouse SVZ we investigated, in vitro and in vivo, the effects of OTA exposure on the SVZ and on the neural precursors obtained from this neurogenic niche. In this work, we prove the cumulative effect of OTA exposure on proliferation, differentiation and depletion of neural stem cells cultured from the SVZ. In addition, we corroborated these results in vivo by immunohistochemistry and electron microscopy. As a result, we found a significant alteration in the proliferation process, which was evidenced by a decrease in the number of 5‐bromo‐2‐deoxyuridine‐positive cells and glial cells, as well as, a significant decrease in the number of neuroblasts in the SVZ. To summarize, in this study we demonstrate how OTA could be a threat to the developing and the adult SVZ through its impact in cell viability, proliferation and differentiation in a dose‐dependent manner. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-25T07:57:47.345347-05:
      DOI: 10.1002/jat.3061
       
  • Oral cadmium exposure during rat pregnancy: assessment of transplacental
           micronutrient transport and steroidogenesis at term
    • Authors: Anja Mikolić; Martina Piasek, Antonija Sulimanec Grgec, Veda M. Varnai, Sandra Stasenko, Saša Kralik Oguić
      Abstract: Diet is the main source of cadmium (Cd) exposure. Gastrointestinal absorption increases during pregnancy. Cadmium accumulated in the placenta may interfere with nutrient transport to the foetus. Data on the potential of Cd to act as a steroid disruptor of pregnancy are limited. We evaluated the effects of oral Cd exposure during pregnancy on placental function in micronutrient transfer to the foetus and steroidogenesis in Wistar rats (regular 4‐day cyclers) that mated with unexposed males. Pregnant rats were randomly assigned to a Cd group exposed orally to 50 mg Cd l–1 (CdCl2xH2O dissolved in demineralized water), ≈7.5 mg Cd kg–1 a day, during 20 days of gestation and control (supplied with demineralized water). Non‐pregnant rats were treated under the same experimental conditions. On day 20, all of the rats were killed and samples were taken for element analyses (by electrothermal atomic absorption spectrometry). Progesterone and testosterone were measured in serum and placenta‐derived samples (by immunoenzymometric assay and/or enzyme‐linked immunosorbent assay). In the exposed rats, Cd increased in blood and organs, more in pregnant rats, and in placenta and foetus whereas zinc increased in liver. Iron decreased in maternal organs and in foetus, whereas zinc decreased in maternal kidney and placenta. Liver copper was lower and kidney copper higher in all pregnant vs. non‐pregnant rats. Steroids in serum and placenta did not change. In conclusion, oral Cd exposure during rat pregnancy does not affect progesterone and testosterone at term. Transplacental iron and zinc handover are disrupted, which may put at risk the maintenance of foetal nutrition and viability. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-25T07:52:07.664676-05:
      DOI: 10.1002/jat.3055
       
  • Evaluation and refinement of a field‐portable drinking water
           toxicity sensor utilizing electric cell–substrate impedance sensing
           and a fluidic biochip
    • Authors: Mark W. Widder; Linda M. Brennan, Elizabeth A. Hanft, Mary E. Schrock, Ryan R. James, William H. Schalie
      Abstract: The US Army's need for a reliable and field‐portable drinking water toxicity sensor was the catalyst for the development and evaluation of an electric cell–substrate impedance sensing (ECIS) device. Water testing technologies currently available to soldiers in the field are analyte‐specific and have limited capabilities to detect broad‐based water toxicity. The ECIS sensor described here uses rainbow trout gill epithelial cells seeded on fluidic biochips to measure changes in impedance for the detection of possible chemical contamination of drinking water supplies. Chemicals selected for testing were chosen as representatives of a broad spectrum of toxic industrial compounds. Results of a US Environmental Protection Agency (USEPA)‐sponsored evaluation of the field portable device were similar to previously published US Army testing results of a laboratory‐based version of the same technology. Twelve of the 18 chemicals tested following USEPA Technology Testing and Evaluation Program procedures were detected by the ECIS sensor within 1 h at USEPA‐derived human lethal concentrations. To simplify field‐testing methods further, elimination of a procedural step that acclimated cells to serum‐free media streamlined the test process with only a slight loss of chemical sensitivity. For field use, the ECIS sensor will be used in conjunction with an enzyme‐based sensor that is responsive to carbamate and organophosphorus pesticides. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-18T03:31:57.64557-05:0
      DOI: 10.1002/jat.3017
       
  • Characteristic molecular and proteomic signatures of drug‐induced
           liver injury in a rat model
    • Authors: Jung Woo Eun; Hyun Jin Bae, Qingyu Shen, Se Jin Park, Hyung Seok Kim, Woo Chan Shin, Hee Doo Yang, Chan Young Jin, Jueng Soo You, Hyun Joo Kang, Hoguen Kim, Young Min Ahn, Won Sang Park, Jung Young Lee, Suk Woo Nam
      Abstract: Drug‐induced liver injury (DILI) is a major safety concern during drug development and remains one of the main reasons for withdrawal of drugs from the market. Although it is crucial to develop methods that will detect potential hepatotoxicity of drug candidates as early and as quickly as possible, there is still a lack of sensitive and specific biomarkers for DILI that consequently leads to a scarcity of reliable hepatotoxic data. Hence, in this study, we assessed characteristic molecular signatures in rat liver treated with drugs (pyrazinamide, ranitidine, enalapril, carbamazepine and chlorpromazine) that are known to cause DILI in humans. Unsupervised hierarchical clustering analysis of transcriptome changes induced by DILI‐causing drugs resulted in three different subclusters on dendrogram, i.e., hepatocellular, cholestatic and mixed type of DILI at early time points (2 days), and multiclassification analysis suggested 31 genes as discernible markers for each DILI pattern. Further analysis for characteristic molecular signature of each DILI pattern provided a molecular basis for different modes of DILI action. A proteomics study of the same rat livers was used to confirm the results, and the two sets of data showed 60 matching classifiers. In conclusion, the data of different DILI‐causing drug treatments from genomic analysis in a rat model suggest that DILI‐specific molecular signatures can discriminate different patterns of DILI at an early exposure time point, and that they provide useful information for mechanistic studies that may lead to a better understanding of the molecular basis of DILI. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-18T03:11:37.586599-05:
      DOI: 10.1002/jat.3062
       
  • Chronic trimethyltin chloride exposure and the development of kidney
           stones in rats
    • Authors: Xuefeng Ren; Xin Wu, Gang Sui, Zhihong Gong, Emmanuel Yawson, Banghua Wu, Guanchao Lai, Xiaolin Ruan, Hongbin Gao, Feng Zhou, Bing Su, James R. Olson, Xiaojiang Tang
      Abstract: We recently reported that occupational exposure to trimethyltin (TMT) is a risk factor for developing kidney stones. To further examine the association between TMT exposure and the formation of kidney stones, we conducted a 180‐day animal study and exposed the randomly grouped Sprague–Dawley (SD) rats to TMT in the drinking water at doses of 0, 8.2, 32.8 and 131.3 µg kg–1 day–1. Transient behavioral changes were observed in the high‐dose group during the first 2 weeks of exposure. TMT exposure led to a significant dose‐dependent inhibition of renal H+/K+‐ATPase and an increase in urinary pH. In comparison to no kidney stones being identified in the control and the lowest dose group, 1 rat in the 32.8 µg kg–1 day–1 dose group and 3 out of 9 rats in the 131.3 µg kg–1 day–1 dose group were found to have stones in the kidney/urinary tract. Pathological analysis showed that more wide spread calcium disposition was observed in kidneys of rats with TMT exposure compared with the rats in the control group. However, X‐ray diffraction (XRD) analysis found that the kidney stones were mainly composed of struvite with the formula: NH4MgPO4 6H2O, while calcium‐containing components were also detected. Together, this study further demonstrates through animal studies that chronic exposure to a relatively low level of TMT induces nephrotoxicity and increases the risk for developing kidney stones. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-16T05:47:12.006379-05:
      DOI: 10.1002/jat.3054
       
  • Non‐clinical safety evaluation of single and repeated intramuscular
           administrations of MAGE‐A3 Cancer Immunotherapeutic in rabbits and
           cynomolgus monkeys
    • Authors: Eric Destexhe; Emilie Grosdidier, Nathalie Baudson, Roy Forster, Catherine Gerard, Nathalie Garçon, Lawrence Segal
      Abstract: The MAGE‐A3 recombinant protein combined with AS15 immunostimulant (MAGE‐A3 Cancer Immunotherapeutic) is under development by GlaxoSmithKline for the treatment of lung cancer and melanoma. We performed non‐clinical safety studies evaluating potential local and systemic toxic effects induced by MAGE‐A3 Cancer Immunotherapeutic in rabbits (study 1) and cynomolgus monkeys (study 2). Animals were allocated to two groups to receive a single (rabbits) or 25 repeated (every 2 weeks) injections (monkeys) of MAGE‐A3 Cancer Immunotherapeutic (treatment groups) or saline (control groups). All rabbits were sacrificed 3 days post‐injection and monkeys 3 days following last injection (3/5 per gender per group) or after a 3‐month treatment‐free period (2/5 per gender per group). Local and systemic reactions and MAGE‐A3‐specific immune responses (monkeys) were assessed. Macroscopic and microscopic (for rabbits, injection site only) post‐mortem examinations were performed on all animals. No systemic toxicity or unscheduled mortalities were recorded. Single (rabbits) and repeated (monkeys; up to four times at the same site) injections were well tolerated. Following five to seven repeated injections, limb circumferences increased up to 26% (5 h post‐injection), but returned to normal after 1–8 days. Three days after the last injection, enlargements of iliac, popliteal, axillary and inguinal lymph nodes, and increased incidence or severity of mononuclear inflammatory cell infiltrates was observed in injected muscles of treated monkeys. No treatment‐related macroscopic findings were recorded after the treatment‐free period. MAGE‐A3‐specific antibody and T‐cell responses were raised in all treated monkeys, confirming test item exposure. Single or repeated intramuscular injections of MAGE‐A3 Cancer Immunotherapeutic were well tolerated in rabbits and monkeys. Copyright © 2014 GlaxoSmithKline Vaccines. Journal of Applied Toxicology published by John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T22:50:49.939421-05:
      DOI: 10.1002/jat.3025
       
  • Graphene supports in vitro proliferation and osteogenic differentiation of
           goat adult mesenchymal stem cells: potential for bone tissue engineering
    • Authors: Hoda Elkhenany; Lisa Amelse, Andersen Lafont, Shawn Bourdo, Marc Caldwell, Nancy Neilsen, Enkeleda Dervishi, Oshin Derek, Alexandru S. Biris, David Anderson, Madhu Dhar
      Abstract: Current treatments for bone loss injuries involve autologous and allogenic bone grafts, metal alloys and ceramics. Although these therapies have proved useful, they suffer from inherent challenges, and hence, an adequate bone replacement therapy has not yet been found. We hypothesize that graphene may be a useful nanoscaffold for mesenchymal stem cells and will promote proliferation and differentiation into bone progenitor cells. In this study, we evaluate graphene, a biocompatible inert nanomaterial, for its effect on in vitro growth and differentiation of goat adult mesenchymal stem cells. Cell proliferation and differentiation are compared between polystyrene‐coated tissue culture plates and graphene‐coated plates. Graphitic materials are cytocompatible and support cell adhesion and proliferation. Importantly, cells seeded on to oxidized graphene films undergo osteogenic differentiation in fetal bovine serum‐containing medium without the addition of any glucocorticoid or specific growth factors. These findings support graphene's potential to act as an osteoinducer and a vehicle to deliver mesenchymal stem cells, and suggest that the combination of graphene and goat mesenchymal stem cells provides a promising construct for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T22:12:52.239351-05:
      DOI: 10.1002/jat.3024
       
  • Exposure to MnCl2 · 4H2O during development induces
           activation of microglial and perivascular macrophage populations in the
           hippocampal dentate gyrus of rats
    • Authors: Hajime Abe; Takumi Ohishi, Fumiyuki Nakane, Ayako Shiraki, Takeshi Tanaka, Toshinori Yoshida, Makoto Shibutani
      Abstract: Developmental exposure to Mn caused Mn accumulation in the brain tissue and transient disruption of granule cell neurogenesis, targeting the late stage differentiation of progenitor cells in the subgranular zone of the hippocampal dentate gyrus of rats. Because neurogenesis is influenced by proinflammatory responses, this study was performed to determine whether Mn exposure causes microglial activation in the dentate hilus, a region anatomically close to the subgranular zone of the dentate gyrus. Pregnant rats were treated with dietary MnCl2 · 4H2O at 32, 160 or 800 ppm from gestational day 10 to day 21 after delivery. An immunohistochemical analysis revealed increases in Iba1+ microglia in the hilus on postnatal day 21 following exposure to MnCl2 · 4H2O in a dose‐unrelated manner at 32 and at 800 ppm and an increase in CD163+ macrophage at 800 ppm in the hilus. Real‐time reverse transcription–polymerase chain reaction analysis revealed increases in the mRNA levels of Il1α, Il6, Nos2 and Tnf after 800 ppm MnCl2 · 4H2O. These results suggest that activation of microglia and perivascular macrophages occurs in the hilus after developmental exposure to MnCl2 · 4H2O at 800 ppm, and probably involves the disruption of neurogenesis through the accumulation of Mn in the brain tissue. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T22:06:33.032918-05:
      DOI: 10.1002/jat.3059
       
  • Cylindrospermopsin induces oxidative stress and genotoxic effects in the
           fish CLC cell line
    • Authors: Anna Sieroslawska; Anna Rymuszka
      Abstract: Cylindrospermopsin (CYN) is a cyanotoxin detected in water reservoirs worldwide. The toxin is a potent protein synthesis inhibitor capable of adversely influencing a wide range of cell functions. While data on the prooxidative potency of CYN are inconsistent, genotoxic effects towards certain mammalian cell types have been described. However, such a potential on fish cells has not yet been investigated. Hence, the aim of the study was to elucidate the prooxidative and genotoxic impact of CYN on a common carp (Cyprinus carpio L.) leucocyte cell line (CLC). The cells were incubated with the cyanotoxin at concentrations of 0.1, 0.5 or 1 µg ml–1. After 24 h, cytotoxic activity of CYN at the highest used concentration was confirmed by decreased cell membrane integrity and inhibited cell proliferation. Additionally, CYN at 0.5 and 1 µg ml–1 increased intracellular ATP levels and decreased the reduced to oxidized glutathione ratio. Furthermore, a significant increase in the reactive oxygen species (ROS) production with concomitant changes in superoxide dismutase activity was observed after a 3.5‐h exposure of the cells to the toxin. Genotoxic activity of CYN, manifested as oxidative DNA damage and elevated number of micronuclei, was also detected in exposed cells. The obtained results indicate that CYN is able to exert a wide range of adverse effects, including oxidative stress and genotoxicity in fish leucocytes. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T22:06:25.237034-05:
      DOI: 10.1002/jat.3040
       
  • Development of haemostatic decontaminants for the treatment of wounds
           contaminated with chemical warfare agents. 2: Evaluation of in vitro
           topical decontamination efficacy using undamaged skin
    • Authors: Christopher H. Dalton; Charlotte A. Hall, Helen L. Lydon, J. K. Chipman, John S. Graham, John Jenner, Robert P. Chilcott
      Abstract: The risk of penetrating, traumatic injury occurring in a chemically contaminated environment cannot be discounted. Should a traumatic injury be contaminated with a chemical warfare (CW) agent, it is likely that standard haemostatic treatment options would be complicated by the need to decontaminate the wound milieu. Thus, there is a need to develop haemostatic products that can simultaneously arrest haemorrhage and decontaminate CW agents. The purpose of this study was to evaluate a number of candidate haemostats for efficacy as skin decontaminants against three CW agents (soman, VX and sulphur mustard) using an in vitro diffusion cell containing undamaged pig skin. One haemostatic product (WoundStat™) was shown to be as effective as the standard military decontaminants Fuller's earth and M291 for the decontamination of all three CW agents. The most effective haemostatic agents were powder‐based and use fluid absorption as a mechanism of action to sequester CW agent (akin to the decontaminant Fuller's earth). The envisaged use of haemostatic decontaminants would be to decontaminate from within wounds and from damaged skin. Therefore, WoundStat™ should be subject to further evaluation using an in vitro model of damaged skin. Copyright © 2014 Crown copyright. Journal of Applied Toxicology © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T21:56:06.175164-05:
      DOI: 10.1002/jat.3060
       
  • Early chronic lead exposure reduces exploratory activity in young C57BL/6J
           mice
    • Authors: Mayra Gisel Flores‐Montoya; Christina Sobin
      Abstract: Research has suggested that chronic low‐level lead exposure diminishes neurocognitive function in children. Tests that are sensitive to behavioral effects at lowest levels of lead exposure are needed for the development of animal models. In this study we investigated the effects of chronic low‐level lead exposure on exploratory activity (unbaited nose poke task), exploratory ambulation (open field task) and motor coordination (Rotarod task) in pre‐adolescent mice. C57BL/6J pups were exposed to 0 ppm (controls), 30 ppm (low‐dose) or 230 ppm (high‐dose) lead acetate via dams’ drinking water administered from birth to postnatal day 28, to achieve a range of blood lead levels (BLLs) from not detectable to 14.84 µg dl–1). At postnatal day 28, mice completed behavioral testing and were killed (n = 61). BLLs were determined by inductively coupled plasma mass spectrometry. The effects of lead exposure on behavior were tested using generalized linear mixed model analyses with BLL, sex and the interaction as fixed effects, and litter as the random effect. BLL predicted decreased exploratory activity and no threshold of effect was apparent. As BLL increased, nose pokes decreased. The C57BL/6J mouse is a useful model for examining effects of early chronic low‐level lead exposure on behavior. In the C57BL/6J mouse, the unbaited nose poke task is sensitive to the effects of early chronic low‐level lead exposure. This is the first animal study to show behavioral effects in pre‐adolescent lead‐exposed mice with BLL below 5 µg dl–1. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-12T21:41:49.427385-05:
      DOI: 10.1002/jat.3064
       
  • Diagnostic and predictive performance and standardized threshold of
           traditional biomarkers for drug‐induced liver injury in rats
    • Authors: Yutaka Tonomura; Yuki Kato, Hiroyuki Hanafusa, Yuji Morikawa, Keigo Matsuyama, Takeki Uehara, Motonobu Ueno, Mikinori Torii
      Pages: n/a - n/a
      Abstract: Traditional biomarkers such as alanine and aspartate aminotransferase (ALT, AST) and total bilirubin (TBIL) have been widely used for detecting drug‐induced liver injury (DILI). Although the Food and Drug Administration (FDA) proposed standardized thresholds for human as Hy's law, those for animals have not been determined, and predictability of these biomarkers for future onset of hepatic lesions remains unclear. In this study, we investigated these diagnostic and predictive performance of 10 traditional biomarkers for liver injury by receiver‐operating characteristic (ROC) curve, using a free‐access database where 142 hepatotoxic or non‐hepatotoxic compounds were administrated to male rats (n = 5253). Standardization of each biomarker value was achieved by calculating the ratio to control mean value, and the thresholds were determined under the condition of permitting 5% false positive. Of these 10 biomarkers, AST showed the best diagnostic performance. Furthermore, ALT and TBIL also showed high performance under the situation of hepatocellular necrosis and bile duct injury, respectively. Additionally, the availability of the diagnostic thresholds in difference testing facility was confirmed by the application of these thresholds to in‐house prepared dataset. Meanwhile, incorrect diagnosis by the thresholds was also observed. Regarding prediction, all 10 biomarkers showed insufficient performance for future onset of hepatic lesions. In conclusion, the standardized diagnostic thresholds enable consistent evaluation of traditional biomarkers among different facilities, whereas it was suggested that novel biomarker is required for more accurate diagnosis and prediction of DILI. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-04T05:02:30.374456-05:
      DOI: 10.1002/jat.3053
       
  • Perturbation of cytosolic calcium by 2‐aminoethoxydiphenyl borate
           and caffeine affects zebrafish myofibril alignment
    • Authors: Hsin‐Ju Wu; Tsorng‐Harn Fong, Shen‐Liang Chen, Jen‐Cheng Wei, I‐Jong Wang, Chi‐Chung Wen, Chao‐Yuan Chang, Xing‐Guang Chen, Wei‐Yu Chen, Hui‐Min Chen, Juin‐Lin Horng, Yun‐Hsin Wang, Yau‐Hung Chen
      Pages: n/a - n/a
      Abstract: The objective of the current study was to investigate the effects of Ca2+ levels on myofibril alignment during zebrafish embryogenesis. To investigate how altered cytoplasmic Ca2+ levels affect myofibril alignment, we exposed zebrafish embryos to 2‐aminothoxyldiphenyl borate (2‐APB; an inositol 1,4,5‐trisphosphate receptor inhibitor that reduces cytosolic Ca2+ levels) and caffeine (a ryanodine receptor activator that enhances cytosolic Ca2+ levels). The results demonstrated that the most evident changes in zebrafish embryos treated with 2‐APB were shorter body length, curved trunk and malformed somite boundary. In contrast, such malformed phenotypes were evident neither in untreated controls nor in caffeine‐treated embryos. Subtle morphological changes, including changes in muscle fibers, F‐actin and ultrastructures were easily observed by staining with specific monoclonal antibodies (F59 and α‐laminin), fluorescent probes (phalloidin) and by transmission electron microscopy. Our data suggested that: (1) the exposure to 2‐APB and/or caffeine led to myofibril misalignment; (2) 2‐APB‐treated embryos displayed split and short myofibril phenotypes, whereas muscle fibers from caffeine‐treated embryos were twisted and wavy; and (3) zebrafish embryos co‐exposed to 2‐APB and caffeine resulted in normal myofibril alignment. In conclusion, we proposed that cytosolic Ca2+ is important for myogenesis, particularly for myofibril alignment. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-04T04:56:51.010578-05:
      DOI: 10.1002/jat.3057
       
  • Skin absorption of six performance amines used in metalworking fluids
    • Authors: Lauriane N. Roux; James D. Brooks, James L. Yeatts, Ronald E. Baynes
      Pages: n/a - n/a
      Abstract: Every year, 10 million workers are exposed to metalworking fluids (MWFs) that may be toxic. There are four types of MWFs: neat oils and three water‐based MWFs (soluble oil, semisynthetic and synthetic), which are diluted with water and whose composition varies according to the mineral oils ratio. MWFs also contain various additives. To determine the absorption of six amines used as corrosion inhibitors and biocides in MWFs, porcine skin flow‐through diffusion cell experiments were conducted with hydrophilic ethanolamines (mono‐, di‐ and triethanolamine, MEA, DEA and TEA respectively) and a mixture of lipophilic amines (dibutylethanolamine, dicyclohexylamine and diphenylamine). The six amines were dosed in four vehicles (water and three generic water‐based MWF formulations) and analyzed using a scintillation counter or gas chromatography/mass spectrometry. These 24 h studies showed that dermal absorption significantly (P 
      PubDate: 2014-09-04T04:56:30.081537-05:
      DOI: 10.1002/jat.3056
       
  • A representative retinoid X receptor antagonist UVI3003 induced
           teratogenesis in zebrafish embryos
    • Authors: Liang Zheng; Ting Xu, Daoji Li, Junliang Zhou
      Pages: n/a - n/a
      Abstract: Retinoid X receptor (RXR) interfering activity has been detected in different water resources. To study RXR disruptor‐induced toxicological effects on vertebrates, embryos of zebrafish (Danio rerio) were exposed to a representative RXR antagonist UVI3003. Results showed that the teratogenic index (LC50/EC50) of UVI3003 was as high as 5.4. UVI3003 induced multiple malformations of embryos, including deformed fins, reduced brains, small jaws, bent tails and edema in hearts, the degree of which became more severe with increasing exposure concentration. Although no significant difference was observed in the hatching rates between the exposure group and control, the whole body length was significantly reduced by 6.5% and 8.9% when exposed to 200 and 300 µg l−1 of UVI3003, respectively. The heart rate also significantly decreased by 8.8–50.2% during exposure. Further experiments revealed that the pharyngula stage was the most sensitive development phase in terms of embryo response to UVI3003. The results demonstrated severe teratogenicity of RXR antagonist in zebrafish embryos and provided important data for ecotoxicological evaluation of RXR antagonists. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-03T03:07:21.862962-05:
      DOI: 10.1002/jat.3051
       
  • Immunophenotyping does not improve predictivity of the local lymph node
           assay in mice
    • Authors: Volker Strauss; Susanne N. Kolle, Naveed Honarvar, Martina Dammann, Sibylle Groeters, Frank Faulhammer, Robert Landsiedel, Bennard Ravenzwaay
      Pages: n/a - n/a
      Abstract: The local lymph node assay (LLNA) is a regulatory accepted test for the identification of skin sensitizing substances by measuring radioactive thymidine incorporation into the lymph node. However, there is evidence that LLNA is overestimating the sensitization potential of certain substance classes in particular those exerting skin irritation. Some reports describe the additional use of flow cytometry‐based immunophenotyping to better discriminate irritants from sensitizing irritants in LLNA. In the present study, the 22 performance standards plus 8 surfactants were assessed using the radioactive LLNA method. In addition, lymph node cells were immunophenotyped to evaluate the specificity of the lymph node response using cell surface markers such as B220 or CD19, CD3, CD4, CD8, I‐Aκ and CD69 with the aim to allow a better discrimination above all between irritants and sensitizers, but also non‐irritating sensitizers and non‐sensitizers. However, the markers assessed in this study do not sufficiently differentiate between irritants and irritant sensitizers and therefore did not improve the predictive capacity of the LLNA. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-03T03:06:12.16689-05:0
      DOI: 10.1002/jat.3042
       
  • Reversible cholinesterase inhibitors as pre‐treatment for exposure
           to organophosphates: assessment using azinphos‐methyl
    • Authors: Georg A. Petroianu; Syed M. Nurulain, Mohamed Y. Hasan, Kamil Kuča, Dietrich E. Lorke
      Pages: n/a - n/a
      Abstract: Pre‐treatment with reversible acetylcholinesterase (AChE) inhibitors before organophosphorous compound (OPC) exposure can reduce OPC‐induced mortality. However, pyridostigmine, the only substance employed for such prophylaxis, is merely efficacious against a limited number of OPCs. In search of more efficacious and broad‐range alternatives, we have compared in vivo the ability of five reversible AChE inhibitors (pyridostigmine, physostigmine, ranitidine, tacrine and K‐27) to reduce mortality induced by the OPC azinphos‐methyl. Protection was quantified using Cox analysis by determining the relative risk (RR) of death in rats that were administered these AChE inhibitors in equitoxic dosage (25% of LD01) 30 min before azinphos‐methyl exposure. Azinphos‐methyl‐induced mortality was significantly reduced by all five tested compounds as compared with the reference group that was only exposed to azinphos‐methyl without prior pre‐treatment (RR = 1). The most efficacious prophylactic agents were K‐27 (RR = 0.15) and physostigmine (RR = 0.21), being significantly more efficacious than ranitidine (RR = 0.62) and pyridostigmine (RR = 0.37). Pre‐treatment with tacrine (RR = 0.29) was significantly more efficacious than pre‐treatment with ranitidine, but the difference between tacrine and pyridostigmine was not significant. Our results indicate that prophylactic administration of the oxime K‐27 may be a promising alternative in cases of imminent OPC exposure. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-03T03:04:57.769676-05:
      DOI: 10.1002/jat.3052
       
  • Carnosic acid induces autophagic cell death through inhibition of the
           Akt/mTOR pathway in human hepatoma cells
    • Authors: Qilong Gao; Huaimin Liu, Yamin Yao, Liang Geng, Xinfeng Zhang, Lifeng Jiang, Bian Shi, Feng Yang
      Abstract: The therapeutic goal of cancer treatment is now geared towards triggering tumour‐selective cell death with autophagic cell death being required for the chemotherapy of apoptosis‐resistant cancer. In this study, Carnosic acid (CA), a polyphenolic diterpene isolated from Rosemary (Rosemarinus officinalis), significantly induced autophagic cell death in HepG2 cells. Ca treatment caused the formation of autophagic vacuoles produced an increasing ratio of LC3‐II to LC3‐I in a time‐ and dose‐dependent manner but had no effect on the levels of autophagy‐related protein ATG6 and ATG13 expression. Autophagy inhibitors, 3‐methyladenine (3‐MA), chloroquine and bafilomycin A1, or ATG genes silencing in HepG2 cells significantly inhibited CA‐induced autophagic cell death. The CA treatment decreased the levels of phosphorylated Akt and mTOR without any effects on PI3K or PTEN. Most importantly, overexpression of Akt and knockdown of PTEN attenuated autophagy induction in CA‐treated cells. Taken together, our results indicated that CA induced autophagic cell death through inhibition of the Akt/mTOR pathway in human hepatoma cells. These findings suggest that CA has a great potential for the treatment of hepatoma via autophagic induction. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-09-01T07:01:21.780556-05:
      DOI: 10.1002/jat.3049
       
  • Protective effects of ascorbic acid against the genetic and epigenetic
           alterations induced by 3,5‐dimethylaminophenol in AA8 cells
    • Authors: Ming‐Wei Chao; P𝚤nar Erkekoglu, Chia‐Yi Tseng, Wenjie Ye, Laura J. Trudel, Paul L. Skipper, Steven R. Tannenbaum, Gerald N. Wogan
      Abstract: Exposure to monocyclic aromatic alkylanilines (MAAs), namely 2,6‐dimethylaniline (2,6‐DMA), 3,5‐dimethylaniline (3,5‐DMA) and 3‐ethylaniline (3‐EA), was significantly and independently associated with bladder cancer incidence. 3,5‐DMAP (3,5‐dimethylaminophenol), a metabolite of 3,5‐DMA, was shown to induce an imbalance in cytotoxicity cellular antioxidant/oxidant status, and DNA damage in mammalian cell lines. This study was designed to evaluate the protective effect of ascorbic acid (Asc) against the cytotoxicity, reactive oxygen species (ROS) production, genotoxicity and epigenetic changes induced by 3,5‐DMAP in AA8 Chinese Hamster Ovary (CHO) cells. In different cellular fractions, 3,5‐DMAP caused alterations in the enzyme activities orchestrating a cellular antioxidant balance, decreases in reduced glutathione levels and a cellular redox ratio as well as increases in lipid peroxidation and protein oxidation. We also suggest that the cellular stress caused by this particular alkylaniline leads to both genetic (Aprt mutagenesis) and epigenetic changes in histones 3 and 4 (H3 and H4). This may further cause molecular events triggering different pathological conditions and eventually cancer. In both cytoplasm and nucleus, Asc provided increases in 3,5‐DMAP‐reduced glutathione levels and cellular redox ratio and decreases in the lipid peroxidation and protein oxidation. Asc was also found to be protective against the genotoxic and epigenetic effects initiated by 3,5‐DMAP. In addition, Asc supplied protection against the cell cycle (G1 phase) arrest induced by this particular alkylaniline metabolite.
      PubDate: 2014-09-01T06:51:00.294209-05:
      DOI: 10.1002/jat.3046
       
  • In utero and early childhood exposure to arsenic decreases lung function
           in children
    • Authors: Rogelio Recio‐Vega; Tania Gonzalez‐Cortes, Edgar Olivas‐Calderon, R. Clark Lantz, A. Jay Gandolfi, Cesar Gonzalez‐De Alba
      Abstract: The lung is a target organ for adverse health outcomes following exposure to As. Several studies have reported a high prevalence of respiratory symptoms and diseases in subjects highly exposed to As through drinking water; however, most studies to date has been performed in exposed adults, with little information on respiratory effects in children. The objective of the study was to evaluate the association between urinary levels of As and its metabolites with lung function in children exposed in utero and in early childhood to high As levels through drinking water. A total of 358 healthy children were included in our study. Individual exposure was assessed based on urinary concentration of inorganic As. Lung function was assessed by spirometry. Participants were exposed since pregnancy until early childhood to an average water As concentration of 152.13 µg l–1. The mean urinary As level registered in the studied subjects was 141.2 µg l–1 and only 16.7% had a urinary concentration below the national concern level. Forced vital capacity was significantly decreased in the studied population and it was negatively associated with the percentage of inorganic As. More than 57% of the subjects had a restrictive spirometric pattern. The urinary As level was higher in those children with restrictive lung patterns when compared with the levels registered in subjects with normal spirometric patterns. Exposure to As through drinking water during in utero and early life was associated with a decrease in forced vital capacity and with a restrictive spirometric pattern in the children evaluated. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-15T08:01:31.55848-05:0
      DOI: 10.1002/jat.3023
       
  • Development of haemostatic decontaminants for the treatment of wounds
           contaminated with chemical warfare agents. 1: Evaluation of in vitro
           clotting efficacy in the presence of certain contaminants
    • Authors: Charlotte A. Hall; Helen L. Lydon, Christopher H. Dalton, J. K. Chipman, John S. Graham, Robert P. Chilcott
      Abstract: The treatment of penetrating, haemorrhaging injuries sustained within a hazardous environment may be complicated by contamination with toxic chemicals. There are currently no specific medical countermeasures for such injuries. Haemostats with an absorbent mechanism of action have the potential to simultaneously stop bleeding and decontaminate wounds. However, a primary requirement of a ‘haemostatic decontaminant’ is the retention of clotting function in the presence of chemical contaminants. Thus, the aim of this study was to investigate the haemostatic efficacy of seven commercially available haemostats in the presence of toxic chemicals (soman, VX, sulphur mustard, petrol, aviation fuel and motor oil). Clot viscosity was assessed ex vivo using thrombelastography following treatment of pig blood with: (i) toxic chemical; (ii) haemostat; or (iii) haemostat in combination with toxic chemical. Several contaminants (VX, petrol and GD) were found to be pro‐haemostatic and none had an adverse effect on the rate with which the test products attained haemostasis. However, the total clot strength for blood treated with certain haemostats in the presence of sulphur mustard, soman and petrol was significantly decreased. Three test products failed to demonstrate haemostatic function in this ex vivo (thrombelastography) model; this was tentatively ascribed to the products achieving haemostasis through a tamponade mechanism of action, which can only be replicated using in vivo models. Overall, this study has identified a number of commercial products that may have potential as haemostatic decontaminants and warrant further investigation to establish their decontaminant efficacy. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-15T07:46:27.370339-05:
      DOI: 10.1002/jat.3019
       
  • Systemic drugs inducing non‐immediate cutaneous adverse reactions
           and contact sensitizers evoke similar responses in THP‐1 cells
    • Authors: Margarida Gonçalo; João Martins, Ana Silva, Bruno Neves, Américo Figueiredo, Teresa Cruz, Celeste Lopes
      Abstract: Contact sensitizers induce phenotypic and functional changes in dendritic cells (DC) that enhance their antigen‐presenting capacity and, ultimately, modulate the T cell response. To evaluate if there is a similar effect of drugs causing T‐cell‐mediated cutaneous adverse drug reactions (CADR), we studied the in vitro effect of drugs on THP‐1 cells, a cell line widely used to evaluate the early molecular and cellular events triggered by contact sensitizers. The effect of allopurinol, oxypurinol, ampicillin, amoxicillin, carbamazepine and sodium valproate, at EC30 concentrations, was evaluated on p38 MAPK activation, by Western Blot, and on the expression of genes coding for DC maturation markers, pro‐inflammatory cytokine/chemokines and hemeoxygenase 1 (HMOX1), by real‐time RT‐PCR. Results were compared with lipopolysaccharide (LPS), a DC maturation stimulus, and the strong contact sensitizer, 1‐fluoro‐2,4‐dinitrobenzene (DNFB). All drugs studied significantly upregulated HMOX1 gene transcription and all, except the anticonvulsants, also upregulated IL8. Allopurinol and oxypurinol showed the most intense effect, in a magnitude similar to DNFB and superior to betalactams. Transcription of CD40, IL12B and CXCL10 genes by drugs was more irregular. Moreover, like DNFB, all drugs activated p38 MAPK, although significantly only for oxypurinol. Like contact sensitizers, drugs that cause non‐immediate CADR activate THP‐1 cells in vitro, using different signalling pathways and affecting gene transcription with an intensity that may reflect the frequency and severity of the CADR they cause. Direct activation of antigen‐presenting DC by systemic drugs may be an important early step in the pathophysiology of non‐immediate CADR. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-04T09:46:53.569007-05:
      DOI: 10.1002/jat.3033
       
  • Analysis of drugs of abuse in human plasma by dispersive
           liquid–liquid microextraction and high‐performance liquid
           chromatography
    • Authors: P. Fernández; M. Regenjo, A. M. Bermejo, A. M. Fernández, R. A. Lorenzo, A. M. Carro
      Abstract: Opioids and cocaine are widely used at present, both for recreational purposes and as drugs of abuse. This raises the need to develop new analytical methods specifically designed for the simultaneous detection of several drugs of abuse in biological samples. In this work, dispersive liquid–liquid microextraction (DLLME) was assessed as a new sample treatment for the simultaneous extraction of morphine (MOR), 6‐acetylmorphine (6AM), cocaine (COC), benzoylecgonine (BZE) and methadone (MET) from human plasma. Preliminary assays were done before developing an experimental design based on a Uniform Network Doehlert which allowed the optimum extraction conditions to be identified, namely: a volume of extractant solvent (chloroform) and dispersant solvent (acetonitrile) of 220 µl and 3.2 ml, respectively; 0.2 g of NaCl as a salting‐out additive; pH 10.6 and ultrasound stirring for 3.5 min. The resulting extracts were analyzed by high‐performance liquid chromatography with photodiode array detection (HPLC‐PDA), using an XBridge® RP18 column (250 × 4.6 mm i.d., 5 µm particle size). Calibration graphs were linear over the concentration range 0.1–10 µg ml–1, and detection limits ranged from 13.9 to 28.5 ng ml–1. Precision calculated at three different concentration levels in plasma was included in the range 0.1–6.8% RSD. Recoveries of the five drugs were all higher than 84% on average. Finally the proposed method was successfully applied to 22 plasma samples from heroin, cocaine and/or methadone users, and the most frequently detected drug was benzoylecgonine, followed by methadone, cocaine and morphine. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-04T09:42:27.742954-05:
      DOI: 10.1002/jat.3035
       
  • The relationship between chemical‐induced kidney weight increases
           and kidney histopathology in rats
    • Authors: Evisabel A. Craig; Zhongyu Yan, Q. Jay Zhao
      Abstract: The kidney is a major site of chemical excretion, which results in its propensity to exhibit chemically‐induced toxicological effects at a higher rate than most other organs. Although the kidneys are often weighed in animal toxicity studies, the manner in which these kidney weight measurements are interpreted and the value of this information in predicting renal damage remains controversial. In this study we sought to determine whether a relationship exists between chemically‐induced kidney weight changes and renal histopathological alterations. We also examined the relative utility of absolute and relative (kidney‐to‐body weight ratio) kidney weight in the prediction of renal toxicity. For this, data extracted from oral chemical exposure studies in rats performed by the National Toxicology Program were qualitatively and quantitatively evaluated. Our analysis showed a statistically significant correlation between absolute, but not relative, kidney weight and renal histopathology in chemically‐treated rats. This positive correlation between absolute kidney weight and histopathology was observed even with compounds that statistically decreased terminal body weight. Also, changes in absolute kidney weight, which occurred at subchronic exposures, were able to predict the presence or absence of kidney histopathology at both subchronic and chronic exposures. Furthermore, most increases in absolute kidney weight reaching statistical significance (irrespective of the magnitude of change) were found to be relevant for the prediction of histopathological changes. Hence, our findings demonstrate that the evaluation of absolute kidney weight is a useful method for identifying potential renal toxicants. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-04T09:42:22.00032-05:0
      DOI: 10.1002/jat.3036
       
  • Protective role of L‐ascorbic acid, N‐acetylcysteine and
           apocynin on neomycin‐induced hair cell loss in Zebrafish
    • Authors: Chia‐Yen Wu; Han‐Jung Lee, Chi‐Fang Liu, Mallikarjuna Korivi, Hwei‐Hsien Chen, Ming‐Huan Chan
      Abstract: Hair cells are highly sensitive to environmental insults and other therapeutic drugs. The adverse effects of drugs such as aminoglycosides can cause hair cell death and lead to hearing loss and imbalance. The objective of the present study was to evaluate the protective activity of L‐ascorbic acid, N‐acetylcysteine (NAC) and apocynin on neomycin‐induced hair cell damage in zebrafish (Danio rerio) larvae at 5 days post fertilization (dpf). Results showed that the loss of hair cells within the neuromasts of the lateral lines after neomycin exposure was evidenced by a significantly lower number of neuromasts labeled with fluorescent dye FM1‐43FX observed under a microscope. Co‐administration with L‐ascorbic acid, NAC and apocynin protected neomycin‐induced hair cell loss within the neuromasts. Moreover, these three compounds reduced the production of reactive oxygen species (ROS) in neuromasts exposed to neomycin, indicating that their antioxidant action is involved. In contrast, the neuromasts were labeled with specific fluorescent dye Texas‐red conjugated with neomycin to detect neomycin uptake. Interestingly, the uptake of neomycin into hair cells was not influenced by these three antioxidant compounds. These data imply that prevention of hair cell damage against neomycin by L‐ascorbic acid, NAC and apocynin might be associated with inhibition of excessive ROS production, but not related to modulating neomycin uptake. Our findings conclude that L‐ascorbic acid, NAC and apocynin could be used as therapeutic drugs to protect aminoglycoside‐induced listening impairment after further confirmatory studies. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-04T09:42:16.707002-05:
      DOI: 10.1002/jat.3043
       
  • Plasma miR‐208 as a useful biomarker for drug‐induced
           cardiotoxicity in rats
    • Authors: Yoko Nishimura; Chiaki Kondo, Yuji Morikawa, Yutaka Tonomura, Mikinori Torii, Jyoji Yamate, Takeki Uehara
      Abstract: Cardiotoxicity is one of the major safety concerns in drug development. Therefore, detecting and monitoring cardiotoxicity throughout preclinical and clinical studies is important for pharmaceutical companies. The present study was conducted in order to explore a plasma miRNA biomarker for cardiotoxicity in rats. As organ specificity is an important factor for a biomarker, we analyzed the miRNA microarray dataset in 55 organs/tissues in normal male rats. Based on this analysis, 5 miRNAs consisting of miR‐208 (heart‐specific), miR‐1, miR‐133a, miR‐133b (heart and skeletal muscle‐specific) and miR‐206 (skeletal muscle‐specific) were selected. Next, we evaluated the usefulness of those 5 miRNAs as circulating biomarkers in rats administered with single‐dose isoproterenol or doxorubicin. Plasma miR‐208 was consistently increased through 24 h after dosing in rats administered with isoproterenol, whereas plasma concentrations of cardiac troponin (cTn) showed transient elevation. In contrast, the plasma levels of miR‐1, miR‐133a, miR‐133a and miR‐206 were elevated after treatment with doxorubicin, probably as a result of skeletal muscle toxicity. Additionally, the plasma miR‐208 level was elevated even after repeat‐dose administration (once daily for 7 days) of isoproterenol under which the pathological condition proceeded to the sub‐chronic phase such as fibrosis. Thus, our data suggest that miR‐208 is a promising plasma biomarker for cardiotoxicity in rats. Monitoring of plasma miR‐208 levels in rats may lead to more accurate evaluation of cardiotoxicity in preclinical studies. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-08-04T09:03:05.796088-05:
      DOI: 10.1002/jat.3044
       
  • Vascular endothelial growth factor mRNA levels as a biomarker for
           short‐term N‐butyl‐N‐(4‐hydroxybutyl)
           nitrosamine‐induced rat bladder carcinogenesis bioassay
    • Authors: Shin Wakui; Tomoko Mutou, Hiroyuki Takahashi, Masahiro Ikegami, Hideki Wanibuchi, Shoji Fukushima
      Abstract: Generically, carcinogenic effects of chemicals in bladder carcinogenesis are judged by induction of papillary or nodular (PN) hyperplasia in rats given N‐butyl‐N‐(4‐hydroxybutyl) nitrosamine (BBN) for 4 weeks and the test chemical for 22–28 weeks. However, upregulation of vascular endothelial growth factor (VEGF) begins early in rat BBN bladder carcinogenesis. To establish a short‐term rat bladder carcinogenic bioassay, we analyzed the correlations between VEGF, VEGF mRNA and bladder lesions inductions at 10 and 26 weeks after BBN treatment. Six‐week‐old male Wistar (slc) rats were given 0.05% BBN for 4, 10 or 26 weeks. To avoid individual rat bias, the bladders were investigated by partial cystectomy at 10 weeks and total cystectomy at 26 weeks. After induction, PN hyperplasia and carcinoma in rats increased with the length of BBN treatment and immunohistochemical VEGF expression also increased following carcinogenesis, but the immunoreactivity of individual lesions was quite variable. Moreover, induction of PN hyperplasia at 10 weeks’ BBN treatment was not significantly correlated with that at 26 weeks' treatment; thus, it was not possible to predict the carcinogenic effect due to the induction of PN hyperplasia at 26 weeks' BBN treatment by that at 10 weeks' treatment. However, VEGF mRNA levels of rat bladders at 10 weeks' BBN treatment revealed a strong significant correlation with the incidence of bladder lesions at 26 weeks' treatment. Here, we suggest that quantitative VEGF mRNA levels are a good biomarker for a short‐term BBN‐induced bioassay for rat bladder carcinogenesis. Copyright © 2014 John Wiley & Sons, Ltd.
      PubDate: 2014-05-28T09:25:42.146279-05:
      DOI: 10.1002/jat.3021
       
  • Quantitative evaluation of the pulmonary microdistribution of TiO2
           nanoparticles using X‐ray fluorescence microscopy after
           intratracheal administration with a microsprayer in rats
    • Abstract: The unevenness of pulmonary nanoparticle (NP) distribution, which hinders the establishment of an absolute dose–response relationship, has been described as one of the limitations of intratracheal administration techniques for toxicological assessment of inhaled NPs. Quantification of the NP microdistribution would facilitate the establishment of a concentration–response relationship in localized regions of the lung; however, such quantitative methods have not been reported. Here, we established a quantitative method for evaluating pulmonary TiO2 NP microdistribution in rats using X‐ray fluorescence microscopy. Ti intensity in lung sections from rats intratracheally administered 10 mg kg–1 TiO2 NPs with a microsprayer was measured using X‐ray fluorescence with a 100 µm beam size. Ti reference samples were prepared by dropping different concentrations of Ti solutions on glass slide or lung sections of untreated rat. Ti intensity increased linearly with Ti content in the reference samples on both substrates. The detection limit of TiO2 was estimated to be 6.3 ng mm–2. The reproducibility was confirmed for measurements done in the short‐ (2 weeks) and long‐term (6 months). The quantitative results of TiO2 NP microdistribution suggested that more TiO2 NPs were distributed in the right caudal and accessory lobes, which are located downstream of the administration direction of the NP suspension, and the lower portion of each lobe. The detection rates of TiO2 NPs were 16.6–25.0%, 5.19–15.6%, 28.6–39.2%, 21.4–38.7% and 10.6–23.2% for lung sections from the right cranial, middle, caudal, accessory and left lobes, respectively. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Effects of homocysteine on mesenchymal cell proliferation and
           differentiation during chondrogenesis on limb development
    • Abstract: High levels of homocysteine (Hcy) are related to an increased risk of the occurrence of congenital anomalies, including limb defects. However, few evaluations about how toxic levels of Hcy affect limb development have been reported. We investigated whether Hcy can affect the cell cycle proteins and proteins involved in mesenchymal cell differentiation during limb development, in a chicken embryo model. Embryos were treated with 20 µmol d‐l Hcy/50 µl saline at embryonic day 2 and analyzed at embryonic day 6. Untreated control embryos received exclusively 50 µl saline solution. To identify cells in proliferation and cell cycle proteins, as well as Pax1/9 and Sox9 proteins, we performed immunolocalization and flow cytometry analyses using the antibodies anti‐phosphohistone H3, anti‐p53, anti‐p21, anti‐proliferating cell nuclear antigen, anti‐Pax1, anti‐Pax9 and anti‐Sox9. No significant differences in cell proliferation were observed between Hcy‐treated and untreated embryos. We observed a decrease of the proliferating cell nuclear antigen and p21 proteins, both involved in the G1 phase of cell cycle progression. On the other hand, in mesenchymal cells of the limbs, Hcy induces an increase of p53 protein, which can be activated by DNA damage. In cell differentiation, Hcy induced an increase mainly of Pax9 and Sox9 proteins. Our data indicate that the treatment with Hcy changes the mesenchymal cell dynamics during limb development, but does not change the morphology of the cartilage molds. These findings provide information to understand better the cellular basis of the toxicity of Hcy on chondrogenesis during limb development. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Bisphenol A exposure induces metabolic disorders and enhances
           atherosclerosis in hyperlipidemic rabbits
    • Abstract: Bisphenol A (BPA) is an artificial environmental endocrine disrupter. Excess exposure to BPA may induce many disorders in the metabolism and cardiovascular system. However, the underlying toxicological mechanisms remain largely unknown. In this study, we administered genetically hyperlipidemic Watanabe heritable hyperlipidemic (WHHL‐MI) rabbits (male, 14 week old), which have more common features with humans than the mouse and rat especially in the metabolism and cardiovascular system, with BPA at 40 mg kg–1 day–1 for 8 weeks by gavage and compared their plasma lipids, glucose and insulin response with those of the vehicle group. All of the rabbits were sacrificed, and their pancreas, liver, adipose tissue, heart and aorta were analyzed using histological and morphometric methods. Furthermore, we treated human hepatoma HepG2 cells and human umbilical cord vein endothelial cells (HUVECs), with different doses of BPA based on the serum BPA levels in the WHHL rabbits for 6 h to investigate the possible molecular mechanisms. Our results showed that BPA‐treated rabbits showed insulin resistance, prominent adipose accumulation and hepatic steatosis. Additionally, BPA exposure also caused myocardial injury and enhanced the development of atherosclerosis in the aortic arch with increased macrophage number (86%) and advanced lesion areas (69%). Increased expression of inflammatory genes found in the liver of BPA‐treated rabbits along with the up‐regulation of ER stress, lipid and glucose homeostasis and inflammatory genes in the cultured HepG2 cells and HUVECs suggest that BPA may induce metabolic disorders and enhance atherosclerosis through regulating above molecular pathways in the liver and endothelium. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Memorial address to Dr Tohru Inoue
    •  
  • Toxicity of cobalt–chromium nanoparticles released from a
           resurfacing hip implant and cobalt ions on primary human lymphocytes in
           vitro
    • Abstract: Adverse tissue responses to prostheses wear particles and released ions are important contributors to hip implant failure. In implant‐related adverse reactions T‐lymphocytes play a prominent role in sustaining the chronic inflammatory response. To further understand the involvement of lymphocytes in metal‐on‐metal (MoM) implant failure, primary human lymphocytes were isolated and treated with cobalt–chromium (Co‐Cr) wear debris and Co ions, individually, and in combination, for 24, 48 and 120 h. There was a significant increase in cell number where debris was present, as measured by the Neutral Red assay. Interleukin‐6 (IL‐6), interferon‐γ (IFN‐γ) and tumour necrosis factor‐α (TNF‐α) secretion levels significantly decreased in the presence of metal particles, as measured by ELISA. Interleukin‐2 (IL‐2) secretion levels were significantly decreased by both debris and Co ions. Flow cytometry analysis showed that the metal nanoparticles induced a significant increase in apoptosis after 48‐h exposure. This investigation showed that prolonged exposure (120 h) to metal debris induces lymphocyte proliferation, suggesting that activation of resting lymphocytes may have occurred. Although cytokine production was affected mainly by metal debris, cobalt toxicity may also modulate IL‐2 secretion, and even Co ion concentrations below the MHRA guideline levels (7 ppb) may contribute to the impairment of immune regulation in vivo in patients with MoM implants. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Cytotoxicity of luteolin in primary rat hepatocytes: the role of
           CYP3A‐mediated ortho‐benzoquinone metabolite formation and
           glutathione depletion
    • Abstract: Luteolin (LUT), an active ingredient in traditional Chinese medicines and an integral part of the human diet, has shown promising pharmacological activities with a great potential for clinical use. The purpose of this study was to evaluate the role of cytochrome P450 (CYP450)‐mediated reactive ortho‐benzoquinone metabolites formation and glutathione (GSH) depletion in LUT‐induced cytotoxicity in primary rat hepatocytes. A reactive ortho‐benzoquinone metabolite was identified by liquid chromatography coupled with tandem mass spectrometry (LC‐MS/MS) in rat liver microsomes (RLMs) and rat hepatocytes. Using a specific chemical inhibitor method, the CYP3A subfamily was found to be responsible for the reactive metabolite formation in RLMs. Induction of CYP3A by dexamethasone enhanced LUT‐induced cytotoxicity, whereas inhibition of CYP3A by ketoconazole (Keto) decreased the cytotoxicity. The cytotoxicity and cell apoptosis induced by LUT were related to the amount of reactive metabolite formation. Furthermore, Keto inhibited the LUT‐induced GSH exhaustion. The cytotoxicity was significantly enhanced by pretreatment with L‐buthionine sulfoximine to deplete the intracellular GSH. A time course experiment showed that GSH depletion by LUT was not via oxidation of GSH and occurred prior to the increase in 2', 7'‐dichlorofluorescein in hepatocytes. Collectively, these data suggest that CYP3A‐mediated reactive metabolite formation plays a critical role in LUT‐induced hepatotoxicity, and the direct GSH depletion is an initiating event in LUT‐mediated cytotoxicity in primary rat hepatocytes. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Genomic and gene expression responses to genotoxic stress in PAC2
           zebrafish embryonic cell line
    • Abstract: PAC2 cell line is, along most of the developed zebrafish cell lines, poorly characterized concerning its response to genotoxicants. To define the PAC2 cell line response to different forms of genotoxic stress, we exposed the cells to model genotoxic agents (benzo[a]pyrene, B[a]P, and ethyl methanesulfonate) and subsequently monitored DNA damage and alterations by using the battery of tests, including the Comet assay, quantitative random‐amplified polymorphic DNA and amplified fragment length polymorphism. The expression of several DNA repair (xpc, xpd, hr23b, rad51, msh2) and oxidative stress response (sod (Cu/Zn)) genes was monitored as well. To obtain an indication of the PAC2 cell line metabolizing capacity, the expression of genes belonging to cyp1, cyp2 and cyp3 families was assessed upon exposure to B[a]P. Genotoxic responses were observed in all the used methods, and quantitative random‐amplified polymorphic DNA and amplified fragment length polymorphism proved to be more sensitive by revealing DNA alterations even when the Comet assay indicated lack of significant damage. The PAC2 cell line demonstrated basal and B[a]P‐induced expression of several cyp genes, suggesting its ability to metabolize indirect acting xenobiotics to a certain point. Based on these results, PAC2 cells seem to be sensitive zebrafish in vitro model in the genotoxicity assessment of the direct acting genotoxicant; however, they are less sensitive toward the indirect acting genotoxicant due to their limited metabolizing properties. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Effects of lithium on growth, maturation, reproduction and gene expression
           in the nematode Caenorhabditis elegans
    • Abstract: Lithium (Li) has been widely used to treat bipolar disorder, and industrial use of Li has been increasing; thus, environmental pollution and ecological impacts of Li have become a concern. This study was conducted to clarify the potential biological effects of LiCl and Li2CO3 on a nematode, Caenorhabditis elegans as a model system for evaluating soil contaminated with Li. Exposure of C. elegans to LiCl and Li2CO3 decreased growth/maturation and reproduction. The lowest observed effect concentrations for growth, maturation and reproduction were 1250, 313 and 10 000 µm, respectively, for LiCl and 750, 750 and 3000 µm, respectively, for Li2CO3. We also investigated the physiological function of LiCl and LiCO3 in C. elegans using DNA microarray analysis as an eco‐toxicogenomic approach. Among approximately 300 unique genes, including metabolic genes, the exposure to 78 µm LiCl downregulated the expression of 36 cytochrome P450, 16 ABC transporter, 10 glutathione S‐transferase, 16 lipid metabolism and two vitellogenin genes. On the other hand, exposure to 375 µm Li2CO3 downregulated the expression of 11 cytochrome P450, 13 ABC transporter, 13 lipid metabolism and one vitellogenin genes. No gene was upregulated by LiCl or Li2CO3. These results suggest that LiCl and Li2CO3 potentially affect the biological and physiological function in C. elegans associated with alteration of the gene expression such as metabolic genes. Our data also provide experimental support for the utility of toxicogenomics by integrating gene expression profiling into a toxicological study of an environmentally important organism such as C. elegans. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Endocrine‐disrupting potentials of equine estrogens equilin,
           equilenin, and their metabolites, in the medaka Oryzias latipes: in silico
           and DNA microarray studies
    • Abstract: Although several previous studies have demonstrated the presence of equine estrogens in the aquatic environment, limited data are currently available on the endocrine‐disrupting potentials in fish and the risks they pose to aquatic organisms. To investigate the interactions of major equine estrogens equilin (Eq) and equilenin (Eqn), as well as their metabolites 17α‐dihydroequilin, 17β‐dihydroequilin, 17α‐dihydroequilenin and 17β‐dihydroequilenin, with the estrogen receptor α (ERα) of medaka (Oryzias latipes), a three‐dimensional model of the ligand‐binding domain (LBD) of ERα was built in silico, and docking simulations were performed. The docking simulation analysis indicated that the interaction of 17β‐dihydroequilenin with the ERα LBD is the most potent, followed by those of 17α‐dihydroequilin and 17β‐dihydroequilin, whereas those of Eq and Eqn were least potent. We further analyzed gene expression profiles in the livers of male medaka exposed to Eq and Eqn. A DNA microarray representing 6000 genes revealed that 24‐h exposure to Eq and Eqn (100 ng/L) upregulated the expression of 6 and 34 genes in the livers of males, respectively. Genes upregulated by Eq included the estrogenic biomarker genes vitellogenins and choriogenins, suggesting the estrogenic potential of Eq. In contrast, Eqn exposure upregulated several cancer‐related genes, such as mediator complex subunit 16 and RAS oncogene family members, suggesting a carcinogenic potential for Eqn. These results suggest that equine estrogens may have not only endocrine‐disrupting potentials via the ERα signaling pathway but also carcinogenic potency in male medaka. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Cobalt oxide nanoparticles induced oxidative stress linked to activation
           of TNF‐α/caspase‐8/p38‐MAPK signaling in human
           leukemia cells
    • Abstract: The purpose of this study was to determine the intracellular signaling transduction pathways involved in oxidative stress induced by nanoparticles in cancer cells. Activation of reactive oxygen species (ROS) has some therapeutic benefits in arresting the growth of cancer cells. Cobalt oxide nanoparticles (CoO NPs) are an interesting compound for oxidative cancer therapy. Our results showed that CoO NPs elicited a significant (P
       
  • Quantitative toxicoproteomic analysis of zebrafish embryos exposed to a
           retinoid X receptor antagonist UVI3003
    • Abstract: Retinoid X receptor (RXR) antagonists, including some environmental endocrine disruptors, have a teratogenic effect on vertebrate embryos. To investigate the toxicological mechanism on the protein expression level, a quantitative proteomic study was conducted to analyze the proteome alterations of zebrafish (Danio rerio) embryos exposed to gradient concentrations of a representative RXR antagonist UVI3003. Using isobaric Tags for Relative and Absolute Quantitation (iTRAQ) labeling coupled nano high‐performance liquid chromatography‐tandem mass spectrometry (nano HPLC‐MS/MS), in total 6592 proteins were identified, among which 195 proteins were found to be differentially expressed by more than a two‐fold change in exposed groups compared with the control. Gene ontology analysis showed that these differential proteins were mostly involved in anatomical structure development, biosynthetic process, ion binding and oxidoreductase activity. Moreover, the biological pathways of translation, lipoprotein metabolism, cell survival and gluconeogenesis were intensively inhibited after exposure. Some significantly downregulated proteins such as apolipoprotein A‐I and vitellogenin and upregulated proteins such as calcium activated nucleotidase 1b, glutathione S‐transferase and glucose 6‐dehydrogenases showed a strong dose‐dependent response. The results provided new insight into the molecular details of RXR antagonist‐induced teratogenicity and added novel information of pathways and potential biomarkers for evaluation of RXR interfering activity. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • The toxicity and distribution of iron oxide–zinc oxide
           core‐shell nanoparticles in C57BL/6 mice after repeated subcutaneous
           administration
    • Abstract: Therapeutic cancer vaccines promote immune responses by delivering tumour‐specific antigens. Recently, we developed iron oxide (Fe3O4)–zinc oxide (ZnO) core‐shell nanoparticles (CSNPs) as carriers for antigen delivery into dendritic cells (DCs), and the CSNPs were injected subcutaneously into C57BL/6 mice to examine the systemic toxicity, tissue distribution and excretion of the CSNPs. The doses injected were 0, 4, 20 and 200 mg kg–1 weekly for 4 weeks. No significant changes were observed after the CSNPs administration with respect to mortality, clinical observations, body weight, food intake, water consumption, urinalysis, haematology, serum biochemistry,and organ weights. A dose‐dependent increase in granulomatous inflammation was observed at the injection site of the CSNP‐treated animals, but no other histopathological lesions in other organs could be attributed to the CSNPs. The Zn concentration, which is an indicator for CSNPs, was not significantly higher in the sampled tissues, urine, or faeces after the CSNP injection. In contrast, the Zn concentration at the subcutaneous skin of the site injected with the CSNPs increased in a dose‐dependent manner, along with a macroscopic deposition of the CSNPs. The CSNP residue at the injection site resulted in a foreign body response with the appearance of macrophage infiltration, but otherwise did not show any systemic distribution or toxicity at up to 200 mg kg–1 during this study. In conclusion, CSNPs could be used as good antigen carriers for DC‐based immunotherapy, although further study is needed to completely clear the residue of the CSNPs at the injection site. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Enhanced QSAR models for drug‐triggered inhibition of the main
           cardiac ion currents
    • Abstract: The currently changing cardiac safety testing paradigm suggests, among other things, a shift towards using in silico models of cellular electrophysiology and assessment of a concomitant block of multiple ion channels. In this study, a set of four enhanced QSAR models have been developed: for the rapid delayed rectifying potassium current (IKr), slow delayed rectifying potassium current (IKs), peak sodium current (INa) and late calcium current (ICaL), predicting ion currents changes for the specific in vitro experiment from the 2D structure of the compounds. The models are a combination of both in vitro study parameters and physico‐chemical descriptors, which is a novel approach in drug–ion channels interactions modeling. Their predictive power assessed in the enhanced, more demanding than standard procedure, 10‐fold cross validation was reasonably high. Rough comparison with published pure in silico hERG interaction models shows that the quality of the model predictions does not differ from other models available in the public domain, however, it takes its advantage in accounting for inter‐experimental settings variability. Developed models are implemented in the Cardiac Safety Simulator, a commercially available platform enabling the in vitro–in vivo extrapolation of the drugs proarrhythmic effect and ECG simulation. A more comprehensive assessment of the effects of the compounds on ion channels allows for making more informed decisions regarding the risk – and thus avoidance – of exclusion of potentially safe and effective drugs. Copyright © 2015 John Wiley & Sons, Ltd.
       
  • Dimethylarsinic acid (DMAV) changed the expressions of proliferative
           related factors and secretion of inflammatory cytokines in rat bladder
    • Abstract: Dimethylarsinic acid (DMAV), the major urinary metabolite of inorganic arsenic, is a urinary bladder carcinogen and bladder tumor promoter in adult rats. Increased urothelial cellular proliferation has been considered as an earlier phenotype in DMAV‐induced bladder carcinogenesis. The present study examined the ultrastructural changes of bladder epithelial cells and expressions of proliferation factors, as well as the secretion of inflammatory cytokines in rats exposed to DMAV for 10 weeks by transmission electron microscopy (TEM), qRT‐PCR, immunohistochemical staining and ELISA methods. The results showed that DMAV administered in the drinking water produced urothelial cytotoxicity and ultrastructural changes in rats. PCNA, cyclin D1 and COX‐2 mRNA expressions and immunoreactivities were elevated in bladder urothelium. In addition, 200 ppm DMAV treatment increased the transforming growth factor‐beta 1 (TGF‐β1) secretion and decreased tumor necrosis factor‐alpha (TNF)‐α level in the urine of rats. These data suggest that chronic inflammation, bladder epithelium lesions and proliferation might be the basic process of the chronic toxicity effects in DMAV‐treated rats. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • Usefulness of urinary kidney injury molecule‐1 (Kim‐1) as a
           biomarker for cisplatin‐induced sub‐chronic kidney injury
    • Abstract: We explored biomarkers suitable for monitoring sub‐chronic kidney injury using the three rat models of cisplatin (CDDP)‐induced kidney injury, which were designed to extend the current knowledge beyond the sub‐acute exposure period. In the pilot study, a single intravenous administration of 1.5 mg kg–1 CDDP to rats was confirmed to result in no histopathological changes. Subsequently, CDDP was intravenously administered to rats at a dose of 1.5 mg kg–1 for 4 days at 24‐h intervals (Experimental model 1) and for up to 10 weeks at weekly intervals (Experimental models 2 and 3), and the changes in blood and urine components, such as recently recommended urinary biomarkers (Kim‐1, clusterin and so on) and traditional blood biomarkers (blood urea nitrogen and serum creatinine), were examined together with the histopathological changes in renal tissues during the development of the kidney injury in each model. In these experimental models, a significant increase in urinary Kim‐1 was observed prior to the histopathological changes in renal tissues, and these changes were retained after the adverse histopathological changes. Significant changes in all of the other urinary biomarkers examined occurred along with the histopathological changes. In addition, the increase in urinary Kim‐1 after weekly treatment with CDDP for 4 weeks was reduced in a time‐dependent manner after cessation of the drug. The present findings indicate that urinary Kim‐1 is the most useful biomarker for CDDP‐induced rat sub‐chronic kidney injury among the biomarkers examined. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • Evaluation of developmental toxicity using undifferentiated human
           embryonic stem cells
    • Abstract: An embryonic stem cell test (EST) has been developed to evaluate the embryotoxic potential of chemicals with an in vitro system. In the present study, novel methods to screen toxic chemicals during the developmental process were evaluated using undifferentiated human embryonic stem (hES) cells. By using surface marker antigens (SSEA‐4, TRA‐1‐60 and TRA‐1‐81), we confirmed undifferentiated conditions of the used hES cells by immunocytochemistry. We assessed the developmental toxicity of embryotoxic chemicals, 5‐fluorouracil, indomethacin and non‐embryotoxic penicillin G in different concentrations for up to 7 days. While expressions of the surface markers were not significantly affected, the embryotoxic chemicals influenced their response to pluripotent ES cell markers, such as OCT‐4, NANOG, endothelin receptor type B (EDNRB), secreted frizzled related protein 2 (SFRP2), teratocarcinoma‐derived growth factor 1 (TDGF1), and phosphatase and tensin homolog (PTEN). Most of the pluripotent ES cell markers were down‐regulated in a dose‐dependent manner after treatment with embryotoxic chemicals. After treatment with 5‐fluorouracil, indomethacin and penicillin G, we observed a remarkable convergence in the degree of up‐regulation of development, cell cycle and apoptosis‐related genes by gene expression profiles using an Affymetrix GeneChips. Taken together, these results suggest that embryotoxic chemicals have cytotoxic effects, and modulate the expression of ES cell markers as well as development‐, cell cycle‐ and apoptosis‐related genes that have pivotal roles in undifferentiated hES cells. Therefore, we suggest that hES cells may be useful for testing the toxic effects of chemicals that could impact the embryonic developmental stage. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • Usefulness of optical coherence tomography to detect central serous
           chorioretinopathy in monkeys
    • Abstract: Many systemic drugs can induce ocular toxicity and several ocular side‐effects have been identified in clinical studies. However, it is difficult to detect ocular toxicity in preclinical studies because of the lack of appropriate evaluation methods. Optical coherence tomography (OCT) is useful because it can provide real‐time images throughout a study period, whereas histopathology only provides images of sacrificed animals. Using OCT alongside histopathology, attempts were made to find effective approaches for screening of drug‐induced ocular toxicity in monkeys. Such approaches could be used in preclinical studies prior to human trials. Six male cynomolgus monkeys (Macaca fascicularis Raffles) were orally administered one of six candidate MAPK/ERK kinase (MEK) inhibitors. Central serous chorioretinopathy, a known side‐effect of such inhibitors, was identified in four monkeys by OCT. Artifacts generated during tissue processing meant that histopathology could not detect edematous changes. Thus, OCT is a useful tool to detect ocular toxicity which cannot be detected by histopathology in preclinical studies. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • All‐cause mortality increased by environmental cadmium exposure in
           the Japanese general population in cadmium non‐polluted areas
    • Abstract: The aim of the present study was to evaluate the effect of environmental cadmium (Cd) exposure indicated by urinary Cd on all‐cause mortality in the Japanese general population. A 19‐year cohort study was conducted in 1067 men and 1590 women aged 50 years or older who lived in three cadmium non‐polluted areas in Japan. The subjects were divided into four quartiles based on creatinine adjusted U‐Cd (µg g−1 cre). The hazard ratio (HR) and 95% confidence interval (CI) for continuous U‐Cd or the quartiles of U‐Cd were estimated for all‐cause mortality using a proportional hazards regression.The all‐cause mortality rates per 1000 person years were 31.2 and 15.1 in men and women, respectively. Continuous U‐Cd (+1 µg g−1 cre) was significantly related to the all‐cause mortality in men (HR 1.05, 95% CI: 1.02–1.09) and women (HR 1.04, 95% CI: 1.01–1.07). Furthermore in men, the third (1.96–3.22 µg g−1 cre) and fourth quartile (≥3.23 µg g−1 cre) of U‐Cd showed a significant, positive HR (third: HR 1.35, 95% CI: 1.03–1.77, fourth: HR 1.64, 95% CI: 1.26–2.14) for all‐cause mortality compared with the first quartile (
       
  • In vitro exposure of DE‐71, a penta‐PBDE mixture, on immune
           endpoints in bottlenose dolphins (Tursiops truncatus) and B6C3F1 mice
    • Abstract: Polybrominated diphenyl ethers (PBDEs) are an emerging contaminant of concern with low level exposures demonstrating toxicity in laboratory animals and wildlife, although immunotoxicity studies have been limited. Bottlenose dolphin peripheral blood leukocytes (PBLs) and mouse splenocytes were exposed to environmentally relevant DE‐71 (a penta‐PBDE mixture) concentrations (0–50 µg ml−1) in vitro. Natural killer (NK) cell activity and lymphocyte (B and T cell) proliferation were evaluated using the parallelogram approach for risk assessment. This study aimed to substantiate results from field studies with dolphins, assess the sensitivities between the mouse model and dolphins, and to evaluate risk using the parallelogram approach. In mouse cells, NK cell activity increased at in vitro doses 0.05, 0.5 and 25 µg DE‐71 ml−1, whereas proliferation was not modulated. In dolphin cells, NK cell activity and lymphocyte proliferation was not altered after in vitro exposure. In vitro exposure of dolphin PBLs to DE‐71 showed similar results to correlative field studies; NK cell activity in mice was more sensitive to in vitro exposure than dolphins, and the parallelogram approach showed correlation with all three endpoints to predict risk in bottlenose dolphins. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • Involvement of immune‐ and inflammatory‐related factors in
           flucloxacillin‐induced liver injury in mice
    • Abstract: Drug‐induced liver injury (DILI) is a serious problem in pre‐clinical stages of drug development and clinical pharmacotherapy, but the pathogenesis of DILI has not been elucidated. Flucloxacillin (FLX), which is a β‐lactam antibiotic of the penicillin class that is used widely in Europe and Australia, rarely causes DILI. Clinical features suggest that FLX‐induced liver injury is caused by immune‐ and inflammatory‐related factors, but the mechanism of FLX‐induced liver injury is unknown. The purpose of this study was to elucidate the mechanisms of FLX‐induced liver injury in vivo. Plasma alanine aminotransferase, aspartate aminotransferase and total‐bilirubin levels were significantly elevated in FLX‐administered mice [1000 mg kg–1, intraperitoneally (i.p.)]. Toll‐like receptor 4 (TLR4) ligands, such as high‐mobility group box 1 (HMGB1) and S100A8/A9, were significantly increased in FLX‐administered mice, and inflammatory factors, such as interleukin (IL)‐1β, tumor necrosis factor‐alpha (TNF‐α), macrophage inflammatory protein (MIP)‐2, CXC chemokine‐ligand‐1 (CXCL1) and monocyte chemoattractant protein (MCP)‐1, were also significantly elevated. IL‐17‐related transcriptional factors and cytokines were increased, and the administration of recombinant IL‐17 (2 mg per body weight, i.p.) resulted in an exacerbation of the FLX‐induced liver injury. TLR4‐associated‐signal transduction may be involved in FLX‐induced liver injury, and IL‐17 is an exacerbating factor. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • A trivalent approach for determining in vitro toxicology: Examination of
           oxime K027
    • Abstract: Unforeseen toxic effects contribute to compound attrition during preclinical evaluation and clinical trials. Consequently, there is a need to correlate in vitro toxicity to in vivo and clinical outcomes quickly and effectively. We propose an expedited evaluation of physiological parameters in vitro that will improve the ability to predict in vivo toxicity of potential therapeutics. By monitoring metabolism, mitochondrial physiology and cell viability, our approach provides insight to the extent of drug toxicity in vitro. To implement our approach, we used human hepatocellular carcinoma cells (HepG2) and neuroblastoma cells (SH‐SY5Y) to monitor hepato‐ and neurotoxicity of the experimental oxime K027. We utilized a trivalent approach to measure metabolism, mitochondrial stress and induction of apoptosis in 96‐well formats. Any change in these three areas may suggest drug‐induced toxicity in vivo. K027 and pralidoxime, an oxime currently in clinical use, had no effect on glycolysis or oxygen consumption in HepG2 and SH‐SY5Y cells. Similarly, these oximes did not induce oxidant generation nor alter mitochondrial membrane potential. Further, K027 and pralidoxime failed to activate effector caspases, and these oximes did not alter viability. The chemotherapeutic agent, docetaxel, negatively affected metabolism, mitochondrial physiology and viability. Our studies present a streamlined high‐throughput trivalent approach for predicting toxicity in vitro, and this approach reveals that K027 has no measurable hepatotoxicity or neurotoxicity in vitro, which correlates with their in vivo data. This approach could eliminate toxic drugs from consideration for in vivo preclinical evaluation faster than existing toxicity prediction panels and ultimately prevent unnecessary experimentation. Copyright © 2014 John Wiley & Sons, Ltd.
       
  • Tl(I) and Tl(III) alter the expression of EGF‐dependent signals and
           cyclins required for pheochromocytoma (PC12) cell‐cycle resumption
           and progression
    • Abstract: The effects of thallium [Tl(I) and Tl(III)] on the PC12 cell cycle were evaluated without (EGF−) or with (EGF+) media supplementation with epidermal growth factor (EGF). The following markers of cell‐cycle phases were analyzed: cyclin D1 (G1); E2F‐1, cyclin E and cytosolic p21 (G1→S transition); nuclear PCNA and cyclin A (S); and cyclin B1 (G2). The amount of cells in each phase and the activation of the signaling cascade triggered by EGF were also analyzed. Tl(I) and Tl(III) (5–100 μM) caused dissimilar effects on PC12 cell proliferation. In EGF− cells, Tl(I) increased the expression of G1→S transition markers and nuclear PCNA, without affecting cyclin A or cyclin B1. In addition to those, cyclin B1 was also increased in EGF+ cells. In EGF− cells, Tl(III) increased the expression of cyclin D1, all the G1→S and S phase markers and cyclin B1. In EGF+ cells, Tl(III) increased cyclin D1 expression and decreased all the markers of G1→S transition and the S phase. Even when these cations did not induce the activation of EGF receptor (EGFR) in EGF− cells, they promoted the phosphorylation of ERK1/2 and Akt. In the presence of EGF, the cations anticipated EGFR phosphorylation without affecting the kinetics of EGF‐dependent ERK1/2 and Akt phosphorylation. Altogether, results indicate that Tl(I) promoted cell proliferation in both EGF− and EGF+ cells. In contrast, Tl(III) promoted the proliferation of EGF− cells but delayed it in EGF+ cells, which may be related to the toxic effects of this cation in PC12 cells. Copyright © 2014 John Wiley & Sons, Ltd.
       
 
 
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