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Toxicant exposure

Bice S Martincigh, Moses A Ollengo
The photostabilizing ability of grape seed extract on three common sunscreen absorbers: 2-ethylhexyl-p-methoxcinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract...
October 19, 2016: Photochemistry and Photobiology
Takashi Ishida, Sachie Suzuki, Chen-Yi Lai, Satoshi Yamazaki, Shigeru Kakuta, Yoichiro Iwakura, Masanori Nojima, Yasuo Takeuchi, Masaaki Higashihara, Hiromitsu Nakauchi, Makoto Otsu
Hematopoietic stem cell (HSC) transplantation (HSCT) for malignancy requires toxic pre-conditioning to maximize anti-tumor effects and donor-HSC engraftment. While this induces bone marrow (BM)-localized inflammation, how this BM environmental change affects transplanted HSCs in vivo remains largely unknown. We here report that, depending on interval between irradiation and HSCT, residence within lethally irradiated recipient BM compromises donor-HSC reconstitution ability. Both in vivo and in vitro we demonstrate that, among inflammatory cytokines, TNF-α plays a role in HSC damage: TNF-α stimulation leads to accumulation of reactive oxygen species (ROS) in highly purified hematopoietic stem/progenitor cells (HSCs/HSPCs)...
October 18, 2016: Stem Cells
Melissa Whitfield Aslund, Michael Winchell, Lisa Bowers, Sean McGee, Jane Tang, Lauren Padilla, Colleen Greer, Loren Knopper, Dwayne R J Moore
A probabilistic ecological risk assessment (ERA) was conducted to determine the potential effects of acute and chronic exposure of aquatic invertebrate communities to imidacloprid arising from labeled agricultural and non-agricultural uses in the United States. Aquatic exposure estimates were derived using a higher tier refined modeling approach that accounts for realistic variability in environmental and agronomic factors. Toxicity was assessed using refined acute and chronic community-level effect metrics for aquatic invertebrates (i...
October 18, 2016: Environmental Toxicology and Chemistry
J Machado, J Azevedo, M Freitas, E Pinto, A Almeida, V Vasconcelos, A Campos
Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation...
October 18, 2016: Environmental Science and Pollution Research International
Alessio Ippolito, Roberto Giacchini, Paolo Parenti, Marco Vighi
Biomarkers have been widely employed in ecotoxicology as early warning indicators of exposure to toxicants. Very often, they are used to compare reference and polluted sites, or to analyse time trends. However, very few studies focus on the natural variability range of biomarkers in the environment, which is pivotal to understand if the detected differences are actually determined by any adverse effects due to pollution. This work assesses the natural spatio-temporal variability of some enzymatic levels, frequently used as biomarkers, in freshwater benthic invertebrates...
October 18, 2016: Environmental Science and Pollution Research International
Ravdeep Kaur, Poonam Yadav, Ashwani Kumar Thukral, Amandeep Walia, Renu Bhardwaj
Plant growth regulator-assisted phytoremediation has been assessed as a novel strategy to improve phytoremediation potential of plants. In the present work, potential of castasterone, a plant growth regulator, combined with citric acid was explored for phytoremediation of cadmium in Brassica juncea seedlings. The seedlings were raised under controlled laboratory conditions for 7 days. Results revealed that 0.6 mM cadmium exposure induced toxicity in the seedlings, which was reflected through root growth inhibition, accumulation of hydrogen peroxide and malondialdehyde, and loss of cell viability...
October 17, 2016: Environmental Science and Pollution Research International
Christina Jiun-Yu Tan, Grant E Sklar
INTRODUCTION: Paracetamol is the most common pharmaceutical agent implicated in toxic exposure in Singapore. This study aimed to describe the characteristics of paracetamol overdose in the adult population managed at a tertiary healthcare facility in Singapore. METHODS: Medical records of adult patients hospitalised with a diagnosis of paracetamol overdose at National University Hospital, Singapore, over a three-year period from January 2011 to December 2013 were retrospectively reviewed...
October 18, 2016: Singapore Medical Journal
Katharina Kaufmann, Peter Dohmen
BACKGROUND: Literature data indicate that terrestrial life stages of amphibians may be more sensitive to xenobiotics than birds or mammals. It is hypothesized that dermal exposure could potentially be a significant route of exposure for amphibians, as there is evidence that their skin is more permeable than the skin of other vertebrate species. Thus, higher amounts of xenobiotics might enter systemic circulation by dermal uptake resulting in adverse effects. Heretofore, no guidelines exist to investigate dermal toxicity of chemicals to amphibians...
2016: Environmental Sciences Europe
Ihssane El Bouchikhi, Laila Bouguenouch, Fatima Zohra Moufid, Mohammed Iraqui Houssaini, Khadija Belhassan, Imane Samri, Ayoub Tahri Joutei, Karim Ouldim, Samir Atmani
OBJECTIVE: Secundum atrial septal defect (ASDII) has multifactorial etiology that is combination of environmental (e.g., mother's exposure to toxicity, ethnicity) and genetic causes. Aim of the present study was to screen a Moroccan population with ASDII for NKX2-5 variants and to assess risk factors that may contribute to emergence of the disorder. METHODS: Thirty-two non-syndromic ASDII patients were screened for NKX2-5 variants using direct sequencing of polymerase chain reactionamplified coding regions...
October 12, 2016: Anatolian Journal of Cardiology
A Krigel, M Berdugo, E Picard, R Levy-Boukris, I Jaadane, L Jonet, M Dernigoghossian, C Andrieu-Soler, A Torriglia, F Behar-Cohen
To save energy, the European directives from the Eco-design of Energy Using Products (2005/32/CE) has recommended the replacement of incandescent lamps by more economic devices such as Light Emitting Diodes (LEDs). However, the emission spectrum of these devices is enriched in blue radiations, known to be potentially dangerous to the retina. Recent studies showed that light exposure contribute to the onset of early stages of Age related macular degeneration (AMD). Here, we investigate, in albinos and pigmented rats, the effects of different exposure protocols...
October 14, 2016: Neuroscience
Hiroshi Yamazaki
Research over the past 30 years has elucidated the roles of polymorphic human liver cytochrome P450 (P450) enzymes associated with toxicological and/or pharmacological actions. Thalidomide exerts its various pharmacological and toxic actions in primates through multiple mechanisms, including nonspecific modification of many protein networks after bioactivation by autoinduced human P450 enzymes. To overcome species-differences between rodents, currently, nonhuman primates and/or mouse models with transplanted human hepatocytes are used...
October 17, 2016: Chemical Research in Toxicology
Yanqin Ma, Zhenhua Ma, Shuqin Yin, Xiaoyan Yan, Jundong Wang
Excessive amount of inorganic arsenic (iAs) and fluoride (F) coexist in drinking water in many regions, which is associated with high risk of vascular diseases. However, the underlying mechanisms are not well studied. The present study was to evaluate the effects of iAs and F individual or combined exposure on endothelial activation and apoptosis in vitro. Primary human umbilical vein endothelial cells (HUVECs) were exposed to 5 μM As2O3 and/or 1 mM NaF. Changes in endothelial cell apoptosis, inflammation, oxidative stress and nitric oxide (NO) production were analyzed...
October 14, 2016: Chemosphere
Pablo Pena Gandara E Silva, Caio Rodrigues Nobre, Pryscila Resaffe, Camilo Dias Seabra Pereira, Felipe Gusmão
Microplastic debris is a pervasive type of contaminant in marine ecosystems, being considered a major threat to marine biota. One of the problems of microplastics is that they can adsorb contaminants in extremely high concentrations. When released from the particle, these contaminants have the potential to cause toxic effects in the biota. So far, reports of toxic effects are mostly linked with the direct exposure of organisms through ingestion of contaminated microplastics. There is little information on the toxicity of leachates from microplastics to marine organisms...
October 8, 2016: Water Research
Hassan Mirmonsef, Hanne D Hornum, John Jensen, Martin Holmstrup
Contaminated soil is a problem throughout the industrialized world, and a significant proportion of these sites are polluted with heavy metals such as copper. Ecological risk assessment of contaminated sites requires ecotoxicological studies with spiked soils as well as in-situ ecological observations. Here, we report laboratory and field assessment of copper toxicity for earthworms at a Danish site (Hygum) exclusively contaminated with an increasing gradient in copper from background to highly toxic levels (>1000mgkg(-1) dry soil)...
October 14, 2016: Ecotoxicology and Environmental Safety
Fábio de Melo Tarouco, Filipe Guilherme Andrade de Godoi, Robson Rabelo Velasques, Amanda da Silveira Guerreiro, Marcio Alberto Geihs, Carlos Eduardo da Rosa
Glyphosate based herbicides, including Roundup, are widely employed in agriculture and urban spaces. The objective of this study was to evaluate the toxicological effects of Roundup on the estuarine polychaeta Laeonereis acuta. Biomarkers of oxidative stress as well as acetylcholinesterase and propionilcholinesterase activities were analyzed. Firstly, the LC50 96h for L. acuta was established (8.19mg/L). After, the animals were exposed to two Roundup concentrations: 3.25mg/L (non-observed effect concentration - NOEC) and 5...
October 14, 2016: Ecotoxicology and Environmental Safety
Jone Corrales, Lauren A Kristofco, W Baylor Steele, Gavin N Saari, Jakub Kostal, Edward Spencer Williams, Margaret Mills, Evan P Gallagher, Terrance J Kavanagh, Nancy Simcox, Longzhu Q Shen, Fjodor Melnikov, Julie B Zimmerman, Adelina M Voutchkova-Kostal, Paul T Anastas, Bryan W Brooks
Sustainable molecular design of less hazardous chemicals presents a potentially transformative approach to protect public health and the environment. Relationships between molecular descriptors and toxicity thresholds previously identified the octanol-water distribution coefficient, log D, and the HOMO-LUMO energy gap, ∆E, as two useful properties in the identification of reduced aquatic toxicity. To determine whether these two property-based guidelines are applicable to sublethal oxidative stress (OS) responses, two common aquatic in vivo models, the fathead minnow (Pimephales promelas) and zebrafish (Danio rerio), were employed to examine traditional biochemical biomarkers (lipid peroxidation, DNA damage, total glutathione) and antioxidant gene activation following exposure to eight structurally diverse industrial chemicals (bisphenol A, cumene hydroperoxide, dinoseb, hydroquinone, indene, perfluorooctanoic acid, R-(-)-carvone, tert-butyl hydroperoxide)...
October 17, 2016: Chemical Research in Toxicology
Xuejing Cui, Bin Wan, Liang-Hong Guo, Yu Yang, Xiao-Min Ren
Co-existence of nanomaterials and environmental pollutants requires in-depth understanding of combined toxicity and underlying mechanism. In this work, we found that co-exposure to the mixture of non-cytotoxic level of single-walled carbon nanotubes (SWCNTs) (10 µg/mL) and Ni2+ (20 µM) induced significant cytotoxicity in macrophages. However, almost equal amount of intracellular Ni2+ was detected after Ni2+/SWCNT co-exposure or Ni2+ single exposure, indicating no enhanced cellular uptake of Ni2+ occurred...
October 17, 2016: Environmental Science & Technology
Ling C Huang, Mercedes Salvador-Silva, Ronika S Leang
OBJECTIVES: To demonstrate correlations among in vitro assays used for assessing cytotoxicity of contact lens multipurpose solution (MPS) and propose the use of multiple assays as a part of preclinical evaluation for MPS biocompatibility assessment. METHODS: The effect of four different MPSs on cell cytotoxicity, metabolic activity, and membrane integrity was performed by evaluating toxicity, expression of tight junction protein zonula occludens-1, and transepithelial electrical resistance in human corneal epithelial cells and Chinese hamster fibroblasts cells...
October 3, 2016: Eye & Contact Lens
Imed-Eddine Kadi, Faouzi Dahdouh
Nickel is an abundant carcinogenic and nephrotoxic metal whose activity leads to renal impairment. Previous studies have shown a protective effect of simultaneous vitamin C administration on acute and chronic nickel toxicity. However, very little research relating to the effect of vitamin C pretreatment in preventing nickel-induced acute nephrotoxicity is available. Therefore, the present study aimed to determine the efficiency of vitamin C (VC) pretreatment in preventing acute renal toxicity of nickel. Mice were pretreated orally with vitamin C (16...
September 1, 2016: Arhiv za Higijenu Rada i Toksikologiju
Ying Peng, Pu Xia, Junjiang Zhang, Daniel L Villeneuve, Jiamin Zhang, Zhihao Wang, Si Wei, Hongxia Yu, Xiaowei Zhang
Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are analogs of PBDEs with hundreds of possible structures and are frequently detected in the environment. However, the in vivo evidence on the toxicity of OH-PBDEs is still very limited. Here the developmental toxicity of 6-OH-BDE47, a predominant congener of OH-PBDEs detected in the environment, in chicken embryos was assessed using a toxicogenomic approach. Fertilized chicken eggs were dosed via in ovo administration of 0.006 to 0.474 nmol 6-OH-BDE47/g egg followed by 18-days incubation...
October 17, 2016: Environmental Science & Technology
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