Larkinblock3611

The method described in the present study was deemed feasible in determining the particle-size distribution of BDE-209 from vaporization sources and helpful to understanding the instinct rule of particle-size distribution of BDE-209, and potentially feasible for other SVOCs.To evaluate the genotoxic and physiological effects of acute hypoxia on the pacific white shrimp (L. vannamei), shrimps were treated firstly with three dissolved oxygen levels 6.5 ppm (control), 3.0 ppm and 1.5 ppm for 24 h, respectively, and then reoxygenated (6.5 ppm) for 24 h. The changes of superoxide dismutase (SOD) activity, glutathione peroxidases (GPX) activity, malondialdehyde (MDA) concentration and DNA damage in the tissues of gill, hepatopancreas and hemolymph were examined during the period of hypoxia and reoxygenation. The results indicated SOD activity, GPX activity, MDA concentration and DNA damage all increased basically compared with the control during the period of hypoxia except for MDA concentrations in the gill at 12 h and 24 h hypoxia (3.0 ppm), and these parameters were recovered to some degree during the period of reoxygenation. Moreover, the comet assays in the tissues of gill and hepatopancreas showed an obvious time- and dose-dependent response to hypoxia, which indicated comet assay in the two tissues could be used as sensitive biomarker to detect the occurrence of hypoxia. We conclude that acute hypoxia can induce oxidative stress, DNA damage and lipid peroxidation in the tissues of gill, hepatopancreas and hemolymph of L. vannamei and the DNA damage may come from hypoxia-induced oxidative stress.The use of cell lines to test the toxicity of aquatic pollutants is a valuable alternative to fish bioassays. In this study, fibroblast SAF-1 cells from the marine gilthead seabream (Sparus aurata L.) were exposed for 24 h to the heavy metals Cd, Hg, MeHg (Methylmercury), As or Pb and the resulting cytotoxicity was assessed. Neutral red (NR), MTT-tetrazolio (MTT), crystal violet (CV) and lactate dehydrogenase (LDH) viability tests showed that SAF-1 cells exposed to the above heavy metals produced a dose-dependent reduction in the number of viable cells. Methylmercury showed the highest toxicity (EC50 = 0.01 mM) followed by As, Cd, Hg and Pb. NR was the most sensitive method followed by MTT, CV and LDH. SAF-1 cells incubated with each of the heavy metals also exhibited an increase in the production of reactive oxygen species and apoptosis cell death. Moreover, the corresponding gene expression profiles pointed to the induction of the metallothionein protective system, cellular and oxidative stress and apoptosis after heavy metal exposure for 24 h. This report describes and compares tools for evaluating the potential effects of marine contamination using the SAF-1 cell line.Benzo(a)pyrene (BaP) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants and environmental estrogens (EEs) with known toxicity towards the green mussel, Perna viridis. Ertugliflozin In this study, the toxic effects of BaP (10 µg/L) and DDT (10 µg/L) and their mixture were assessed in green mussel gills with proteomic and metabolomic approaches. Metabolic responses indicated that BaP mainly caused disturbance in osmotic regulation by significantly decrease in branched chain amino acids, dimethylamine and dimethylglycine in gills of male green mussels after exposure for 7 days. DDT mainly caused disturbance in osmotic regulation and energy metabolism by differential alteration of betaine, dimethylamine, dimethylglycine, amino acids, and succinate in gills of male green mussels. However, the mixture of BaP and DDT didn't show obvious metabolite changes. Proteomic analysis showed different protein expression profiles between different treatment groups, which demonstrated that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced cell apoptosis, disturbance in protein digestion and energy metabolism in gills of green mussels, whereas DDT exposure altered proteins that were associated with oxidative stress, cytoskeleton and cell structure, protein digestion and energy metabolism. However, the mixture of BaP and DDT affected proteins related to the oxidative stress, cytoskeleton and cell structure, protein biosynthesis and modification, energy metabolism, growth and apoptosis.Illicit drugs have been recognized as emerging aquatic pollutants due to their presence in aquatic ecosystems up to µg/L level. Among these, the synthetic psycho-stimulant drug amphetamine (AMPH) is commonly found in both surface and wastewaters worldwide. Even though the environmental occurrence of AMPH is well-known, the information on its toxicity towards non-target freshwater organisms is completely lacking. This study investigated the imbalance of the oxidative status and both oxidative and genetic damage induced by a 14-day exposure to two concentrations (500 ng/L and 5000 ng/L) of AMPH on the freshwater bivalve Dreissena polymorpha by the application of a biomarker suite. We investigated the activity of antioxidant enzymes (SOD, CAT and GPx), the phase II detoxifying enzyme GST, the lipid peroxidation level (LPO) and protein carbonyl content (PCC), as well as primary (Single Cell Gel Electrophoresis assay) and fixed (DNA diffusion assay and Micronucleus test) genetic damage. Our results showed that a current realistic AMPH concentration (500 ng/L) did neither cause notable imbalances in enzymatic activities, nor oxidative and genetic damage to cellular macromolecules. In contrast, the bell-shaped trend of antioxidants showed at the highest tested concentration (5000 ng/L) suggested an overproduction of reactive oxygen species, leading to oxidative damage, as confirmed by the significant increase of protein carbonylation and DNA fragmentation.Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment.Transcriptomic analysis can complement traditional ecotoxicology data by providing mechanistic insight, and by identifying sub-lethal organismal responses and contaminant classes underlying observed toxicity. Before transcriptomic information can be used in monitoring and risk assessment, it is necessary to determine its reproducibility and detect key steps impacting the reliable identification of differentially expressed genes. A custom 15K-probe microarray was used to conduct transcriptomics analyses across six laboratories with estuarine amphipods exposed to cyfluthrin-spiked or control sediments (10 days). Two sample types were generated, one consisted of total RNA extracts (Ex) from exposed and control samples (extracted by one laboratory) and the other consisted of exposed and control whole body amphipods (WB) from which each laboratory extracted RNA. Our findings indicate that gene expression microarray results are repeatable. Differentially expressed data had a higher degree of repeatability across all laboratories in samples with similar RNA quality (Ex) when compared to WB samples with more variable RNA quality. Despite such variability a subset of genes were consistently identified as differentially expressed across all laboratories and sample types. We found that the differences among the individual laboratory results can be attributed to several factors including RNA quality and technical expertise, but the overall results can be improved by following consistent protocols and with appropriate training.We evaluated the potential for biomagnification of endocrine disrupting chemicals (EDCs) such as nonylphenol (NP), octylphenol (OP), bisphenol A (BP), and natural estrogens such as estrone (E1) and 17β-estradiol (E2) in a benthic fish, Pleuronectes yokohamae. The assimilation efficiencies (AE) of most EDCs ranged from 88 to 96% suggesting that they were efficiently incorporated and assimilated into P. yokohamae, except for NP (50%). However, the biomagnification factor (BMF) values were less then 1.0 suggesting that the compounds were not biomagnifying. Additionally, three of the target EDCs were not detected (BP, E1 and E2). Glucuronidation activity towards BP (11.44 ± 2.5 nmol/mg protein/min) and E2 (12.41 ± 3.2 nmol/mg protein/min) was high in the intestine suggesting that EDCs were glucuronidated prior to excretion into bile. Thus, we conclude that biomagnification of dietary EDCs is reduced in P. yokohamae because of effective glucuronidation.In this study, the effects of cultivation conditions on the degradation of chlorimuron-ethyl by Stenotrophomonas maltophilia D310-3, which exhibits a high chlorimuron-ethyl-degrading capability, were investigated. To improve the biodegradation efficiency, the cultivation conditions were optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). The maximum biodegradation rate (89.9%) was obtained at the optimal conditions (culture time, 6 d; substrate concentration, 50.21 mg L(-1); pH, 5.95; temperature, 30.15 °C). The Andrews model was used to describe the dynamic change regularity of the specific degradation rate as the substrate concentration increased, and the values of the maximum specific degradation rate (q(max)), half-saturation constant (K(S)) and inhibition constant (K(i)) were 78.87 d(-1), 9180.97 mg L(-1) and 0.28 mg L(-1), respectively. Eight degradation products were captured and identified by liquid chromatography-mass spectrometry (LC-MS) and Fourier transform infrared (FTIR) spectrometry, and three possible degradation pathways are proposed based on the results of high-performance liquid chromatography (HPLC), LC-MS and FTIR analyses as well as results reported in relevant literature. To the best of our knowledge, this is the first systematic study of the degradation pathway of chlorimuron-ethyl by S. maltophilia D310-3. This study provides valuable information for further exploration of the microbial degradation of other sulfonylurea herbicides.