bluuebunny/crossref_metadata_2025_split huggingface dataset:
Desorption and biodegradation of sorbed styrene in soil and aquifer solids
Authors: Fu Min Hong , Mayton Hilary , Alexander Martin 
Published: March 2010

Abstract
Approximately 40 and 18% of styrene freshly added to Lima loam and aquifer solids, respectively, was mineralized in 50 d Although measurements of equilibrium desorption under abiotic conditions showed that only 7 2 and 5 7% of sorbed styrene were present in aqueous solution at 150 h, 61 0 and 66 7% of the compound were desorbed from the soil and aquifer solids, respectively, in 16 d under nonequihbrium conditions Much of the nondesorbed styrene freshly added to the environ mental samples could be extracted with methanol Approximately 20% of the freshly added styrene not removed from columns of soil that had been repeatedly leached with water was mineralized in 49 d Styrene freshly added to a muck soil also was ex tensively mineralized However, if the compound was in soil for increasingly long periods in the absence of microbial activity, the extent of biodegradation by subsequently added microorganisms became progressively lower until &lt;3% was mineralized in soils in which the chemical was present for four months Most of the styrene freshly added to Lima loam and Edwards muck could be extracted with acetomtrile, but &lt;4% was extracted from soils containing the chemical for 123 d The biodegradation of styrene that has been in natural environments for some time thus is probably different from the transformations that occur with the freshly added compound
Pentachlorophenol: Uptake/elimination kinetics and metabolism in an aquatic plant, Eichhornia Crassipes
Authors: Roy Sashwati , Hänninen Osmo 
Published: March 2010

Abstract
Eichhornia crassipes [(Mart) Solms], an aquatic plant widely used for the treatment of wastewaters, was used to study uptake/elimination kinetics and metabolism of pentachlorophenol (PCP). PCP is a well-known industrial by-product and a major pollutant of the aquatic environment. The initial phase of PCP uptake by the plant was rapid and reached a nearly steady state between 24 and 48 h of exposure to PCP. The major by-products of PCP metabolism in Eichhornia crassipes were identified as ortho- and para- substituted chlorohydroxyphenols (chlorocatechols and -hydroquinones), -anisoles, and -veratroles. Partially dechlorinated products of PCP were also detected. A major portion of the absorbed PCP and metabolites was found in bound/conjugated form. The responses of the enzyme systems involved in the xenobiotic metabolism and antioxidative system were also studied following PCP exposure. A significant increase was observed in the activity of glutathione S-transferase (GST), a major conjugating enzyme, and in the activities of superoxide dismutase and ascorbate peroxidase (Halliwell-Asada pathway enzymes) of PCP exposed plants. Such responses of plant enzymes may be implemented as useful markers of aquatic pollution. The result related to the uptake and metabolism of PCP obtained from the present study suggests a crucial role of aquatic plants in determining the fate of environmental chemicals.
Effect of four environmental toxicants on plasma Ca and estradiol 17β and hepatic P450 in laying hens
Authors: Chen Shu-Wen , Dziuk Philip J. , Francis B. Magnus 
Published: March 2010

Abstract
In a previous study, we found that administration of phenobarbital to laying hens was associated with an increase in content of liver cytochrome P450 and a reduction in concentration of estradiol (E2) in serum Thus, we hypothesized that other xenobiotics such as environmental toxicants that affect P450 might also affect E2 in laying hens In experiment 1, we examined the effect of four environmental pollutants, three of which induce different isoenzymes of P450 and one inhibitor, on circulating E2 and related reproductive functions Aroclor 1254 (PCB), 20 mg/d, dichlorodiphenyltrichloroethane (DDT), 40 mg/d, or benzo[a]pyrene (BZ), 5 mg/d, was administered for 5 d An inhibitor, lead acetate (100 mg in glycerol/salme), was injected for 2 d Controls received corn oil or sodium acetate No significant difference was observed due to administration of lead Treatment with PCB or DDT decreased the concentration of E2 and increased P450 Only PCB significantly decreased plasma total calcium and egg lay Therefore in experiment 2, we determined the dose-response effect of PCB The PCB was given orally at doses of 0, 5, 10, and 25 mg in corn oil for 5 d The depression of concentrations of E2 was associated with the induction of P450 in a dose dependent manner Egg production and plasma total calcium were reduced by the two highest doses, but eggshell thickness was not different from control in all regimens Plasma E2 and plasma total calcium were negatively cor related with induction of P450 BZ is not a strong inducer of P450 and had no effect on E2 or reproduction, whereas DDT and PCB had a profound effect on P450 with consequent depression of circulating E2 These data indicate that the effects of envi ronmental pollutants on reproduction in birds can be mediated through increased P450, thereby increasing the metabolism of steroid hormones and depressing concentration in circulation
Biochemical and toxic effects of polychlorinated biphenyls (PCBs), dibenzo-P-dioxins (PCDDs) and dibenzofurans (PCDFs) in the cormorant (phalacrocorax carbo) after in ovo exposure
Authors: Van Den Berg Martin , Craane Bart L. H. J. , Sinnige Theo , VanMourik Sijmen , Van Der Gaag Marten , Lutke-Schipholt Ineke J. , Spenkelink Bert , Brouwer Abraham , Dirksen Sjoerd , Boudewun Theo 
Published: March 2010

Abstract
Ecological investigations revealed differences in breeding success of cormorants (Phalacrocorax carbo) between two colonies in The Netherlands In this study the possible role of organohalogen pollutants was investigated. Thirty-nine cormorant eggs were collected from two colonies with marked differences in contamination Seventeen cormorant eggs were hatched in an incubator. The respiration rate was monitored regularly during the incubation. Hatchlings were euthanized at day 1 Several morphological parameters were measured PCBs and polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were analyzed in the yolk sac Blood and liver were collected for analysis of cytochrome P450, ethoxyresorufin-O-deethylation (EROD) and pentoxyresorufin-O-depentylation (PROD) activities, vitamin A, and thyroid hormone levels. Residue levels differed two- to five-fold for PCBs and 25% for PCDDs and PCDFs between both colonies Birds from the most contaminated colony showed an increased in ovo respiration rate, increased cytochrome P450 and EROD activity, and reduced plasma thyroid hormone and hepatic retinyl palmitate levels. Large interindividual differences were observed for all parameters The data were compared on an individual basis (n = 17) to detect any concentration-effect relationships. Significant (p &lt; 0 05) concentration-effect relationships were observed for EROD induction, plasma free thyroxine reduction, yolk sac weight, relative liver weight, and head size. It is concluded these compounds may, at least in part, have played a role in the observed low breeding success of cormorants
Flow cytometric determination of the photoinduced toxicity of anthracene to the green algaSelenastrum Capricornutum
Authors: Gala William R. , Giesy John P. 
Published: March 2010

AbstractCertain PAHs are photosensitizers and in the presence of solar radiation can cause toxicity to aquatic plants and animals. The photoinduced toxicity of anthracene to the green alga Selenastrum capncornutum was assessed by the use of flow cytometry to measure cell size, cellular chlorophyll concentration, and cell viability. Anthracene was slightly toxic in the absence of UV-A radiation. The detection of the direct toxicity of anthracene in this study at a concentration of 19 μg/L anthracene resulted from the use of sensitive flow cytometric measures. There was a significant interaction between anthracene and UV-A radiation, which, in combination, caused significant toxic effects on Selenastrum capncornutum. The most sensitive flow cytometric measure of toxicity was the stress index (SI), which was predictive of longer term effects on cell growth. The 28-h EC50 and EC10 for the SI for Selenastrum capncornutum were 16.1 and 8.3 μg/L anthracene, respectively, at 125 μW/cm2 UV-A. All combinations of anthracene and UV-A that inhibited algal growth also caused a significantly greater number of nonviable cells. The flow cytometric methods used in this study proved to be sensitive, predictive measures of the direct and photo-induced toxicity of anthracene and UV-A radiation to Selenastrum capricornutum.
Quantitative structure-activity relationships for toxicity of phenols using regression analysis and computational neural networks
Authors: Xu Lu , Ball J.W. , Dixon S.L. , Jurs P.C. 
Published: March 2010

Abstract
Quantitative structure-toxicity models were developed that directly link the molecular structures of a set of 50 alkylated and/or halogenated phenols with their polar narcosis toxicity, expressed as the negative logarithm of the IGC50 (50% growth inhibitory concentration) value in millimoles per liter. Regression analysis and fully connected, feed-forward neural networks were used to develop the models. Two neural network training algorithms (back-propagation and a quasi-Newton method) were employed. The best model was a quasi-Newton neural network that had a root-mean-square error of 0.070 log units for the 45 training set phenols and 0.069 log units for the five cross-validation set phenols.
Biodegradation of chlorobenzene by indigenous bacteria
Authors: Nishino Shirley F. , Spain Jim C. , Pettigrew Charles A. 
Published: March 2010

Abstract
Soil and ground water from four sites chronically contaminated with chlorobenzenes were examined to determine whether indigenous bacteria could degrade the contaminants and whether the addition of specific chlorobenzene-degrading bacteria enhanced the degradation rate At each site, chlorobenzene-degrading bacteria were readily isolated from chlorobenzene contaminated wells, whereas similar samples from noncontammated wells yielded no chlorobenzene degrading bacteria Isolates were tested for growth on a variety of substrates At a site contaminated with several solvents, a bioreactor was inoculated with the chlorobenzene degrading Pseudomonas sp strain JS150 Contaminated water was pumped through this bioreactor and a control bioreactor that had been colonized by indigenous microorganisms The contaminants were removed from both bioreactors, however, JS150 could not be recovered from the inoculated bioreactor after three weeks of operation A follow up lab study using ground water from the contaminated site confirmed the field results We conclude that chlorobenzene contamination of soil causes the development of indigenous degradative populations that have a competitive advantage over inoculated strains The mechanism and time course of this acclimation are poorly understood and require additional study
Photolysis of smoke dyes on soils
Authors: Adams Rebecca L. , Weber Eric J. , Baughman George L. 
Published: March 2010

Abstract
Photolysis of an azo, a quinophthalone, and several anthraquinone smoke dyes was studied on soil surfaces. Initially, rapid photodegradation of each dye occurred, followed by a period of much slower rate of loss, indicating that the remaining fraction of the dye was photochemicaily protected. The average mean depths of photolysis ranged from 0.33 to 0.68 mm for outdoor studies and from 0.42 to 0.73 mm for lab studies. The magnitude of the mean depths of photolysis suggests that photo-degradation of the dyes occurs through indirect photochemical processes. Photolysis products for only two of the dyes could be identified. Photolysis of Disperse Red 9 resulted in the formation of 1-aminoanthraquinone, whereas Solvent Yellow 33 photo-degraded to give 2-carboxyquinoline and phthalic anhydride. Reaction mechanisms involving sensitized photo-oxidation by singlet oxygen are consistent with the formation of these reaction products.
Refinery water (intake and effluent) quality: Update of 1970s with 1990s toxicity testing
Authors: Chapman Peter M. , Paine Michael D. , Moran Tim , Kierstead Ted 
Published: March 2010

Abstract
The quality of two separate refinery intake waters and effluents was investigated Petro Canada (Oakville) and Novacor (Corunna Operations) This study comprised eight different test organisms and 22 different toxicity end points, was built on and complemented pioneering 1970s work at the Petro Canada refinery, and was designed to (a) determine any changes in effluent quality, (b) determine any previously unsuspected effluent toxicity, and (c) determine any potential for chronic toxicity in the effluent Although Petro Canada has steadily reduced contaminants in its effluent since the earlier study, toxicity has not changed and no new toxic effects were identified Effect thresholds for the most sensitive animal species (Daphma pulex) were 1 to 10% effluent in both studies The Novacor effluent had lesser effects on biota than the Petro-Canada effluent In take waters demonstrated toxicity in some tests Chronic effects on invertebrates and fish in receiving waters are predicted not to occur if the Novacor effluent is diluted 10- to 20 fold and the Petro Canada effluent is diluted 50- to 100 fold
Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests
Authors: Reynoldson T.B. , Day K.E. , Clarke C. , Milani D. 
Published: March 2010

AbstractSediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P ≥ 0.05) but did reduce growth in all three test species and in two species at the lowest tested densities, equivalent to 1,460 worms per square meter. At densities of Tubifex tubifex equivalent to 20,000 m−2, the growth of Chironomus riparius was reduced by &gt;90%, Hyalella azteca by &gt;60%, and Hexagenia limbata by almost 50%. The densities of oligochaetes are equivalent to those found in many contaminated sites. Therefore, it is concluded that the presence of indigenous organisms can confound the interpretation of toxicity test results, based on chronic end points. It is recommended that removal of organisms be considered before toxicity tests are conducted with freshwater sediments from sites with large populations of benthic invertebrates, especially oligochaete worms.
Expert-system comparison of structural determinants of chemical toxicity to environmental bacteria
Authors: Pangrekar Jyotsna , Rosenkranz Herbert S. , Klopman Gilles 
Published: March 2010

AbstractThe CASE (computer automated structure evaluation) structure-activity relational expert system was used to analyze the toxicity of a database of chemical sets to environmental bacteria (aerobic heterotrophs, nitrosomonas, methanogens, and photobacteria [Microtox® test]). The analyses revealed that the data sets related to each of the antimicrobial activities, albeit containing a relatively small number of chemicals, are characterized by structural determinants significantly associated with the probability of antimicrobial activity, as well as with antibacterial potency. Although there were a number of similarities among the structural determinants associated with each of these antimicrobial activities, there were also features unique to each assay that presumably reflect species-specific targets of bactericidal activity. Overall the assay for antimethanogenic activity appears to be the most informative as well as the one most predictive of the activity in the other three assays.
Identification of multiple steroid hydroxylases inDaphnia magnaand their modulation by xenobiotics
Authors: Baldwin William S. , Leblanc Gerald A. 
Published: March 2010

AbstractSteroid hydroxylase activities were characterized in Daphnia magna and evaluated for potential use as biomarkers of xenobiotic exposure. Microsomes prepared from Daphma magna generated a single NADPH-dependent metabolite of [14C]testosterone. However, intact daphnids excreted at least 10 polar metabolites of [l4C]testosterone into the test medium. Six of these metabolites were identified as 2α-, 16β-, 6β-, 6α-, 7α-, and 15α-[14C]hydroxytestosterone. The unidentified metabolites are also presumed to be hydroxylated products of testosterone, based on their relative migrations during TLC. The inefficient metabolism of [14C]testosterone during the in vitro microsomal incubations may have been due to the release of P450 inhibitors during microsome preparation. Exposure of daphnids to the P450 modulators phenobarbital, β-naphthoflavone, piperonyl butoxide, and malathion differentially inhibited the steroid hydroxylase activities. Results from this study indicate that Daphma magna expresses several P450 enzymes and that these enzymes are differentially modulated by xenobiotic exposure. Steroid hydroxylase activities may serve not only as a biomarker of toxicant exposure, but also as a predictor of toxicant effects involving perturbations of steroid hormone homeostasis.
Volatile halocarbons as tracers of pulp mill effluent plumes
Authors: Comba M.E. , Palabrica V.S. , Kaiser K.L.E. 
Published: March 2010

AbstractThis work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloro-methane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. In the fall, the colder effluent plume sinks into the hypolim-nion and is confined by a bay/lake water-density gradient. In the specific case at hand, the distribution patterns of chloroform and a brominated analog, bromodichloromethane, also suggest the release of chloroform from sediments in the bay.
Survey of receiving-water environmental impacts associated with discharges from pulp mills: 3. Polychlorinated dioxins and furans in muscle and liver of white sucker (Catostomus commersoni)
Authors: Servos Mark R. , Huestis Susanv Y. , Whittle D. Michael , Munkittrick Kelly R. , Van Der Kraakv Glen J. 
Published: March 2010

Abstract
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in white sucker liver samples from seven pulp and paper mill sites, and three reference sites in Ontario. The mills included five bleached-kraft mills, with and without secondary treatment, and two sulfite-mechanical mills. 2,3,7,8-T4CDD and 2,3,7,8-T4CDF were the dominant congeners detected in both liver and fillet samples at all of the pulp and paper mill sites, with mean 2,3,7,8-T4CDD toxic equivalent concentrations (TEQs) as high as 124 pg g−1 in liver tissue. Concentrations of PCDDs/PCDFs in liver tissues were severalfold higher than in fillet tissue, but this difference can be accounted for by lipid normalization. Biological information, including liver weight, gonad weight, MFO activity (ethoxyresorufin-O-deethylase, EROD), and plasma sex steroids, was measured on individual fish. There was no relationship between TEQs and condition factor, gonadosomatic index, liver somatic index, or circulating plasma 11-ketotestosterone. A weak negative correlation was observed between circulating plasma testosterone and TEQs. Although there was a positive correlation (r = 0.49, p &lt; 0.001) between MFO activity (EROD) and TEQ, one site with very low chlorine use and low TEQs had EROD activity similar to levels observed at more contaminated sites. This finding, along with recent observations that MFO activity is rapidly cleared in pulp-mill-exposed fish, casts doubt on an exclusive causal relationship between MFO activity and PCDDs/PCDFs at these sites.
Intestinal survival, competition and translocation of biotechnology agents on intranasal exposure of C3H/HeJ mice
Authors: George S. Elizabeth , Kohan Michael J. , Claxton Larry D. , Taylor Maria S. , Brooks Harold G. , Creason John P. 
Published: March 2010

Abstract
Human exposure to environmentally released biotechnology agents may occur. Therefore, it is important to identify adverse health effects associated with this exposure. This study investigates colonization, competition, and translocation of biotechnology agents following intranasal challenge by sublethal doses of the environmental isolates Pseudomonas malto-phdia (BC6) and Pseudomonas aeruginosa (BC16, BC17, BC18, AC869) Two clinical Pseudomonas aeruginosa isolates (PAO1, DG1), are included for comparison. Following intranasal challenge by approximately 106 colony-forming units (cfu), recovery of the dosed strains were determined in C3H/HeJ mice at time intervals in the intestinal tract, mesenteric lymph node (MLN) complex, liver, and spleen. Intestinal bacterial populations also were enumerated. Strains BC6, AC869, DG1, and PAOl were detectable in all three intestinal regions 14 d following treatment. Strain BC17 was cleared 7 d posttreatment Strains BC18 and BC16 were detectable in two of the three intestinal sections A decrease in cecal lactose nonfermenting enteric bacilli was detected in strain BC6-treated mice Translocation of strains BC16, AC869, and PAOl occurred to the MLN, spleen, and liver. Strain BC18 was detectable in the liver, and strains BC17 and DG1 were recovered from both the MLN and the liver Pulmonary challenge can result in intestinal survival, competition and translocation.
Specific cross-reactivity of antibodies raised against two major stress proteins, stress 70 and chaperonin 60, in diverse species
Authors: Sanders B.M. , Martin L.S. , Nakagawa P.A. , Hunter D.A. , Miller S. , Ullrich S.J. 
Published: March 2010

Abstract
Immunoblot analysis using several antibodies raised against two major families of stress proteins, stress 70 and chaperomn 60 (cpn60), which are highly conserved in mammals, was carried out in diverse species often used in environmental research, including molluscs, annelids, crustaceans, echinoderms, and fish The study revealed surprisingly different patterns of antibody cross reactivity among species The monoclonal anti-stress 70 antibody (mAb) C92 was the least cross reactive for all species tested The mAbs anti-stress 70 N27, BRM-22, and 3a3 were more broadly cross reactive, but their binding specificities to stress 70 isoforms in the diverse species tested did not correlate with one another or follow taxonomic lines The polyclonal anti-stress 70 antibody reacted to proteins in the 70 to 74 kDa range in all fish examined and in most invertebrates When a polyclonal antibody (pAb) raised against cpn60 from a moth was used as a probe, specific binding was observed with proteins in the 60 to 64 kDa range in all fish examined and in most invertebrates However, the size and number of isoforms that reacted with the pAb were species specific These data suggest that these two major stress protein families are less highly conserved in invertebrates and fish than in mammals Therefore, to minimize misinterpretation when using antibodies in heterologous assays with species in which the stress response has not been well characterized, it is important to determine which isoforms of stress 70 react with a particular antibody and to take into account the differential regulation of each member of this multigene family