Science.gov

Sample records for remediate carbon tetrachloride

  1. Expedited approach to a carbon tetrachloride spill interim remedial action

    SciTech Connect

    Cowdery, C.; Primrose, A.; Uhland, J.; Castaneda, N.

    1998-07-01

    Monitored natural attenuation was selected as an interim measure for a carbon tetrachloride spill site where source removal or in situ treatment cannot currently be implemented due to the surrounding infrastructure. Rather than delay action until the site is more accessible to an interim action, this more expedited approach would support a final action. Individual Hazard Substance Site (IHSS) 118.1 is a former underground storage tank at Rocky Flats Environmental Technology Site (RFETS) that stored carbon tetrachloride for process use. Inadvertent releases associated with filling and failure of the tank system resulted in an accumulation of carbon tetrachloride in a bedrock depression around a group of former process waste tanks. Access to the source of contamination is obstructed by numerous utilities, the process waste tanks, and other components of the site infrastructure that limit the ability to conduct an effective remedial action. A preremedial field investigation was conducted in September 1997 to identify and delineate the extent of the dense nonaqueous phase liquid (DNAPL) in the subsurface. Data collected from the investigation revealed that natural processes might be limiting the migration of contaminants from the source area.

  2. Carbon tetrachloride

    Integrated Risk Information System (IRIS)

    Carbon tetrachloride ; CASRN 56 - 23 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  3. 30 CFR 56.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Carbon tetrachloride. 56.20005 Section 56.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Carbon tetrachloride. Carbon tetrachloride shall not be used....

  4. 30 CFR 57.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Carbon tetrachloride. 57.20005 Section 57.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20005 Carbon tetrachloride. Carbon tetrachloride shall not be used....

  5. 30 CFR 57.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Carbon tetrachloride. 57.20005 Section 57.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20005 Carbon tetrachloride. Carbon tetrachloride shall not be used....

  6. 30 CFR 56.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Carbon tetrachloride. 56.20005 Section 56.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Carbon tetrachloride. Carbon tetrachloride shall not be used....

  7. 30 CFR 56.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Carbon tetrachloride. 56.20005 Section 56.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Carbon tetrachloride. Carbon tetrachloride shall not be used....

  8. 30 CFR 57.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Carbon tetrachloride. 57.20005 Section 57.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20005 Carbon tetrachloride. Carbon tetrachloride shall not be used....

  9. 30 CFR 57.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Carbon tetrachloride. 57.20005 Section 57.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20005 Carbon tetrachloride. Carbon tetrachloride shall not be used....

  10. 30 CFR 56.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Carbon tetrachloride. 56.20005 Section 56.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Carbon tetrachloride. Carbon tetrachloride shall not be used....

  11. 30 CFR 56.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Carbon tetrachloride. 56.20005 Section 56.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Carbon tetrachloride. Carbon tetrachloride shall not be used....

  12. 30 CFR 57.20005 - Carbon tetrachloride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Carbon tetrachloride. 57.20005 Section 57.20005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20005 Carbon tetrachloride. Carbon tetrachloride shall not be used....

  13. Assessment of Carbon Tetrachloride Groundwater Transport in Support of the Hanford Carbon Tetrachloride Innovative Technology Demonstration Program

    SciTech Connect

    Truex, Michael J.; Murray, Christopher J.; Cole, Charles R.; Cameron, Richard J.; Johnson, Michael D.; Skeen, Rodney S.; Johnson, Christian D.

    2001-07-13

    Groundwater modeling was performed in support of the Hanford Carbon Tetrachloride Innovative Treatment Remediation Demonstration (ITRD) Program. The ITRD program is facilitated by Sandia National Laboratory for the Department of Energy Office of Science and Technology. This report was prepared to document the results of the modeling effort and facilitate discussion of characterization and remediation options for the carbon tetrachloride plume among the ITRD participants. As a first step toward implementation of innovative technologies for remediation of the carbon tetrachloride (CT) plume underlying the 200-West Area, this modeling was performed to provide an indication of the potential impact of the CT source on the compliance boundary approximately 5000 m distant. The primary results of the modeling bracket the amount of CT source that will most likely result in compliance/non-compliance at the boundary and the relative influence of the various modeling parameters.

  14. Carbon tetrachloride under extreme conditions

    SciTech Connect

    Pravica, Michael Sneed, Daniel; Wang, Yonggang; Smith, Quinlan; Subrahmanyam, Garimella

    2014-05-21

    We report on three experiments on carbon tetrachloride subjected to extreme conditions. In the first experiment, Raman spectra of CCl{sub 4} were acquired up to 28 GPa. Evidence was observed for at least two new phases of CCl{sub 4} above 14 GPa (phase VI) and above 22 GPa (phase VII). Decompression of the sample showed no evidence of pressure-induced decomposition. In the second experiment, a synchrotron x-ray diffraction study was performed up to 30 GPa verifying phase V and potential phases above 14 (VI) and 22 GPa (VII), respectively. In the third study, we examined irradiated CCl{sub 4} using synchrotron infrared spectroscopy to reduce fluorescent contamination. Some sort of carbon allotrope appears as a byproduct suggesting the following reaction with hard x-rays: CCl{sub 4}+ hν → C + 2Cl{sub 2}.

  15. Overcoming Barriers to the Remediation of Carbon Tetrachloride through Manipulation of Competing Reaction Mechanisms-Final Technical Report

    SciTech Connect

    Tratnyek, Paul G; Amonette, James E; Bylaska, Eric J

    2007-03-07

    The premise of this project was that if we understood the fundamental chemistry that controls the branching among product formation pathways for the degradation of CCl₄, we could design remediation strategies that minimize the formation of CHCl₃ and thereby provide badly needed alternatives for remediation of the large plumes of CCl₄ that contaminate several DOE sites. To this end, we performed a series of coordinated batch, spectroscopic, and modeling experiments, to study the effect of a variety of factors on the yield of CHCl₃ from CCl₄ during reduction with zero-valent iron (Fe⁰). The factors studied include those with direct implications for field performance (e.g., the concentration of CCl₄ relative to the amount of iron surface area) and others chosen for diagnosis of the reaction mechanism (e.g., incorporation of deuterium into CCl₄ reduction products in the presence of D₂O). The key mechanistic findings of this study are (i) that CCl₃• probably is not an intermediate in the formation of CF, but CCl₃⁻ probably is, (ii) the high reductive capacity of the Fe⁰ core favors the concerted 2e⁻ reduction, and (iii) magnetite on Fe⁰ favors the benign product formation pathway. The latter conclusion is based on the observation that one type of nano-sized Fe⁰ that is coated with magnetite shell produces low yields of chloroform (0-40%), whereas others produce the higher yields of chloroform (60-100%) that are typical of most methods for reducing CCl₄ (including biodegradation). Since nano-Fe⁰ can, in principle, be introduced into the deep subsurface by injection, our results would suggest that the right type of nano-Fe⁰ introduced in the right way might be highly effective at dechlorinating CCl₄ with minimal formation of CHCl₃ or other undesirable by-products. This conclusion may offer a breakthrough in the search for remediation technologies that are suitable for the deep CCl₄-contamination at DOE sites such as the 200-W

  16. A Substitute Foe "Bromine in Carbon Tetrachloride"

    ERIC Educational Resources Information Center

    Daley, Joshua M.; Landolt, Robert G.

    2005-01-01

    The addition of a dilute solution of bromine in carbon tetrachloride to a compound to test for carbon-carbon multiple bonds, which is one of the widely cited qualitative tests employed in organic chemistry is presented. Major advantages of this approach include the ease and rapidness of the procedure, the stability of the test solution over time,…

  17. Improved risk estimates for carbon tetrachloride. 1998 annual progress report

    SciTech Connect

    Benson, J.M.; Springer, D.L.; Thrall, K.D.

    1998-06-01

    'The overall purpose of these studies is to improve the scientific basis for assessing the cancer risk associated with human exposure to carbon tetrachloride. Specifically, the toxicokinetics of inhaled carbon tetrachloride is being determined in rats, mice and hamsters. Species differences in the metabolism of carbon tetrachloride by rats, mice and hamsters is being determined in vivo and in vitro using tissues and microsomes from these rodent species and man. Dose-response relationships will be determined in all studies. The information will be used to improve the current physiologically based pharmacokinetic model for carbon tetrachloride. The authors will also determine whether carbon tetrachloride is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation. In combination, the results of these studies will provide the types of information needed to enable a refined risk estimate for carbon tetrachloride under EPA''s new guidelines for cancer risk assessment.'

  18. Project Work Plan Carbon Tetrachloride and Chloroform Attenuation Parameter Studies: Heterogeneous Hydrolytic Reactions

    SciTech Connect

    Amonette, James E.; Truex, Michael J.; Fruchter, Jonathan S.

    2006-06-01

    Between 1955 and 1973, an estimated 750,000 kg of carbon tetrachloride were discharged to the soil in the 200 West Area of the Hanford Site as part of the plutonium production process. Of this amount, some carbon tetrachloride reached the groundwater more than 70 m below the ground surface and formed a plume of 10 km2. Recent information has shown that the carbon tetrachloride plume extends to a depth of at least 60 m below the water table. Some carbon tetrachloride has been degraded either by the original process or subsequent transformations in the subsurface to form a co-existing chloroform plume. Although current characterization efforts are improving the conceptual model of the source area, more information is needed to effectively assess the fate and transport of carbon tetrachloride and chloroform to support upcoming remediation decisions for the plume. As noted in a simulation study by Truex et al. (2001), parameters describing porosity, sorption, and abiotic degradation have the largest influence on predicted plume behavior. The work proposed herein will improve the ability to predict future plume movement by better quantifying abiotic degradation mechanisms and rates. This effort will help define how much active remediation may be needed and estimate where the plume will eventually stabilize – key factors in determining the most appropriate remedy for the plume.

  19. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR CARBON TETRACHLORIDE

    EPA Science Inventory

    Carbon tetrachloride is a volatile haloalkane with a wide range of industrial and chemical applications. It is produced commercially from chlorination of a variety of low molecular weight hydrocarbons such as carbon disulfide, methanol, methane, propane, and ethylene dichloride....

  20. Extrahepatic sites of metabolism of carbon tetrachloride in rats.

    PubMed

    Tjälve, H; Löfberg, B

    1983-09-15

    Rats were injected i.v. and i.p. with [14C]carbon tetrachloride and the localization and binding of metabolites in the tissues were studied by autoradiography. Based on the autoradiographic findings, various tissues were tested for their capacity to form 14CO2 from [14C]carbon tetrachloride in vitro. Autoradiography in vitro was used to localize the sites of [14C]carbon tetrachloride metabolism under in vitro conditions. The results showed that several tissues accumulating metabolites in vivo had an ability to form 14CO2 in vitro, and accumulation of metabolites was observed also under the in vitro conditions. These results indicate that carbon tetrachloride is metabolized in many extrahepatic tissues in vivo. The structures identified to have a marked carbon tetrachloride-metabolizing capacity were, besides the liver, the mucosa of the bronchial tree, the tracheal mucosa, the olfactory and respiratory nasal mucosa, the oesophageal mucosa, the mucosa of the larynx, the tongue and the cheeks, the lateral nasal gland and the kidney cortex. It is well established that the degradation of carbon tetrachloride involves the cytochrome P-450 system, and the metabolism of the substance in the mentioned tissues is probably correlated to high concentrations of cytochrome P-450. The nasal olfactory mucosa was found to be the tissue with the highest capacity to form 14CO2 from the [14C]carbon tetrachloride and microautoradiography indicated that in this tissue the cells of the subepithelial glands of the lamina propria mucosae are most actively engaged in the metabolism. It was also shown that cytochrome P-450 is present in the nasal olfactory mucosa.

  1. IMPROVED RISK ESTIMATES FOR CARBON TETRACHLORIDE

    SciTech Connect

    Benson, Janet M.; Springer, David L.

    1999-12-31

    Carbon tetrachloride has been used extensively within the DOE nuclear weapons facilities. Rocky Flats was formerly the largest volume consumer of CCl4 in the United States using 5000 gallons in 1977 alone (Ripple, 1992). At the Hanford site, several hundred thousand gallons of CCl4 were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl4 in groundwater at highly contaminated sites at the Hanford facility have exceeded 8 the drinking water standard of 5 ppb by several orders of magnitude (Illman, 1993). High levels of CCl4 at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl4 cleanup required at these sites and associated costs are driven by current human health risk estimates, which assume that CCl4 is a genotoxic carcinogen. The overall purpose of these studies was to improve the scientific basis for assessing the health risk associated with human exposure to CCl4. Specific research objectives of this project were to: (1) compare the rates of CCl4 metabolism by rats, mice and hamsters in vivo and extrapolate those rates to man based on parallel studies on the metabolism of CCl4 by rat, mouse, hamster and human hepatic microsomes in vitro; (2) using hepatic microsome preparations, determine the role of specific cytochrome P450 isoforms in CCl4-mediated toxicity and the effects of repeated inhalation and ingestion of CCl4 on these isoforms; and (3) evaluate the toxicokinetics of inhaled CCl4 in rats, mice and hamsters. This information has been used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). Another major objective of the project was to provide scientific evidence that CCl4, like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing and regenerative proliferation. In

  2. Reductive dechlorination of carbon tetrachloride using buffered alkaline ascorbic acid.

    PubMed

    Lin, Ya-Ting; Liang, Chenju

    2015-10-01

    Alkaline ascorbic acid (AA) was recently discovered as a novel in-situ chemical reduction (ISCR) reagent for remediating chlorinated solvents in the subsurface. For this ISCR process, the maintenance of an alkaline pH is essential. This study investigated the possibility of the reduction of carbon tetrachloride (CT) using alkaline AA solution buffered by phosphate and by NaOH. The results indicated that CT was reduced by AA, and chloroform (CF) was a major byproduct at a phosphate buffered pH of 12. However, CT was completely reduced by AA in 2M NaOH without CF formation. In the presence of iron/soil minerals, iron could be reduced by AA and Fe(2+) tends to precipitate on the mineral surface to accelerate CT degradation. A simultaneous transfer of hydrogenolysis and dichloroelimination would occur under phosphate buffered pH 12. This implies that a high alkaline environment is a crucial factor for maintaining the dominant pathway of two electron transfer from dianionic AA to dehydroascorbic acid, and to undergo dichloroelimination of CT. Moreover, threonic acid and oxalic acid were identified to be the major AA decomposition products in alkaline solutions.

  3. IRIS Toxicological Review of Carbon Tetrachloride (External Review Draft)

    EPA Science Inventory

    EPA conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of carbon tetrachloride that will appear on the Integrated Risk Information System (IRIS) database. Peer review is meant to ensure that science is used credibly and...

  4. IRIS Toxicological Review for Carbon Tetrachloride (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA is releasing the draft report,Toxicological Review for Carbon Tetrachloride, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development...

  5. Hepatic function in workers occupationally exposed to carbon tetrachloride.

    PubMed Central

    Tomenson, J A; Baron, C E; O'Sullivan, J J; Edwards, J C; Stonard, M D; Walker, R J; Fearnley, D M

    1995-01-01

    OBJECTIVES--To identify any differences in hepatic function between workers exposed to carbon tetrachloride and controls, and to identify the best variable with which to examine any effects. METHODS--In a cross sectional study of hepatic function in workers occupationally exposed to carbon tetrachloride, 135 exposed employees were compared with 276 non-exposed controls. The exposed group was taken from three sites in the north west of England and the control group included non-exposed workers from one of these sites and another site located nearby. Demographic and alcohol consumption data were collected from both groups by questionnaire. Each member of the study group was allotted a notional estimated exposure to carbon tetrachloride, calculated from historic personal monitoring data and job category. A fasting sample of blood was taken from all participants and analysed for a variety of biochemical and haematological variables. The techniques of univariate and multivariate analysis of variance were used to investigate the effect on biochemical and haematological indices of a range of factors. RESULTS--Multivariate analysis of variance of four core liver function variables, alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma-glutamyl transferase, showed a significant difference between exposed and non-exposed workers. The univariate analyses identified increases in only alkaline phosphatase and gamma-glutamyl transferase within the exposed group and these did not show a significant dose-response relation. Univariate analysis of variance did show effects of alcohol and age on several variables. Significant differences between exposed and control groups for three haematological variables, haemoglobin, packed cell volume, and red blood count, were thought not to be due to the effects of exposure. Clinical review of exposed subjects with abnormal results did not show clinically evident disease that could have been associated with exposure to

  6. PARTICLE TRACKING ANALYSIS & ANIMATIONS DEPICTING MOVEMENT OF THE CARBON TETRACHLORIDE PLUME REPORT

    SciTech Connect

    MCMAHON, W.J.; ROHAY, V.J.

    2006-11-02

    The purpose of the hydraulic particle tracking animation files is to show where carbon tetrachloride that reached groundwater from the known discharge facilities would have been likely to travel fin the groundwater, and from where carbon tetrachloride presently observed in the aquifer likely would have started. These analyses support the 200-PW-1 Operable Unit activity to identify sources of carbon tetrachloride currently observed in groundwater or locations where carbon tetrachloride may have entered the groundwater. The animation files show travel paths (both forward and backward in time) for hypothetical particles of carbon tetrachloride carried in the groundwater. The travel paths represent the movement of the carbon tetrachloride at the average groundwater velocity. The particles only represent an estimation of where the carbon tetrachloride would be expected to be (or have come from) and do not indicate or imply what the concentration in the groundwater would be.

  7. Degradation of carbon tetrachloride in the presence of zero-valent iron.

    PubMed

    Alvarado, Jorge S; Rose, Candace; Lafreniere, Lorraine

    2010-08-01

    Efforts to achieve the decomposition of carbon tetrachloride through anaerobic and aerobic bioremediation and chemical transformation have met with limited success because of the conditions required and the formation of hazardous intermediates. Recently, particles of zero-valent iron (ZVI) have been used with limited success for in situ remediation of carbon tetrachloride. We studied a modified microparticulate product that combines controlled-release carbon with ZVI for stimulation of in situ chemical reduction of persistent organic compounds in groundwater. With this product, a number of physical, chemical, and microbiological processes were combined to create very strongly reducing conditions that stimulate rapid, complete dechlorination of organic solvents. In principle, the organic component of ZVI microparticles is nutrient rich and hydrophilic and has high surface area capable of supporting the growth of bacteria in the groundwater environment. In our experiments, we found that as the bacteria grew, oxygen was consumed, and the redox potential decreased to values reaching -600 mV. The small modified ZVI particles provide substantial reactive surface area that, in these conditions, directly stimulates chemical dechlorination and cleanup of the contaminated area without accumulation of undesirable breakdown products. The objective of this work was to evaluate the effectiveness of ZVI microparticles in reducing carbon tetrachloride under laboratory and field conditions. Changes in concentrations and in chemical and physical parameters were monitored to determine the role of the organic products in the reductive dechlorination reaction. Laboratory and field studies are presented.

  8. Physiological factors affecting carbon tetrachloride dehalogenation by the denitrifying bacterium Pseudomonas sp. strain KC

    SciTech Connect

    Lewis, T.A.; Crawford, R.L. )

    1993-05-01

    Carbon tetrachloride (CT) is a carcinogenic, ozone-depleting, toxic, xenobiotic compound found in ground water, listed as a priority pollutant by the US EPA. In aqueous solution, CT is not readily hydrolyzed and has an estimated half-life of 7,000 years. Since CT resists spontaneous degradation, conditions favorable for dehalogenation must be created to effect remediation of CT contamination. This paper describes studies of CT transformation aimed at determining the potential of Pseudomonas sp. strain KC as a bioaugmentation strain and describes a search for KC-type CT transformation activity in samples from regional aquifers. 11 refs., 9 figs., 1 tab.

  9. Analytical methods for the determination of carbon tetrachloride in soils.

    SciTech Connect

    Alvarado, J. S.; Spokas, K.; Taylor, J.

    1999-06-01

    Improved methods for the determination of carbon tetrachloride are described. These methods incorporate purge-and-trap concentration of heated dry samples, an improved methanol extraction procedure, and headspace sampling. The methods minimize sample pretreatment, accomplish solvent substitution, and save time. The methanol extraction and headspace sampling procedures improved the method detection limits and yielded better sensitivity, good recoveries, and good performance. Optimization parameters are shown. Results obtained with these techniques are compared for soil samples from contaminated sites.

  10. The Carbon Tetrachloride (CCl4) Budget: Mystery or Not

    NASA Technical Reports Server (NTRS)

    Liang, Qing; Newman, Paul A.; Daniel, John S.; Reimann, Stefan; Hall, Bradley; Dutton, Geoff; Kuijpers, Lambert J. M.

    2014-01-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance and greenhouse gas and has been regulated under the Montreal Protocol. However, atmospheric observations show a very slow decline in CCl4 concentrations, inconsistent with the nearly zero emissions estimate based on the UNEP reported production and feedstock usage in recent years. It is now apparent that there are either unidentified industrial leakages, an unknown production source of CCl4, or large legacy emissions from CCl4 contaminated sites. In this paper we use a global chemistry climate model to assess the budget mystery of atmospheric CCl4. We explore various factors that affect the global trend and the gradient between the Northern and Southern hemispheres or interhemispheric gradient (IHG): emissions, emission hemispheric partitioning, and lifetime variations. We find a present-day emission of 30-50 Gg per yr and a total lifetime 25 - 36 years are necessary to reconcile both the observed CCl4 global trend and IHG.

  11. Abiotic Degradation Rates for Carbon Tetrachloride and Chloroform: Progress in FY2009

    SciTech Connect

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Wietsma, Thomas W.; Truex, Michael J.

    2010-03-31

    This report documents the progress made through FY 2009 on a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater for carbon tetrachloride (CT) and chloroform (CF). The study seeks also to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. In previous years the work was funded as two separate projects by various sponsors, all of whom received their funding from the U.S. Department of Energy (DOE). In FY2009, the projects were combined and funded by CH2MHill Plateau Remediation Corporation (CHPRC). Work in FY2009 was performed by staff at the Pacific Northwest National Laboratory (PNNL). Staff from the State University of New York at Cortland (SUNY–Cortland) contributed in previous years.

  12. FY 93 site characterization status report and data package for the carbon tetrachloride site

    SciTech Connect

    Rohay, V.J.

    1993-09-28

    This report provides the status and accomplishments from fiscal year site characterization activities conducted as part of the 200 West Area Carbon Tetrachloride Expedited Response Action and the Volatile Organic Compounds - Arid Integrated Demonstration. The report includes or references all available raw data collected as part of these tasks. During fiscal year 1993, the 200 West Area Carbon Tetrachloride Expedited Response Action and the Volatile Organic Compounds - Arid Integrated Demonstration programs focused on the carbon tetrachloride plume in the unsaturated zone underlying the 200 West Area at the Hanford Site in southeast Washington.

  13. The potential effects of pomegranate (Punica granatum) juice on carbon tetrachloride-induced nephrotoxicity in rats.

    PubMed

    Abdel Moneim, Ahmed E; El-Khadragy, Manal F

    2013-09-01

    The purpose of this study was to evaluate the effect of pomegranate (Punica granatum) in inhibiting and reversing the nephrotoxicity of carbon tetrachloride, a potent oxidative stress inducer which induces cellular kidney damage. Rats were intraperitoneally injected with carbon tetrachloride (2 mL/kg body weight) which produced severe renal tissue damage, as demonstrated by decreased uric acid and dramatic elevation of urea and creatinine. In addition, carbon tetrachloride injection caused oxidative stress in rats, as evidenced by increased lipid peroxidation and nitrite/nitrate (NO x ) concentrations in the renal tissue, along with a remarkable reduction in superoxide dismutase, catalase, glutathione transferase, glutathione reductase, glutathione peroxidase activities and glutathione content. We suggested that pomegranate juice was able to elevate the antioxidant defense system, clean up free radicals, lessen oxidative damages and protect the kidney against carbon tetrachloride-induced toxicity, thus having a potential protective effect.

  14. Wellfield strategy and recommendations for the 200 West Area carbon tetrachloride expedited response action

    SciTech Connect

    Rohay, V.J.

    1994-04-01

    On December 20, 1990, the US Environmental Protection Agency (EPA) and the Washington State Department of Ecology (Ecology) requested the US Department of Energy (DOE), Richland Field Office (RL) to proceed with the detailed planning, including nonintrusive field work, required to implement an Expedited Response Action (ERA) for removing carbon tetrachloride contamination in the unsaturated soils in the 200 West Area of the Hanford Site. The request was based on concerns that the carbon tetrachloride residing in the soils was continuing to spread to the groundwater and, if left unchecked, would significantly increase the area of groundwater contamination. The purpose of this ERA is to minimize carbon tetrachloride migration within the unsaturated zone beneath and,away from the carbon tetrachloride disposal sites in the 200 West Area.

  15. Factors influencing substitutive transformation of carbon tetrachloride by pseudomonas sp. strain KC

    SciTech Connect

    Lewis, T.A.; Crawford, R.L.

    1995-12-31

    Pseudomonas sp. strain KC can transform carbon tetrachloride (CT) to carbon dioxide by an as yet unknown mechanism. In addition to CO{sub 2}, a large portion of the CT carbon atoms are found as unidentified non-volatile products. In order to assess the potential usefulness of this process as a remediation technology and to assure that other toxic compounds are not produced, experiments to investigate the transformation process were undertaken. Using L-cysteine or N,N-dimethylethylenediamine (DMED), the corresponding phosgene and thiophosgene condensation products from CT-transforming cultures of KC were observed, indicating that a radical substitution pathway was operating. Using radioisotopic tracer, it was found that the addition of DMED caused a substantial decrease in CO{sub 2} production. Other experiments were undertaken to account for the fraction of CT transformation accounted for by the sulfur and oxygen substitutive pathways. Data support a radical substitution pathway for the transformation of CT to CO{sub 2} and nonvolatile products. Furthermore, data suggest that the products of CT transformation would be fully dechlorinated due to the lability of the carbon-chlorine bonds in phosgene and thiophosgene.

  16. Microsomal lipid peroxidation. II. Stimulation by carbon tetrachloride

    SciTech Connect

    Kornbrust, D.J.; Mavis, R.D.

    1980-01-01

    Carbon tetrachloride initiated lipid peroxidation in isolated rat liver microsomes in the absence of free metal ions. In contrast to the nonenzymatic process stimulated by ferrous iron, CCl/sub 4/-induced peroxidation showed an absolute requirement for NADPH and appeared dependent on the integrity of cytochrome. No detectable peroxidation was induced by CCl/sub 4/ in microsomes from brain, kidney, or lung, and microsomal aminopyrine demethylase and aniline hydroxylase activities were more than 10-fold lower in these tissues compared to liver. These results are consistent with activation of CCl/sub 4/ by cytochrome P-450 to a reactive short lived radical which initiated peroxidation in the immediate vicinity of the cytochrome and thereby initiates peroxidation in the immediate vicinity of the cytochrome and thereby inhibits enzyme activity either by destruction of essential lipids or by direct attack on the enzyme by reactive intermediates of the peroxidative process. Loss of cytochrome P-450 activity then results in cessation of the CCl/sub 4/-induced peroxidative response prior to more extensive reaction of membrane polyunsaturated lipids.

  17. Reductive dehalogenation of carbon tetrachloride by Escherichia coli K-12.

    PubMed Central

    Criddle, C S; DeWitt, J T; McCarty, P L

    1990-01-01

    The formation of radicals from carbon tetrachloride (CT) is often invoked to explain the product distribution resulting from its transformation. Radicals formed by reduction of CT presumably react with constituents of the surrounding milieu to give the observed product distribution. The patterns of transformation observed in this work were consistent with such a hypothesis. In cultures of Escherichia coli K-12, the pathways and rates of CT transformation were dependent on the electron acceptor condition of the media. Use of oxygen and nitrate as electron acceptors generally prevented CT metabolism. At low oxygen levels (approximately 1%), however, transformation of [14C]CT to 14CO2 and attachment to cell material did occur, in accord with reports of CT fate in mammalian cell cultures. Under fumarate-respiring conditions, [14C]CT was recovered as 14CO2, chloroform, and a nonvolatile fraction. In contrast, fermenting conditions resulted in more chloroform, more cell-bound 14C, and almost no 14CO2. Rates of transformation of CT were faster under fermenting conditions than under fumarate-respiring conditions. Transformation rates also decreased over time, suggesting the gradual exhaustion of transformation activity. This loss was modeled with a simple exponential decay term. PMID:2268147

  18. Removal of Carbon Tetrachloride from a Layered Porous Medium by Means of Soil Vapor Extraction Enhanced by Desiccation and Water Table Reduction

    SciTech Connect

    Oostrom, Mart; Dane, Jacob H.; Wietsma, Thomas W.

    2005-11-14

    A two-dimensional flow cell experiment was conducted to study the removal of the carbon tetrachloride component of a DNAPL mixture from a layered porous medium through soil vapor extraction (SVE) with moist and dry air. A dual-energy gamma radiation system was used at various times to non-intrusively determine fluid saturations. The mixture, which contained the volatile organic carbon tetrachloride, mimics the DNAPL disposed at the Hanford Site in Washington State. The flow cell, which is 100 cm long, 75 cm high and 5.5 cm wide, was packed with two sloped coarse sand and two sloped silt layers in an otherwise uniform matrix of medium-grained sand. A V-shaped fine sand layer was placed at the bottom of the flow cell to prevent DNAPL from exiting the flow cell. The water table was located 2 cm from the bottom, creating variably saturated conditions. A 500-mL spill was introduced at the top of the flow cell from a small source area. It was observed that the DNAPL largely by-passed the silt layers but easily moved into the coarse sand layers. Residual DNAPL was formed in the medium-grained sand matrix. The DNAPL caused a distinct reduction of the capillary fringe. Most of the DNAPL ended up in a pool on top of the V-shaped fine sand. Through four treatments with moist air soil vapor extraction, most residual carbon tetrachloride was removed from the medium-grained matrix and the coarse sand layers. However, soil vapor extraction with moist air was not able to remove the carbon tetrachloride from the silt layers and the pool. Through a water table reduction and subsequent soil vapor extraction with dry air, the carbon tetrachloride in the silt layers and the pool was effectively removed. Based on gamma measurements and carbon tetrachloride vapor concentration data, it was estimated that after the final remediation treatment, almost 90% of the total mass was removed.

  19. Mesoscale Tank Experiments for Investigating Carbon Tetrachloride Biodegradation

    SciTech Connect

    Brady D. Lee; Robert J. Lenhard

    2005-06-01

    Mesoscale tank experiments were performed to simulate bioremediation of saturated zone carbon tetrachloride (CCl4) originating from a vadose zone carbon tetrachloride source. The mesoscale tank is 2-m wide by 2-m high by 3-m long and was constructed of stainless steel, yielding a total volume of 12 m3. Simulated geology within the tank consisted of two unconsolidated sand layers separated by a clay layer containing variable-sized stainless steel tubes that represented fractures within a consolidated porous medium. The thickness of the upper sand layer was approximately 55 cm, the thickness of the virtual fracture layer was 25 cm, and the thickness of the lower sand layer was approximately 98 cm. The water table was located at an elevation of approximately 54 cm from the bottom of the tank. CCl4 was added to the sealed tank by pouring 500 ml of neat CCl4 into a beaker buried approximately 10 cm below the upper sand surface through a stainless steel tube. The CCl4 was then allowed to partition through the reactor over time, eventually coming to equilibrium. Once CCl4 equilibrium had occurred in the saturated zone (~500 ppb); the reactor was bioaugmented with a CCl4 degrading culture enriched from the Subsurface Disposal Area at the INEEL. The culture was grown to a cell density of ~ 1.0 x 108 cells/ml and injected into the simulated aquifer through a center sampling port. Following injection of the culture, an initial aliquot of lactate (1,000 g/L), nitrogen, and phosphorus were added to the reactor. Lactate was injected every 3 – 5 days for one month. After 1 month of operation, a continuous supply of lactate (1,000 g/L) was pumped into the reactor at an average rate of 50 mL/min. CCl4 concentrations in the unsaturated zone were measured using hollow fiber membrane samplers, while liquid samples were analyzed to monitor levels in the simulated aquifer zone. Samples were also taken for analysis of volatile organic acids and cell density. As would be expected

  20. Investigation of carbon tetrachloride destruction by copper acetate.

    PubMed

    Chien, Yi-Chi

    2012-01-01

    Halogenated synthetic organic compounds are used in a wide variety of pesticides, solvents, refrigerants, fire retardants, and paints that cause extensive pollution to the air, surface water, groundwater, and soils. Carbon tetrachloride (CCl) is a typical halogenated synthetic organic compound that has been suspected to be toxic and carcinogenic and to cause ozone depletion. In the present work, molecular-level destruction of CCl by copper acetate was investigated by extended X-ray absorption fine structural spectra, X-ray absorption near-edge spectra, X-ray photoelectron spectroscopy, and X-ray diffraction spectroscopy. Experimentally, the Cl species dissociated from CCl were abstracted by copper species and formed CuCl. At 473 to 533 K, reaction products (copper chloride) aggregated on the surfaces of CuO, which might cause the obstruction of further CCl destruction. Due to the insertion of Cl species into the matrix of CuO, the bond distances of Cu-O and Cu-(O)-Cu were increased by 0.3 to 0.4 Å and 0.3 to 0.6 Å, respectively. However, at 603 K, because 79.5% of the Cu was in the CCl destruction solid products, the coordination number of Cu-(O)-Cu increased to 5.6. Molecular level investigations are a key to identifying the mechanisms of the CCl destruction process. In addition, identification of the molecular characteristics of the products may help in safe disposal of the toxic substances. The success of this study paved the way for the destruction of halogenated organic compounds by copper acetate. PMID:22370408

  1. Improved ACE-FTS observations of carbon tetrachloride (CCl4)

    NASA Astrophysics Data System (ADS)

    Harrison, Jeremy; Chipperfield, Martyn; Boone, Chris; Bernath, Peter

    2016-04-01

    The Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS), on board the SCISAT satellite, has been recording solar occultation spectra through the Earth's atmosphere since 2004 and continues to take measurements with only minor loss in performance. ACE-FTS time series are available for a range of chlorine 'source' gases, including CCl3F (CFC-11), CCl2F2 (CFC-12), CHF2Cl (HCFC-22), CH3Cl and CCl4. Recently there has been much community interest in carbon tetrachloride (CCl4), a substance regulated by the Montreal Protocol because it leads to the catalytic destruction of stratospheric ozone. Estimated sources and sinks of CCl4 remain inconsistent with observations of its abundance. Satellite observations of CCl4 in the stratosphere are particularly useful in validating stratospheric loss (photolysis) rates; in fact the atmospheric loss of CCl4 is essentially all due to photolysis in the stratosphere. However, the latest ACE-FTS v3.5 CCl4 retrieval is biased high by ˜ 20-30%. A new ACE-FTS retrieval scheme utilising new laboratory spectroscopic measurements of CCl4 and improved microwindow selection has recently been developed. This improves upon the v3.5 retrieval and resolves the issue of the high bias; this new scheme will form the basis for the upcoming v4 processing version of ACE-FTS data. This presentation will outline the improvements made in the retrieval, and a subset of data will be compared with modelled CCl4 distributions from SLIMCAT, a state-of-the-art three-dimensional chemical transport model. The use of ACE-FTS data to evaluate the modelled stratospheric loss rate of CCl4 will also be discussed. The evaluated model, which also includes a treatment of surface soil and ocean sinks, will then be used to quantify current uncertainties in the global budget of CCl4.

  2. Mechanisms of circadian rhythmicity of carbon tetrachloride hepatotoxicity.

    PubMed

    Bruckner, James V; Ramanathan, Raghupathy; Lee, K Monica; Muralidhara, Srinivasa

    2002-01-01

    The toxicity of carbon tetrachloride (CCl(4)) and certain other chemicals varies over a 24-h period. Because the metabolism of some drugs follows a diurnal rhythm, it was decided to investigate whether the hepatic metabolic activation of CCl(4) was rhythmic and coincided in time with maximum susceptibility to CCl(4) hepatotoxicity. A related objective was to test the hypothesis that abstinence from food during the sleep cycle results in lipolysis and formation of acetone, which participates in induction of liver microsomal cytochrome P450IIE1 (CYP2E1), resulting in a diurnal increase in CCl(4) metabolic activation and acute liver injury. Groups of fed and fasted male Sprague-Dawley rats were given a single oral dose of 800 mg of CCl(4)/kg at 2- to 4-h intervals over a 24-h period. Serum enzyme activities, measured 24 h post dosing as indices of acute liver injury, exhibited distinct maxima in both fed and fasted animals dosed with CCl(4) near the beginning of their dark/active cycle. Blood acetone, hepatic CYP2E1 activity, and covalent binding of (14)CCl(4)/metabolites to hepatic microsomal proteins in untreated rats fed ad libitum followed circadian rhythms similar to that of susceptibility to CCl(4). Parallel fluctuations of greater amplitude were seen in rats fasted for 24 h. Hepatic glutathione levels were lowest at the time of greatest susceptibility to CCl(4). Acetone dose-response experiments showed high correlations between blood acetone levels, CYP2E1 induction, and CCl(4)-induced liver injury. Pretreatment with diallyl sulfide suppressed CYP2E1 and abolished the circadian rhythmicity of susceptibility to CCl(4). These findings provide additional support for acetone's physiological role in CYP2E1 induction and for CYP2E1's role in modulating CCl(4) chronotoxicity in rats. PMID:11752126

  3. Microbial Removal of Atmospheric Carbon Tetrachloride in Bulk Aerobic Soils▿

    PubMed Central

    Mendoza, Y.; Goodwin, K. D.; Happell, J. D.

    2011-01-01

    Atmospheric concentrations of carbon tetrachloride (CCl4) were removed by bulk aerobic soils from tropical, subtropical, and boreal environments. Removal was observed in all tested soil types, indicating that the process was widespread. The flux measured in field chamber experiments was 0.24 ± 0.10 nmol CCl4 (m2 day)−1 (average ± standard deviation [SD]; n = 282). Removal of CCl4 and removal of methane (CH4) were compared to explore whether the two processes were linked. Removal of both gases was halted in laboratory samples that were autoclaved, dry heated, or incubated in the presence of mercuric chloride (HgCl2). In marl soils, treatment with antibiotics such as tetracycline and streptomycin caused partial inhibition of CCl4 (50%) and CH4 (76%) removal, but removal was not affected in soils treated with nystatin or myxothiazol. These data indicated that bacteria contributed to the soil removal of CCl4 and that microeukaryotes may not have played a significant role. Amendments of methanol, acetate, and succinate to soil samples enhanced CCl4 removal by 59%, 293%, and 72%, respectively. Additions of a variety of inhibitors and substrates indicated that nitrification, methanogenesis, or biological reduction of nitrate, nitrous oxide, or sulfate (e.g., occurring in possible anoxic microzones) did not play a significant role in the removal of CCl4. Methyl fluoride inhibited removal of CH4 but not CCl4, indicating that CH4 and CCl4 removals were not directly linked. Furthermore, CCl4 removal was not affected in soils amended with copper sulfate or methane, supporting the results with MeF and suggesting that the observed CCl4 removal was not significantly mediated by methanotrophs. PMID:21724884

  4. Microbial removal of atmospheric carbon tetrachloride in bulk aerobic soils.

    PubMed

    Mendoza, Y; Goodwin, K D; Happell, J D

    2011-09-01

    Atmospheric concentrations of carbon tetrachloride (CCl(4)) were removed by bulk aerobic soils from tropical, subtropical, and boreal environments. Removal was observed in all tested soil types, indicating that the process was widespread. The flux measured in field chamber experiments was 0.24 ± 0.10 nmol CCl(4) (m(2) day)(-1) (average ± standard deviation [SD]; n = 282). Removal of CCl(4) and removal of methane (CH(4)) were compared to explore whether the two processes were linked. Removal of both gases was halted in laboratory samples that were autoclaved, dry heated, or incubated in the presence of mercuric chloride (HgCl(2)). In marl soils, treatment with antibiotics such as tetracycline and streptomycin caused partial inhibition of CCl(4) (50%) and CH(4) (76%) removal, but removal was not affected in soils treated with nystatin or myxothiazol. These data indicated that bacteria contributed to the soil removal of CCl(4) and that microeukaryotes may not have played a significant role. Amendments of methanol, acetate, and succinate to soil samples enhanced CCl(4) removal by 59%, 293%, and 72%, respectively. Additions of a variety of inhibitors and substrates indicated that nitrification, methanogenesis, or biological reduction of nitrate, nitrous oxide, or sulfate (e.g., occurring in possible anoxic microzones) did not play a significant role in the removal of CCl(4). Methyl fluoride inhibited removal of CH(4) but not CCl(4), indicating that CH(4) and CCl(4) removals were not directly linked. Furthermore, CCl(4) removal was not affected in soils amended with copper sulfate or methane, supporting the results with MeF and suggesting that the observed CCl(4) removal was not significantly mediated by methanotrophs.

  5. Hepatoprotective Efficacy of Cichorium intybus L. Extract Against Carbon Tetrachloride-induced Liver Damage in Rats.

    PubMed

    Elgengaihi, Souad; Mossa, Abdel-Tawab H; Refaie, Amel A; Aboubaker, Doha

    2016-01-01

    The purpose of the study was to assess the phytochemical and hepatoprotective activity of different extracts of dried herb of Cichorium intybus L. against carbon tetrachloride (CCl4) intoxicated male albino rats. The hepatoprotective activity of different extracts at 500 mg/kg body weight was compared with carbon tetrachloride-treated animals. The animals were divided into five groups with six animals in each group. The first group represents control, the second group received carbon tetrachloride, the third received C. intybus, and the fourth group received C. intybus plus carbon tetrachloride. The fifth group received silymarin as hepato-slandered drug. There were significant changes in serum biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, albumin, total protein, and γ-glutamyl transferase (GGT) in carbon tetrachloride intoxicated rats, which were restored towards normal values in C. intybus-treated animals. Histopathological examination of liver tissues further substantiated these findings. In conclusion, of this investigation, the results ascertain that the herb extracts of C. intybus possess significant hepatoprotective activity. PMID:26913368

  6. Effect of the aqueous extract of Syzygium cumini on carbon tetrachloride-induced hepatotoxicity in rats.

    PubMed

    Moresco, Rafael Noal; Sperotto, Rita Leal; Bernardi, Anie Schiavo; Cardoso, Ricardo França; Gomes, Patrícia

    2007-08-01

    The aim of this study was to evaluate the effect of the aqueous Syzygium cumini leaf extract, given either as a single dose or by 7 days of pretreatment, on hepatotoxicity induced by carbon tetrachloride in rats. Blood samples obtained after treatments were measured for aspartate aminotransferase (AST) and alanine aminotransferase (ALT). A significant increase in the AST and ALT activities occurred after carbon tetrachloride administration alone, which was significantly lowered by preadministration with the aqueous extract of Syzygium cumini, but not by a single dose. This suggests that the extract may be useful for liver protection but needs to be given over a significant period and prior to liver injury. PMID:17450508

  7. Abiotic degradation rates for carbon tetrachloride and chloroform: Final report.

    SciTech Connect

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Humphrys, Daniel R.; Wietsma, Thomas W.; Truex, Michael J.

    2012-12-01

    This report documents the objectives, technical approach, and progress made through FY 2012 on a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater for carbon tetrachloride (CT) and chloroform (CF). The project also sought to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. We conducted 114 hydrolysis rate experiments in sealed vessels across a temperature range of 20-93 °C for periods as long as 6 years, and used the Arrhenius equation to estimate activation energies and calculate half-lives for typical Hanford groundwater conditions (temperature of 16 °C and pH of 7.75). We calculated a half-life of 630 years for hydrolysis for CT under these conditions and found that CT hydrolysis was unaffected by contact with sterilized, oxidized minerals or Hanford sediment within the sensitivity of our experiments. In contrast to CT, hydrolysis of CF was generally slower and very sensitive to pH due to the presence of both neutral and base-catalyzed hydrolysis pathways. We calculated a half-life of 3400 years for hydrolysis of CF in homogeneous solution at 16 °C and pH 7.75. Experiments in suspensions of Hanford sediment or smectite, the dominant clay mineral in Hanford sediment, equilibrated to an initial pH of 7.2, yielded calculated half-lives of 1700 years and 190 years, respectively, at 16 °C. Experiments with three other mineral phases at the same pH (muscovite mica, albite feldspar, and kaolinite) showed no change from the homogeneous solution results (i.e., a half-life of 3400 years). The strong influence of Hanford sediment on CF hydrolysis was attributed to the presence of smectite and its ability to adsorb protons, thereby buffering the solution pH at a higher level than would otherwise occur. The project also determined liquid-vapor partition coefficients for CT under the temperatures and pressures encountered in the sealed vessels that

  8. Potentiation of carbon tetrachloride hepatotoxicity by pentosan polysulfate in rats.

    PubMed

    Zim, M C A; Silveira, T R; Schwartsmann, G; Cerski, T; Motta, A

    2002-11-01

    Few data are available in the literature regarding the effect of pentosan polysulfate (PPS) on normal and fibrotic rat livers. In addition, the combination of PPS and carbon tetrachloride (CCl4) has not been studied so far. The objective of this study was to assess the effect of PPS on rat livers treated or not with CCl4 for the induction of liver fibrosis. The study consisted of four stages: 1) hepatic fibrosis induction with CCl4 (N = 36 rats); 2) evaluation of the effect of PPS on CCl4-induced hepatic fibrosis (N = 36 rats); 3) evaluation of the effect of higher doses of PPS in combination with CCl4 (N = 50 rats); 4) evaluation of the presence of an enzymatic inductor effect by PPS (N = 18 rats) using the sodium pentobarbital test which indirectly evaluates hepatic microsomal enzyme activity in vivo. Adult (60 to 70 days) male Wistar rats weighing 180 to 220 g were used. All animals receiving 0.5 ml 8% CCl4 (N = 36) developed hepatic fibrosis, and after 8 weeks they also developed cirrhosis. No delay or prevention of hepatic fibrosis was observed with the administration of 5 mg/kg PPS (N = 8) and 1 mg/kg PPS (N = 8) 1 h after the administration of CCl4, but the increased hepatotoxicity resulting from the combination of the two substances caused massive hepatic necrosis in most rats (N = 45). PPS (40 mg/kg) alone caused hepatic congestion only after 8 weeks, but massive hepatic necrosis was again observed in association with 0.5 ml CCl4 after 1 to 4 weeks of treatment. Unexpectedly, sleeping time increased with time of PPS administration (1, 2, or 3 weeks). This suggests that PPS does not function as an activator of the hepatic microsomal enzymatic system. Further studies are necessary in order to clarify the unexpected increase in hepatotoxicity caused by the combination of CCl4 and high doses of PPS, which results in massive hepatic necrosis.

  9. A biochemical and immunohistochemical study of the protective effects of carnosine for carbon tetrachloride induced liver injury in rats.

    PubMed

    Kuloglu, N; Sönmez, M F

    2015-01-01

    We investigated the protective effect of carnosine on carbon tetrachloride-induced liver tissue damage. Thirty-two adult male rats were divided into four equal groups. Group 1 was the untreated control, group 2 was injected with 0.2 ml/kg/day carbon tetrachloride, group 3 was injected with with 0.2 ml/kg/day carbon tetrachloride plus 200 mg/kg/day carnosine, and group 4 was injected with 200 mg/kg/day carnosine. Increased serum alanine amino transferase and aspartate amino transferase levels, liver malondialdehyde levels, HSP-70 expression and steatosis were observed following treatment with carbon tetrachloride. Carbon tetrachloride caused severe biochemical and histopathological changes in liver tissue and treatment with carnosine partially prevented the damage. HSP-70 may help control liver damage. PMID:25978138

  10. Update on the aquifer/wetlands restoration project at Utica, Nebraska, with recommendations for remapping of the carbon tetrachloride contamination in groundwater.

    SciTech Connect

    LaFreniere, L. M.; Environmental Science Division

    2010-04-20

    develop this treatment approach, additional groundwater sampling was conducted to update the distribution of carbon tetrachloride in groundwater identified in the preliminary studies in 1992-1993. In March 1998, detailed mapping of the carbon tetrachloride plume was performed by using the Argonne cone penetrometer (CPT) vehicle to collect groundwater samples for analyses for volatile organic compounds (VOCs) at 13 locations (PS01-PS09, PS12, PS16, PS17, PS19; Figure 1.2). The samples were collected in vertical profiles through the aquifer, at 10-ft intervals. The results of this 1998 study (Table 1.2) demonstrated that the three-dimensional distribution of carbon tetrachloride in the aquifer is complex, with multiple 'hot spots' occurring in the plume at various depths and distances along its length (Argonne 2000). In October 2002, the CCC/USDA requested that Argonne perform targeted groundwater sampling at Utica to document the migration of the carbon tetrachloride plume since the 1998 sampling event. In February 2003, vertical-profile groundwater sampling for VOCs analyses was conducted at 8 selected locations (PS01, PS04-PS07, PS12, PS19, PS20; Figure 1.2 and Table 1.3). The lateral and vertical configuration of the carbon tetrachloride plume, as identified in the 2003 study (Argonne 2003), is illustrated in Figures 1.3-1.7. On the basis of the 2003 groundwater sampling results, a remedial system employing four extraction wells (GWEX 1-GWEX 4), with groundwater treatment by spray irrigation and conventional air stripping, was implemented at Utica, with the concurrence of the CCC/USDA and the agencies identified in Table 1.1. The principal components of the Utica system (shown in Figure 1.8) are described briefly in Section 1.2. Operation of well GWEX4 and the associated air stripper began on October 29, 2004, and routine operation of wells GWEX1-GWEX3 and the spray irrigation treatment units began on November 22, 2004.

  11. Effects of silymarin on the resolution of liver fibrosis induced by carbon tetrachloride in rats.

    PubMed

    Tsai, J H; Liu, J Y; Wu, T T; Ho, P C; Huang, C Y; Shyu, J C; Hsieh, Y S; Tsai, C C; Liu, Y C

    2008-07-01

    Silymarin, a standardized extract of the milk thistle (Silybum marianum), has a long tradition as a herbal remedy, and was introduced as a hepatoprotective agent a few years ago. However, the therapeutic effects of silymarin remain undefined. Carbon tetrachloride (CCl4) is a xenobiotic used extensively to induce oxidative stress and is one of the most widely used hepatic toxins for experimental induction of liver fibrosis in the laboratory. In this study, we investigated the restoration of the CCl4-induced hepatic fibrosis by high dose of silymarin in rats. After treatment with oil (as normal group; n = 6) or CCl4 [as model (n = 7) and therapeutic (n = 7) groups] by intragastric delivery for 8 weeks for the induction of liver fibrosis, the rats in the normal and model group were administered orally normal saline four times a week for 3 weeks whilst the therapeutic group received silymarin (200 mg/kg). The histopathological changes were observed with Masson staining. The results showed that the restoration of the CCl4-induced damage of liver fibrosis in the therapeutic group was significantly increased as compared to that in the model group. Moreover, silymarin significantly decreased the elevation of aspartate aminotransferase (AST), alanine aminotransferase, and alkaline phosphatase in serum, and also reversed the altered expressions of alpha-smooth muscle actin in liver tissue. Therefore, these findings indicated that silymarin may have the potential to increase the resolution of the CCl4-induced liver fibrosis in rats.

  12. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties - Final Report

    SciTech Connect

    Mallouk, Thomas E.

    2000-09-01

    This research is a three year project involving close collaboration between chemists at Pennsylvania State University and materials scientists at Pacific Northwest National Laboratory (PNNL). The goal of the project is the development and characterization of supported reducing agents, and solid waste forms derived from them, which will be effective in remediation of aqueous wastes. The work follows the recent discovery that zero-valent metals, such as iron, are effective decontaminants for waste streams containing chlorinated hydrocarbons. Preliminary data, obtained at Penn State and elsewhere, have shown that the same strategy will be effective in reducing soluble compounds containing toxic metals (technetium, lead, mercury, and chromium) to insoluble forms. The Penn State group has prepared a new class of powerful reducing agents, called Ferragels, which consist of finely divided zero-valent metals on high surface area supports. Because the rate of the surface oxidation-reduction reaction depends on available surface area, Ferragels are more effective in every case tested to date than unsupported metals. The project will further develop and investigate the application of these composite materials to problems relevant to the DOE-EM mission, namely the detoxification of waste streams containing technetium, carbon tetrachloride, and toxic metal ions. The Penn State group will work closely with the PNNL group to prepare materials that are compatible with the highly corrosive liquid fraction of Hanford site tank waste, to conduct tests with waste simulants containing technetium, and to formulate and characterize vitrified waste forms derived from these materials.

  13. Degradation of carbon tetrachloride in aqueous solution in the thermally activated persulfate system.

    PubMed

    Xu, Minhui; Gu, Xiaogang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Miao, Zhouwei; Zang, Xueke; Wu, Xiaoliang

    2015-04-01

    Thermal activation of persulfate (PS) has been identified to be effective in the destruction of organic pollutants. The feasibility of carbon tetrachloride (CT) degradation in the thermally activated PS system was evaluated. The experimental results showed that CT could be readily degraded at 50 °C with a PS concentration of 0.5M, and CT degradation and PS consumption followed the pseudo-first order kinetic model. Superoxide radical anion (O2(*-)) was the predominant radical species responsible for CT degradation and the split of CCl was proposed as the possible reaction pathways for CT degradation. The process of CT degradation was accelerated by higher PS dose and lower initial CT concentration. No obvious effect of the initial pH on the degradation of CT was observed in the thermally activated PS system. Cl(*-), HCO3(*-), and humic acid (HA) had negative effects on CT degradation. In addition, the degradation of CT in the thermally activated PS system could be significantly promoted by the solvents addition to the solution. In conclusion, the thermally activated PS process is a promising option in in-situ chemical oxidation/reduction remediation for degrading highly oxidized organic contaminants such as CT that is widely detected in contaminated sites.

  14. Removal of carbon tetrachloride from a layered porous medium by means of soil vapor extraction enhanced by desiccation and water table reduction

    SciTech Connect

    Oostrom, Mart; Dane, J H.; Wietsma, Thomas W.

    2005-11-16

    A two-dimensional flow cell experiment was conducted to study the removal of the carbon tetrachloride component of a DNAPL mixture from a layered porous medium through soil vapor extraction (SVE) with moist and dry air. A dual-energy gamma radiation system was used at various times to non-intrusively determine fluid saturations. The mixture, which contained the volatile organic carbon tetrachloride, mimics the DNAPL disposed at the Hanford Site in Washington State. The flow cell, which is 100 cm long, 75 cm high and 5.5 cm wide, was packed with two sloped coarse sand and two sloped silt layers in an otherwise uniform matrix of medium-grained sand. A V-shaped fine sand layer was placed at the bottom of the flow cell to prevent DNAPL from exiting the flow cell. The water table was located 2 cm from the bottom, creating variably saturated conditions. A 500-mL spill was introduced at the top of the flow cell from a small source area. It was observed that the DNAPL largely by-passed the silt layers but easily moved into the coarse sand layers. Residual DNAPL was formed in the medium-grained sand matrix. The DNAPL caused a distinct reduction of the capillary fringe. Most of the DNAPL ended up in a pool on top of the V-shaped fine sand. Through four treatments with moist air soil vapor extraction, most residual carbon tetrachloride was removed from the medium-grained matrix and the coarse sand layers. However, soil vapor extraction with moist air was not able to remove the carbon tetrachloride from the silt layers and the pool. Through a water table reduction and subsequent soil vapor extraction with dry air, the carbon tetrachloride in the silt layers and the pool was effectively removed. Based on gamma measurements and carbon tetrachloride vapor concentration data, it was estimated that after the final remediation treatment, almost 90% of the total mass was removed. Key Words: DNAPL; soil vapor extraction; desiccation; remediation

  15. REDUCTIVE DEHALOGENATION OF HEXACHLOROETHANE, CARBON TETRACHLORIDE, AND BROMOFORM BY ANTHRAHYDROQUINONE DISULFONATE AND HUMIC ACID

    EPA Science Inventory

    The reductive dehalogenation of hexachloroethane (CzCLj), carbon tetrachloride (CC14), and bromoform (CHBr3) was examined at 50 “C in aqueous solutions containing ei- ther (1) 500 pM of 2,6-anthrahydroquinone disulfonate (AHQDS), (2) 250 pM Fe2+, or (3) 250 pM HS-. The pH ranged ...

  16. TRANSFORMATION OF CARBON TETRACHLORIDE IN THE PRESENCE OF SULFIDE, BIOTITE, AND VERMICULITE

    EPA Science Inventory

    Carbon tetrachloride is transformed in aqueous solutions containing dissolved hydrogen sulfide more rapidly in the presence of the minerals biotite and vermiculite than in homogeneous systems. Approximately 8045% of the CC4 was transformed to COP via the measured intermediate, CS...

  17. Feasibility of Metabolic Parameter Estimation in Pharmacokinetic Models of Carbon Tetrachloride Exposure in Rats

    EPA Science Inventory

    Carbon tetrachloride (CCl4) is a toxic chemical that was once used in degreasers and detergents, and some remnants of the chemical may be present in the water supply. Physiologically based pharmacokinetic (PBPK) modeling can assist in understanding resulting internal d...

  18. Multivariate Curve Resolution Methods Illustrated Using Infrared Spectra of an Alcohol Dissolved in Carbon Tetrachloride

    ERIC Educational Resources Information Center

    Grung, Bjorn; Nodland, Egil; Forland, Geir Martin

    2007-01-01

    The analysis of the infrared spectra of an alcohol dissolved in carbon tetrachloride gives a better understanding of the various multivariate curve resolution methods. The resulting concentration profile is found to be very useful for calculating the degree of association and equilibrium constants of different compounds.

  19. Summary of canister overheating incident at the Carbon Tetrachloride Expedited Response Action site

    SciTech Connect

    Driggers, S.A.

    1994-03-10

    The granular activated carbon (GAC)-filled canister that overheated was being used to adsorb carbon tetrachloride vapors drawn from a well near the 216-Z-9 Trench, a subsurface disposal site in the 200 West Area of the Hanford Site. The overheating incident resulted in a band of discolored paint on the exterior surface of the canister. Although there was no other known damage to equipment, no injuries to operating personnel, and no releases of hazardous materials, the incident is of concern because it was not anticipated. It also poses the possibility of release of carbon tetrachloride and other hazardous vapors if the incident were to recur. All soil vapor extraction system (VES) operations were halted until a better understanding of the cause of the incident could be determined and controls implemented to reduce the possibility of a recurrence. The focus of this report and the intent of all the activities associated with understanding the overheating incident has been to provide information that will allow safe restart of the VES operations, develop operational limits and controls to prevent recurrence of an overheating incident, and safely optimize recovery of carbon tetrachloride from the ground.

  20. Buckwheat Honey Attenuates Carbon Tetrachloride-Induced Liver and DNA Damage in Mice

    PubMed Central

    Cheng, Ni; Wu, Liming; Zheng, Jianbin; Cao, Wei

    2015-01-01

    Buckwheat honey, which is widely consumed in China, has a characteristic dark color. The objective of this study was to investigate the protective effects of buckwheat honey on liver and DNA damage induced by carbon tetrachloride in mice. The results revealed that buckwheat honey had high total phenolic content, and rutin, hesperetin, and p-coumaric acid were the main phenolic compounds present. Buckwheat honey possesses super DPPH radical scavenging activity and strong ferric reducing antioxidant power. Administration of buckwheat honey for 10 weeks significantly inhibited serum lipoprotein oxidation and increased serum oxygen radical absorbance capacity. Moreover, buckwheat honey significantly inhibited aspartate aminotransferase and alanine aminotransferase activities, which are enhanced by carbon tetrachloride. Hepatic malondialdehyde decreased and hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase) increased in the presence of buckwheat honey. In a comet assay, lymphocyte DNA damage induced by carbon tetrachloride was significantly inhibited by buckwheat honey. Therefore, buckwheat honey has a hepatoprotective effect and inhibits DNA damage, activities that are primarily attributable to its high antioxidant capacity. PMID:26508989

  1. Hepatoprotective Effect of Houttuynia cordata Thunb Extract against Carbon Tetrachloride-induced Hepatic Damage in Mice

    PubMed Central

    Kang, H.; Koppula, S.

    2014-01-01

    Houttuynia cordata Thunb (Saururaceae) is a traditional medicinal herb used to treat several disease symptoms. The present study was focused on the hepatoprotective effects of H. cordata ethyl acetate extract in experimental mice. Further the antioxidant potential of the extract was also evaluated to substantiate its hepatoprotective properties. Carbon tetrachloride-induced hepatic damage in mice was used to measure the serum biochemical parameters. Morphological changes in hepatocyte architecture were studied by haematoxylin and eosin staining. In vitro alkyl and hydroxyl free radical scavenging assays were performed to evaluate the antioxidant effect. Administration of H. cordata extract significantly reduced the elevated serum levels and regulated the altered levels of serum cholesterol in carbon tetrachloride-treated mice (P<0.05). The morphological changes in hepatocyte architecture were also reversed by H. cordata treatment. Further, the extract showed significant antioxidant actions by scavenging the alkyl and hydroxyl free radicals. The concentration of the extract necessary for 50% scavenging of alkyl and hydroxyl radicals was 15.5 and 410 μg/ml, respectively. H. cordata extract exhibited significant hepatoprotective property in carbon tetrachloride-induced hepatotoxicity in mice. The strong antioxidant activities possessed by the extract might be responsible for such actions. PMID:25284923

  2. Hepatoprotective Effect of Houttuynia cordata Thunb Extract against Carbon Tetrachloride-induced Hepatic Damage in Mice.

    PubMed

    Kang, H; Koppula, S

    2014-07-01

    Houttuynia cordata Thunb (Saururaceae) is a traditional medicinal herb used to treat several disease symptoms. The present study was focused on the hepatoprotective effects of H. cordata ethyl acetate extract in experimental mice. Further the antioxidant potential of the extract was also evaluated to substantiate its hepatoprotective properties. Carbon tetrachloride-induced hepatic damage in mice was used to measure the serum biochemical parameters. Morphological changes in hepatocyte architecture were studied by haematoxylin and eosin staining. In vitro alkyl and hydroxyl free radical scavenging assays were performed to evaluate the antioxidant effect. Administration of H. cordata extract significantly reduced the elevated serum levels and regulated the altered levels of serum cholesterol in carbon tetrachloride-treated mice (P<0.05). The morphological changes in hepatocyte architecture were also reversed by H. cordata treatment. Further, the extract showed significant antioxidant actions by scavenging the alkyl and hydroxyl free radicals. The concentration of the extract necessary for 50% scavenging of alkyl and hydroxyl radicals was 15.5 and 410 μg/ml, respectively. H. cordata extract exhibited significant hepatoprotective property in carbon tetrachloride-induced hepatotoxicity in mice. The strong antioxidant activities possessed by the extract might be responsible for such actions. PMID:25284923

  3. Maresin 1, a Proresolving Lipid Mediator, Mitigates Carbon Tetrachloride-Induced Liver Injury in Mice

    PubMed Central

    Li, Ruidong; Wang, Yaxin; Zhao, Ende; Wu, Ke; Li, Wei; Shi, Liang; Wang, Di; Xie, Gengchen; Yin, Yuping; Deng, Meizhou; Zhang, Peng; Tao, Kaixiong

    2016-01-01

    Maresin 1 (MaR 1) was recently reported to have protective properties in several different animal models of acute inflammation by inhibiting inflammatory response. However, its function in acute liver injury is still unknown. To address this question, we induced liver injury in BALB/c mice with intraperitoneal injection of carbon tetrachloride with or without treatment of MaR 1. Our data showed that MaR 1 attenuated hepatic injury, oxidative stress, and lipid peroxidation induced by carbon tetrachloride, as evidenced by increased thiobarbituric acid reactive substances and reactive oxygen species levels were inhibited by treatment of MaR 1. Furthermore, MaR 1 increased activities of antioxidative mediators in carbon tetrachloride-treated mice liver. MaR 1 decreased indices of inflammatory mediators such as tumor necrosis factor-α, interleukin-6, interleukin-1β, monocyte chemotactic protein 1, myeloperoxidase, cyclooxygenase-2, and inducible nitric oxide synthase. Administration of MaR 1 inhibited activation of nuclear factor kappa B (NF-κb) and mitogen-activated protein kinases (MAPKs) in the liver of CCl4 treated mice. In conclusion, these results suggested the antioxidative, anti-inflammatory properties of MaR 1 in CCl4 induced liver injury. The possible mechanism is partly implicated in its abilities to inhibit ROS generation and activation of NF-κb and MAPK pathway. PMID:26881046

  4. Induction of rat kidney gluconeogenesis during acute liver intoxication by carbon tetrachloride.

    PubMed Central

    Faus, M J; Lupiáñez, A; Vargas, A; Sánchez-Medina, F

    1978-01-01

    1. Glucose production from L-lactate was completely inhibited 24h after carbon tetrachloride treatment in liver from 48h-starved rats. The activities of phosphoenolpyruvate carboxykinase, fructose diphosphatase and glucose 6-phosphatase were decreased by this treatment in fed and starved rats, whereas lactate dehydrogenase activity was only decreased in fed animals. 2. The production of glucose by renal cortical slices from fed rats previously treated with carbon tetrachloride was enhanced when L-lactate, pyruvate and glutamine but not fructose were used as glucose precursors. Renal phosphoenolpyruvate carboxykinase activity was increased in this condition. 3. This increase was counteracted by cycloheximide or actinomycin D, suggesting that the effect was due to the synthesis de novo of the enzyme. 4. The pattern of hepatic gluconeogenic metabolites in treated animals was characterized by an increase in lactate, pyruvate, malate and citrate as well as a decrease in glucose 6-phosphate, suggesting an impairment of liver gluconeogenesis in vivo. 5. In contrast, the profile of renal metabolites suggested that gluconeogenesis was operative in the treated rats, as indicated by the marked increase in the content of phosphoenolpyruvate, 2-phosphoglycerate, 3-phosphoglycerate and glucose 6-phosphate. 6. It is postulated that renal gluconeogenesis could contribute to the maintenance of glycaemia in carbon tetrachloride-treated rats. PMID:708398

  5. Adsorption of Carbon Tetrachloride to Sediments from the UP-1 Operable Unit

    SciTech Connect

    Wellman, Dawn M.; Riley, Robert G.; Parker, Kent E.; Mitroshkov, Alexandre V.

    2006-09-01

    In 2004, Fluor Hanford, Inc. (FHI) drilled several groundwater wells within the 200-UP-1 operable unit to monitor plumes that have been the focus of past remediation activities. Thirteen cores taken from three wells (C4298, C4299, and C4300) were sent to Pacific Northwest National Laboratory for characterization and quantification of contaminant retardation. These cores were 4-inches in diameter by 6-inches in length and were taken from depths near the unconfined aquifer surface (water table) to locations approximately 150 to 180 ft below the water table. Prior to this work, no 200-UP-1 site-specific adsorption data (i.e., values of distribution coefficient [Kd ]) were available for the sediments or key contaminants present in the 200-UP-1 operable unit groundwater plume. Site-specific sorption data for carbon tetrachloride (CCl4) was obtained with the <2 mm size fractions of uncontaminated 200-UP-1 sediments taken from two of these boreholes (C4299 and C4300) and distribution coefficients determined. Each fraction exhibited bimodal CCl4 adsorption isotherms over the concentration range (15 – 2500 μg L-1) for total CCl4 in solution. Sorption of CCl4 was linear over the concentration ranges of 15 to 400 μg L-1 and 400 to 2500 μg L-1. The Kd values measured for the three 200-UP-1 sediments exhibited bimodal sorption with initial Kd values ranging from 0.0002 to 0.0005, and phase 2 values approximately 0.003 for all sediments. The measure Kd values are lower than the range calculated for CCl4 in a Hanford soil (0.016 to 0.83 L/Kg) containing an average organic carbon content of 0.2% (Truex et al., 2001). The best estimate value of Truex et al. (2001) is 0.06 L/Kg based on a 0.1% sediment organic carbon content. However, this estimate is based on an organic carbon content up to an order of magnitude greater than the organic carbon content of the sediments tested herein. Prolonged contact may increase

  6. Investigation of antioxidant and hepatoprotective activity of standardized Curcuma xanthorrhiza rhizome in carbon tetrachloride-induced hepatic damaged rats.

    PubMed

    Devaraj, Sutha; Ismail, Sabariah; Ramanathan, Surash; Yam, Mun Fei

    2014-01-01

    Curcuma xanthorrhiza (CX) has been used for centuries in traditional system of medicine to treat several diseases such as hepatitis, liver complaints, and diabetes. It has been consumed as food supplement and "jamu" as a remedy for hepatitis. Hence, CX was further explored for its potential as a functional food for liver related diseases. As such, initiative was taken to evaluate the antioxidant and hepatoprotective potential of CX rhizome. Antioxidant activity of the standardized CX fractions was determined using in vitro assays. Hepatoprotective assay was conducted against carbon tetrachloride- (CCl4-) induced hepatic damage in rats at doses of 125, 250, and 500 mg/kg of hexane fraction. Highest antioxidant activity was found in hexane fraction. In the case of hepatoprotective activity, CX hexane fraction showed significant improvement in terms of a biochemical liver function, antioxidative liver enzymes, and lipid peroxidation activity. Good recovery was observed in the treated hepatic tissues histologically. Hence, the results concluded that CX hexane fraction possessed prominent hepatoprotective activities which might be due to its in vitro antioxidant activity. These findings also support the use of CX as a functional food for hepatitis remedy in traditional medicinal system. PMID:25133223

  7. 1994 conceptual model of the carbon tetrachloride contamination in the 200 West Area at the Hanford Site

    SciTech Connect

    Rohay, V.J.

    1994-08-01

    Between 1955 and 1973, a total of 363,000 to 580,000 L (577,000 to kg) of liquid carbon tetrachloride, in mixtures with other organic and aqueous, actinide-bearing fluids, were discharged to the soil column at three disposal facilities -- the 216-Z-9 Trench, the 216-Z-lA TiTe Field, and the 216-Z-18 Crib -- in the 200 West Area at the Hanford Site. In the mid-1980`s, dissolved carbon tetrachloride was found in the uppermost aquifer beneath the disposal facilities, and in late 1990, the US Environmental Protection Agency and the Washington State Department of Ecology requested that the US Department of Energy proceed with planning and implementation of an expedited response action (ERA) to minimize additional carbon tetrachloride contamination of the groundwater. In February 1992, soil vapor extraction was initiated to remove carbon tetrachloride from the unsaturated zone beneath these disposal facilities. By May 1994, a total of 10,560 L (16,790 kg) of carbon tetrachloride had been removed, amounting to an estimated 2% of the discharged inventory. In the spring of 1991, the Volatile Organic Compounds -- Arid Integrated Demonstration (VOC-Arid ID) program selected the carbon tetrachloride-contaminated site for demonstration and deployment of new technologies for evaluation and cleanup of volatile organic compounds and associated contaminants in soils and groundwater at arid sites. Site investigations conducted in support of both the ERA and the VOC-Arid ID have been integrated because of their shared objective to refine the conceptual model of the site and to promote efficiency. Site characterization data collected in fiscal year 1993 have supported and led to refinement of the conceptual model of the carbon tetrachloride site.

  8. Bioavailability of andrographolide and protection against carbon tetrachloride-induced oxidative damage in rats

    SciTech Connect

    Chen, Haw-Wen; Huang, Chin-Shiu; Li, Chien-Chun; Lin, Ai-Hsuan; Huang, Yu-Ju; Wang, Tsu-Shing; Yao, Hsien-Tsung; Lii, Chong-Kuei

    2014-10-01

    Andrographolide, a bioactive diterpenoid, is identified in Andrographis paniculata. In this study, we investigated the pharmacokinetics and bioavailability of andrographolide in rats and studied whether andrographolide enhances antioxidant defense in a variety of tissues and protects against carbon tetrachloride-induced oxidative damage. After a single 50-mg/kg administration, the maximum plasma concentration of andrographolide was 1 μM which peaked at 30 min. The bioavailability of andrographolide was 1.19%. In a hepatoprotection study, rats were intragastrically dosed with 30 or 50 mg/kg andrographolide for 5 consecutive days. The results showed that andrographolide up-regulated glutamate cysteine ligase (GCL) catalytic and modifier subunits, superoxide dismutase (SOD)-1, heme oxygenase (HO)-1, and glutathione (GSH) S-transferase (GST) Ya/Yb protein and mRNA expression in the liver, heart, and kidneys. The activity of SOD, GST, and GSH reductase was also increased in rats dosed with andrographolide (p < 0.05). Immunoblot analysis and EMSA revealed that andrographolide increased nuclear Nrf2 contents and Nrf2 binding to DNA, respectively. After the 5-day andrographolide treatment, one group of animals was intraperitoneally injected with carbon tetrachloride (CCl{sub 4}) at day 6. Andrographolide pretreatment suppressed CCl{sub 4}-induced plasma aminotransferase activity and hepatic lipid peroxidation (p < 0.05). These results suggest that andrographolide is quickly absorbed in the intestinal tract in rats with a bioavailability of 1.19%. Andrographolide protects against chemical-induced oxidative damage by up-regulating the gene transcription and activity of antioxidant enzymes in various tissues. - Highlights: • The bioavailability of andrographolide is 1.19% in rats. • Plasma concentration reaches 1 μM after giving 50 mg/kg andrographolide. • Andrographolide up-regulates Nrf2-dependent antioxidant genes. • Andrographolide increases antioxidant defense

  9. Transformation of carbon tetrachloride by Pseudomonas sp. strain KC under denitrification conditions

    SciTech Connect

    Criddle, C.S.; DeWitt, J.T.; Grbic-Galic, D.; McCarty, P.L. )

    1990-11-01

    A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of {sup 14}C-labeled CT by Pseudomonas strain KC under denitrification conditions were {sup 14}CO{sub 2} and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging.

  10. Adsorption of alkenyl succinic anhydride from solutions in carbon tetrachloride on a fine magnetite surface

    NASA Astrophysics Data System (ADS)

    Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

    2016-06-01

    The adsorption of alkenyl succinic anhydride from a solution in carbon tetrachloride on a fine magnetite surface at a temperature of 298.15 K is studied using fine magnetite, which forms the basis of magnetic fluids, as the adsorbent. An adsorption isotherm is recorded and interpreted in terms of the theory of the volume filling of micropores (TVFM). Adsorption process parameters are calculated on the basis of the isotherm. It is shown that at low equilibrium concentrations, the experimental adsorption isotherm is linear in the TVFM equation coordinates.

  11. Carbon tetrachloride replacement compounds for organic vapor air-purifying respirator cartridge and activated carbon testing--a review.

    PubMed

    Moyer, E S; Smith, S J; Wood, G O

    2001-01-01

    This article reviews efforts by researchers and organizations around the world to identify chemicals as substitutes for carbon tetrachloride in measuring activated carbon activity (adsorption capacity) or organic vapor air-purifying respirator cartridge (or other packed carbon bed) breakthrough times. Such measurements usually are done to determine if a minimum performance standard is met. Different criteria have been established, supporting data developed and used, and conclusions reached. This article presents relevant published, unpublished, obscure, and recalculated data which the reader can use to make a choice of replacement chemical and testing conditions. No recommendations for a specific replacement chemical are endorsed or promoted in this review. PMID:11549144

  12. Reduction of hexachloroethane and carbon tetrachloride at surfaces of biotite, vermiculite, pyrite, and marcasite. Book chapter Apr 88-Apr 90

    SciTech Connect

    Kriegman-King, M.R.; Reinhard, M.

    1991-01-01

    Contamination of groundwater resources by halogenated compounds spurred the formation of a national program to clean up hazardous waste sites across the United States. Compounds such as carbon tetrachloride (CTET), chloroform (CF), and hexachloroethane (HCA) are a few of the chemicals which have been proposed to be 'characteristic' hazardous wastes to be included in the toxic contaminant leachate potential (TCLP) test. Consequently, chemical and biological transformation pathways are being studied to aid in understanding the fate of these contaminants in groundwater environments and to apply the processes occurring naturally in groundwater environments to remediation technologies. Environmental factors significantly affect the transformation rates and the pathways of halogenated aliphatic compounds. The authors have studied the transformation of tetrachloromethane (CTET), and hexachloroethane (HCA) in homogenous and heterogenous systems designed to simulate groundwater and sediment conditions. The laboratory studies were aimed at (1) identifying the sediment components which may act as reducing components and (2) quantifying the environmental factors which govern the transformation rates. Both model and natural systems were studied. Their data indicate that the humic acid fraction in combination with sulfide and Fe(2+) may promote transformation rates. Similarly, surfaces of sheet silicates, such as biotite and vermiculite, were found to promote degradation of CTET and perchloroethylene, respectively.

  13. Adsorption of carbon tetrachloride on graphitized thermal carbon black and in slit graphitic pores: five-site versus one-site potential models.

    PubMed

    Do, D D; Do, H D

    2006-05-18

    The performance of intermolecular potential models on the adsorption of carbon tetrachloride on graphitized thermal carbon black at various temperatures is investigated. This is made possible with the extensive experimental data of Machin and Ross(1), Avgul et al.,(2) and Pierce(3) that cover a wide range of temperatures. The description of all experimental data is only possible with the allowance for the surface mediation. If this were ignored, the grand canonical Monte Carlo (GCMC) simulation results would predict a two-dimensional (2D) transition even at high temperatures, while experimental data shows gradual change in adsorption density with pressure. In general, we find that the intermolecular interaction has to be reduced by 4% whenever particles are within the first layer close to the surface. We also find that this degree of surface mediation is independent of temperature. To understand the packing of carbon tetrachloride in slit pores, we compared the performance of the potential models that model carbon tetrachloride as either five interaction sites or one site. It was found that the five-site model performs better and describes the imperfect packing in small pores better. This is so because most of the strength of fluid-fluid interaction between two carbon tetrachloride molecules comes from the interactions among chlorine atoms. Methane, although having tetrahedral shape as carbon tetrachloride, can be effectively modeled as a pseudospherical particle because most of the interactions come from carbon-carbon interaction and hydrogen negligibly contributes to this. PMID:16686498

  14. BML-11, a lipoxin receptor agonist, protected carbon tetrachloride-induced hepatic fibrosis in rats.

    PubMed

    Zhou, Xiao-Yan; Yu, Zhong-Jian; Yan, Dan; Wang, Hong-Mei; Huang, Yong-Hong; Sha, Juan; Xu, Fang-Yun; Cai, Zhen-Yu; Min, Wei-Ping

    2013-10-01

    Inflammation plays an important role in the occurrence and development of fibrosis. Lipoxins (LXs) and BML-111 (lipoxin A4 agonist) have been approved for potent anti-inflammatory properties. Previously, we and others had showed LXs and BML-111 could protect acute hepatic injury, inhibit the growth and invasion of hepatic tumor. However, there are few reports dealing with their effects on hepatic fibrosis. To explore whether LXs and the analog could interrupt the process of hepatic fibrosis, the effects of BML-111 on tetrachloride-induced hepatic fibrosis were observed and the possible mechanism were discussed. Sprague-Dawley rats were induced liver fibrosis by carbon tetrachloride (CCl4) for 10 weeks with or without BML-111, and the histopathology and collagen content were employed to quantify hepatic necro-inflammation and fibrosis. Moreover, the expression levels of α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and platelet-derived growth factor (PDGF) were examined via Western blot or ELISA. Rats treated with BML-111 improved hepatic necro-inflammation and inhibited hepatic fibrosis in association with reduction of α-SMA expression and decreased collagen deposition. Furthermore, BML-111 could downregulate the expressions of TGF-β1 and PDGF significantly. BML-111 played a critical protective role in CCl4-induced hepatic fibrosis through inhibiting the levels of TGF-β1 and PDGF in rats.

  15. Degradation Kinetics of Carbon Tetrachloride by Sulfate Green Rust as Influenced by pH and Copper Ions

    EPA Science Inventory

    Chlorinated solvents such as trichloroethene (TCE, C2HCl3) and carbon tetrachloride (CT, CCl4) are priority groundwater contaminants at many EPA field sites. Green rust (GR) minerals are important corrosion products of zerovalent iron (Fe0) that has been used in permeable reactiv...

  16. Degradation Kinetics of Carbon Tetrachloride by Sulfate Green Rust as Influenced by pH and Copper Ions (Stillwater)

    EPA Science Inventory

    Chlorinated solvents such as trichloroethene (TCE, C2HCl3) and carbon tetrachloride (CT, CCl4) are priority groundwater contaminants at many EPA field sites. Green rust (GR) minerals are important corrosion products of zerovalent iron (Fe0) that has been used in permeable react...

  17. Stimulating natural defenses in poplar clones (OP-367) increases plant metabolism of carbon tetrachloride.

    PubMed

    Ferrieri, Abigail P; Thorpe, Michael R; Ferrieri, Richard A

    2006-01-01

    Groundwater contamination by carbon tetrachloride (CCl4) presents a health risk as a potential carcinogen and pollutant that is capable of depleting the ozone layer. Although use of poplar trees in a phytoremediation capacity has proven to be cost effective for cleaning contaminated sites, minimizing leaf emission of volatile contaminants remains a pressing issue. We hypothesized that recently fixed carbon plays a key role in CCl4 metabolism in planta yielding nonvolatile trichloroacetic acid (TCA) and that the extent of this metabolism can be altered by heightening plant defenses. Labeling intact leaves with (11)CO2 (t 1/2 20.4 m) can test this hypothesis, because the extremely short half-life of the tracer reflects only those processes involving recently fixed carbon. Using radio-HPLC analysis, we observed [(11)C]TCA from leaf extract from poplar clones (OP-367) whose roots were exposed to a saturated solution of CCl4 (520 ppm). Autoradiography of [(11)C]photosynthate showed increased leaf export and partitioning to the apex within 24 h of CCl4 exposure, suggesting that changes in plant metabolism and partitioning of recently fixed carbon occur rapidly. Additionally, leaf CCl4 emissions were highest in the morning, when carbon pools are low, suggesting a link between contaminant metabolism and leaf carbon utilization. Further, treatment with methyljasmonate, a plant hormone implicated in defense signal transduction, reduced leaf CCl4 emissions two-fold due to the increased formation of TCA.

  18. Stochastic estimates of exposure and cancer risk from carbon tetrachloride released to the air from the rocky flats plant.

    PubMed

    Rood, A S; McGavran, P D; Aanenson, J W; Till, J E

    2001-08-01

    Carbon tetrachloride is a degreasing agent that was used at the Rocky Flats Plant (RFP) in Colorado to clean product components and equipment. The chemical is considered a volatile organic compound and a probable human carcinogen. During the time the plant operated (1953-1989), most of the carbon tetrachloride was released to the atmosphere through building exhaust ducts. A smaller amount was released to the air via evaporation from open-air burn pits and ground-surface discharge points. Airborne releases from the plant were conservatively estimated to be equivalent to the amount of carbon tetrachloride consumed annually by the plant, which was estimated to be between 3.6 and 180 Mg per year. This assumption was supported by calculations that showed that most of the carbon tetrachloride discharged to the ground surface would subsequently be released to the atmosphere. Atmospheric transport of carbon tetrachloride from the plant to the surrounding community was estimated using a Gaussian Puff dispersion model (RATCHET). Time-integrated concentrations were estimated for nine hypothetical but realistic exposure scenarios that considered variation in lifestyle, location, age, and gender. Uncertainty distributions were developed for cancer slope factors and atmospheric dispersion factors. These uncertainties were propagated through to the final risk estimate using Monte Carlo techniques. The geometric mean risk estimates varied from 5.2 x 10(-6) for a hypothetical rancher or laborer working near the RFP to 3.4 x 10(-9) for an infant scenario. The distribution of incremental lifetime cancer incidence risk for the hypothetical rancher was between 1.3 x 10(-6) (5% value) and 2.1 x 10(-5) (95% value). These estimates are similar to or exceed estimated cancer risks posed by releases of radionuclides from the site. PMID:11726020

  19. Carbon Tetrachloride and Chloroform Attenuation Parameter Studies: Heterogeneous Hydrolytic Reactions -- Status Report

    SciTech Connect

    Amonette, James E.; Qafoku, Odeta; Wietsma, Thomas W.; Jeffers, Peter M.; Russell, Colleen K.; Truex, Michael J.

    2009-09-18

    This report documents a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater for carbon tetrachloride (CT) and chloroform (CF). The study sought also to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. It was funded by the U.S. Department of Energy (DOE) through the Office of Environmental Management Columbia River Protection Supplemental Technologies (CRPST) project and complements work initiated by the Hanford Groundwater Project in FY 2006 that focused primarily on CT in homogenous solution. Work was performed by staff at the Pacific Northwest National Laboratory (PNNL) and the State University of New York at Cortland (SUNY-Cortland).

  20. Apparent removal of the transient tracer carbon tetrachloride from anoxic seawater

    SciTech Connect

    Krysell, M.; Fogelqvist, E.; Tanhua, T. |

    1994-11-01

    Two chlorofluorocarbons (CFC-11 and carbon tetrachloride, CCl4) widely used as tracers for dating water masses, were measured in the Gotland Basin of the Baltic Sea. At the time of the survey, the bottom water of the basin had remained stagnant for 15 years and anoxic for about the same period of time, and the concentrations of both CFC-11 and CCl4 decrease dramatically with depth below the mixed layer. Furthermore, the ratio of CFC-11 to CCl4 increases with depth under the mixed layer along with a steep decrease in oxygen concentration. This is contrary to what would be expected from the atmospheric histories. The most plausible explanation for this is that there is a mechanism whereby the CCl4 is removed from the water mass under anoxic and suboxide conditions.

  1. [Mitochondrial dysfunction and compensatory mechanisms in liver cells during acute carbon tetrachloride-induced rat intoxication].

    PubMed

    Zavodnik, I B

    2015-01-01

    Electron-transport chain and redox-balance of mitochondria are important targets that are damaged during intoxication. The aim of the present work was to estimate the role of impairments in cellular bioenergetic function in the development of liver damage during acute carbon tetrachloride intoxication in rats and to elucidate possible compensatory mechanisms. Acute CCl4-induced rat intoxication (0.8 g/kg or 4 g/kg) resulted in considerable impairments of respiratory and synthetic mitochondrial functions; their manifestations depended on the dose of the toxic agent and the duration of the intoxication increased and accompanied by complete uncoupling of oxidation and phosphorylation processes in liver mitochondria. The intoxication induced considerable liver damage and accumulation of NO in blood plasma and liver tissue. The changes of some parameters of liver mitochondrial functional activity demonstrate an oscillative pattern, reflecting compensatory mechanisms during intoxication that involved increased reduced glutathione level and enhanced succinate dehydrogenase activity. PMID:26716745

  2. Constraining the carbon tetrachloride (CCl4) budget using its global trend and inter-hemispheric gradient

    NASA Astrophysics Data System (ADS)

    Liang, Qing; Newman, Paul A.; Daniel, John S.; Reimann, Stefan; Hall, Bradley D.; Dutton, Geoff; Kuijpers, Lambert J. M.

    2014-07-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance and greenhouse gas and has been regulated under the Montreal Protocol. However, the near-zero 2007-2012 emissions estimate based on the UNEP reported production and feedstock usage cannot be reconciled with the observed slow decline of atmospheric concentrations and the inter-hemispheric gradient (IHG) for CCl4. Our 3-D model simulations suggest that the observed IHG (1.5 ± 0.2 ppt for 2000-2012) is primarily caused by ongoing current emissions, while ocean and soil losses and stratosphere-troposphere exchange together contribute a small negative gradient (~0 - -0.3 ppt). Using the observed CCl4 global trend and IHG, we deduce that the mean global emissions for the 2000-2012 period are 393445 Gg/yr (~30% of the peak 1980s emissions) and a corresponding total lifetime of 353732 years.

  3. Hepatoprotective effects of Calotropis gigantea extract against carbon tetrachloride induced liver injury in rats.

    PubMed

    Lodhi, Gaurav; Singh, Hemant Kumar; Pant, Kamlesh K; Hussain, Zeashan

    2009-03-01

    Ethanolic extract (50 %) of stems of Calotropis gigantea R. Br. (Asclepiadaceae) at doses of 250 and 500 mg kg-1 were studied for hepatoprotective activity in male Wistar rats with liver damage induced using carbon tetrachloride, 2 mL kg-1 twice a week. The protective effect of C. gigantea extract was compared with the standard drug silymarin. Various biochemical parameters such as aspartate amino transferase (AST), alanine amino transferase (ALT), glutathione (GSH), lipid peroxide (LPO), superoxidedismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were evaluated. The results revealed that the C. gigantea extract significantly decreased AST, ALT (p < 0.001) and lipid peroxide (p < 0.01) levels. The antioxidant parameters GSH, GPx, SOD and catalase levels were increased considerably compared to their levels in groups not treated with C. gigantea extract.

  4. Carbon tetrachloride-induced hepatic and renal damages in rat: inhibitory effects of cacao polyphenol.

    PubMed

    Suzuki, Koichiro; Nakagawa, Kiyotaka; Yamamoto, Takayuki; Miyazawa, Taiki; Kimura, Fumiko; Kamei, Masanori; Miyazawa, Teruo

    2015-01-01

    Here, we investigated the protective effect of cacao polyphenol extract (CPE) on carbon tetrachloride (CCl4)-induced hepato-renal oxidative stress in rats. Rats were administered CPE for 7 days and then received intraperitoneal injection of CCl4. Two hours after injection, we found that CCl4 treatment significantly increased biochemical injury markers, lipid peroxides (phosphatidylcholine hydroperoxide (PCOOH) and malondialdehyde (MDA)) and decreased glutathione peroxidase activity in kidney rather than liver, suggesting that kidney is more vulnerable to oxidative stress under the present experimental conditions. CPE supplementation significantly reduced these changes, indicating that this compound has antioxidant properties against CCl4-induced oxidative stress. An inhibitory effect of CPE on CCl4-induced CYP2E1 mRNA degradation may provide an explanation for CPE antioxidant property. Together, these results provide quantitative evidence of the in vivo antioxidant properties of CPE, especially in terms of PCOOH and MDA levels in the kidneys of CCl4-treated rats.

  5. Steam Treated Ordered Mesoporous Carbon Nanomaterials for Catalytic Conversion of Silicon Tetrachloride to Trichlorosilane.

    PubMed

    Kwak, Do-Hwan; Akhtar, M Shaheer; Kim, Ji Man; Yang, O-Bong

    2015-09-01

    The steam-pretreatment on ordered-mesoporous carbon (OMC) catalysts was conducted to improve the catalytic properties for silicon tetrachloride (STC) to trichlorosilane (TCS) conversion. The surface area, pore size and pore volume of OMC were significantly changed as a function of pretreatment temperature. The steam-pretreated OMC at 500 degrees C exhibited the high surface area (-1476.4 m2/g) and pore volume (1.89 cm3/g), which leads the highest conversion rate of 10.8% as compared to bare-OMC (4.3%) and the steam-pretreated OMC. The steam-pretreatment on OMC might increase active oxygenated species, which promoted the generation of active sites of C-O-Si-for high conversion of STC to TCS.

  6. Effects of nanogold on the alleviation of carbon tetrachloride-induced hepatic injury in rats.

    PubMed

    Chen, Yi-Peng; Dai, Zong-Her; Liu, Pan-Chen; Chuu, Jiunn-Jye; Lee, Kuo-Yang; Lee, Shun-Lai; Chen, Yun-Ju

    2012-10-31

    Gold particles have been used in complementary medicine for decades, and many beneficial effects have been reported. Our present study sought to evaluate the therapeutic effects of nanogold in carbon tetrachloride (CCl₄)-injured liver of rats. Male SD rats were subjected to liver injury induction by CCl₄, then the rats were fed with zero to high dose (0, 1, 5 or 10 ppm) of nanogold water every day for 4 weeks. Biochemical analyses on liver functions were then performed to evaluate the therapeutic effects of nanogold. Our results revealed that gold nanoparticles lowered serum aspartate aminotransaminase (AST) and alanine aminotransferase and exerted serum total protein-recovering effects, which might be partially associated with the elevation of anti-inflammatory cytokine IL-10 level. In addition, serum triglyceride level fell after continuous ingestion of nanogold. Finally, the experimental animals recovered body weight after 4 weeks of nanogold ingestion. This is the first report indicating inflammation alleviating effects of nanogold on hepatic injury.

  7. The atmospheric partial lifetime of carbon tetrachloride with respect to the global soil sink

    NASA Astrophysics Data System (ADS)

    Rhew, Robert C.; Happell, James D.

    2016-03-01

    The magnitude of the terrestrial soil sink for atmospheric carbon tetrachloride (CCl4) remains poorly constrained, with the estimated uncertainty range of CCl4 partial lifetimes between ~110 and 910 years. Field observations are sparse, and there are uncertainties in extrapolating these results to the global scale. Here we add to the published CCl4 fluxes with additional field measurements, and we employ a land cover classification scheme based on Advanced Very High Resolution Radiometer measurements that align more closely with the measurement sites to reevaluate the global CCl4 soil sink. We calculate an updated partial lifetime of CCl4 with respect to the soil sink to be 375 (288-536) years, which is 50 to 90% longer than the most recently published best estimates of the soil sink partial lifetime (195 and 245 years). This translates into a longer overall atmospheric lifetime estimate, which is more consistent with the observed atmospheric concentration trend and interhemispheric gradient.

  8. Curcuma longa attenuates carbon tetrachloride-induced oxidative stress in T-lymphocyte subpopulations.

    PubMed

    Abu-Rizq, H A; Mansour, Mohamed H; Afzal, Mohammad

    2015-01-01

    A comparison of crude curcuminoid extract and purified curcumin was made to evaluate the immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced selective cytolytic effects among immature (PNA(+)) thymocytes and peripheral helper (CD4(+)) T lymphocytes in the spleen were paralleled by a significant reduction in CD25, CD71, and Con A receptor expression. Treatment with curcumanoid crude extract, at two different doses, showed a significant restoration of lymphocyte viability and CD25, CD71, and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4(+)) T lymphocytes. Turmeric crude extract, at both low and high dose, was found to be more efficient as compared to purified curcumin, suggesting synergistic effect of curcumin with other components of the crude extract.

  9. Carbon tetrachloride-induced hepatic and renal damages in rat: inhibitory effects of cacao polyphenol.

    PubMed

    Suzuki, Koichiro; Nakagawa, Kiyotaka; Yamamoto, Takayuki; Miyazawa, Taiki; Kimura, Fumiko; Kamei, Masanori; Miyazawa, Teruo

    2015-01-01

    Here, we investigated the protective effect of cacao polyphenol extract (CPE) on carbon tetrachloride (CCl4)-induced hepato-renal oxidative stress in rats. Rats were administered CPE for 7 days and then received intraperitoneal injection of CCl4. Two hours after injection, we found that CCl4 treatment significantly increased biochemical injury markers, lipid peroxides (phosphatidylcholine hydroperoxide (PCOOH) and malondialdehyde (MDA)) and decreased glutathione peroxidase activity in kidney rather than liver, suggesting that kidney is more vulnerable to oxidative stress under the present experimental conditions. CPE supplementation significantly reduced these changes, indicating that this compound has antioxidant properties against CCl4-induced oxidative stress. An inhibitory effect of CPE on CCl4-induced CYP2E1 mRNA degradation may provide an explanation for CPE antioxidant property. Together, these results provide quantitative evidence of the in vivo antioxidant properties of CPE, especially in terms of PCOOH and MDA levels in the kidneys of CCl4-treated rats. PMID:25996516

  10. The spatial distribution of eubacteria and archaea in sand clay columns degrading carbon tetrachloride and methanol

    NASA Astrophysics Data System (ADS)

    Lima, Gláucia da P.; Sleep, Brent E.

    2007-10-01

    The spatial distribution of microbial communities was investigated in anaerobic sand-clay columns fed methanol and carbon tetrachloride (CT). Microbial communities were characterized through analysis of soil samples with denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR) for archaea and eubacteria. Increasing CT inlet concentrations to 29 μM lead to complete inhibition of methanol consumption in both columns. Although low levels of eubacteria and archaea were initially present in the clay soils in both columns, there was no significant microbial growth over 400 days in the clays beyond the interface with the sand zone. Thus, the potential for increased contaminant attenuation in heterogeneous sand-clay systems through biodegradation in the clay matrix zones may be limited in many systems.

  11. [Mitochondrial dysfunction and compensatory mechanisms in liver cells during acute carbon tetrachloride-induced rat intoxication].

    PubMed

    Zavodnik, I B

    2015-01-01

    Electron-transport chain and redox-balance of mitochondria are important targets that are damaged during intoxication. The aim of the present work was to estimate the role of impairments in cellular bioenergetic function in the development of liver damage during acute carbon tetrachloride intoxication in rats and to elucidate possible compensatory mechanisms. Acute CCl4-induced rat intoxication (0.8 g/kg or 4 g/kg) resulted in considerable impairments of respiratory and synthetic mitochondrial functions; their manifestations depended on the dose of the toxic agent and the duration of the intoxication increased and accompanied by complete uncoupling of oxidation and phosphorylation processes in liver mitochondria. The intoxication induced considerable liver damage and accumulation of NO in blood plasma and liver tissue. The changes of some parameters of liver mitochondrial functional activity demonstrate an oscillative pattern, reflecting compensatory mechanisms during intoxication that involved increased reduced glutathione level and enhanced succinate dehydrogenase activity.

  12. A polysaccharide from Dendrobium huoshanense prevents hepatic inflammatory response caused by carbon tetrachloride

    PubMed Central

    Tian, Chang-Cheng; Zha, Xue-Qiang; Luo, Jian-Ping

    2015-01-01

    Dendrobium huoshanense is a precious herbal medicine in China, which exhibits a variety of restorative and therapeutic effects. This study aimed at investigating the hepatoprotective effects of a polysaccharide (DHP1A) isolated from D. huoshanense via water extraction, diethylaminoethyl (DEAE) cellulose anion exchange and size exclusion chromatography. The animal experiment indicated that the oral administration of DHP1A obviously reduced the levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and 8-hydroxy-2′-deoxyguanosine in the serum of mice treated with carbon tetrachloride (CCl4), suggesting the hepatoprotective potential of this polysaccharide. Moreover, DHP1A decreased the expressions of tumor necrosis factor-α, interleukin-1β, monocyte chemoattractant protein-1, macrophage inflammatory protein-2, CD68 and phosphorylated IκBα (p-IκBα) in the CCl4-treated mice. These results revealed that the hepatoprotective effect of DHP1A was partly attributed to its anti-inflammatory action. PMID:26019626

  13. Protective effects of pomegranate (Punica granatum) juice on testes against carbon tetrachloride intoxication in rats

    PubMed Central

    2014-01-01

    Background Pomegranate fruit has been extensively used as a natural medicine in many cultures. The present study was aimed at evaluating the protective effects of pomegranate (Punica granatum) juice against carbon tetrachloride (CCl4)-induced oxidative stress and testes injury in adult Wistar rats. Methods Twenty eight Wistar albino male rats were divided equally into 4 groups for the assessment of protective potential of pomegranate juice. Rats of group I (control) received only vehicles and had free access to food and water. Rats of groups II and IV were treated with CCl4 (2 ml/kg bwt) via the intraperitoneal route once a week for ten weeks. The pomegranate juice was supplemented via drinking water 2 weeks before and concurrent with CCl4 treatment to group IV. Group III was supplemented with pomegranate juice for twelve weeks. The protective effects of pomegranate on serum sex hormones, oxidative markers, activities of antioxidant enzymes and histopathology of testes were determined in CCl4-induced reproductive toxicity in rats. Results Pomegranate juice showed significant elevation in testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) those depleted by the injection of CCl4. Activity levels of endogenous testesticular antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) and glutathione (GSH) contents were increased while lipid peroxidation (LPO) and nitric oxide (NO) were decreased with pomegranate juice. Moreover, degeneration of germ and Leydig cells along with deformities in spermatogenesis induced after CCl4 injections were restored with the treatment of pomegranate juice. Conclusion The results clearly demonstrated that pomegranate juice augments the antioxidant defense mechanism against carbon tetrachloride-induced reproductive toxicity and provides evidence that it may have a therapeutic role in free radical mediated

  14. Improved Predictions of Carbon Tetrachloride Contaminant Flow and Transport: Implementation of Kinetic Volatilization and Multicomponent NAPL Behavior

    SciTech Connect

    Oostrom, Martinus; Zhang, Z. F.; Freedman, Vicky L.; Tartakovsky, Guzel D.

    2008-09-29

    Carbon tetrachloride (CT) was discharged to waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. The RI/FS process and remedial investigations for the 200-PW-1, 200 PW-3, and 200-PW-6 Operable Units are described in the Plutonium/Organic-Rich Process Condensate/Process Waste Groups Operable Unit RI/FS Work Plan. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the STOMP simulator (White and Oostrom, 2006) by incorporating kinetic volatilization of nonaqueous phase liquids (NAPL) and multicomponent flow and transport. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy. Previous numerical simulation results with the STOMP simulator have overestimated the effect of soil vapor extraction (SVE) on subsurface CT, showing rapid removal of considerably more CT than has actually been recovered so far. These previous multiphase simulations modeled CT mass transfer between phases based on equilibrium partitioning. Equilibrium volatilization can overestimate volatilization because mass transfer limitations present in the field are not considered. Previous simulations were also conducted by modeling the NAPL as a single component, CT. In reality, however, the NAPL mixture disposed of at the Hanford site contained several non-volatile and nearly insoluble organic components, resulting in time-variant fluid properties as the CT component volatilized or dissolved over time. Simulation of CT removal from a DNAPL mixture using single-component DNAPL properties typically leads to an overestimation of CT removal. Other possible reasons for the discrepancy between

  15. An alternate metabolic hypothesis for a binary mixture of trichloroethylene and carbon tetrachloride: application of physiologically based pharmacokinetic (PBPK) modeling in rats.

    EPA Science Inventory

    Carbon tetrachloride (CC4) and trichloroethylene (TCE) are hepatotoxic volatile organic compounds (VOCs) and environmental contaminants. Previous physiologically based pharmacokinetic (PBPK) models describe the kinetics ofindividual chemical disposition and metabolic clearance fo...

  16. Reaction of carbon tetrachloride with methane in a non-equilibrium plasma at atmospheric pressure, and characterisation of the polymer thus formed.

    PubMed

    Gaikwad, Vaibhav; Kennedy, Eric; Mackie, John; Holdsworth, Clovia; Molloy, Scott; Kundu, Sazal; Stockenhuber, Michael; Dlugogorski, Bogdan

    2014-09-15

    In this paper we focus on the development of a methodology for treatment of carbon tetrachloride utilising a non-equilibrium plasma operating at atmospheric pressure, which is not singularly aimed at destroying carbon tetrachloride but rather at converting it to a non-hazardous, potentially valuable commodity. This method encompasses the reaction of carbon tetrachloride and methane, with argon as a carrier gas, in a quartz dielectric barrier discharge reactor. The reaction is performed under non-oxidative conditions. Possible pathways for formation of major products based on experimental results and supported by quantum chemical calculations are outlined in the paper. We elucidate important parameters such as carbon tetrachloride conversion, product distribution, mass balance and characterise the chlorinated polymer formed in the process.

  17. ESTABLISHING CHANGES IN METABOLISM OF CARBON TETRACHLORIDE IN THE PRESENCE OF TRICHLOROETHYLENE IN THE RAT THROUGH THE USE OF PHYSIOLOGICALLY BASED PHARMACOKINETIC (PBPK) MODELING

    EPA Science Inventory

    Toxicological interactions of chemicals can affect metabolism, often decreasing overall associated metabolic rates; and changes in metabolism can be evaluated through the use of mathematical models. Trichloroethylene (TCE) and carbon tetrachloride (CCl4) are common co...

  18. Reductive Dechlorination of Carbon Tetrachloride by Tetrachloroethene and Trichloroethene Respiring Anaerobic Mixed Cultures

    NASA Astrophysics Data System (ADS)

    Vickstrom, K. E.; Azizian, M.; Semprini, L.

    2015-12-01

    Carbon tetrachloride (CT) is a toxic and recalcitrant groundwater contaminant with the potential to form a broad range of transformation products. Of the possible biochemical pathways through which CT can be degraded, reductive dehalogenation to less chlorinated compounds and mineralization to carbon dioxide (CO2) appear to be the most frequently utilized pathways by anaerobic organisms. Results will be presented from batch experiments of CT degradation by the Evanite (EV), Victoria Strain (VS) and Point Mugu (PM) anaerobic dechlorinating cultures. The cultures are grown in chemostats and are capable of transforming tetrachloroethene (PCE) or trichloroethene (TCE) to ethene by halorespiration via reductive dehalogenase enzymes. For the batch CT transformation tests, the cells along with supernatant were harvested from chemostats fed PCE or TCE, but never CT. The batch reactors were initially fed 0.0085 mM CT and an excess of formate (EV and VS) or lactate (PM) as electron donor. Transformation of CT was 100% with about 20% converted to chloroform (CF) and undetected products. Multiple additions of CT showed a slowing of pseudo first-order CT transformation rates across all cultures. Batch reactors were then established and fed 0.085 mM CT with an excess of electron donor in order to better quantify the reductive pathway. CT was transformed to CF and dichloromethane (DCM), with trace amounts of chloromethane (CM) detected. Between 60-90% of the mass added to the system was accounted for, showing that the majority of the carbon tetrachloride present is being reductively dehalogenated. Results from batch reactors that were poisoned using sodium azide, and from reactors not provided electron donor will be presented to distinguish between biotic and abiotic reactions. Furthermore, results from reactors prepared with acetylene (a potent, reversible inhibitor of reductive dehalogenases (1)) will be presented as a means of identifying the enzymes involved in the

  19. Physiological factors affecting carbon tetrachloride dehalogenation by the denitrifying bacterium Pseudomonas sp. strain KC.

    PubMed Central

    Lewis, T A; Crawford, R L

    1993-01-01

    Pseudomonas sp. strain KC was grown on a medium with a low content of transition metals in order to examine the conditions for carbon tetrachloride (CT) transformation. Several carbon sources, including acetate, glucose, glycerol, and glutamate, were able to support CT transformation. The chelators 2,2'-dipyridyl and 1,10-phenanthroline stimulated CT transformation in a rich medium that otherwise did not support this activity. Low (< 10 microM) additions of dissolved iron(II), iron(III), and cobalt(II), as well as an insoluble iron(III) compound, ferric oxyhydroxide, inhibited CT transformation. The addition of 50 microM iron to actively growing cultures resulted in delayed inhibition of CT transformation. CT transformation was seen in aerobic cultures of KC, but with reduced efficiency compared with denitrifying cultures. Inhibition of CT transformation by iron was also seen in aerobically grown cultures. Optimal conditions were used in searching for effective CT transformation activity among denitrifying enrichments grown from samples of aquifer material. No activity comparable to that of Pseudomonas sp. strain KC was found among 16 samples tested. PMID:8517754

  20. Efficient dechlorination of carbon tetrachloride by hydrophobic green rust intercalated with dodecanoate anions.

    PubMed

    Ayala-Luis, Karina B; Cooper, Nicola G A; Koch, Christian Bender; Hansen, Hans Christian B

    2012-03-20

    The reductive dechlorination of carbon tetrachloride (CT) by Fe(II)-Fe(III) hydroxide (green rust) intercalated with dodecanoate, Fe(II)(4)Fe(III)(2)(OH)(12)(C(12)H(23)O(2))(2) · yH(2)O (designated GR(C12)), at pH ~ 8 and at room temperature was investigated. CT at concentration levels similar to those found in heavily contaminated groundwater close to polluted industrial sites (14-988 μM) was reduced mainly to the fully dechlorinated products carbon monoxide (CO, yields >54%) and formic acid (HCOOH, yields >6%). Minor formation of chloroform (CF), the only chlorinated degradation product, was also detected (yields <6.3%). Reactions carried out with excess GR followed pseudo first-order kinetics with respect to CT with rate constants ranging from 6.5 × 10(-2) to 0.47 h(-1). These rate constants are comparable to those measured for CT dechlorinations mediated by zerovalent iron. Reduction of the highest concentration of CT (1.4 mM) proceeds until 56% of the Fe(II) sites of GR(C12) was consumed. This reaction ceased after 10 h due to surface passivation of GR(C12).

  1. Chemopreventive Effect of Cinnamon Extract on Carbon Tetrachloride-Induced Physiological Changes in the Frog, Rana ridibunda

    NASA Astrophysics Data System (ADS)

    Al-Attar, Atef M.

    The present study examined the preventive influences of an aqueous extract of cinnamon on carbon tetrachloride-induced some physiological alterations in the frog, Rana ridibunda. The experimental animals were divided into five batches. The first batch was untreated and served as control. The other batches were treated for 6 weeks with carbon tetrachloride, cinnamon extract plus carbon tetrachloride, cinnamon and corn oil, respectively. Haematological, biochemical and hepatosomatic index indices were chosen as physiological indicators. These parameters were evaluated at 2, 4 and 6 weeks. In comparison with control and cinnamon plus CCl4 batches, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, mean corpuscular haemoglobin concentration and increases of glutamic pyruvic acid transaminase values were noted in CCl4-exposed batch at all experimental periods. Also, glutamic oxaloacetic acid transaminase and hepatosomatic index levels were significantly elevated, while mean corpuscular haemoglobin values were decreased at second and last periods. Mean cell volume values were only increased at the first period. In comparison with control batch, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, and increases of glutamic oxaloacetic acid transaminase, glutamic pyruvic acid transaminase and hepatosomatic index values were observed in frogs treated with cinnamon plus CCl4 at 2 and 6 weeks. Mean cell volume and mean corpuscular haemoglobin values were statistically elevated at second period. Mean corpuscular haemoglobin concentration values were declined at last period. Moreover, the percentage changes of these parameters in cinnamon plus CCl4 batch tended to be lower than CCl4 treated the experimental animals. In addition, it is conceivable therefore, that the cinnamon aqueous extract exhibits a protective influence against carbon tetrachloride-induced some physiological changes, probably mediated

  2. Protection effect of kallistatin on carbon tetrachloride-induced liver fibrosis in rats via antioxidative stress.

    PubMed

    Huang, Xiaoping; Wang, Xiao; Lv, Yinghui; Xu, Luli; Lin, Junsheng; Diao, Yong

    2014-01-01

    Prolonged inflammation and oxidative stress are emerging as key causes of pathological wound healing and the development of liver fibrosis. We have investigated the effects of recombinant human kallistatin, produced in Pichia. pastoris, on preventing carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Daily administration of kallistatin prevented development of CCl4-induced liver fibrosis, which was evidenced by histological study. In all kallistatin treated rats, activation of hepatic stellate cells (HSC) as assessed by s-smooth muscle actin staining was attenuated, TGF- β1 expression was inhibited, class I serum biomarkers associated with the process of fibrogenesis, such as hyaluronic acid, laminin, and procollagen III, were lowered, compared with that in the model control group. Furthermore, residual hepatic functional reserve was improved by kallistatin treatment. CCl4 induced elevation of malondialdehyde level and reduced superoxide dismutase activity in the liver, while kallistatin reduced these oxidative parameters. We also investigated the effects of kallistatin on rat primary HSC and LX-2, the human HSC cell line. Kallistatin scavenged H2O2-induced ROS in the LX-2 cells, and suppressed the activation of primary HSC. These results suggest recombinant human kallistatin might be a promising drug candidate for therapeutic intervention of liver fibrosis. PMID:24558397

  3. Protective Effects of Polydatin from Polygonum cuspidatum against Carbon Tetrachloride-Induced Liver Injury in Mice

    PubMed Central

    Zhang, Hong; Yu, Cheng-Hao; Jiang, Yi-Ping; Peng, Cheng; He, Kun; Tang, Jian-Yuan; Xin, Hai-Liang

    2012-01-01

    Polydatin is one of main compounds in Polygonum cuspidatum, a plant with both medicinal and nutritional value. The possible hepatoprotective effects of polydatin on acute liver injury mice induced by carbon tetrachloride (CCl4) and the mechanisms involved were investigated. Intraperitoneal injection of CCl4 (50 µl/kg) resulted in a significant increase in the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and hepatic malondialdehyde (MDA), also a marked enhancement in the expression of hepatic tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and nuclearfactor-kappa B (NF-κB). On the other hand, decreased glutathione (GSH) content and activities of glutathione transferase (GST), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were observed following CCl4 exposure. Nevertheless, all of these phenotypes were evidently reversed by preadministration of polydatin for 5 continuous days. The mRNA and protein expression levels of hepatic growth factor-beta1 (TGF-β1) were enhanced further by polydatin. These results suggest that polydatin protects mice against CCl4-induced liver injury through antioxidant stress and antiinflammatory effects. Polydatin may be an effective hepatoprotective agent and a promising candidate for the treatment of oxidative stress- and inflammation-related diseases. PMID:23029551

  4. D-Pinitol Protects Against Carbon Tetrachloride-Induced Hepatotoxicity in Rats.

    PubMed

    Rengarajan, Thamaraiselvan; Rajendran, Peramaiyan; Nandakumar, Natarajan; Lokeshkumar, Boobathy; Balasubramanian, Maruthaiveeran Periyasamy

    2015-01-01

    The aim of the study was to evaluate the protective activity of D-Pinitol against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The animals were divided into six groups, with each group consisting of six animals. Group I animals served as normal controls and received olive oil vehicle (1.0 ml/kg body weight intraperitoneally). Group II rats served as CCl4 controls, which received 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks. Group III rats were treated with 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks, followed by D-Pinitol (100 mg/kg body weight) given for 28 days intragastrically. Group IV rats received D-Pinitol alone at a concentration of 100 mg/kg body weight for 28 days intragastrically. At the end of the experimental period, serum marker enzymes and lipid peroxidation (LPO) levels were significantly increased in group II animals. On the other hand, D-Pinitol treatment significantly decreased marker enzymes and LPO levels and increased the antioxidant level. CYP expression was also investigated. Therefore, the present study revealed that D-Pinitol acts as a protective agent by decreasing metabolic activation of xenobiotics through its antioxidant nature.

  5. Antioxidant and protective effects of Phytocee™ against carbon tetrachloride-induced oxidative stress

    PubMed Central

    Joseph, Joshua Allan; Radhakrishnan, Uma; Mutyala, Sridhar; Goudar, Krishnagouda Shankargouda; Ayyappan, Usha Parackal Thachappully; Agarwal, Amit

    2015-01-01

    Background: This study evaluated the antioxidant potential of a polyherbal formulation (Phytocee™) in the rodent model. Materials and Methods: Four groups of rats (n = 6) were pretreated with Vitamin C (20 mg/kg) or Phytocee™ (20, 100, and 200 mg/kg), respectively for 10 days. Oxidative stress in rat liver was induced by administration of carbon tetrachloride (CCl4) at 2 ml/kg as a single dose orally to all groups except the vehicle control group. After 24 h of administration of CCl4, hepatic levels of malondialdehyde (MDA), serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic superoxide dismutase (SOD), catalase, and reduced glutathione (GSH) levels were evaluated. Results: Phytocee™ administered groups at all the dose levels significantly reduced the hepatic MDA, serum ALT and AST levels with a marked increase in hepatic SOD and catalase as compared with CCl4 treated group. Conclusion: The findings suggest that Phytocee™ markedly reversed the effects of CCl4 induced oxidative stress and can be used as an antioxidant feed supplement. PMID:25810658

  6. Evaluation of hepatoprotective effect of Amalkadi Ghrita against carbon tetrachloride-induced hepatic damage in rats.

    PubMed

    Achliya, Girish S; Wadodkar, Sudhir G; Dorle, Avinash K

    2004-02-01

    Amalkadi Ghrita (AG), a polyherbal formulation, was evaluated for its hepatoprotective activity against carbon tetrachloride (CCl4)-induced hepatic damage in rats. The hepatoprotective activity of AG was evaluated by measuring levels of serum marker enzymes like serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), and acid phosphatase (ACP). The serum levels of total proteins and bilirubin were also estimated. The histological studies were also carried out to support the above parameters. Silymarin was used as standard drug. Administration of AG (100 and 300 mg/kg, p.o.) markedly prevented CCl4-induced elevation of levels of serum GPT, GOT, ACP, ALP, and bilirubin. The decreased level of total proteins due to hepatic damage induced by CCl4 was found to be increased in AG-treated group. The results are comparable to that of silymarin. A comparative histopathological study of liver exhibited almost normal architecture, as compared to CCl4-treated group. Hepatoprotective effect of AG is probably due to combined action of all ingredients. PMID:15013185

  7. Calretinin immunoreactivity in normal and carbon tetrachloride-induced nephrotoxic rats.

    PubMed

    Kang, Ki Young; Kim, Jin Nam; Chang, In Youb; Park, Sung Ho; Yoon, Sang Pil

    2011-11-01

    Carbon tetrachloride (CCl(4)) is a potent hepatotoxic and nephrotoxic chemical. Little, however, is known about the association of CCl(4)-induced nephrotoxicity and calretinin. We hypothesized that calretinin might be localized in the proximal tubule cells and play a role against CCl(4)-induced nephrotoxicity, since the target of CCl(4) is the brush border-bearing tubule cells. CCl(4) (1 ml/kg) was administrated by oral gavage to 8-week old male Sprague-Dawley rats once a week for 4 weeks. A significant increase in serum blood urea nitrogen and creatinine was confirmed by serum analysis. Calretinin immunolocalization was compared with the calbindin D-28k immunoreactivity in normal and CCl(4)-treated kidneys. Calretinin was clearly immunolocalized in the apical surface of proximal convoluted tubule in the deeper cortex of normal kidney and blurred after CCl(4) administration, with only minor changes of calbindin D-28k immunoreactivity in the distal convoluted tubules and collecting ducts, irrelevant to the CCl(4) treatment. These findings might have significance since decreased immunolocalization of calretinin with CCl(4)-induced nephrotoxicity may contribute to the toxicity-related decrease in calcium transport or calcium buffering activity in the kidney. PMID:20947139

  8. Liver fibrosis in mice induced by carbon tetrachloride and its reversion by luteolin

    SciTech Connect

    Domitrovic, Robert; Jakovac, Hrvoje; Tomac, Jelena; Sain, Ivana

    2009-12-15

    Hepatic fibrosis is effusive wound healing process in which excessive connective tissue builds up in the liver. Because specific treatments to stop progressive fibrosis of the liver are not available, we have investigated the effects of luteolin on carbon tetrachloride (CCl{sub 4})-induced hepatic fibrosis. Male Balb/C mice were treated with CCl{sub 4} (0.4 ml/kg) intraperitoneally (i.p.), twice a week for 6 weeks. Luteolin was administered i.p. once daily for next 2 weeks, in doses of 10, 25, and 50 mg/kg of body weight. The CCl{sub 4} control group has been observed for spontaneous reversion of fibrosis. CCl{sub 4}-intoxication increased serum aminotransferase and alkaline phosphatase levels and disturbed hepatic antioxidative status. Most of these parameters were spontaneously normalized in the CCl{sub 4} control group, although the progression of liver fibrosis was observed histologically. Luteolin treatment has increased hepatic matrix metalloproteinase-9 levels and metallothionein (MT) I/II expression, eliminated fibrinous deposits and restored architecture of the liver in a dose-dependent manner. Concomitantly, the expression of glial fibrillary acidic protein and alpha-smooth muscle actin indicated deactivation of hepatic stellate cells. Our results suggest the therapeutic effects of luteolin on CCl{sub 4}-induced liver fibrosis by promoting extracellular matrix degradation in the fibrotic liver tissue and the strong enhancement of hepatic regenerative capability, with MTs as a critical mediator of liver regeneration.

  9. Nanoparticle Based Delivery of Quercetin for the Treatment of Carbon Tetrachloride Mediated Liver Cirrhosis in Rats.

    PubMed

    Verma, Shashi Kant; Rastogil, Shweta; Arora, Indu; Javed, Kalim; Akhtar, Mohd; Samim, Mohd

    2016-02-01

    Liver fibrosis is the common response to chronic liver injury and ultimately leads to cirrhosis. There is a pressing need in the pharmaceutical industry to develop efficient well-targeted drug delivery systems, which are lacking to date. This study was designed to investigate the efficacy of a nanoquercetin NQ; i.e., quercetin encapsulated in PAG (p-aminophenyl-1-thio-β-D-galactopryranoside)-coated NIPAAM (N-isopropyl acrylamide) nanopolymer in liver compared with naked quercetin (Q) using a carbon tetrachloride (CCl₄)-mediated liver cirrhosis model. NQ was more effective at restoring liver membrane integrity as indicated by significantly reduced serum markers, including Alanine Transaminase (ALT), Aspartate Aminotransferase (AST), Alkaline Phosphatase (ALP) and Lactate Dehydrogenase (LDH), compared with naked Q. The findings of reduced collagen and histopathology also show that the NQ effects were much better than those of naked Q. Biochemical parameters, including antioxidant defense enzymes, also provide supporting evidence. Furthermore, the decrease in NF-κB and NOS-2 expression in the NQ-treated groups was also much stronger than in the naked Q-treated group. Thus, the data clearly suggest that NQ not only provides significant hepatoprotection compared with naked Q, but it also substantially lowered the required concentration (1,000 to 10,000-fold lower) by increasing the bioavailability. PMID:27305761

  10. Sesamin ameliorates oxidative liver injury induced by carbon tetrachloride in rat

    PubMed Central

    Lv, Dan; Zhu, Chang-Qing; Liu, Li

    2015-01-01

    Sesamin is naturally occurring lignan from sesame oil with putative antioxidant property. The present study was designed to investigate the protective role of sesamin against carbon tetrachloride induced oxidative liver injury. Male Wistar albino rats (180-200 g) were divided in to 5 groups (n=6). Hepatotoxicity was induced by the administration of CCl4 (0.1 ml/100 g bw., 50% v/v with olive oil) intraperitoneally. Sesamin was administered in two different dose (5 and 10 ml/kg bw) to evaluate the hepatoprotective activity. Sesamin significantly reduced the elevated serum liver marker enzymes (P<0.0001). Reduction of TBARS (P<0.01 and P<0.001) followed by enhancement of GSH., SOD and catalase (P<0.0001) in liver homogenate in sesamin treated groups shows the amelioration of oxidative stress induced by CCl4. Histopathological report also supported the hepatoprotection offered by sesamin. Sesamin effects in both the dose were in comparable to reference standard drug silymarin. From these above findings it has been concluded that sesamin ameliorate the oxidative liver injury in terms of reduction of lipid peroxidation and enhancement of liver antioxidant enzymes. PMID:26191289

  11. The protective role of pomegranate juice against carbon tetrachloride-induced oxidative stress in rats.

    PubMed

    Pirinççioğlu, Mihdiye; Kızıl, Göksel; Kızıl, Murat; Kanay, Zeki; Ketani, Aydın

    2014-11-01

    Most pomegranate (Punica granatum Linn., Punicaceae) fruit parts are known to possess enormous antioxidant activity. The present study was carried out to determine the phenolic and flavonoid contents of Derik pomegranate juice and determine its effect against carbon tetrachloride (CCl4)-induced toxicity in rats. Animals were divided into four groups (n = 6): group I: control, group II: CCl4 (1 ml/kg), group III: CCl4 + pomegranate juice and group IV: CCl4 + ursodeoxycholic acid (UDCA). Treatment duration was 4 weeks, and the dose of CCl4 was administered once a week to groups II, III and IV during the experimental period. CCl4-treated rats caused a significant increase in serum enzyme levels, such as aspartate aminotransferase, alanine aminotransferase and total bilirubin, and decrease in albumin, when compared with control. Administration of CCl4 along with pomegranate juice or UDCA significantly reduces these changes. Analysis of lipid peroxide (LPO) levels by thiobarbutiric acid reaction showed a significant increase in liver, kidney and brain tissues of CCl4-treated rats. However, both pomegranate juice and UDCA prevented the increase in LPO level. Histopathological reports also revealed that there is a regenerative activity in the liver and kidney cells. Derik pomegranate juice showed to be hepatoprotective against CCl4-induced hepatic injury. In conclusion, present study reveals a biological evidence that supports the use of pomegranate juice in the treatment of chemical-induced hepatotoxicity.

  12. Effects of ethanol and carbon tetrachloride upon vitamin A status of rats

    SciTech Connect

    McCauley, K.; Prabhudesai, M.; Erdman, J.W. Jr.

    1986-05-01

    The effects of ethanol (ET) and carbon tetrachloride (CCL/sub 4/) upon tissue vitamin A, liver lipids, liver cytochrome P/sub 450/ and hepatic morphology were investigated. After a two week feeding period, young male rats were divided into four groups. For 5 weeks one group of rats (n=18) received ET in liquid diets (30% of calories) while another (n=8) was exposed to CCL/sub 4/ inhalation twice a week along with phenobarbitol in the diet. All groups received the NRC recommended level for vitamin A. Comparison of ET and its pair-fed control group revealed; decreased hepatic vitamin A, no change in serum vitamin A, increased % liver lipid and cytochrome P/sub 450/ with minimal fat accumulation in hepatocytes. Comparison of CCL/sub 4/ group with pair-fed controls showed; increased serum vitamin A, decreased hepatic vitamin A, increased cytochrome P/sub 450/, marked hepatic fat accumulation, hepatic cell necrosis and early cirrhosis. Thus, CCL/sub 4/, which is a more potent hepatotoxin as evidenced by a more elevated cytochrome P/sub 450/ and distorted liver morphology, not only reduced liver vitamin A, but also increased serum vitamin A. The hepatic response to CCL/sub 4/ may mimic a more cirrhotic condition such as that resulting from longer-termed ET intake.

  13. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride.

    PubMed

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y Mauricio; Vrabec, Jadran

    2016-03-28

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values. PMID:27036455

  14. Carbon Tetrachloride at Hepatotoxic Levels Blocks Reversibly Gap Junctions between Rat Hepatocytes

    NASA Astrophysics Data System (ADS)

    Saez, J. C.; Bennett, M. V. L.; Spray, D. C.

    1987-05-01

    Electrical coupling and dye coupling between pairs of rat hepatocytes were reversibly reduced by brief exposure to halogenated methanes (CBrCl3, CCl4, and CHCl3). The potency of different halomethanes in uncoupling hepatocytes was comparable to their hepatotoxicity in vivo, and the rank order was the same as that of their tendency to form free radicals. The effect of carbon tetrachloride (CCl4) on hepatocytes was substantially reduced by prior treatment with SKF 525A, an inhibitor of cytochrome P-450, and by exposure to the reducing reagent β -mercaptoethanol. Halomethane uncoupling occurred with or without extracellular calcium and did not change intracellular concentrations of calcium and hydrogen ions or the phosphorylation state of the main gap-junctional protein. Thus the uncoupling appears to depend on cytochrome P-450 oxidative metabolism in which free radicals are generated and may result from oxidation of the gap-junctional protein or of a regulatory molecule that leads to closure of gap-junctional channels. Decreases in junctional conductance may be a rapid cellular response to injury that protects healthy cells by uncoupling them from unhealthy ones.

  15. Improved risk estimates for carbon tetrachloride. Project status report and technical progress report

    SciTech Connect

    Benson, J.M.; Nikula, K.J.; Barr, E.B.; Springer, D.L.; Thrall, K.D.

    1997-09-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. High levels of CCl{sub 4} at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The overall purpose of these studies is to improve the scientific basis for assessing the health risk associated with human exposure to CCl{sub 4}. Specifically, the authors will determine the toxicokinetics of inhaled and ingested CCl{sub 4} in F344/Crl rats. B6C3F{sub 1} mice, and Syrian hamsters. They will also evaluate species differences in the metabolism of CCl{sub 4} by rats, mice, hamsters, and man. Dose-response relationships will be determined in all these studies. This information will be used to improve the physiologically based pharmacokinetic (PBPK) model for CCl{sub 4} originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). The authors will also provide scientific evidence that CCl{sub 4}, like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation.

  16. Hepatoprotective activity of Leptadenia reticulata stems against carbon tetrachloride-induced hepatotoxicity in rats

    PubMed Central

    Nema, Amit Kumar; Agarwal, Abhinav; Kashaw, Varsha

    2011-01-01

    Objective: To evaluate the hepatoprotective activity of ethanolic and aqueous extract of stems of Leptadenia reticulata (Retz.) Wight. and Arn. in carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Materials and Methods: The toxicant CCl4 was used to induce hepatotoxicity at a dose of 1.25 ml/kg as 1 : 1 mixture with olive oil. Ethanolic and aqueous extracts of L. reticulata stems were administered in the doses of 250 and 500 mg/kg/day orally for 7 days. Silymarin (50 mg/kg) was used as standard drug. The hepatoprotective effect of these extracts was evaluated by the assessment of biochemical parameters such as serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, total bilirubin, serum protein, and histopathological studies of the liver. Results: Treatment of animals with ethanolic and aqueous extracts significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver as indicated by lower levels of serum bilirubin and protein as compared with the normal and silymarin-treated groups. Histology of the liver sections confirmed that the extracts prevented hepatic damage induced by CCl4 showing the presence of normal hepatic cords, absence of necrosis, and fatty infiltration. Conclusion: The ethanolic and aqueous extracts of stems of L. reticulata showed significant hepatoprotective activity. The ethanolic extract is more potent in hepatoprotection in CCl4-indiced liver injury model as compared with aqueous extract. PMID:21713086

  17. Iron-Sulfide-Associated Products Formed during Reductive Dechlorination of Carbon Tetrachloride.

    PubMed

    Lan, Ying; Butler, Elizabeth C

    2016-06-01

    This paper investigated the mackinawite (FeS)-associated products formed during reaction between FeS and carbon tetrachloride (CT) at pH 7 and 8. At pH 8, reaction of FeS with CT led to formation of abundant spherical particles with diameters between 50 and 400 nm on the FeS surface and in solution; far fewer such particles were observed at pH 7. Analysis of the FeS surface by energy dispersive X-ray spectroscopy after reaction with CT at pH 8 showed decreased sulfur and elevated oxygen compared to unreacted FeS. The spherical particles that formed upon FeS reaction with CT were mostly amorphous with localized areas of poorly crystalline two-line ferrihydrite. X-ray photoelectron spectroscopy indicated that the predominant Fe surface species after reaction with CT at pH 8 was Fe(III)-O, consistent with ferrihydrite and other amorphous iron (hydr)oxides as major products. Powder X-ray diffraction analysis suggested formation of greigite upon reaction of FeS with CT at pH 7. Both ferrihydrite and Fe(2+), which is a product of greigite dissolution, can react with dissolved HS(-) to form FeS, suggesting that, after oxidation by chlorinated aliphatics, FeS can be regenerated by addition or microbial generation of sulfide.

  18. Healing and Preventive Effects of Calcium Alginate on Carbon Tetrachloride Induced Liver Injury in Rats

    PubMed Central

    Khotimchenko, Yuri S.; Khotimchenko, Maxim Y.

    2004-01-01

    The purpose of this study was to investigate the pharmacological effects of calcium alginate on carbon tetrachloride (CCL4)-induced hepatotoxicity in rats. The study included two experiments. In the first experiment the animals were given daily CCL4 through gavage for 7 days and then 10, 50, or 250 mg/kg b.w. of calcium alginate for 21 days. The increased bilirubin level, enhanced alanine and aspartate aminotransferase activity in plasma and reduced liver glycogen content induced by CCL4 were partly normalized by alginate administration in a dose-dependent manner. In addition, alginate significantly improved CCL4-induced alterations of pro-oxidant and antioxidant biochemical parameters in liver and plasma compared to those of rats administered CCL4. In the second experiment the animals were given daily 10, 50 or 250 mg/kg b.w. of calcium alginate for 21 days before 7-day administration of CCL4. Pretreatment with alginate before CCL4 administration resulted in significantly inhibited increase of the blood enzymatic activities of alanine and aspartate aminotransferases and bilirubin level in a dose-dependent manner. Also, preliminary administration of alginate prevented elevation of lipid peroxidation products and reduction of liver glutathione content in rats given CCL4. These results suggest that calcium alginate exerts healing and preventive effects on CCL4-induced hepatotoxicity in rats.

  19. Ameliorative effect of Phytocee™ Cool against carbon tetrachloride-induced oxidative stress

    PubMed Central

    Joseph, Joshua Allan; Ayyappan, Usha Parackal Thachappully; Sasidharan, Suja Rani; Mutyala, Sridhar; Goudar, Krishnagouda Shankargouda; Agarwal, Amit

    2014-01-01

    Background: Antioxidants from natural sources have a major role in reversing the effects of oxidative stress and promoting health, growth and productivity in animals. Objective: This study was undertaken to investigate the possible antioxidant activity and hepatoprotective effects of Phytocee™ Cool on carbon tetrachloride (CCl4) induced oxidative stress and liver damage in rats. Materials and Methods: Animals were pretreated with Phytocee™ Cool for 10 days and were challenged with CCl4 (1:1 v/v) in olive oil on the 10th day. After 24 h of CCl4 administration blood was collected and markers of hepatocellular damage aspartate aminotransferase (AST), alanine aminotransferase (ALT) were evaluated. Rats were sacrificed and oxidative stress in liver was estimated using malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase. Results: CCl4 caused a significant increase in serum AST, ALT, hepatic MDA and GSH levels, whereas the SOD and catalase activities were decreased. Phytocee™ Cool pretreatment attenuated the MDA, AST ALT levels and increased the activities of SOD and catalase. Conclusion: Phytocee™ Cool demonstrated antioxidant potential and hepatoprotective effects and plausibly be used in the amelioration of oxidative stress. PMID:25276070

  20. Hepatoprotective effect of trimethylgallic acid esters against carbon tetrachloride-induced liver injury in rats.

    PubMed

    Sachdeva, Mamta; Chadha, Renu; Kumar, Anil; Karan, Maninder; Singh, Tejvir; Dhingra, Sameer

    2015-12-01

    Gallic acid and its derivatives are potential therapeutic agents for treating various oxidative stress mediated disorders. In the present study, we investigated the hepatoprotective effects of newly synthesized conjugated trimethylgallic acid (TMGA) esters against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Animals were pre-treated with TMGA esters at their respective doses for 7 days against CCl4-induced hepatotoxicity. The histopathological changes were evaluated to find out degenerative fatty changes including vacuole formation, inflammation and tissue necrosis. Various biomarkers of oxidative stress (lipid peroxidation, glutathione levels, and endogenous antioxidant enzyme activities), liver enzymes (AST and ALT), triacylglycerol and cholesterol were evaluated. Pre-treatment with TMGA esters (MRG, MGG, MSG, and MUG at the dose of 28.71, 30.03, 31.35, 33.62 mg/kg/day), respectively reversed the CCl4-induced liver injury scores (reduced vacuole formation, inflammation and necrosis), biochemical parameters of plasma (increased AST, ALT, TG, and cholesterol), antioxidant enzymes (increased lipid peroxidation and nitrite levels; decreased glutathione levels, superoxide dismutase and catalase activities) in liver tissues and inflammatory surge (serum TNF-α) significantly. The study revealed that TMGA esters exerted hepatoprotective effects in CCl4-induced rats, specifically by modulating oxidative-nitrosative stress and inflammation.

  1. Motility-enhanced bioremediation of carbon tetrachloride-contaminated aquifer sediments

    SciTech Connect

    Witt, M.E.; Dybas, M.J.; Worden, R.M.; Criddle, C.S.

    1999-09-01

    Pseudomonas stutzeri KC is an aquifer isolate capable of denitrification and cometabolic transformation of carbon tetrachloride (CT) under anoxic conditions. Capillary experiments established that strain KC is chemotactic toward nitrate. A model aquifer column was used to evaluate the effects of motility in the presence of groundwater flow, and a second column was used to isolate motility in the absence of flow. Both columns contained CT-saturated sediments and groundwater containing CT and nitrate. The flow column was inoculated near its upstream end with strain KC, base, acetate, and phosphate and flushed continuously thereafter with contaminated groundwater. Cells migrated through the column at a velocity exceeding that of the groundwater, removing both aqueous and sorbed CT. The no-flow column was inoculated near its midpoint and maintained as a static incubation. Motile KC cells migrated over a 0.3 m distance within 5 days, giving a cell velocity of {gt}5 cm/day. Over 94% of the CT in the column was removed in 26 days. The results support the hypothesis that localized depletion of nitrate during denitrification creates nitrate gradients that trigger a chemotactic response. The results also indicate that motile KC cells can degrade CT.

  2. Degradation of carbon tetrachloride in a semi-continuous packed-bed bioreactor

    SciTech Connect

    Levinson, W.E.; Korus, R.A.; Crawford, R.L.

    1995-12-31

    Pseudomonas sp. KC degrades carbon tetrachloride (CT) when grown under iron limited conditions. A packed-bed bioreactor was constructed out of glass and Teflon components and contained glass beads as a packing material. Total void volume of the reactor, including the pump reservoir, was approximately 300 mL. Media was recirculated through the reactor with a Teflon diaphragm pump and contained nitrate as terminal electron acceptor. After inoculation with KC and biofilm growth, the pump reservoir was replaced with fresh media and 3.0 mg/L CT was introduced to the reactor. When the initial CT had been degraded, 10% of the reactor volume was replaced with new media and CT was reintroduced. This process was repeated a second time. The initial degradation rate of the reactor increased from 75 {mu}g CT L{sup -1} hr{sup -1} for the first feeding to 109 {mu}g L{sup -1} hr{sup -1} for the third. A second reactor was packed with a Celite (diatomaceous earth) biocarrier and inoculated in a similar manner to the glass bead reactor. Degradation of CT in this reactor appeared to be suppressed, possibly due to the availability of iron to the bacteria from the biocarrier. While these experiments indicate it should be possible to design a bioreactor utilizing Pseudomonas sp. KC to degrade CT in contaminated water, the suppression of degradative activity by iron will require special precautions to be taken in reactor design.

  3. Simulation and reference interaction site model theory of methanol and carbon tetrachloride mixtures.

    PubMed

    Munaò, G; Costa, D; Saija, F; Caccamo, C

    2010-02-28

    We report molecular dynamics and reference interaction site model (RISM) theory of methanol and carbon tetrachloride mixtures. Our study encompasses the whole concentration range, by including the pure component limits. We majorly focus on an analysis of partial, total, and concentration-concentration structure factors, and examine in detail the k-->0 limits of these functions. Simulation results confirm the tendency of methanol to self-associate with the formation of ring structures in the high dilution regime of this species, in agreement with experimental studies and with previous simulations by other authors. This behavior emerges as strongly related to the high nonideality of the mixture, a quantitative estimate of which is provided in terms of concentration fluctuation correlations, through the structure factors examined. The interaggregate correlation distance is also thereby estimated. Finally, the compressibility of the mixture is found in good agreement with experimental data. The RISM predictions are throughout assessed against simulation; the theory describes better the apolar solvent than the alcohol properties. Self-association of methanol is qualitatively reproduced, though this trend is much less marked in comparison with simulation results.

  4. Protective effects of Cornus mas fruit extract on carbon tetrachloride induced nephrotoxicity in rats

    PubMed Central

    Es.Haghi, M.; Dehghan, G.; Banihabib, N.; Zare, S.; Mikaili, P.; Panahi, F.

    2014-01-01

    Oxidative damage is implicated in the pathogenesis of kidney injury. Cornus mas is used for in renal aliments traditionally in Iran. The present study was aimed to investigate the antioxidant activity of C. mas fruit extract (CMFE) on carbon tetrachloride (CCl4) treated oxidative stress in Wistar albino rats. Forty two male albino rats were divided into seven groups. Group I served as a sham; Group II served as a normal control; Group III served as a toxic control, with CCl4 (1 ml/kg body weight; 80% in olive oil); Groups IV and V received CMFE at doses of 300 and 700 mg/kg before CCl4 injection; Groups VI and VII received extract at same doses orally at 2, 6, 12, 24 and 48 h after CCl4 intoxication. CCl4 injection produced a significant rise in serum markers of oxidative stress and lipid peroxidation product malondialdehyde along with the reduction of antioxidant enzymes such as superoxide dismuta, catalase and glutathion peroxidase. Serum creatinine, urea and uric acid concentrations were increased whereas level of protein and albumin were reduced. Treatment of rats with different doses of fruit extract (300 and 700 mg/kg) significantly (P < 0.05) ameliorated the alterations induced with CCl4 in lipid peroxidation, antioxidant defenses, biochemical and renal lesions. Based on these results, we conclude that CMFE protects kidney from oxidative stress induced by CCl4. PMID:25249718

  5. Protective effects of luteolin-7-glucoside against liver injury caused by carbon tetrachloride in rats.

    PubMed

    Qiusheng, Zheng; Xiling, Sun; Xubo; Meng, Song; Changhai, Wang

    2004-04-01

    Ixeris chinensis (Thunb.) Nakai has been used as a Chinese folk medicine; the information on the physiological and biochemical functions of the compounds extracted from I. chinensis is still scanty. We investigated the effects of luteolin -7-glucoside (LUTG) isolated from I. chinensis against liver injury caused by carbon tetrachloride (CCl4). CCl4 significantly increased the enzyme activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) in blood serum, as well as the level of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in liver tissue, and decreased the levels of reduced glutathione (GSH). Pretreatment with LUTG was not only able to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also reduce the damage of hepatocytes in vitro. On the other hand, we also found LUTG has strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. The hepatoprotective activity of LUTG was possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that LUTG had protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of LUTG may help in the development of a clinical application.

  6. Induction of lipid peroxidation by hexachlorocyclohexane, dieldrin, TCDD, carbon tetrachloride, and hexachlorobenzene in rats

    SciTech Connect

    Goel, M.R.; Shara, M.A.; Stohs, S.J.

    1988-02-01

    Hexachlorobenzene (HCB), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), hexachlorocyclohexane (HCCH) and dieldrin are all halogenated lipophilic environmental contaminants. A common biologic property of these compounds is their ability to induce hepatic microsomal drug metabolizing enzymes. Furthermore, exposure of laboratory animals to these xenobiotics elicits a number of similar effects including porphyria, hypothyroidism, a wasting syndrome and lethality. Perturbation of membrane lipids and lipid peroxidation may be responsible for at least part of the toxic effects of HCCH. TCDD has been shown to induce lipid peroxidation in hepatic and extrahepatic tissues. Based on the similar toxic manifestations of HCB, HCCH, TCDD and dieldrin, the authors have examined the effects of these xenobiotics on hepatic lipid peroxidation following an acutely toxic dose. Lipid peroxidation was assessed by determining the content of thiobarbituric acid reactive substance (TBARS) in the liver, employing malondialdehyde as the standard. Animals were also treated with carbon tetrachloride, a well know inducer of lipid peroxidation, as a positive control. Furthermore, the ability of these xenobiotics to inhibit selenium dependent glutathione peroxidase (GSHPX) activity was determined.

  7. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y. Mauricio; Vrabec, Jadran

    2016-03-01

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values.

  8. Tryptophan-niacin metabolism in liver cirrhosis rat caused by carbon tetrachloride.

    PubMed

    Egashira, Y; Isagawa, A; Komine, T; Yamada, E; Ohta, T; Shibata, K; Sanada, H

    1999-08-01

    We investigated the change of tryptophan-niacin metabolism induced by carbon tetrachloride (CCl4) in rats with liver cirrhosis. The rats were injected with CCl4 (0.5 or 1 mL of 50% olive oil solution/kg body weight) twice a week for 1 or 2 mo and given phenobarbital water simultaneously. The urinary excretions of nicotinamide (Nam) and its metabolites were assayed. As the result, the urinary excretion of Nam, N1-methyl-4-pyridone-3-carboxamide (4-Py), Nam + N1-methylnicotinamide (MNA) + N1-methyl-2-pyridone-5-carboxamide (2-Py) + 4-Py was lower in the CCl4-treated groups than in the non-treated group (control) regardless of the experimental period (1 mo and 2 mo) or dosing amount of CCl4 (0.5 and 1 mL). Moreover, we investigated which pathway of tryptophan-niacin metabolism was affected in CCl4-treated rat. As the result, the possibility that the MNA-->4-Py reaction is inhibited by CCl4 treatment was suggested in this experiment.

  9. Inhibition of poly(ADP-ribose) polymerase-1 attenuates the toxicity of carbon tetrachloride

    PubMed Central

    Banasik, Marek; Stedeford, Todd; Strosznajder, Robert P; Takehashi, Masanori; Tanaka, Seigo; Ueda, Kunihiro

    2011-01-01

    Carbon tetrachloride (CCl4) is routinely used as a model compound for eliciting centrilobular hepatotoxicity. It can be bioactivated to the trichloromethyl radical, which causes extensive lipid peroxidation and ultimately cell death by necrosis. Overactivation of poly(ADP-ribose) polymerase-1 (PARP-1) can rapidly reduce the levels of (β-nicotinamide adenine dinucleotide and adenosine triphosphate and ultimately promote necrosis. The aim of this study was to determine whether inhibition of PARP-1 could decrease CCl4-induced hepatotoxicity, as measured by degree of poly(ADP-ribosyl)ation, serum levels of lactate dehydrogenase (LDH), lipid peroxidation,and oxidative DNA damage. For this purpose, male ICR mice were administered intraperitoneally a hepatotoxic dose of CCl4 with or without 6(5H)-phenanthridinone, a potent inhibitor of PARP-1. Animals treated with CCl4 exhibited extensive poly(ADP-ribosyl)ation in centrilobular hepatocytes, elevated serum levels of LDH, and increased lipid peroxidation. In contrast, animals treated concomitantly with CCl4 and 6(5H)-phenanthridinone showed significantly lower levels of poly(ADP-ribosyl) ation, serum LDH, and lipid peroxidation. No changes were observed in the levels of oxidative DNA damage regardless of treatment. These results demonstrated that the hepatotoxicity of CCl4is dependent on the overactivation of PARP-1 and that inhibition of this enzyme attenuates the hepatotoxicity of CCl4. PMID:21395487

  10. Abiotic Degradation Rates for Carbon Tetrachloride and Chloroform: Progress in FY 2010

    SciTech Connect

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Humphrys, Daniel R.; Wietsma, Thomas W.; Truex, Michael J.

    2010-12-08

    This report documents the progress made through FY 2010 on a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater at the Hanford Site for carbon tetrachloride (CT) and chloroform (CF). The study also explores the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. The research was initiated to decrease the uncertainties in abiotic degradation rates of CT and chloroform CF associated with temperature and possible heterogeneous effects. After 2 years of data collection, the first evidence for heterogeneous effects was identified for hydrolysis of CT, and preliminary evidence for the effects of different mineral types on CF hydrolysis rates also was reported. The CT data showed no difference among mineral types, whereas significant differences were seen in the CF results, perhaps due to the fact that CF hydrolyzes by both neutral and base-catalyzed mechanisms whereas CT follows only the neutral hydrolysis path. In this report, we review the project objectives, organization, and technical approaches taken, update the status and results of the hydrolysis-rate experiments after 4 years of experimentation (i.e., through FY 2010), and provide a brief discussion of how these results add to scientific understanding of the behavior of the CT/CF plume at the Hanford Site.

  11. The protective effect of infliximab against carbon tetrachloride-induced acute lung injury

    PubMed Central

    Kurt, Aysel; Tumkaya, Levent; Yuce, Suleyman; Turut, Hasan; Cure, Medine Cumhur; Sehitoglu, Ibrahim; Kalkan, Yildiray; Pusuroglu, Gokhan; Cure, Erkan

    2016-01-01

    Objective(s): Carbon tetrachloride (CCl4) causes pulmonary toxicity. Infliximab (Ib) is a potent inhibitor of tumor necrosis factor-alpha (TNF-α). We aimed to investigate whether Ib has a protective effect on CCl4 induced lung injury. Materials and Methods: Rats were divided into control, CCl4, and CCl4+Ib groups. A single dose of 2 ml/kg CCI4 was administered to CCI4 group and a single dose of 7 mg/kg Ib was given to CCl4+Ib group 24 hr before applying CCI4. Results: TNF-α, malondialdehyde (MDA), nitric oxide (NO) and caspase-3 levels of the CCl4 group were markedly higher than both the control and CCl4+Ib groups. The CCI4+Ib group had lower histopathological injury than the CCl4 group. Conclusion: Ib as a strong TNF-α blocker decreases the production of proinflammatory cytokines, MDA, and oxidative stress leading to a protective effect against CCl4 induced lung tissue injury. PMID:27482351

  12. Liquiritigenin Protects Rats from Carbon Tetrachloride Induced Hepatic Injury through PGC-1α Pathway

    PubMed Central

    Zhang, Yiping; He, Yuanqiao; Yu, Hongbo; Ma, Fuying; Wu, Jianguo; Zhang, Xiaoyu

    2015-01-01

    The lack of effective treatment for liver cirrhosis and hepatocellular carcinomas imposes serious challenges to the healthcare system. Here, we investigated the efficacy and mechanism of liquiritigenin involved in preventing or retarding the progression of liver diseases in a rat model with chronic carbon tetrachloride (CCl4) exposure. Sprague Dawley rats were given CCl4 and lliquiritigenin alone or simultaneously for 8 weeks before liver was harvested to check histological changes by Hematoxylin and Eosin (H&E) staining, apoptosis by TUNEL assay, ROS by dihydroethidium staining, antioxidant enzyme activities and malondialdehyde using specific kits, and gene expression by quantitative real-time PCR and western blot. Chronic CCl4 exposure caused profound changes in liver histology with extensive hepatocyte death (necrosis and apoptosis), fat accumulation, and infiltration of inflammatory cells, accompanied by depressed activities of antioxidant enzymes, increased oxidative stress, elevated expression of inflammation and fibrotic genes, and downregulation of PGC-1α, ND1, and Bcl-x in rat liver. All these changes were abolished or alleviated by lliquiritigenin. The results demonstrated that liquiritigenin is effective in protecting liver from injury or treating chronic liver diseases. The modulation of PGC-1α and its downstream genes might play a critical role in relieving CCl4-induced hepatic pathogenesis by liquiritigenin. PMID:26199636

  13. Protective effect of boric acid against carbon tetrachloride-induced hepatotoxicity in mice.

    PubMed

    Ince, Sinan; Keles, Hikmet; Erdogan, Metin; Hazman, Omer; Kucukkurt, Ismail

    2012-07-01

    The protective effect of boric acid against liver damage was evaluated by its attenuation of carbon tetrachloride (CCl(4))-induced hepatotoxicity in mice. Male albino mice were treated intraperitoneally (i.p.) with boric acid (50, 100, and 200 mg/kg) or silymarin daily for 7 days and received 0.2% CCl(4) in olive oil (10 mL/kg, i.p.) on day 7. Results showed that administration of boric acid significantly reduced the elevation in serum levels of aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase, and the level of malondialdehyde in the liver that were induced by CCl(4) in mice. Boric acid treatment significantly increased glutathione content, as well as the activities of superoxide dismutase and catalase in the liver. Boric acid treatment improved the catalytic activity of cytochrome P450 2E1 and maintained activation of nuclear factor kappa light-chain enhancer of activated B cell gene expression, with no effect on inducible nitric oxide synthase gene expression in the livers of mice. Histopathologically, clear decreases in the severity of CCl(4)-induced lesions were observed, particularly at high boric acid concentrations. Results suggest that boric acid exhibits potent hepatoprotective effects on CCl(4)-induced liver damage in mice, likely the result of both the increase in antioxidant-defense system activity and the inhibition of lipid peroxidation.

  14. In vitro study of lovastatin interactions with amiodarone and with carbon tetrachloride in isolated rat hepatocytes

    PubMed Central

    Krasteva, AZ; Mitcheva, MK; Kondeva-Burdina, MS; Descatoire, VA

    2007-01-01

    AIM: To investigate the interactions at a metabolic level between lovastatin, amiodarone and carbon tetrachloride in isolated rat hepatocytes. METHODS: For cell isolation two-step collagenase liver perfusion was performed. Lovastatin was administered alone in increasing concentrations (1 μmol/L, 3 μmol/L, 5 μmol/L and 10 μmol/L) and in combination with CCl4 (86 μmol/L). The cells were also pretreated with 14 μmol/L amiodarone and then the other two compounds were added. RESULTS: Lovastatin promoted concentration-dependent significant toxicity estimated by decrease in cell viability and GSH level by 45% and 84%, respectively. LDH-activity increased by 114% and TBARS content by 90%. CCl4 induced the expected severe damage on the examined parameters. CCl4 induced toxicity was attenuated after lovastatin pretreatment, which was expressed in less increased values of LDH activity and TBARS levels, as well as in less decreased cell viability and GSH concentrations. However, the pretreatment of hepatocytes with amiodarone abolished the protective effect of lovastatin. CONCLUSION: We suggest that the observed cytopro-tective effect was due to interactions between lovastatin, CCl4 and amiodarone at a metabolic level. PMID:17465501

  15. Danshensu-mediated protective effect against hepatic fibrosis induced by carbon tetrachloride in rats.

    PubMed

    Qu, W; Huang, H; Li, K; Qin, C

    2014-12-01

    The culprit of hepatic fibrosis (HF) is linked to suprathreshold deposition of collagen. Thus, collagen reduction by improved metabolism contributes to HF management. In this study, we aimed to investigate the hepatoprotective effects of Danshensu (DSS) against carbon tetrachloride (CCl4)-induced HF rats. The results showed that DSS-administrated rats resulted in decreasing in hepatosomatic indexes, and lowering serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Meanwhile, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were increased, while the content of malonaldehyde (MDA) was lessened in liver tissue of DSS administration group. In addition, the pro-fibrotic markers of hydroxyproline (Hyp), type III procollagen (PCIII) and hyaluronic acid (HA) contents were decreased. Histopathological examination confirmed that the hepatotoxicity in CCl4-injured rats was alleviated following the DSS administration. Furthermore, intrahepatic protein expressions of alpha-smooth muscle actin (α-SMA), phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) were effectively down-regulated, respectively. Overall, this work demonstrates that DSS played the protective effect against CCl4-induced cytotoxicity in liver tissue, which the probable mechanism is associated with attenuation of lipid peroxidation, collagen accumulation and enhancement of anti-oxidative defense capability, as well as regulation of intrahepatic JAK/STAT pathway for maintaining collagenic homoeostasis. PMID:25201143

  16. Evaluation of the spontaneous reversibility of carbon tetrachloride-induced liver cirrhosis in rabbits.

    PubMed

    Bravo, E; D'Amore, E; Ciaffoni, F; Mammola, C L

    2012-04-01

    There is a general consensus that liver fibrosis in humans is potentially reversible, while scepticism prevails on the concept that cirrhosis can be truly reversed. The availability of suitable experimental models is fundamental for disease research. The experimental murine model of liver cirrhosis induced by carbon tetrachloride (CCl(4)) reproduces both the histological picture of the postnecrotic cirrhosis and its biochemical and clinical parameters. Normal hepatic structure is modified by formation of regeneration nodules. Fibrosis represents a morphological element of disease and an effect of hepatocyte necrosis. However, the relevance for research of this well-established model of liver cirrhosis is hampered by some spontaneous cirrhosis regression reported in mice and rats. It has been reported that CCl(4) also induces experimental liver cirrhosis in rabbits, but it is not known whether the process is reversible in this species. The aim of our study was to investigate this question. Male New Zealand White rabbits were treated intragastrically with CCl(4) or the vehicle only for 19 weeks and groups were sacrificed three and five months after treatment interruption. Cirrhotic and control livers were processed for routine light microscopy and for morphometric study of fibrosis by semiquantitative evaluation. The degree of fibrosis was based on the Knodell's scoring system.

  17. Nanoparticle Based Delivery of Quercetin for the Treatment of Carbon Tetrachloride Mediated Liver Cirrhosis in Rats.

    PubMed

    Verma, Shashi Kant; Rastogil, Shweta; Arora, Indu; Javed, Kalim; Akhtar, Mohd; Samim, Mohd

    2016-02-01

    Liver fibrosis is the common response to chronic liver injury and ultimately leads to cirrhosis. There is a pressing need in the pharmaceutical industry to develop efficient well-targeted drug delivery systems, which are lacking to date. This study was designed to investigate the efficacy of a nanoquercetin NQ; i.e., quercetin encapsulated in PAG (p-aminophenyl-1-thio-β-D-galactopryranoside)-coated NIPAAM (N-isopropyl acrylamide) nanopolymer in liver compared with naked quercetin (Q) using a carbon tetrachloride (CCl₄)-mediated liver cirrhosis model. NQ was more effective at restoring liver membrane integrity as indicated by significantly reduced serum markers, including Alanine Transaminase (ALT), Aspartate Aminotransferase (AST), Alkaline Phosphatase (ALP) and Lactate Dehydrogenase (LDH), compared with naked Q. The findings of reduced collagen and histopathology also show that the NQ effects were much better than those of naked Q. Biochemical parameters, including antioxidant defense enzymes, also provide supporting evidence. Furthermore, the decrease in NF-κB and NOS-2 expression in the NQ-treated groups was also much stronger than in the naked Q-treated group. Thus, the data clearly suggest that NQ not only provides significant hepatoprotection compared with naked Q, but it also substantially lowered the required concentration (1,000 to 10,000-fold lower) by increasing the bioavailability.

  18. Protection Effect of Kallistatin on Carbon Tetrachloride-Induced Liver Fibrosis in Rats via Antioxidative Stress

    PubMed Central

    Huang, Xiaoping; Wang, Xiao; Lv, Yinghui; Xu, Luli; Lin, Junsheng; Diao, Yong

    2014-01-01

    Prolonged inflammation and oxidative stress are emerging as key causes of pathological wound healing and the development of liver fibrosis. We have investigated the effects of recombinant human kallistatin, produced in Pichia. pastoris, on preventing carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Daily administration of kallistatin prevented development of CCl4-induced liver fibrosis, which was evidenced by histological study. In all kallistatin treated rats, activation of hepatic stellate cells (HSC) as assessed by s-smooth muscle actin staining was attenuated, TGF- β1 expression was inhibited, class I serum biomarkers associated with the process of fibrogenesis, such as hyaluronic acid, laminin, and procollagen III, were lowered, compared with that in the model control group. Furthermore, residual hepatic functional reserve was improved by kallistatin treatment. CCl4 induced elevation of malondialdehyde level and reduced superoxide dismutase activity in the liver, while kallistatin reduced these oxidative parameters. We also investigated the effects of kallistatin on rat primary HSC and LX-2, the human HSC cell line. Kallistatin scavenged H2O2-induced ROS in the LX-2 cells, and suppressed the activation of primary HSC. These results suggest recombinant human kallistatin might be a promising drug candidate for therapeutic intervention of liver fibrosis. PMID:24558397

  19. Polysaccharides from Angelica and Astragalus exert hepatoprotective effects against carbon-tetrachloride-induced intoxication in mice.

    PubMed

    Pu, Xiuying; Fan, Wenbo; Yu, Shuang; Li, Yan; Ma, Xiaolong; Liu, Lu; Ren, Jing; Zhang, Weijie

    2015-01-01

    This study aimed to investigate the effects of polysaccharide from Angelica and Astragalus (AAP) on carbon tetrachloride (CCl4) induced liver damage in mice. A total of 120 Kunming mice were randomly distributed among 6 groups comprising (i) the normal control mice, (ii) the CCl4 treatment group, (iii) the bifendate treatment group, (iv) the AAP treatment group, (v) the Angelica sinensis polysaccharide (ASP) treatment group, and (vi) the Astragalus membranaceus polysaccharide (AMP) treatment group. AAP, ASP and AMP were administered to mice treated with CCl4. The activities of alanine transaminase (ALT) and aspartate transaminase (AST) in the serum, and superoxide dismutase (SOD) and malondialdehyde (MDA) in the liver tissues were quantified, as well as the liver index. Hepatic histological changes were observed by staining liver sections with hematoxylin and eosin. Our results show that bifendate, AAP, ASP, and AMP significantly decreased the activities of MDA, AST, and ALT, and enhanced the activity of SOD in CCl4-treated mice. Bifendate, AAP, ASP, and AMP consistently ameliorated the liver injuries induced with CCl4. Notably, the hepatoprotective effect of AAP was stronger than that of bifendate, ASP, or AMP. In addition, AAP alleviated liver inflammation and decreased the liver indexes of mice induced with CCl4. These effects were at least partly due to the antioxidant properties of AAP in scavenging free radicals to ameliorate oxidative stress and to inhibit lipid peroxidation.

  20. Hepatoprotective effect of pinoresinol on carbon tetrachloride-induced hepatic damage in mice.

    PubMed

    Kim, Hyo-Yeon; Kim, Joon-Ki; Choi, Jun-Ho; Jung, Joo-Yeon; Oh, Woo-Yong; Kim, Dong Chun; Lee, Hee Sang; Kim, Yeong Shik; Kang, Sam Sik; Lee, Seung-Ho; Lee, Sun-Mee

    2010-01-01

    Forsythiae Fructus is known to have diuretic, anti-bacterial, and anti-inflammatory activities. This study examined the hepatoprotective effects of pinoresinol, a lignan isolated from Forsythiae Fructus, against carbon tetrachloride (CCl(4))-induced liver injury. Mice were treated intraperitoneally with vehicle or pinoresinol (25, 50, 100, and 200 mg/kg) 30 min before and 2 h after CCl4 (20 microl/kg) injection. In the vehicle-treated CCl(4 )group, serum aminotransferase activities were significantly increased 24 h after CCl4 injection, and these increases were attenuated by pinoresinol at all doses. Hepatic glutathione contents were significantly decreased and lipid peroxidation was increased after CCl4 treatment. These changes were attenuated by 50 and 100 mg/kg of pinoresinol. The levels of protein and mRNA expression of inflammatory mediators, including tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2, were significantly increased after CCl4 injection; and these increases were attenuated by pinoresinol. Nuclear translocation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of c-Jun, one of the components of activating protein 1 (AP-1), were inhibited by pinoresinol. Our results suggest that pinoresinol ameliorates CCl4)-induced acute liver injury, and this protection is likely due to anti-oxidative activity and down-regulation of inflammatory mediators through inhibition of NF-kappaB and AP-1.

  1. Protective effects of luteolin-7-glucoside against liver injury caused by carbon tetrachloride in rats.

    PubMed

    Qiusheng, Zheng; Xiling, Sun; Xubo; Meng, Song; Changhai, Wang

    2004-04-01

    Ixeris chinensis (Thunb.) Nakai has been used as a Chinese folk medicine; the information on the physiological and biochemical functions of the compounds extracted from I. chinensis is still scanty. We investigated the effects of luteolin -7-glucoside (LUTG) isolated from I. chinensis against liver injury caused by carbon tetrachloride (CCl4). CCl4 significantly increased the enzyme activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) in blood serum, as well as the level of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in liver tissue, and decreased the levels of reduced glutathione (GSH). Pretreatment with LUTG was not only able to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also reduce the damage of hepatocytes in vitro. On the other hand, we also found LUTG has strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. The hepatoprotective activity of LUTG was possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that LUTG had protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of LUTG may help in the development of a clinical application. PMID:15125574

  2. Efficient amelioration of carbon tetrachloride induced toxicity in isolated rat hepatocytes by Syzygium cumini Skeels extract.

    PubMed

    Veigas, Jyothi M; Shrivasthava, Richa; Neelwarne, Bhagyalakshmi

    2008-09-01

    Syzygium cumini, Indian black plum or Java plum, is a rich source for anthocyanins (230 mg/100g DW) showing high antioxidant activity in vitro. In the following study it is further demonstrated that S. cumini peel extract rich in anthocyanins (SCA) offers considerable protection against carbon tetrachloride (CCl(4))-induced damage in rat hepatocytes. SCA itself being non-toxic to primary rat hepatocytes at concentrations ranging from 50 to 500 ppm, was found to suppress CCl(4)-induced LDH leakage by 54% at 50ppm, thereby improving the cell viability by 39%. The SCA significantly reversed the CCl(4) induced changes in cellular glutathione (GSH) level, lipid peroxidation and activity of the antioxidant enzyme glutathione peroxidase. Exposure of hepatocytes to SCA after CCl(4) treatment was found to elevate GSH and GPx activities by 2-folds, whereas the activities of catalase and superoxide dismutase were not significantly affected. The fruit pulp extract (SPE) was less effective in offering protection to rat hepatocytes, particularly in terms of total GSH content and a consequent increase in lipid peroxidation although the higher GPx activity suggests the probable involvement of GSH as a substrate for GPx. These observations suggest that the fruit peel extract of S. cumini, is largely responsible for the reversal of CCl(4)-induced oxidative damage in rat hepatocytes. Both peel and pulp extract appear to offer protection to rat hepatocytes through GPx along with other biological pathways independent of catalase and superoxide dismutase. PMID:18538978

  3. Simultaneous biodegradation of carbon tetrachloride and trichloroethylene in a coupled anaerobic/aerobic biobarrier.

    PubMed

    Kwon, Kiwook; Shim, Hojae; Bae, Wookeun; Oh, Juhyun; Bae, Jisu

    2016-08-01

    Simultaneous biodegradation of carbon tetrachloride (CT) and trichloroethylene (TCE) in a biobarrier with polyethylene glycol (PEG) carriers was studied. Toluene/methanol and hydrogen peroxide (H2O2) were used as electron donors and an electron acceptor source, respectively, in order to develop a biologically active zone. The average removal efficiencies for TCE and toluene were over 99.3%, leaving the respective residual concentrations of ∼12 and ∼57μg/L, which are below or close to the groundwater quality standards. The removal efficiency for CT was ∼98.1%, with its residual concentration (65.8μg/L) slightly over the standards. TCE was aerobically cometabolized with toluene as substrate while CT was anaerobically dechlorinated in the presence of electron donors, with the respective stoichiometric amount of chloride released. The oxygen supply at equivalent to 50% chemical oxygen demand of the injected electron donors supported successful toluene oxidation and also allowed local anaerobic environments for CT reduction. The originally augmented (immobilized in PEG carriers) aerobic microbes were gradually outcompeted in obtaining substrate and oxygen. Instead, newly developed biofilms originated from indigenous microbes in soil adapted to the coupled anaerobic/aerobic environment in the carrier for the simultaneous and almost complete removal of CT, TCE, and toluene. The declined removal rates when temperature fell from 28 to 18°C were recovered by doubling the retention time (7.2 days). PMID:27054665

  4. Betanin attenuates carbon tetrachloride (CCl4)-induced liver injury in common carp (Cyprinus carpio L.).

    PubMed

    Han, Junyan; Gao, Cheng; Yang, Shaobin; Wang, Jun; Tan, Dehong

    2014-06-01

    This study investigates the protective effect of betanin against liver injury induced by carbon tetrachloride (CCl4) in common carp (Cyprinus carpio L.). The fish were treated with 1, 2, and 4 % betanin in fodder throughout the experiment. After 20 days of treatment, the fish were intraperitoneally injected with 20 % (v/v in peanut oil) CCl4 at a volume of 0.5 mL/kg body weight. The fish were killed 3 days after CCl4 intoxication, and then, histological and biochemical assays were performed. Results showed that CCl4-induced liver CYP2E1 activity, oxidative stress, and injury, as indicated by the depleted glycogen storage, increased serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT) activities and liver histological damage. Compared with the CCl4 control group, the betanin-treated groups exhibited reduced CYP2E1 activity, decreased malondialdehyde level, increased liver antioxidative capacity (increased glutathione level and superoxide dismutase and catalase activities), increased liver glycogen storage, and reduced serum AST/ALT activities, with significant differences in the 2 and 4 % groups (p < 0.05). Histological assay further confirmed the protective effect of betanin. In conclusion, betanin attenuates CCl4-induced liver damage in common carp. Moreover, the inhibition of CYP2E1 activity and oxidative stress may have significant roles in the protective effect of betanin.

  5. Sida rhombifolia ssp. retusa seed extract inhibits DEN induced murine hepatic preneoplasia and carbon tetrachloride hepatotoxicity.

    PubMed

    Poojari, Radhika; Gupta, Sanjay; Maru, Girish; Khade, Bharat; Bhagwat, Sanjay

    2009-01-01

    Sida rhombifolia ssp. retusa is a well established drug in the Ayurvedic system of medicine used for antirheumatism and antiasthmatism. Inhibitory effects of S. rhombifolia ssp. retusa seed extract on DEN induced hepatocellular preneoplastic foci and carbon tetrachloride (CCl4) induced hepatotoxicity was investigated in rats. Rats received DEN, 1ppm/g b.w. in drinking water for 6 weeks or CCl(4), 0.7 ml/kg i.p. once a week for 4 weeks and seed extract 50 mg, 100 mg/kg b.w. orally prior, during and after exposure to DEN/CCl4 for 20 or 5 weeks, respectively. Treatment with seed extract significantly inhibited the increase in DEN/CCl(4) induced activities of pre-cancerous marker enzymes; gamma-glutamyl transpeptidase, glutathione-S-transferase, hepatotoxicity marker enzymes; glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and alkaline phosphatase as well as lipid peroxidase. Depleted glutathione, protein and albumin levels were restored. Also, histopathological and transmission electron microscopic studies showed prevention of cellular degenerative changes. The chemopreventive and hepatoprotective potentials of seed extract are due to free radical scavenging activity and restoration of cellular structural integrity.

  6. Hepatocurative potential of sesquiterpene lactones of Taraxacum officinale on carbon tetrachloride induced liver toxicity in mice.

    PubMed

    Mahesh, A; Jeyachandran, R; Cindrella, L; Thangadurai, D; Veerapur, V P; Muralidhara Rao, D

    2010-06-01

    The hepatocurative potential of ethanolic extract (ETO) and sesquiterpene lactones enriched fraction (SL) of Taraxacum officinale roots was evaluated against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in mice. The diagnostic markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin contents were significantly elevated, whereas significant reduction in the level of reduced glutathione (GSH) and enhanced hepatic lipid peroxidation, liver weight and liver protein were observed in CCl 4 induced hepatotoxicity in mice. Post-treatment with ETO and SL significantly protected the hepatotoxicity as evident from the lower levels of hepatic enzyme markers, such as serum transaminase (ALT, AST), ALP and total bilirubin. Further, significant reduction in the liver weight and liver protein in drug-treated hepatotoxic mice and also reduced oxidative stress by increasing reduced glutathione content and decreasing lipid peroxidation level has been noticed. The histopathological evaluation of the liver also revealed that ETO and SL reduced the incidence of liver lesions induced by CCl 4 . The results indicate that sesquiterpene lactones have a protective effect against acute hepatotoxicity induced by the administration of CCl 4 in mice. Furthermore, observed activity of SL may be due to the synergistic action of two sesquiterpene lactones identified from enriched ethyl acetate fraction by HPLC method.

  7. Integrating phytoremediation, wetlands, spray irrigation, and prairie restoration to treat carbon tetrachloride contamination in a rural community.

    SciTech Connect

    LaFreniere, L. M.; Negri, M. C.; Sedivy, R. A.; Yan, Y.E.; Steck, D.; Gilmore, S. M.; Kulakow, P.; Hutchinson, S.; Erickson, L.; USDA; Kansas State Univ.

    2006-01-01

    In a cooperative conservation effort, the U.S. Department of Agriculture is cleaning up a contaminated aquifer in a rural community and simultaneously improving the community's recreational and educational opportunities. While one component of the cleanup system irrigates school athletic fields that were parched and bare in previous summers, other components have created a nearby public recreational area. The USDA's other partners in this effort are the U.S. Department of Energy's Argonne National Laboratory (ANL) and the U.S. Environmental Protection Agency, Kansas State University, state regulators, local businesses, governmental units, and residents. The groundwater aquifer beneath Murdock, Nebraska, became contaminated with carbon tetrachloride as the result of fumigation of grain stored decades ago in a USDA facility. Contaminant levels in the groundwater (up to 7,800 {micro}g/L at one time) precluded use of the aquifer for drinking water, and discharge of contaminated groundwater to a nearby creek posed health risks. Concentrations of carbon tetrachloride as high as 361 {micro}g/kg in subsurface soil indicated the presence of a soil source. Model simulations of potential leaching indicated that the source would continue to release contaminant for at least 80 years, and migration to the creek would continue after that. The USDA, ANL, and EPA developed an innovative cleanup system that combines multiple technologies. Near the contamination source, pumps extract contaminated groundwater and pass it through a spray irrigation system that dissipates the carbon tetrachloride harmlessly into the air. The treated water irrigates the school's athletic field, nurturing a healthy grassy surface. Supplementing the spray irrigation technology are more than 2,000 trees planted downstream from where the groundwater enters the creek. The trees accomplish phytoremediation by taking up contaminated water and breaking down carbon tetrachloride naturally. Native prairie plants

  8. Enhanced biotransformation of carbon tetrachloride by Acetobacterium woodii upon addition of hydroxocobalamin and fructose

    SciTech Connect

    Hashsham, S.A.; Freedman, D.L.

    1999-10-01

    The objective of this study was to evaluate the effect of hydroxocobalamin (OH-Cbl) on transformation of high concentrations of carbon tetrachloride (CT) by Acetobacterium woodii. Complete transformation of 470 {micro}M CT was achieved by A. woodii within 2.5 days, when 10 {micro}M OH-Cbl was added along with 25.2 mM fructose. This was approximately 30 times faster than A. woodii cultures and medium that did not receive OH-Cbl and 5 times faster than those controls that did receive OH-Cbl, but either live A. woodii or fructose was missing. CT transformation in treatments with only OH-Cbl was indicative of the important contribution of nonenzymatic reactions. Besides increasing the rate of CT transformation, addition of fructose and OH-Cbl to live cultures increased the percentage of [{sup 14}C]CT transformed to {sup 14}CO{sub 2} and {sup 14}C-labeled soluble materials, while decreasing the percentage of CT reduced to chloroform and abiotically transformed to carbon disulfide. {sup 14}CS{sub 2} represented more than 35% of the [{sup 14}C]CT in the presence of reduced medium and OH-Cbl. Conversion of CT to CO was a predominant pathway in formation of CO{sub 2} in the presence of live cells and added fructose and OH-Cbl. These results indicate that the rate and distribution of products during cometabolic transformation of CT by A. woodii can be improved by the addition of fructose and OH-Cbl.

  9. Effect of methanol extract of Dicranopteris linearis against carbon tetrachloride- induced acute liver injury in rats

    PubMed Central

    2014-01-01

    Background Dicranopteris linearis (family Gleicheniaceae) has been reported to possess anti-inflammatory and antioxidant activities but no attempt has been made to study its hepatoprotective potential. The aim of the present study was to determine the hepatoprotective effect of methanol extracts of D. linearis (MEDL) against carbon tetrachloride (CCl4)-induced acute liver injury in rats. Methods 6 groups (n = 6) of rats received oral test solutions: 10% dimethyl sulfoxide (DMSO), 200 mg/kg silymarin, or MEDL (50, 250, and 500 mg/kg), once daily for 7 consecutive days, followed by hepatotoxicity induction with CCl4. Blood and liver were collected for biochemical and microscopic analysis. The extract was also subjected to antioxidant studies (e.g. 2, 2-diphenyl-1-picrylhydrazyl (DPPH)- and superoxide anion-radical scavenging assays, oxygen radical absorbance capacity (ORAC) test and total phenolic content (TPC) determination), phytochemical screening and HPLC analysis. Results Pretreatment with MEDL and silymarin significantly (P < 0.05) reduced the serum levels of AST, ALT and ALP, which were increased significantly (P < 0.05) in DMSO-pretreated group following treatment with CCl4. Histological analysis of liver tissues in groups pretreated with MEDL and silymarin showed mild necrosis and inflammation of the hepatocytes compared to the DMSO-pretreated group (negative control group). The MEDL showed higher DPPH- and superoxide anion-radical scavenging activity as well as high TPC and ORAC values indicating high antioxidant activity. Conclusions MEDL exerts hepatoprotective activity that could be partly contributed by its antioxidant activity and high phenolic content, and hence demands further investigation. PMID:24708543

  10. Melatonin inhibits autophagy and endoplasmic reticulum stress in mice with carbon tetrachloride-induced fibrosis.

    PubMed

    San-Miguel, Beatriz; Crespo, Irene; Sánchez, Diana I; González-Fernández, Bárbara; Ortiz de Urbina, Juan J; Tuñón, María J; González-Gallego, Javier

    2015-09-01

    This study aimed to investigate whether inhibition of autophagy and endoplasmic reticulum (ER stress) associates with the antifibrogenic effect of melatonin in mice treated with carbon tetrachloride (CCl4 ). Mice received CCl4 5 μL/g body wt i.p. twice a week for 4 wk or 6 wk. Melatonin was given at 5 or 10 mg/kg/day i.p, beginning 2 wk after the start of CCl4 administration. Treatment with CCl4 resulted in fibrosis evidenced by the staining of α-smooth muscle actin (α-SMA)-positive cells. CCl4 induced an autophagic response measured as the presence of autophagic vesicles, protein 1 light chain 3 (LC3) staining, conversion of LC3-I to autophagosome-associated LC3-II, changes in expression of beclin-1, UV radiation resistance-associated gene (UVRAG), ubiquitin-like autophagy-related (Atg5), Atg12, Atg16L1, sequestosome 1 (p62/SQSTM1), and lysosome-associated membrane protein (LAMP)-2, and increased phosphorylation of the mammalian target of rapamycin (mTOR). There was an increase in the expression of the ER stress chaperones CCAAT/enhancer-binding protein homologous protein (CHOP), immunoglobulin-heavy-chain-binding protein (BiP/GRP78), and 94-kDa glucose-regulated protein (GRP94), and in the mRNA levels of pancreatic ER kinase (PERK), activating transcription factor 6 (ATF6), ATF4, inositol-requiring enzyme 1 (IRE1), and spliced X-box-binding protein-1 (XBP1). Phospho-IRE1, ATF6, and phospho-PERK protein concentration also increased significantly. Immunohistochemical staining of α-SMA indicated an abrogation of hepatic stellate cells activation by melatonin. Furthermore, treatment with the indole resulted in significant inhibition of the autophagic flux and the unfolded protein response. Findings from this study give new insight into molecular pathways accounting for the protective effect of melatonin in fibrogenesis.

  11. A comprehensive estimate for loss of atmospheric carbon tetrachloride (CCl4) to the ocean

    NASA Astrophysics Data System (ADS)

    Butler, James H.; Yvon-Lewis, Shari A.; Lobert, Jurgen M.; King, Daniel B.; Montzka, Stephen A.; Bullister, John L.; Koropalov, Valentin; Elkins, James W.; Hall, Bradley D.; Hu, Lei; Liu, Yina

    2016-09-01

    Extensive undersaturations of carbon tetrachloride (CCl4) in Pacific, Atlantic, and Southern Ocean surface waters indicate that atmospheric CCl4 is consumed in large amounts by the ocean. Observations made on 16 research cruises between 1987 and 2010, ranging in latitude from 60° N to 77° S, show that negative saturations extend over most of the surface ocean. Corrected for physical effects associated with radiative heat flux, mixing, and air injection, these anomalies were commonly on the order of -5 to -10 %, with no clear relationship to temperature, productivity, or other gross surface water characteristics other than being more negative in association with upwelling. The atmospheric flux required to sustain these undersaturations is 12.4 (9.4-15.4) Gg yr-1, a loss rate implying a partial atmospheric lifetime with respect to the oceanic loss of 183 (147-241) yr and that ˜ 18 (14-22) % of atmospheric CCl4 is lost to the ocean. Although CCl4 hydrolyzes in seawater, published hydrolysis rates for this gas are too slow to support such large undersaturations, given our current understanding of air-sea gas exchange rates. The even larger undersaturations in intermediate depth waters associated with reduced oxygen levels, observed in this study and by other investigators, strongly suggest that CCl4 is ubiquitously consumed at mid-depth, presumably by microbiota. Although this subsurface sink creates a gradient that drives a downward flux of CCl4, the gradient alone is not sufficient to explain the observed surface undersaturations. Since known chemical losses are likewise insufficient to sustain the observed undersaturations, this suggests a possible biological sink for CCl4 in surface or near-surface waters of the ocean. The total atmospheric lifetime for CCl4, based on these results and the most recent studies of soil uptake and loss in the stratosphere is now 32 (26-43) yr.

  12. Degradation and Fate of Carbon Tetrachloride in Unadapted Methanogenic Granular Sludge

    PubMed Central

    Van Eekert, Miriam H. A.; Schröder, Thomas J.; Stams, Alfons J. M.; Schraa, Gosse; Field, Jim A.

    1998-01-01

    The potential of granular sludge from upflow anaerobic sludge blanket (UASB) reactors for bioremediation of chlorinated pollutants was evaluated by using carbon tetrachloride (CT) as a model compound. Granular sludges cultivated in UASB reactors on methanol, a volatile fatty acid mixture, or sucrose readily degraded CT supplied at a concentration of 1,500 nmol/batch (approximately 10 μM) without any prior exposure to organohalogens. The maximum degradation rate was 1.9 μmol of CT g of volatile suspended solids−1 day−1. The main end products of CT degradation were CO2 and Cl−, and the yields of these end products were 44 and 68%, respectively, of the initial amounts of [14C]CT and CT-Cl. Lower chlorinated methanes accumulated in minor amounts temporarily. Autoclaved (dead) sludges were capable of degrading CT at rates two- to threefold lower than those for living sludges, indicating that abiotic processes (mediated by cofactors or other sludge components) played an important role in the degradation observed. Reduced components in the autoclaved sludge were vital for CT degradation. A major part (51%) of the CT was converted abiotically to CS2. The amount of CO2 produced (23%) was lower and the amount of Cl− produced (86%) was slightly higher with autoclaved sludge than with living sludge. Both living and autoclaved sludges could degrade chloroform. However, only living sludge degraded dichloromethane and methylchloride. These results indicate that reductive dehalogenation, which was mediated better by living sludge than by autoclaved sludge, is only a minor pathway for CT degradation. The main pathway involves substitutive and oxidative dechlorination reactions that lead to the formation of CO2. Granular sludge, therefore, has outstanding potential for gratuitous dechlorination of CT to safe end products. PMID:9647798

  13. Degradation and Fate of Carbon Tetrachloride in Unadapted Methanogenic Granular Sludge.

    PubMed

    Van Eekert MHA; Schröder; Stams; Schraa; Field

    1998-07-01

    The potential of granular sludge from upflow anaerobic sludge blanket (UASB) reactors for bioremediation of chlorinated pollutants was evaluated by using carbon tetrachloride (CT) as a model compound. Granular sludges cultivated in UASB reactors on methanol, a volatile fatty acid mixture, or sucrose readily degraded CT supplied at a concentration of 1,500 nmol/batch (approximately 10 µM) without any prior exposure to organohalogens. The maximum degradation rate was 1.9 µmol of CT g of volatile suspended solids-1 day-1. The main end products of CT degradation were CO2 and Cl-, and the yields of these end products were 44 and 68%, respectively, of the initial amounts of [14C]CT and CT-Cl. Lower chlorinated methanes accumulated in minor amounts temporarily. Autoclaved (dead) sludges were capable of degrading CT at rates two- to threefold lower than those for living sludges, indicating that abiotic processes (mediated by cofactors or other sludge components) played an important role in the degradation observed. Reduced components in the autoclaved sludge were vital for CT degradation. A major part (51%) of the CT was converted abiotically to CS2. The amount of CO2 produced (23%) was lower and the amount of Cl- produced (86%) was slightly higher with autoclaved sludge than with living sludge. Both living and autoclaved sludges could degrade chloroform. However, only living sludge degraded dichloromethane and methylchloride. These results indicate that reductive dehalogenation, which was mediated better by living sludge than by autoclaved sludge, is only a minor pathway for CT degradation. The main pathway involves substitutive and oxidative dechlorination reactions that lead to the formation of CO2. Granular sludge, therefore, has outstanding potential for gratuitous dechlorination of CT to safe end products.

  14. Degradation and fate of carbon tetrachloride in unadapted methanogenic granular sludge

    SciTech Connect

    Van Eekert, M.H.A.; Schroeder, T.J.; Stams, A.J.M.; Schraa, G.; Field, J.A.

    1998-07-01

    The potential of granular sludge from upflow anaerobic sludge blanket (UASB) reactors for bioremediation of chlorinated pollutants was evaluated by using carbon tetrachloride (CT) as a model compound. Granular sludges cultivated in UASB reactors on methanol, a volatile fatty acid mixture, or sucrose readily degraded CT supplied at a concentration of 1,500 nmol/batch without any prior exposure to organohalogens. The maximum degradation rate was 1.9 {micro}mol of CT g of volatile suspended solids{sup {minus}1} day{sup {minus}1}. The main end products of CT degradation were CO{sub 2} and Cl{sup {minus}}, and the yields of these end products were 44 and 68%, respectively, of the initial amounts of [{sup 14}C]CT and CT-Cl. Lower chlorinated methanes accumulated in minor amounts temporarily. Autoclaved (dead) sludges were capable of degrading CT at rates two- to threefold lower than those for living sludges, indicating that abiotic processes played an important role in the degradation observed. Reduced components in the autoclaved sludge were vital for CT degradation. A major part (51%) of the CT was converted abiotically to CS{sub 2}. The amount of CO{sub 2} produced was lower and the amount of Cl{sup {minus}} produced was slightly higher with autoclaved sludge than with living sludge. Both living and autoclaved sludges could degrade chloroform. However, only living sludge degraded dichloromethane and methylchloride. These results indicate that reductive dehalogenation, which was mediated better by living sludge than by autoclaved sludge, is only a minor pathway for CT degradation. The main pathway involves substitutive and oxidative dechlorination reactions that lead to the formation of CO{sub 2}. Granular sludge, therefore, has outstanding potential for gratuitous dechlorination of CT to safe end products.

  15. Hepatoprotective effect of Rosa canina fruit extract against carbon tetrachloride induced hepatotoxicity in rat

    PubMed Central

    Sadeghi, Heibatollah; Hosseinzadeh, Saleh; Akbartabar Touri, Mehdi; Ghavamzadeh, Mehdi; Jafari Barmak, Mehrzad; sayahi, Moslem; Sadeghi, Hossein

    2016-01-01

    Objective: The present study was conducted to investigate the hepatoprotective activity of hydro-ethanolic fruit extract of Rosa canina (R. canina) against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Materials and Methods: Male Wistar albino rats were randomly divided into six groups of 8 animals of each, including control, toxic (CCl4), R. canina 250, 500, and 750 mg/kg + CCl4 and R. canina 750 mg/kg alone. R. canina (p.o., daily) and CCl4 (1 ml/kg twice a week, 50% v/v in olive oil, i.p.) were administered to animals for six weeks. Serum analysis was performed to assay the levels of aspartate aminotransferase (AST), alanine amino transaminase (ALT), alkaline phosphatase (ALP), albumin (ALB), total protein (TP) and malondialdehyde (MDA). Biochemical observations were also supplemented with histopathological examination (haematoxylin and eosin staining) of liver section. Results: Hepatotoxicity was evidenced by considerable increase in serum levels of AST, ALT, ALP, and lipid peroxidation (MDA) and decrease in levels of ALB and TP. Injection of CCL4 also induced congestion in central vein, and lymphocyte infiltration. Treatment with hydro-alcoholic fruit extract of R. canina at doses of 500 and 750 mg/kg significantly reduced CCl4-elevated levels of ALT, AST, ALP and MDA (p<0.01). The extract also increased the serum levels of ALB and TP compared to CCl4 group (p<0.01) at the indicated dose Histopathological studies supported the biochemical finding. Conclusion: Our finding indicated hepatoprotective effects of the hydro-alcoholic fruit extract of R. canina on CCl4-induced hepatic damage in rats and suggested that these effects may be produced through reducing oxidative stress. PMID:27222831

  16. A Historical Perspective on Primary and Possible Secondary Sources of Atmospheric Carbon Tetrachloride

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.

    2015-01-01

    Atmospheric sources of Carbon Tetrachloride (CTC) have been controversial since its detection in the early 1970. Initial proposals were that it is globally uniformly distributed and its lack of current emissions and inferred lifetime indicated that it was likely of natural origin. Historical analysis of CTC use and emissions showed that atmospheric CTC was long-lived and mainly of man-made origin although small natural sources and sinks (e. g. oceans) could not be ruled out. This deduction was hard because a majority of emissions had occurred in early part of the 20th century when CTC was commonly used as a fumigant, a solvent, and a raw material for the manufacture of many chemicals. In the 1940's adverse health effects of exposure to CTC became evident and its emissions were greatly curtailed and substituted with C2Cl4 which was thought to be much safer. There were smog chamber studies that showed that C2Cl4, a widely used solvent during the late 20th century, could produce CTC with up to a 7% yield. Subsequently it was discovered that this chemistry probably required Cl atoms and since Cl atoms were not abundant in the atmosphere actual yields based on OH oxidation were probably closer to 0.1%. CTC was subsequently banned by the Montreal Protocol to prevent stratospheric ozone depletion and its preferred substitute C2Cl4 was also banned by EPA for reasons of potential carcinogenicity and toxicity. CTC since has been measured in many airborne NASA campaigns in which plumes have been sampled from a variety of regions which may still be emitting CTC. I will briefly discuss this historical perspective of CTC and show some recent data that may shed light on its current sources or lack there off.

  17. Degradation and Fate of Carbon Tetrachloride in Unadapted Methanogenic Granular Sludge.

    PubMed

    Van Eekert MHA; Schröder; Stams; Schraa; Field

    1998-07-01

    The potential of granular sludge from upflow anaerobic sludge blanket (UASB) reactors for bioremediation of chlorinated pollutants was evaluated by using carbon tetrachloride (CT) as a model compound. Granular sludges cultivated in UASB reactors on methanol, a volatile fatty acid mixture, or sucrose readily degraded CT supplied at a concentration of 1,500 nmol/batch (approximately 10 µM) without any prior exposure to organohalogens. The maximum degradation rate was 1.9 µmol of CT g of volatile suspended solids-1 day-1. The main end products of CT degradation were CO2 and Cl-, and the yields of these end products were 44 and 68%, respectively, of the initial amounts of [14C]CT and CT-Cl. Lower chlorinated methanes accumulated in minor amounts temporarily. Autoclaved (dead) sludges were capable of degrading CT at rates two- to threefold lower than those for living sludges, indicating that abiotic processes (mediated by cofactors or other sludge components) played an important role in the degradation observed. Reduced components in the autoclaved sludge were vital for CT degradation. A major part (51%) of the CT was converted abiotically to CS2. The amount of CO2 produced (23%) was lower and the amount of Cl- produced (86%) was slightly higher with autoclaved sludge than with living sludge. Both living and autoclaved sludges could degrade chloroform. However, only living sludge degraded dichloromethane and methylchloride. These results indicate that reductive dehalogenation, which was mediated better by living sludge than by autoclaved sludge, is only a minor pathway for CT degradation. The main pathway involves substitutive and oxidative dechlorination reactions that lead to the formation of CO2. Granular sludge, therefore, has outstanding potential for gratuitous dechlorination of CT to safe end products. PMID:9647798

  18. Comparative Metabolism of Carbon Tetrachloride in Rats, Mice and Hamsters Using Gas Uptake and PBPK Modeling

    SciTech Connect

    Thrall, Karla D. ); Vucelick, Mark E.; Gies, Richard A. ); Zangar, Richard C. ); Weitz, Karl K. ); Poet, Torka S. ); Springer, David L. ); Grant, Donna M. ); Benson, Janet M.

    2000-08-25

    No study has comprehensively compared the rate of metabolism of carbon tetrachloride (CCl4) across species. Therefore, the in vivo metabolism of CCl4 was evaluated using groups of male animals (F344 rats, B6C3F1 mice, and Syrian hamsters) exposed to 40-1800 ppm CCl4 in a closed, recirculating gas-uptake system. For each species, an optimal fit of the family of uptake curves was obtained by adjusting Michaelis-Menten metabolic constants Km (affinity) and Vmax (capacity) using a physiologically based pharmacokinetic (PBPK) model. The results show that the mouse has a slightly higher capacity and lower affinity for metabolizing CCl4 compared to the rat, while the hamster has a higher capacity and lower affinity than either rat or mouse. A comparison of the Vmax to Km ratio, normalized for mg of liver protein (L/hr/mg) across species indicates that hamsters metabolize more CCl4 than either rats or mice, and should be more susceptible to CCl4-induced hepatotoxicity. These species comparisons were evaluated against toxicokinetic studies conducted in animals exposed by nose-only inhalation to 20 ppm 14C-labeled CCl4 for 4 hours. The toxicokinetic study results are consistent with the in vivo rates of metabolism, with rats eliminating less radioactivity associated with metabolism (14CO2 and urine/feces) and more radioactivity associated with the parent compound (radioactivity trapped on charcoal) compared to either hamsters or mice. The in vivo metabolic constants determined here, together with in vitro constants determined using rat, mouse, hamster and human liver microsomes, were used to estimate human in vivo metabolic rates of 1.49 mg/hr/kg body weight and 0.25 mg/L for Vmax and Km, respectively. Normalizing the rate of metabolism (Vmax/Km) by mg liver protein, the rate of metabolism of CCl4 differs across species, with hamster > mouse& > rat > human.

  19. Mechanisms of chloroform and carbon tetrachloride toxicity in primary cultured mouse hepatocytes

    SciTech Connect

    Ruch, R.J.; Klaunig, J.E.; Schultz, N.E.; Askari, A.B.; Lacher, D.A.; Pereira, M.A.; Goldblatt, P.J.

    1986-11-01

    Mechanisms of chloroform (CHCl/sub 3/) and carbon tetrachloride (CCl/sub 4/) toxicity to primary cultured male B6C3F1 mouse hepatocytes were investigated. The cytotoxicity of both CHCl/sub 3/ and CCl/sub 4/ was dose- and duration-dependent. Maximal hepatocyte toxicity, as determined by lactate dehydrogenase leakage into the culture medium, occurred with the highest concentrations of CHCl/sub 3/ (5 mM) and CCl/sub 4/ (2.5 mM) used and with the longest duration of treatment (20 hr). CCl/sub 4/ was approximately 16 times more toxic than CHCl/sub 3/ to the hepatocytes. The toxicity of these compounds was decreased by adding the mixed function oxidase system (MFOS) inhibitor, SKF-525A (25..mu..M) to the cultures. The addition of diethyl maleate (0.25 mM), which depletes intracellular glutathione (GSH)-potentiated CHCl/sub 3/ and CCl/sub 4/ toxicity. The toxicity of CHCl/sub 3/ and CCl/sub 4/ could also be decreased by adding the antioxidants N,N'-diphenyl-p-phenylenediamine (DPPD) (25..mu..M), ..cap alpha..-tocopherol acetate (Vitamin E) (0.1 mM), or superoxide dismutase (SOD) (100 U/mL) to the cultures. These results suggest that: in mouse hepatocytes, both CHCl/sub 3/ and CCl/sub 4/ are metabolized to toxic components by the MFOS; GSH plays a role in detoxifying those metabolites; free radicals are produced during the metabolism of CHCl/sub 3/ and CCl/sub 4/; and free radicals may be important mediators of the toxicity of these two halomethanes.

  20. Hepatoprotective Potential of Chestnut Bee Pollen on Carbon Tetrachloride-Induced Hepatic Damages in Rats

    PubMed Central

    Yıldız, Oktay; Can, Zehra; Saral, Özlem; Yuluğ, Esin; Öztürk, Ferhat; Aliyazıcıoğlu, Rezzan; Canpolat, Sinan; Kolaylı, Sevgi

    2013-01-01

    Bee pollen has been used as an apitherapy agent for several centuries to treat burns, wounds, gastrointestinal disorders, and various other diseases. The aim of our study was to investigate the hepatoprotective effects of chestnut bee pollen against carbon tetrachloride (CCI4)-induced liver damage. Total phenolic content, flavonoid, ferric reducing/antioxidant power, and DPPH radical activity measurements were used as antioxidant capacity determinants of the pollen. The study was conducted in rats as seven groups. Two different concentrations of chestnut bee pollens (200 and 400 mg/kg/day) were given orally and one group was administered with silibinin (50 mg/kg/day, i.p.) for seven days to the rats following the CCI4 treatment. The protective effect of the bee pollen was monitored by aspartate transaminase (AST) and alanine transaminase (AST) activities, histopathological imaging, and antioxidant parameters from the blood and liver samples of the rats. The results were compared with the silibinin-treated and untreated groups. We detected that CCI4 treatment induced liver damage and both the bee pollen and silibinin-treated groups reversed the damage; however, silibinin caused significant weight loss and mortality due, severe diarrhea in the rats. The chestnut pollen had showed 28.87 mg GAE/g DW of total phenolic substance, 8.07 mg QUE/g DW of total flavonoid, 92.71 mg Cyn-3-glu/kg DW of total anthocyanins, and 9 mg β-carotene/100 g DW of total carotenoid and substantial amount of antioxidant power according to FRAP and DPPH activity. The results demonstrated that the chestnut bee pollen protects the hepatocytes from the oxidative stress and promotes the healing of the liver damage induced by CCI4 toxicity. Our findings suggest that chestnut bee pollen can be used as a safe alternative to the silibinin in the treatment of liver injuries. PMID:24250716

  1. Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats

    PubMed Central

    Cordero-Pérez, Paula; Torres-González, Liliana; Aguirre-Garza, Marcelino; Camara-Lemarroy, Carlos; Guzmán-de la Garza, Francisco; Alarcón-Galván, Gabriela; Zapata-Chavira, Homero; de Jesús Sotelo-Gallegos, Ma.; Nadjedja Torres-Esquivel, Cipactli; Sánchez-Fresno, Ethel; Cantú-Sepúlveda, Daniel; González-Saldivar, Gerardo; Bernal-Ramirez, Judith; E. Muñoz-Espinosa, Linda

    2013-01-01

    Background: Various hepatoprotective herbal products from plants are available in Mexico, where up to 85% of patients with liver disease use some form of complementary and alternative medicine. However, only few studies have reported on the biological evaluation of these products. Objective: Using a model of carbon tetrachloride (CCl4)-induced hepatotoxicity in rats, we evaluated the effects of commercial herbal extracts used most commonly in the metropolitan area of Monterrey, Mexico. Materials and Methods: The commercial products were identified through surveys in public areas. The effect of these products given with or without CCl4 in rats was evaluated by measuring the serum concentrations of aspartate amino transferase (AST) and alanine amino transferase (ALT), and histopathological analysis. Legalon® was used as the standard drug. Results: The most commonly used herbal products were Hepatisan® capsules, Boldo capsules, Hepavida® capsules, Boldo infusion, and milk thistle herbal supplement (80% silymarin). None of the products tested was hepatotoxic according to transaminase and histological analyses. AST and ALT activities were significantly lower in the Hepavida+CCl4-treated group as compared with the CCl4-only group. AST and ALT activities in the silymarin, Hepatisan, and Boldo tea groups were similar to those in the CCl4 group. The CCl4 group displayed submassive confluent necrosis and mixed inflammatory infiltration. Both the Hepatisan+CCl4 and Boldo tea+CCl4 groups exhibited ballooning degeneration, inflammatory infiltration, and lytic necrosis. The silymarin+CCl4 group exhibited microvesicular steatosis. The Hepavida+CCl4- and Legalon+CCL4-treated groups had lower percentages of necrotic cells as compared with the CCl4-treated group; this treatment was hepatoprotective against necrosis. Conclusion: Only Hepavida had a hepatoprotective effect. PMID:23900881

  2. Metallocoenzyme-mediated reductive transformation of carbon tetrachloride in titanium (III) citrate aqueous solution

    SciTech Connect

    Chiu, P.C.; Reinhard, M.

    1995-03-01

    Transformation pathways for carbon tetrachloride (CCl{sub 4}) catalyzed by hematin or vitamin B{sub 12} in aqueous titanium(III) citrate solution are proposed. The reaction of CCl{sub 4} with B{sub 12} was zero order in CCl{sub 4} and first order in B{sub 12}, and the rate constant was measured from pH 7.3 to pH 10.3. The proposed rate-limiting step is the reduction of the stable trichloromethylcobalamin (CCl{sub 3}-Cbl) intermediate by titanium(III) citrate at alkaline pH and the sterically induced CCl{sub 3}-Cbl decomposition at neutral pH. The reaction kinetics can be described by a modified Michaelis-Menten model in the saturated regime. With hematin, only the pseudo-first-order rate constant was determined due to the significant deactivation of the coenzyme. The turnover number of hematin (molecules of CCl{sub 4} transformed/molecule of hematin deactivated) was 27 at pH 8.0 and 42 at pH 9.9. Vitamin B{sub 12} was a more stable and more effective catalyst (on a molar basis) than hematin with respect to CCl{sub 4}. Chloroform (CHCl{sub 3}) was the primary product in titanium(III) citrate solution, and the yield was a function of pH, Ti(III) concentration, and organic content regardless of whether a coenzyme was present or which coenzyme was used. Although B{sub 12} and hematin can both enhance the CCl{sub 4} transformation rate, they have little effect on the CHCl{sub 3} yield. Titanium(III) citrate, on the other hand, controls not only the transformation rate but also CHCl{sub 3} formation. 77 refs., 10 figs.

  3. Investigation of cell exudates active in carbon tetrachloride and chloroform degradation.

    PubMed

    Koons, B W; Baeseman, J L; Novak, P J

    2001-07-01

    Contamination of groundwater by chlorinated solvents such as carbon tetrachloride (CCl4) and chloroform (CHCl3) is a widespread problem. The cell exudates from the methanogen Methanosarcina thermophila are active in the degradation of CCl4 and CHCl3. This research was performed to characterize these exudates. Examination of the influence of pH indicated that activity was greater under alkaline conditions. Rapid CCl4 degradation occurred from 35-65 degrees C, with first-order degradation rate coefficients increasing as temperature increased. It was found that proteins were not responsible for CCl4 degradation. The active agents in the cell exudates were <10 kDa in size, with degradation activity present in both 1-10 kDa and <1 kDa size ranges. Upon purification of the <10 kDa size range of the cell exudates on a C(18) chromatography column, 17 fractions (out of 100) degraded >50% of the added CCl4 in 8 h. These 17 fractions were pooled into three samples based on their elution time from the C(18) column. One of these pooled samples contained elevated levels of cobalt, zinc, and iron, at 2, 3, and 13 times the levels measured in similarly fractionated and pooled samples of medium, respectively. The UV-visible spectrum of this pooled sample had an absorption maximum at 560-580 nm, which is similar to the absorption maxima of heme (approximately 550 and 575 nm). The two other pooled samples contained elevated levels of zinc at 11 and 22 times the concentration measured in similarly fractionated and pooled samples of medium, respectively, and also contained very low levels of nickel, cobalt, and iron. This research suggests that the cell exudates from M. thermophila contain porphorinogen-type molecules capable of dechlorination, possibly excreted corrinoids, hemes, and zinc-containing molecules.

  4. Hepatoprotective effects of allyl isothiocyanate against carbon tetrachloride-induced hepatotoxicity in rat.

    PubMed

    Ahn, Meejung; Kim, Jeongtae; Bang, Hyojin; Moon, Jihwan; Kim, Gi Ok; Shin, Taekyun

    2016-07-25

    We evaluated the hepatoprotective activity of allyl isothiocyanate (AITC) against carbon tetrachloride (CCl4)-induced liver injury in rats. Sprague Dawley rats were orally administered AITC at doses of 5 (AITC 5) and 50 (AITC 50) mg/kg body weight once daily for 3 days, with or without intraperitoneal injection of CCl4. Serum chemistry was assessed for changes in alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The enzyme activities of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were examined in liver tissues, while pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) mRNA expression were analyzed using real-time polymerase chain reaction. And heme oxygenase-1 (HO-1) and ionized calcium binding protein-1 (Iba-1) immunoreactivities were evaluated by Western blot analysis and immunohistochemistry, respectively. In serum chemistry, the oral administration of AITC itself did not affect the serum levels of ALT or AST, furthermore pretreatment with AITC 5 and AITC 50 significantly reduced the ALT and AST activity levels that were elevated in CCl4-intoxicated rats. In addition, AITC significantly suppressed the reduction of SOD and CAT, and the elevation of MDA, TNF-α mRNA expression, on the other hands, induced the expression of HO-1 compared with those of the vehicle-treated CCl4 group. The histopathological evaluation and Iba-1 immunoreactivity also supported the hepatoprotective effects of AITC against CCl4-induced liver injury. These results suggest that AITC ameliorates oxidative liver injury, possibly through reducing lipid peroxidation, enhancing antioxidant enzymes, and suppressing Kupffer cells and macrophages. PMID:27241356

  5. Caspase-12 mediates carbon tetrachloride-induced hepatocyte apoptosis in mice

    PubMed Central

    Liu, Hua; Wang, Zhe; Nowicki, Michael J

    2014-01-01

    AIM: To investigate the role of caspase-12 and its downstream targets in carbon tetrachloride (CCl4)-induced hepatocyte apoptosis. METHODS: The role of caspase-12 was determined by using caspase-12 knock-out (-/-) mice. CCl4 (300 μL/kg body weight) or vehicle (corn oil) was administered to caspase-12+/+ or caspase-12-/- mice as a single intraperitoneal injection. The animals were sacrificed 24 h after the CCl4 treatment. Blood was collected to evaluate liver function by the measurement of the activity of alanine aminotransferase. Liver samples were used for the measurements of reactive oxygen species using plasma malondialdehyde as biomarker, hepatocyte apoptosis was evaluated via terminal transferase-mediated dUTP nick-end labeling and controlled by morphologic study, and cytochrome C release and caspase activations were measured by Western blotting. RESULTS: Administration of a low dose of CCl4 resulted in hepatocyte apoptosis and acute liver injury in wild-type mice. CCl4 also induced the generation of reactive oxygen species and induction of endoplasmic reticulum stress in the liver followed by activations of caspase-12, -9 and -3 as well as release of small amounts of cytochrome C. However, in the CCl4-treated caspase-12-/- mice, activation of caspase-9 and -3 were significantly attenuated (P < 0.05); no effect was seen in cytochrome C release. CCl4-induced apoptosis and liver damage was markedly reduced in caspase-12-/- mice compared to caspase-12+/+ mice (P < 0.05). The active form of caspase-8 was not detected in either caspase-12+/+ or caspase-12-/- mice. There was no significant different in the formation of reactive oxygen species in the livers of caspase-12+/+ and caspase-12-/- mice treated with CCl4. CONCLUSION: Caspase-12 plays a pivotal role in CCl4-induced hepatic apoptosis through the activation of the downstream effector caspase-3 directly and/or indirectly via capase-9 activation. PMID:25561786

  6. Pigment Epithelium Derived Factor Peptide Protects Murine Hepatocytes from Carbon Tetrachloride-Induced Injury

    PubMed Central

    Shih, Shou-Chuan; Ho, Tsung-Chuan; Chen, Show-Li; Tsao, Yeou-Ping

    2016-01-01

    Fibrogenesis is induced by repeated injury to the liver and reactive regeneration and leads eventually to liver cirrhosis. Pigment epithelium derived factor (PEDF) has been shown to prevent liver fibrosis induced by carbon tetrachloride (CCl4). A 44 amino acid domain of PEDF (44-mer) was found to have a protective effect against various insults to several cell types. In this study, we investigated the capability of synthetic 44-mer to protect against liver injury in mice and in primary cultured hepatocytes. Acute liver injury, induced by CCl4, was evident from histological changes, such as cell necrosis, inflammation and apoptosis, and a concomitant reduction of glutathione (GSH) and GSH redox enzyme activities in the liver. Intraperitoneal injection of the 44-mer into CCl4-treated mice abolished the induction of AST and ALT and markedly reduced histological signs of liver injury. The 44-mer treatment can reduce hepatic oxidative stress as evident from lower levels of lipid hydroperoxide, and higher levels of GSH. CCl4 caused a reduction of Bcl-xL, PEDF and PPARγ, which was markedly restored by the 44-mer treatment. Consequently, the 44-mer suppressed liver fibrosis induced by repeated CCl4 injury. Furthermore, our observations in primary culture of rat hepatocytes showed that PEDF and the 44-mer protected primary rat hepatocytes against apoptosis induced by serum deprivation and TGF-β1. PEDF/44-mer induced cell protective STAT3 phosphorylation. Pharmacological STAT3 inhibition prevented the antiapoptotic action of PEDF/44-mer. Among several PEDF receptor candidates that may be responsible for hepatocyte protection, we demonstrated that PNPLA2 was essential for PEDF/44-mer-mediated STAT3 phosphorylation and antiapoptotic activity by using siRNA to selectively knockdown PNPLA2. In conclusion, the PEDF 44-mer protects hepatocytes from single and repeated CCl4 injury. This protective effect may stem from strengthening the counter oxidative stress capacity and

  7. Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing.

    PubMed

    Zhang, Gen; Mu, Yujing; Liu, Junfeng; Zhang, Chenglong; Zhang, Yuanyuan; Zhang, Yujie; Zhang, Hongxing

    2014-01-01

    Atmospheric peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and carbon tetrachloride (CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring (October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer (March to August), ranging from 1.37-3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values (below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September (1.14 ppbV). The monthly variation of CCl4 was tightly related to the variation of temperature, exhibiting a minimum in winter (69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3 showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon (ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn (R = 0.91), spring (R = 0.94), and summer (R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes (deltaO3/deltaPAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3 consumption by NO titration and less thermal decompositin of PAN.

  8. Hepatoprotective effects of licochalcone B on carbon tetrachloride-induced liver toxicity in mice

    PubMed Central

    Teng, Haifeng; Chen, Meng; Zou, Ansheng; Jiang, Haili; Han, Jichun; Sun, Long; Feng, Chao; Liu, Ju

    2016-01-01

    Objective(s): The objective of this study was to investigate the hepatoprotective effect of licochalcone B (LCB) in a mice model of carbon tetrachloride (CCl4)-induced liver toxicity. Materials and Methods: Hepatotoxicity was induced in mice by a single subcutaneous injection (SC) of CCl4. The LCB was administered orally once a day for seven days (PO) as pretreatment at three doses of 1, 5, and 25 mg/kg/day. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed by ELISA. The protein expression degrees of p38 mitogen activated protein kinases (p38) and nuclear factor-k-gene binding (NF-κB) were assayed by western blotting. Results: CCl4-induced hepatotoxicity was manifested by an increase in the levels of ALT, AST, MDA, IL-6, CRP, and TNF-ɑ, and a decrease in the SOD level and GSH/GSSG ratio in the serum. The histopathological examination of the liver sections revealed necrosis and inflammatory reactions. Pretreatment with LCB decreased the levels of ALT, AST, MDA, GSSG, IL-6, CRP, TNF-ɑ, and the protein expression of p38 and NF-κB, increased the level of SOD and GSH, and normalized the hepatic histo-architecture. Conclusion: LCB protected the liver from CCl4-induced injury. Protection may be due to inhibition of p38 and NFκB signaling, which subsequently reduced inflammation in the liver. PMID:27746874

  9. Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing.

    PubMed

    Zhang, Gen; Mu, Yujing; Liu, Junfeng; Zhang, Chenglong; Zhang, Yuanyuan; Zhang, Yujie; Zhang, Hongxing

    2014-01-01

    Atmospheric peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and carbon tetrachloride (CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring (October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer (March to August), ranging from 1.37-3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values (below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September (1.14 ppbV). The monthly variation of CCl4 was tightly related to the variation of temperature, exhibiting a minimum in winter (69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3 showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon (ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn (R = 0.91), spring (R = 0.94), and summer (R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes (deltaO3/deltaPAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3 consumption by NO titration and less thermal decompositin of PAN. PMID:24649692

  10. Carbon Tetrachloride Flow and Transport in the Subsurface of the 216-Z-18 Crib and 216-Z-1A Tile Field at the Hanford Site: Multifluid Flow Simulations and Conceptual Model Update

    SciTech Connect

    Oostrom, Mart; Rockhold, Mark L.; Thorne, Paul D.; Last, George V.; Truex, Michael J.

    2006-10-31

    Carbon tetrachloride (CT) was discharged to the 216-Z-9, Z-1A, and Z-18 waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the conceptual model of how CT is distributed in the Hanford 200 West Area subsurface through use of numerical flow and transport modeling. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy.

  11. [Effect of Silybum marianum oil and legalon on lipid peroxidation and liver antioxidant systems in rats intoxicated with carbon tetrachloride].

    PubMed

    Batakov, E A

    2001-01-01

    An oil obtained from the seeds of Saint-Mary thistle (Silybum marianum) and the drug legalon (silybinin) prepared from this plant produce an antioxidant effect on liver tissues of rats poisoned with carbon tetrachloride. Legalon (25 mg/kg) and the oil (2000 mg) reduced the level of lipid peroxidation, increased the catalase activity, but did not reduce the concentration of selenium in liver (which decreased as a result of CCl4 intoxication). Legalon significantly increased the activity of superoxide dismutase in liver tissues, while the Saint-Mary thistle oil did not produce such effect.

  12. Simultaneous anaerobic transformation of tetrachloroethene and carbon tetrachloride in a continuous flow column

    NASA Astrophysics Data System (ADS)

    Azizian, Mohammad F.; Semprini, Lewis

    2016-07-01

    Tetrachloroethene (PCE) and carbon tetrachloride (CT) were simultaneously transformed in a packed column that was bioaugmented with the Evanite culture (EV). The data presented here have been obtained over a period of 1930 days. Initially the column was continuously fed synthetic groundwater with PCE (0.1 mM), sulfate (SO42 -) (0.2 mM) and formate (2.1 mM) or lactate (1.1 mM), but not CT. In these early stages of the study the effluent H2 concentrations ranged from 7 to 19 nM, and PCE was transformed to ethene (ETH) (81 to 85%) and vinyl chloride (VC) (11 to 17%), and SO42 - was completely reduced when using either lactate or formate as electron donors. SO42 - reduction occurred concurrently with cis-DCE and VC dehalogenation. Formate was a more effective substrate for promoting dehalogenation based on electron donor utilization efficiency. Simultaneous PCE and CT tests found CT (0.015 mM) was completely transformed with 20% observed as chloroform (CF) and trace amounts of chloromethane (CM) and dichloromethane (DCM), but no methane (CH4) or carbon disulfide (CS2). PCE transformation to ETH improved with CT addition in response to increases in H2 concentrations to 160 nM that resulted from acetate formation being inhibited by either CT or CF. Lactate fermentation was negatively impacted after CT transformation tests, with propionate accumulating, and H2 concentrations being reduced to below 1 nM. Under these conditions both SO42 - reduction and dehalogenation were negatively impacted, with sulfate reduction not occurring and PCE being transformed to cis-dichloroethene (c-DCE) (52%) and VC (41%). Upon switching to formate, H2 concentrations increased to 40 nM, and complete SO42 - reduction was achieved, while PCE was transformed to ETH (98%) and VC (1%), with no acetate detected. Throughout the study PCE dehalogenation to ethene was positively correlated with the effluent H2 concentrations.

  13. Localization and Characterization of the Carbon Tetrachloride Transformation Activity of Pseudomonas sp. Strain KC

    PubMed Central

    Dybas, M. J.; Tatara, G. M.; Criddle, C. S.

    1995-01-01

    Previous research has established that Pseudomonas sp. strain KC rapidly transforms carbon tetrachloride (CT) to carbon dioxide (45 to 55%), a nonvolatile fraction (45 to 55%), and a cell-associated fraction ((equiv)5%) under denitrifying, iron-limited conditions. The present study provides additional characterization of the nonvolatile fraction, demonstrates that electron transfer plays a role in the transformation, and establishes the importance of both extracellular and intracellular factors. Experiments with (sup14)C-labeled CT indicate that more than one nonvolatile product is produced during CT transformation by strain KC. One of these products, accounting for about 20% of the [(sup14)C]CT transformed, was identified as formate on the basis of its elution time from an ion-exchange column, its boiling point, and its conversion to (sup14)CO(inf2) when incubated with formate dehydrogenase. Production of formate requires transfer of two electrons to the CT molecule. The role of electron transfer was also supported by experiments demonstrating that stationary-phase cells that do not transform CT can be stimulated to transform CT when supplemented with acetate (electron donor), nitrate (electron acceptor), or a protonophore (carbonyl cyanide m-chlorophenylhydrazone). The location of transformation activity was also evaluated. By themselves, washed cells did not transform CT to a significant degree. Occasionally, CT transformation was observed by cell-free culture supernatant, but this activity was not reliable. Rapid and reliable CT transformation was only obtained when washed whole cells were reconstituted with culture supernatant, indicating that both extracellular and intracellular factors are normally required for CT transformation. Fractionation of culture supernatant by ultrafiltration established that the extracellular factor or factors are small, with an apparent molecular mass of less than 500 Da. The extracellular factor or factors were stable after

  14. Carbon Doping of Compound Semiconductor Epitaxial Layers Grown by Metalorganic Chemical Vapor Deposition Using Carbon Tetrachloride.

    NASA Astrophysics Data System (ADS)

    Cunningham, Brian Thomas

    1990-01-01

    A dilute mixture of CCl_4 in high purity H_2 has been used as a carbon dopant source for rm Al_ {x}Ga_{1-x}As grown by low pressure metalorganic chemical vapor deposition (MOCVD). To understand the mechanism for carbon incorporation from CCl_4 doping and to provide experimental parameters for the growth of carbon doped device structures, the effects of various crystal growth parameters on CCl _4 doping have been studied, including growth temperature, growth rate, V/III ratio, Al composition, and CCl_4 flow rate. Although CCl _4 is an effective p-type dopant for MOCVD rm Al_{x}Ga_ {1-x}As, injection of CCl_4 into the reactor during growth of InP resulted in no change in the carrier concentration or carbon concentration. Abrupt, heavy carbon doping spikes in GaAs have been obtained using CCl_4 without a dopant memory effect. By annealing samples with carbon doping spikes grown within undoped, n-type, and p-type GaAs, the carbon diffusion coefficient in GaAs at 825 ^circC has been estimated and has been found to depend strongly on the GaAs background doping. Heavily carbon doped rm Al_{x}Ga _{1-x}As/GaAs superlattices have been found to be more stable against impurity induced layer disordering (IILD) than Mg or Zn doped superlattices, indicating that the low carbon diffusion coefficient limits the IILD process. Carbon doping has been used in the base region on an Npn AlGaAs/GaAs heterojunction bipolar transistor (HBT). Transistors with 3 x 10 μm self-aligned emitter fingers have been fabricated which exhibit a current gain cutoff frequency of f_ {rm t} = 26 GHz.

  15. Phenylbutyric acid protects against carbon tetrachloride-induced hepatic fibrogenesis in mice

    SciTech Connect

    Wang, Jian-Qing; Chen, Xi; Zhang, Cheng; Tao, Li; Zhang, Zhi-Hui; Liu, Xiao-Qian; Xu, Yuan-Bao; Wang, Hua; Li, Jun; Xu, De-Xiang

    2013-01-15

    A recent report showed that the unfolded protein response (UPR) signaling was activated in the pathogenesis of carbon tetrachloride (CCl{sub 4})-induced hepatic fibrosis. Phenylbutyric acid (PBA) is a well-known chemical chaperone that inhibits endoplasmic reticulum (ER) stress and unfolded protein response (UPR) signaling. In the present study, we investigated the effects of PBA on CCl{sub 4}-induced hepatic fibrosis in mice. All mice were intraperitoneally (i.p.) injected with CCl{sub 4} (0.15 ml/kg BW, twice per week) for 8 weeks. In CCl{sub 4} + PBA group, mice were i.p. injected with PBA (150 mg/kg, twice per day) from the beginning of CCl{sub 4} injection to the end. As expected, PBA significantly attenuated CCl{sub 4}-induced hepatic ER stress and UPR activation. Although PBA alleviated, only to a less extent, hepatic necrosis, it obviously inhibited CCl{sub 4}-induced tumor necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β). Moreover, PBA inhibited CCl{sub 4}-induced hepatic nuclear factor kappa B (NF-κB) p65 translocation and extracellular signal-regulated kinase (ERK) and c-Jun N-terminal Kinase (JNK) phosphorylation. Interestingly, CCl{sub 4}-induced α-smooth muscle actin (α-SMA), a marker for the initiation phase of HSC activation, was significantly attenuated in mice pretreated with PBA. Correspondingly, CCl{sub 4}-induced hepatic collagen (Col)1α1 and Col1α2, markers for the perpetuation phase of HSC activation, were inhibited in PBA-treated mice. Importantly, CCl{sub 4}-induced hepatic fibrosis, as determined using Sirius red staining, was obviously attenuated by PBA. In conclusion, PBA prevents CCl{sub 4}-induced hepatic fibrosis through inhibiting hepatic inflammatory response and HSC activation. Highlights: ► CCl{sub 4} induces hepatic ER stress, inflammation, HSC activation and hepatic fibrosis. ► PBA alleviates CCl{sub 4}-induced hepatic ER stress and UPR signaling activation. ► PBA inhibits CCl{sub 4}-induced

  16. Solving the carbon tetrachloride (CCl4) budget mystery using surface observations

    NASA Astrophysics Data System (ADS)

    Liang, Q.; Newman, P. A.; Daniel, J. S.; Reimann, S.; Hall, B. D.; Dutton, G. S.; Kuijpers, L. J. M.

    2014-12-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance, with an ozone depletion potential (with respect to CFC-11) of 0.82. CCl4 is also a greenhouse gas and the 100-yr global warming potential is 1,400. In 1987, the Montreal Protocol (MP) included CCl4, and production and consumption were phased out for developed countries in 1996. Developing countries were allowed a delayed reduction, but CCl4 was fully phased out from emissive uses in 2010. However, the near-zero 2007-2012 emissions estimate based on the UNEP reported production and feedstock usage cannot be reconciled with the observed slow decline of atmospheric concentrations, year-to-year variability, and the inter-hemispheric gradient (IHG). We use available source and sink data in the NASA 3-Dimensional (3-D) Chemistry Climate Model, GEOSCCM, to test existing emissions and lifetime estimates against CCl4 mixing ratio observations. Our model results show that the IHG and global trend provide useful information for quantitatively constraining CCl4 emissions and lifetime estimates. The observed IHG (1.5±0.2 ppt for 2000-2012) is primarily caused by ongoing current emissions, while ocean and soil losses and stratosphere-troposphere exchange together contribute a small negative gradient (~0 - -0.3 ppt). Using the observed CCl4 global trend and IHG from the National Oceanic and Atmospheric Administration - Global Monitoring Division (NOAA-GMD) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks, we deduce the mean global emissions for the 2000-2012 period are 39 (34-45, lower-upper limit emission estimates) Gg/yr (~ 30% of the peak 1980s emissions) and a corresponding total lifetime of 35 (37-32, upper-lower limit lifetime estimates) years. These results point to the need for a more accurate bottom-up estimate of CCl4 emissions as well as re-evaluation of the CCl4 best estimate lifetime (currently 25 years).

  17. Carbon Tetrachloride (CCl4) in the Atmosphere: A Mystery Between Sources and Sinks

    NASA Astrophysics Data System (ADS)

    Reimann, S.; Newman, P. A.; Liang, Q.; Rigby, M. L.; Kuijpers, L.

    2013-12-01

    Carbon tetrachloride (CCl4) is an ozone depleting substance and therefore has been banned from usage under the Montreal Protocol. However, it is still allowed for contained use in industrial processes as so-called feedstock substance, where emissions should be negligible. The regulation of CCl4 in the Montreal Protocol suggests that, presently, emission should be zero, and that CCl4 ought to be declining exponentially depending on its atmospheric lifetime. Although atmospheric CCl4 concentrations are declining, the rate is slower than expected, suggesting that there is an unknown source of CCl4 or that the combined partial lifetimes in different environmental compartments (atmosphere, ocean, soil) are slower than our understood processes. In the last years there were increasing discrepancies between emissions reported under the Montreal Protocol ('bottom-up method') and those which are inferred from measurements at global background sites ('top-down method'). In 2012 the potential gap in global emissions between the two methods widened to several ten thousand tons per year. In order to close this gap several possibilities were tested with atmospheric models and results are verified against the global trends and the interhemispheric gradients. 1) Existing data from sources and sinks were fed into the models to test the incompatibility of the existing emission data with the observed atmospheric observation for CCl4. 2) A newly revised 44-year steady-state atmospheric lifetime was assessed. This new lifetime together with an improved uncertainty has been carefully evaluated within a lifetime assessment for ODSs and related substances under SPARC (Stratosphere-troposphere Processes And their Role in Climate). The new atmospheric lifetime is substantially longer than the 35-years which were used in WMO (2011) for the atmosphere alone. However, estimates of soil sinks (195 yr) and ocean sinks (81 yr) lead to a best-estimated global lifetime of only 25 years, comparable

  18. Improved risk estimated from carbon tetrachloride. Annual progress report, October 1, 1996--September 30, 1997

    SciTech Connect

    Benson, J.M.

    1997-10-27

    'Carbon tetrachloride (CCl{sub 4}) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. Rocky Flats was formerly the largest volume user of CCl{sub 4} in the US, with 5,000 gallons used there in 1977 alone. At the Hanford site, several hundred thousand gallons of CCl{sub 4} were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl{sub 4} in groundwater at highly contaminated sites at the Hanford. facility have exceeded the drinking water standard of 5 ppb by several orders of magnitude. High levels of CCl{sub 4} at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl{sub 4} cleanup required at these sites and associated costs are driven by current human health risk estimates which assume that CCl{sub 4} is a genotoxic carcinogen. The overall purpose of these studies is to improve the scientific basis for assessing the health risk associated with human exposure to CCl{sub 4}. Specifically, the authors will determine the toxicokinetics of inhaled and ingested CCl{sub 4} in F344/Crl rats, B6C3F1 mice, and Syrian hamsters. They will also evaluate species differences in the metabolism of CCl{sub 4} by rats, mice, hamsters, and man. Dose-response relationships will be determined in all these studies. This information will be used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). They will also provide scientific evidence that CCl{sub 4} , like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation. In combination, the studies outlined in this proposal will provide the exact types of information needed to enable refined cancer risk estimates for CCl{sub 4} under the new guidelines for risk assessment proposed by the

  19. Aqueous extract of Terminalia arjuna prevents carbon tetrachloride induced hepatic and renal disorders

    PubMed Central

    Manna, Prasenjit; Sinha, Mahua; Sil, Parames C

    2006-01-01

    Background Carbon tetrachloride (CCl4) is a well-known hepatotoxin and exposure to this chemical is known to induce oxidative stress and causes liver injury by the formation of free radicals. Acute and chronic renal damage are also very common pathophysiologic disturbances caused by CCl4. The present study has been conducted to evaluate the protective role of the aqueous extract of the bark of Termnalia arjuna (TA), an important Indian medicinal plant widely used in the preparation of ayurvedic formulations, on CCl4 induced oxidative stress and resultant dysfunction in the livers and kidneys of mice. Methods Animals were pretreated with the aqueous extract of TA (50 mg/kg body weight) for one week and then challenged with CCl4 (1 ml/kg body weight) in liquid paraffin (1:1, v/v) for 2 days. Serum marker enzymes, namely, glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP) were estimated in the sera of all study groups. Antioxidant status in both the liver and kidney tissues were estimated by determining the activities of the antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST); as well as by determining the levels of thiobarbutaric acid reactive substances (TBARS) and reduced glutathione (GSH). In addition, free radical scavenging activity of the extract was determined from its DPPH radical quenching ability. Results Results showed that CCl4 caused a marked rise in serum levels of GPT and ALP. TBARS level was also increased significantly whereas GSH, SOD, CAT and GST levels were decreased in the liver and kidney tissue homogenates of CCl4 treated mice. Aqueous extract of TA successfully prevented the alterations of these effects in the experimental animals. Data also showed that the extract possessed strong free radical scavenging activity comparable to that of vitamin C. Conclusion Our study demonstrated that the aqueous extract of the bark of TA could protect the liver and kidney tissues against CCl4

  20. Phycocyanobilin accelerates liver regeneration and reduces mortality rate in carbon tetrachloride-induced liver injury mice

    PubMed Central

    Liu, Jie; Zhang, Qing-Yu; Yu, Li-Ming; Liu, Bin; Li, Ming-Yi; Zhu, Run-Zhi

    2015-01-01

    AIM: To investigate the hepatoprotective effects of phycocyanobilin (PCB) in reducing hepatic injury and accelerating hepatocyte proliferation following carbon tetrachloride (CCl4) treatment. METHODS: C57BL/6 mice were orally administered PCB 100 mg/kg for 4 d after CCl4 injection, and then the serum and liver tissue of the mice were collected at days 1, 2, 3, 5 and 7 after CCl4 treatment. A series of evaluations were performed to identify the curative effects on liver injury and recovery. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin and superoxide dismutase (SOD) were detected to indirectly assess the anti-inflammatory effects of PCB. Meanwhile, we detected the expressions of hepatocyte growth factor, transforming growth factor alpha (TGF-α), TGF-β, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), the factors which are associated with inflammation and liver regeneration. The protein expressions of proliferating cell nuclear antigen (PCNA), TNF-α and cytochrome C were detected by western blot. Furthermore, the survival rates were analyzed of mice which were administered a lethal dose of CCl4 (2.6 mg/kg) with or without PCB. RESULTS: In our research, PCB showed a strongly anti-inflammatory effect on CCl4-induced liver injury in mice. The ALT was significantly decreased after CCl4 treatment from day 1 (P < 0.01) and the AST was significantly decreased from day 2 (P < 0.001). Both albumin and liver SOD were increased from day 2 (P < 0.001 and P < 0.01), but serum SOD levels did not show a significant increase (P > 0.05). PCB protected the structure of liver from the injury by CCl4. TUNEL assay showed that PCB dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control (101.0 ± 25.4 vs 25.7 ± 6.4, P < 0.01). The result of western blotting showed that PCB could increase PCNA expression, decrease TNF-α and cytochrome C expression. Furthermore, data shows that PCB could improve the

  1. Ethanol and food deprivation induced enhancement of hepatotoxicity in rats given carbon tetrachloride at low concentration.

    PubMed Central

    Ikatsu, H; Okino, T; Nakajima, T

    1991-01-01

    Effects of chronic ethanol consumption and one day food deprivation on the hepatotoxicity of low dose carbon tetrachloride (CCl4; 0 to 100 ppm inhalation for eight hours) in rats were investigated by using biochemical and histopathological methods. Liver malondialdehyde (MDA) contents were significantly increased by exposure to 5 ppm to 50 ppm CCl4 in ethanol treated rats or by exposure to 25 ppm to 50 ppm CCl4 in food deprived rats but not in rats without ethanol or food deprivation. The MDA concentrations reached a maximum at 10 ppm and 50 ppm CCl4 in ethanol treated and food deprived rats, respectively, and decreased to the non-exposed concentration at 100 ppm CCl4. At greater than or equal to 50 ppm CCl4 plasma MDA contents increased significantly only in ethanol treated rats. None of the exposure concentrations influenced plasma glutamic-oxaloacetic transamidase (GOT) and glutamic-pyruvic transaminase (GPT) activities in rats that were only exposed to CCl4 whereas exposure to 10 ppm or higher concentrations combined with ethanol increased both activities. To a lesser extent food deprivation combined with exposure to greater than or equal to 25 ppm CCl4 had the same effect. No histopathological changes were found in the liver of rats exposed to less than or equal to 10 ppm CCl4, and only a few ballooned hepatocytes were seen in centrilobular areas when exposure was 25 ppm or higher. The presence of ballooned and hepatocytes became a regular feature of mid-zonal areas in ethanol treated rats and in the centrilobular areas of food deprived rats after exposure to /=25 ppm and >/=50 ppm respectively. These results indicate that consumption of ethanol and food deprivation potentiate CCl(4) induced hepatic damage even at low concentrations of CCl(4) by promoting lipid peroxidation. Thus heavy

  2. The role of Urtica dioica and Nigella sativa in the prevention of carbon tetrachloride-induced hepatotoxicity in rats.

    PubMed

    Türkdoğan, M K; Ozbek, H; Yener, Z; Tuncer, I; Uygan, I; Ceylan, E

    2003-09-01

    The role of Nigella sativa L. (Ranunculaceae) (NS) and Urtica dioica L. was investigated (UD) in the prevention of carbon tetrachloride (CCl4) induced liver fibrosis and cirrhosis. Fifty Sprague-Dawley rats were allocated into fi ve groups (I, IIA and B, IIIA and B) and CCl4 was injected biweekly to all groups. Group I (control, CCl4 only), group IIA and B (NS fixed oil and volatile oil), group IIIA and B (UD fixed oil and UD decoction extract) rats were killed at the end of week 12 and histopathological and immunohistochemical examinations of liver tissues were performed. In the control group, coagulation necrosis and hydropic degeneration were marked in the periacinar regions (zone 3) associated with fibrosis in the periacinar regions and in the portal tracts. In groups IIA-B and IIIA-B (NS and UD), none of the serious histopathological findings were detected except for sparse coagulation necrosis in the periacinar regions. ASMA-positive perisinusoidal cells with myo fibroblastic transformation and lysosomal enzyme activity suggesting fibrogenesis were also significantly more common in the control group than in the NS and UD groups. UD and NS seem to be significantly effective in the prevention of carbon tetrachloride induced hepatotoxicity in rats. PMID:13680830

  3. Protective effect of hesperidin on oxidative and histological liver damage following carbon tetrachloride administration in Wistar rats

    PubMed Central

    Çiftçi, Osman; Otlu, Ali

    2016-01-01

    Introduction In the current study, the protective effect of hesperidin (HP) on carbon tetrachloride (CCl4)-induced hepatotoxicity in rats was investigated. Material and methods Twenty-eight rats were divided equally into four groups. The first group was kept as a control and given only vehicle. In the second, rats were orally administered 50 mg/kg/day HP for 10 days. Carbon tetrachloride was given in a single intraperitoneal injection at the dose of 2 ml/kg in the third group. In the fourth group, the rats were treated with equal doses of CCl4 and HP. Results It was found that CCl4 induced oxidative stress via a significant increase in the formation of thiobarbituric acid-reactive substances (TBARS) and caused a significant decline in the levels of glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) in rats. In contrast, HP blocked these toxic effects induced by CCl4, causing an increase in GSH, CAT and SOD levels and decreased formation of TBARS (p < 0.01). In addition, histopathological damage increased with CCl4 treatment. In contrast, HP treatment eliminated the effects of CCl4 and stimulated anti-apoptotic events, as characterized by reduced caspase-3 activation. Conclusions The current study demonstrated that CCl4-induced hepatotoxicity can be prevented with HP treatment. Thus, co-administration of HP with CCl4 may be useful for attenuating the negative effects of CCl4 on the liver. PMID:27279838

  4. Revised Geostatistical Analysis of the Inventory of Carbon Tetrachloride in the Unconfined Aquifer in the 200 West Area of the Hanford Site

    SciTech Connect

    Murray, Christopher J.; Bott, Yi-Ju

    2008-12-30

    This report provides an updated estimate of the inventory of carbon tetrachloride (CTET) in the unconfined aquifer in the 200 West Area of the Hanford Site. The contaminant plumes of interest extend within the 200-ZP-1 and 200-UP-1 operable units. CH2M HILL Plateau Remediation Company (CHPRC) currently is preparing a plan identifying locations for groundwater extraction wells, injection wells, transfer stations, and one or more treatment facilities to address contaminants of concern identified in the 200-ZP-1 CERCLA Record of Decision. To accomplish this, a current understanding of the inventory of CTET is needed throughout the unconfined aquifer in the 200 West Area. Pacific Northwest National Laboratory (PNNL) previously developed an estimate of the CTET inventory in the area using a Monte Carlo approach based on geostatistical simulation of the three-dimensional (3D) distribution of CTET and chloroform in the aquifer. Fluor Hanford, Inc. (FH) (the previous site contractor) requested PNNL to update that inventory estimate using as input a set of geostatistical realizations of CTET and chloroform recently created for a related but separate project, referred to as the mapping project. The scope of work for the inventory revision complemented the scope of work for the mapping project, performed for FH by PNNL. This report briefly describes the spatial and univariate distribution of the CTET and chloroform data, along with the results of the geostatistical analysis and simulation performed for the mapping project.

  5. Vapour breakthrough behaviour of carbon tetrachloride - A simulant for chemical warfare agent on ASZMT carbon: A comparative study with whetlerite carbon

    NASA Astrophysics Data System (ADS)

    Srivastava, Avanish Kumar; Shah, Dilip K.; Mahato, T. H.; Roy, A.; Yadav, S. S.; Srivas, S. K.; Singh, Beer

    2013-06-01

    ASZMT and whetlerite carbon was prepared by impregnation of active carbon with ammonical salts of Cu (II), Ag (I), Zn (II), Mo (VI), TEDA and Cu (II), Ag (I), Cr (VI), NaOH, C5H5N respectively using incipient wetness technique. Thereafter, impregnated carbon systems were characterized using scanning electron microscopy, energy dispersive X-ray, atomic absorption spectroscopy, thermogravimetry and surface characterization techniques. Impregnated carbon systems were evaluated under dynamic conditions against carbon tetrachloride (CCl4) vapour that was used as a simulant for the persistent chemical warfare agents for testing breakthrough times of filter cartridges and canisters of gas masks in the national approval test of respirators. The protective potential of ASZMT carbon was compared with the whetlerite carbon which is presently used in NBC filtration system. The effect of CCl4 concentration, test flow rate, temperature and relative humidity on the breakthrough behaviour of the impregnated carbon systems has also been studied. The study clearly indicated that the whetlerite carbon possessed breakthrough time greater than ASZMT carbon. However, ASZMT carbon provided adequate protection against CCl4 vapours and can be used as an alternative to whetlerite carbon that contain Cr(VI), which is reported to be carcinogenic and having lesser shelf life. The study indicated the breakthrough time of impregnated carbon systems were found to decrease with the increase of the CCl4 concentration and flow rate. The variation in temperature and relative humidity did not significantly affect the breakthrough behaviour of impregnated carbon systems at high vapour concentration of CCl4 whereasbreak through time of impregnated carbon systems reduced by an increase of relative humidity at low CCl4 vapour concentration.

  6. Abiotic Degradation Rates for Carbon Tetrachloride: and Chloroform: Progress in FY 2008

    SciTech Connect

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Wietsma, Thomas W.; Truex, Michael J.

    2008-10-31

    This is a letter report summarizing work performed in FY2008 to determine the rates of carbon tetrachloride hydrolysis at temperatures close to actual groundwater temperatures. The report describes the project, the methodology, and the results obtained since the project's inception in FY2006. Measurements of hydrolysis rates in homogeneous solution have been completed for temperaturs of 70 C through 40 C, with additional data available at 30 C and 20 C. These results show no difference between the rates in deionized H2O and in filter-sterilized Hanford-Site groundwater. Moreover, the rates measured are 2-3 times slower than predicted from the open literature. Measurements of rates involving sterile suspensions of Hanford-Site sediment in Hanford-Site groundwater, however, show faster hydrolysis at temperatures below 40 C. Extrapolation of the current data available suggests a six-fold increase in rate would be expected at groundwater temperature of 16 C due to the presence of the sediment. This result translates into a 78-year half-life, rather than the 470-680 year half-life that would be predicted from rate determinations in homogeneous solution. The hydrolysis rate data at 20 C, in contrast to those at higher temperatures, are preliminary and have low statistical power. While significant (p < 0.05) differences between the heterogeneous and homogeneous systems are seen at 30 C, the results at 20 C are not statistically significant at this level due to limited data and the very slow nature of the reaction. More time is needed to collect data at these low temperatures to improve the statistical power of our observation. Given the critical need for hydrolysis rate data at temperatures relevant to groundwater systems, we have three recommendations for future work. First, we recommend a continuation of the sampling and analysis of the remaining long-term sealed-ampule experiments described in this report. These are primarily 20 C and 30 C experiments. The data at 20

  7. Interferon-alpha gene therapy prevents aflatoxin and carbon tetrachloride promoted hepatic carcinogenesis in rats.

    PubMed

    Aziz, Talaat Abdel; Aziz, Mohammed Abdel; Fouad, Hanan Hassan; Rashed, Laila Ahmed; Salama, Hosny; Abd-Alla, Samira; Wehab, Mosaad Attia Abdel; Ahmed, Tauseef

    2005-01-01

    Retrovirus-mediated interferon alpha (IFN-alpha) gene transfer was evaluated with regard to its possible protective effects against aflatoxin B1 (AFB1)-initiated and carbon tetrachloride (CCl4)-promoted hepatic carcinogenesis in rats. To our knowledge, this is the first time an experimental in vivo gene therapy trial was conducted in Egypt. Two genes were examined in liver tissue by RT-PCR: the first was glutathione-S-transferase placental (GST-P) isoenzyme, as an early marker to detect hepatic malignancy; the second was IFN-alpha gene expression to detect the efficiency of gene uptake and its persistence after transduction. Forty male rats, divided equally into 4 groups, were included in the study: the first group was the control; the second group received CCl4 0.2 ml subcutaneously twice weekly for 12 weeks and AFB1 0.25 mg/kg body wt intraperitoneally twice weekly for 6 weeks; the third group received IFN-alpha (10(8) pfu) intravenously in the tail vein prior to the start of CCl4 and AFB1 injections; and the fourth group received IFN-alpha (10(8) pfu) by intrahepatic injection under ultrasonography guide after termination of the CCl4 and AFB1 injection schedule. The results showed that IFN-alpha has a marked and significant protective effect against hepatic fibrogenesis as well as hepatic carcinogenesis. Pathological examination of liver tissue proved that IFN-alpha minimized both fibrotic and cirrhotic processes. The amount of fibrosis was less in both groups receiving IFN-alpha, with more protection in the group that received IFN-alpha intravenously prior to CCl4 and AFB1. The results of RT-PCR showed that the IFN-alpha gene was significantly expressed in both groups receiving IFN-alpha, with a more intense expression in the group that received IFN-alpha by intrahepatic injection after termination of CCl4 and AFB1 injections. The IFN-alpha gene was detected after three months of gene transduction in rats receiving IFN-alpha intravenously prior to CCl4 and AFB1

  8. Treatment with bovine gallstones exacerbates liver damage, but enhances hepatoprotection by bear gall powder in carbon tetrachloride-intoxicated rats.

    PubMed

    Nakashima, T; Matsumoto, N; Kashima, K

    1998-03-01

    The interactions between bovine gallstones (Goou) and bear gall powder (Yutan) in decreases in serum transaminase levels were investigated in rats intoxicated with carbon tetrachloride (CCl4). The p.o. administration of Goou significantly increased both serum transaminase levels and hepatic lipid peroxidation following i.p. administration of CCl4. Concomitant administration of both Goou and Yutan resulted in decreases of serum transaminase levels and hepatic lipid peroxidation, which were more remarkable than with administration of Yutan alone. Goou significantly increased the estimated hepatic blood flow in the indocyanine green clearance test and enhanced the delivery of CCl4 to the liver from the peritoneal cavity. These findings suggest that Goou exacerbates CCl4-induced hepatic damage because of the accelerated delivery of CCl4 to the liver and that Goou might have a hemodynamic drug interaction with Yutan in the liver, possibly enhancing the hepatoprotective effect of Yutan.

  9. Synergistic Extraction of Copper from Nitrate Solutions Using β-Hydroxy-Naphthaldoxime and Organophosphorus Compounds into Carbon-Tetrachloride

    NASA Astrophysics Data System (ADS)

    Dey, Pulak; Basu, Sukalyan

    2011-12-01

    The extraction behavior of Cu(II) from an aqueous nitrate medium employing β-hydroxy-naphthaldoxime in carbon tetrachloride has been investigated in the presence of several organophosphorus donors like tri-octyl phosphine oxide, tri-butyl phosphine oxide, and tri-butyl phosphate at pH 1.5. The concentration of the metal was measured by atomic absorption spectrophotometry. Synergism was observed when neutral donor was added because of the formation of the adduct [Cu(L)2.(S)] in CCl4 (S denotes neutral donor). The equilibrium constants of the binary system using β-hydroxy-naphthaldoxime and the ternary system involving another addition of an organophosphorus compound were calculated from the extraction date obtained. Furthermore, the temperature dependence of the equilibrium constants was also investigated to evaluate standard enthalpy (Δ H°), entropy (Δ S°), and free energy (Δ G°) of the reactions proposed.

  10. Effects of medium and trace metals on kinetics of carbon tetrachloride transformation by pseudomonas sp. strain KC

    SciTech Connect

    Tatara, G.M.; Dybas, M.J.; Criddle, C.S. )

    1993-07-01

    In recent years, interest has increased degradation of hazardous contaminants in situ by stimulating selected bacterial populations or by addition of novel organisms to contaminated sites. Advantages of introduced organisms include extensive study in the laboratory which improves prospects for control of their activities in the field. Chloroform (CF) is a common end product of carbon tetrachloride (CT) but is more presistant and is a suspected carcinogen. Metabolic pathways that do not produce CF are of interest. This study reports on the kinetics of CT transformation by Pseudomonas sp. strain KC and describes experiments to evaluate the role of trace metals in CT transformation kinetics. Evidence is provide that accelerated CT transformation can be obtained in iron-rich ground waters and soil slurries by adding strain KC after pH adjustment. 9 refs., 9 figs., 1 tab.

  11. [Immune homeostasis impairment in acute carbon tetrachloride intoxicated rats corrected by administration of tocopherol acetate and unithiol].

    PubMed

    Zabrodskiĭ, P F; Gromov, M S; Masliakov, V V

    2015-01-01

    The results of experiments on noninbred albino rats showed that the acute intoxication with carbon tetrachloride (CT) at a dose of 1 LD50 reduced the parameters of cellular immune response and function of Th1 cells more significantly than the levels of humoral immune response and Th2-lymphocyte function, decreases the blood content of immunoregulatory cytokines IFN-g, IL-2, IL-4 and anti-inflammatory cytokine IL-13, while not changing the concentration of anti-inflammatory cytokine IL-10 and increasing the concentration of pro-inflammatory cytokine IL-6. The application of unithiol, tocopherol acetate, and combinations partially restores the parameters examined. The combined effects of drugs during intoxication with CT does not exceed their separate action.

  12. Hydrodechlorination of Silicon Tetrachloride to Trichlorosilane Over Ordered Mesoporous Carbon Catalysts: Effect of Pretreatment of Oxygen and Hydrochloric Acid.

    PubMed

    Kwak, Do-Hwan; Akhtar, M Shaheer; Kim, Ji Man; Yang, O Bong

    2016-02-01

    This paper reports on the catalytic reaction for the conversion of silicon tetrachloride (STC) to trichlorosilane (TCS) over pretreated ordered mesoporous carbon (OMC) catalysts by oxygen (denoted as OMC-O2) and hydrochloric acid (denoted as OMC-HCl) at 300 degrees C under N2 atmosphere. The OMC-O2 shows significantly improved the surface area (1341.2 m2/g) and pore volume (1.65 cm3/g), which results in the highest conversion rate of 7.3% as compared to bare OMC (4.3%) and OMC-HCI (5.7%). It is found that the conversion rate of STC to TCS is proportional to the number of Si-O bond over OMC catalysts, which suggests that Si-O-C bond formation is crucial to the reaction as active sites. The O2 pretreatment seems to promote the generation of oxygenated species for the formation of Si-O-C. PMID:27433674

  13. Suppressive Effect of Kampo Formula "Juzen-taiho-to" on Carbon Tetrachloride-Induced Hepatotoxicity in Mice.

    PubMed

    Yoshioka, Hiroki; Fukaya, Shiori; Miura, Nobuhiko; Onosaka, Satomi; Nonogaki, Tsunemasa; Nagatsu, Akito

    2016-01-01

    The aim of the present study was to investigate whether pretreatment with the Japanese herbal medicine, "Juzen-taiho-to" (JTX), had an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.e., alanine aminotransferase and aspartate aminotransferase), lipid peroxidation, and hepatic Ca(2+) levels. Pretreatment with JTX recovered the CCl4-induced anorexia. In addition, JTX pretreatment decreased CCl4-induced plasma levels of hepatic injury markers. Increased Ca(2+) is a known indicator of the final progression to hepatocyte death, and CCl4-induced hepatotoxicity is mainly caused by oxidative stress. The present study indicated CCl4-induced lipid peroxidation and hepatic Ca(2+) content decreased with JTX pretreatment. Our results suggest that JTX has potential to protect of CCl4-induced anorexia, and the modulation of oxidative stress. PMID:27582337

  14. Effects of Ag(I), Au(III), and Cu(II) on the reductive dechlorination of carbon tetrachloride by green rust.

    PubMed

    O'Loughlin, Edward J; Kemner, Kenneth M; Burris, David R

    2003-07-01

    Green rusts (GRs), mixed iron(II)/iron(III) hydroxide minerals found in many suboxic environments, have been shown to reduce a range of organic and inorganic contaminants, including several chlorinated hydrocarbons. Many studies have demonstrated the catalytic activity of transition metal species in the reduction of chlorinated hydrocarbons, suggesting the potential for enhanced reduction by GR in the presence of an appropriate transition metal catalyst. Reductive dechlorination of carbon tetrachloride (CT) was examined in aqueous suspensions of GR amended with Ag(I), Au(III), or Cu(II). The CT reduction rates were greatly increased for systems amended with Cu(II), Au(III), and Ag(I) (listed in order of increasing rates) relative to GR alone. Observed intermediates and products included chloroform, dichloromethane, chloromethane, methane, acetylene, ethene, ethane, carbon monoxide, tetrachloroethene, and various nonchlorinated C3 and C4 compounds. Product distributions for the reductive dechlorination of CT were highly dependent on the transition metal used. A reaction pathway scheme is proposed in which CT is reduced primarily to methane and other nonchlorinated end products, largely through a series of one-electron reductions forming radicals and carbenes/carbenoids. Recently, X-ray absorption fine structure analysis of aqueous GR suspensions amended with Ag(I), Au(III), or Cu(II) showed that the metals were reduced to their zerovalent forms. A possible mechanism for CT reduction is the formation of a galvanic couple involving the zerovalent metal and GR, with reduction of CT occurring on the surface of the metal and GR serving as the bulk electron source. The enhanced reduction of CT by GR suspensions amended with Ag(I), Au(III), or Cu(II) may prove useful in the development of improved materials for remediation of chlorinated organic contaminants.

  15. Amelioration of carbon tetrachloride-induced hepatotoxicity and haemotoxicity by aqueous leaf extract of Cnidoscolus aconitifolius in rats.

    PubMed

    Saba, A B; Oyagbemi, A A; Azeez, O I

    2010-01-01

    This study was conducted to explore possible protective effect ofCnidoscolus aconitifolius (CA) leaf extract on carbon tetrachloride (CCl4)-induced hepatotoxicity and haemotoxicity in experimental animal models. Thirty six rats of six per group were used in this study. Group I received 10ml/kg normal saline as control. Group II-VI rats were administered with 1.25ml/kg body weight (bwt) of carbon tetrachloride intraperitonealy. Animals in groups III, IV, V and VI were however pre-treated with aqueous extract of Cnidoscolus aconitifolius at 100, 250, 500 and 750mg/kg body weight (bwt) respectively. Administration of CCL4 in untreated rats led to microcytic hypochromic anaemia, thrombocytopenia, increased erythrocyte fragility and stress induced leucocytosis accompanied with significant increase in neutrophils and decrease in lymphocyte counts. CCl4 also led to significant increase in serum transaminases (ALT and AST) and phosphatase (ALP) respectively compared with control animals. Also, CCL4 produced significant increase in serum blood urea nitrogen (BUN) and creatinine compared with normal rats. Pre-treatment with Cnidoscolus aconitifolius leaf extract brought about significant restoration of the haematological parameters to values that were comparable to those of the control with concomitant decrease in the activities of the marker of hepatic damage enzymes (ALT, AST and ALP), in a dose-dependent manner. Similarly, serum levels of blood urea nitrogen (BUN) and creatinine were also brought to near normal by the CA in a dose-dependent manner. From this study, we conclude that pre-exposure to Cnidoscolus aconitifolius leaf extract considerably reduced the effect of CCl4 on the blood parameters and ameliorated hepatic damage by the haloalkane. PMID:22314953

  16. Inhibition of MAPK and NF-κB signaling pathways alleviate carbon tetrachloride (CCl4)-induced liver fibrosis in Toll-like receptor 5 (TLR5) deficiency mice.

    PubMed

    Shu, Ming; Huang, Dan-dan; Hung, Zuo-an; Hu, Xiao-rong; Zhang, Shun

    2016-02-26

    Current researches showed that TLR family plays an important role in liver fibrosis, yet the molecular mechanism by which this occurs is not fully explained. In this study, we investigated the role of TLR5 in carbon tetrachloride-induced liver fibrosis, and further examined wether TLR5 knockout attenuated tetrachloride-induced liver fibrosis by inhibiting hepatic stellate cells activation via modulating NF-κB and MAPK signaling pathways. Our results found that carbon tetrachloride induced liver function injury in WT mice with a inflammatory responses through the activation of NF-κB and MAPK signaling pathways, resulting in hepatic stellate cells activation. In contrast, TLR5 deficiency mice after carbon tetrachloride administration reduced NF-κB and MAPK signaling pathways activation, which down regulated hepatic stellate cells activation. In addition, alpha smooth muscle-actin as marker of hepatic stellate cells further indicated that TLR5 knockout mice have a lower collagen accumulation in liver tissue than WT mice after carbon tetrachloride administration, resulting in inhibition of NF-κB and MAPK signaling pathways activation. Moreover, in vitro experiment of hepatic stellate cells challenged with LPS or TGF-β, further indicated that NF-κB and MAPK were involved in liver fibrosis development, leading to α-SMA expression and inflammation infiltration. However, cells from TLR5(-)(/-) may weaken phosphorylation levels of signal pathways, finally suppress progress of collagen accumulation and inflammatory responses. These results suggest a new therapeutic approach or target to protect against fibrosis caused by chronic liver diseases.

  17. Catalytic dechlorination of carbon tetrachloride in liquid phase with methanol as H-donor over Ag/C catalyst.

    PubMed

    Lu, Mohong; Li, Xuebing; Chen, Bo; Li, Mingshi; Xin, Hongchuan; Song, Liang

    2014-09-01

    Catalytic hydrodechlorination of carbon tetrachloride (CCl4) is an effective measure to remove CCl4 due to its pollutant character. The dechlorination of CCl4 to dichloromethane (CH2Cl2) and chloroform (CHCl3) with a molar ratio of 3:2 was catalyzed by carbon-supported silver (Ag/C) catalyst in methanol solution. It was proposed from the catalytic results and characterization (X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy) data that, the chloride ion is abstracted from adsorbed CCl4 by Ag to form CCl3 and CCI2 radicals and silver chloride (AgCl), and meanwhile the dehydrogenation of methanol over Ag domains intrigues initial active Ag-H species and formaldehyde (HCHO); then the CCI3 and CCI, radicals are combined with Ag-H to generate reaction products (CHCl3 and CH2Cl2) and Ag, and the dehydrogenated product HCHO facilitates the regeneration of formed AgCl to Ag with formation of carbon monoxide and hydrogen chloride. The catalyst can be recovered and recycled, and there was no significant decrease in catalytic activity and selectivity after 4th recycling. PMID:25924408

  18. Kinetics of 3H-thymidine label in rat liver regenerating after partial hepatectomy and after damage with carbon tetrachloride or silica.

    PubMed

    Kanta, J; Chmelar, V

    1989-01-01

    Rat liver DNA was labelled with [methyl-3H] thymidine after partial hepatectomy, carbon tetrachloride poisoning, or an intravenous injection of silica dust. Changes in DNA labelling were studied for 4 weeks after the single pulse. Total radioactivity incorporated into liver DNA after partial hepatectomy and after carbon tetrachloride administration remained on the same level when compared with that found after 1 h. DNA activity in liver of untreated rats and of rats treated with silica decreased by about 50% within the first 2 weeks and then remained on this level for the rest of the studied period. These differences may reflect the fact that hepatocytes that have a long life span are preferentially labelled in partially hepatectomized and CCl4-treated rats, while liver macrophages with a short half-life take up a large part of the label in intact rats and in rats treated with silica.

  19. Isobaric vapor liquid equilibria data for the binary system (glycidyl butyrate + acetone, glycidyl butyrate + carbon tetrachloride, glycidyl butyrate + chloroform) at atmospheric pressure 101 kPa

    NASA Astrophysics Data System (ADS)

    Huang, Qiang; Meng, Qingyi; Ban, Chunlan; Zhang, Rui; Gao, Yingyu

    2016-09-01

    Isobaric vapor liquid equilibria (VLE) for the binary mixtures of glycidyl butyrate(1) + acetone(2), glycidyl butyrate(1) + carbon tetrachloride(2) and glycidyl butyrate(1) + chloroform(2) at 101 kPa were studied. The experimental data were satisfactorily correlated with the models of Wilson, NRTL and UNIQUAC activity coefficients. The activity coefficients for the equilibrium data were obtained by the nonlinear least square method. The average relative deviations between experimental temperatures and calculated temperatures by the Wilson, NRTL and UNIQUAC models were 0.16, 0.16, 0.23% for glycidyl butyrate(1) + chloroform( 2), 0.38, 0.12, 0.27% for glycidylbutyrate(1) + carbon tetrachloride(2), and 0.67, 0.13, 0.54% for glycidyl butyrate(1) + acetone(2). Azeotrope behavior was not found for these systems. The thermodynamic consistency of the correlations was checked by the Herrington's area test.

  20. Work plan : targeted investigation to assess current conditions associated with the carbon tetrachloride plume downgradient from the former CCC/USDA facility at Milford, Nebraska.

    SciTech Connect

    LaFreniere, L. M.; Environmental Science Division

    2008-07-09

    The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility at Milford, Nebraska. In May 2008, the CCC/USDA directed the Environmental Science Division of Argonne National Laboratory, as its technical consultant, to develop a work plan for a targeted investigation at the Milford site. The purpose of the targeted investigation is to assess the current extent and configuration of the carbon tetrachloride plume downgradient from the former CCC/USDA facility and proximal to the banks of the Big Blue River, which borders the area of concern to the east, southeast, and northeast. In 1995, carbon tetrachloride contamination was detected by the Nebraska Department of Health and Human Services in a private drinking water well and a livestock well 1.25 mi south of Milford (Figure 1.1). The Trojan drinking water well is located directly downgradient (approximately 300 ft east) of the former CCC/USDA facility. Low levels of carbon tetrachloride contamination were also found in the Troyer livestock well, approximately 1,200 ft north of the former CCC/USDA facility.

  1. N-acetylcysteine protects against liver injure induced by carbon tetrachloride via activation of the Nrf2/HO-1 pathway.

    PubMed

    Cai, Zhaobin; Lou, Qi; Wang, Fugen; Li, Er; Sun, Jingjing; Fang, Hongying; Xi, Jianjun; Ju, Liping

    2015-01-01

    Chronic liver injury is an important clinical problem which eventually leads to cirrhosis, hepatocellular carcinoma and end-stage liver failure. It is well known that cell damage induced by reactive oxygen species (ROS) is an important mechanism of hepatocyte injure. N-acetylcysteine (NAC), a precursor of glutathione (GSH), is well-known role as the antidote to acetaminophen toxicity in clinic. NAC is now being utilized more widely in the clinical setting for non-acetaminophen (APAP) related causes of liver injure. However, the mechanisms underlying its beneficial effects are poorly defined. Thus, Aim of the present study was to investigate potential hepatic protective role of NAC and to delineate its mechanism of action against carbon tetrachloride (CCl4)-induced liver injury in models of rat. Our results showed that the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities as well as malondialdehyde (MDA) contents decreased significantly in CCl4-induced rats with NAC treatment. GSH content and superoxide dismutase (SOD) activities remarkably increased in the NAC groups compared with those in CCl4-induced group. Treatment with NAC had been shown to an increase in nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) mRNA levels. In conclusion, these results suggested that NAC upregulated HO-1 through the activation of Nrf2 pathway and protected rat against CCl4-induced liver injure. The results of this study provided pharmacological evidence to support the clinical application of NAC. PMID:26339453

  2. Antioxidant and protective effect of ethyl acetate extract of podophyllum hexandrum rhizome on carbon tetrachloride induced rat liver injury.

    PubMed

    Ganie, Showkat Ahmad; Haq, Ehtishamul; Masood, Akbar; Hamid, Abid; Zargar, Mohmmad Afzal

    2011-01-01

    The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Superoxide radical scavenging activity, Hydrogen peroxide radical scavenging activity and its Reducing power ability. All these in vitro antioxidant activities were concentration dependent which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride (CCl(4))-induced liver damage. Pre-treated rats were given ethyl acetate extract at 20, 30 and 50 mg/kg dose prior to CCl(4) administration (1 ml/kg, 1:1 in olive oil). Rats pre-treated with Podophyllum hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl(4)-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione-S- transferase) significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver protective effect against CCl(4)-induced hepatotoxicity and possess in vitro antioxidant activities.

  3. Protective effect of apricot (Prunus armeniaca L.) on hepatic steatosis and damage induced by carbon tetrachloride in Wistar rats.

    PubMed

    Ozturk, Feral; Gul, Mehmet; Ates, Burhan; Ozturk, I Cetin; Cetin, Asli; Vardi, Nigar; Otlu, Ali; Yilmaz, Ismet

    2009-12-01

    The present study was planned to investigate the protective effect of 10 % and 20 % apricot-containing feed on carbon tetrachloride (CCl4)-induced hepatic steatosis and damage. Adult male Wistar rats (n 42) were divided into six groups of seven each, as follows: control group; CCl4 group; CCl4+10 % apricot group; CCl4+20 % apricot group; 10 % apricot group; 20 % apricot group. All apricot groups were fed with 10 % or 20 % apricot-containing feed for 5 months. CCl4 injections were applied to the CCl4 groups at the dose of 1 mg/kg for 3 d at the end of 5 months. In the CCl4 group, vacuolated hepatocytes and hepatic necrosis were seen, especially in the centrilobular area. Hepatocytes showed an oedematous cytoplasmic matrix, large lipid globules and degenerated organelles. The area of liver injury was found significantly decreased with apricot feeding. Malondialdehyde and total glutathione levels and catalase, superoxide dismutase and glutathione peroxidase activities were significantly changed in the CCl4 group and indicated increased oxidative stress. Apricot feeding decreased this oxidative stress and ameliorated histological damage. We concluded that apricot feeding had beneficial effects on CCl4-induced liver steatosis and damage probably due to its antioxidant nutrient (beta-carotene and vitamin) contents and high radical-scavenging capacity. Dietary intake of apricot can reduce the risk of liver steatosis and damage caused by free radicals.

  4. Contribution and Mobilization of Mesenchymal Stem Cells in a mouse model of carbon tetrachloride-induced liver fibrosis.

    PubMed

    Liu, Yan; Yang, Xue; Jing, Yingying; Zhang, Shanshan; Zong, Chen; Jiang, Jinghua; Sun, Kai; Li, Rong; Gao, Lu; Zhao, Xue; Wu, Dong; Shi, Yufang; Han, Zhipeng; Wei, Lixin

    2015-01-01

    Hepatic fibrosis is associated with bone marrow derived mesenchymal stem cells (BM-MSCs). In this study, we aimed to determine what role MSCs play in the process and how they mobilize from bone marrow (BM). We employed a mouse model of carbon tetrachloride(CCl4)-induced liver fibrosis. Frozen section was used to detect MSCs recruited to mice and human fibrotic liver. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was detected to assess liver function. It was found that MSCs of both exogenous and endogenous origin could aggravate liver fibrosis and attenuate liver damage as indicated by lower serum ALT and AST levels. Stromal cell-derived factor-1 (SDF-1α)/ CXCR4 was the most important chemotactic axis regulating MSCs migration from BM to fibrotic liver. Frozen section results showed that the migration did not start from the beginning of liver injury but occurred when the expression balance of SDF-1α between liver and BM was disrupted, where SDF-1α expression in liver was higher than that in BM. Our findings provide further evidence to show the role of BM-MSCs in liver fibrosis and to elucidate the mechanism underlying MSCs mobilization in our early liver fibrosis mice model induced by CCl4. PMID:26643997

  5. Antioxidant and Protective Effect of Ethyl Acetate Extract of Podophyllum Hexandrum Rhizome on Carbon Tetrachloride Induced Rat Liver Injury

    PubMed Central

    Ganie, Showkat Ahmad; Haq, Ehtishamul; Masood, Akbar; Hamid, Abid; Zargar, Mohmmad Afzal

    2011-01-01

    The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Superoxide radical scavenging activity, Hydrogen peroxide radical scavenging activity and its Reducing power ability. All these in vitro antioxidant activities were concentration dependent which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride (CCl4)-induced liver damage. Pre-treated rats were given ethyl acetate extract at 20, 30 and 50 mg/kg dose prior to CCl4 administration (1 ml/kg, 1:1 in olive oil). Rats pre-treated with Podophyllum hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl4-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione-S- transferase) significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver protective effect against CCl4-induced hepatotoxicity and possess in vitro antioxidant activities. PMID:21394192

  6. Protective effects of Chaenomeles thibetica extract against carbon tetrachloride-induced damage via the MAPK/Nrf2 pathway.

    PubMed

    Ma, Bingxin; Wang, Jing; Tong, Jing; Zhou, Gao; Chen, Yuxin; He, Jingsheng; Wang, Youwei

    2016-03-01

    Chaenomeles thibetica, a type of fruit of the genus Chaenomeles, is commonly cultivated and used as Mugua in China and as liquor, candy, and functional food in Tibet. Total phenol, flavonoid, and proanthocyanidin contents were measured in C. thibetica extract (CTE). CTE had a positive effect on free radical scavenging and anti-lipid oxidation in vitro. The protective effects of CTE against carbon tetrachloride (CCl4)-induced oxidative damage in vivo were also measured. The results of antioxidative enzymes indicated that CTE can increase the activities of the catalase, superoxide dismutase, and glutathione contents and reduce the level of malondialdehyde in rats. The levels of alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and total bilirubin were significantly reversed by CTE compared with the elevated levels in the CCl4 group. Besides, CTE could reverse the cell viability of HepG2 inoculated with CCl4via phosphorylation of mitogen-activated protein kinases (MAPKs), activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and increasing the expression of phase II detoxification enzymes. These effects may expand the applications of C. thibetica and offer alternative food with antioxidant and hepatoprotective functions in the food industry. PMID:26882870

  7. Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses.

    PubMed

    Hu, Lei; Montzka, Stephen A; Miller, Ben R; Andrews, Arlyn E; Miller, John B; Lehman, Scott J; Sweeney, Colm; Miller, Scot M; Thoning, Kirk; Siso, Carolina; Atlas, Elliot L; Blake, Donald R; de Gouw, Joost; Gilman, Jessica B; Dutton, Geoff; Elkins, James W; Hall, Bradley; Chen, Huilin; Fischer, Marc L; Mountain, Marikate E; Nehrkorn, Thomas; Biraud, Sebastien C; Moore, Fred L; Tans, Pieter

    2016-03-15

    National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration's flask air sampling network. We estimate an annual average US emission of 4.0 (2.0-6.5) Gg CCl4 y(-1) during 2008-2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y(-1)) but only 8% (3-22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008-2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

  8. Ameliorating effect of pomegranate juice consumption on carbon tetrachloride-induced sperm damages, lipid peroxidation, and testicular apoptosis.

    PubMed

    Türk, Gaffari; Çeribaşı, Songül; Sönmez, Mustafa; Çiftçi, Mehmet; Yüce, Abdurrauf; Güvenç, Mehmet; Kaya, Şeyma Özer; Çay, Mehmet; Aksakal, Mesut

    2016-01-01

    The aim of this study was to investigate whether pomegranate juice (PJ) consumption has an ameliorating effect on carbon tetrachloride (CCl4)-induced sperm damages and testicular apoptosis associated with the oxidative stress in male rats. The study comprised of four groups (groups 1-4). Group 1 received olive oil + distilled water daily; group 2 was treated with 5 ml/kg PJ + olive oil daily; group 3 was treated with 0.25 ml/kg CCl4 dissolved in olive oil, weekly + distilled water daily; and group 4 received weekly CCl4 + daily PJ. All administrations were performed by gavage and maintained for 10 weeks. CCl4 administration caused significant decreases in body and reproductive organ weights, sperm motility, concentration and testicular catalase activity, significant increases in malondialdehyde (MDA) level, and abnormal sperm rate and apoptotic index along with some histopathological damages when compared with the control group. However, significant ameliorations were observed in absolute weights of testis and epididymis, all sperm quality parameters, MDA level, apoptotic index, and testicular histopathological structure following the administration of CCl4 together with PJ when compared with group given CCl4 only. In conclusion, PJ consumption ameliorates the CCl4-induced damages in male reproductive organs and cells by decreasing the lipid peroxidation.

  9. Effect of ethanol, carbon tetrachloride, and methyl ethyl ketone on butanol oxidase activity in rat lung and liver

    SciTech Connect

    Carlson, G.P. )

    1989-01-01

    Tha ability of the rat liver to oxidize 2-butanol via a cytochrome P-450-mediated mixed-function oxidase reaction is well known. The purpose of this study was to examine this microsomal alcohol oxidizing system in rat lung and determine if it could be altered by treatments that inhibit or induce this activity. 2-Butanol was incubated with microsomal preparations from male rats, and methyl ethyl ketone production was measured by gas chromatography. The rate was six to eight times lower in lung than in liver. Administration of low doses of ethanol (0.5 ml/kg and 1.0 ml/kg) ip for 7 d did not alter activity in the liver but was inhibitory in the lung, as was a high dose of 3.0 ml/kg in the liver. Carbon tetrachloride (1.0 ml/kg, ip) decreased activity in both tissues, especially the lung. The effects of the two inhibitors were not additive. Methyl ethyl ketone induced 2-butanol oxidation in both tissues. The lung possesses butanol oxidase activity that is alterable by both inhibitors and inducers.

  10. Toxicological and biochemical studies on Schinus terebinthifolius concerning its curative and hepatoprotective effects against carbon tetrachloride-induced liver injury

    PubMed Central

    Abdou, Rania H.; Saleh, Sherif Y.; Khalil, Waleed F.

    2015-01-01

    Background: Recently, many efforts have been made to discover new products of natural origin which can limit the xenobiotic-induced hepatic injury. Carbon tetrachloride (CCl4) is a highly toxic chemical that is widely used to study hepatotoxicity in animal models. Objective: The present study was conducted to investigate the curative and protective effects of Schinus terbenthifolius ethanolic extract against CCl4 -induced acute hepatotoxicity in rats. Materials and Methods: S. terbenthifolius extract was orally administered in a dose of 350 mg dried extract/kg b.wt. before and after intoxication with CCl4 for curative and protective experiments, respectively. A group of hepatotoxicity indicative enzymes, oxidant-antioxidant capacity, DNA oxidation, and apoptosis markers were measured. Results: CCl4 increased liver enzyme leakage, oxidative stress, hepatic apoptosis, DNA oxidation, and inflammatory markers. Administration of S. terebinthifolius, either before or after CCl4 intoxication, significantly decreased elevated serum liver enzymes and reinstated the antioxidant capacity. Interestingly, S. terebinthifolius extract inhibited hepatocyte apoptosis as revealed by approximately 20 times down-regulation in caspase-3 expression when compared to CCl4 untreated group. On the other hand, there was neither protective nor curative effect of S. terebinthifolius against DNA damage caused by CCl4. Conclusion: The present study suggests that S. terebinthifolius extract could be a substantially promising hepatoprotective agent against CCl4 toxic effects and may be against other hepatotoxic chemical or drugs. PMID:26109780

  11. Effects of Lawsonia inermis L. (Henna) leaves’ methanolic extract on carbon tetrachloride-induced hepatotoxicity in rats

    PubMed Central

    Mohamed, Musab Awad; Eldin, Imad Mohamed Taj; Mohammed, Abd-Elwahab Hassan; Hassan, Hozeifa Mohamed

    2016-01-01

    Background: Natural products with therapeutic properties such as plants, minerals, and animal products, for many years, were the main sources of drugs for the treatment of numerous diseases; hence selection of Lawsonia inermis L. (Henna) to study its hepatoprotective activity was considered. Objectives: This was an attempt to evaluate the hepatoprotective effect of L. inermis leaves’ methanolic extract on carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Materials and Methods: The L. inermis leaves’ methanolic extract, which obtained by maceration, was orally administered in doses of 100 mg/kg and 200 mg/kg to the tested animals to assess its effects on serum levels of hepatotoxicity parameters, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, and total proteins along with histopathological liver sections examination, while silymarin (25 mg/kg), a potent hepatoprotective drug, was used as standard control. Results: The two doses of the plant extract showed dose-dependent hepatoprotective effect, as evident by the significant reduction (P < 0.05) in serum levels of AST, ALT, ALP, and bilirubin along with the improvement in histopathological liver sections compared to CCl4-only treated animals. Conclusion: As experimentally evident, it could be concluded that this plant material could provide a hepatoprotective effect that could be attributed to its antioxidant properties. PMID:27069719

  12. Pulmonary retention and tissue distribution of {sup 239}Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.; Nikula, K.J.

    1994-11-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl{sub 4} and plutonium compounds. Potential for future exposure exists during {open_quotes}cleanup{close_quotes} operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl{sub 4} is 5 ppm; however, concentrations of CCl{sub 4} occurring in the nuclear weapons facilities over the past 40-50 y are unknown and may have exceeded this value. The pilot study described in this report is designed to determine whether subchronic inhalation of CCl{sub 4} by CDF{sup register}(F-344)/CrlBR rats and Syrian golden hamsters, at concentrations expected to produce some histologic changes in liver, alters the hepatic retention and toxic effects of inhaled {sup 239}Pu nitrate {sup 239}Pu(NO{sub 3}){sub 4}.

  13. Probing the Interaction of Amorphous Solid Water on a Hydrophobic Surface: Dewetting and Crystallization Kinetics of ASW on Carbon Tetrachloride

    SciTech Connect

    May, Robert A.; Smith, R. Scott; Kay, Bruce D.

    2011-11-28

    Desorption of carbon tetrachloride from beneath an amorphous solid water (ASW) overlayer is explored utilizing a combination of temperature programmed desorption and infrared spectroscopy. Otherwise inaccessible information about the dewetting and crystallization of ASW is revealed by monitoring desorption of the CCl4 underlayer. The desorption maximum of CCl4 on graphene occurs at ~140 K. When ASW wets the CCl4 no desorption below 140 K is observed. However, the mobility of the water molecules increases with ASW deposition temperature, leading to a thermodynamically driven dewetting of water from the hydrophobic CCl4 surface. This dewetting exposes some CCl4 to the ambient environment, allowing unhindered desorption of CCl4 below 140 K. When ASW completely covers the underlayer, desorption of CCl4 is delayed until crystallization induced cracking of the ASW overlayer opens an escape path to the surface. The subsequent rapid episodic release of CCl4 is termed a “molecular volcano”. Reflection adsorption infrared spectroscopy (RAIRS) measurements indicate that the onset and duration of the molecular volcano is directly controlled by the ASW crystallization kinetics.

  14. Antioxidant Effects of Bone Marrow Mesenchymal Stem Cell against Carbon Tetrachloride-Induced Oxidative Damage in Rat Livers

    PubMed Central

    Ayatollahi, M.; Hesami, Z.; Jamshidzadeh, A.; Gramizadeh, B.

    2014-01-01

    Background: Liver fibrosis results from excessive accumulation of extracellular matrix, which affects liver function over time and leads to its failure. In the past, liver transplant was thought to be the only treatment for end-stage liver disease, but due to the shortage of proper donors other medical treatments have been taken into consideration. Objective: To evaluate the therapeutic effects of bone marrow derived mesenchymal stem cells (BM-MSC) in CCl4 damaged rats. Methods: Liver damage in adult male Wistar rats was induced with carbon tetrachloride (CCl4). The rats were divided into normal control group, receiving CCl4, and those receiving CCl4 + marrow derived-MSC. Human BM-MSC was isolated, cultured, and characterized. The rats were injected with xenograft MSCs into the hepatic lobes of the liver. In the eighth week, blood samples were taken from all groups. Histological examination and biochemical analyses were used to compare the morphological and functional liver regeneration among different groups. Measurement of lipid peroxidation and glutathione transferase activity was also performed. Results: Histopathology and biochemical analyses indicated that local injection of human BM-MSCs was effective in treating liver failure in the rat model. Furthermore, oxidative stress was attenuated by increased level of GSH content after MSC transplantation. Conclusion: Evidence of this animal model approach showed that bone marrow-derived MSCs promote an antioxidant response and support the potential of using MSCs transplantation as an effective treatment modality for liver disease. PMID:25426285

  15. Therapeutic detoxification of quercetin against carbon tetrachloride-induced acute liver injury in mice and its mechanism*

    PubMed Central

    Zhang, Jia-qi; Shi, Liang; Xu, Xi-ning; Huang, Si-chong; Lu, Bin; Ji, Li-li; Wang, Zheng-tao

    2014-01-01

    This study observes the therapeutic detoxification of quercetin, a well-known flavonoid, against carbon tetrachloride (CCl4) induced acute liver injury in vivo and explores its mechanism. Quercetin decreased CCl4-increased serum activities of alanine and aspartate aminotransferases (ALT/AST) when orally taken 30 min after CCl4 intoxication. The results of a histological evaluation further evidenced the ability of quercetin to protect against CCl4-induced liver injury. Quercetin decreased the CCl4-increased malondialdehyde (MDA) and reduced the glutathione (GSH) amounts in the liver. It also reduced the enhanced immunohistochemical staining of the 4-hydroxynonenal (4-HNE) in the liver induced by CCl4. Peroxiredoxin (Prx) 1, 2, 3, 5, 6, thioredoxin reductase 1 and 2 (TrxR1/2), thioredoxin 1 and 2 (Trx1/2), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) all play critical roles in maintaining cellular redox homeostasis. Real-time polymerase chain reaction (PCR) results demonstrated that quercetin reversed the decreased mRNA expression of all those genes induced by CCl4. In conclusion, our results demonstrate that quercetin ameliorates CCl4-induced acute liver injury in vivo via alleviating oxidative stress injuries when orally taken after CCl4 intoxication. This protection may be caused by the elevation of the antioxidant capacity induced by quercetin. PMID:25471833

  16. Sympathetic Nervous System Control of Carbon Tetrachloride-Induced Oxidative Stress in Liver through α-Adrenergic Signaling.

    PubMed

    Lin, Jung-Chun; Peng, Yi-Jen; Wang, Shih-Yu; Lai, Mei-Ju; Young, Ton-Ho; Salter, Donald M; Lee, Herng-Sheng

    2016-01-01

    In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS) in modulating the hepatic response to oxidative stress. Our aim was to investigate the role of the SNS in healthy and oxidatively stressed liver parenchyma. Mice treated with 6-hydroxydopamine hydrobromide were used to realize chemical sympathectomy. Carbon tetrachloride (CCl4) injection was used to induce oxidative liver injury. Sympathectomized animals were protected from CCl4 induced hepatic lipid peroxidation-mediated cytotoxicity and genotoxicity as assessed by 4-hydroxy-2-nonenal levels, morphological features of cell damage, and DNA oxidative damage. Furthermore, sympathectomy modulated hepatic inflammatory response induced by CCl4-mediated lipid peroxidation. CCl4 induced lipid peroxidation and hepatotoxicity were suppressed by administration of an α-adrenergic antagonist. We conclude that the SNS provides a permissive microenvironment for hepatic oxidative stress indicating the possibility that targeting the hepatic α-adrenergic signaling could be a viable strategy for improving outcomes in patients with acute hepatic injury.

  17. Doxazosin Treatment Attenuates Carbon Tetrachloride-Induced Liver Fibrosis in Hamsters through a Decrease in Transforming Growth Factor β Secretion

    PubMed Central

    Muñoz-Ortega, Martin Humberto; Llamas-Ramírez, Raúl Wiliberto; Romero-Delgadillo, Norma Isabel; Elías-Flores, Tania Guadalupe; de Jesus Tavares-Rodríguez, Edgar; del Rosario Campos-Esparza, María; Cervantes-García, Daniel; Muñoz-Fernández, Luis; Gerardo-Rodríguez, Martin; Ventura-Juárez, Javier

    2016-01-01

    Background/Aims The development of therapeutic strategies for the treatment of cirrhosis has become an important focus for basic and clinical researchers. Adrenergic receptor antagonists have been evaluated as antifibrotic drugs in rodent models of carbon tetrachloride (CCl4)-induced cirrhosis. The aim of the present study was to evaluate the effects of carvedilol and doxazosin on fibrosis/cirrhosis in a hamster animal model. Methods Cirrhotic-induced hamsters were treated by daily administration of carvedilol and doxazosin for 6 weeks. Hepatic function and histological evaluation were conducted by measuring biochemical markers, including total bilirubin, aspartate aminotransferase, alanine aminotransferase and albumin, and liver tissue slices. Additionally, transforming growth factor β (TGF-β) immunohistochemistry was analyzed. Results Biochemical markers revealed that hepatic function was restored after treatment with doxazosin and carvedilol. Histological evaluation showed a decrease in collagen type I deposits and TGF-β-secreting cells. Conclusions Taken together, these results suggest that the decrease in collagen type I following treatment with doxazosin or carvedilol is achieved by decreasing the profibrotic activities of TGF-β via the blockage of α1- and β-adrenergic receptor. Consequently, a diminution of fibrotic tissue in the CCl4-induced model of cirrhosis is achieved. PMID:26573293

  18. Antioxidant potential of Cymbopogon citratus extract: alleviation of carbon tetrachloride-induced hepatic oxidative stress and toxicity.

    PubMed

    Koh, Pei Hoon; Mokhtar, Ruzaidi Azli Mohd; Iqbal, Mohammad

    2012-01-01

    This study was aimed to evaluate the effect of Cymbopogon citratus against carbon tetrachloride (CCl(4))-mediated hepatic oxidative damage in rats. Rats were administrated with C. citratus extract (100, 200 and 300 mg/kg b.w.) for 14 days before the challenge of CCl(4) (1.2 ml/kg b.w. p.o) on 13th and 14th days. Hepatic damage was evaluated by employing serum biochemical parameters (alanine aminotransferase-ALT, aspartate aminotransferase-AST and lactate dehydrogenase-LDH), malondialdehye (MDA) level, reduced GSH and antioxidant enzymes (catalase: CAT, glutathione peroxidase: GPX, quinone reductase: QR, glutathione S-transferase: GST, glutathione reductase: GR, glucose-6-phosphate dehyrogenase: G6PD). In addition, CCl(4)-mediated hepatic damage was further evaluated by histopathological examination. However, most of these changes were alleviated by prophylactic treatment of animals with C. citratus dose dependently (p < 0.05). The protection was further evident through decreased histopathological alterations in liver. The results of the present study indicated that the hepatoprotective effect of C. citratus might be ascribable to its antioxidant and free radical scavenging property.

  19. Antihepatotoxic effect of marrubium vulgare and withania somnifera extracts on carbon tetrachloride-induced hepatotoxicity in rats.

    PubMed

    Elberry, Ahmed A; Harraz, Fathalla M; Ghareib, Salah A; Nagy, Ayman A; Gabr, Salah A; Suliaman, Mansour I; Abdel-Sattar, Essam

    2010-09-01

    Marrubium vulgare and Withania somnifera are used in folk medicine of several countries. Many researches showed that they are used for the treatment of variety of diseases due to their antioxidant effects. The present aim of this study was to evaluate the antihepatotoxic and antioxidant activities of the both extracts against carbon tetrachloride (CCl4)-induced hepatic damage in rats. Both extracts were given orally in a dose of 500 mg/kg/day for 4 weeks along with CCl4 started at the 7th week of induction of hepatotoxicity. The antihepatotoxic activity was assessed by measuring aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), tissue content and malondialdehyde (MDA) as well as histopathological examination. Both extracts showed a significant antihepatotoxic effect by reducing significantly the levels of AST, ALT and LDH. However, ALP levels were decreased non-significantly. Regarding the antioxidant activity, they exhibited significant effects by increasing the GPx, GR and GST activities with increased GSH tissue contents and decreased production of MDA level. Furthermore, both extracts alleviated histopathological changes in rats' liver treated with CCl4. M. vulgare and W. somnifera protect the rats' liver against CCl4-induced hepatotoxicity. This effect may be attributed, at least in part, to the antioxidant activities of these extracts.

  20. ANTIHEPATOTOXIC EFFECT OF MARRUBIUM VULGARE AND WITHANIA SOMNIFERA EXTRACTS ON CARBON TETRACHLORIDE-INDUCED HEPATOTOXICITY IN RATS

    PubMed Central

    Elberry, Ahmed A.; Harraz, Fathalla M.; Ghareib, Salah A.; Nagy, Ayman A.; Gabr, Salah A.; Suliaman, Mansour I.; Abdel-Sattar, Essam

    2010-01-01

    Marrubium vulgare and Withania somnifera are used in folk medicine of several countries. Many researches showed that they are used for the treatment of variety of diseases due to their antioxidant effects. The present aim of this study was to evaluate the antihepatotoxic and antioxidant activities of the both extracts against carbon tetrachloride (CCl4)-induced hepatic damage in rats. Both extracts were given orally in a dose of 500 mg/kg/day for 4 weeks along with CCl4 started at the 7th week of induction of hepatotoxicity. The antihepatotoxic activity was assessed by measuring aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), tissue content and malondialdehyde (MDA) as well as histopathological examination. Both extracts showed a significant antihepatotoxic effect by reducing significantly the levels of AST, ALT and LDH. However, ALP levels were decreased non-significantly. Regarding the antioxidant activity, they exhibited significant effects by increasing the GPx, GR and GST activities with increased GSH tissue contents and decreased production of MDA level. Furthermore, both extracts alleviated histopathological changes in rats’ liver treated with CCl4. M. vulgare and W. somnifera protect the rats’ liver against CCl4-induced hepatotoxicity. This effect may be attributed, at least in part, to the antioxidant activities of these extracts. PMID:24825994

  1. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Xiao, X.; Prinn, R. G.; Fraser, P. J.; Weiss, R. F.; Simmonds, P. G.; O'Doherty, S.; Miller, B. R.; Salameh, P. K.; Harth, C. M.; Krummel, P. B.; Golombek, A.; Porter, L. W.; Butler, J. H.; Elkins, J. W.; Dutton, G. S.; Hall, B. D.; Steele, L. P.; Wang, R. H. J.; Cunnold, D. M.

    2010-11-01

    Carbon tetrachloride (CCl4) has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CCl4 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996-2004. The Model of Atmospheric Transport and Chemistry (MATCH), driven by offline National Center for Environmental Prediction (NCEP) reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions.

  2. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Xiao, X.; Prinn, R. G.; Fraser, P. J.; Weiss, R. F.; Simmonds, P. G.; O'Doherty, S.; Miller, B. R.; Salameh, P. K.; Harth, C. M.; Krummel, P. B.; Golombek, A.; Porter, L. W.; Elkins, J. W.; Dutton, G. S.; Hall, B. D.; Steele, L. P.; Wang, R. H. J.; Cunnold, D. M.

    2010-05-01

    Carbon tetrachloride (CCl4) has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CC14 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996-2004. The Model of Atmospheric Transport and Chemistry (MATCH), driven by offline National Center for Environmental Prediction (NCEP) reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and NOAA Earth System Research Laboratory (ESRL) and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions.

  3. Antioxidant activity of extract and its major constituents from okra seed on rat hepatocytes injured by carbon tetrachloride.

    PubMed

    Hu, Lianmei; Yu, Wenlan; Li, Ying; Prasad, Nagendra; Tang, Zhaoxin

    2014-01-01

    The antioxidant activities and protective effects of total phenolic extracts (TPE) and their major components from okra seeds on oxidative stress induced by carbon tetrachloride (CCl4) in rat hepatocyte cell line were investigated. The major phenolic compounds were identified as quercetin 3-O-glucosyl (1 → 6) glucoside (QDG) and quercetin 3-O-glucoside (QG). TPE, QG, and QDG from okra seeds exhibited excellent reducing power and free radical scavenging capabilities including α, α-diphenyl-β-picrylhydrazyl (DPPH), superoxide anions, and hydroxyl radical. Overall, DPPH radical scavenging activity and reducing power of QG and QDG were higher than those of TPE while superoxide and hydroxyl radical scavenging activities of QG and TPE were higher than those of QDG. Furthermore, TPE, QG, and QDG pretreatments significantly alleviated the cytotoxicity of CCl4 on rat hepatocytes, with attenuated lipid peroxidation, increased SOD and CAT activities, and decreased GPT and GOT activities. The protective effects of TPE and QG on rat hepatocytes were stronger than those of QDG. However, the cytotoxicity of CCl4 on rat hepatocytes was not affected by TPE, QG, and QDG posttreatments. It was suggested that the protective effects of TPE, QG, and QDG on rat hepatocyte against oxidative stress were related to the direct antioxidant capabilities and the induced antioxidant enzymes activities. PMID:24719856

  4. Protective Effect of the Total Saponins from Rosa laevigata Michx Fruit against Carbon Tetrachloride-Induced Liver Fibrosis in Rats.

    PubMed

    Dong, Deshi; Yin, Lianhong; Qi, Yan; Xu, Lina; Peng, Jinyong

    2015-06-01

    In this study, the protective effect of the total saponins from Rosa laevigata Michx (RLTS) against liver fibrosis induced by carbon tetrachloride (CCl4) in rats was evaluated. The results showed that RLTS significantly rehabilitated the levels of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, glutathione, glutathione peroxidase, catalase, superoxide dismutase, hydroxyproline, α-smooth muscle actin, collagen I, collagen III and fibronectin, which were confirmed using H&E, Sirius Red and Masson histopathological assays. Further research indicated that RLTS markedly reduced cytochrome P450 2E1 activity, attenuated oxidative stress, and suppressed inflammation. In addition, RLTS facilitated matrix degradation through down-regulation of matrix metalloproteinase2, matrix metalloproteinase 9 and metalloproteinases1, and exerted the anti-fibrotic effects through affecting transforming growth factor β/Smad, focal adhesion kinase/phosphatidylinositol-3-kinase/amino kinase terminal/70-kDa ribosomal S6 Kinase (FAK-PI3K-Akt-p70(S6K)) and mitogen-activated protein kinase (MAPK) signaling pathways. Taken together, our data indicate that RLTS can be applied as one effective candidate for the treatment of liver fibrosis in the future.

  5. Reconnaissance survey for lightweight and carbon tetrachloride extractable hydrocarbons in the central and eastern basins of Lake Erie: September 1978

    SciTech Connect

    Zapotosky, J.E.; White, W.S.

    1980-10-01

    A reconnaissance survey of the central and eastern basins of Lake Erie (22,240 km/sup 2/) was conducted from September 17 to 27, 1978. The survey provided baseline information on natural gas and oil losses from geologic formations, prior to any potential development of natural gas resources beneath the United States portion of the Lake. Lightweight hydrocarbons indicative of natural gas (methane, ethane, propane, isobutane, and n-butane) are introduced into the waters of Lake Erie by escape from geologic formations and by biological/photochemical processes. The geochemical exploration technique of hydrocarbon sniffing provided enough data to reveal significant distribution patterns, approximate concentrations, and potential sources. Twelve sites with elevated lightweight hydrocarbon concentrations had a composition similar to natural gas. In one area of natural gas input, data analysis suggested a potential negative effect of natural gas on phytoplanktonic metabolism (i.e., ethylene concentration). Samples taken for liquid hydrocarbon analysis (carbon tetrachloride extractable hydrocarbons) correlated best with biologically derived lightweight hydrocarbons.

  6. Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses

    NASA Astrophysics Data System (ADS)

    Hu, Lei; Montzka, Stephen A.; Miller, Ben R.; Andrews, Arlyn E.; Miller, John B.; Lehman, Scott J.; Sweeney, Colm; Miller, Scot M.; Thoning, Kirk; Siso, Carolina; Atlas, Elliot L.; Blake, Donald R.; de Gouw, Joost; Gilman, Jessica B.; Dutton, Geoff; Elkins, James W.; Hall, Bradley; Chen, Huilin; Fischer, Marc L.; Mountain, Marikate E.; Nehrkorn, Thomas; Biraud, Sebastien C.; Moore, Fred L.; Tans, Pieter

    2016-03-01

    National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration's flask air sampling network. We estimate an annual average US emission of 4.0 (2.0-6.5) Gg CCl4 y-1 during 2008-2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y-1) but only 8% (3-22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008-2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

  7. Hepatoprotective potential of Decalepis hamiltonii (Wight and Arn) against carbon tetrachloride-induced hepatic damage in rats.

    PubMed

    Harish, R; Shivanandappa, T

    2010-10-01

    Hepatoprotective activity of the roots of Decalepis hamiltonii (Wight and Arn) was studied using carbon tetrachloride (CCl(4)) induced liver injury model in albino rats. The hepatotoxicity produced by acute CCl(4) administration was found to be inhibited by pretreating the rats with crude methanolic extract of the roots of D. hamiltonii (Dh) prior to CCl(4) induction. Hepatotoxic inhibition was measured with the decreased levels of hepatic serum marker enzymes (glutamate-pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) and lipid peroxide formation. Imbalance level of glutathione (GSH) and antioxidant enzymes such as catalase, glutathione peroxidase, and glutathione reductase were normalized in rats pretreated with Dh extract followed by CCl(4) administration. Pathological changes of hepatic lesions caused by CCl(4) were also improved by pretreatment with the Dh root extract. The results of this study indicate that roots of D. hamiltonii could afford a significant protective action in the alleviation of CCl(4)-induced hepatic damage in rats.

  8. Duration-dependent hepatoprotective effects of propolis extract against carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Bhadauria, Monika; Nirala, Satendra Kumar; Shukla, Sangeeta

    2007-01-01

    Propolis is a natural product produced by bees that was discovered through the study of traditional cures and knowledge of indigenous people throughout the world. It is rich in vitamins A, B, C, and E, and in amino acids, copper, iron, manganese, and zinc. The investigators studied the duration-dependent hepatoprotective effects of propolis extract (200 mg/kg, orally) against carbon tetrachloride (CCl 4; 1.5 mL/kg, intraperitoneally)-induced liver damage in rats. Administration of CCl 4 caused a sharp elevation in the activity of serum transaminases and serum alkaline phosphatase. A significant depletion in hepatically reduced glutathione was observed with significantly enhanced hepatic lipid peroxidation. After CCl 4 administration, glycogen contents and activities of alkaline phosphatase, adenosine triphosphatase, and succinic dehydrogenase were significantly decreased, whereas total protein contents and activity of acid phosphatase were increased in the liver and kidney. Propolis extract reversed alterations in all parameters when administered within 6, 12, and 24 h of toxicant exposure. Propolis therapy produced duration-dependent protection, with maximal protection achieved at 24 h after CCl 4 exposure. It is believed that propolis in its natural form has general pharmacologic value and marked hepatoprotective potential because of its composition of minerals, flavonoids, and phenolic compounds. PMID:18029340

  9. Comparative study on the inhibitory effects of antioxidant vitamins and radon on carbon tetrachloride-induced hepatopathy.

    PubMed

    Kataoka, Takahiro; Nishiyama, Yuichi; Yamato, Keiko; Teraoka, Junichi; Morii, Yuji; Sakoda, Akihiro; Ishimori, Yuu; Taguchi, Takehito; Yamaoka, Kiyonori

    2012-11-01

    We have previously reported that radon inhalation activates anti-oxidative functions and inhibits carbon tetrachloride (CCl(4))-induced hepatopathy. It has also been reported that antioxidant vitamins can inhibit CCl(4)-induced hepatopathy. In the current study, we examined the comparative efficacy of treatment with radon, ascorbic acid and α-tocopherol on CCl(4)-induced hepatopathy. Mice were subjected to intraperitoneal injection of CCl(4) after inhaling approximately 1000 or 2000 Bq/m(3) radon for 24 h, or immediately after intraperitoneal injection of ascorbic acid (100, 300, or 500 mg/kg bodyweight) or α-tocopherol (100, 300, or 500 mg/kg bodyweight). We estimated the inhibitory effects on CCl(4)-induced hepatopathy based on hepatic function-associated parameters, oxidative damage-associated parameters and histological changes. The results revealed that the therapeutic effects of radon inhalation were almost equivalent to treatment with ascorbic acid at a dose of 500 mg/kg or α-tocopherol at a dose of 300 mg/kg. The activities of superoxide dismutase, catalase, and glutathione peroxidase in the liver were significantly higher in mice exposed to radon than in mice treated with CCl(4) alone. These findings suggest that radon inhalation has an anti-oxidative effect against CCl(4)-induced hepatopathy similar to the anti-oxidative effects of ascorbic acid or α-tocopherol due to the induction of anti-oxidative functions.

  10. Comparative study on the inhibitory effects of α-tocopherol and radon on carbon tetrachloride-induced renal damage.

    PubMed

    Kataoka, Takahiro; Yamato, Keiko; Nishiyama, Yuichi; Morii, Yuji; Etani, Reo; Takata, Yuji; Hanamoto, Katsumi; Kawabe, Atsuishi; Sakoda, Akihiro; Ishimori, Yuu; Taguchi, Takehito; Yamaoka, Kiyonori

    2012-01-01

    Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone's attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl4)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl4 after inhaling approximately 1000 or 2000 Bq/m3 radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m3 has the inhibitory effects similar to α-tocopherol treatment at a dose of 300-500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl4 alone. These findings suggest that radon inhalation has an antioxidative effect against CCl4-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions.

  11. Elevated expression of transforming growth factor β3 in carbon tetrachloride-treated rat liver and involvement of retinoid signaling.

    PubMed

    Mezaki, Yoshihiro; Morii, Mayako; Yoshikawa, Kiwamu; Yamaguchi, Noriko; Satoyoshi, Kiyofumi; Miura, Mitsutaka; Imai, Katsuyuki; Hebiguchi, Tatsuzo; Habuchi, Tomonori; Senoo, Haruki

    2012-01-01

    Transforming growth factor (TGF) β is a pro-fibrotic cytokine. While three isoforms (TGF-β1, 2 and 3) are known, the functional differences between them are obscure. To investigate the roles of TGF-β isoforms during liver fibrogenesis, male Wistar rats were administrated carbon tetrachloride (CCl4) subcutaneously twice a week for two months. Livers were excised and sectioned for histochemical examinations. These livers were also used to quantitate the expression of genes associated with fibrogenesis, including TGF-β isoforms, as well as those associated with retinoid metabolism. Expression levels of Tgfb1 and Tgfb3 were up-regulated in CCl4-treated rat livers while that of Tgfb2 was not changed. The mRNAs for lecithin-retinol acyltransferase (Lrat) and retinoic acid hydroxylase, Cyp26a1, were also elevated. By immunohistochemical staining, TGF-β3 protein was found to be localized mainly in liver parenchymal cells (hepatocytes). These results indicate that retinoid mobilization likely takes place within the rat's liver following CCl4 treatment, and suggest the possibility that the expression of Tgfb mRNA is regulated by retinoic acid receptors. Reporter analyses of a region of the Tgfb3 gene were performed using the rat liver parenchymal cell line, RLC-16, and a positively responsive region was identified within its intron.

  12. Protective Effect of the Total Saponins from Rosa laevigata Michx Fruit against Carbon Tetrachloride-Induced Liver Fibrosis in Rats

    PubMed Central

    Dong, Deshi; Yin, Lianhong; Qi, Yan; Xu, Lina; Peng, Jinyong

    2015-01-01

    In this study, the protective effect of the total saponins from Rosa laevigata Michx (RLTS) against liver fibrosis induced by carbon tetrachloride (CCl4) in rats was evaluated. The results showed that RLTS significantly rehabilitated the levels of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, glutathione, glutathione peroxidase, catalase, superoxide dismutase, hydroxyproline, α-smooth muscle actin, collagen I, collagen III and fibronectin, which were confirmed using H&E, Sirius Red and Masson histopathological assays. Further research indicated that RLTS markedly reduced cytochrome P450 2E1 activity, attenuated oxidative stress, and suppressed inflammation. In addition, RLTS facilitated matrix degradation through down-regulation of matrix metalloproteinase2, matrix metalloproteinase 9 and metalloproteinases1, and exerted the anti-fibrotic effects through affecting transforming growth factor β/Smad, focal adhesion kinase/phosphatidylinositol-3-kinase/amino kinase terminal/70-kDa ribosomal S6 Kinase (FAK-PI3K-Akt-p70S6K) and mitogen-activated protein kinase (MAPK) signaling pathways. Taken together, our data indicate that RLTS can be applied as one effective candidate for the treatment of liver fibrosis in the future. PMID:26083117

  13. Antioxidant Activity of Extract and Its Major Constituents from Okra Seed on Rat Hepatocytes Injured by Carbon Tetrachloride

    PubMed Central

    Hu, Lianmei; Yu, Wenlan; Li, Ying; Tang, Zhaoxin

    2014-01-01

    The antioxidant activities and protective effects of total phenolic extracts (TPE) and their major components from okra seeds on oxidative stress induced by carbon tetrachloride (CCl4) in rat hepatocyte cell line were investigated. The major phenolic compounds were identified as quercetin 3-O-glucosyl (1 → 6) glucoside (QDG) and quercetin 3-O-glucoside (QG). TPE, QG, and QDG from okra seeds exhibited excellent reducing power and free radical scavenging capabilities including α, α-diphenyl-β-picrylhydrazyl (DPPH), superoxide anions, and hydroxyl radical. Overall, DPPH radical scavenging activity and reducing power of QG and QDG were higher than those of TPE while superoxide and hydroxyl radical scavenging activities of QG and TPE were higher than those of QDG. Furthermore, TPE, QG, and QDG pretreatments significantly alleviated the cytotoxicity of CCl4 on rat hepatocytes, with attenuated lipid peroxidation, increased SOD and CAT activities, and decreased GPT and GOT activities. The protective effects of TPE and QG on rat hepatocytes were stronger than those of QDG. However, the cytotoxicity of CCl4 on rat hepatocytes was not affected by TPE, QG, and QDG posttreatments. It was suggested that the protective effects of TPE, QG, and QDG on rat hepatocyte against oxidative stress were related to the direct antioxidant capabilities and the induced antioxidant enzymes activities. PMID:24719856

  14. Probing the interaction of amorphous solid water on a hydrophobic surface: dewetting and crystallization kinetics of ASW on carbon tetrachloride.

    PubMed

    May, R Alan; Smith, R Scott; Kay, Bruce D

    2011-11-28

    Desorption of carbon tetrachloride from beneath an amorphous solid water (ASW) overlayer is explored utilizing a combination of temperature programmed desorption and infrared spectroscopy. Otherwise inaccessible information about the dewetting and crystallization of ASW is revealed by monitoring desorption of the CCl(4) underlayer. The desorption maximum of CCl(4) on graphene occurs at ~140 K. When ASW wets the CCl(4) no desorption below 140 K is observed. However, the mobility of the water molecules increases with ASW deposition temperature, leading to a thermodynamically driven dewetting of water from the hydrophobic CCl(4) surface. This dewetting exposes some CCl(4) to the ambient environment, allowing unhindered desorption of CCl(4) below 140 K. When ASW completely covers the underlayer, desorption of CCl(4) is delayed until crystallization induced cracking of the ASW overlayer opens an escape path to the surface. The subsequent rapid episodic release of CCl(4) is termed a "molecular volcano". Reflection absorption infrared spectroscopy (RAIRS) measurements indicate that the onset and duration of the molecular volcano is directly controlled by the ASW crystallization kinetics. PMID:21881656

  15. High-fat diet plus carbon tetrachloride-induced liver fibrosis is alleviated by betaine treatment in rats.

    PubMed

    Bingül, İlknur; Aydın, A Fatih; Başaran-Küçükgergin, Canan; Doğan-Ekici, Işın; Çoban, Jale; Doğru-Abbasoğlu, Semra; Uysal, Müjdat

    2016-10-01

    Steatosis, the first lesion in non-alcoholic fatty liver disease (NAFLD), may progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Steatosis predisposes the liver to oxidative stress, inflammation, and cytokines. Betaine (BET) has antioxidant, antiinflammatory and hepatoprotective effects. However, the effects of BET on liver fibrosis development are unknown. Rats were treated with high-fat diet (60% of total calories from fat) for 14weeks. Carbon tetrachloride (0.2mL/kg; two times per week; i.p.) was administered to rats in the last 6weeks with/without commercial food containing BET (2%; w/w). Serum liver function tests and tumor necrosis factor-α, insulin resistance, hepatic triglyceride (TG) and hydroxyproline (HYP) levels and oxidative stress parameters were determined along with histopathologic observations. Alpha-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions and mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were evaluated. BET decreased TG and HYP levels, prooxidant status and fibrotic changes in the liver. α-SMA, COL1A1 and TGF-β1 protein expressions, MMP-2, TIMP-1, and TIMP-2 mRNA expressions diminished due to BET treatment. BET has an antifibrotic effect and this effect may be related to its antioxidant and antiinflammatory actions together with suppression on HSC activation.

  16. Antioxidant activity of extract and its major constituents from okra seed on rat hepatocytes injured by carbon tetrachloride.

    PubMed

    Hu, Lianmei; Yu, Wenlan; Li, Ying; Prasad, Nagendra; Tang, Zhaoxin

    2014-01-01

    The antioxidant activities and protective effects of total phenolic extracts (TPE) and their major components from okra seeds on oxidative stress induced by carbon tetrachloride (CCl4) in rat hepatocyte cell line were investigated. The major phenolic compounds were identified as quercetin 3-O-glucosyl (1 → 6) glucoside (QDG) and quercetin 3-O-glucoside (QG). TPE, QG, and QDG from okra seeds exhibited excellent reducing power and free radical scavenging capabilities including α, α-diphenyl-β-picrylhydrazyl (DPPH), superoxide anions, and hydroxyl radical. Overall, DPPH radical scavenging activity and reducing power of QG and QDG were higher than those of TPE while superoxide and hydroxyl radical scavenging activities of QG and TPE were higher than those of QDG. Furthermore, TPE, QG, and QDG pretreatments significantly alleviated the cytotoxicity of CCl4 on rat hepatocytes, with attenuated lipid peroxidation, increased SOD and CAT activities, and decreased GPT and GOT activities. The protective effects of TPE and QG on rat hepatocytes were stronger than those of QDG. However, the cytotoxicity of CCl4 on rat hepatocytes was not affected by TPE, QG, and QDG posttreatments. It was suggested that the protective effects of TPE, QG, and QDG on rat hepatocyte against oxidative stress were related to the direct antioxidant capabilities and the induced antioxidant enzymes activities.

  17. Folic acid and melatonin ameliorate carbon tetrachloride-induced hepatic injury, oxidative stress and inflammation in rats

    PubMed Central

    2013-01-01

    This study investigated the protective effects of melatonin and folic acid against carbon tetrachloride (CCl4)-induced hepatic injury in rats. Oxidative stress, liver function, liver histopathology and serum lipid levels were evaluated. The levels of protein kinase B (Akt1), interferon gamma (IFN-γ), programmed cell death-receptor (Fas) and Tumor necrosis factor-alpha (TNF-α) mRNA expression were analyzed. CCl4 significantly elevated the levels of lipid peroxidation (MDA), cholesterol, LDL, triglycerides, bilirubin and urea. In addition, CCl4 was found to significantly suppress the activity of both catalase and glutathione (GSH) and decrease the levels of serum total protein and HDL-cholesterol. All of these parameters were restored to their normal levels by treatment with melatonin, folic acid or their combination. An improvement of the general hepatic architecture was observed in rats that were treated with the combination of melatonin and folic acid along with CCl4. Furthermore, the CCl4-induced upregulation of TNF-α and Fas mRNA expression was significantly restored by the three treatments. Melatonin, folic acid or their combination also restored the baseline levels of IFN-γ and Akt1 mRNA expression. The combination of melatonin and folic acid exhibited ability to reduce the markers of liver injury induced by CCl4 and restore the oxidative stability, the level of inflammatory cytokines, the lipid profile and the cell survival Akt1 signals. PMID:23374533

  18. Hepatoprotective and antioxidant effects of Hibiscus sabdariffa extract against carbon tetrachloride-induced hepatocyte damage in Cyprinus carpio.

    PubMed

    Yin, Guojun; Cao, Liping; Xu, Pao; Jeney, Galina; Nakao, Miki

    2011-01-01

    The present study aims to evaluate the hepatoprotective and antioxidant effects of Hibiscus sabdariffa extract on the carbon tetrachloride (CCl(4))-induced hepatocyte damage in fish and provide evidence as to whether it can be potentially used as a medicine for liver diseases in aquaculture. H. sabdariffa extract (100, 200, and 400 μg/mL) was added to the carp primary hepatocyte culture before (pre-treatment), after (post-treatment), and both before and after (pre- and post-treatment) the incubation of the hepatocytes with CCl(4). CCl(4) at 8 mM in the culture medium produced significantly elevated levels of lactate dehydrogenase (LDH), glutamate oxalate transaminase (GOT), glutamate pyruvate transaminase (GPT), and malondialdehyde (MDA) and significantly reduced levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Pre-treatment and pre- and post-treatment of the hepatocytes with H. sabdariffa extract significantly reduced the elevated levels of LDH, GOT, GPT, and MDA and increased the reduced activities of SOD and GSH-Px in a dose-dependent manner; post-treatment did not show any protective effect. The results suggest that H. sabdariffa extract can be potentially used for preventing rather than curing liver diseases in fish. PMID:21082285

  19. Soil- and surfactant-enhanced reductive dechlorination of carbon tetrachloride in the presence of Shewanella putrefaciens 200

    NASA Astrophysics Data System (ADS)

    Backhus, Debera A.; Picardal, Flynn W.; Johnson, Scott; Knowles, Tracy; Collins, Richard; Radue, Anna; Kim, Sanggoo

    1997-11-01

    Sorption of organic contaminants to soils has been shown to limit bioavailability and biodegradation in some systems. Use of surfactants has been proposed to reverse this effect. In this study, the effects of a high organic carbon content soil and a nonionic surfactant (Triton X-100) on the reductive dechlorination of carbon tetrachloride (CCl 4) were examined in anaerobic systems containing Shewanella putrefaciens. Although more than 70% of the added CCl 4 was sorbed to the soil phase in these systems, the reductive dechlorination of CCl 4 was not diminished. Rather, rates of CCl 4 dechlorination in systems containing soil were enhanced relative to systems containing non-sorptive sand slurries. This enhancement was also observed in sterile soil slurries to which a chemical reductant, dithiothreitol was added. It appears that the organic soil used in these experiments contains some catalytic factor capable of transforming CCl 4 in the presence of an appropriate chemical or microbial reductant. The addition of Triton X-100 to sand and soil slurries containing S. putrefaciens resulted in increased CCl 4 degradation in both systems. The effect of Triton could not be explained by: (i) surfactant induced changes in the distribution of CCl 4, (i.e. decreased sorption) or the rate of CCl 4 desorption; (ii) a direct reaction between Triton and CCl 4; or (iii) increased cell numbers resulting from use of the surfactant as a substrate. Rather, it appears that Triton X-100 addition resulted in lysis of bacterial cells, a release of biochemical reductant, and enhanced reductive transformation of CCl 4. These results provide insights to guide the development of more effective direct or indirect bioremediation strategies.

  20. Dechlorination of carbon tetrachloride by iron metal: Effect of reactant concentrations

    SciTech Connect

    Scherer, M.M.; Tratnyek, P.G.

    1995-12-01

    Optimal application of zero-valent iron (Fe{sup 0}) in contaminant remediation requires an understanding of the mechanism by which the process occurs. An important first step towards developing such an understanding is determining the dependence of reaction rate on the concentration of each reactant. Previous efforts by Matheson and Tratnyek (1994) found that the first-order rate constant for reduction of CCl{sub 4} by Fe{sup 0} increased linearly with iron surface area. However, heterogeneous systems often exhibit more complex behavior, suggesting that the simple linear relationships previously reported may not fully reflect all of the potentially contributing processes. To investigate this possibility, further study of the effect of initial CCl{sub 4} concentration and iron surface area has been undertaken. Our findings suggest that site availability arguments can be applied to the effect of CCl{sub 4} concentration but that the effect of Fe{sup 0} surface area is more complex.

  1. Effect of co-administration of Angelicae gigantis radix and Lithospermi radix on rat hepatic injury induced by carbon tetrachloride

    PubMed Central

    Lim, Chi-Yeon; Kim, Bu-Yeo; Lim, Se-Hyun; Cho, Su-In

    2015-01-01

    Background: Co-administration of Angelicae gigantis radix (AGR) and Lithospermi radix (LR) has been commonly applied to patients to treat cardiac and hepatic disorders. Individual bioactivities of these herbal medicines have been widely investigated, but the hepatoprotective effects of co-treatment of AGR and LR have yet to be clarified. Objective: The present study investigated the protective effects of extracts of AGR and LR on carbon tetrachloride (CCl4) induced hepatic injury. Materials and Methods: In this study, we measured the hepatoprotective activity of individual and co-treatment of the two herbal medicines on hepatic injury induced by CCl4 by measuring different biochemical parameters such as serum aspartate aminotransaminase (AST) and serum alanine aminotransaminase (ALT). Microarray technology also used to compare ontological difference with individual and co-treatment of these two. Results: Combined treatment with AGR and LR (AGR + LR) decreased AST and ALT level in serum which demonstrate hepatoprotective effect of the therapy. When the effect of AGR and LR according to treatment conditions was measured, co-treatment showed the most prominent effect on hepatic injury by CCl4 rather than individual treatment condition. We further defined gene set that could be the molecular target of herbal effect on hepatic injury by CCl4 using bioinformatical analysis of interaction network. Highly recovered genes by treating AGR + LR play significant roles in response to hepatic injury induced by CCl4. Conclusion: Combined treatment with AGR and LR showed synergistic protective effects on the CCl4-induced rat hepatic tissue injury. PMID:25829781

  2. Treatment with L-valine ameliorates liver fibrosis and restores thrombopoiesis in rats exposed to carbon tetrachloride.

    PubMed

    Nakanishi, Chikashi; Doi, Hideyuki; Katsura, Kazunori; Satomi, Susumu

    2010-06-01

    It has been reported that treatment with branched chain amino acids (BCAAs) increases the survival rates in cirrhotic patients. In this study, we investigated the effect of L-valine, one of BCAAs, on liver fibrosis in rat. To induce liver fibrosis, male Wistar rats were injected carbon tetrachloride (CCl(4)) intraperitoneally (2.0 mL/kg) twice a week for 12 weeks. The rats (seven to fifteen rats for each group) were then administered 1.688 g/kg/day of L-valine intravenously for 7 days or 10% amino acid preparation that provided the same amount of nitrogen. Seven days after the last administration, blood platelet counts and bone marrow megakaryocyte counts were significantly higher in the valine group than in the control group (131.2 +/- 38.3 vs. 106.3 +/- 14.5 x 10(4)/microL, p = 0.04; 18.0 +/- 2.1 vs. 13.5 +/- 2.2 per field, p < 0.01, respectively). Importantly, the mRNA level of thrombopoietin, a key regulator of thrombopoiesis, was significantly higher in the liver of the valine group than the control group. Furthermore, hepatic fibrosis was significantly reduced in the valine group, and the mRNA levels of factors associated with liver fibrosis such as procollagen alpha1(III), transforming growth factor-beta1 and connective tissue growth factor were significantly lower in the liver of the valine group 10 days after the last administration. These results indicate that L-valine treatment ameliorates liver fibrosis and restores thrombopoiesis in rats exposed to CCl(4). Therefore, L-valine supplementation may be helpful for patients with liver cirrhosis.

  3. Hepatoprotective activity of the neem-based constituent azadirachtin-A in carbon tetrachloride intoxicated Wistar rats.

    PubMed

    Baligar, N S; Aladakatti, R H; Ahmed, Mukhtar; Hiremath, M B

    2014-04-01

    The aim of this study was to investigate the hepatoprotective role of azadirachtin-A in carbon tetrachloride (CCl4) induced hepatotoxicity in rats. The group allotment for the animals used in the hepatoprotective study included a vehicle treatment group, CCl4 (1 mL · (kg body mass)(-1)) treatment group, silymarin (100 μg · (kg body mass)(-1) · day(-1)) + CCl4 treatment group, and groups treated with different doses of azadirachtin-A (100 or 200 μg · (kg body mass)(-1) · day(-1)) + CCl4. On the 9th day, blood was obtained for measuring the biochemical parameters, and liver tissue was obtained for pathological examination. The acute toxicity test with azadirachtin-A (500, 1000, or 2000 μg · (kg body mass)(-1)) indicated no mortality after 14 days of treatment; further, there was no change in behavior, food consumption, or organ mass. However with the higher dose, some hematological parameters showed changes. Hepatoprotective studies revealed that the CCl4 treatment group exhibited a decrease in total protein and albumin levels, whereas a significant increase in BUN, AST, ALT, and ALP levels were noticed compared with the vehicle-treated control, indicating that there was liver damage caused by CCl4. Histology and ultrastructure study confirmed that pretreatment with azadirachtin-A dose-dependently reduced hepatocellular necrosis and, therefore, protected the liver against toxicity caused by CCl4. The results from this study indicate that pretreatment with azadirachtin-A at the higher dose levels, moderately restores the rat liver to normal. This study confirms that azadirachtin-A possesses greater hepatoprotective action; however, the effective concentration needs to be determined. PMID:24708208

  4. The protective effect of silymarin on the carbon tetrachloride (CCl4)-induced liver injury in common carp (Cyprinus carpio).

    PubMed

    Jia, Rui; Cao, Liping; Du, Jinliang; Xu, Pao; Jeney, Galina; Yin, Guojun

    2013-03-01

    Silymarin, a mixture of bioactive flavonolignans from the milk thistle (Silybum marianum), is traditionally used in herbal medicine to defend against various hepatotoxic agents. The aim of the present study was to evaluate the protective effect of silymarin against carbon tetrachloride (CCl4)-induced liver injury in fish. Common carp, with an average initial weight of 17.0 ± 1.1 g, were fed diet containing four doses of silymarin (0, 0.1, 0.5, and 1 g/kg diet) for 60 d. Fish were then given an intraperitoneal injection of CCl4 (30% in arachis oil) at a dose of 0.5 ml/kg body weight. At 72 h after CCl4 injection, blood and liver samples were collected for the analyses of serum biochemical parameters, liver index, peroxidation product, glutathione, and antioxidant enzyme activities. The results showed that administration of silymarin at 0.5 and 1 g/kg diet for 60 d prior to CCl4 intoxication significantly reduced the elevated activities of glutamate pyruvate transaminase, glutamate oxalate transaminase, lactate dehydrogenase (LDH), and increased the reduced levels of total protein and albumin in the serum. The reduced levels of liver index, superoxide dismutase, glutathione peroxidase, catalase, glutathione, and total antioxidant capacity were markedly increased, and malondialdehyde formation was significantly restrained in the liver. However, these parameters, except LDH, were not significantly changed in fish fed with silymarin at 0.1 g/kg diet. Based on the results, it can be concluded that silymarin has protective effect against CCl4-induced hepatotoxicity in fish. It is suggested that silymarin may be used as a hepatoprotective agent to prevent liver diseases in fish.

  5. Hepatoprotective activity of aerial parts of Otostegia persica against carbon tetrachloride-induced liver damage in rats

    PubMed Central

    Akbartabar Toori, Mehdi; Joodi, Behzad; Sadeghi, Heibatollah; Sadeghi, Hossein; Jafari, Mehrzad; Talebianpoor, Mohammad Sharif; Mehraban, Foad; Mostafazadeh, Mostafa; Ghavamizadeh, Mehdi

    2015-01-01

    Objective: To evaluate the hepatoprotective properties of Otostegia persica (O. persica) ethanol extract on carbon tetrachloride-induced liver damage in rats. Materials and Methods: Fifty adult male Wistar rats were randomly divided into five groups. Group I served as normal control and was given only olive oil intraperitoneally (i.p.). Group II, III, IV, and V were administered CCl4 mixed with olive oil 1:1 (1 ml/kg) i.p., twice a week for 8 weeks. Group II was maintained as CCl4-intoxicated control (hepatotoxic group). Group III, IV, and V received O. persica extract at a dose of 40, 80, and 120 mg/kg for 8 weeks every 48 h orally, respectively. Biochemical parameters including aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin (TB), albumin (ALB), total protein (TP), and lipid peroxidation marker (Malonaldialdehyde, (MDA) were determined in serum. After 8 weeks, animals were sacrificed, livers dissected out, and evaluated for histomorphological changes. Results: The administration of CCl4 increased AST, ALT, ALP, TB, and MDA in serum but it decreased TP , and ALB compared with normal control. Treatment with O. persica extract at three doses resulted in decreased enzyme markers, bilirubin levels, and lipid peroxidation marker (MDA) and increased TP and ALB compared with CCl4 group. The results of pathological study also support the hepatoprotective effects which were observed at doses of 80 and 120 mg/kg. Conclusion: The results of the present study indicate that ethanol extract of O. persica may have hepatoprotective effect which is probably due to its antioxidant property. PMID:26101757

  6. New therapeutic aspect for carvedilol: Antifibrotic effects of carvedilol in chronic carbon tetrachloride-induced liver damage

    SciTech Connect

    Hamdy, Nadia; El-Demerdash, Ebtehal

    2012-06-15

    Portal hypertension is a common complication of chronic liver diseases associated with liver fibrosis and cirrhosis. At present, beta-blockers such as carvedilol remain the medical treatment of choice for protection against variceal bleeding and other complications. Since carvedilol has powerful antioxidant properties we assessed the potential antifibrotic effects of carvedilol and the underlying mechanisms that may add further benefits for its clinical usefulness using a chronic model of carbon tetrachloride (CCl4)-induced hepatotoxicity. Two weeks after CCl4 induction of chronic hepatotoxicity, rats were co-treated with carvedilol (10 mg/kg, orally) daily for 6 weeks. It was found that treatment of animals with carvedilol significantly counteracted the changes in liver function and histopathological lesions induced by CCl4. Also, carvedilol significantly counteracted lipid peroxidation, GSH depletion, and reduction in antioxidant enzyme activities; glutathione-S-transferase and catalase that was induced by CCl4. In addition, carvedilol ameliorated the inflammation induced by CCl4 as indicated by reducing the serum level of acute phase protein marker; alpha-2-macroglobulin and the liver expression of nuclear factor-kappa B (NF-κB). Finally, carvedilol significantly reduced liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cell (HSC) activation marker; alpha smooth muscle actin. In conclusion, the present study provides evidences for the promising antifibrotic effects of carvedilol that can be explained by amelioration of oxidative stress through mainly, replenishment of GSH, restoration of antioxidant enzyme activities and reduction of lipid peroxides as well as amelioration of inflammation and fibrosis by decreasing collagen accumulation, acute phase protein level, NF-κB expression and finally HSC activation. -- Highlights: ► Carvedilol is a beta blocker with antioxidant and antifibrotic

  7. Carbon Tetrachloride Emissions from the US during 2008 - 2012 Derived from Atmospheric Data Using Bayesian and Geostatistical Inversions

    NASA Astrophysics Data System (ADS)

    Hu, L.; Montzka, S. A.; Miller, B.; Andrews, A. E.; Miller, J. B.; Lehman, S.; Sweeney, C.; Miller, S. M.; Thoning, K. W.; Siso, C.; Atlas, E. L.; Blake, D. R.; De Gouw, J. A.; Gilman, J.; Dutton, G. S.; Elkins, J. W.; Hall, B. D.; Chen, H.; Fischer, M. L.; Mountain, M. E.; Nehrkorn, T.; Biraud, S.; Tans, P. P.

    2015-12-01

    Global atmospheric observations suggest substantial ongoing emissions of carbon tetrachloride (CCl4) despite a 100% phase-out of production for dispersive uses since 1996 in developed countries and 2010 in other countries. Little progress has been made in understanding the causes of these ongoing emissions or identifying their contributing sources. In this study, we employed multiple inverse modeling techniques (i.e. Bayesian and geostatistical inversions) to assimilate CCl4 mole fractions observed from the National Oceanic and Atmospheric Administration (NOAA) flask-air sampling network over the US, and quantify its national and regional emissions during 2008 - 2012. Average national total emissions of CCl4 between 2008 and 2012 determined from these observations and an ensemble of inversions range between 2.1 and 6.1 Gg yr-1. This emission is substantially larger than the mean of 0.06 Gg/yr reported to the US EPA Toxics Release Inventory over these years, suggesting that under-reported emissions or non-reporting sources make up the bulk of CCl4 emissions from the US. But while the inventory does not account for the magnitude of observationally-derived CCl4 emissions, the regional distribution of derived and inventory emissions is similar. Furthermore, when considered relative to the distribution of uncapped landfills or population, the variability in measured mole fractions was most consistent with the distribution of industrial sources (i.e., those from the Toxics Release Inventory). Our results suggest that emissions from the US only account for a small fraction of the global on-going emissions of CCl4 (30 - 80 Gg yr-1 over this period). Finally, to ascertain the importance of the US emissions relative to the unaccounted global emission rate we considered multiple approaches to extrapolate our results to other countries and the globe.

  8. Potential impact of silymarin in combination with chlorogenic acid and/or melatonin in combating cardiomyopathy induced by carbon tetrachloride

    PubMed Central

    Al-Rasheed, Nouf M.; Al-Rasheed, Nawal M.; Faddah, L.M.; Mohamed, Azza M.; Mohammad, Raeesa A.; Al-Amin, Maha

    2013-01-01

    The aim of this study was to investigate the effective role of silymarin either alone or in combination with chlorogenic acid and/or melatonin against the toxic impact of carbon tetrachloride (CCl4) induced cardiac infarction. CCl4 (l.2 ml/kg body weight) was administered as a single dose intraperitoneally. The results revealed that the administration of silymarin alone or in combination with chlorogenic acid (CGA) and/or melatonin for 21 consecutive days, 24 h after CCl4 injection to rats, markedly ameliorated the increases in serum markers of cardiac infarction, including troponin T and creatine kinase-MB (CK-MB), as well as increases in the pro-inflammatory biomarkers, including interleukin-6 (IL-6), interferon-γ (IFN-γ) in serum and tumor necrosis factor-α (TNF-α) and C-reactive protein in cardiac tissue compared to CCl4 intoxicated rats. The used agents also successfully modulated the alteration in vascular endothelial growth factor (VEGF) in serum and the oxidative DNA damage and the increase in the apoptosis marker caspase 3 in cardiac tissue in response to CCl4 toxicity. The present biochemical results are supported by histo-pathological examination. The current results proved that treatment with silymarin in combination with CGA and melatonin was the most effective one in ameliorating the toxicity of CCl4 induced cardiac damage and this may support the use of this combination as an effective drug to treat cardiac damage induced by toxic agents. PMID:24955012

  9. Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses

    PubMed Central

    Hu, Lei; Montzka, Stephen A.; Miller, Ben R.; Andrews, Arlyn E.; Miller, John B.; Lehman, Scott J.; Sweeney, Colm; Miller, Scot M.; Thoning, Kirk; Siso, Carolina; Atlas, Elliot L.; Blake, Donald R.; de Gouw, Joost; Gilman, Jessica B.; Dutton, Geoff; Elkins, James W.; Hall, Bradley; Chen, Huilin; Fischer, Marc L.; Mountain, Marikate E.; Nehrkorn, Thomas; Biraud, Sebastien C.; Moore, Fred L.; Tans, Pieter

    2016-01-01

    National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration’s flask air sampling network. We estimate an annual average US emission of 4.0 (2.0–6.5) Gg CCl4 y−1 during 2008–2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y−1) but only 8% (3–22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008–2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach). PMID:26929368

  10. Hepatoprotective effects of Arctium lappa Linne on liver injuries induced by chronic ethanol consumption and potentiated by carbon tetrachloride.

    PubMed

    Lin, Song-Chow; Lin, Chia-Hsien; Lin, Chun-Ching; Lin, Yun-Ho; Chen, Chin-Fa; Chen, I-Cheng; Wang, Li-Ya

    2002-01-01

    Arctium lappa Linne (burdock) is a perennial herb which is popularly cultivated as a vegetable. In order to evaluate its hepatoprotective effects, a group of rats (n = 10) was fed a liquid ethanol diet (4 g of absolute ethanol/ 80 ml of liquid basal diet) for 28 days and another group (n = 10) received a single intraperitoneal injection of 0.5 ml/kg carbon tetrachloride (CCl(4)) in order to potentiate the liver damage on the 21st day (1 day before the beginning of A. lappa treatment). Control group rats were given a liquid basal diet which did not contain absolute ethanol. When 300 mg/kg A. lappa was administered orally 3 times per day in both the 1-day and 7-day treatment groups, some biochemical and histopathological parameters were significantly altered, both in the ethanol group and the groups receiving ethanol supplemented with CCl(4). A. lappa significantly improved various pathological and biochemical parameters which were worsened by ethanol plus CCl(4)-induced liver damage, such as the ethanol plus CCl(4)-induced decreases in total cytochrome P-450 content and NADPH-cytochrome c reductase activity, increases in serum triglyceride levels and lipid peroxidation (the deleterious peroxidative and toxic malondialdehyde metabolite may be produced in quantity) and elevation of serum transaminase levels. It could even restore the glutathione content and affect the histopathological lesions. These results tended to imply that the hepatotoxicity induced by ethanol and potentiated by CCl(4) could be alleviated with 1 and 7 days of A. lappa treatment. The hepatoprotective mechanism of A. lappa could be attributed, at least in part, to its antioxidative activity, which decreases the oxidative stress of hepatocytes, or to other unknown protective mechanism(s).

  11. Modulation of gamma-irradiation and carbon tetrachloride induced oxidative stress in the brain of female rats by flaxseed oil.

    PubMed

    Ismail, Amel F M; Salem, Asmaa A M; Eassawy, Mamdouh M T

    2016-08-01

    The activity of flaxseed oil (FSO) on gamma-irradiation (7Gy) and/or carbon tetrachloride (CCl4) induced acute neurotoxicity in rats' brain was investigated. The results revealed a significant decrease (p<0.05) in superoxide dismutase (SOD), catalase (CAT), glutathione-peroxidase (GSH-Px) activities, reduced glutathione (GSH) and manganese (Mn) contents. Further, a significant elevation (p<0.05) in malondialdehyde, nitric oxide (NO), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1-beta (IL-1β), Interleukin-6 (IL-6), transforming growth factor-beta-1 (TGF-β1), iron (Fe), calcium (Ca), copper (Cu) and magnesium (Mg) levels were observed. Furthermore, the relative ratio of xanthine oxidase (XO) and inducible nitric-oxide synthase (iNOS) gene expression levels were elevated in the brain tissues of γ-irradiated and CCl4 intoxicated animals. Those effects were augmented due to the effect of CCl4-induced toxicity in γ-irradiated rats. The treatment of FSO displayed significant amendment of the studied parameters in the brain tissues of γ-irradiated and CCl4 intoxicated animals. FSO has a neuroprotective effect against CCl4-induced brain injury in gamma-irradiated rats. This effect is interrelated to the ability of FSO to scavenges the free radicals, enhances the antioxidant enzymes activity, increases GSH contents, down-regulates the inflammatory responses, ameliorates the iron, calcium, copper, magnesium, manganese levels and inhibiting the gene expression level of XO and iNOS in the brain tissues of intoxicated animals. In conclusion, this study demonstrated that the potent antioxidant and anti-inflammatory activities of FSO have the ability to improve the antioxidant status, suppress the inflammatory responses, and regulate the trace elements in the brain tissues of γ-irradiated, CCl4, and their combined effect in intoxicated animals. Consequently, FSO exhibited neuroprotective activity on γ-irradiated, CCl4, and their combined effect induced brain injury in

  12. Phospholipid hydroperoxide accumulation in liver of rats intoxicated with carbon tetrachloride and its inhibition by dietary alpha-tocopherol.

    PubMed

    Miyazawa, T; Suzuki, T; Fujimoto, K; Kaneda, T

    1990-05-01

    The formation and accumulation of phospholipid hydroperoxides, especially of phosphatidylcholine hydroperoxide (PCOOH), a primary peroxidation product of phosphatidylcholine (PC), in livers of carbon tetrachloride-intoxicated rats was investigated. PCOOH in liver and blood plasma was measured by a chemiluminescence-high-performance liquid chromatography procedure originally developed by Miyazawa et al. (Anal. Lett. 20, 915, 1987; Free Radical Biol. Med. 7, 209, 1989). Male Sprague-Dawley rats (120 g body wt., 5 weeks of age) were used in the experiments. The amount of PCOOH in the liver of control rats (CCl4-untreated) was 160 +/- 20 pmol/100 mg protein (mean +/- SD) and the PCOOH/PC molar ratio was 1.1 +/- 0.1 X 10(-5). In CCl4 (0.1 ml/100 g body wt.)-dosed rats, the liver PCOOH was 289 +/- 65 pmol/100 mg protein (PCOOH/PC = 2.4 +/- 0.4 X 10(-5], 764 +/- 271 pmol/100 mg protein (PCOOH/PC = 5.2 +/- 1.7 X 10(-5], and 856 +/- 165 pmol/100 mg protien (PCOOH/PC = 6.0 +/- 0.8 X 10(-5] at 6 h, 24 h, and 1 week after the dose, respectively. Under such conditions, the liver phosphatidylethanolamine hydroperoxide (PEOOH) level was not altered and the concentration was less than 100 pmol/100 mg protein even after the dose. The increments of liver PCOOH were suppressed 56% by the oral supplementation of DL-alpha-tocopherol (5 mg/100 g body wt./day) for a week before CCl4 administration. A relatively larger amount of PEOOH was found after stimulation of PC hydroperoxidation in the liver of rats with a large amount of CCl4 (0.25 ml/100 g body wt.) rather than with the small amount of CCl4 (0.1 ml/100 g body wt.).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Ameliorative effects of tannic acid on carbon tetrachloride-induced liver fibrosis in vivo and in vitro.

    PubMed

    Chu, Xi; Wang, Hua; Jiang, Yan-min; Zhang, Yuan-yuan; Bao, Yi-fan; Zhang, Xuan; Zhang, Jian-ping; Guo, Hui; Yang, Fan; Luan, Yan-chao; Dong, Yong-sheng

    2016-01-01

    We investigated the ameliorative effects and potential mechanisms of tannic acid (TA) in carbon tetrachloride (CCl4)-intoxicated mice and hepatic stellate cells (HSCs). Liver fibrosis was observed in CCl4 (800 ml/kg)-induced mice, and high viability was observed in CCl4 (10 mM)-intoxicated HSCs. Pre-treatment of mice with TA (25 or 50 g/kg/day) significantly ameliorated hepatic morphology and coefficient values and reduced the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), the concentrations of malondialdehyde (MDA) and serum levels of endothelin-1 (ET-1). In addition, TA increased the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and endothelial nitric oxide synthase (eNOS) and the serum level of NO. Moreover, TA reduced the expression of angiotensin II receptor-1 (ATR-1), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), caspase-3, c-fos, c-jun, the ratio of Bax/bcl-2, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TA increased matrix metal proteinase-9 (MMP-9), matrix metalloproteinase-1 (MMP-1). Furthermore, TA (0.01 μM, 0.1 μM or 1 μM) decreased the TIMP-1/MMP-1 ratio and reduced the viability of HSCs. These results indicated that TA exerts significant liver-protective effects in mice with CCl4-induced liver fibrosis. The potential mechanism may rely on the inhibition of collagen accumulation, oxidative stress, inflammation and apoptosis. PMID:26810570

  14. Modulation of gamma-irradiation and carbon tetrachloride induced oxidative stress in the brain of female rats by flaxseed oil.

    PubMed

    Ismail, Amel F M; Salem, Asmaa A M; Eassawy, Mamdouh M T

    2016-08-01

    The activity of flaxseed oil (FSO) on gamma-irradiation (7Gy) and/or carbon tetrachloride (CCl4) induced acute neurotoxicity in rats' brain was investigated. The results revealed a significant decrease (p<0.05) in superoxide dismutase (SOD), catalase (CAT), glutathione-peroxidase (GSH-Px) activities, reduced glutathione (GSH) and manganese (Mn) contents. Further, a significant elevation (p<0.05) in malondialdehyde, nitric oxide (NO), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1-beta (IL-1β), Interleukin-6 (IL-6), transforming growth factor-beta-1 (TGF-β1), iron (Fe), calcium (Ca), copper (Cu) and magnesium (Mg) levels were observed. Furthermore, the relative ratio of xanthine oxidase (XO) and inducible nitric-oxide synthase (iNOS) gene expression levels were elevated in the brain tissues of γ-irradiated and CCl4 intoxicated animals. Those effects were augmented due to the effect of CCl4-induced toxicity in γ-irradiated rats. The treatment of FSO displayed significant amendment of the studied parameters in the brain tissues of γ-irradiated and CCl4 intoxicated animals. FSO has a neuroprotective effect against CCl4-induced brain injury in gamma-irradiated rats. This effect is interrelated to the ability of FSO to scavenges the free radicals, enhances the antioxidant enzymes activity, increases GSH contents, down-regulates the inflammatory responses, ameliorates the iron, calcium, copper, magnesium, manganese levels and inhibiting the gene expression level of XO and iNOS in the brain tissues of intoxicated animals. In conclusion, this study demonstrated that the potent antioxidant and anti-inflammatory activities of FSO have the ability to improve the antioxidant status, suppress the inflammatory responses, and regulate the trace elements in the brain tissues of γ-irradiated, CCl4, and their combined effect in intoxicated animals. Consequently, FSO exhibited neuroprotective activity on γ-irradiated, CCl4, and their combined effect induced brain injury in

  15. Theoretical and experimental studies of the dechlorination mechanism of carbon tetrachloride on a vivianite ferrous phosphate surface.

    PubMed

    Jeon, Keonghee; Lee, Nara; Bae, Sungjun; Goddard, William A; Kim, Hyungjun; Lee, Woojin

    2015-06-01

    Chlorinated organics are the principal and most frequently found contaminants in soil and groundwater, generating significant environmental problems. Over the past several decades, Fe-containing minerals naturally occurring in aquatic and terrestrial environments have been used as natural electron donors, which can effectively dechlorinate a variety of chlorinated organics. However, a full understanding of the reaction mechanism of the dechlorination pathway cannot be obtained by experimental investigations alone, due to the immeasurability of chemical species formed over a short reaction time. In this report, we describe experiments and density functional theory (DFT) calculations carried out to investigate the complex reduction pathway of carbon tetrachloride (CT) on a vivianite (Fe(II)3(PO4)2·8H2O) surface. Our results indicate that chloroform (HCCl3) and formate are the primary transformation products. The experimental results reveal that the reduction kinetics of CCl4 can be dramatically accelerated as the pH is increased from 3 to 11. On the basis of the DFT calculations, we found that HCCl3 can be formed by (•)CCl3 and :CCl3(-)* on a deprotonated vivianite surface (an adsorbate on vivianite is denoted using an asterisk). In addition, :CCl3(-)* can be nonreductively dechlorinated to form :CCl2* followed by sequential nucleophilic attack by OH(-)*, resulting in the formation of :CCl(OH)* and :C(OH)2*, which are responsible for production of CO and formate, respectively. The results obtained from this study can facilitate the modeling of systems of other halogenated species and minerals, which will provide fundamental insight into their corresponding reaction mechanisms. PMID:25924055

  16. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene.

    PubMed

    Jha, Kshitij C; Liu, Zhuonan; Vijwani, Hema; Nadagouda, Mallikarjuna; Mukhopadhyay, Sharmila M; Tsige, Mesfin

    2016-01-01

    Adsorption of chlorinated organic contaminants (COCs) on carbon nanotubes (CNTs) has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE), the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants. PMID:27455218

  17. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene.

    PubMed

    Jha, Kshitij C; Liu, Zhuonan; Vijwani, Hema; Nadagouda, Mallikarjuna; Mukhopadhyay, Sharmila M; Tsige, Mesfin

    2016-01-01

    Adsorption of chlorinated organic contaminants (COCs) on carbon nanotubes (CNTs) has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE), the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants.

  18. Subchronic inhalation of carbon tetrachloride alters the tissue retention of acutely inhaled plutonium-239 nitrate in F344 rats and syrian golden hamsters

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.

    1995-12-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is likely that nuclear plant workers have been exposed to both CCl{sub 4} and plutonium compounds. Future exposures may occur during {open_quotes}cleanup{close_quotes} operations at weapons productions sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. Inhalation of 20 and 100 ppm CCl{sub 4} by hamsters reduces uptake of {sup 239}Pu solubilized from lung, shunting the {sup 239}Pu to the skeleton.

  19. Determination of Carbon Dioxide in Refined Titanium Tetrachloride by Infrared Spectroscopy.

    PubMed

    Song, Guang-lin; Luo, Yun-jun; Li, Jin-qing; Tan, Hong

    2015-03-01

    Refined TiCl4 is the key procedure in producing titanium sponge. Besides, the content of carbon and oxygen (C and O) impurities in titanium sponge and that of C and O impurities in refined TiCl4 presents the 4-times enrichment relationship. Therefore, the content control of the C and O impurities in refined TiCl4 becomes the key part for the quality control of titanium material. In order to control the oxygen and carbon, there is the need to analyze the source of C and O impurities so that strict control can be conducted over the impurities of refined TiCl4. Determination of CO2 in refined TiCl4 was significant for analysis of its impurities. CO2 could be determined by infrared spectroscopy due to its infrared characteristic spectrum line. However, normal infrared absorption cell was not fit for the sample analysis, because TiCl4 easily reacted with moisture in the air and immediately was hydrolyzed to form highly corrosive hydrochloric acid smoke. According to Lambert-Beer Law, which means the concentration (c(ξ)) and absorbance(A) - length (L) curve's slope have direct ratio. The infrared absorption cell with the window film of ZnSe (φ10 mm x 1 mm, wavenumers: 7 800 -440 cm(-1)) and the glass cell (optical path: 42, 22, 12, 7 and 4 mm) was assembled and utilized in determination of the CO2 in refined TiCl4 by standard addition method. The detection limit of CO2 was 0.92 mg x kg(-1), the regression equation was Y = 0.031 1X, R = 0.997 2; With standard addition method, the regression equation of CO2 was Y = 0.131 7X, R = 0.998 6, it's good in linearity relation, the CO2 content in refined TiCl4 is determined to be 1.53 mg x kg(-1) and SD up to 0.04 x mg x kg(-1). RSD of the method precision is between 0.53%-1.27%, while recovery rate is between 89.2%-96.8%. This infrared absorption device was safe, simple and convenient, easily removable and washable, and re-useable. The method could conduct the quantitative analysis over the CO2 content in refined TiCl4 through

  20. Destruction of chlorobenzene and carbon tetrachloride in a two-stage molten salt oxidation reactor system.

    PubMed

    Yang, Hee-Chul; Cho, Yong-Jun; Eun, Hee-Chul; Kim, Eung-Ho

    2008-08-01

    Molten salt oxidation (MSO) is one of the promising alternative destruction technologies for chlorinated organics, because it is capable of trapping chlorine during organic destruction. This study investigated the characteristics of a two-stage MSO reactor system for the destruction of CCl(4) and C(6)H(5)Cl. Investigated parameters were the MSO reactor temperature (from 1023 K to 1223 K) and the excess oxidizing air feed rate (50% and 100%). The destruction of chlorinated solvents is substantial in the Li(2)CO(3)-Na(2)CO(3) eutectic molten salt, irrespective of the tested condition. However, further oxidation of CO, which is found to be the major destruction product, is not substantial due to the limited temperature and gas residence time in the MSO reactor. Increases in the reactor temperature as well as those in the oxidizing air feed rate consistently lead to decreased emissions of carbon monoxide. No significant influence of the MSO reactor operating condition on the chlorine capturing efficiency was found. Over 99.95% and 99.997% of the chlorine was captured in the hot MSO reactors during the C(6)H(5)Cl and CCl(4) destructions, respectively. This result suggests a relatively low potential of the MSO system in the recombination of chlorinated organics, when compared to a conventional incineration system. PMID:18501405

  1. Destruction of chlorobenzene and carbon tetrachloride in a two-stage molten salt oxidation reactor system.

    PubMed

    Yang, Hee-Chul; Cho, Yong-Jun; Eun, Hee-Chul; Kim, Eung-Ho

    2008-08-01

    Molten salt oxidation (MSO) is one of the promising alternative destruction technologies for chlorinated organics, because it is capable of trapping chlorine during organic destruction. This study investigated the characteristics of a two-stage MSO reactor system for the destruction of CCl(4) and C(6)H(5)Cl. Investigated parameters were the MSO reactor temperature (from 1023 K to 1223 K) and the excess oxidizing air feed rate (50% and 100%). The destruction of chlorinated solvents is substantial in the Li(2)CO(3)-Na(2)CO(3) eutectic molten salt, irrespective of the tested condition. However, further oxidation of CO, which is found to be the major destruction product, is not substantial due to the limited temperature and gas residence time in the MSO reactor. Increases in the reactor temperature as well as those in the oxidizing air feed rate consistently lead to decreased emissions of carbon monoxide. No significant influence of the MSO reactor operating condition on the chlorine capturing efficiency was found. Over 99.95% and 99.997% of the chlorine was captured in the hot MSO reactors during the C(6)H(5)Cl and CCl(4) destructions, respectively. This result suggests a relatively low potential of the MSO system in the recombination of chlorinated organics, when compared to a conventional incineration system.

  2. Dillenia suffruticosa L. Impedes Carbon Tetrachloride-Induced Hepatic Damage by Modulating Oxidative Stress and Inflammatory Markers in Rats.

    PubMed

    Shah, Muhammad Dawood; Gnanaraj, Charles; Khan, Mohammad Shaheen; Iqbal, Mohammad

    2015-01-01

    Dillenia suffruticosa L. (Dilleniaceae) is used in traditional medicine for protection against various diseases. The current study was designed to investigate the bioactive compounds and hepatoprotective potential of methanol leaves extract of D. suffruticosa against carbon tetrachloride (CCl4)-induced hepatic oxidative injury. Sprague Dawley rats were pretreated with methanol extract of D. suffruticosa leaves (200, 300, and 400 mg/kg body weight [bwt]) once daily for 14 days followed by two doses of CCl4 (1.0 mL/kg bwt). After 2 weeks the rats were sacrificed and hepatoprotective analysis was performed. The identified bioactive compounds include phenol (1.39%); benzyl alcohol (2.04%); 2H-pyran-2-one, 4,6-dimethyl (1.19%); phenol, 2,4-bis(1,1-dimethylethyl) (0.83%); dodecanoic acid (0.84%); hexadecanoic acid, methyl ester (2.66%); n-hexadecanoic acid (0.96%); and phytol (2.13%). The administration of D. suffruticosa significantly depleted the elevation of enzymatic levels of alanine transaminase and aspartate transaminase (4% to 59% recovery), reduced the extent of malondialdehyde production (13% to 79% recovery), elevated the level of reduced glutathione (5% to 21% recovery), and increased the activities of antioxidant enzymes (0.43% to 35% recovery). Histopathological analyses by light and electron microscopy revealed that the plant extract protects the liver from the toxic effects of CCl4 and cured lesions such as necrosis and fatty degeneration. It also decreased hepatocyte injuries such as irregular lamellar organization and dilations in endoplasmic reticulum. Immunohistochemical studies indicate the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxyl-2-nonenal (HNE)-modified protein adducts. In addition, the overexpression of the inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and prostaglandin E2 (PGE2) are reduced. Hence, we find D. suffruticosa to be a good source of bioactive compounds with hepatoprotective

  3. Rat liver mitochondrial damage under acute or chronic carbon tetrachloride-induced intoxication: Protection by melatonin and cranberry flavonoids

    SciTech Connect

    Cheshchevik, V.T.; Lapshina, E.A.; Dremza, I.K.; Zabrodskaya, S.V.; Reiter, R.J.; Prokopchik, N.I.; Zavodnik, I.B.

    2012-06-15

    In current societies, the risk of toxic liver damage has markedly increased. The aim of the present work was to carry out further research into the mechanism(s) of liver mitochondrial damage induced by acute (0.8 g/kg body weight, single injection) or chronic (1.6 g/ kg body weight, 30 days, biweekly injections) carbon tetrachloride – induced intoxication and to evaluate the hepatoprotective potential of the antioxidant, melatonin, as well as succinate and cranberry flavonoids in rats. Acute intoxication resulted in considerable impairment of mitochondrial respiratory parameters in the liver. The activity of mitochondrial succinate dehydrogenase (complex II) decreased (by 25%, p < 0.05). Short-term melatonin treatment (10 mg/kg, three times) of rats did not reduce the degree of toxic mitochondrial dysfunction but decreased the enhanced NO production. After 30-day chronic intoxication, no significant change in the respiratory activity of liver mitochondria was observed, despite marked changes in the redox-balance of mitochondria. The activities of the mitochondrial enzymes, succinate dehydrogenase and glutathione peroxidase, as well as that of cytoplasmic catalase in liver cells were inhibited significantly. Mitochondria isolated from the livers of the rats chronically treated with CCl{sub 4} displayed obvious irreversible impairments. Long-term melatonin administration (10 mg/kg, 30 days, daily) to chronically intoxicated rats diminished the toxic effects of CCl{sub 4}, reducing elevated plasma activities of alanine aminotransferase and aspartate aminotransferase and bilirubin concentration, prevented accumulation of membrane lipid peroxidation products in rat liver and resulted in apparent preservation of the mitochondrial ultrastructure. The treatment of the animals by the complex of melatonin (10 mg/kg) plus succinate (50 mg/kg) plus cranberry flavonoids (7 mg/kg) was even more effective in prevention of toxic liver injury and liver mitochondria damage

  4. Colchicine antimitosis abolishes resiliency of postnatally developing rats to chlordecone-amplified carbon tetrachloride hepatotoxicity and lethality.

    PubMed Central

    Dalu, A; Rao, P S; Mehendale, H M

    1998-01-01

    We have previously reported that rats are resilient to the hepatotoxic and lethal combination of chlordecone (CD) and carbon tetrachloride (CCl4) during early postnatal development. The overall findings pointed to stimulated cell division and tissue repair mechanisms as the underlying cause of resistance. The objective of the current study was to investigate if the antimitotic effect of colchicine (CLC) abolishes this resiliency to CD + CCl4 by inhibiting ongoing and stimulated cell division. We used 45-day-old rats in this study because this age group exhibited partial sensitivity to CD + CCl4 in our previous studies. Male Sprague-Dawley rats were treated with a single low intraperitoneal dose of CCl4 (100 microl/kg) or corn oil after exposure to either 10 ppm CD in the diet or a normal diet (ND) for 15 days. CLC (1 mg/kg) was administered 6 or 30 hr after CCl4 to ND or CD rats, respectively. Administration of CLC resulted in increased CCl4-induced mortality from 25% to 85% in rats pretreated with CD, in contrast to 100% survival in ND rats. Liver injury was assessed by plasma alanine transaminase (ALT) and sorbitol dehydrogenase (SDH) elevations as well as by histopathology. Hepatocellular regeneration was assessed by 3H-thymidine (3H-T) incorporation into hepatonuclear DNA and proliferating cell nuclear antigen (PCNA) studies during 0-96 hr after CCl4. Administration of CLC to ND + CCl4 rats resulted in a slight delay in cell division and tissue repair, as indicated by 3H-T incorporation and PCNA, thereby leading to prolonged liver injury as revealed by elevations in plasma ALT, SDH, and histopathological lesions. In contrast, CLC administration to CD + CCl4-treated rats further delayed and diminished cell division by 80%, which led to unrestrained progression of CCl4-induced liver injury, resulting in 85% mortality. These findings underscore the importance of ongoing and toxicant-stimulated cell division and tissue repair mechanisms in hepatotoxicity, and the

  5. Inhibition of soluble epoxide hydrolase attenuates hepatic fibrosis and endoplasmic reticulum stress induced by carbon tetrachloride in mice

    SciTech Connect

    Harris, Todd R.; Bettaieb, Ahmed; Kodani, Sean; Dong, Hua; Myers, Richard; Chiamvimonvat, Nipavan; Haj, Fawaz G.; Hammock, Bruce D.

    2015-07-15

    Liver fibrosis is a pathological condition in which chronic inflammation and changes to the extracellular matrix lead to alterations in hepatic tissue architecture and functional degradation of the liver. Inhibitors of the enzyme soluble epoxide hydrolase (sEH) reduce fibrosis in the heart, pancreas and kidney in several disease models. In this study, we assess the effect of sEH inhibition on the development of fibrosis in a carbon tetrachloride (CCl{sub 4})-induced mouse model by monitoring changes in the inflammatory response, matrix remolding and endoplasmic reticulum stress. The sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) was administered in drinking water. Collagen deposition in the liver was increased five-fold in the CCl{sub 4}-treated group, and this was returned to control levels by TPPU treatment. Hepatic expression of Col1a2 and 3a1 mRNA was increased over fifteen-fold in the CCl{sub 4}-treated group relative to the Control group, and this increase was reduced by 50% by TPPU treatment. Endoplasmic reticulum (ER) stress observed in the livers of CCl{sub 4}-treated animals was attenuated by TPPU treatment. In order to support the hypothesis that TPPU is acting to reduce the hepatic fibrosis and ER stress through its action as a sEH inhibitor we used a second sEH inhibitor, trans-4-(4-[3-(4-trifluoromethoxy-phenyl)-ureido]-cyclohexyloxy)-benzoic acid (t-TUCB), and sEH null mice. Taken together, these data indicate that the sEH may play an important role in the development of hepatic fibrosis induced by CCl{sub 4}, presumably by reducing endogenous fatty acid epoxide chemical mediators acting to reduce ER stress. - Highlights: • We administer an inhibitor of sEH in a CCl4 murine model. • sEH inhibition reduces liver collagen deposition and pro-fibrotic gene expression. • sEH inhibition induces MMP-1a activity.

  6. Involvement of TGF-β1/Smad3 Signaling in Carbon Tetrachloride-Induced Acute Liver Injury in Mice

    PubMed Central

    Niu, Liman; Cui, Xueling; Qi, Yan; Xie, Dongxue; Wu, Qian; Chen, Xinxin; Ge, Jingyan; Liu, Zhonghui

    2016-01-01

    Transforming growth factor-beta1 (TGF-β1) is a major factor in pathogenesis of chronic hepatic injury. Carbon tetrachloride (CCl4) is a liver toxicant, and CCl4-induced liver injury in mouse is a classical animal model of chemical liver injury. However, it is still unclear whether TGF-β1 is involved in the process of CCl4-induced acute chemical liver injury. The present study aimed to evaluate the role of TGF-β1 and its signaling molecule Smad3 in the acute liver injury induce by CCl4. The results showed that CCl4 induced acute liver injury in mice effectively confirmed by H&E staining of liver tissues, and levels of not only liver injury markers serum ALT and AST, but also serum TGF-β1 were elevated significantly in CCl4-treated mice, compared with the control mice treated with olive oil. Our data further revealed that TGF-β1 levels in hepatic tissue homogenate increased significantly, and type II receptor of TGF-β (TβRII) and signaling molecules Smad2, 3, mRNA expressions and Smad3 and phospho-Smad3 protein levels also increased obviously in livers of CCl4-treated mice. To clarify the effect of the elevated TGF-β1/Smad3 signaling on CCl4-induced acute liver injury, Smad3 in mouse liver was overexpressed in vivo by tail vein injection of Smad3-expressing plasmids. Upon CCl4 treatment, Smad3-overexpressing mice showed more severe liver injury identified by H&E staining of liver tissues and higher serum ALT and AST levels. Simultaneously, we found that Smad3-overexpressing mice treated with CCl4 showed more macrophages and neutrophils infiltration in liver and inflammatory cytokines IL-1β and IL-6 levels increment in serum when compared with those in control mice treated with CCl4. Moreover, the results showed that the apoptosis of hepatocytes increased significantly, and apoptosis-associated proteins Bax, cytochrome C and the cleaved caspase 3 expressions were up-regulated in CCl4-treated Smad3-overexpressing mice as well. These results suggested that TGF

  7. Comparison of imatinib, nilotinib and silymarin in the treatment of carbon tetrachloride-induced hepatic oxidative stress, injury and fibrosis

    SciTech Connect

    Shaker, Mohamed E.; Zalata, Khaled R.; Mehal, Wajahat Z.; Shiha, Gamal E.; Ibrahim, Tarek M.

    2011-04-15

    Effective and well-tolerated anti-fibrotic drugs are currently lacking. Therefore, this study was carried out to investigate the potential anti-fibrotic effects of imatinib, nilotinib and silymarin on established hepatic fibrosis in the carbon tetrachloride (CCl{sub 4}) rat model. Male Wistar rats received intraperitoneal injections of CCl{sub 4} twice weekly for 8 weeks, as well as daily intraperitoneal treatments of imatinib (10 and 20 mg/kg), nilotinib (10 and 20 mg/kg) and silymarin (100 mg/kg) during the last 4 weeks of CCl{sub 4}-intoxication. At the end of the study, hepatic damage was evaluated by analysis of liver function tests and hepatic oxidative stress parameters. Hepatic fibrosis was evaluated by histopathology and morphometry, as well as collagen and 4-hydroxyproline contents. Nilotinib (20 mg/kg) was the most effective treatment to counteract CCl{sub 4}-induced hepatic injury as indicated by liver function tests and histopathology. Nilotinib (10 mg/kg), nilotinib (20 mg/kg) and silymarin (100 mg/kg) treatments reduced the mean score of hepatic fibrosis by 31%, 68% and 47%, respectively, and hepatic collagen content by 47%, 49% and 18%, respectively in CCl{sub 4}-treated rats. Hepatic morphometric evaluation and 4-hydroxyproline content revealed that CCl{sub 4}-induced fibrosis was ameliorated significantly by nilotinib (20 mg/kg) and imatinib (20 mg/kg). Unlike nilotinib, imatinib (20 mg/kg) showed some sort of hepatic injury evidenced by elevation of serum aminotransferases and total bilirubin levels, and hepatic total nitrate/nitrite content, as well as characteristic anisonucleosis visualized with the hematoxylin-eosin staining. In conclusion, this study provides the evidence that nilotinib exerts anti-fibrotic activity and suggests that it may be valuable in the treatment of hepatic fibrosis in humans. - Graphical abstract: Display Omitted Research Highlights: > The anti-fibrotic effects of imatinib, nilotinib and silymarin were compared

  8. The antioxidant effect of β-caryophyllene protects rat liver from carbon tetrachloride-induced fibrosis by inhibiting hepatic stellate cell activation.

    PubMed

    Calleja, Miguel Angel; Vieites, Jose María; Montero-Meléndez, Trinidad; Montero-Meterdez, Trinidad; Torres, María Isabel; Faus, María José; Gil, Angel; Suárez, Antonio

    2013-02-14

    Plant-based whole foods provide thousands of bioactive metabolites to the human diet that reduce the risk of developing chronic diseases. β-Caryophyllene (CAR) is a common constituent of the essential oil of numerous plants, vegetables, fruits and medicinal herbs, and has been used as a flavouring agent since the 1930 s. Here, we report the antioxidant activity of CAR, its protective effect on liver fibrosis and its inhibitory capacity on hepatic stellate cell (HSC) activation. CAR was tested for the inhibition of lipid peroxidation and as a free radical scavenger. CAR had higher inhibitory capacity on lipid peroxidation than probucol, α-humulene and α-tocopherol. Also, CAR showed high scavenging activities against hydroxyl radical and superoxide anion. The activity of 5-lipoxygenase, an enzyme that actively participates in fibrogenesis, was significantly inhibited by CAR. Carbon tetrachloride-treated rats received CAR at 2, 20 and 200 mg/kg. CAR significantly improved liver structure, and reduced fibrosis and the expression of Col1a1, Tgfb1 and Timp1 genes. Oxidative stress was used to establish a model of HSC activation with overproduction of extracellular matrix proteins. CAR (1 and 10 μm) increased cell viability and significantly reduced the expression of fibrotic marker genes. CAR, a sesquiterpene present in numerous plants and foods, is as a natural antioxidant that reduces carbon tetrachloride-mediated liver fibrosis and inhibits hepatic cell activation.

  9. A Continuous Flow Column Study of the Anaerobic Transformation of a CAH Mixture of Tetrachloroethene and Carbon Tetrachloride Using Formate as an Electron Donor

    NASA Astrophysics Data System (ADS)

    Semprini, L.; Azizian, M. F.; Kim, Y.

    2011-12-01

    Many groundwater sites are contaminated with mixtures of chlorinated aliphatic hydrocarbons (CAHs) that represent a challenge when biological remediation processes are being considered. This is especially challenging when high concentrations of CAHs are present.Trichloromethane (CF), for example, has been observed to inhibit and potentially exert toxicity on reductive dehalogenation of tetrachloroethene (PCE) and trichloroethene (TCE). Results will be presented from a continuous flow column study where the simultaneous transformation of PCE and carbon tetrachloride (CT) was achieved. The column was packed with a quartz sand and bioaugmented with the Evanite Culture (EV) that is capable of transforming PCE to ethene. The column was fed a synthetic groundwater that was amended with PCE to achieve an influent concentration near its solubility limit (0.10 mM) and formate (1.5 mM) that reacts to produce hydrogen as the ultimate electron donor. The column was operated for over 1600 days prior to the addition of CT. During this period PCE was transformed mainly to vinyl chloride (VC) and ethene (ETH) and minor amounts of cis-dichloroethene (cis-DCE) and TCE. The transformation extent achieved based on the column effluent concentrations ranged from about 50% ETH, 30% VC, and 20 cis-DCE up to 80% ETH and 20% VC. When the column was fed sulfate, it was completely transformed via sulfate reduction. Ferrous iron production from ferric iron reduction was observed early in the study. Acetate was also formed as a result of homoacetogenesis from hydrogen utilization. CT addition (0.015 mM) was started at 1600 days while PCE addition was continued. During the first 25 days of CT addition, CT concentrations gradually increased to 50% of the injection concentration and chloromethane (CM) and CF were observed as transformation products. CT concentrations then decreased with over 98% transformation achieved.CM was removed to below the detection limit and CF concentration decreases to

  10. Iron-carbon composites for the remediation of chlorinated hydrocarbons

    NASA Astrophysics Data System (ADS)

    Sunkara, Bhanu Kiran

    This research is focused on engineering submicron spherical carbon particles as effective carriers/supports for nanoscale zerovalent iron (NZVI) particles to address the in situ remediation of soil and groundwater chlorinated contaminants. Chlorinated hydrocarbons such as trichloroethylene (TCE) and tetrachloroethylene (PCE) form a class of dense non-aqueous phase liquid (DNAPL) toxic contaminants in soil and groundwater. The in situ injection of NZVI particles to reduce DNAPLs is a potentially simple, cost-effective, and environmentally benign technology that has become a preferred method in the remediation of these compounds. However, unsupported NZVI particles exhibit ferromagnetism leading to particle aggregation and loss in mobility through the subsurface. This work demonstrates two approaches to prepare carbon supported NZVI (iron-carbon composites) particles. The objective is to establish these iron-carbon composites as extremely useful materials for the environmental remediation of chlorinated hydrocarbons and suitable materials for the in situ injection technology. This research also demonstrates that it is possible to vary the placement of iron nanoparticles either on the external surface or within the interior of carbon microspheres using a one-step aerosol-based process. The simple process of modifying iron placement has significant potential applications in heterogeneous catalysis as both the iron and carbon are widely used catalysts and catalyst supports. Furthermore, the aerosol-based process is applied to prepare new class of supported catalytic materials such as carbon-supported palladium nanoparticles for ex situ remediation of contaminated water. The iron-carbon composites developed in this research have multiple functionalities (a) they are reactive and function effectively in reductive dehalogenation (b) they are highly adsorptive thereby bringing the chlorinated compound to the proximity of the reactive sites and also serving as adsorption

  11. Amelioration of carbon tetrachloride-induced cirrhosis and portal hypertension in rat using adenoviral gene transfer of Akt

    PubMed Central

    Deng, Gang; Huang, Xiang-Jun; Luo, Hong-Wu; Huang, Fei-Zhou; Liu, Xun-Yang; Wang, Yong-Heng

    2013-01-01

    AIM: To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride (CCl4). METHODS: Using cre-loxp technique, we created an Ad-myr-HA-Akt virus, in which Akt is labeled by a HA tag and its expression is driven by myr promoter. Further, through measuring enzyme levels and histological structure, we determined the efficacy of this Ad-myr-HA-Akt virus in inhibiting the development of cirrhosis induced by CCl4 in rats. Lastly, using western blotting, we examined the expression levels and/or phosphorylation status of Akt, apoptotic mediators, endothelial nitric oxide synthase (eNOS), and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus. RESULTS: The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment, which was consistent with the sequence reported in the GenBank. The concentrations of Ad-myr-HA-Akt and adenoviral enhanced green fluorescent protein (Ad-EGFP) virus used in the current study were 5.5 × 1011 vp/mL. The portal vein diameter, peak velocity of blood flow, portal blood flow and congestion index were significantly increased in untreated, saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection. In contrast, these parameters in the Akt cirrhosis group were comparable to normal control group. Compared to the normal control, the liver function (Alanine aminotransferase, Aspartate aminotransferase and Albumin) was significantly impaired in the untreated, saline and Ad-EGFP cirrhosis groups. The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated, saline and Ad-EGFP cirrhosis groups. The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups

  12. PRODUCTION OF URANIUM TETRACHLORIDE

    DOEpatents

    Calkins, V.P.

    1958-12-16

    A process is descrlbed for the production of uranium tetrachloride by contacting uranlum values such as uranium hexafluoride, uranlum tetrafluoride, or uranium oxides with either aluminum chloride, boron chloride, or sodium alumlnum chloride under substantially anhydrous condltlons at such a temperature and pressure that the chlorldes are maintained in the molten form and until the uranium values are completely converted to uranlum tetrachloride.

  13. Characterization of Carbon Onion Nanomaterials for Environmental Remediation

    NASA Astrophysics Data System (ADS)

    Li, Y.; Su, C.; Bailes, A.; Lu, Y.

    2009-12-01

    The unique properties of carbonaceous nanomaterials, including small particle size, high surface area, and manipulatable surface chemistry, provide high potential for their applications to environmental remediation. While research has been devoted to develop nanotechnology for environmental applications using carbonaceous nanomaterials, e.g. carbon nanotubes and C60 fullerenes, the practical applications are limited due to their high cost of production of about 50-100/g. We introduce a relatively new carbonaceous nanomaterial, i.e. carbon onion nanomaterials, which could be produced in a cost-effective way of about 1/g, by oxygen-depleted combustion of hydrocarbon gases. Carbon onion nanomaterials consist of spherical fullerene cores surrounded by onion-like nested spherical graphite layers, with diameters of around 20 nm. In this work, we characterized the properties of carbon onion nanomaterials to investigate their potential applications in environmental remediation. Dry carbon onion powders were first characterized using transmission electron microcopy (TEM), X-ray diffraction (XRD), and gas sorption Surface Area Analyzer. Sorption capacity of carbon onion nanomaterials for heavy metals, including Zn(II), Ni(II), Pb(II), Cd(II), and Cu(II), was explored using different pH conditions and surface modification approaches. We found that carbon onion nanomaterials can effectively adsorb heavy metal contaminants at high pH or when surface functionalized with carboxylate groups. Stable aqueous suspension of carbon onion aggregates was produced by exchange of toluene organic solvent. The properties of carbon onion aggregates in aqueous suspension, including particle size, zeta potential, and concentration, were determined using a Zetasizer Nano ZS analyzer, Scanning Electron Microscope (SEM) / Energy-Dispersive X-Ray (EDX), and UV-VIS Scanning Spectrophotometer. Carbon onion nanomaterials were found to be very well dispersed in aqueous phase, forming stable aggregates

  14. Refined conceptual model for the Volatile Organic Compounds-Arid Integrated Demonstration and 200 West Area Carbon Tetrachloride Expedited Response Action

    SciTech Connect

    Last, G.V.; Rohay, V.J.

    1993-03-01

    This report presents a refined geohydrologic and geochemical conceptual model of the host site (Hanford Reservation) for the Volatile Organic Compounds -- Arid Integrated Demonstration (VOC-Arid ID) and 200 West Area Carbon Tetrachloride (CCl{sub 4}) Expedited Response Action (ERA), based on the results from fiscal year 1992 site characterization activities. The ERA was initiated in December 1990 to minimize or stabilize CCl{sub 4} migration within the unsaturated (vadose) zone in the vicinity of three CCl{sub 4} disposal sites in the 200 West Area (216-Z-1A tile field, 216-Z-9 trench, and 216-Z-18 crib). Implementation of this ERA was based on concerns that CCl{sub 4} residing in the soils was continuing to spread to the groundwater and, if left unchecked, would significantly increase the area of groundwater contamination. A soil-vapor-extraction system began operating at the site in February 1992.

  15. Therapeutic administration of an ingredient of aged-garlic extracts, S-allyl cysteine resolves liver fibrosis established by carbon tetrachloride in rats.

    PubMed

    Kodai, Shintaro; Takemura, Shigekazu; Kubo, Shoji; Azuma, Hideki; Minamiyama, Yukiko

    2015-05-01

    S-allyl cysteine (SAC) is the most abundant compound in aged garlic extracts (AGEs). AGE has been reported to ameliorate the oxidative damage implicated in a variety of diseases. However, the effects of SAC have not been established in liver cirrhosis. The aim of this study was to examine the effect of therapeutic administration of SAC in liver cirrhosis by chronic carbon tetrachloride (CCl4) administration in rats. SAC or other cysteine compounds were administered from 4 weeks when liver fibrosis was confirmed to be in process. CCl4 administration elevated plasma alanine aminotransferase, plasma lipid peroxidation, liver hydroxyproline, and liver transforming growth factor (TGF)-β at 12 weeks. SAC prevented these changes induced by CCl4. Furthermore, SAC improved survival in a dose-dependent manner following consecutive CCl4 administration. The inhibitory mechanisms may be associated with a decrease in the profibrogenic cytokine, TGF-β as well as the antioxidative properties of SAC. PMID:26060347

  16. Toll like receptor 2 knock-out attenuates carbon tetrachloride (CCl4)-induced liver fibrosis by downregulating MAPK and NF-κB signaling pathways.

    PubMed

    Ji, Lingling; Xue, Ruyi; Tang, Wenqing; Wu, Weibin; Hu, Tingting; Liu, Xijun; Peng, Xiaomin; Gu, Jianxin; Chen, She; Zhang, Si

    2014-06-01

    Innate immune signaling associated with Toll-like receptors (TLRs) is a key pathway involved in the progression of liver fibrosis. In this study, we reported that TLR2 is required for hepatic fibrogenesis induced by carbon tetrachloride (CCl4). After CCl4 treatment, TLR2(-/-) mice had reduced liver enzyme levels, diminished collagen deposition, decreased inflammatory infiltration and impaired activation of hepatic stellate cells (HSCs) than wild type (WT) mice. Furthermore, after CCl4 treatment, TLR2(-/-) mice demonstrated downregulated expression of profibrotic and proinflammatory genes and impaired mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB) activation than WT mice. Collectively, our data indicate that TLR2 deficiency protects against CCl4-induced liver fibrosis.

  17. An in vivo and in vitro investigation on hepatoprotective effects of Pimpinella anisum seed essential oil and extracts against carbon tetrachloride-induced toxicity

    PubMed Central

    Jamshidzadeh, Akram; Heidari, Reza; Razmjou, Mojtaba; Karimi, Forouzan; Moein, Mahmood Reza; Farshad, Omid; Akbarizadeh, Amin Reza; Shayesteh, Mohammad Reza Houshangi

    2015-01-01

    Objective(s): Protective effects of different extracts and essential oil from Pimpinella anisum L. seeds were examined against carbon tetrachloride (CCl4)-induced toxicity. The parameters such as serum transaminases, lactate dehydrogenase activity, hepatic glutathione content, liver lipid peroxidation and histopathological changes of liver were assessed as toxicity markers. In the in vitro model of this study, markers such as cell viability, cellular reduced and oxidized glutathione and lipid peroxidation in HepG2 cells were evaluated. Materials and Methods: Human liver cancer cell line HepG2 and male Sprague-Dawley rats were treated with extracts and essential oil, and markers of hepatotoxicity were investigated. Results: The data revealed that the n-hexane extract, effectively attenuated CCl4-induced toxicity in both in vitro and in vivo models in current investigation. Conclusion: As the oxidative stress markers were ameliorated, it might be concluded that anise seed possesses protective effects probably due to its antioxidant constituents. PMID:25825639

  18. Use of 13C Labeled Carbon Tetrachloride to Demonstrate the Transformation to Carbon Dioxide under Anaerobic Conditions in a Continuous Flow Column

    NASA Astrophysics Data System (ADS)

    Semprini, L.; Azizian, M.

    2012-12-01

    The demonstration of transformation of chlorinated aliphatic compounds (CAHs) in the subsurface is a challenge, especially when the products are carbon dioxide (CO2) and chloride ion. The groundwater contaminant carbon tetrachloride (CT) is of particular interest since a broad range of transformation products can be potentially formed under anaerobic conditions. The ability to demonstrate the transformation of CT to CO2 as a non toxic endproduct, is also of great interest. Results will be presented from a continuous flow column study where 13C labeled CT was used to demonstrate its transformation to CO2. The column was packed with a quartz sand and bioaugmented the Evanite Culture (EV) that is capable of transforming tetrachloroethene (PCE) to ethene. The column was continously fed a synthetic groundwater that was amended with PCE (0.10 mM) and either formate (1.5 mM) or lactate (1.1 mM), which ferments to produce hydrogen (H2) as the ultimate electron donor. Earlier CT transformation studies with the column, in the absence of sulfate reduction, and with formate added as a donor found CT (0.015 mM) was over 98% transformed with about 20% converted to chloroform (CF) (0.003 mM) and with a transient detection of chloromethane (CM). Methane and carbon disulfide, as potential products, were not detected. Neither CT nor CF inhibited the reductive dehalogenation of PCE to ethene. A series of transient studies conducted after these initial CT transformation tests, but in the absence of CT, showed formate remained an effective substrate for maintaining sulfate reduction and PCE transformation. Lactate, which was effectively fermented prior to CT addition, was not effectively fermented, with propionate accumulating as a fermentation product. When lactate was added, PCE was mainly transformed to cis-dichloroethene (cis-DCE) and VC, and sulfate reduction did not occur. In order to restore effective lactate fermentation the column was then bioaugmented with an EV culture that

  19. Treatability Test Report: Characterization of Vadose Zone Carbon Tetrachloride Source Strength Using Tomographic Methods at the 216-Z-9 Site

    SciTech Connect

    Truex, Michael J.; Carroll, Kenneth C.; Rohay, Virginia J.; Mackley, Rob D.; Parker, Kyle R.

    2012-09-28

    A treatability test was conducted in 2011 at the 216-Z-9 Trench to evaluate methods for collecting characterization information that supports refined assessment of SVE performance goals based on impact to groundwater. The characterization information can also provide input to operational strategies for continued SVE operation and decisions regarding closure of the SVE system or transition to other remedies, if necessary.

  20. Protective Effects of Silymarin, Alone or in Combination with Chlorogenic Acid and/or Melatonin, Against Carbon Tetrachloride-induced Hepatotoxicity

    PubMed Central

    Al-Rasheed, Nouf; Faddah, Laila; Al-Rasheed, Nawal; Bassiouni, Yieldez A.; Hasan, Iman H.; Mahmoud, Ayman M.; Mohamad, Raeesa A.; Yacoub, Hazar I.

    2016-01-01

    Objective: The aim of this study was to evaluate the hepatoprotective effects of silymarin (SIL), alone and combined with chlorogenic acid (CA) and/or melatonin (ME), using a rat model of carbon tetrachloride (CCl4)-induced injury. Materials and Methods: Hepatotoxicity was induced by a single dose of CCl4 (1 ml/kg, IP). One day after, rats were received SIL (200 mg/kg) alone or in combination with CA (60 mg/kg) and/or ME (20 mg/kg) for 21 days. Results: SIL significantly decreased serum alanine aminotransferase, inflammatory cytokines, and vascular endothelial growth factor levels. Histological alterations, fibrogenesis, oxidative DNA damage, inflammatory mediators, and caspase-3 activity were significantly attenuated in SIL treated CCl4-intoxicated rats. On the other hand, cytochrome P450 2E1 activity showed a significant decrease in the liver of CCl4-intoxicated rats, an effect that was reversed following treatment with SIL. All beneficial effects of SIL were markedly potentiated when combined with CA and/or ME. Conclusions: These data indicate that SIL, alone and combined with CA and/or ME, protected the liver against CCl4-induced hepatotoxicity via attenuating inflammation, oxidative DNA damage, apoptosis, and fibrotic changes. The significantly intensified hepatoprotective effects of SIL when combined with both CA and ME suggest a possible synergism. These synergistic effects need to be further confirmed using detailed studies. SUMMARY Silymarin, chlorogenic acid and melatonin possess in vivo hepatoprotective activitySilymarin, chlorogenic acid and melatonin attenuate fibrogenesis, oxidative DNA damage, inflammation and apoptosisChlorogenic acid and melatonin enhance the hepatoprotective effect of silymarin. Abbreviations used: SIL: silymarin, CA: chlorogenic acid, ME: melatonin, CCl4: carbon tetrachloride, CYP2E1, cytochrome P450 2E1, ALT: alanine aminotransferase, IL-6: interleukin 6, IFN-γ: interferon gamma, VEGF: vascular endothelial growth factor, TNF

  1. METHOD FOR PRODUCING DIBORON TETRACHLORIDE

    DOEpatents

    Frazer, J.W.; Holzmann, R.T.

    1961-08-01

    A method of producing diboron tetrachloride from boron trichloride is described. Gaseous boron trichloride is passed through a cavity resonating at a microwave frequency whereby a portion of the boron trichloride is converted into diboron tetrachloride. The diboron tetrachloride may then be separated from the boron trichloride by conventional means. (AEC)

  2. Bacterial remediation from effluent containing multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Lemes, A. P.; Cordi, L.; Santos, A.; Durán, N.

    2011-07-01

    Multi-wall carbon nanotubes (MWCNT) were functionalized with functional groups containing oxygen, mainly carboxylic groups (-COOH), through reaction with a mixture of H2SO4/HNO3 (3:1 v/v). The oxidized multi-wall carbon nanotubes (MWCNTOOH) were used to prepare an effluent, 2 mg L-1 in a saline solution of NaCl (0.9%), to study of remediation of MWCNTOOH in aqueous suspension by utilization of Escherichia coli. The suspensions of E. coli (4.5 × 105 CFU mL-1 and 4.5 × 108 CFU mL-1) in test tubes with MWCNTOOH effluent caused the precipitation of a large amount of MWCNTOOH and supernatant clearing. The scanning electron microscopy (SEM) analysis of the precipitate and supernatant showed the adhesion and interlace of MWCNTOOH in bacteria surface. Although the precipitate consist of a large quantity of MWCNTOOH and bacteria, it was verified their presence in the supernatant. The spread plate technique showed that MWCNTOOH caused no cellular death of E. coli in the supernatant.

  3. Effect of dill tablet (Anethum graveolens L) on antioxidant status and biochemical factors on carbon tetrachloride-induced liver damage on rat

    PubMed Central

    Oshaghi, Ebrahim Abbasi; Khodadadi, Iraj; Tavilani, Heidar; Goodarzi, Mohammad Taghi

    2016-01-01

    Background: Liver damage induced by carbon tetrachloride (CCl4) has been presented as an experimental model for research in hepatoprotective effects of natural product. A commercial medicine prepared from Anethum graveolens L (dill) is being used as dill tablet (DT) as a hypolipidemic agent. This experiment aimed to investigate the protective effect of DT against hepatic damage. Materials and Methods: Male Wistar rats were randomly divided into four groups (n = 6) as following for a 10 days experiments. (1) Normal animals; (2) normal animals +CCl4 1 ml/kg (1:1 of CCl4 in olive oil, by gastric tube); (3) CCl4 treated animals +100 mg DT/kg; (4) CCl4 treated animals +300 mg DT/kg. After 10 days of treatment, biochemical factors were measured; also antioxidant tests such as thiol group, malondialdehyde (MDA), total antioxidant capacity (TAC), and catalase (CAT) activity in the liver samples were carried out. Results: In dill treated animals, a significant decrease in liver enzymes lactate dehydrogenase, alkaline phosphatase, aspartate transaminase, alanine transaminase, γ-glutamyl transferase, total bilirubin, direct bilirubin, as well as triglyceride, total cholesterol (P < 0.05) were observed. Total protein and albumin concentrations were significantly increased in dill treated groups (P < 0.05). Furthermore, treatment with dill declined liver cholesterol, triglyceride, MDA, and increased TAC and CAT activity compared with untreated group (P < 0.05). Conclusion: Dill displayed a potential hepatoprotective effect against CCl4-induced liver damage based on both biochemical markers and antioxidant status. PMID:27127740

  4. Umbelliferone and daphnetin ameliorate carbon tetrachloride-induced hepatotoxicity in rats via nuclear factor erythroid 2-related factor 2-mediated heme oxygenase-1 expression.

    PubMed

    Mohamed, Mohamed R; Emam, Manal A; Hassan, Nahla S; Mogadem, Abeer I

    2014-09-01

    Among various phytochemicals, coumarins comprise a very large class of plant phenolic compounds that have good nutritive value, in addition to their antioxidant effects. The purpose of the present study was to investigate the protective effects of two coumarin derivatives, umbelliferone and daphnetin, against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats and elucidate the underlying mechanism. Treatment of rats with either umbelliferone or daphnetin significantly improved the CCl4-induced biochemical alterations. In addition, both compounds alleviated the induced-lipid peroxidation and boosted the antioxidant defense system. Moreover, the investigated compounds attenuated CCl4-induced histopathological alterations of the liver. Finally, umbelliferone and daphnetin induced the nuclear translocation of the nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), thereby inducing the expression and activity of the cytoprotective heme oxygenase-1 (HO-1). These results suggest that umbelliferone and daphnetin ameliorate oxidative stress-related hepatotoxicity via their ability to augment cellular antioxidant defenses by activating Nrf2-mediated HO-1 expression.

  5. The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects.

    PubMed

    Hamed, Sherifa S; Al-Yhya, Nouf A; El-Khadragy, Manal F; Al-Olayan, Ebtesam M; Alajmi, Reem A; Hassan, Zeinab K; Hassan, Salwa B; Abdel Moneim, Ahmed E

    2016-01-01

    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds. PMID:27547187

  6. UV Absorption Cross Sections of Nitrous Oxide (N2O) and Carbon Tetrachloride (CCl4) Between 210 and 350 K and the Atmospheric Implications

    NASA Technical Reports Server (NTRS)

    Carlon, Nabilah Rontu; Papanastasiou, Dimitrios K.; Fleming, Eric L.; Jackman, Charles H.; Newman, Paul A.; Burkholder, James B.

    2010-01-01

    Absorption cross sections of nitrous oxide (N2O) and carbon tetrachloride (CCl4) are reported at five atomic UV lines (184.95, 202.548, 206.200, 213.857, and 228.8 nm) at 27 temperatures in the range 210-350 K. In addition, UV absorption spectra of CCl4 are reported between 200-235 nm as a function of temperature (225-350 K). The results from this work are critically compared with results from earlier studies. For N2O, the present results are in good agreement with the current JPL recommendation enabling a reduction in the estimated uncertainty in the N2O atmospheric photolysis rate. For CCl4, the present cross section results are systematically greater than the current recommendation at the reduced temperatures most relevant to stratospheric photolysis. The new cross sections result in a 5-7% increase in the modeled CCl4 photolysis loss, and a slight decrease in the stratospheric lifetime, from 51 to 50 years, for present day conditions. The corresponding changes in modeled inorganic chlorine and ozone in the stratosphere are quite small. A CCl4 cross section parameterization for use in 37 atmospheric model calculations is presented.

  7. Negundoside, an iridiod glycoside from leaves of Vitex negundo, protects human liver cells against calcium-mediated toxicity induced by carbon tetrachloride

    PubMed Central

    Tasduq, Sheikh A; Kaiser, Peerzada J; Gupta, Bishan D; Gupta, Vijay K; Johri, Rakesh K

    2008-01-01

    AIM: To evaluate the protective effect of 2'-p-hydroxybenzoylmussaenosidic acid [negundoside (NG), against carbon tetrachloride (CCl4)-induced toxicity in HuH-7 cells. METHODS: CCl4 is a well characterized hepatotoxin, and inducer of cytochrome P450 2E1 (CYP2E1)-mediated oxidative stress. In addition, lipid peroxidation and accumulation of intracellular calcium are important steps in the pathway involved in CCl4 toxicity. Liver cells (HuH-7) were treated with CCl4, and the mechanism of the cytoprotective effect of NG was assessed. Silymarin, a known hepatoprotective drug, was used as control. RESULTS: NG protected HuH-7 cells against CCl4 toxicity and loss of viability without modulating CYP2E1 activity. Prevention of CCl4 toxicity was associated with a reduction in oxidative damage as reflected by decreased generation of reactive oxygen species (ROS), a decrease in lipid peroxidation and accumulation of intracellular Ca2+ levels and maintenance of intracellular glutathione homeostasis. Decreased mitochondrial membrane potential (MMP), induction of caspases mediated DNA fragmentation and cell cycle arrest, as a result of CCl4 treatment, were also blocked by NG. The protection afforded by NG seemed to be mediated by activation of cyclic adenosine monophosphate (cAMP) synthesis and inhibition of phospholipases (cPLA2). CONCLUSION: NG exerts a protective effect on CYP2E1-dependent CCl4 toxicity via inhibition of lipid peroxidation, followed by an improved intracellular calcium homeostasis and inhibition of Ca2+-dependent proteases. PMID:18595136

  8. Protective action of the immunomodulator ginsan against carbon tetrachloride-induced liver injury via control of oxidative stress and the inflammatory response

    SciTech Connect

    Shim, Ji-Young; Kim, Mi-Hyoung; Kim, Hyung-Doo; Ahn, Ji-Yeon; Yun, Yeon-Sook; Song, Jie-Young

    2010-02-01

    The aim of the present study was to evaluate immunomodulator ginsan, a polysaccharide extracted from Panax ginseng, on carbon tetrachloride (CCl{sub 4})-induced liver injury. BALB/c mice were injected i.p. with ginsan 24 h prior to CCl{sub 4} administration. Serum liver enzyme levels, histology, expression of antioxidant enzymes, and several cytokines/chemokines were subsequently evaluated. Ginsan treatment markedly suppressed the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and hepatic histological necrosis increased by CCl{sub 4} treatment. Ginsan inhibited CCl{sub 4} induced lipid peroxidation through the cytochrome P450 2E1 (CYP2E1) downregulation. The hepatoprotective effect of ginsan was attributed to induction of anti-oxidant protein contents, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) as well as restoration of the hepatic glutathione (GSH) concentration. The marked increase of proinflammatory cytokines (IL-1beta, IFN-gamma) and chemokines (MCP-1, MIP-2beta, KC) in CCl{sub 4} treated mice was additionally attenuated by ginsan, thereby preventing leukocyte infiltration and local inflammation. Our results suggest that ginsan effectively prevent liver injury, mainly through downregulation of oxidative stress and inflammatory response.

  9. Effectiveness of cinnamon (Cinnamomum zeylanicum) bark oil in the prevention of carbon tetrachloride-induced damages on the male reproductive system.

    PubMed

    Yüce, A; Türk, G; Çeribaşı, S; Güvenç, M; Çiftçi, M; Sönmez, M; Özer Kaya, Ş; Çay, M; Aksakal, M

    2014-04-01

    In this study, it was aimed to investigate the likelihood of detrimental effects of carbon tetrachloride (CCl4 ) on male reproductive system through oxidative stress mechanism and also protective effects of cinnamon bark oil (CBO). For this purpose, 28 healthy male Wistar rats were divided into four groups, seven rats in each. Group 1 received only olive oil daily; group 2 was treated with 100 mg kg(-1) CBO daily; group 3 was treated with only 0.25 ml kg(-1) CCl4 weekly; and group 4 received weekly CCl4 + daily CBO. All administrations were made by intragastric catheter and maintained for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular oxidative stress markers and testicular apoptosis were examined. CCl4 administration caused significant decreases in body and reproductive organ weights, testicular catalase (CAT) activity, sperm motility and concentration, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and apoptotic index along with some histopathological damages compared with the control group. However, significant improvements were observed in absolute weights of testis and epididymis, all sperm quality parameters, LPO level, apoptotic index and testicular histopathological structure following the administration of CCl4 together with CBO when compared to group given CCl4 only. The findings of this study clearly suggest that CBO has protective effect against damages in male reproductive organs and cells induced by CCl4 .

  10. Impact of a CXCL12/CXCR4 Antagonist in Bleomycin (BLM) Induced Pulmonary Fibrosis and Carbon Tetrachloride (CCl4) Induced Hepatic Fibrosis in Mice.

    PubMed

    Chow, Leola N; Schreiner, Petra; Ng, Betina Y Y; Lo, Bernard; Hughes, Michael R; Scott, R Wilder; Gusti, Vionarica; Lecour, Samantha; Simonson, Eric; Manisali, Irina; Barta, Ingrid; McNagny, Kelly M; Crawford, Jason; Webb, Murray; Underhill, T Michael

    2016-01-01

    Modulation of chemokine CXCL12 and its receptor CXCR4 has been implicated in attenuation of bleomycin (BLM)-induced pulmonary fibrosis and carbon tetrachloride (CCl4)-induced hepatic injury. In pulmonary fibrosis, published reports suggest that collagen production in the injured lung is derived from fibrocytes recruited from the circulation in response to release of pulmonary CXCL12. Conversely, in hepatic fibrosis, resident hepatic stellate cells (HSC), the key cell type in progression of fibrosis, upregulate CXCR4 expression in response to activation. Further, CXCL12 induces HSC proliferation and subsequent production of collagen I. In the current study, we evaluated AMD070, an orally bioavailable inhibitor of CXCL12/CXCR4 in alleviating BLM-induced pulmonary and CCl4-induced hepatic fibrosis in mice. Similar to other CXCR4 antagonists, treatment with AMD070 significantly increased leukocyte mobilization. However, in these two models of fibrosis, AMD070 had a negligible impact on extracellular matrix deposition. Interestingly, our results indicated that CXCL12/CXCR4 signaling has a role in improving mortality associated with BLM induced pulmonary injury, likely through dampening an early inflammatory response and/or vascular leakage. Together, these findings indicate that the CXCL12-CXCR4 signaling axis is not an effective target for reducing fibrosis. PMID:26998906

  11. Ethanol extract of Portulaca Oleracea L. reduced the carbon tetrachloride induced liver injury in mice involving enhancement of NF-κB activity

    PubMed Central

    Shi, Hongguang; Liu, Xuefeng; Tang, Gusheng; Liu, Haiyan; Zhang, Yinghui; Zhang, Bo; Zhao, Xuezhi; Wang, Wanyin

    2014-01-01

    Acute hepatic injury causes high morbidity and mortality world-wide. Management of severe acute hepatic failure continues to be one of the most challenging problems in clinical medicine. In present study, carbon tetrachloride (CCl4) was used to induce acute liver damage in mice and the protective effects of ethanol extract of Portulaca Oleracea L. (PO) were examined. The aminotransferase activities were biochemical estimated and the liver damage was tested by morphological histological analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. The role of PO on the activity of NF-κB was determined by luciferase reporter gene assay and immunohistochemistry. The level of p-p65 was tested by western blot. Our results showed that PO administration on mice would decrease the serum aminotransferase level and reduced the liver histological damage. We also found that nuclear translocation of p65 was enhanced in liver tissues of mice treated with PO compared with control animals. In addition, in cultured hepatic cells, PO increased the NF-κB luciferase reporter gene activity and upregulated the level of phosphorylation of p65, but had no effects on mice liver SOD activity and MDA level. Collectively, PO attenuated CCl4 induced mice liver damage by enhancement of NF-κB activity. PMID:25628785

  12. The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects.

    PubMed

    Hamed, Sherifa S; Al-Yhya, Nouf A; El-Khadragy, Manal F; Al-Olayan, Ebtesam M; Alajmi, Reem A; Hassan, Zeinab K; Hassan, Salwa B; Abdel Moneim, Ahmed E

    2016-01-01

    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds.

  13. Cellular distribution of transforming growth factor-beta 1 and procollagen types I, III, and IV transcripts in carbon tetrachloride-induced rat liver fibrosis.

    PubMed Central

    Nakatsukasa, H; Nagy, P; Evarts, R P; Hsia, C C; Marsden, E; Thorgeirsson, S S

    1990-01-01

    The cellular distribution and temporal expression of transcripts from transforming growth factor-beta 1 (TGF-beta 1) and procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) genes were studied in carbon tetrachloride (CCl4)-induced rat liver fibrosis by using in situ hybridization technique. During the fibrotic process, TGF-beta 1 and procollagen genes were similarly and predominantly expressed in Desmin-positive perisinusoidal cells (e.g., fat-storing cells and myofibroblasts) and fibroblasts and their expression continued to be higher than those observed in control rats. These transcripts were also observed in inflammatory cells mainly granulocytes and macrophage-like cells at the early stages of liver fibrosis. The production of extracellular matrix along small blood vessels and fibrous septa coincided with the expression of these genes. Expression of TGF-beta 1 and procollagen genes were not detected in hepatocytes throughout the experiment. No significant differences in cellular distribution or time course of gene expression among procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) were observed. Desmin-positive perisinusoidal cells and fibroblasts appeared to play the principal role in synthesis of collagens in CCl4-induced hepatic fibrosis. The simultaneous expression of TGF-beta 1 and procollagen genes in mesenchymal cells, including Desmin-positive perisinusoidal cells, during hepatic fibrosis suggests the possibility that TGF-beta 1 may have an important role in the production of fibrosis. Images PMID:1693377

  14. The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

    PubMed Central

    Hamed, Sherifa S.; AL-Yhya, Nouf A.; El-Khadragy, Manal F.; Al-Olayan, Ebtesam M.; Alajmi, Reem A.; Hassan, Zeinab K.; Hassan, Salwa B.; Abdel Moneim, Ahmed E.

    2016-01-01

    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds. PMID:27547187

  15. A virus-like particle-based connective tissue growth factor vaccine suppresses carbon tetrachloride-induced hepatic fibrosis in mice.

    PubMed

    Li, Shuang; Lv, Yi-Fei; Su, Hou-Qiang; Zhang, Qian-Nan; Wang, Li-Rong; Hao, Zhi-Ming

    2016-01-01

    Connective tissue growth factor (CTGF) has been recognized as a central mediator and promising therapeutic target in hepatic fibrosis. In this study, we generated a novel virus-like particle (VLP) CTGF vaccine by inserting the 138-159 amino acid (aa) fragment of CTGF into the central c/e1 epitope of C-terminus truncated hepatitis B virus core antigen (HBc, aa 1-149) using a prokaryotic expression system. Immunization of BALB/c mice with the VLP vaccine efficiently elicited the production of anti-CTGF neutralizing antibodies. Vaccination with this CTGF vaccine significantly protected BALB/c mice from carbon tetrachloride (CCl4)-induced hepatic fibrosis, as indicated by decreased hepatic hydroxyproline content and lower fibrotic score. CCl4 intoxication-induced hepatic stellate cell activation was inhibited by the vaccination, as indicated by decreased α-smooth muscle actin expression and Smad2 phosphorylation. Vaccination against CTGF also attenuated the over-expression of some profibrogenic factors, such as CTGF, transforming growth factor-β1, platelet-derived growth factor-B and tissue inhibitor of metalloproteinase-1 in the fibrotic mouse livers, decreased hepatocyte apoptosis and accelerated hepatocyte proliferation in the fibrotic mouse livers. Our results clearly indicate that vaccination against CTGF inhibits fibrogenesis, alleviates hepatocyte apoptosis and facilitate hepatic regeneration. We suggest that the vaccine should be developed into an effective therapeutic measure for hepatic fibrosis. PMID:27562139

  16. [The effect of carbon tetrachloride poisoning on the activity of digestive proteases in rats and correction of the disorders with vegetable oils].

    PubMed

    Esaulenko, E E; Khil'chuk, M A; Bykov, I M

    2013-01-01

    The results of the study of activity of digestive proteases (pepsin, trypsin, chymotrypsin) in homogenates of stomach, pancreas and duodenum in experimental animals have been presented. Rats were exposed to intoxication with carbon tetrachloride (subcutaneous administration of a 50% oil solution of CCl4 in the dose of 0.5 ml per 100 g body weight) for three days and then they were given analysed oils (black nut, walnut and flax oil) intragastrically by gavage at a dose of 0.2 ml per day within 23 days. Pepsin level in gastric mucosa homogenates and chymotrypsin activity in pancreatic homogenates were determined by method of N.P. Pyatnitskiy based on on the ability of enzymes to coagulate dairy-acetate mixture, respectively, at 25 degrees C and 35 degrees C. Trypsin activity in homogenates of pancreatic was determined by method of Erlanger - Shaternikova colorimetrically. It has been established that intoxication with CCl4 decreased the synthesis of proteolytic enzymes of the stomach (by 51%) and pancreas (by 70-78%). Injections of analysed vegetable oils to animals contributed to the normalization of proteolytic enzymes synthesis. The conclusion that there are prospects of using the analysed vegetable oils containing large quantity of polyunsaturated fatty acids (omega-3 and omega-6) for the correction of detected biochemical abnormalities has been done.

  17. A virus-like particle-based connective tissue growth factor vaccine suppresses carbon tetrachloride-induced hepatic fibrosis in mice

    PubMed Central

    Li, Shuang; Lv, Yi-Fei; Su, Hou-Qiang; Zhang, Qian-Nan; Wang, Li-Rong; Hao, Zhi-Ming

    2016-01-01

    Connective tissue growth factor (CTGF) has been recognized as a central mediator and promising therapeutic target in hepatic fibrosis. In this study, we generated a novel virus-like particle (VLP) CTGF vaccine by inserting the 138–159 amino acid (aa) fragment of CTGF into the central c/e1 epitope of C-terminus truncated hepatitis B virus core antigen (HBc, aa 1–149) using a prokaryotic expression system. Immunization of BALB/c mice with the VLP vaccine efficiently elicited the production of anti-CTGF neutralizing antibodies. Vaccination with this CTGF vaccine significantly protected BALB/c mice from carbon tetrachloride (CCl4)-induced hepatic fibrosis, as indicated by decreased hepatic hydroxyproline content and lower fibrotic score. CCl4 intoxication-induced hepatic stellate cell activation was inhibited by the vaccination, as indicated by decreased α-smooth muscle actin expression and Smad2 phosphorylation. Vaccination against CTGF also attenuated the over-expression of some profibrogenic factors, such as CTGF, transforming growth factor-β1, platelet-derived growth factor-B and tissue inhibitor of metalloproteinase-1 in the fibrotic mouse livers, decreased hepatocyte apoptosis and accelerated hepatocyte proliferation in the fibrotic mouse livers. Our results clearly indicate that vaccination against CTGF inhibits fibrogenesis, alleviates hepatocyte apoptosis and facilitate hepatic regeneration. We suggest that the vaccine should be developed into an effective therapeutic measure for hepatic fibrosis. PMID:27562139

  18. Chloroquine improved carbon tetrachloride-induced liver fibrosis through its inhibition of the activation of hepatic stellate cells: role of autophagy.

    PubMed

    He, Wei; Wang, Bin; Yang, Jing; Zhuang, Yun; Wang, Liangzhi; Huang, Xiaodan; Chen, Jianping

    2014-01-01

    Autophagy is involved in the activation of hepatic stellate cells (HSCs), which is the key process of liver fibrosis. We reasoned that chloroquine, based on its ability to inhibit autophagy, might exert beneficial effects in liver fibrosis. Liver fibrosis in rats was induced by carbon tetrachloride (CCl4). Rats were divided into three groups, a normal control group (N group), model group (M group), and chloroquine group (CQ group). Liver fibrosis in the rats was evaluated by hematoxyline-eosin (H&E) and Masson staining. The activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) were determined using an automated biochemistry analyzer. Total hepatic hydroxyproline levels were determined with a kit. The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were detected by immunofluorescence staining, and the expressions of LC3-II and p62 were determined by Western blotting. Compared with N group, M group showed impaired liver function, liver fibrosis, increased hydroxyproline content, up-regulated expressions of α-SMA and TGF-β1, which have been reported to be pro-fibrogenic genes in vivo, and increased autophagy flux as indicated by the accumulation of LC3-II and degradation of p62. These changes were attenuated by chloroquine treatment. Chloroquine exerts beneficial effects in CCl4-induced liver fibrosis. The mechanism of action includes inhibition of autophagy pathways and inhibition of activation of HSCs. PMID:25177034

  19. Hepatoprotective Effect of Wheat-Based Solid-State Fermented Antrodia cinnamomea in Carbon Tetrachloride-Induced Liver Injury in Rat

    PubMed Central

    Chiu, Huan-Wen; Hua, Kuo-Feng

    2016-01-01

    Antrodia cinnamomea (A. cinnamomea) is an indigenous medical fungus in Taiwan and has multiple biological functions, including hepatoprotective and immune-modulatory effects. Currently, the commercially available A. cinnamomea are mainly liquid- and solid-state fermented A. cinnamomea. However, the hepatoprotective effect of solid-state fermented A. cinnamomea has never been reported. Here we evaluate the ability of air-dried, ground and non-extracted wheat-based solid-state fermented A. cinnamomea (WFAC) to protect against carbon tetrachloride (CCl4)-induced hepatic injury in vivo. The results showed that oral administration of WFAC dose dependently (180, 540 and 1080 mg/kg) ameliorated the increase in plasma aspartate aminotransferase and alanine aminotransferase levels caused by chronic repeated CCl4 intoxication in rats. WFAC significantly reduced the CCl4-induced increase in hepatic lipid peroxidation levels and hydroxyproline contents, as well as reducing the spleen weight and water content of the liver. WFAC also restored the hepatic soluble protein synthesis and plasma albumin concentration in CCl4-intoxicated rats, but it did not affect the activities of superoxide dismutase, catalase, or glutathione peroxidase. In addition, a hepatic morphological analysis showed that the hepatic fibrosis and necrosis induced by CCl4 were significantly ameliorated by WFAC. Furthermore, the body weights of control rats and WFAC-administered rats were not significantly different, and no adverse effects were observed in WFAC-administered rats. These results indicate that WFAC is a nontoxic hepatoprotective agent against chronic CCl4-induced hepatic injury. PMID:27046059

  20. Hepatoprotective Effect of Wheat-Based Solid-State Fermented Antrodia cinnamomea in Carbon Tetrachloride-Induced Liver Injury in Rat.

    PubMed

    Chiu, Huan-Wen; Hua, Kuo-Feng

    2016-01-01

    Antrodia cinnamomea (A. cinnamomea) is an indigenous medical fungus in Taiwan and has multiple biological functions, including hepatoprotective and immune-modulatory effects. Currently, the commercially available A. cinnamomea are mainly liquid- and solid-state fermented A. cinnamomea. However, the hepatoprotective effect of solid-state fermented A. cinnamomea has never been reported. Here we evaluate the ability of air-dried, ground and non-extracted wheat-based solid-state fermented A. cinnamomea (WFAC) to protect against carbon tetrachloride (CCl4)-induced hepatic injury in vivo. The results showed that oral administration of WFAC dose dependently (180, 540 and 1080 mg/kg) ameliorated the increase in plasma aspartate aminotransferase and alanine aminotransferase levels caused by chronic repeated CCl4 intoxication in rats. WFAC significantly reduced the CCl4-induced increase in hepatic lipid peroxidation levels and hydroxyproline contents, as well as reducing the spleen weight and water content of the liver. WFAC also restored the hepatic soluble protein synthesis and plasma albumin concentration in CCl4-intoxicated rats, but it did not affect the activities of superoxide dismutase, catalase, or glutathione peroxidase. In addition, a hepatic morphological analysis showed that the hepatic fibrosis and necrosis induced by CCl4 were significantly ameliorated by WFAC. Furthermore, the body weights of control rats and WFAC-administered rats were not significantly different, and no adverse effects were observed in WFAC-administered rats. These results indicate that WFAC is a nontoxic hepatoprotective agent against chronic CCl4-induced hepatic injury. PMID:27046059

  1. Amelioration of oxidative stress by dandelion extract through CYP2E1 suppression against acute liver injury induced by carbon tetrachloride in Sprague-Dawley rats.

    PubMed

    Park, Chung Mu; Cha, Yeon Suk; Youn, Hyun Joo; Cho, Chung Won; Song, Young Sun

    2010-09-01

    The protective effects of common dandelion leaf water extract (DLWE) were investigated by carbon tetrachloride (CCl4) induced hepatitis in Sprague-Dawley rats. The animals were divided into five groups: normal control, DLWE control, CCl4 control, and two DLWE groups (0.5 and 2 g/kg bw). After 1 week of administering corresponding vehicle or DLWE, a single dose of CCl4 (50% CCl4/olive oil; 0.5 mL/kg bw) was administered 24 h before killing in order to produce acute liver injury. The DLWE treatment significantly decreased CCl4-induced hepatic enzyme activities (AST, ALT and LDH) in a dose dependent manner. Also, the obstructed release of TG and cholesterol into the serum was repaired by DLWE administration. Hepatic lipid peroxidation was elevated while the GSH content and antioxidative enzyme activities were reduced in the liver as a result of CCl4 administration, which were counteracted by DLWE administration. Furthermore, the hepatocytotoxic effects of CCl4 were confirmed by significantly elevated Fas and TNF-α mRNA expression levels, but DLWE down-regulated these expressions to the levels of the normal control. Highly up-regulated cytochrome P450 2E1 was also lowered significantly in the DLWE groups. These results indicate that DLWE has a protective effect against CCl4-induced hepatic damage with at least part of its effect being attributable to the attenuation of oxidative stress and inflammatory processes resulting from cytochrome P450 activation by CCl4.

  2. Activated carbon amendment for in-situ remediation

    NASA Astrophysics Data System (ADS)

    Elmquist, M.; Brändli, R.; Henriksen, T.; Hartnik, T.; Cornelissen, G.

    2009-04-01

    For the first time in Europe, a novel and innovative remediation technique is used in a field pilot study. This technique is amendment of the soil with two types of activated carbon (AC). Here, one pulverized AC (PAC, 50% < 15µm and 3% >150 µm) and one granular AC (GAC, 1.7-0.43 mm) is tested. The idea of this technique is that the added AC binds organic contaminants so strongly that they cannot be taken up in living organisms or transported to other environmental compartments. Laboratory studies with 2% (wt %) AC amendment to an urban soil reduced the freely dissolved pore water concentrations of PAH by 17% to 99% (Brändli et al. 2008). Several parameters such as dissolved organic carbon (DOC), K, NO2, NO3, NH4, PO4 and PAH, are being measured in this field study. Plant growth and earthworm bioaccumulation tests were also carried out during the summer months. DOC showed a 70% reduction between untreated soil and soil with PAC about one year after the amendment. In the soil mixed with GAC, a 55% reduction could be measured. For K, a 40% lowering value was observed for the soil with GAC compared to no affect for the soil with PAC. NH4 was reduced by 50% for both GAC and PAC amended soils compared to the untreated soil, whereas NO2 and NO3 increased with 2-4 times for the soil with GAC and no effect were seen for the soil with PAC. The freely dissolved PAH concentrations were reduced by 49-78% for the soil with GAC and 82-96% for the soil with PAC. The plant experiment showed best growth rate in the soil with GAC, followed by the untreated soil and least growth was measured on the PAC treated soil. The low growth rate seen in the soil with PAC may come from the fact that DOC and some other nutrients are also being sorbed to the PAC surface together with the organic pollutants and are thereby taken away from the biological cycle. Amendment of soil with AC remediates the soil from organic contaminants when these pollutants are sorbed to the AC surface. This is an

  3. Carbon Tetrachloride Flow and Transport in the Subsurface of the 216-Z-9 Trench at the Hanford Site

    NASA Astrophysics Data System (ADS)

    Oostrom, M.; Rockhold, M.; Truex, M.; Thorne, P.; Last, G.; Rohay, V.

    2006-12-01

    Three-dimensional modeling was conducted with layered and heterogeneous models to enhance the conceptual model of CT distribution in the vertical and lateral direction beneath the 216-Z-9 trench and to investigate the effects of soil vapor extraction (SVE). This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy. Simulations targeted migration of dense, nonaqueous phase liquid (DNAPL) consisting of CT and co-disposed organics in the subsurface beneath the 216-Z-9 trench as a function of the properties and distribution of subsurface sediments and of the properties and disposal history of the waste. Simulations of CT migration were conducted using the Subsurface Transport Over Multiple Phases (STOMP) simulator. Simulation results support a conceptual model for CT distribution where CT in the DNAPL phase is expected to have migrated primarily in a vertical direction below the disposal trench. Presence of small-scale heterogeneities tends to limit the extent of vertical migration of CT DNAPL due to enhanced retention of DNAPL compared to more homogeneous conditions, but migration is still predominantly in the vertical direction. Results also show that the Cold Creek units retain more CT DNAPL within the vadose zone than other hydrologic unit during SVE. A considerable amount of the disposed CT DNAPL may have partitioned to the vapor and subsequently water and sorbed phases. Presence of small-scale heterogeneities tends to increase the amount of volatilization. Any continued migration of CT from the vadose zone to the groundwater is likely through interaction of vapor phase CT with the groundwater and not through continued DNAPL migration. The results indicated that SVE appears to be an effective technology for vadose zone remediation, but additional effort is needed to improve simulation of the SVE process.

  4. Biological responses to activated carbon amendments in sediment remediation.

    PubMed

    Janssen, Elisabeth M-L; Beckingham, Barbara A

    2013-07-16

    Sorbent amendment with activated carbon (AC) is a novel in situ management strategy for addressing human and ecological health risks posed by hydrophobic organic chemicals (HOCs) in sediments and soils. A large body of literature shows that AC amendments can reduce bioavailability of sediment-associated HOCs by more than 60-90%. Empirically derived biodynamic models can predict bioaccumulation in benthic invertebrates within a factor of 2, allowing for future scenarios under AC amendment to be estimated. Higher AC dose and smaller AC particle size further reduce bioaccumulation of HOCs but may induce stress in some organisms. Adverse ecotoxicity response to AC exposure was observed in one-fifth of 82 tests, including changes in growth, lipid content, behavior, and survival. Negative effects on individual species and benthic communities appear to depend on the characteristics of the sedimentary environment and the AC amendment strategy (e.g., dose and particle size). More research is needed to evaluate reproductive end points, bacterial communities, and plants, and to link species- and community-level responses to amendment. In general, the ability of AC to effectively limit the mobility of HOCs in aquatic environments may outshine potential negative secondary effects, and these outcomes must be held in comparison to traditional remediation approaches.

  5. Characterization of Carbon Nano-Onions for Heavy Metal Ion Remediation

    EPA Science Inventory

    Carbonaceous nanomaterials, such as fullerene C60, carbon nanotubes, and their functionalized derivatives have been demonstrated to possess high sorption capacity for organic and heavy metal contaminants, indicating a potential for remediation application. The actual application ...

  6. Remediation of Contaminated Soils By Supercritical Carbon Dioxide Extraction

    NASA Astrophysics Data System (ADS)

    Ferri, A.; Zanetti, M. C.; Banchero, M.; Fiore, S.; Manna, L.

    The contaminants that can be found in soils are many, inorganic, like heavy metals, as well as organic. Among the organic contaminants, oil and coal refineries are responsi- ble for several cases of soil contamination with PAHs (Polycyclic Aromatic Hydrocar- bons). Polynuclear aromatic hydrocarbons (PAHs) have toxic, carcinogenic and mu- tagenic effects. Limits have been set on the concentration of most contaminants, and growing concern is focusing on soil contamination issues. USA regulations set the maximum acceptable level of contamination by PAHs equal to 40 ppm at residential sites and 270 ppm at industrial sites. Stricter values are usually adopted in European Countries. Supercritical carbon dioxide extraction is a possible alternative technology to remove volatile organic compounds from contaminated soils. Supercritical fluid extraction (SFE) offers many advantages over conventional solvent extraction. Super- critical fluids combine gaseous properties as a high diffusion coefficient, and liquid properties as a high solvent power. The solvent power is strongly pressure-dependent near supercritical conditions: selective extractions are possible without changing the solvent. Solute can be separate from the solvent depressurising the system; therefore, it is possible to recycle the solvent and recover the contaminant. Carbon dioxide is frequently used as supercritical fluid, because it has moderate critical conditions, it is inert and available in pure form. In this work, supercritical fluid extraction technology has been used to remove a polynuclear aromatic hydrocarbon from contaminated soils. The contaminant choice for the experiment has been naphthalene since several data are available in literature. G. A. Montero et al. [1] studied soil remediation with supercrit- ical carbon dioxide extraction technology; these Authors have found that there was a mass-transfer limitation. In the extraction vessel, the mass transfer coefficient in- creases with the

  7. The protective effects of Curcuma longa Linn. extract on carbon tetrachloride-induced hepatotoxicity in rats via upregulation of Nrf2.

    PubMed

    Lee, Hyeong-Seon; Li, Li; Kim, Hyun-Kyung; Bilehal, Dinesh; Li, Wei; Lee, Dong-Seok; Kim, Yong-Ho

    2010-09-01

    This study was designed to investigate the potentially protective effects of Curcuma longa Linn. extract (CLE) on carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Male Sprague-Dawley rats were pretreated with 50 or 100mg/kg of CLE or 100mg/kg of butylated hydroxytoluene (BHT) for 14 days before CCl4 administration. In addition, the CLE control group was pretreated with 100mg/kg CLE for only 14 days. Three hours after the final treatment, a single dose of CCl4 (20mg/kg) was administrated intraperitoneally to each group. After the completion of this phase of the experiment, food and water were removed 12 h prior to the next step. The rats were then anesthetized by urethane and their blood and liver were collected. It was observed that the aspartate aminotransferase and alanine aminotransferase activities of the serum, and the hepatic malondialdehyde levels had significantly decreased in the CLE group when compared with the CCl4-treated group. The antioxidant activities, such as superoxide dismutase, catalase, and glutathione peroxidase activities, in addition to glutathione content, had increased considerably in the CLE group compared with the CCl4-treated group. Phase II detoxifying enzymes, such as glutathione S-transferase, were found to have significantly increased in the CLE group as opposed to the CCl4-treated group. The content of Nrf2 was determined by Western blot analysis. Pretreated CLE increased the level of nuclear translocated Nrf2, and the Nrf2 then increased the activity of the antioxidant and phase II detoxifying enzymes. These results indicate that CLE has protective effects against CCl4-induced hepatotoxicity in rats, via activities of antioxidant and phase II detoxifying enzymes, and through the activation of nuclear translocated Nrf2. PMID:20890099

  8. Protective effect of a mixture of Aloe vera and Silybum marianum against carbon tetrachloride-induced acute hepatotoxicity and liver fibrosis.

    PubMed

    Kim, Sung-Hwa; Cheon, Ho Jun; Yun, Nari; Oh, Sun-Tack; Shin, Eunju; Shim, Kyu Suk; Lee, Sun-Mee

    2009-01-01

    The hepatoprotective effects of ACTIValoe N-931 complex, a mixture of Aloe vera and Silybum marianum, against acute and chronic carbon tetrachloride (CCl(4))-induced liver injuries were investigated. Acute hepatotoxicity was induced by intraperitoneal injection of CCl(4) (50 microl/kg), and ACTIValoe N-931 complex at 85, 170, and 340 mg/kg was administered orally 48, 24, and 2 h before and 6 h after injection of CCl(4). Hepatotoxicity was assessed 24 h after CCl(4) treatment. Liver fibrosis was induced by intraperitoneal injection of CCl(4) for 8 weeks (0.5 ml/kg, twice per week), and mice were treated with ACTIValoe N-931 complex at 85, 170, or 340 mg/kg once a day (p.o.). In both acute hepatotoxicity and liver fibrosis, serum aminotransferase levels and lipid peroxidation were increased and the hepatic glutathione content was decreased. These changes were prevented by ACTIValoe N-931 complex. The ACTIValoe N-931 complex attenuated the increase in tumor necrosis factor-alpha (TNF-alpha), and inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), mRNA expressions in acute hepatotoxicity. In antifibrotic experiments, tissue inhibitor of metalloprotease-1 (TIMP-1) mRNA expression was attenuated by treatment with ACTIValoe N-931 complex. The ACTIValoe N-931 complex decreased the hepatic hydroxyproline content and the transforming growth factor-beta1 levels. Our results suggest that the ACTIValoe N-931 complex has hepatoprotective effects in both acute and chronic liver injuries induced by CCl(4).

  9. Modulatory potentials of aqueous leaf and unripe fruit extracts of Carica papaya Linn. (Caricaceae) against carbon tetrachloride and acetaminophen-induced hepatotoxicity in rats

    PubMed Central

    Awodele, Olufunsho; Yemitan, Omoniyi; Ise, Peter Uduak; Ikumawoyi, Victor Olabowale

    2016-01-01

    Introduction: Carica papaya Linn is used in a traditional medicine for hepatobiliary disorders. This study investigated the hepatomodulatory effects of aqueous extracts of C. papaya leaf (CPL) and unripe fruit (CPF) at doses of 100 and 300 mg/kg on carbon tetrachloride (CCl4) and acetaminophen (ACM)-induced liver toxicities in rats. Materials and Methods: Rats were administered CCl4 (3 ml/kg in olive oil, i.p.) followed by oral administration of CPL and CPF at 2, 6 and 10 h intervals. The ACM model proceeded with the same method but inclusive of animals treated with N-acetyl cysteine (3 ml/kg i.p). At the end of the study, serum levels of liver biomarkers and antioxidant enzymes were assessed and histology of the liver tissues determined. Results: There was a significant (P < 0.05) reduction in CCl4 and ACM-induced increases in serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and direct bilirubin at 100 and 300 mg/kg, respectively. The levels of catalase (CAT), superoxide dismutase and reduced GSH were decreased in both models with corresponding significantly (P < 0.05) elevated level of malondialdehyde. However, these antioxidant enzymes were significantly (P < 0.05) increased in CPL and CPF-treated rats. Histopathological assessment of the liver confirmed the protective effects of CPL and CPF on CCl4 and ACM-induced hepatic damage evidenced by the normal presentation of liver tissue architecture. Conclusion: These results indicate that aqueous extracts of C. papaya may be useful in preventing CCl4 and ACM-induced liver toxicities. PMID:27069723

  10. The hepatocurative effects of Cynara scolymus L. leaf extract on carbon tetrachloride-induced oxidative stress and hepatic injury in rats.

    PubMed

    Colak, Emine; Ustuner, Mehmet Cengiz; Tekin, Neslihan; Colak, Ertugrul; Burukoglu, Dilek; Degirmenci, Irfan; Gunes, Hasan Veysi

    2016-01-01

    Cynara scolymus is a pharmacologically important medicinal plant containing phenolic acids and flavonoids. Experimental studies indicate antioxidant and hepatoprotective effects of C. scolymus but there have been no studies about therapeutic effects of liver diseases yet. In the present study, hepatocurative effects of C. scolymus leaf extract on carbon tetrachloride (CCl4)-induced oxidative stress and hepatic injury in rats were investigated by serum hepatic enzyme levels, oxidative stress indicator (malondialdehyde-MDA), endogenous antioxidants, DNA fragmentation, p53, caspase 3 and histopathology. Animals were divided into six groups: control, olive oil, CCl4, C. scolymus leaf extract, recovery and curative. CCl4 was administered at a dose of 0.2 mL/kg twice daily on CCl4, recovery and curative groups. Cynara scolymus extract was given orally for 2 weeks at a dose of 1.5 g/kg after CCl4 application on the curative group. Significant decrease of serum alanine-aminotransferase (ALT) and aspartate-aminotransferase (AST) levels were determined in the curative group. MDA levels were significantly lower in the curative group. Significant increase of superoxide dismutase (SOD) and catalase (CAT) activity in the curative group was determined. In the curative group, C. scolymus leaf extract application caused the DNA % fragmentation, p53 and caspase 3 levels of liver tissues towards the normal range. Our results indicated that C. scolymus leaf extract has hepatocurative effects of on CCl4-induced oxidative stress and hepatic injury by reducing lipid peroxidation, providing affected antioxidant systems towards the normal range. It also had positive effects on the pathway of the regulatory mechanism allowing repair of DNA damage on CCl4-induced hepatotoxicity. PMID:27026910

  11. The sympathetic nervous system promotes carbon tetrachloride-induced liver cirrhosis in rats by suppressing apoptosis and enhancing the growth kinetics of regenerating hepatocytes.

    PubMed

    Hamasaki, K; Nakashima, M; Naito, S; Akiyama, Y; Ohtsuru, A; Hamanaka, Y; Hsu, C T; Ito, M; Sekine, I

    2001-02-01

    Norepinephrine is considered to possess potent anti-apoptotic action in regenerating hepatocytes. To clarify the role of the sympathetic nervous system in apoptosis that occurs in chronic liver damage and following the promotion of liver cirrhosis, we studied a carbon tetrachloride (CCl4)-induced liver injury model, using spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY), and chemically sympathectomized WKY. At 24 h after CCl4 administration. acute damage, characterized by vacuolated hepatocytes in the centrilobular zone, was greater in SHR than in WKY. This vacuolated change in WKY hepatocytes was significantly reduced by chemical sympathectomy with 6-hydroxydopamine (6-OHDA). After 48 h, the acute damage was dramatically improved in each animal, without significant differences between the three groups. In chronic damage after weekly repetition of CCl4 treatment for 4 weeks, fibrosis was evident in SHR, while in the other groups there was only scant fibrosis in the centrilobular zone. After 8 weeks' repetition of CCl4, liver cirrhosis was seen only in SHR. The incidence of apoptotic cells in areas of both acute and chronic damage in WKY, detected by terminal deoxynucleotidyl transferase-dUTP nick end labeling, was significantly increased in comparison with that in SHR, and was further increased by 6-OHDA pretreatment. In contrast, there was significantly greater enhancement of the growth of hepatocytes in SHR than in WKY in both acute and chronic damage. Moreover. hepatocyte growth kinetics in WKY was significantly inhibited after sympathectomy in acute injury, as evidenced by immunohistochemistry for proliferating cell nuclear antigen (PCNA). In vitro, the amount of hepatocellular apoptosis induced by transforming growth factor-beta1 was significantly decreased by incubation with norepinephrine. These findings suggest that the anti-apoptotic effect of the sympathetic nervous system increases cell growth kinetics and promotes liver cirrhosis in this

  12. Non-covalent C-Cl…π interaction in acetylene-carbon tetrachloride adducts: Matrix isolation infrared and ab initio computational studies

    NASA Astrophysics Data System (ADS)

    Ramanathan, N.; Sundararajan, K.; Vidya, K.; Jemmis, Eluvathingal D.

    2016-03-01

    Non-covalent halogen-bonding interactions between π cloud of acetylene (C2H2) and chlorine atom of carbon tetrachloride (CCl4) have been investigated using matrix isolation infrared spectroscopy and quantum chemical computations. The structure and the energies of the 1:1 C2H2-CCl4 adducts were computed at the B3LYP, MP2 and M05-2X levels of theory using 6-311 ++G(d,p) basis set. The computations indicated two minima for the 1:1 C2H2-CCl4 adducts; with the C-Cl…π adduct being the global minimum, where π cloud of C2H2 is the electron donor. The second minimum corresponded to a C-H…Cl adduct, in which C2H2 is the proton donor. The interaction energies for the adducts A and B were found to be nearly identical. Experimentally, both C-Cl…π and C-H…Cl adducts were generated in Ar and N2 matrixes and characterized using infrared spectroscopy. This is the first report on halogen bonded adduct, stabilized through C-Cl…π interaction being identified at low temperatures using matrix isolation infrared spectroscopy. Atoms in Molecules (AIM) and Natural Bond Orbital (NBO) analyses were performed to support the experimental results. The structures of 2:1 ((C2H2)2-CCl4) and 1:2 (C2H2-(CCl4)2) multimers and their identification in the low temperature matrixes were also discussed.

  13. Loss of hepatocyte EGFR has no effect alone but exacerbates carbon tetrachloride-induced liver injury and impairs regeneration in hepatocyte Met-deficient mice

    PubMed Central

    Zhang, Xiuqi; Stevenson, Mary C.; Threadgill, David W.; Russell, William E.

    2014-01-01

    The role(s) of the epidermal growth factor receptor (EGFR) in hepatocytes is unknown. We generated a murine hepatocyte specific-EGFR knockout (KO) model to evaluate how loss of hepatocellular EGFR expression affects processes such as EGF clearance, circulating EGF concentrations, and liver regeneration following 70% resection or CCl4-induced centrilobular injury. We were able to disrupt EGFR expression effectively in hepatocytes and showed that the ability of EGF and heregulin (HRG) to phosphorylate EGFR and ERBB3, respectively, required EGFR. Loss of hepatocellular EGFR impaired clearance of exogenous EGF from the portal circulation but paradoxically resulted in reduced circulating levels of endogenous EGF. This was associated with decreased submandibular salivary gland production of EGF. EGFR disruption did not result in increased expression of other ERBB proteins or Met, except in neonatal mice. Liver regeneration following 70% hepatectomy revealed a mild phenotype, with no change in cyclin D1 expression and slight differences in cyclin A expression compared with controls. Peak 5-bromo-2′-deoxyuridine labeling was shifted from 36 to 48 h. Centrilobular damage and regenerative response induced by carbon tetrachloride (CCl4) were identical in the KO and wild-type mice. In contrast, loss of Met increased CCl4-induced necrosis and delayed regeneration. Although loss of hepatocellular EGFR alone did not have an effect in this model, EGFR-Met double KOs displayed enhanced necrosis and delayed liver regeneration compared with Met KOs alone. This suggests that EGFR and Met may partially compensate for the loss of the other, although other compensatory mechanisms can be envisioned. PMID:25414100

  14. The hepatocurative effects of Cynara scolymus L. leaf extract on carbon tetrachloride-induced oxidative stress and hepatic injury in rats.

    PubMed

    Colak, Emine; Ustuner, Mehmet Cengiz; Tekin, Neslihan; Colak, Ertugrul; Burukoglu, Dilek; Degirmenci, Irfan; Gunes, Hasan Veysi

    2016-01-01

    Cynara scolymus is a pharmacologically important medicinal plant containing phenolic acids and flavonoids. Experimental studies indicate antioxidant and hepatoprotective effects of C. scolymus but there have been no studies about therapeutic effects of liver diseases yet. In the present study, hepatocurative effects of C. scolymus leaf extract on carbon tetrachloride (CCl4)-induced oxidative stress and hepatic injury in rats were investigated by serum hepatic enzyme levels, oxidative stress indicator (malondialdehyde-MDA), endogenous antioxidants, DNA fragmentation, p53, caspase 3 and histopathology. Animals were divided into six groups: control, olive oil, CCl4, C. scolymus leaf extract, recovery and curative. CCl4 was administered at a dose of 0.2 mL/kg twice daily on CCl4, recovery and curative groups. Cynara scolymus extract was given orally for 2 weeks at a dose of 1.5 g/kg after CCl4 application on the curative group. Significant decrease of serum alanine-aminotransferase (ALT) and aspartate-aminotransferase (AST) levels were determined in the curative group. MDA levels were significantly lower in the curative group. Significant increase of superoxide dismutase (SOD) and catalase (CAT) activity in the curative group was determined. In the curative group, C. scolymus leaf extract application caused the DNA % fragmentation, p53 and caspase 3 levels of liver tissues towards the normal range. Our results indicated that C. scolymus leaf extract has hepatocurative effects of on CCl4-induced oxidative stress and hepatic injury by reducing lipid peroxidation, providing affected antioxidant systems towards the normal range. It also had positive effects on the pathway of the regulatory mechanism allowing repair of DNA damage on CCl4-induced hepatotoxicity.

  15. Dose response and time course studies on superoxide dismutase as a urinary biomarker of carbon tetrachloride-induced hepatic injury in the Hanover Wistar rat.

    PubMed

    Smyth, Rosemary; Munday, Michael R; York, Malcolm J; Clarke, Christopher J; Dare, Theo; Turton, John A

    2009-10-01

    Previous studies have shown that the enzyme copper/zinc superoxide dismutase (SOD-1) is increased in the urine of rats with carbon tetrachloride (CCl(4))-induced hepatotoxicity. The present experiments aimed to investigate further the usefulness of urinary SOD-1 as a non-invasive biomarker of liver injury. Two investigations were carried out, a dose response study and a time course study. In the dose response study, rats were given a single dose of CCl(4) at 0 (control), 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40 and 0.80 ml/kg and urine samples collected from 12 to 36 h postdosing. In the time course study, rats were dosed at 0.80 ml/kg CCl(4) and urine sampled at 4, 12, 24 and 36 h postdosing. In both studies, the presence of SOD-1 in the urine was confirmed by Western blotting with an SOD-1 antibody. In the dose response study, serum SOD activity was elevated in all CCl(4)-treated animals and urinary SOD-1 activity was increased 2.2 times at the lowest dose (0.10 ml/kg) and 60.4 times at the highest CCl(4) dose level (0.80 ml/kg). In the time course study, urinary SOD-1 was first detected in samples collected from 4 to 12 h postdosing. We conclude that urinary SOD-1 has potential as a sensitive non-invasive biomarker of CCl(4)-induced hepatocellular injury.

  16. Toxicology studies of a chemical mixture of 25 groundwater contaminants: hepatic and renal assessment, response to carbon tetrachloride challenge, and influence of treatment-induced water restriction.

    PubMed

    Simmons, J E; Yang, R S; Svendsgaard, D J; Thompson, M B; Seely, J C; McDonald, A

    1994-11-01

    Because groundwater contamination is an important environmental concern, we examined the hepatic and renal effects of repeated exposure to a mixture of 25 chemicals frequently found in groundwater near hazardous-waste disposal sites and the effect of such exposure on carbon tetrachloride (CCI4) toxicity. Adult male F-344 rats received ad libitum deionized water and feed (Ad Lib Water) or ad libitum 10% MIX (referring to 10% of a technically achievable stock mixture) and feed for 14 d. Because exposure to the 25-chemical mixture via the drinking water resulted in decreased water and feed consumption, restricted deionized water and feed controls (Restricted Water) were included. On d 14, rats were gavaged with 0, 0.0375, 0.05, 0.075 or 0.15 ml CCl4/kg, and hepatic and renal toxicity assessed 24 h later. Little or no hepatic and renal toxicity was observed in rats exposed to 10% MIX alone. No hepatic or renal lesions occurred that could be attributed to 10% MIX alone. Slight but statistically significant alterations, of uncertain biological significance, resulted from the water treatments: 10% MIX increased alanine aminotransferase, urea nitrogen (BUN), and BUN/creatinine ratio; Restricted Water increased 5'-nucleotidase and decreased alkaline phosphatase. Relative kidney weight was increased by both 10% MIX and Restricted Water. CCI4 resulted in significant dosage-dependent hepatotoxicity in all three water treatment groups but had little or no effect on renal indicators of toxicity. Relative to Ad Lib Water, significantly greater hepatotoxicity occurred in both 10% MIX and Restricted Water rats. The response to CCI4 in the Restricted Water rats was similar to that of 10% MIX rats, indicating that a substantial portion of the effect of 10% MIX on CCI4 hepatotoxicity is due to decreased water and feed intake.

  17. Development of quercetin-phospholipid complex to improve the bioavailability and protection effects against carbon tetrachloride-induced hepatotoxicity in SD rats.

    PubMed

    Zhang, Kexia; Zhang, Meiyu; Liu, Ziying; Zhang, Yuanyuan; Gu, Liqiang; Hu, Gaosheng; Chen, Xiaohui; Jia, Jingming

    2016-09-01

    Quercetin (QT) is a natural flavonoid with various biological activities and pharmacological actions. However, the bioavailability of QT is relatively low due to its low solubility which severely limits its use. In this study, we intended to improve the bioavailability of QT by preparing quercetin-phospholipid complex (QT-PC) and investigate the protective effect of QT-PC against carbon tetrachloride (CCl4) induced acute liver damage in Sprague-Dawley (SD) rats. The physicochemical properties of QT-PC were characterized in terms of infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD) and water/n-octanol solubility. FTIR, DSC and XRPD data confirmed the formation of QT-PC. The water solubility of QT was improved significantly in the prepared complex, indicating its increased hydrophilicity. Oral bioavailability of QT and QT-PC was evaluated in SD rats, and the plasma QT was estimated by HPLC-MS. QT-PC exhibited higher Cmax (1.58±0.11 vs. 0.67±0.08μg/mL), increased AUC0-∞ (8.60±1.25 vs. 2.41±0.51mg/Lh) and t1/2z (7.76±1.09 vs. 4.81±0.87h) when compared to free QT. The greater absorption of QT-PC group suggested the improved bioavailability. Moreover, biochemical changes and histopathological observations revealed that QT-PC provided better protection to rat liver than free QT at the same dose. Thus, phospholipid complexation might be one of the suitable approaches to improve the oral bioavailability of QT and obtain better protective effects against CCl4 induced acute liver damage in SD rats than free QT at the same dose level. PMID:27431774

  18. Hepatoprotective effects of phloridzin on hepatic fibrosis induced by carbon tetrachloride against oxidative stress-triggered damage and fibrosis in rats.

    PubMed

    Deng, Gaigai; Wang, Junzhi; Zhang, Qiaoyin; He, Haibo; Wu, Fangfang; Feng, Tianyan; Zhou, Jigang; Zou, Kun; Hattori, Masao

    2012-01-01

    The present study was to study the hepatoprotective effects of phloridzin (PHL) on hepatic fibrosis induced by carbon tetrachloride (CCl₄) in rats, on the basis of this investigation, the possible mechanism of PHL was elucidated. Male Sprague Dawley (SD) rats were randomly divided into six groups: control, model, PHL-L, PHL-M, PHL-H and colchine. All rats except control group were intraperitoneally injected with CCl₄, and control rats were injected with olive oil, twice a week for eight weeks. At the same time, the rats were orally given homologue drugs once a day, respectively. Hepatoprotective effects of PHL were evaluated by liver weight indexes, biochemical values, total antioxidant capacity and total-superoxide dismutase, histopathological observations, hepatic fibrosis, and the hepatic fibrosis relative gene and protein expressions. PHL significantly improved hepatic function; remarkably decreased serum hyaluronic acid (HA), transforming growth factor-β1 (TGF-β1), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and liver tissues hydroxyproline, malondialdehyde (MDA) levels, increased glutathione peroxidase (GSH-Px), total-antioxygen capacity (T-AOC) and total-superoxide dismutase (T-SOD) contents of liver tissues; Real-time polymerase chain reaction (PCR) and immunohisto-chemical results showed PHL might markedly reverse the up-regulated mRNA and protein expressions of the α-smooth muscle actin (SMA), TGF-β1 and tissue inhibitor of metalloproteinase-1 (TIMP1), up-regulate the matrix metalloproteinase-1 (MMP1) mRNA and protein expressions. Histopathological observations provided supportive evidence for biochemical analyses and the hepatic fibrosis relative gene and protein expressions, and with the dose of PHL increasing, the aforesaid improvement became more and more strong. The studies demonstrated that PHL exerted beneficially hepatoprotective effects on hepatic fibrosis induced by CCl₄, mainly enhancing antioxidant capacity of

  19. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources.

    PubMed

    de Blas, Maite; Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen; Navazo, Marino; Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley

    2016-08-15

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC-MSD for a one-year period (2007-2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003-2005, 2010-2011, and 2014-2015years). Median yearly CTC mixing ratios were slightly higher in the urban area (120pptv) than in VNP (80-100pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources. PMID:27092418

  20. Serum metabonomics study of the hepatoprotective effect of Corydalis saxicola Bunting on carbon tetrachloride-induced acute hepatotoxicity in rats by (1)H NMR analysis.

    PubMed

    Liang, Yong-Hong; Tang, Chao-Ling; Lu, Shi-Yin; Cheng, Bang; Wu, Fang; Chen, Zhao-Ni; Song, Fangming; Ruan, Jun-Xiang; Zhang, Hong-Ye; Song, Hui; Zheng, Hua; Su, Zhi-Heng

    2016-09-10

    Corydalis saxicola Bunting (CS), a traditional Chinese folk medicine, has been effectively used for treating liver disease in Zhuang nationality in South China. However, the exact hepatoprotective mechanism of CS was still looking forward to further elucidation by far. In present work, metabonomic study of biochemical changes in the serum of carbon tetrachloride (CCl4)-induced acute liver injury rats after CS treatment were performed using proton nuclear magnetic resonance ((1)H-NMR) analysis. Metabolic profiling by means of principal components analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation caused by CCl4 was reduced by CS treatment. A total of 9 metabolites including isoleucine (1), lactate (2), alanine (3), glutamine (4), acetone (5), succinate (6), phosphocholine (7), d-glucose (8) and glycerol (9) were considered as potential biomarkers involved in the development of CCl4-induced acute liver injury. According to pathway analysis by metabolites identified and correlation network construction by Pearson's correlation coefficency matrix, alanine, aspartate and glutamate metabolism and glycerolipid metabolism were recognized as the most influenced metabolic pathways associated with CCl4 injury. As a result, notably, deviations of metabolites 1, 3, 4, 7 and 9 in the process of CCl4-induced acute liver injury were improved by CS treatment, which suggested that CS mediated synergistically abnormalities of the metabolic pathways, composed of alanine, aspartate and glutamate metabolism and glycerolipid metabolism. In this study, it was the first report to investigate the hepatoprotective effect of the CS based on metabonomics strategy, which may be a potentially powerful tool to interpret the action mechanism of traditional Chinese folk medicines. PMID:27399344

  1. Dynamic Contrast-Enhanced Magnetic Resonance Imaging with Gd-EOB-DTPA for the Evaluation of Liver Fibrosis Induced by Carbon Tetrachloride in Rats

    PubMed Central

    Zhang, Wei; Kong, Xiang; Wang, Zhen J.; Luo, Song; Huang, Wei; Zhang, Long Jiang

    2015-01-01

    Purpose To investigate the utility of dynamic contrast-enhanced MRI (DCE-MRI) with Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) for detecting liver fibrosis induced by carbon tetrachloride (CCl4) in rats. Methods This study was approved by the institutional animal care and use committee. Liver fibrosis in rats was induced by intraperitoneal injection of 1 mL/kg 50% CCl4 twice a week for 4-13 weeks. Control rats were injected with saline. Liver fibrosis was graded using the Metaviar score: no fibrosis (F0), mild fibrosis (F1-F2) and advanced fibrosis (F3-F4). DCE-MRI with Gd-EOB-DTPA was performed for all rats. Ktrans, Kep, Ve and iAUC of the liver parenchyma were measured. Relative enhancement (RE) value of the liver was calculated on T1-weighted images at 15, 20 and 25 min after Gd-EOB-DTPA administration. Results Thirty-five rats were included: no fibrosis (n=13), mild fibrosis (n=11) and advanced fibrosis (n=11). Ktrans and iAUC values were highest in advanced fibrosis group and lowest in no fibrosis group (P<0.05). The area under the receiver operating characteristic curve (AUROC) for fibrosis (stages F1 and greater) were 0.773 and 0.882 for Ktrans and iAUC, respectively. AUROC for advanced fibrosis were 0.835 and 0.867 for Ktrans and iAUC, respectively. Kep and RE values were not able to differentiate fibrosis stages (all P>0.05). Conclusion Ktrans and iAUC obtained from DCE-MRI with Gd-EOB-DTPA are useful for the detection and staging of rat liver fibrosis induced by CCl4. PMID:26076199

  2. Protective effect of Öküzgözü (Vitis vinifera L. cv.) grape juice against carbon tetrachloride induced oxidative stress in rats.

    PubMed

    Pirinççioğlu, Mihdiye; Kızıl, Göksel; Kızıl, Murat; Özdemir, Gültekin; Kanay, Zeki; Ketani, M Aydın

    2012-06-01

    The consumption of fruits plays an important role as a health protecting factor. Grapes (Vitis vinifera L.) are believed to have health benefits due to their antioxidant activity. Öküzgözü is the largest among the grape varieties grown in Turkey. Carbon tetrachloride (CCl₄) causes free radical generation in many tissues such as the liver, kidney, heart, lung, testis, brain and blood. Ursodeoxycholic acid (UDCA) is the only drug to treat primary biliary cirrhosis, but the effects remain controversial. The aim of the present study is to investigate the protective effect of Öküzgözü grape juice or UDCA against tissue damage induced by CCl₄ in rats. The amount of total phenolics and flavonoids were found to be 1208.00 +/- 43.00 μg ml⁻¹ as the gallic acid equivalent and 5.2 +/- 0.19 μg ml⁻¹ as the quercitin equivalent in Öküzgözü grape juice, respectively. In vivo administration of CCl₄ caused a significant increase of various biochemical parameters such as alanine amino transferase (ALT), aspartate amino transferase (AST), total bilirubin (TB) and a decrease in albumin (ALB) levels in serum or an increase in malondialdehyde (MDA) levels in the tissues when compared to a control. Administration of CCl₄ along with Öküzgözü grape juice or ursodeoxycolic acid (UDCA) significantly reduces these changes. Histopathalogical studies also support the protective effect of the extract. This study demonstrates the protective activity of Öküzgözü grape juice and thus scientifically supports the usage of this fruit in various traditional medicines for the treatment of tissue disorders. The effect of Öküzgözü grape juice was comparable with that of UDCA.

  3. Characterization of Carbon Onion Nanomaterials for Environmental Remediation

    EPA Science Inventory

    The unique properties of carbonaceous nanomaterials, including small particle size, high surface area, and manipulatable surface chemistry, provide high potential for their application to environmental remediation. While research has devoted to develop nanotechnology for environm...

  4. Activated carbon adsorption of PAHs from vegetable oil used in soil remediation.

    PubMed

    Gong, Zongqiang; Alef, Kassem; Wilke, Berndt-Michael; Li, Peijun

    2007-05-01

    Vegetable oil has been proven to be advantageous as a non-toxic, cost-effective and biodegradable solvent to extract polycyclic aromatic hydrocarbons (PAHs) from contaminated soils for remediation purposes. The resulting vegetable oil contained PAHs and therefore required a method for subsequent removal of extracted PAHs and reuse of the oil in remediation processes. In this paper, activated carbon adsorption of PAHs from vegetable oil used in soil remediation was assessed to ascertain PAH contaminated oil regeneration. Vegetable oils, originating from lab scale remediation, with different PAH concentrations were examined to study the adsorption of PAHs on activated carbon. Batch adsorption tests were performed by shaking oil-activated carbon mixtures in flasks. Equilibrium data were fitted with the Langmuir and Freundlich isothermal models. Studies were also carried out using columns packed with activated carbon. In addition, the effects of initial PAH concentration and activated carbon dosage on sorption capacities were investigated. Results clearly revealed the effectiveness of using activated carbon as an adsorbent to remove PAHs from the vegetable oil. Adsorption equilibrium of PAHs on activated carbon from the vegetable oil was successfully evaluated by the Langmuir and Freundlich isotherms. The initial PAH concentrations and carbon dosage affected adsorption significantly. The results indicate that the reuse of vegetable oil was feasible.

  5. THE USE OF VAPOR EXTRACTION SYSTEM AND ITS SUBSEQUENT REDUCTION OF WORKER EXPOSURE TO CARBON TETRACHLORIDE DURING RETRIEVAL OF HANFORDS LEGACY WASTE

    SciTech Connect

    PITTS DA

    2008-03-18

    The Hanford Site is a decommissioned nuclear productions complex located in south eastern Washington and is operated by the Department of Energy (DOE). From 1955 to 1973, carbon tetrachloride (CCl{sub 4}), used in mixtures with other organic compounds, was used to recover plutonium from aqueous streams at Z Plant located on the Hanford Site. The aqueous and organic liquid waste that remained at the end of this process was discharged to soil columns in waste cribs located near Z Plant. Included in this waste slurry along with CCl{sub 4} were tributyl phosphate, dibutyl butyl phosphate, and lard oil. (Truex et al., 2001). In the mid 1980's, CCl{sub 4} was found in the unconfined aquifer below the 200 West Area and subsequent ground water monitoring indicated that the plume was widespread and that the concentrations were increasing. It has been estimated that approximately 750,000 kg (826.7 tons) of CCl{sub 4} was discharged to the soil from 1955 to 1973. (Truex et al., 2001). With initial concentration readings of approximately 30,000 parts per million by volume (ppmv) in one well field alone, soil vapor extraction began in 1992 in an effort to remove the CCl{sub 4} from the soil. (Rohay, 1999). Since 1992, approximately 78,607.6 kg (86.65 tons) of CCl{sub 4} have been extracted from the soil through the process of soil vapor extraction and 9,409.8 kg (10.37 tons) have been removed from the groundwater. (EPA, 2006). The success of this environmental cleanup process benefited not only the environment but also workers who were later involved in the retrieval of solid waste from trenches that were in or near the CCl{sub 4} plume. Solid waste was buried in trenches near Z Plant from 1967 to 1990. The solid waste, some of which was chemically and/or radioactively contaminated, was buried in trenches in steel or fiber drums, fiberboard boxes, fiberglass-reinforced plywood boxes, and steel, concrete, or wooden boxes. Much of this waste was buried with the intention of

  6. Endogenous hydrogen sulfide is associated with angiotensin II type 1 receptor in a rat model of carbon tetrachloride-induced hepatic fibrosis

    PubMed Central

    FAN, HUI-NING; CHEN, NI-WEI; SHEN, WEI-LIN; ZHAO, XIANG-YUN; ZHANG, JING

    2015-01-01

    The present study aimed to investigate the effects of endogenous hydrogen sulfide (H2S) on the expression levels of angiotensin II type 1 receptor (AGTR1) in a rat model of carbon tetrachloride (CCl4)-induced hepatic fibrosis. A total of 56 Wistar rats were randomly divided into four groups: Normal control group, model group, sodium hydrosulfide (NaHS) group, and DL-propargylglycine (PAG) group. Hepatic fibrosis was induced by CCl4. The rats in the PAG group were intraperitoneally injected with PAG, an inhibitor of cystathionine-γ-lyase (CSE). The rats in the NaHS group were intraperitoneally injected with NaHS. An equal volume of saline solution was intraperitoneally injected into both the control and model groups. All rats were sacrificed at week three or four following treatment. The serum levels of hyaluronidase (HA), laminin protein (LN), procollagen III (PcIII), and collagen IV (cIV) were detected using ELISA. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and albumin (ALB) were detected using an automatic biochemical analyzer. The liver mRNA expression levels of CSE were detected by reverse transcription-quantitative polymerase chain reaction. The liver expression levels of AGTR1 and the plasma expression levels of H2S were detected using western blot analyses. The results indicated that the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly higher in the PAG group, as compared with the model group (P<0.05). Conversely, the expression levels of ALB were significantly lower in the PAG group, as compared with the model group. In addition, the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly lower in the NaHS group, as compared with

  7. Comparative study of the pharmacokinetics of carbon tetrachloride in the rat following repeated inhalation exposures of 8 and 11. 5 hr/day

    SciTech Connect

    Paustenbach, D.J.; Carlson, G.P.; Christian, J.E.; Born, G.S.

    1986-04-01

    To evaluate whether exposure to inhaled vapors for periods longer than 8 hr/day could affect the rates and routes of elimination, male Sprague-Dawley rats were repeatedly exposed to 100 ppm of radiolabeled carbon tetrachloride (/sup 14/CCl/sub 4/) in a closed-loop chamber. One group was exposed for 8 hr/day for 5 days and another group for 11.5 hr/day for 4 days. Two other groups were exposed for either 8 hr/day for 10 of 12 consecutive days or 11.5 hr/day for 7 of 10 days. The elimination of /sup 14/C activity was measured in the expired air, urine, and feces for up to 100 hr following exposure and the pharmacokinetic parameters were determined. Following 2 weeks of exposure to the 8-hr/day schedule, /sup 14/CCl/sub 4/ in the breath and /sup 14/C activity in the feces comprised 45 and 48% of the total /sup 14/C excreted, respectively. Following 2 weeks of exposure to the 11.5-hr/day schedule, the values were 32 and 62%, respectively, indicating that repeated exposure to the longer schedule altered the route of elimination of CCl/sub 4/. Regardless of the period of exposure, less than 8% of the inhaled /sup 14/CCl/sub 4/ was excreted in the urine and less than 2% was exhaled in the breath as the /sup 14/CO/sub 2/ metabolite. Approximately 97-98% of the /sup 14/C activity in the expired air was /sup 14/CCl/sub 4/. The quantities of /sup 14/C noted in the feces and urine suggest that more than 60% of the inhaled CCl/sub 4/ was metabolized. Elimination of /sup 14/CCl/sub 4/ and /sup 14/CO/sub 2/ in the breath followed a two-compartment, first-order pharmacokinetic model (r2 = 0.98). For rats exposed 8 hr/day and 11.5 hr/day for 2 weeks, the average half-lives for elimination of /sup 14/CCl/sub 4/ in the breath for the fast (alpha) and slow (beta) phases averaged 96 and 455 min, and 89 and 568 min, respectively. The average alpha and beta half-lives for elimination of /sup 14/CO/sub 2/ in the breath

  8. Kupffer cell stimulation with Corynebacterium parvum reduces some cytochrome P450-dependent activities and diminishes acetaminophen and carbon tetrachloride-induced liver injury in the rat.

    PubMed

    Raiford, D S; Thigpen, M C

    1994-11-01

    Chemical activation of Kupffer cells in vivo by vitamin A or latex beads is associated with a worsening of hepatic injury induced by the P450-dependent hepatotoxins acetaminophen (ACET) and carbon tetrachloride (CCl4) and by the P450-independent toxin galactosamine (GLN). Immunostimulants such as Corynebacterium parvum (CP) also activate Kupffer cells, but do so while prompting release of soluble mediators which depress microsomal oxidative activities in cultured hepatocytes. Therefore, we sought to characterize the effects of CP on hepatic injury in vivo due to ACET and CCl4 while employing GLN as a control. Hepatic microsomal oxidative activity and glutathione (GSH) disposition were examined since each influences susceptibility to injury from ACET or CCl4. Rats were given CP 28 mg/kg i.v. 5 days before challenge with hepatotoxicant. Hepatic injury was assessed 24 hr after hepatotoxicant administration by measurement of serum alanine aminotransferase (ALT) activity and review of histological sections. Livers from parallel groups of rats were used to prepare microsomal and cytosolic fractions, to measure tissue GSH, or for perfusion to assess GSH efflux. Significant reductions in injury due to ACET or CCl4 were observed while injury due to GLN was potentiated. Serum ALT levels after ACET were 3000 +/- 620 in controls vs 170 +/- 45 IU/liter in the CP-treated group and ALT levels after CCl4 were 3100 +/- 500 in controls vs 1700 + 450 IU/liter in the CP-treated group. In contrast, serum ALT levels after GLN were 920 +/- 230 in controls vs 1700 +/- 370 in the CP-treated group. Patterns of hepatic injury observed on histological sections were those characteristic for each toxin and the severity of injury correlated well with alterations in serum ALT levels for each agent. Hepatic microsomal fractions from rats pretreated with CP showed significantly diminished total cytochrome P450 content as well as reduced activity for two P450IIE1 substrates, p-nitrophenol and 7

  9. Thermal decomposition of carbon tetrachloride

    SciTech Connect

    Michael, J.V.; Lim, K.P. ); Kumaran, S.S.; Kiefer, J.H. )

    1993-03-04

    The first rate measurements of the thermal dissociation of CCl[sub 4] are reported. Three detection techniques were used in monitoring the reaction rate for various dilutions over a wide temperature range: (i) ARAS of product Cl atoms in reflected shock waves using 3.2--6.4 ppM of CCl[sub 4] in Ar over 1084--1705 K and 150--908 Torr, (ii) decay of CCl[sub 4] by molecular absorption of O-atom resonance radiation in reflected shock waves using 48--173 ppM of CCl[sub 4] in Ar over 1192--1733 K and 219--855 Torr, and (iii) laser schlieren density gradients in incident shock waves using 0.5 and 2% CCl[sub 4] in Kr over 1470--2186 K and 90--660 Torr. The second-order rates from ARAS and molecular absorption measurements for the bond fission reaction CCl[sub 4] [yields] CCl[sub 3] + Cl are in complete agreement with the laser schlieren results where they overlap. The temperature and pressure dependence of these rates is well characterized by Gorin model RRKM calculations using current [Delta]H[degrees][sub 0] = 67.71 kcal/mol for E[sub 0], derived from [Delta][sub f]H[degrees][sub 298] = 17.0 kcal/mol for for CCl[sub 3]. The low-pressure rate constant (k[sub 0]) derived from this RRKM fit is log k[sub 0] (cm[sup 3]/(mol s)) = 54.980 [minus] 10.624 log T [minus] 74.796 (kcal/mol)/2.303RT. These low-pressure rates require unusually large [beta][sub c] corresponding to a [l angle][Delta]E[r angle][sub down] = 1200 cm[sup [minus]1]. This may be a general feature of chlorocarbon dissociations. The ARAS data indicate that two Cl atoms are ultimately produced for each CCl[sub 4] that dissociates, with the second Cl atom forming slower than the first. Here all the measurements are consistent with a further dissociation of CCl[sub 3], CCl[sub 3] [yields] CCl[sub 2] + Cl, as the dominant source of secondary Cl-atom at a rate about 0.1 that of the primary fission. 31 refs., 9 figs., 2 tabs.

  10. Investigations into Wetland Carbon Sequestration as Remediation for Global Warming

    SciTech Connect

    Thom, Ronald M.; Blanton, Susan L.; Borde, Amy B.; Williams, Greg D.; Woodruff, Dana L.; Huesemann, Michael H.; KW Nehring and SE Brauning

    2002-01-01

    Wetlands can potentially sequester vast amounts of carbon. However, over 50% of wetlands globally have been degraded or lost. Restoration of wetland systems may therefore result in increased sequestration of carbon. Preliminary results of our investigations into atmospheric carbon sequestration by restored coastal wetlands indicate that carbon can be sequestered in substantial quantities in the first 2-50 years after restoration of natural hydrology and sediment accretion processes.

  11. Environmental remediation and conversion of carbon dioxide (CO(2)) into useful green products by accelerated carbonation technology.

    PubMed

    Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk

    2010-01-01

    This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO(2)), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called 'accelerated carbonation', which completes its fast reaction within few hours by using pure CO(2). Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO(2) in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO(2) emissions and environmental remediation. PMID:20195442

  12. Environmental remediation and conversion of carbon dioxide (CO(2)) into useful green products by accelerated carbonation technology.

    PubMed

    Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk

    2010-01-01

    This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO(2)), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called 'accelerated carbonation', which completes its fast reaction within few hours by using pure CO(2). Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO(2) in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO(2) emissions and environmental remediation.

  13. DESCRIPTION OF MODELING ANALYSES IN SUPPORT OF THE 200-ZP-1 REMEDIAL DESIGN/REMEDIAL ACTION

    SciTech Connect

    VONGARGEN BH

    2009-11-03

    The Feasibility Study/or the 200-ZP-1 Groundwater Operable Unit (DOE/RL-2007-28) and the Proposed Plan/or Remediation of the 200-ZP-1 Groundwater Operable Unit (DOE/RL-2007-33) describe the use of groundwater pump-and-treat technology for the 200-ZP-1 Groundwater Operable Unit (OU) as part of an expanded groundwater remedy. During fiscal year 2008 (FY08), a groundwater flow and contaminant transport (flow and transport) model was developed to support remedy design decisions at the 200-ZP-1 OU. This model was developed because the size and influence of the proposed 200-ZP-1 groundwater pump-and-treat remedy will have a larger areal extent than the current interim remedy, and modeling is required to provide estimates of influent concentrations and contaminant mass removal rates to support the design of the aboveground treatment train. The 200 West Area Pre-Conceptual Design/or Final Extraction/Injection Well Network: Modeling Analyses (DOE/RL-2008-56) documents the development of the first version of the MODFLOW/MT3DMS model of the Hanford Site's Central Plateau, as well as the initial application of that model to simulate a potential well field for the 200-ZP-1 remedy (considering only the contaminants carbon tetrachloride and technetium-99). This document focuses on the use of the flow and transport model to identify suitable extraction and injection well locations as part of the 200 West Area 200-ZP-1 Pump-and-Treat Remedial Design/Remedial Action Work Plan (DOEIRL-2008-78). Currently, the model has been developed to the extent necessary to provide approximate results and to lay a foundation for the design basis concentrations that are required in support of the remedial design/remediation action (RD/RA) work plan. The discussion in this document includes the following: (1) Assignment of flow and transport parameters for the model; (2) Definition of initial conditions for the transport model for each simulated contaminant of concern (COC) (i.e., carbon

  14. Environmental Remediation and Conversion of Carbon Dioxide (CO2) into Useful Green Products by Accelerated Carbonation Technology

    PubMed Central

    Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk

    2010-01-01

    This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO2), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called ‘accelerated carbonation’, which completes its fast reaction within few hours by using pure CO2. Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO2 in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO2 emissions and environmental remediation. PMID:20195442

  15. Behavior of solid carbon sources for biological denitrification in groundwater remediation.

    PubMed

    Zhang, Jianmei; Feng, Chuanping; Hong, Siqi; Hao, Huiling; Yang, Yingnan

    2012-01-01

    The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO(3)(-)-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO(3)(-)-N.L(-1).d(-1).g(-1), respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.

  16. Microwave thermal remediation of crude oil contaminated soil enhanced by carbon fiber.

    PubMed

    Li, Dawei; Zhang, Yaobin; Quan, Xie; Zhao, Yazhi

    2009-01-01

    Thermal remediation of the soil contaminated with crude oil using microwave heating enhanced by carbon fiber (CF) was explored. The contaminated soil was treated with 2.45 GHz microwave, and CF was added to improve the conversion of microwave energy into thermal energy to heat the soil. During microwave heating, the oil contaminant was removed from the soil matrix and recovered by a condensation system of ice-salt bath. The experimental results indicated that CF could efficiently enhance the microwave heating of soil even with relatively low-dose. With 0.1 wt.% CF, the soil could be heated to approximately 700 degrees C within 4 min using 800 W of microwave irradiation. Correspondingly, the contaminated soil could be highly cleaned up in a short time. Investigation of oil recovery showed that, during the remediation process, oil contaminant in the soil could be efficiently recovered without causing significant secondary pollution.

  17. [Microwave thermal remediation of soil contaminated with crude oil enhanced by granular activated carbon].

    PubMed

    Li, Da-Wei; Zhang, Yao-Bin; Quan, Xie; Zhao, Ya-Zhi

    2009-02-15

    The advantage of rapid, selective and simultaneous heating of microwave heating technology was taken to remediate the crude oil-contaminated soil rapidly and to recover the oil contaminant efficiently. The contaminated soil was processed in the microwave field with addition of granular activated carbon (GAC), which was used as strong microwave absorber to enhance microwave heating of the soil mixture to remove the oil contaminant and recover it by a condensation system. The influences of some process parameters on the removal of the oil contaminant and the oil recovery in the remediation process were investigated. The results revealed that, under the condition of 10.0% GAC, 800 W microwave power, 0.08 MPa absolute pressure and 150 mL x min(-1) carrier gas (N2) flow-rate, more than 99% oil removal could be obtained within 15 min using this microwave thermal remediation enhanced by GAC; at the same time, about 91% of the oil contaminant could be recovered without significant changes in chemical composition. In addition, the experiment results showed that GAC can be reused in enhancing microwave heating of soil without changing its enhancement efficiency obviously.

  18. Aqueous extract of Gracilaria tenuistipitata suppresses LPS-induced NF-κB and MAPK activation in RAW 264.7 and rat peritoneal macrophages and exerts hepatoprotective effects on carbon tetrachloride-treated rat.

    PubMed

    Tseng, Chin-Kai; Lin, Chun-Kuang; Chang, Hsueh-Wei; Wu, Yu-Hsuan; Yen, Feng-Lin; Chang, Fang-Rong; Chen, Wei-Chun; Yeh, Chi-Chen; Lee, Jin-Ching

    2014-01-01

    In addition to the previous investigations of bioactivity of aqueous extract of the edible Gracilaria tenuistipitata (AEGT) against H2O2-induced DNA damage and hepatitis C virus replication, the purpose of this study is to evaluate the potential therapeutic properties of AEGT against inflammation and hepatotoxicity using lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 cells, primary rat peritoneal macrophages and carbon tetrachloride (CCl4)-induced acute hepatitis model in rats. AEGT concentration-dependently inhibited the elevated RNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2, thereby reducing nitric oxide and prostaglandin E2 levels, respectively. Moreover, AEGT significantly suppressed the production of LPS-induced proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. These inhibitory effects were associated with the suppression of nuclear factor-kappa B activation and mitogen-activated protein kinase phosphorylation by AEGT in LPS-stimulated cells. In addition, we highlighted the hepatoprotective and curative effects of AEGT in a rat model of CCl4-intoxicated acute liver injury, which was evident from reduction in the elevated serum aspartate aminotransferase and alanine aminotransferase levels as well as amelioration of histological damage by pre-treatment or post-treatment of AEGT. In conclusion, the results demonstrate that AEGT may serve as a potential supplement in the prevention or amelioration of inflammatory diseases.

  19. The Potential Protective Effect of Physalis peruviana L. against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Is Mediated by Suppression of Oxidative Stress and Downregulation of MMP-9 Expression

    PubMed Central

    Al-Olayan, Ebtisam M.; El-Khadragy, Manal F.; Aref, Ahmed M.; Othman, Mohamed S.; Kassab, Rami B.; Abdel Moneim, Ahmed E.

    2014-01-01

    The active constituent profile in Cape gooseberry (Physalis peruviana L.) juice was determined by GC-MS. Quercetin and kaempferol were active components in the juice. In this study we have evaluated its potential protective effect on hepatic injury and fibrosis induced by carbon tetrachloride (CCl4). Twenty-eight rats divided into 4 groups: Group I served as control group, and Group II received weekly i.p. injection of 2 mL CCl4/kg bwt for 12 weeks. Group III were supplemented with Physalis juice via the drinking water. The animals of Group IV received Physalis juice as Group III and also were intraperitoneally injected weekly with 2 mL CCl4/kg bwt for 12 weeks. Hepatoprotective effect was evaluated by improvement in liver enzymes serum levels, reduction in collagen areas, downregulation in expression of the fibrotic marker MMP-9, reduction in the peroxidative marker malonaldehyde and the inflammatory marker nitric oxide, and restoration of the activity of antioxidant enzymatic and nonenzymatic systems, namely, glutathione content, superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, and glutathione reductase activities. The results show that the potential hepatoprotective effects of Physalis peruviana may be due to physalis acts by promotion of processes that restore hepatolobular architecture and through the inhibition of oxidative stress pathway. PMID:24876910

  20. Remediation of Nitrate-contaminated Groundwater by a Mixture of Iron and Activated Carbon

    NASA Astrophysics Data System (ADS)

    Huang, Guoxin; Liu, Fei; Jin, Aifang; Qin, Xiaopeng

    2010-11-01

    Nitrate contamination in groundwater has become a major environmental and health problem worldwide. The aim of the present study is to remediate groundwater contaminated by nitrate and develop potential reactive materials to be used in PRBs (Permeable Reactive Barriers). A new approach was proposed for abiotic groundwater remediation by reactive materials of iron chips and granular activated carbon particles. Batch tests were conducted and remediation mechanisms were discussed. The results show that nitrate decreases from 86.31 to 33.79 mgṡL-1 under the conditions of near neutral pH and reaction time of 1h. The combination of iron chips and activated carbon particles is cost-effective and suitable for further use as denitrification media in PRBs. Nitrogen species don't change significantly with the further increase in reaction time (>1 h). The iron-activated carbon-water-nitrate system tends to be steady-state. Small amounts of ammonium and nitrite (0.033-0.039 and 0.14-3.54 mgṡL-1, respectively) appear at reaction time from 0 h to 5 h. There is no substantial accumulation of nitrogen products in the system. The removal rate of nitrate only reaches 16.11% by sole iron chips at reaction time of 5 h, while 63.57% by the mixture of iron chips and activated carbon particles. There is significantly synergistic and promotive effect of mixing the two different types of materials on nitrate treatment. Fe/C ratio (1/1.5-1/2.5) doesn't cause dramatically different residual nitrate concentrations (24.09-26.70 mgṡL-1). Nitrate can't be limitlessly decreased with decreasing Fe/C ratio. The concomitant occurrences of chemical reduction, galvanic cell reaction, electrophoretic accumulation, chemical coagulation, and physical adsorption are all responsible for the overall nitrate removal by iron allied with activated carbon. To accurately quantify various nitrogen species, further studies on adsorption mechanisms of nitrite and nitrate are needed.

  1. METHOD FOR PRODUCING THORIUM TETRACHLORIDE

    DOEpatents

    Mason, E.A.; Cobb, C.M.

    1960-03-15

    A process for producing thorium tetrachloride from thorium concentrate comprises reacting thorium concentrates with a carbonaceous reducing agent in excess of 0.05 part by weight per part of thoriferous concentrate at a temperature in excess of 1300 deg C, cooling and comminuting the mass, chlorinating the resulting comminuting mass by suspending in a gaseous chlorinating agent in a fluidized reactor at a temperatare maintained between about l85 deg C and 770 deg C, and removing the resulting solid ThCl/sub 4/ from the reaction zone.

  2. Enhanced electrokinetic (E/K) remediation on copper contaminated soil by CFW (carbonized foods waste).

    PubMed

    Han, Jung-Geun; Hong, Ki-Kwon; Kim, Young-Woong; Lee, Jong-Young

    2010-05-15

    The E/K remediation method is presented to purify low permeable contaminated soils due to Cu(2+), and carbonized foods waste (CFW) was used as a permeable reactive barrier (PRB) material. For adsorption and precipitation of the Cu(2+) in the PRB during its motion, PRB was installed in a zone of rapidly changing pH values. The adsorption efficiency of CFW used as PRB material was found to be 4-8 times more efficient than that of Zeolite. Throughout the experiment, a voltage slope of 1V/cm was implemented and acetic acid was injected on the anode to increase the remediation efficiency. The electrode exchange was executed to more completely remove precipitated heavy metals in the vicinity of the cathode. The majority of Cu(2+) was adsorbed or sedimented by CFW prior to the exchange of the electrode, and the remaining quantity of precipitated Cu(2+) on the cathode had decreased with an increase in the operating time. Experiments of seven cases with different E/K operating times were performed, and the average removal ratios were 53.4-84.6%. The removal efficiencies for the majority of cases increased proportionally with an increase in the operating time. After the experiments were completed, the adsorbed Cu(2+) on CFW was 75-150 mg. This means that the role of CFW as the material in PRB for remediating heavy metals was confirmed. The cost of energies needed to remove Cu(2+), CFW, and acetic acid are estimated at US$ 13.3-40/m(3). PMID:20080337

  3. Corticosterone mediates the inhibitory effect of restraint stress on the migration of mesenchymal stem cell to carbon tetrachloride-induced fibrotic liver by downregulating CXCR4/7 expression.

    PubMed

    Zhang, Shanshan; Lv, Chuan; Yang, Xue; Han, Zhipeng; Zhang, Shuili; Zhang, Jianwei; Zong, Chen; Gao, Lu; Li, Li; Zhao, Qiudong; Li, Rong; Yang, Yang; Yu, Fenghai; Li, Xiaoning; Zhang, Ping; Wei, Lixin

    2015-03-01

    Recent studies have revealed that mesenchymal stem cells (MSCs) have a great potential in therapeutic applications. The low efficiency of MSC recruitment and homing to sites of diseased organ tissue, however, remains a major hurdle in their application for treatment of diseases. Stress is commonly associated with various diseases. At the present time, little information is available about the effect of stress on MSC function. Here, we employed a carbon tetrachloride (CCl4)-induced mouse liver fibrosis model to investigate whether constraint stress affects the migration of MSCs to fibrotic liver. MSC homing to the fibrotic liver was significantly inhibited in mice with restraint stress. Restraint stress induced an elevation of corticosterone level in the serum. Blocking glucocorticoid signaling with either corticosterone-synthesis inhibitor metyrapone (MET) or glucocorticoid receptor antagonist RU486 attenuated restraint stress-induced inhibition of MSCs migration. The serum concentration of stromal cell-derived factor-1 (SDF-1) increased in mice treated with CCl4. Restraint stress had no influence on expression of SDF-1 and hepatocyte growth factor (HGF) in the fibrotic liver. Culture with the serum of CCl4-treated mice or SDF-1 promoted MSC migration, which was suppressed by corticosterone. Exposure of MSCs to corticosterone decreased their expression of C-X-C chemokine receptor type 4 (CXCR4) and C-X-C chemokine receptor type 7 (CXCR7). These results demonstrate that the inhibitory effect of corticosterone on MSC migration might be mediated via decreasing the expression of CXCR4 and CXCR7 in MSCs. Interventions targeting the interaction between corticosterone and its receptor improve migration and homing of MSCs in hosts receiving transplantation of these cells. PMID:25268050

  4. Comprehensive characterization of serum clinical chemistry parameters and the identification of urinary superoxide dismutase in a carbon tetrachloride-induced model of hepatic fibrosis in the female Hanover Wistar rat.

    PubMed

    Smyth, Rosemary; Munday, Michael R; York, Malcolm J; Clarke, Christopher J; Dare, Theo; Turton, John A

    2007-10-01

    Carbon tetrachloride (CCl(4)) was used to induce liver fibrosis in the rat. Using this model, we have identified changes in serum and urinary clinical chemistry parameters, and characterized histopathological lesions in the liver. Two experiments were conducted. In Experiment 1, rats were dosed at six levels of CCl(4) (0.06-0.36 ml/kg) twice weekly for 6 weeks, followed by a 6-week non-dosing recovery period (week 12). Livers were removed for histology at 6 and 12 weeks and serum parameters analysed. In Experiment 2, rats were given seven dose levels of CCl(4) (0.4-1.0 ml/kg) twice weekly for 6 weeks, followed by a 6-week recovery period (week 12); urine samples were analysed at 3, 6, 9 and 12 weeks using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Liver fibrosis was evident at 6 weeks in Experiments 1 and 2, and the activity of serum enzymes (including alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase) was increased. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis (Experiment 2) revealed a protein band at 18.4 kDa in urine from rats treated with CCl(4), not present in control urine, which was identified as copper/zinc superoxide dismutase (Cu/Zn SOD). Western blotting revealed that SOD was increased in urine from rats treated with CCl(4) at 3 and 6 weeks, but not at 9 and 12 weeks. We conclude that Cu/Zn SOD is a urinary marker of hepatic necrosis, but not hepatic fibrosis.

  5. Induction of Nrf2-dependent Antioxidation and Protection Against Carbon Tetrachloride-induced Liver Damage by Andrographis Herba (穿心蓮chuān xīn lián) Ethanolic Extract

    PubMed Central

    Chen, Haw-Wen; Huang, Yu-Ju; Yao, Hsien-Tsung; Lii, Chong-Kuei

    2012-01-01

    Andrographis paniculata is a traditional Chinese herb and displays diverse biological activities including antioxidation, anti-tumorigenesis, anti-virus, and anti-atherogenesis. In this study, we investigated the up-regulation of ethanolic extract of A. paniculata (APE) on the antioxidant defense in rat livers and whether this enhancement protected against carbon tetrachloride (CCl4)-induced liver damage. Male Sprague-Dawley rats were orally administered (i.g.) 0, 0.75, or 2 g/kg/d APE for 5 d. At d 6, rats were sacrificed and liver tissues were removed. Some animals (n=8) were intraperitoneally injected CCl4 (1 mL/kg, 50% in olive oil) and blood was drawn 24 h after CCl4 treatment. The results showed that APE increased hepatic glutathione (GSH) content and superoxide dismutase, GSH peroxidase, and GSH S-transferase activities in a dose-dependent manner (p < 0.05). Results of immunoblotting and RT-PCR revealed that rats treated with APE had higher glutamate cysteine ligase catalytic and modifier subunits, heme oxygenase 1, superoxide dismutase 1, and GSH S-transferase Ya and Yb protein and mRNA expression than those of control rats. Moreover, APE increased Nrf2 nuclear translocation and Nrf2 binding to DNA in rat liver. In the presence of CCl4, APE decreased hepatic thiobarbituric acid-reactive substances production and plasma aspartate aminotransferase and alanine aminotransferase activities. These results suggest that APE protection against CCl4 insult is attributed, at least in part, to its up-regulation of antioxidant defense in rat liver. PMID:24716135

  6. A mixed quantum-classical molecular dynamics study of the hydroxyl stretch in methanol/carbon tetrachloride mixtures III: nonequilibrium hydrogen-bond dynamics and infrared pump-probe spectra.

    PubMed

    Kwac, Kijeong; Geva, Eitan

    2013-06-27

    We present a mixed quantum-classical molecular dynamics study of the nonequilibrium hydrogen-bond dynamics following vibrational energy relaxation of the hydroxyl stretch in a 10 mol % methanol/carbon tetrachloride mixture and pure methanol. The ground and first-excited energy levels and wave functions are identified with the eigenvalues and eigenfunctions of the hydroxyl's adiabatic Hamiltonian and as such depend parametrically on the configuration of the remaining, classically treated, degrees of freedom. The dynamics of the classical degrees of freedom are in turn governed by forces obtained by taking the expectation value of the force with respect to the ground or excited vibrational wave functions. Polarizable force fields and nonlinear mapping relations between the hydroxyl transition frequencies and dipole moments and the electric field along the hydroxyl bond are used, which were previously shown to quantitatively reproduce the experimental infrared steady-state absorption spectra and excited state lifetime [Kwac, K.; Geva, E. J. Phys. Chem. B 2011, 115, 9184; 2012, 116, 2856]. The relaxation from the first-excited state to the ground state is treated as a nonadiabatic transition. Within the mixed quantum-classical treatment, relaxation from the excited state to the ground state is accompanied by a momentum-jump in the classical degrees of freedom, which is in turn dictated by the nonadiabatic coupling vector. We find that the momentum jump leads to breaking of hydrogen bonds involving the relaxing hydroxyl, thereby blue-shifting the transition frequency by more than the Stokes shift between the steady-state emission and absorption spectra. The subsequent nonequilibrium relaxation toward equilibrium on the ground state potential energy surface is thereby accompanied by red shifting of the transition frequency. The signature of this nonequilibrium relaxation process on the pump-probe spectrum is analyzed in detail. The calculated pump-probe spectrum is found

  7. Protective effects of Lycium barbarum polysaccharides against carbon tetrachloride-induced hepatotoxicity in precision-cut liver slices in vitro and in vivo in common carp (Cyprinus carpio L.).

    PubMed

    Liu, Yingjuan; Cao, Liping; Du, Jinliang; Jia, Rui; Wang, Jiahao; Xu, Pao; Yin, Guojun

    2015-03-01

    The protective effects of Lycium barbarum polysaccharides (LBPs) against carbon tetrachloride-induced hepatotoxicity in common carp were investigated in vitro and in vivo. Precision-cut liver slices (PCLSs) were employed as an in vitro model system. LBPs (0.1, 0.3 and 0.6 mg/ml) was added to PCLSs culture system before (pre-treatment), after (post-treatment) and both before and after (pre- and post-treatment) the exposure of PCLSs to 12 mM CCl4. The supernatants and PCLSs were collected for biochemical analyses. Results showed that LBPs inhibited the elevations of the marker enzymes (GOT, GPT, LDH and AKP) and MDA induced by CCl4 in all LBPs treatments and it also enhanced the suppressed antioxidant enzymes (SOD, CAT, GSH-Px, GST) and GSH, in the pre-treatment and pre- and post-treatment. In vivo, fish were fed diets containing LBPs at 0.1, 0.5 and 1% for 60 d before an intraperitoneal injection of 30% CCl4 in olive oil at a volume of 0.05 ml/10 g body weight. At 72 h post-injection, blood and liver samples were taken for biochemical analyses. Results showed that LBPs at 0.5 and 1% significantly reduced the levels of GOT, GPT and LDH in the serum; the decreases of the antioxidant enzymes and the increase of MDA in the liver tissue were inhibited markedly. Moreover, LBPs even at lower concentration exerted a potent DPPH scavenging activity. Overall results prove the hepatoprotective and antioxidant effects of LBPs and support the use of LBPs as a hepatoprotective agent in fish.

  8. Changes in soil organic carbon fractions after remediation of a coastal floodplain soil.

    PubMed

    Wong, V N L; McNaughton, C; Pearson, A

    2016-03-01

    Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise to form coastal acid sulfate soils (CASS) and contain high concentrations of acidity and trace metals. CASS are found on every continent globally except Antarctica. When sulfidic sediments are oxidised, scalds can form, which are large bare patches without vegetation. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a CASS scald. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m (426 Mg C/ha, 478 Mg C/ha and 473 Mg C/ha at sites C, LO and LM, respectively). The particulate organic C (POC) fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Reformation of acid volatile sulfide (AVS) occurred throughout the profile at site LM, whereas only limited AVS reformation occurred at sites LO and C. Higher AVS at site LM may be linked to the additional source of organic matter provided by the mulch. POC can also potentially contribute to decreasing acidity as a labile SOC source for Fe(3+) and SO4(2-) reduction. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production. These results highlight the importance of maintaining vegetation cover in coastal floodplains and wetlands for

  9. Changes in soil organic carbon fractions after remediation of a coastal floodplain soil.

    PubMed

    Wong, V N L; McNaughton, C; Pearson, A

    2016-03-01

    Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise to form coastal acid sulfate soils (CASS) and contain high concentrations of acidity and trace metals. CASS are found on every continent globally except Antarctica. When sulfidic sediments are oxidised, scalds can form, which are large bare patches without vegetation. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a CASS scald. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m (426 Mg C/ha, 478 Mg C/ha and 473 Mg C/ha at sites C, LO and LM, respectively). The particulate organic C (POC) fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Reformation of acid volatile sulfide (AVS) occurred throughout the profile at site LM, whereas only limited AVS reformation occurred at sites LO and C. Higher AVS at site LM may be linked to the additional source of organic matter provided by the mulch. POC can also potentially contribute to decreasing acidity as a labile SOC source for Fe(3+) and SO4(2-) reduction. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production. These results highlight the importance of maintaining vegetation cover in coastal floodplains and wetlands for

  10. Pyrolysis of wetland biomass waste: Potential for carbon sequestration and water remediation.

    PubMed

    Cui, Xiaoqiang; Hao, Hulin; He, Zhenli; Stoffella, Peter J; Yang, Xiaoe

    2016-05-15

    Management of biomass waste is crucial to the efficiency and sustainable operation of constructed wetlands. In this study, biochars were prepared using the biomass of 22 plant species from constructed wetlands and characterized by BET-N2 surface area analysis, FTIR, TGA, SEM, EDS, and elemental compositions analysis. Biochar yields ranged from 32.78 to 49.02%, with mesopores dominating the pore structure of most biochars. The biochars had a R50 recalcitrance index of class C and the carbon sequestration potential of 19.4-28%. The aquatic plant biomass from all the Chinese constructed wetlands if made into biochars has the potential to sequester 11.48 Mt carbon yr(-1) in soils over long time periods, which could offset 0.4% of annual CO2 emissions from fossil fuel combustion in China. In terms of adsorption capacity for selected pollutants, biochar derived from Canna indica plant had the greatest adsorption capacity for Cd(2+) (98.55 mg g(-1)) and NH4(+) (7.71 mg g(-1)). Whereas for PO4(3-), Hydrocotyle verticillata derived biochar showed the greatest adsorption capacities (2.91 mg g(-1)). The results from this present study demonstrated that wetland plants are valuable feedstocks for producing biochars with potential application for carbon sequestration and contaminant removal in water remediation.

  11. Pyrolysis of wetland biomass waste: Potential for carbon sequestration and water remediation.

    PubMed

    Cui, Xiaoqiang; Hao, Hulin; He, Zhenli; Stoffella, Peter J; Yang, Xiaoe

    2016-05-15

    Management of biomass waste is crucial to the efficiency and sustainable operation of constructed wetlands. In this study, biochars were prepared using the biomass of 22 plant species from constructed wetlands and characterized by BET-N2 surface area analysis, FTIR, TGA, SEM, EDS, and elemental compositions analysis. Biochar yields ranged from 32.78 to 49.02%, with mesopores dominating the pore structure of most biochars. The biochars had a R50 recalcitrance index of class C and the carbon sequestration potential of 19.4-28%. The aquatic plant biomass from all the Chinese constructed wetlands if made into biochars has the potential to sequester 11.48 Mt carbon yr(-1) in soils over long time periods, which could offset 0.4% of annual CO2 emissions from fossil fuel combustion in China. In terms of adsorption capacity for selected pollutants, biochar derived from Canna indica plant had the greatest adsorption capacity for Cd(2+) (98.55 mg g(-1)) and NH4(+) (7.71 mg g(-1)). Whereas for PO4(3-), Hydrocotyle verticillata derived biochar showed the greatest adsorption capacities (2.91 mg g(-1)). The results from this present study demonstrated that wetland plants are valuable feedstocks for producing biochars with potential application for carbon sequestration and contaminant removal in water remediation. PMID:26978731

  12. Remediation of heavy metal contaminated groundwater originated from abandoned mine using lime and calcium carbonate.

    PubMed

    Lee, Minhee; Paik, In Sung; Kim, Insu; Kang, Hyunmin; Lee, Sanghoon

    2007-06-01

    Column and pilot scale experiments for a chemical treatment involving the use of coagulants to remediate heavy metal contaminated groundwater were performed. Granulated lime (Ca(OH)(2)) and calcium carbonate (CaCO(3)) were used as coagulants and contaminated groundwater obtained at an abandoned Fe-mine in Korea was used for the experiments. The main removal mechanism of heavy metals in the experiments was "sweep precipitation" by coagulation. Using granulated lime as a coagulant in the column experiment, more than 98% of As and Ni were removed from artificially contaminated water. When granulated calcium carbonate was used in the artificially contaminated water, the removal efficiencies of Ni and Zn were more than 97%, but As removal efficiency was lower than 50%. For the continuous column experiment with mixed lime and calcium carbonate at a 1:1 (v/v) ratio, almost all As was removed and more than 98 % of Ni was removed. For pilot scale experiments (acryl tank: 34 cm in length and 24 cm in diameter), the removal efficiencies of As and Cd were above 96% for 150l groundwater treatment and their accumulated removal capacities linearly maintained. This suggests that coagulants could treat more than 22 times greater groundwater volume compared with the volume of coagulants used.

  13. Carbon Tetrachloride Partition Coefficients Measured by Aqueous Sorption to Hanford Sediments from Operable Units 200-UP-1 and 200-ZP-1

    SciTech Connect

    Wellman, Dawn M.; Riley, Robert G.; Cordova, Elsa A.; Parker, Kent E.; Mitroshkov, Alexandre V.

    2007-09-30

    Kd values obtained on sediment samples from 200-UP-1 and 10-ZP-1 contribute to a larger Kd database that exists for other Hanford sediments, and contains significant desorption data for CCl4. Adsorption results presented here validate the use of a linear adsorption isotherm (Kd) to predict short contact time CCl4 adsorption to sediments in 200-UP-1 groundwater plume for a distinct ranges in CCl4 concentration. However, this does not imply that values of Kd will be constant if the groundwater chemical composition at 200-UP-1 changes with space or time. Additionally, results presented here suggest the potential significance of slower intraparticle diffusion on the long-term fate of CCl4 within the subsurface Hanford environment. Such behavior could afford prolonged desorption of CCl4 and serve as a long-term source of contaminant CCl4 to the aquifer. Further evaluation of possible bimodal sorption behavior for CCl4 and the mechanism of CCl¬4 sequestration should be the subject of future investigations to provide a thorough, mechanistic understanding of the retention and long-term fate of CCl4. Comparison of previous data with new results (e.g., from this study) will allow inferences to be made on how the 200-UP-1 Kd values for CCl4 may compare with sediments from other Hanford locations. This site-specific sorption data, when complemented by the chemical, geologic, mineralogic, hydrologic, and physical characterization data that are also being collected (see Sampling and Analysis Plan for the 200-UP-1 Groundwater Monitoring Well Network, DOE 2002) can be used to develop a robust, scientifically defensible data base to allow risk predictions to be generated and to aid in future remediation decisions for the 200-UP-1 and 200-ZP-1 operable units.

  14. Monitoring trichloroethene remediation at an iron permeable reactive barrier using stable carbon isotopic analysis.

    PubMed

    VanStone, Nancy; Przepiora, Andrzej; Vogan, John; Lacrampe-Couloume, Georges; Powers, Brian; Perez, Ernesto; Mabury, Scott; Sherwood Lollar, Barbara

    2005-08-01

    Stable carbon isotopic analysis, in combination with compositional analysis, was used to evaluate the performance of an iron permeable reactive barrier (PRB) for the remediation of ground water contaminated with trichloroethene (TCE) at Spill Site 7 (SS7), F.E. Warren Air Force Base, Wyoming. Compositional data indicated that although the PRB appeared to be reducing TCE to concentrations below treatment goals within and immediately downgradient of the PRB, concentrations remained higher than expected at wells further downgradient (i.e. >9 m) of the PRB. At two wells downgradient of the PRB, TCE concentrations were comparable to upgradient values, and delta13C values of TCE at these wells were not significantly different than upgradient values. Since the process of sorption/desorption does not significantly fractionate carbon isotope values, this suggests that the TCE observed at these wells is desorbing from local aquifer materials and was present before the PRB was installed. In contrast, three other downgradient wells show significantly more enriched delta13C values compared to the upgradient mean. In addition, delta13C values for the degradation products of TCE, cis-dichloroethene and vinyl chloride, show fractionation patterns expected for the products of the reductive dechlorination of TCE. Since concentrations of both TCE and degradation products drop to below detection limit in wells within the PRB and directly below it, these downgradient chlorinated hydrocarbon concentrations are attributed to desorption from local aquifer material. The carbon isotope values indicate that this dissolved contaminant is subject to local degradation, likely due to in situ microbial activity.

  15. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules.

    PubMed

    Dawson, Elizabeth A; Parkes, Gareth M B; Bond, Gary; Mao, Runjie

    2009-03-01

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated in the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration.

  16. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules

    SciTech Connect

    Dawson, Elizabeth A.; Parkes, Gareth M. B.; Bond, Gary; Mao, Runjie

    2009-03-15

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated in the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration.

  17. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules

    NASA Astrophysics Data System (ADS)

    Dawson, Elizabeth A.; Parkes, Gareth M. B.; Bond, Gary; Mao, Runjie

    2009-03-01

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated in the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration.

  18. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules.

    PubMed

    Dawson, Elizabeth A; Parkes, Gareth M B; Bond, Gary; Mao, Runjie

    2009-03-01

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated in the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration. PMID:19334935

  19. Sorption of priority pollutants to biochars and activated carbons for application to soil and sediment remediation

    NASA Astrophysics Data System (ADS)

    Beckingham, B.; Gomez-Eyles, J. L.; Kwon, S.; Riedel, G.; Gilmour, C.; Ghosh, U.

    2012-04-01

    The effectiveness of different biochars in comparison to 2 commercially available activated carbons (ACs) to sorb polychlorinated biphenyls (PCBs) and mercury (Hg) was assessed, with the aim of identifying promising materials for application to soil and sediment remediation and elucidating material properties that may enhance pollutant binding potential. Biochars studied were produced from pine dust, peanut hull, barley straw, and acai pit in addition to steam-activated biochars made from poultry litter (chicken and turkey). Aqueous concentrations of PCBs were measured using a polyoxymethylene passive sampling technique allowing a very low environmentally-relevant concentration range to be examined. Mercury pH-edge isotherms were conducted at relatively high concentrations in a wide pH range (pH 3-11). Sorption of Hg at low concentrations was also performed with ACs and two other biochars made from a marsh reed and a hard wood. Organic contaminant isotherms were analyzed by the Freundlich model, and Freundlich sorption coefficients (KFr) were normalized to a single concentration to allow comparison among materials (i.e. Kd). Values of Kd were related to the sorbent surface area, with sorption being greater for ACs than activated biochars, followed by unactivated biochars. ACs also had higher carbon content (80-90%) than biochars (22 - 77%). This sorption trend would thus be expected for adsorption of hydrophobic compounds to black carbon surfaces. In contrast, at high concentration all biochars removed more Hg from solution than ACs. Steam-activated poultry litter biochars showed the best performance, with consistent removal of >99.7% Hg over the entire pH range. The relatively high sulfur and phosphate content of these materials likely contribute to this enhanced Hg sorption. Also, owing to their lower pyrolysis temperatures relative to ACs, biochars are reported to have a greater surface group functionality which can enhance cation sorption. The importance of

  20. Interim measure conceptual design for remediation at the former CCC/USDA grain storage facility at Centralia, Kansas : pilot test and remedy implementation.

    SciTech Connect

    LaFreniere, L. M.; Environmental Science Division

    2007-11-09

    carbon tetrachloride in groundwater and soil, the CCC/USDA recommends initial short-term, field-scale pilot testing of a remedial approach that employs in situ chemical reduction (ISCR), in the form of a commercially available material marketed by Adventus Americas, Inc., Freeport, Illinois (http://www.adventusgroup.com). If the pilot test is successful, it will be followed by a request for KDHE authorization of full implementation of the ISCR approach. In the recommended ISCR approach, the Adventus EHC{reg_sign} material--a proprietary mixture of food-grade organic carbon and zero-valent iron--is introduced into the subsurface, where the components are released slowly into the formation. The compounds create highly reducing conditions in the saturated zone and the overlying vadose zone. These conditions foster chemical and biological reductive dechlorination of carbon tetrachloride. The anticipated effective lifetime of the EHC compounds following injection is 1-5 yr. Although ISCR is a relatively innovative remedial approach, the EHC technology has been demonstrated to be effective in the treatment of carbon tetrachloride contamination in groundwater and has been employed at a carbon tetrachloride contamination site elsewhere in Kansas (Cargill Flour Mill and Elevator, Wellington, Kansas; KDHE Project Code C209670158), with the approval of the KDHE. At Centralia, the CCC/USDA recommends use of the ISCR approach initially in a short-term pilot test addressing the elevated carbon tetrachloride levels identified in one of three persistently highly contaminated areas ('hot-spot areas') in the groundwater plume. In this test, a three-dimensional grid pattern of direct-push injection points will be used to distribute the EHC material (in slurry or aqueous form) throughout the volume of the contaminated aquifer and (in selected locations) the vadose zone in the selected hot-spot area. Injection of the EHC material will be conducted by a licensed contractor, under the

  1. Carbonate minerals in porous media decrease mobility of polyacrylic acid modified zero-valent iron nanoparticles used for groundwater remediation.

    PubMed

    Laumann, Susanne; Micić, Vesna; Lowry, Gregory V; Hofmann, Thilo

    2013-08-01

    The limited transport of nanoscale zero-valent iron (nZVI) in porous media is a major obstacle to its widespread application for in situ groundwater remediation. Previous studies on nZVI transport have mainly been carried out in quartz porous media. The effect of carbonate minerals, which often predominate in aquifers, has not been evaluated to date. This study assessed the influence of the carbonate minerals in porous media on the transport of polyacrylic acid modified nZVI (PAA-nZVI). Increasing the proportion of carbonate sand in the porous media resulted in less transport of PAA-nZVI. Predicted travel distances were reduced to a few centimeters in pure carbonate sand compared to approximately 1.6 m in quartz sand. Transport modeling showed that the attachment efficiency and deposition rate coefficient increased linearly with increasing proportion of carbonate sand.

  2. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method.

    PubMed

    Ouhadi, V R; Yong, R N; Shariatmadari, N; Saeidijam, S; Goodarzi, A R; Safari-Zanjani, M

    2010-01-15

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of "calcite or carbonate" (CaCO(3)) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates. PMID:19733966

  3. Multifunctional iron-carbon nanocomposites through an aerosol-based process for the in situ remediation of chlorinated hydrocarbons.

    PubMed

    Zhan, Jingjing; Kolesnichenko, Igor; Sunkara, Bhanukiran; He, Jibao; McPherson, Gary L; Piringer, Gerhard; John, Vijay T

    2011-03-01

    Spherical iron-carbon nanocomposites were developed through a facile aerosol-based process with sucrose and iron chloride as starting materials. These composites exhibit multiple functionalities relevant to the in situ remediation of chlorinated hydrocarbons such as trichloroethylene (TCE). The distribution and immobilization of iron nanoparticles on the surface of carbon spheres prevents zerovalent nanoiron aggregation with maintenance of reactivity. The aerosol-based carbon microspheres allow adsorption of TCE, thus removing dissolved TCE rapidly and facilitating reaction by increasing the local concentration of TCE in the vicinity of iron nanoparticles. The strongly adsorptive property of the composites may also prevent release of any toxic chlorinated intermediate products. The composite particles are in the optimal range for transport through groundwater saturated sediments. Furthermore, those iron-carbon composites can be designed at low cost, the process is amenable to scale-up for in situ application, and the materials are intrinsically benign to the environment.

  4. Remediation of an aquifer polluted with dissolved tetrachloroethylene by an array of wells filled with activated carbon.

    PubMed

    Bortone, I; Di Nardo, A; Di Natale, M; Erto, A; Musmarra, D; Santonastaso, G F

    2013-09-15

    In this work, an array of deep passive wells filled with activated carbon, namely a Discontinuous Permeable Adsorptive Barrier (PAB-D), has been proposed for the remediation of an aquifer contaminated by tetrachloroethylene (PCE). The dynamics of the aquifer in the particular PAB-D configuration chosen, including the contaminant transport in the aquifer and the adsorption onto the barrier material, has been accurately performed by means of a computer code which allows describing all the phenomena occurring in the aquifer, simultaneously. A PAB-D design procedure is presented and the main dimensions of the barrier (number and position of passive wells) have been evaluated. Numerical simulations have been carried out over a long time span to follow the contaminant plume and to assess the effectiveness of the remediation method proposed. The model results show that this PAB-D design allows for a complete remediation of the aquifer under a natural hydraulic gradient, the PCE concentrations flowing out of the barrier being always lower than the corresponding Italian regulation limit. Finally, the results have been compared with those obtained for the design of a more traditional continuous barrier (PAB-C) for the same remediation process.

  5. Ultrasonic process for remediation of organics-contaminated groundwater/wastewater

    SciTech Connect

    Wu, J.M.; Peters, R.W.

    1995-07-01

    A technology is being developed that employs ultrasonic-wave energy for remediation of groundwater/wastewater contaminated with volatile organic compounds such as carbon tetrachloride (CCl{sub 4}) and trichloroethylene (TCE). This paper presents the updated results of a laboratory investigation of ultrasonic groundwater remediation using synthetic groundwaters prepared with laboratory deionized water. Key process parameters investigated included steady-state temperature, contaminant concentration, solution pH, sonication time, and intensity of the applied ultrasonics-wave energy. High destruction efficiencies of the target contaminants were achieved, and the sonication time required for a given degree of destruction decreased with increasing intensity of the applied ultrasonic energy. The sonication time can be further reduced by adding a chemical oxidant such as hydrogen peroxide.

  6. A reactor model for pulsed pumping groundwater remediation.

    PubMed

    Tenney, C M; Lastoskie, C M; Dybas, M J

    2004-11-01

    A hybrid in situ bioremediation/pulsed pumping strategy has been developed to cost effectively remediate a carbon tetrachloride plume in Schoolcraft, Michigan. The pulsed pumping system uses a line of alternating injection and extraction wells perpendicular to the direction of natural groundwater flow. The wells pump periodically to clean the recirculation zone between adjacent wells. During the pump-off phase, natural groundwater flow brings new contaminant into the recirculation zone. The wells are pumped again prior to breakthrough of contaminant from the recirculation zone. A computationally efficient reactor model has been developed, which conceptually divides the aquifer into injection, extraction, and recirculation zones, which are represented by a network of chemical reactors. Solute concentration histories from three-dimensional finite difference simulations and from field data confirm the reactor model predictions. The reactor model is used to investigate the optimal well configuration, pumping rate, and pumping schedule for achieving maximum pollutant degradation.

  7. Aquifer Testing Recommendations for Well 299-W15-225: Supporting Phase I of the 200-ZP-1 Groundwater Operable Unit Remedial Design

    SciTech Connect

    Spane, Frank A.; Newcomer, Darrell R.

    2009-03-10

    Aquifer characterization needs are currently being assessed to optimize pump-and-treat remedial strategies within the 200-ZP-1 Operable Unit (OU), specifically for the immediate area of the 241-TX-TY Tank Farm. Currently, 14 extraction wells are actively used in the Interim Record of Decision ZP-1 pump-and-treat system to remediate the existing groundwater contamination within this general area. Four of these wells (299-W15-40, 299-W15-43, 299-W15-44, and 299-W15-765) are targeted to remediate contamination within the immediate 241-TX-TY Tank Farm area. The major contaminant of concern (COC) for the 200-ZP-1 OU is carbon tetrachloride. Other COC’s include total chromium (trivalent [III] and hexavalent [VI], nitrate, trichloroethlyene, iodine-129, technetium-99, and tritium.

  8. MNA As A Remedy For Arsenic Mobilized By Anthropogenic Inputs Of Organic Carbon

    EPA Science Inventory

    The potential application of monitored natural attenuation (MNA) as a remedy for ground water contaminated with arsenic (As) is examined for a subset of contaminated sites, specifically those where naturally occurring As has been mobilized due to localized anthropogenic organic c...

  9. Recommendations for Remedial Action at Everest, Kansas.

    SciTech Connect

    LaFreniere, L. M.

    2007-02-15

    On September 7, 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) presented a Scoping Memo (Argonne 2005) for preliminary consideration by the Kansas Department of Health and Environment (KDHE). This document suggested possible remedial options for the carbon tetrachloride contamination in groundwater at Everest, Kansas. The suggested approaches were discussed by representatives of the KDHE, the CCC/USDA, and Argonne at the KDHE office in Topeka on September 8-9, 2005, along with other technical and logistic issues related to the Everest site. In response to these discussions, the KDHE recommended (KDHE 2005) evaluation of several remedial processes, either alone or in combination, as part of a Corrective Action Study (CAS) for Everest. The primary remedial processes suggested by the KDHE included the following: (1) Hydraulic control by groundwater extraction with aboveground treatment; (2) Air sparging-soil vapor extraction (SVE) in large-diameter boreholes; and (3) Phytoremediation. As a further outcome of the 2005 meeting and as a precursor to the proposed CAS, the CCC/USDA completed the following supplemental investigations at Everest to address several specific technical concerns discussed with the KDHE: (1) Construction of interpretive cross sections at strategic locations selected by the KDHE along the main plume migration pathway, to depict the hydrogeologic characteristics affecting groundwater flow and contaminant movement (Argonne 2006a); (2) A field investigation in early 2006 (Argonne 2006c), as follows: (a) Installation and testing of a production well and associated observation points, at locations approved by the KDHE, to determine the response of the Everest aquifer to groundwater extraction near the Nigh property; (b) Groundwater sampling for the analysis of volatile organic compounds (VOCs) and the installation of additional permanent monitoring points at locations selected by the KDHE, to further constrain

  10. A critical evaluation of magnetic activated carbon's potential for the remediation of sediment impacted by polycyclic aromatic hydrocarbons.

    PubMed

    Han, Zhantao; Sani, Badruddeen; Akkanen, Jarkko; Abel, Sebastian; Nybom, Inna; Karapanagioti, Hrissi K; Werner, David

    2015-04-01

    Addition of activated carbon (AC) or biochar (BC) to sediment to reduce the chemical and biological availability of organic contaminants is a promising in-situ remediation technology. But concerns about leaving the adsorbed pollutants in place motivate research into sorbent recovery methods. This study explores the use of magnetic sorbents. A coal-based magnetic activated carbon (MAC) was identified as the strongest of four AC and BC derived magnetic sorbents for polycyclic aromatic hydrocarbons (PAHs) remediation. An 8.1% MAC amendment (w/w, equal to 5% AC content) was found to be as effective as 5% (w/w) pristine AC in reducing aqueous PAHs within three months by 98%. MAC recovery from sediment after three months was 77%, and incomplete MAC recovery had both, positive and negative effects. A slight rebound of aqueous PAH concentrations was observed following the MAC recovery, but aqueous PAH concentrations then dropped again after six months, likely due to the presence of the 23% unrecovered MAC. On the other hand, the 77% recovery of the 8.1% MAC dose was insufficient to reduce ecotoxic effects of fine grained AC or MAC amendment on the egestion rate, growth and reproduction of the AC sensitive species Lumbriculus variegatus.

  11. Decommissioning of the remediation systems at Waverly, Nebraska, in 2011-2012.

    SciTech Connect

    LaFreniere, L. M.

    2012-06-29

    The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility in Waverly, Nebraska, from 1952 to 1974. During this time, the grain fumigant '80/20' (carbon tetrachloride/carbon disulfide) was used to preserve stored grain. In 1982, sampling by the U.S. Environmental Protection Agency (EPA) found carbon tetrachloride contamination in the town's groundwater. After an investigation of the contaminant distribution, the site was placed on the National Priority List (NPL) in 1986, and the CCC/USDA accepted responsibility for the contamination. An Interagency Compliance Agreement between the EPA and the CCC/USDA was finalized in May 1988 (EPA 1990). The EPA (Woodward-Clyde Consultants, contractor) started immediate cleanup efforts in 1987 with the installation of an air stripper, a soil vapor extraction system, a groundwater extraction well, and groundwater and soil gas monitoring wells (Woodward-Clyde 1986, 1988a,b). After the EPA issued its Record of Decision (ROD; EPA 1990), the CCC/USDA (Argonne National Laboratory, contractor) took over operation of the treatment systems. The CCC/USDA conducted a site investigation (Argonne 1991, 1992a,b), during which a carbon tetrachloride plume in groundwater was discovered northeast of the former facility. This plume was not being captured by the existing groundwater extraction system. The remediation system was modified in 1994 (Argonne 1993) with the installation of a second groundwater extraction well to contain the contamination further. Subsequently, a detailed evaluation of the system resulted in a recommendation to pump only the second well to conserve water in the aquifer (Argonne 1995). Sampling and analysis after implementation of this recommendation showed continued decreases in the extent and concentrations of the contamination with only one well pumping (Argonne 1999). The CCC/USDA issued quarterly monitoring reports from 1988 to 2009. Complete documentation of

  12. Remediation of contaminated subsurface materials by a metal-reducing bacterium

    SciTech Connect

    Gorby, Y.A.; Amonette, J.E.; Fruchter, J.S.

    1994-11-01

    A biotic approach for remediating subsurface sediments and groundwater contaminated with carbon tetrachloride (CT) and chromium was evaluated. Cells of the Fe(iii)-reducing bacterium strain BrY were added to sealed, anoxic flasks containing Hanford groundwater, natural subsurface sediments, and either carbon tetrachloride, CT, or oxidized chromium, Cr(VI). With lactate as the electron donor, BrY transformed CT to chloroform (CF), which accumulated to about 1 0 % of the initial concentration of CT. The remainder of the CT was transformed to unidentified, nonvolatile compounds. Transformation of CT by BrY was an indirect process Cells reduced solid phase Fe(ill) to chemically reactive FE(II) that chemically transformed the chlorinated contaminant. Cr(VI), in contrast, was reduced by a direct enzymatic reaction in the presence or absence of Fe(III)-bearing sediments. These results demonstrate that Fe(ill)-reducing bacteria provide potential for transforming CT and for reducing CR(VI) to less toxic Cr(III). Technologies for stimulating indigenous populations of metal-reducing bacteria or for introducing specific metal-reducing bacteria to the subsurface are being investigated.

  13. An approach for assessing total instrumental uncertainty in compound-specific carbon isotope analysis: implications for environmental remediation studies.

    PubMed

    Lollar, Barbara Sherwood; Hirschorn, Sarah K; Chartrand, Michelle M G; Lacrampe-Couloume, Georges

    2007-05-01

    Determination of compound-specific carbon isotope values by continuous flow isotope ratio mass spectrometry is impacted by variation in several routine operating parameters of which one of the most important is signal size, or linearity. Experiments were carried out to evaluate the implications of these operating parameters on both reproducibility and accuracy of delta13C measurements. A new method is described for assessing total instrumental uncertainty of routine compound-specific delta13C analysis, incorporating both accuracy and reproducibility. These findings have important implications for application of compound-specific isotope analysis in environmental geochemistry and in particular for the rapidly developing field of isotopic investigation of biodegradation and remediation of organic chemicals in contaminant hydrogeology. PMID:17391005

  14. An approach for assessing total instrumental uncertainty in compound-specific carbon isotope analysis: implications for environmental remediation studies.

    PubMed

    Lollar, Barbara Sherwood; Hirschorn, Sarah K; Chartrand, Michelle M G; Lacrampe-Couloume, Georges

    2007-05-01

    Determination of compound-specific carbon isotope values by continuous flow isotope ratio mass spectrometry is impacted by variation in several routine operating parameters of which one of the most important is signal size, or linearity. Experiments were carried out to evaluate the implications of these operating parameters on both reproducibility and accuracy of delta13C measurements. A new method is described for assessing total instrumental uncertainty of routine compound-specific delta13C analysis, incorporating both accuracy and reproducibility. These findings have important implications for application of compound-specific isotope analysis in environmental geochemistry and in particular for the rapidly developing field of isotopic investigation of biodegradation and remediation of organic chemicals in contaminant hydrogeology.

  15. Developing microbe–plant interactions for applications in plant‐growth promotion and disease control, production of useful compounds, remediation and carbon sequestration

    PubMed Central

    Wu, Cindy H.; Bernard, Stéphanie M.; Andersen, Gary L.; Chen, Wilfred

    2009-01-01

    Summary Interactions between plants and microbes are an integral part of our terrestrial ecosystem. Microbe–plant interactions are being applied in many areas. In this review, we present recent reports of applications in the areas of plant‐growth promotion, biocontrol, bioactive compound and biomaterial production, remediation and carbon sequestration. Challenges, limitations and future outlook for each field are discussed. PMID:21255275

  16. Developing microbe-plant interactions for applications in plant-growth promotion and disease control, production of useful compounds, remediation, and carbon sequestration

    SciTech Connect

    Wu, C.H.; Bernard, S.; Andersen, G.L.; Chen, W.

    2009-03-01

    Interactions between plants and microbes are an integral part of our terrestrial ecosystem. Microbe-plant interactions are being applied in many areas. In this review, we present recent reports of applications in the areas of plant-growth promotion, biocontrol, bioactive compound and biomaterial production, remediation and carbon sequestration. Challenges, limitations and future outlook for each field are discussed.

  17. Carbon supported Nano-Iron for environmental remediation: Transport observations using column tests, magnet resonance imaging and synchrotron tomography.

    NASA Astrophysics Data System (ADS)

    Busch, J.; Oswald, S. E.; Mackenzie, K.

    2012-04-01

    The use of nano-zerovalent iron (nZVI) for environmental remediation is a promising new technique for in situ remediation of contaminated groundwater. Due to its high surface area and high reactivity, nZVI is able to dechlorinate organic contaminants and render them harmless. Limited mobility, however, due to fast aggregation and sedimentation of nZVI, restricts the practical applicability for source and plume remediation. Carbo-Iron is a newly developed composite material consisting of activated carbon particles (d50 about 500 nm) that act as carrier for nZVI particles. Together with a polyanionic stabilizer (CMC) Carbo-Iron is able to form a stable injectable suspension. These particles are designed to combine the mobility of activated carbon and the reactivity of nZVI. Various methods were used to observe and describe transport properties, with a focus on column tests and tomographic methods: Column tests were performed in chromatography columns of 40 and 60 cm length, filled with sand grains or glass beads. Results indicate high mobility and breakthrough after addition of CMC, but changing transport properties at different pH and ionic strength. Magnet Resonance Imaging (MRI) and Synchrotron Imaging are technologies of growing interest in observing flow and transport in porous media. Even though both methods are based on different physical principles, both are sensible to iron loads in colloids and allow two- and three-dimensional reconstruction and visualization. Therefore both methods may principally be suitable for observing Carbo-Iron in porous media and might give information complementary to other experimental investigations. A suitable MRI method was developed using a medical MRI. The method based on T1 weighted measurement with short repetition time (TR = 7.0 ms) and echo time (TE = 2.95 ms) can detect different particle concentrations in a porous medium. The synchrotron tomography method used an energy rich (13 keV) parallel X-ray beam to collect

  18. Calcium carbonate-based permeable reactive barriers for iron and manganese groundwater remediation at landfills.

    PubMed

    Wang, Yu; Pleasant, Saraya; Jain, Pradeep; Powell, Jon; Townsend, Timothy

    2016-07-01

    High concentrations of iron (Fe(II)) and manganese (Mn(II)) reductively dissolved from soil minerals have been detected in groundwater monitoring wells near many municipal solid waste landfills. Two in situ permeable reactive barriers (PRBs), comprised of limestone and crushed concrete, were installed downgradient of a closed, unlined landfill in Florida, USA, to remediate groundwater containing high concentrations of these metals. Influent groundwater to the PRBs contained mean Fe and Mn concentrations of approximately 30mg/L and 1.62mg/L, respectively. PRBs were constructed in the shallow aquifer (maximum depth 4.6m below land surface) and groundwater was sampled from a network of nearby monitoring wells to evaluate barrier performance in removing these metals. PRBs significantly (p<0.05) removed dissolved Fe and Mn from influent groundwater; Fe was removed from influent water at average rates of 91% and 95% (by mass) for the limestone and crushed concrete PRBs, respectively, during the first year of the study. The performance of the PRBs declined after 3years of operation, with Fe removal efficiency decreasing to 64% and 61% for limestone and concrete PRBs, respectively. A comparison of water quality in shallow and deep monitoring wells showed a more dramatic performance reduction in the deeper section of the concrete PRB, which was attributed to an influx of sediment into the barrier and settling of particulates from the upper portions of the PRBs. Although removal of Fe and Mn from redox impacts was achieved with the PRBs, the short time frame of effectiveness relative to the duration of a full-scale remediation effort may limit the applicability of these systems at some landfills because of the construction costs required.

  19. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect

    Regan, A.H.; Roybal, W.T.; Ortega, R.; Palomares, M.; Rees, D.E.; Tischler, D.

    1996-06-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors have developed an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants. The authors have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the contaminants. This paper will describe the experimental hardware utilized, the experiments performed, the chemical analysis performed pre- and post-energy application, and results. In the experiments, two different halogenated liquids were used to contaminate the soil: carbon tetrachloride and 1,1,1-trichloroethane.

  20. Carbon Nanotubes in Biomedical Applications: Factors, Mechanisms, and Remedies of Toxicity.

    PubMed

    Alshehri, Reem; Ilyas, Asad Muhammad; Hasan, Anwarul; Arnaout, Adnan; Ahmed, Farid; Memic, Adnan

    2016-09-22

    Carbon nanotubes (CNTs) represent one of the most studied allotropes of carbon. The unique physicochemical properties of CNTs make them among prime candidates for numerous applications in biomedical fields including drug delivery, gene therapy, biosensors, and tissue engineering applications. However, toxicity of CNTs has been a major concern for their use in biomedical applications. In this review, we present an overview of carbon nanotubes in biomedical applications; we particularly focus on various factors and mechanisms affecting their toxicity. We have discussed various parameters including the size, length, agglomeration, and impurities of CNTs that may cause oxidative stress, which is often the main mechanism of CNTs' toxicity. Other toxic pathways are also examined, and possible ways to overcome these challenges have been discussed.

  1. Carbon Nanotubes in Biomedical Applications: Factors, Mechanisms, and Remedies of Toxicity.

    PubMed

    Alshehri, Reem; Ilyas, Asad Muhammad; Hasan, Anwarul; Arnaout, Adnan; Ahmed, Farid; Memic, Adnan

    2016-09-22

    Carbon nanotubes (CNTs) represent one of the most studied allotropes of carbon. The unique physicochemical properties of CNTs make them among prime candidates for numerous applications in biomedical fields including drug delivery, gene therapy, biosensors, and tissue engineering applications. However, toxicity of CNTs has been a major concern for their use in biomedical applications. In this review, we present an overview of carbon nanotubes in biomedical applications; we particularly focus on various factors and mechanisms affecting their toxicity. We have discussed various parameters including the size, length, agglomeration, and impurities of CNTs that may cause oxidative stress, which is often the main mechanism of CNTs' toxicity. Other toxic pathways are also examined, and possible ways to overcome these challenges have been discussed. PMID:27142556

  2. Preliminary evaluation of selected in situ remediation technologies for Volatile Organic Compound contamination at Arid sites

    SciTech Connect

    Lenhard, R.J.; Gerber, M.A.; Amonette, J.E.

    1992-10-01

    To support the Volatile Organic Compounds-Arid Site (VOC-Arid) Integrated Demonstration (ID) in its technical, logistical, institutional, and economical testing of emerging environmental management and restoration technologies. Pacific Northwest Laboratory(a) is evaluating several in situ remediation technologies for possible inclusion in the demonstration. The evaluations are made with respect to the initial focus of the VOC-Arid ID: the carbon tetrachloride contamination at the Hanford Site, where it was disposed to the vadose zone along with other volatile and nonvolatile organic wastes. heavy metals, acids. and radionuclides. The purposes of this report are (1) to identify candidate in situ technologies for inclusion in the program, (2) to evaluate the candidate technologies based on their potential applicability to VOC contamination at arid sites and geologic conditions representative of the ID host site (i.e., Hanford Site), and (3) to prioritize those technologies for future US Department of Energy (DOE) support.

  3. CARBON-BASED REACTIVE BARRIER FOR NITRATE REMEDIATION AT A FORMER SWINE CAFO

    EPA Science Inventory

    Nitrate (NO3-) is a common ground water contaminant related to agricultural activity, waste water disposal, leachate from landfills, septic systems, and industrial processes. This study reports on the performance of a carbon-based permeable reactive barrier (PRB) that was constr...

  4. PERFORMANCE EVALUATION OF A CARBON-BASED REACTIVE BARRIER FOR NITRATE REMEDIATION

    EPA Science Inventory

    Nitrate (NO3-) is a common ground water contaminant related to agricultural activity, waste water disposal, leachate from landfills, septic systems, and industrial processes. This study reports on the performance of a carbon-based permeable reactive barrier (PRB) that was constr...

  5. Interim measure conceptual design for remediation of source area contamination at Agra, Kansas.

    SciTech Connect

    LaFreniere, L. M.; Environmental Science Division

    2007-07-31

    This document presents a conceptual design for the implementation of a non-emergency interim measure (IM) at the site of the grain storage facility formerly operated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in Agra, Kansas. The IM is recommended to mitigate localized carbon tetrachloride contamination in the vadose zone soils at the former CCC/USDA facility and eliminate ongoing soil-to-groundwater contamination. The objectives of this IM conceptual design report include the following: 1. Obtain written acknowledgement from the Kansas Department of Health and the Environment (KDHE) that remediation on the former CCC/USDA property is required. 2. Provide information (IM description, justification for the IM, and project schedule) that the KDHE can include in a pending fact sheet. 3. Obtain KDHE approval for the IM conceptual design, so that the CCC/USDA can initiate a formal request for access to the privately owned property and proceed with preparation of a remedial design plan (RDP). Investigations conducted on behalf of the CCC/USDA by Argonne National Laboratory (Argonne 2006) have demonstrated that soil and groundwater at the Agra site are contaminated with carbon tetrachloride. The levels in groundwater exceed the Kansas Tier 2 Risk-Based Screening Level (RBSL) and the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 5.0 {micro}g/L for this compound. The soil and groundwater contamination identified at the former CCC/USDA facility currently poses no unacceptable health risks.

  6. Salt stress in a membrane bioreactor: dynamics of sludge properties, membrane fouling and remediation through powdered activated carbon dosing.

    PubMed

    De Temmerman, L; Maere, T; Temmink, H; Zwijnenburg, A; Nopens, I

    2014-10-15

    Membrane bioreactors are a well-established technology for wastewater treatment. However, their efficiency is adversely impacted by membrane fouling, primarily inciting very conservative operations of installations that makes them less appealing from an economic perspective. This fouling propensity of the activated sludge is closely related to system disturbances. Therefore, improved insight into the impact of fouling is crucial towards increased membrane performance. In this work, the disturbance of a salt shock was investigated with respect to sludge composition and filterability in two parallel lab-scale membrane bioreactors. Several key sludge parameters (soluble microbial products, sludge-bound extracellular polymeric substances, supramicron particle size distributions (PSD), submicron particle concentrations) were intensively monitored prior to, during, and after a disturbance to investigate its impact as well as the potential governing mechanism. Upon salt addition, the supramicron PSD immediately shifted to smaller floc sizes, and the total fouling rate increased. Following a certain delay, an increase in submicron particles, supernatant proteins, and polysaccharides was observed as well as an increase in the irreversible membrane fouling rate. Recovery from the disturbance was evidenced with a simultaneous decrease in the above mentioned quantities. A similar experiment introducing powdered activated carbon (PAC) addition used for remediation resulted in either no or less significant changes in the above mentioned quantities, signifying its potential as a mitigation strategy.

  7. Salt stress in a membrane bioreactor: dynamics of sludge properties, membrane fouling and remediation through powdered activated carbon dosing.

    PubMed

    De Temmerman, L; Maere, T; Temmink, H; Zwijnenburg, A; Nopens, I

    2014-10-15

    Membrane bioreactors are a well-established technology for wastewater treatment. However, their efficiency is adversely impacted by membrane fouling, primarily inciting very conservative operations of installations that makes them less appealing from an economic perspective. This fouling propensity of the activated sludge is closely related to system disturbances. Therefore, improved insight into the impact of fouling is crucial towards increased membrane performance. In this work, the disturbance of a salt shock was investigated with respect to sludge composition and filterability in two parallel lab-scale membrane bioreactors. Several key sludge parameters (soluble microbial products, sludge-bound extracellular polymeric substances, supramicron particle size distributions (PSD), submicron particle concentrations) were intensively monitored prior to, during, and after a disturbance to investigate its impact as well as the potential governing mechanism. Upon salt addition, the supramicron PSD immediately shifted to smaller floc sizes, and the total fouling rate increased. Following a certain delay, an increase in submicron particles, supernatant proteins, and polysaccharides was observed as well as an increase in the irreversible membrane fouling rate. Recovery from the disturbance was evidenced with a simultaneous decrease in the above mentioned quantities. A similar experiment introducing powdered activated carbon (PAC) addition used for remediation resulted in either no or less significant changes in the above mentioned quantities, signifying its potential as a mitigation strategy. PMID:24999116

  8. Mercury remediation in wetland sediment using zero-valent iron and granular activated carbon

    USGS Publications Warehouse

    Lewis, Ariel S.; Huntington, Thomas G.; Marvin-DiPasquale, Mark C.; Amirbahman, Aria

    2016-01-01

    Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were installed in a wetland fringing Hodgdon Pond (Maine, USA), and ZVI and GAC were applied. Pore-water MeHg concentrations were lower in treated compared with untreated mesocosms; however, sediment MeHg, as well as total Hg (THg), concentrations were not significantly different between treated and untreated mesocosms, suggesting that smaller pore-water MeHg concentrations in treated sediment were likely due to adsorption to ZVI and GAC, rather than inhibition of MeHg production. In laboratory experiments with intact vegetated sediment clumps, amendments did not significantly change sediment THg and MeHg concentrations; however, the mean pore-water MeHg and MeHg:THg ratios were lower in the amended sediment than the control. In the laboratory microcosms, snails (Lymnaea stagnalis) accumulated less MeHg in sediment treated with ZVI or GAC. The study results suggest that both GAC and ZVI have potential for reducing MeHg bioaccumulation in wetland sediment.

  9. Mercury remediation in wetland sediment using zero-valent iron and granular activated carbon.

    PubMed

    Lewis, Ariel S; Huntington, Thomas G; Marvin-DiPasquale, Mark C; Amirbahman, Aria

    2016-05-01

    Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were installed in a wetland fringing Hodgdon Pond (Maine, USA), and ZVI and GAC were applied. Pore-water MeHg concentrations were lower in treated compared with untreated mesocosms; however, sediment MeHg, as well as total Hg (THg), concentrations were not significantly different between treated and untreated mesocosms, suggesting that smaller pore-water MeHg concentrations in treated sediment were likely due to adsorption to ZVI and GAC, rather than inhibition of MeHg production. In laboratory experiments with intact vegetated sediment clumps, amendments did not significantly change sediment THg and MeHg concentrations; however, the mean pore-water MeHg and MeHg:THg ratios were lower in the amended sediment than the control. In the laboratory microcosms, snails (Lymnaea stagnalis) accumulated less MeHg in sediment treated with ZVI or GAC. The study results suggest that both GAC and ZVI have potential for reducing MeHg bioaccumulation in wetland sediment.

  10. Remediation of hexachlorobenzene contaminated soils by rhamnolipid enhanced soil washing coupled with activated carbon selective adsorption.

    PubMed

    Wan, Jinzhong; Chai, Lina; Lu, Xiaohua; Lin, Yusuo; Zhang, Shengtian

    2011-05-15

    The present study investigates the selective adsorption of hexachlorobenzene (HCB) from rhamnolipid solution by a powdered activated carbon (PAC). A combined soil washing-PAC adsorption technique is further evaluated on the removal of HCB from two soils, a spiked kaolin and a contaminated real soil. PAC at a dosage of 10 g L(-1) could achieve a HCB removal of 80-99% with initial HCB and rhamnolipid concentrations of 1 mg L(-1) and 3.3-25 g L(-1), respectively. The corresponding adsorptive loss of rhamnolipid was 8-19%. Successive soil washing-PAC adsorption tests (new soil sample was subjected to washing for each cycle) showed encouraging leaching and adsorption performances for HCB. When 25 g L(-1) rhamnolipid solution was applied, HCB leaching from soils was 55-71% for three cycles of washing, and HCB removal by PAC was nearly 90%. An overall 86% and 88% removal of HCB were obtained for kaolin and real soil, respectively, by using the combined process to wash one soil sample for twice. Our investigation suggests that coupling AC adsorption with biosurfactant-enhanced soil washing is a promising alternative to remove hydrophobic organic compounds from soils. PMID:21397398

  11. Evaluation of metal oxide and carbonate nanoparticle stability in soybean oil: Implications for controlled release of alkalinity during subsurface remediation

    NASA Astrophysics Data System (ADS)

    Ramsburg, C. A.; Leach, O. I.; Sebik, J.; Muller, K.

    2011-12-01

    Traditional methods for adjusting groundwater pH rely on injection of aqueous solutes and therefore, amendment distribution is reliant upon aqueous phase flow and transport. This reliance can limit mixing and sustention of amendments within the treatment zone. Oil-in-water emulsions offer an alternative for amendment delivery - one that has potential to enhance control of the distribution and release of buffering agents within the subsurface. Focus here is placed on using metal oxide and carbonate nanoparticles to release alkalinity from soybean oil, a common dispersed phase within emulsions designed to support remediation activities. Batch reactor systems were employed to examine the influence of dispersed phase composition on particle stability and solubility. The stability of uncoated MgO and CaCO3 particles in unmodified soybean oil was explored in a series of sedimentation studies conducted at solid loadings of 0.05, 0.1, and 0.2% mass. Three nominal sizes of MgO particles were examined (20, 50, and 100 nm) and one CaCO3 particle size (60 nm). Results from sedimentation studies conducted over four hours suggest that the viscosity of the soybean oil imparts a kinetic stability, for all sizes of the uncoated MgO and CaCO3 nanoparticles, which is sufficient time for particle encapsulation within oil-in-water emulsions. Based upon these results, the sedimentation of the 50 nm and 100 nm MgO, and 60 nm CaCO3 particles was assessed over longer durations (≥72 hr). Results from these stability tests suggest that the 50 nm and 100 nm MgO particles have greater kinetic stability than the 60 nm CaCO3. Batch studies were also used to assess the influence of n-butanol, a co-solvent hypothesized to aid in controlling the rate of alkalinity release, on phase behavior and metal (Mg2+ and Ca2+) solubility. Phase behavior studies suggest that n-butanol has a limited region of miscibility within the soybean oil-water system. Use of n-butanol and water within this region of

  12. THERMAL REMEDIATION

    EPA Science Inventory

    Thermal remediation is being proposed by Region I for remediation of the overburden soil and groundwater at the Solvent Recovery Services New England Superfund site. This presentation at the public meeting will acquaint area residents with thermal remediation. The two types of ...

  13. Long-term Stewardship of Mixed Wastes: Passive Reactive Barriers for Simultaneous In Situ Remediation of Chlorinated Solvent, Heavy Metal and Radioactive

    SciTech Connect

    Gerlach, Robin

    2005-06-01

    This project report addresses one part of a 3-way collaboration between researchers (Drs. Robin Gerlach and Al Cunningham) at Montana State University's (MSU's) Center for Biofilm Engineering (CBE), (Dr. Brent Peyton at) the WSU/NSF IGERT Center for Multiphase Environmental Research (CMER) at Washington State University (WSU), and (Drs. William Apel and Frank Roberto at) the Biotechnology Department at the INEEL. Each part of this project is funded under a different contract with the Science Division of the US Department of Energy. The project is designed to evaluate the possibility to develop a subsurface remediation technology for mixed wastes at Department of Energy sites using a group of common soil bacteria of the genus Cellulomonas. We are seeking to gain a better understanding of microbial transformation of chromium, uranium, and carbon tetrachloride by Cellulomonas spp. in simulated subsurface environments.

  14. TRANSFORMATION OF CARBON TETRACHLORIDE BY PYRITE IN AQUEOUS SOLUTION

    EPA Science Inventory

    The reactivity of Cc4 with pyrite was investigated by measuring the CC14 transformation rates and products under aerobic and anaerobic conditions. Under all reaction conditions, >90% of the CC14 was transformed within 12- 36 days in the presence o...

  15. Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines.

    PubMed

    Mulopo, J; Radebe, V

    2012-01-01

    The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO(3) recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO(3) recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO(3).

  16. Concerning Remediation

    ERIC Educational Resources Information Center

    Pace, John P.

    1977-01-01

    The author argues that the key to teaching remedial mathematics is to persuade students to believe that they will advance intellectually by learning mathematics, and that this advance will increase the possibilities open to them. (SD)

  17. Authorized Limit Evaluation of Spent Granular Activated Carbon Used for Vapor-Phase Remediation at the Lawrence Livermore National Laboratory Livermore, California

    SciTech Connect

    Devany, R; Utterback, T

    2007-01-11

    This report provides a technical basis for establishing radiological release limits for granular activated carbon (GAC) containing very low quantities of tritium and radon daughter products generated during environmental remediation activities at Lawrence Livermore National Laboratory (LLNL). This evaluation was conducted according to the Authorized Limit procedures specified in United States Department of Energy (DOE) Order 5400.5, Radiation Protection of the Public and the Environment (DOE, 1993) and related DOE guidance documents. The GAC waste is currently being managed by LLNL as a Resource Conservation and Recovery Act (RCRA) mixed waste. Significant cost savings can be achieved by developing an Authorized Limit under DOE Order 5400.5 since it would allow the waste to be safely disposed as a hazardous waste at a permitted off-site RCRA treatment and disposal facility. LLNL generates GAC waste during vapor-phase soil remediation in the Trailer 5475 area. While trichloroethylene and other volatile organic compounds (VOCs) are the primary targets of the remedial action, a limited amount of tritium and radon daughter products are contained in the GAC at the time of disposal. As defined in DOE Order 5400.5, an Authorized Limit is a level of residual radioactive material that will result in an annual public dose of 100 milliroentgen-equivalent man per year (mrem/year) or less. In 1995, DOE issued additional release requirements for material sent to a landfill that is not an authorized low-level radioactive waste disposal facility. Per guidance, the disposal site will be selected based on a risk/benefit assessment under the As-Low-As-Reasonably-Achievable (ALARA) process while ensuring that individual doses to the public are less than 25 mrem in a year, ground water is protected, the release would not necessitate further remedial action for the disposal site, and the release is coordinated with all appropriate authorities. The 1995 release requirements also state

  18. Colloidal activated carbon for in-situ groundwater remediation--Transport characteristics and adsorption of organic compounds in water-saturated sediment columns.

    PubMed

    Georgi, Anett; Schierz, Ariette; Mackenzie, Katrin; Kopinke, Frank-Dieter

    2015-08-01

    Colloidal activated carbon can be considered as a versatile adsorbent and carrier material for in-situ groundwater remediation. In analogy to other nanoremediation approaches, activated carbon colloids (ACC) can be injected into the subsurface as aqueous suspensions. Deposition of ACC on the sediment creates a sorption barrier against further spreading of hydrophobic pollutants. This study deals with the optimization of ACC and their suspensions with a focus on suspension stability, ACC mobility in saturated porous media and sorption efficiency towards organic contaminants. ACC with an appropriate particle size range (d50=0.8μm) were obtained from a commercial powdered activated carbon product by means of wet-grinding. Among the various methods tested for stabilization of ACC suspensions, addition of humic acid (HA) and carboxymethyl cellulose (CMC) showed the best results. Due to electrosteric stabilization by adsorption of CMC, suspensions remained stable even at high ACC concentrations (11gL(-1)) and conditions typical of very hard water (5mM divalent cations). Furthermore, CMC-stabilized ACC showed high mobility in a water-saturated sandy sediment column (filter coefficient λ=0.2m(-1)). Such mobility is a pre-requisite for in-situ installation of sorption or reaction barriers by simple injection-well or direct-push application of ACC suspensions. Column experiments with organic model compounds proved the efficacy of ACC deposits on sediment for contaminant adsorption and retardation under flow-through conditions. PMID:26070009

  19. Colloidal activated carbon for in-situ groundwater remediation--Transport characteristics and adsorption of organic compounds in water-saturated sediment columns.

    PubMed

    Georgi, Anett; Schierz, Ariette; Mackenzie, Katrin; Kopinke, Frank-Dieter

    2015-08-01

    Colloidal activated carbon can be considered as a versatile adsorbent and carrier material for in-situ groundwater remediation. In analogy to other nanoremediation approaches, activated carbon colloids (ACC) can be injected into the subsurface as aqueous suspensions. Deposition of ACC on the sediment creates a sorption barrier against further spreading of hydrophobic pollutants. This study deals with the optimization of ACC and their suspensions with a focus on suspension stability, ACC mobility in saturated porous media and sorption efficiency towards organic contaminants. ACC with an appropriate particle size range (d50=0.8μm) were obtained from a commercial powdered activated carbon product by means of wet-grinding. Among the various methods tested for stabilization of ACC suspensions, addition of humic acid (HA) and carboxymethyl cellulose (CMC) showed the best results. Due to electrosteric stabilization by adsorption of CMC, suspensions remained stable even at high ACC concentrations (11gL(-1)) and conditions typical of very hard water (5mM divalent cations). Furthermore, CMC-stabilized ACC showed high mobility in a water-saturated sandy sediment column (filter coefficient λ=0.2m(-1)). Such mobility is a pre-requisite for in-situ installation of sorption or reaction barriers by simple injection-well or direct-push application of ACC suspensions. Column experiments with organic model compounds proved the efficacy of ACC deposits on sediment for contaminant adsorption and retardation under flow-through conditions.

  20. Remediation of nitrate-contaminated wastewater using denitrification biofilters with straws of ornamental flowers added as carbon source.

    PubMed

    Chang, Junjun; Ma, Luyao; Zhou, Yuanyang; Zhang, Shenghua; Wang, Weilu

    2016-01-01

    Straws of four ornamental flowers (carnation, rose, lily, and violet) were added into denitrification biofilters using gravel as matrix through vertically installed perforated polyvinylchloride pipes to provide organic carbon for the treatment of nitrate-contaminated wastewater operating in batch mode. Removal efficiencies of nitrate and phosphate, as well as temporal variations of nitrogen and carbon during batches 10 and 19, were investigated and assessed. Nitrate removal was efficiently enhanced by the addition of flower straws, but decreased gradually as the organic substances were consumed. Phosphate removal was also improved, although this very limited. High nitrate removal rates were achieved during the initial 12 h in the two batches each lasting for 3 days, along with the depletion of influent dissolved oxygen due to aerobic degradation of the organic compounds. NO2(-)-N of 0.01-2.83 mg/L and NH4(+)-N of 0.02-1.69 mg/L were formed and both positively correlated to the nitrate reduced. Inorganic carbon (IC) concentrations increased during the batches and varied conversely with the nitrate contents, and could be indicative of nitrate removal due to the highly significant positive correlation between NO3(-)-N removed and IC concentration (r(2) = 0.881, p < 0.0001). It is feasible and economical to use the denitrification biofilter to treat nitrate-contaminated wastewater, although further optimization of carbon source addition is still required. PMID:27438246

  1. Remediation of nitrate-contaminated wastewater using denitrification biofilters with straws of ornamental flowers added as carbon source.

    PubMed

    Chang, Junjun; Ma, Luyao; Zhou, Yuanyang; Zhang, Shenghua; Wang, Weilu

    2016-01-01

    Straws of four ornamental flowers (carnation, rose, lily, and violet) were added into denitrification biofilters using gravel as matrix through vertically installed perforated polyvinylchloride pipes to provide organic carbon for the treatment of nitrate-contaminated wastewater operating in batch mode. Removal efficiencies of nitrate and phosphate, as well as temporal variations of nitrogen and carbon during batches 10 and 19, were investigated and assessed. Nitrate removal was efficiently enhanced by the addition of flower straws, but decreased gradually as the organic substances were consumed. Phosphate removal was also improved, although this very limited. High nitrate removal rates were achieved during the initial 12 h in the two batches each lasting for 3 days, along with the depletion of influent dissolved oxygen due to aerobic degradation of the organic compounds. NO2(-)-N of 0.01-2.83 mg/L and NH4(+)-N of 0.02-1.69 mg/L were formed and both positively correlated to the nitrate reduced. Inorganic carbon (IC) concentrations increased during the batches and varied conversely with the nitrate contents, and could be indicative of nitrate removal due to the highly significant positive correlation between NO3(-)-N removed and IC concentration (r(2) = 0.881, p < 0.0001). It is feasible and economical to use the denitrification biofilter to treat nitrate-contaminated wastewater, although further optimization of carbon source addition is still required.

  2. Reimagining Remediation

    ERIC Educational Resources Information Center

    Handel, Stephen J.; Williams, Ronald A.

    2011-01-01

    In 2007, the College Board's Community College Advisory Panel--a group of college presidents that advises the organization's membership on community college issues--asked these authors to write a paper describing effective remedial education programs. They never wrote the paper. The problem was not the lack of dedicated faculty and staff working…

  3. Toxic remediation

    DOEpatents

    Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

    1994-01-01

    What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

  4. Evaluation of biochars and activated carbons for in situ remediation of sediments impacted with organics, mercury, and methylmercury.

    PubMed

    Gomez-Eyles, Jose L; Yupanqui, Carmen; Beckingham, Barbara; Riedel, Georgia; Gilmour, Cynthia; Ghosh, Upal

    2013-12-01

    In situ amendment of activated carbon (AC) to sediments can effectively reduce the bioavailability of hydrophobic organic contaminants. While biochars have been suggested as low-cost and sustainable alternatives to ACs, there are few comparative sorption data especially for mercury (Hg) and methylmercury (MeHg) at the low porewater concentrations in sediments. Here we compare the ability of a wide range of commercially available and laboratory synthesized ACs and biochars to sorb PAHs, PCBs, DDTs, inorganic Hg, and MeHg at environmentally relevant concentrations. Compared to natural organic matter, sorption capacity for most organic compounds was at least 1-2 orders of magnitude higher for unactivated biochars and 3-4 orders of magnitude higher for ACs which translated to sediment porewater PCB concentration reductions of 18-80% for unactivated biochars, and >99% for ACs with 5% by weight amendment to sediment. Steam activated carbons were more effective than biochars in Hg sorption and translated to modeled porewater Hg reduction in the range of 94-98% for sediments with low native Kd and 31-73% for sediments with high native Kd values for Hg. Unactivated biochars were as effective as the steam activated carbons for MeHg sorption. Predicted reductions of porewater MeHg were 73-92% for sediments with low native Kd and 57-86% for sediment with high native K(d). ACs with high surface areas therefore are likely to be effective in reducing porewater concentrations of organics, Hg, and MeHg in impacted sediments. Unactivated biochars had limited effectiveness for organics and Hg but can be considered when MeHg exposure is the primary concern.

  5. Health effects of silicon tetrachloride. Report of an urban accident.

    PubMed

    Kizer, K W; Garb, L G; Hine, C H

    1984-01-01

    A spill of silicon tetrachloride (SiCl4) at a chemical plant caused the evacuation of several thousand people from an industrial park; 28 persons sought medical attention. Most of the affected individuals suffered only transient eye and upper airway irritation. Six of the plant employees were later referred for detailed evaluation of possible lung injury, but no definite evidence of SiCl4-induced pulmonary dysfunction was found. Five of these workers also experienced recurrent headaches, and two complained of pedal dysesthesias after the accident. Although the temporal relationship between the exposure and onset of these symptoms is notable, no definite etiologic relationship could be established.

  6. Electrosorption on carbon aerogel electrodes as a means of treating low-level radioactive wastes and remediating contaminated ground water

    SciTech Connect

    Tran, Tri Duc; Farmer, Joseph C.; DePruneda, Jean H.; Richardson, Jeffery H.

    1997-07-01

    A novel separation process based upon carbon aerogel electrodes has been recently developed for the efficient removal of ionic impurities from aqueous streams. This process can be used as an electrical y- regenerated alternative to ion exchange, thereby reducing-the need for large quantities of chemical regenerants. Once spent (contaminated), these regenerants contribute to the waste that must be disposed of in landfills. The elimination of such wastes is especially beneficial in situations involving radioactive contaminants, and pump and treat processing of massive volumes of ground water. A review and analysis of potential applications will be presented.

  7. The use of alkaline hydrolysis as a novel strategy for chloroform remediation: the feasibility of using construction wastes and evaluation of carbon isotopic fractionation.

    PubMed

    Torrentó, Clara; Audí-Miró, Carme; Bordeleau, Geneviève; Marchesi, Massimo; Rosell, Mònica; Otero, Neus; Soler, Albert

    2014-01-01

    Laboratory and field-scale pilot experiments were performed to evaluate the feasibility of chloroform degradation by alkaline hydrolysis and the potential of δ(13)C values to assess this induced reaction process at contaminated sites. In batch experiments, alkaline conditions were induced by adding crushed concrete (pH 12.33 ± 0.07), a filtered concrete solution (pH 12.27 ± 0.04), a filtered cement solution (pH 12.66 ± 0.02) and a pH 12 buffer solution (pH 11.92 ± 0.11). The resulting chloroform degradation after 28 days was 94, 96, 99, and 72%, respectively. The experimental data were described using a pseudo-first-order kinetic model, resulting in pseudo-first-order rate constant values of 0.10, 0.12, 0.20, and 0.05 d(-1), respectively. Furthermore, the significant chloroform carbon isotopic fractionation associated with alkaline hydrolysis of chloroform (-53 ± 3‰) and its independence from pH in the admittedly limited tested pH range imply a great potential for the use of δ(13)C values for in situ monitoring of the efficacy of remediation approaches based on alkaline hydrolysis. The carbon isotopic fractionation obtained at the lab scale allowed the calculation of the percentage of chloroform degradation in field-scale pilot experiments where alkaline conditions were induced in two recharge water interception trenches filled with concrete-based construction wastes. A maximum of approximately 30-40% of chloroform degradation was achieved during the two studied recharge periods. Although further research is required, the treatment of chloroform in groundwater through the use of concrete-based construction wastes is proposed. This strategy would also imply the recycling of construction and demolition wastes for use in value-added applications to increase economic and environmental benefits. PMID:24410407

  8. The use of alkaline hydrolysis as a novel strategy for chloroform remediation: the feasibility of using construction wastes and evaluation of carbon isotopic fractionation.

    PubMed

    Torrentó, Clara; Audí-Miró, Carme; Bordeleau, Geneviève; Marchesi, Massimo; Rosell, Mònica; Otero, Neus; Soler, Albert

    2014-01-01

    Laboratory and field-scale pilot experiments were performed to evaluate the feasibility of chloroform degradation by alkaline hydrolysis and the potential of δ(13)C values to assess this induced reaction process at contaminated sites. In batch experiments, alkaline conditions were induced by adding crushed concrete (pH 12.33 ± 0.07), a filtered concrete solution (pH 12.27 ± 0.04), a filtered cement solution (pH 12.66 ± 0.02) and a pH 12 buffer solution (pH 11.92 ± 0.11). The resulting chloroform degradation after 28 days was 94, 96, 99, and 72%, respectively. The experimental data were described using a pseudo-first-order kinetic model, resulting in pseudo-first-order rate constant values of 0.10, 0.12, 0.20, and 0.05 d(-1), respectively. Furthermore, the significant chloroform carbon isotopic fractionation associated with alkaline hydrolysis of chloroform (-53 ± 3‰) and its independence from pH in the admittedly limited tested pH range imply a great potential for the use of δ(13)C values for in situ monitoring of the efficacy of remediation approaches based on alkaline hydrolysis. The carbon isotopic fractionation obtained at the lab scale allowed the calculation of the percentage of chloroform degradation in field-scale pilot experiments where alkaline conditions were induced in two recharge water interception trenches filled with concrete-based construction wastes. A maximum of approximately 30-40% of chloroform degradation was achieved during the two studied recharge periods. Although further research is required, the treatment of chloroform in groundwater through the use of concrete-based construction wastes is proposed. This strategy would also imply the recycling of construction and demolition wastes for use in value-added applications to increase economic and environmental benefits.

  9. Integrating NZVI and carbon substrates in a non-pumping reactive wells array for the remediation of a nitrate contaminated aquifer.

    PubMed

    Hosseini, Seiyed Mossa; Tosco, Tiziana

    2015-08-01

    The work explores the efficacy of a biochemical remediation of a nitrate-contaminated aquifer by a combination of nanoscale zero-valent iron (NZVI) and bacteria supported by carbon substrates. Nitrate removal was first assessed in batch tests, and then in a laboratory bench-scale aquifer model (60cm length×40cm width×50cm height), in which a background flow was maintained. Water and natural sandy material of a stratified aquifer were used in the tests to enhance the reliability of the results. An array of non-pumping-reactive wells (NPRWs) filled with NZVI (d50=50nm, and SSA=22.5m(2)/g) mixed with carbon substrates (beech sawdust and maize cobs) was installed in the bench-scale aquifer model to intercept the flow and remove nitrate (NO3(-) conc.=105mg/l). The NPRW array was preferred to a continuous permeable reactive barrier (PRB) since wells can be drilled at greater depths compared to PRBs. The optimal well diameter, spacing among the NPRWs and number of wells in the bench-scale model were designed based on flow simulations using the semi-analytical particle tracking (advection) model, PMPATH. An optimal configuration of four wells, 35mm diameter, and capture width of 1.8 times the well diameter was obtained for a hydraulic conductivity contrast between reactive materials in the wells and aquifer media (KPM/Kaq=16.5). To avoid excessive proximity between wells, the system was designed so that the capture of the contaminated water was not complete, and several sequential arrays of wells were preferred. To simulate the performance of the array, the water that passed through the bench-scale NPRW system was re-circulated to the aquifer inlet, and a nitrate degradation below the limit target concentration (10mg/l) was obtained after 13days (corresponding to 13 arrays of wells in the field). The results of this study demonstrated that using the NZVI-mixed-carbon substrates in the NPRW system has a great potential for in-situ nitrate reduction in contaminated

  10. Remediation of contaminated marine sediment using thin-layer capping with activated carbon--a field experiment in Trondheim harbor, Norway.

    PubMed

    Cornelissen, Gerard; Kruså, Marie Elmquist; Breedveld, Gijs D; Eek, Espen; Oen, Amy M P; Arp, Hans Peter H; Raymond, Caroline; Samuelsson, Göran; Hedman, Jenny E; Stokland, Øystein; Gunnarsson, Jonas S

    2011-07-15

    In situ amendment of contaminated sediments using activated carbon (AC) is a recent remediation technique, where the strong sorption of contaminants to added AC reduces their release from sediments and uptake into organisms. The current study describes a marine underwater field pilot study in Trondheim harbor, Norway, in which powdered AC alone or in combination with sand or clay was tested as a thin-layer capping material for polycyclic aromatic hydrocarbon (PAH)-contaminated sediment. Several novel elements were included, such as measuring PAH fluxes, no active mixing of AC into the sediment, and the testing of new manners of placing a thin AC cap on sediment, such as AC+clay and AC+sand combinations. Innovative chemical and biological monitoring methods were deployed to test capping effectiveness. In situ sediment-to-water PAH fluxes were measured using recently developed benthic flux chambers. Compared to the reference field, AC capping reduced fluxes by a factor of 2-10. Pore water PAH concentration profiles were measured in situ using a new passive sampler technique, and yielded a reduction factor of 2-3 compared to the reference field. The benthic macrofauna composition and biodiversity were affected by the AC amendments, AC + clay having a lower impact on the benthic taxa than AC-only or AC + sand. In addition, AC + clay gave the highest AC recoveries (60% vs 30% for AC-only and AC + sand) and strongest reductions in sediment-to-water PAH fluxes and porewater concentrations. Thus, application of an AC-clay mixture is recommended as the optimal choice of the currently tested thin-layer capping methods for PAHs, and more research on optimizing its implementation is needed. PMID:21671651

  11. Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

    PubMed

    Ong, Wee-Jun; Tan, Lling-Lling; Ng, Yun Hau; Yong, Siek-Ting; Chai, Siang-Piao

    2016-06-22

    As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and "earth-abundant" nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The construction and characteristics of each classification of the heterojunction system will be critically reviewed, namely metal-g-C3N4, semiconductor-g-C3N4, isotype g-C3N4/g-C3N4, graphitic carbon-g-C3N4, conducting polymer-g-C3N4, sensitizer-g-C3N4, and multicomponent heterojunctions. The band structures, electronic properties, optical absorption, and interfacial charge transfer of g-C3N4-based heterostructured nanohybrids will also be theoretically discussed based on the first-principles density functional theory (DFT) calculations to provide insightful outlooks on the charge carrier dynamics. Apart from that, the advancement of the versatile photoredox applications toward artificial photosynthesis (water splitting and photofixation of CO2), environmental decontamination, and bacteria disinfection will be presented in detail. Last but not least, this comprehensive review will conclude with a summary and some invigorating perspectives on the challenges and future directions

  12. Plasma quench production of titanium from titanium tetrachloride

    SciTech Connect

    Sears, J.W.

    1994-10-01

    This project, Plasma Quench Production of Titanium from Titanium Tetrachloride, centers on developing a technique for rapidly quenching the high temperature metal species and preventing back reactions with the halide. The quenching technique chosen uses the temperature drop produced in a converging/diverging supersonic nozzle. The rapid quench provided by this nozzle prevents the back reaction of the halide and metal. The nature of the process produces nanosized particles (10 to 100 nm). The powders are collected by cyclone separators, the hydrogen flared, and the acid scrubbed. Aluminum and titanium powders have been produced in the laboratory-scale device at 1 gram per hour. Efforts to date to scale up this process have not been successful.

  13. Implications of Fe/Pd Bimetallic Nanoparticles Immobilized on Adsorptive Activated Carbon for the Remediation of Groundwater and Sediment Contaminated with PCBs

    EPA Science Inventory

    In order to respond to the current limitations and challenges in remediating groundwater and sediment contaminated with polychlorinated biphenyls (PCBs), we have recently developed a new strategy, integration of the physical adsorption of PCBs with their electrochemical dechlori...

  14. Charge transfer vibronic transitions in uranyl tetrachloride compounds;

    SciTech Connect

    Liu, G. K.; Deifel, N. P.; Cahill, C. L.

    2012-01-01

    The electronic and vibronic interactions of uranyl (UO{sub 2}){sup 2+} in three tetrachloride crystals have been investigated with spectroscopic experiments and theoretical modeling. Analysis and simulation of the absorption and photoluminescence spectra have resulted in a quantitative understanding of the charge transfer vibronic transitions of uranyl in the crystals. The spectra obtained at liquid helium temperature consist of extremely narrow zero-phonon lines (ZPL) and vibronic bands. The observed ZPLs are assigned to the first group of the excited states formed by electronic excitation from the 3{sigma} ground state into the f{sub {delta}{phi}}, orbitals of uranyl. The Huang-Rhys theory of vibronic coupling is modified successfully for simulating both the absorption and luminescence spectra. It is shown that only vibronic coupling to the axially symmetric stretching mode is Franck-Condon allowed, whereas other modes are involved through coupling with the symmetric stretching mode. The energies of electronic transitions, vibration frequencies of various local modes, and changes in the O=U=O bond length of uranyl in different electronic states and in different coordination geometries are evaluated in empirical simulations of the optical spectra. Multiple uranyl sites derived from the resolution of a superlattice at low temperature are resolved by crystallographic characterization and time- and energy-resolved spectroscopic studies. The present empirical simulation provides insights into fundamental understanding of uranyl electronic interactions and is useful for quantitative characterization of uranyl coordination.

  15. Charge transfer vibronic transitions in uranyl tetrachloride compounds

    SciTech Connect

    Liu, Guokui; Deifel, Nicholas P.; Cahill, Christopher L.; Zhurov, Vladimir V.; Pinkerton, A. Alan

    2012-01-01

    The electronic and vibronic interactions of uranyl (UO₂)2+ in three tetrachloride crystals have been investigated with spectroscopic experiments and theoretical modeling. Analysis and simulation of the absorption and photoluminescence spectra have resulted in a quantitative understanding of the charge transfer vibronic transitions of uranyl in the crystals. The spectra obtained at liquid helium temperature consist of extremely narrow zero-phonon lines (ZPL) and vibronic bands. The observed ZPLs are assigned to the first group of the excited states formed by electronic excitation from the 3σ ground state into the fδ,Φ orbitals of uranyl. The Huang–Rhys theory of vibronic coupling is modified successfully for simulating both the absorption and luminescence spectra. It is shown that only vibronic coupling to the axially symmetric stretching mode is Franck–Condon allowed, whereas other modes are involved through coupling with the symmetric stretching mode. The energies of electronic transitions, vibration frequencies of various local modes, and changes in the O=U=O bond length of uranyl in different electronic states and in different coordination geometries are evaluated in empirical simulations of the optical spectra. Multiple uranyl sites derived from the resolution of a superlattice at low temperature are resolved by crystallographic characterization and time- and energy-resolved spectroscopic studies. The present empirical simulation provides insights into fundamental understanding of uranyl electronic interactions and is useful for quantitative characterization of uranyl coordination.

  16. Reinventing Remedial Education

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2009-01-01

    Remedial education, although widely used and disguised with other names, was rarely talked about for it could tarnish a school's reputation if widely discussed. Today, more and more colleges and universities are ditching the old stigma associated with remedial education, reinventing their remedial education and retention programs and, in the…

  17. Duct Remediation Program: Remediation operations and implementation

    SciTech Connect

    Beckman, T.d.; Davis, M.M.; Karas, T.M.

    1992-11-01

    Plutonium holdup material has accumulated in the process ventilation duct systems at Rocky Flats. Non-Destructive Assay (NDA) measurements identified ducts containing this material. The Defense Nuclear Facility Safety Board and the Department of Energy established the criteria for remediation of these ducts. A remediation team was assembled and a program plan created. This program plan included activities such as fissile material accumulation identification, criticality safety assessments, radiation dose determinations, facility safety evaluations, prevention of future accumulation, and removal of holdup material. Several operational considerations had to be evaluated in determining completion of remediation.

  18. Silicon tetrachloride plasma induced grafting for starch-based composites

    NASA Astrophysics Data System (ADS)

    Ma, Yonghui C.

    Non-modified virgin starch is seldom used directly in industrial applications. Instead, it is often physically and/or chemically modified to achieve certain enhanced properties. For many of the non-food applications, these modifications involve changing its hydrophilicity to create hydrophobic starch. In this study, the hydrophobic starch was produced through silicon tetrachloride (SiCl4) plasma induced graft polymerization, so that it could be used as a renewable and biodegradable component of, or substitute for, the petrochemical-based plastics. It was suggested that this starch graft-copolymer might be used as reinforcing components in silicone-rubber materials for starch-based composites. To make this starch graft-copolymer, the ethyl ether-extracted starch powders were surface functionalized by SiCl4 plasma using a 13.56 MHz radio frequency rotating plasma reactor and subsequently stabilized by either ethylene diamine or dichlorodimethylsilane (DCDMS). The functionalized starch was then graft-polymerized with DCDMS to form polydimethylsiloxane (PDMS) layers around the starch granules. The presence of this PDMS layer was demonstrated by electron spectroscopy for chemical analysis (ESCA/XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GC-MS), thermo gravimetry/differential thermal analysis (TG/DTA), and other analyses. It was shown that the surface morphology, thermal properties, swelling characteristic, and hydrophilicity of starch were all changed due to the existence of this protective hydrophobic PDMS layer. Several different procedures to carry out the functionalization and graft polymerization steps were evaluated to improve the effectiveness of the reactions and to prevent the samples from being hydrolyzed by the grafting byproduct HCl. Actinometry, GC-MS, and residual gas analyzer (RGA) were used to investigate the mechanisms of the SiCl4 discharge and to optimize the plasma

  19. DDE remediation and degradation.

    PubMed

    Thomas, John E; Ou, Li-Tse; All-Agely, Abid

    2008-01-01

    breakdown of DDE by the extracellular lignolytic enzymes produced by white rot fungi. The addition of adjutants such as sodium ion, surfactants, and cellulose increased the rate of DDT aerobic or anaerobic degradation but did little to enhance the rate of DDE disappearance under anaerobic conditions. Only in the past decade has it been demonstrated that DDE can undergo reductive dechlorination under methanogenic and sulfidogenic conditions to form the degradation product DDMU, 1-chloro-2,2'-bis-(4'-chlorophenyl)ethane. The only pure culture reported to degrade DDE under anaerobic conditions was the denitrifier Alcaligens denitrificans. The degradation of DDE by this bacterium was enhanced by glucose, whereas biphenyl fumes had no effect. Abiotic remediation by DDE volatilization was enhanced by flooding and irrigation and deepplowing inhibited the volatilization. The use of zero-valent iron and surfactants in flooded soils enhanced DDT degradation but did not significantly alter the rate of DDE removal. Other catalysts (palladized magnesium, palladium on carbon, and nickel/aluminum alloys) degraded DDT and its metabolites, including DDE. However, these systems are often biphasic or involve explosive gases or both. Safer abiotic alternatives use UV light with titanium oxide or visible light with methylene green to degrade DDT, DDD, and DDE in aqueous or mixed solvent systems. Remediation and degradation of DDE in soil and water by phytoextraction, aerobic and anaerobic microorganisms, or abiotic methods can be accomplished. However, success has been limited, and great care must be taken that the method does not transfer the contaminants to another locale (by volatilization, deep plowing, erosion, or runoff) or to another species (by ingestion of accumulating plants or contaminated water). Although the remediation of DDT-, DDD-, and DDE-contaminated soil and water is beset with myriad problems, there remain many open avenues of research. PMID:18069646

  20. Novel crystal engineering of transition metal tetrachloride with protonated azoaromatic molecules

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Ye, Ling; Wu, Lixin

    2006-06-01

    The tetrahedally coordinated crystalline salts of transition metal (Zn(II) and Hg(II)) tetrachlorides with protonated 1,2-bis(4-pyridyl)ethylene (bpe) and trans-4,4'-azobispyridine (azp) reveal three supramolecular motifs: zig-zag chains, cyclic dimers and grommet chains linked by single N-H⋯Cl or N-H⋯Cl/C-H⋯Cl synthon. The present results enrich the reported assembling structure types of multicomponents by replacing 4,4'-bipyridine (bipy) with bpe and azp in complexing with metal chloride under acidic condition. The obtained crystals are all in monoclinic crystal system. The unit-cell dimensions of same metal coordinated with bpe and azp in HCl are similar. Crystalline salts of Zn(II) and Hg(II) tetrachlorides with H 2bpe in HCl adopt C2/ c space group, while those of Zn(II) tetrachloride in HCl and Hg(II) tetrachloride in AcOH with H 2azp adopt P2 1/ n space group. Furthermore, crystalline salt of Hg(II) with H 2azp in HCl adopts C2 space group.

  1. Investigating biochar as a tool for environmental remediation

    EPA Science Inventory

    Biochar is being proposed as a cost-effective, carbon negative soil amendment for environmental remediation. Research has demonstrated the efficacy of biochar to sorb heavy metals and agricultural chemicals from contaminated soils, thus effectively reducing the potential for met...

  2. Remedial investigation work plan for the Upper East Fork Poplar Creek characterization area, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1995-09-01

    The Oak Ridge Y-12 Plant, located within the Oak Ridge Reservation (ORR), is owned by the US Department of Energy (DOE) and managed by Lockheed Martin Energy Systems, Inc. The entire ORR was placed on the National Priorities List (NPL) of CERCLA sites in November 1989. Following CERCLA guidelines, sites under investigation require a remedial investigation (RI) to define the nature and extent of contamination, evaluate the risks to public health and the environment, and determine the goals for a feasibility study (FS) of potential remedial actions. The need to complete RIs in a timely manner resulted in the establishment of the Upper East Fork Poplar Creek (UEFPC) Characterization Area (CA) and the Bear Creek CA. The CA approach considers the entire watershed and examines all appropriate media within it. The UEFPC CA, which includes the main Y-12 Plant area, is an operationally and hydrogeologically complex area that contains numerous contaminants and containment sources, as well as ongoing industrial and defense-related activities. The UEFPC CA also is the suspected point of origin for off-site groundwater and surface-water contamination. The UEFPC CA RI also will address a carbon-tetrachloride/chloroform-dominated groundwater plume that extends east of the DOE property line into Union Valley, which appears to be connected with springs in the valley. In addition, surface water in UEFPC to the Lower East Fork Poplar Creek CA boundary will be addressed. Through investigation of the entire watershed as one ``site,`` data gaps and contaminated areas will be identified and prioritized more efficiently than through separate investigations of many discrete units.

  3. Designing Clinical Remediation Programs.

    ERIC Educational Resources Information Center

    Oleszewski, Susan C.

    1989-01-01

    Elements and considerations in the provision of effective remediation for optometry students not achieving in clinical competence are discussed. Remediation of technical, cognitive, and noncognitive skills are included. A course in professional communication offered by the Pennsylvania College of Optometry is described. (MSE)

  4. Preventing remediation problems

    SciTech Connect

    Fleming, W.H.

    1994-12-31

    Remediation, the design and construction of a remedy, typically represents the most significant portion of the cleanup process. The cost may be 5 to 10 times the cost of earlier investigation and feasibility efforts. Furthermore, the risks associated with remediation activities and their ability to meet ultimate cleanup goals and objectives are far greater than those associated with earlier efforts. Often times there are unrealistic expectations interjected throughout the design and construction process in the remediation field. The simple fact that most problems are buried, and one cannot see all that is below the ground surface provides sufficient uncertainty to result in problems. There are three key points during the remediation process which provide opportunities to prevent and avoid problems. These are: (1) during design; (2) during procurement and contracting; and (3) during construction. This paper examines actions which the author has found or believes will assist in providing a formula for success.

  5. Novel sorbents for environmental remediation

    NASA Astrophysics Data System (ADS)

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  6. Numerical investigation on three-dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere.

    PubMed

    Jianwen, Zhang; Xinxin, Yin; Yanan, Xin; Jian, Zhang; Xiaoping, Zheng; Chunming, Jiang

    2015-05-15

    The world has experienced heavy thirst of energy as it has to face a dwindling supply of fossil fuel and polycrystalline silicon photovoltaic solar energy technology has been assigned great importance. Silicon tetrachloride is the main byproducts of polysilicon industry, and it's volatile and highly toxic. Once silicon tetrachloride releases, it rapidly forms a dense gas cloud and reacts violently with water vapor in the atmosphere to form a gas cloud consisting of the mixture of silicon tetrachloride, hydrochloric acid and silicic acid, which endangers environment and people. In this article, numerical investigation is endeavored to explore the three dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere. The k-ϵ model with buoyancy correction on k is applied for turbulence closure and modified EBU model is applied to describe the hydrolysis reaction of silicon tetrachloride. It is illustrated that the release of silicon tetrachloride forms a dense cloud, which sinks onto the ground driven by the gravity and wind and spreads both upwind and downwind. Complicated interaction occurs between the silicon tetrachloride cloud and the air mass. The main body of the dense cloud moves downwind and reacts with the water vapor on the interface between the dense cloud and the air mass to generate a toxic mixture of silicon tetrachloride, hydrogen chloride and silicic acid. A large coverage in space is formed by the toxic mixture and imposes chemical hazards to the environment. The exothermic hydrolysis reaction consumes water and releases reaction heat resulting in dehydration and temperature rise, which imposes further hazards to the ecosystem over the affected space. PMID:25682513

  7. Numerical investigation on three-dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere.

    PubMed

    Jianwen, Zhang; Xinxin, Yin; Yanan, Xin; Jian, Zhang; Xiaoping, Zheng; Chunming, Jiang

    2015-05-15

    The world has experienced heavy thirst of energy as it has to face a dwindling supply of fossil fuel and polycrystalline silicon photovoltaic solar energy technology has been assigned great importance. Silicon tetrachloride is the main byproducts of polysilicon industry, and it's volatile and highly toxic. Once silicon tetrachloride releases, it rapidly forms a dense gas cloud and reacts violently with water vapor in the atmosphere to form a gas cloud consisting of the mixture of silicon tetrachloride, hydrochloric acid and silicic acid, which endangers environment and people. In this article, numerical investigation is endeavored to explore the three dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere. The k-ϵ model with buoyancy correction on k is applied for turbulence closure and modified EBU model is applied to describe the hydrolysis reaction of silicon tetrachloride. It is illustrated that the release of silicon tetrachloride forms a dense cloud, which sinks onto the ground driven by the gravity and wind and spreads both upwind and downwind. Complicated interaction occurs between the silicon tetrachloride cloud and the air mass. The main body of the dense cloud moves downwind and reacts with the water vapor on the interface between the dense cloud and the air mass to generate a toxic mixture of silicon tetrachloride, hydrogen chloride and silicic acid. A large coverage in space is formed by the toxic mixture and imposes chemical hazards to the environment. The exothermic hydrolysis reaction consumes water and releases reaction heat resulting in dehydration and temperature rise, which imposes further hazards to the ecosystem over the affected space.

  8. Cognitive Remediation in Schizophrenia

    PubMed Central

    Kaneko, Yoshio

    2012-01-01

    Cognitive deficits in schizophrenia are pervasive, severe, and largely independent of the positive and negative symptoms of the illness. These deficits are increasingly considered to be core features of schizophrenia with evidence that the extent of cognitive impairment is the most salient predictor of daily functioning. Unfortunately, current schizophrenia treatment has been limited in addressing the cognitive deficits of the illness. Alterations in neuroplasticity are hypothesized to underpin these cognitive deficits, though preserved neuroplasticity may offer an avenue towards cognitive remediation. Key neuroplastic principles to consider in designing remediation interventions include ensuring sufficient intensity and duration of remediation programs, "bottom-up" training that proceeds from simple to complex cognitive processes, and individual tailoring of remediation regimens. We discuss several cognitive remediation programs, including cognitive enhancement therapy, which embrace these principles to target neurocognitive and social cognitive improvements and which havebeen demonstrated to be effective in schizophrenia. Future directions in cognitive remediation research include potential synergy with pharmacologic treatment, non-invasive stimulation techniques, and psychosocial interventions, identification of patient characteristics that predict outcome with cognitive remediation, and increasing the access to these interventions in front-line settings. PMID:23430145

  9. Unconventional cancer remedies.

    PubMed Central

    Danielson, K J; Stewart, D E; Lippert, G P

    1988-01-01

    Unproven and disproven remedies continue to abound for illnesses for which conventional treatment is only partially effective. This is particularly true with cancer, for which up to 50% of patients may be receiving unorthodox therapy. This article examines unconventional cancer remedies, their adverse effects, their common factors and the basis for their appeal, as well as what motivates and characterizes patients who choose these treatments. Also discussed is an approach that may be used by the conventional physician for patients who are likely to seek unorthodox treatment. This approach will help patients make the best decision about their treatment and protect them from the hazards of unconventional remedies. PMID:3285984

  10. Stabilization of positive charge on polytetrafluoroethylene electret films treated with titanium-tetrachloride vapor

    SciTech Connect

    Rychkov, Dmitry; Gerhard, Reimund

    2011-03-21

    The surface of polytetrafluoroethylene films was treated with titanium-tetrachloride vapor. The treatment was carried out in a flow reactor by means of molecular-layer deposition, a method from the arsenal of chemical nanotechnology. X-ray photoelectron spectroscopy reveals that such a treatment results in considerable changes in the chemical composition at and near the surface of the fluoropolymer film. Both, defluorination and oxidation of the surface were observed. At the same time, samples treated with titanium tetrachloride show a significant enhancement in the thermal stability of the positive homocharge. The thermally stimulated surface-potential-decay curves were observed to shift to higher temperatures by more than 100 deg. C

  11. Superfund Record of Decision (EPA Region 7): Hastings Ground Water Contamination FAR-MAR-CO subsite, Hastings Irrigation Pipe Company TCA Soils Operable Unit, Hastings, NE. (Second remedial action), September 1990

    SciTech Connect

    Not Available

    1990-09-28

    The Hastings Ground Water Contamination site (FAR-MAR-CO) is a contaminated aquifer in and near the city of Hastings, Adams County, Nebraska. The site consists of seven source areas, or subsites, contaminated with volatile industrial chemicals. The Record of Decision (ROD) addresses the Zone 2 portion of the FAR-MAR-CO subsite, which has been divided into two general areas of contamination referred to as Zone 1 and Zone 2. Zone 1, which includes grain elevators and areas to the north of the elevators, contains soil, soil-gas, and ground water contaminated with ethylene dibromide and carbon tetrachloride. Zone 1 contamination was addressed in a 1988 ROD. Zone 2, which is owned and operated by the Hastings Irrigation Pipe Company contains soil contamination primarily due to 1,1,1-trichloroethane (TCA) resulting from the disposal of cleaning solvents in Zone 2. Subsequent testing revealed that the concentration of TCA in Zone 2 had been reduced to a protective level. Response actions for ground water contamination near the FAR MAR CO subsite, however, will be addressed in subsequent remedial activities.

  12. Remediation; An overview

    SciTech Connect

    Bishop, J.

    1988-09-01

    The U.SD. government began committing the nation legally and financially in the last decade to the ultimate remediation of virtually all of the hazardous wastes that were produced in the past and remain to threaten human health and the environment, all that continue to be generated, and all that will be created in the future. Whether engendered by acts of God or human industry, the laws and regulations mandate, hazardous wastes and the threats they pose will be removed or rendered harmless. As mobilization for tackling the monumental task implied by those commitments has progressed, key concepts have changed in meaning. The remedy of remediation once literally meant burying our hazardous waste problems in landfills, for example, a solution now officially defined as the least desirable-although still commonly chosen - course of action. The process of identifying hazardous substances and determining in what quantities they constitute health and environmental hazards continues apace. As measurement technologies become increasingly precise and capable to detecting more 9s to the right of the decimal point, acceptable levels of emissions into the air and concentrations in the ground or water are reduced. This article is intended as a sketch of where the national commitment of remediation currently stands, with examples of implications for both generators of hazardous wastes and those who have entered-or seek to enter-the rapidly growing business of remediation.

  13. Remedial design/remedial action strategy report

    SciTech Connect

    Dieffenbacher, R.G.

    1994-06-30

    This draft Regulatory Compliance Strategy (RCS) report will aid the ER program in developing and implementing Remedial Design/Remedial Action (RD/RA) projects. The intent of the RCS is to provide guidance for the implementation of project management requirements and to allow the implementation of a flexible, graded approach to design requirements depending on the complexity, magnitude, schedule, risk, and cost for any project. The RCS provides a functional management-level guidance document for the identification, classification, and implementation of the managerial and regulatory aspects of an ER project. The RCS has been written from the perspective of the ER Design Manager and provides guidance for the overall management of design processes and elements. The RCS does not address the project engineering or specification level of detail. Topics such as project initiation, funding, or construction are presented only in the context in which these items are important as sources of information or necessary process elements that relate to the design project phases.

  14. Solutions Remediate Contaminated Groundwater

    NASA Technical Reports Server (NTRS)

    2010-01-01

    During the Apollo Program, NASA workers used chlorinated solvents to clean rocket engine components at launch sites. These solvents, known as dense non-aqueous phase liquids, had contaminated launch facilities to the point of near-irreparability. Dr. Jacqueline Quinn and Dr. Kathleen Brooks Loftin of Kennedy Space Center partnered with researchers from the University of Central Florida's chemistry and engineering programs to develop technology capable of remediating the area without great cost or further environmental damage. They called the new invention Emulsified Zero-Valent Iron (EZVI). The groundwater remediation compound is cleaning up polluted areas all around the world and is, to date, NASA's most licensed technology.

  15. Late preventive effects of trifluoperazine on carbon tetrachloride-induced hepatic necrosis

    SciTech Connect

    Villarruel, M.C.; Fernandez, G.; de Ferreyra, E.C.; de Fenos, O.M.; Castro, J.A.

    1986-04-01

    As a very preliminary test for a possible role of calmodulin in CCl/sub 4/-induced hepatic injury, we studied the effects of the anticalmodulin drug trifluoperazine (TFP) on several deleterious actions of CCl/sub 4/ on the liver. TFP administrated 30 min before or 6 or 10 hr after CCl/sub 4/ significantly prevented hepatic necrosis induced by the hepatotoxin at 24 hr but not at 72 hr. TFP did not modify the CCl/sub 4/ concentrations reaching the liver, or the intensity of the covalent binding of CCl/sub 4/-reactive metabolites to hepatic microsomal proteins or lipids or the CCl/sub 4/-induced cytochrome P-450 and glucose 6 phosphatase destruction. TFP administration decreased body temperature between 0 and 1 degree C in controls and between 1.2 and 3.5 degrees C in CCl/sub 4/-treated animals during the 24-hr observation period. When TFP-treated CCl/sub 4/-poisoned animals were kept normothermic, protective effects were eliminated. One possibility is that the protective effect of TFP might be due to a nonspecific action related to decreased body temperature. Alternatively, prevention might result from TFP inhibition of a late-occurring process critical for CCl/sub 4/-induced cell necrosis requiring calmodulin participation. If this alternative were in operation, protective consequences of this inhibitory effect of TFP should be either canceled or counteracted in the normothermic TFP + CCl/sub 4/-treated animal.

  16. Hepatoprotective activity of Haridradi ghrita on carbon tetrachloride-induced liver damage in rats.

    PubMed

    Satturwar, P M; Fulzele, S V; Joshi, S B; Dorle, A K

    2003-12-01

    Haridradi ghrita, a ghee based polyherbal formulation, (50, 100, 200 and 300 mg/kg) significantly lowered marker enzymes (SGPT, SGOT, ALP) and bilirubin in serum and liver peroxide, superoxide dismutase and catalase in liver homogenate following CCl4 (0.7 ml/kg, ip) toxicity. The protective effect was further supported by reversal of CCl4 induced histological changes. The results demonstrate significant hepatoprotective action of H. ghrita in CCl4 damaged rats. PMID:15320500

  17. Modulatory effect of Mangifera indica against carbon tetrachloride induced kidney damage in rats.

    PubMed

    Awodele, Olufunsho; Adeneye, Adejuwon Adewale; Aiyeola, Sheriff Aboyade; Benebo, Adokiye Senibo

    2015-12-01

    There is little scientific evidence on the local use of Mangifera indica in kidney diseases. This study investigated the reno-modulatory roles of the aqueous stem bark extract of Mangifera indica (MIASE) against CCl4-induced renal damage. Rats were treated intragastrically with 125, 250 and 500 mg/kg/day MIASE for 7 days before and after the administration of CCl4 (3 ml/kg of 30% CCl4, i.p.). Serum levels of electrolytes (Na+, K+, Cl(-), HCO3(-)), urea and creatinine were determined. Renal tissue reduced glutathione (GSH), malondialdehyde (MDA), catalase (CAT), superoxide (SOD) activities were also assessed. The histopathological changes in kidneys were determined using standard methods. In CCl4 treated rats the results showed significant (p<0.05) increases in serum Na+, K+, Cl(-), urea and creatinine. CCl4 also caused significant (p<0.05) decreases in renal tissue SOD, CAT and GSH and significant (p<0.05) increases in MDA. The oral MIASE treatment (125-500 mg/kg) was found to significantly (p<0.05) attenuate the increase in serum electrolytes, urea and creatinine. Similarly, MIASE significantly (p<0.05) attenuated the decrease in SOD, CAT and GSH levels and correspondingly attenuated increases in MDA. Mangifera indica may present a great prospect for drug development in the management of kidney disease with lipid peroxidation as its etiology. PMID:27486379

  18. Real-time analysis of breath for carbon tetrachloride and its metabolites

    SciTech Connect

    Kenny, D.V.; Callahan, P.J.; Thrall, K.D.

    1995-12-31

    Real-time breath analysis offers a non-invasive method to detect exposure to toxic air pollutants. Breath measurements are useful in environmental exposure studies, and may provide evidence about previous long-term or repeated exposures in environments that are not easy to monitor. If breath samples are collected during or immediately following a short term exposure, breath measurements can be used to predict the peak exposure. Previous breath sampling methodologies have been to collect repeated 1-minute breath samples at 5 minute intervals. Although this method can aid in describing the rapid exponential emptying of the blood compartment that occurs following peak exposure, sampling 5 minute intervals still forces an approximation of the true shape of the clearance kinetics. The authors have developed a methodology to quantitively measure the concentration of exhaled volatile compounds in real-time using laboratory rats. Continuously monitoring breath for a parent toxicant and its metabolite(s) provides input into physiologically based pharmacokinetic (PBPK) models to describe the bio-kinetics of a chemical in the body. Real-time analyses are better than batch sampling methods because of the rapidly changing kinetics of elimination of some volatile chemicals from the body.

  19. Hepatoprotective potential of Aloe barbadensis Mill. against carbon tetrachloride induced hepatotoxicity.

    PubMed

    Chandan, B K; Saxena, A K; Shukla, Sangeeta; Sharma, Neelam; Gupta, D K; Suri, K A; Suri, Jyotsna; Bhadauria, M; Singh, B

    2007-05-22

    Aloe barbadensis Mill. Syn. Aloe vera Tourn. ex Linn.(Liliaceae) has been used in variety of diseases in traditional Indian system of medicine in India and its use for hepatic ailments is also documented. In the present study an attempt has been made to validate its hepatoprotective activity. The shade dried aerial parts of Aloe barbadensis were extracted with petroleum ether (AB-1), chloroform (AB-2) and methanol (AB-3). The plant marc was extracted with distilled water (AB-4). All the extracts were evaluated for hepatoprotective activity on limited test models as hexobarbitone sleep time, zoxazolamine paralysis time and marker biochemical parameters. AB-1 and AB-2 were observed to be devoid of any hepatoprotective activity. Out of two active extracts (AB-3 and AB-4), the most active AB-4 was studied in detail. AB-4 showed significant hepatoprotective activity against CCl4 induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. Hepatoprotective potential was confirmed by the restoration of lipid peroxidation, glutathione, glucose-6-phosphatase and microsomal aniline hydroxylase and amidopyrine N-demethylase towards near normal. Histopathology of the liver tissue further supports the biochemical findings confirming the hepatoprotective potential of AB-4. The present study shows that the aqueous extract of Aloe barbadensis is significantly capable of restoring integrity of hepatocytes indicated by improvement in physiological parameters, excretory capacity (BSP retention) of hepatocytes and also by stimulation of bile flow secretion. AB-4 did not show any sign of toxicity up to oral dose of 2 g/kg in mice.

  20. Hepatoprotective activity of Calotropis gigantea flowers against carbon-tetrachloride-induced liver damage in mice.

    PubMed

    Ingawale, Deepa Krushna; Mandlik, Satish Karbhari; Kshirsagar, Ajay Digambar

    2013-07-23

    Ethanol extract of Calotropis gigantea flowers (CGFE) was evaluated for its antioxidant and hepatoprotective activity to validate its use in traditional therapeutic indications. This CGFE exhibited significant antioxidant activity (at 20, 40, 60, 80 and 100 µg/ml in vitro) as evidenced by its hydroxyl, nitric oxide and hydrogen peroxide anion radical scavenging activities. This in vitro antioxidant activity was reinforced by a significant hepatoprotection (at 250 and 500 mg/kg dose) by decreasing the activity of serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase. The hepatoprotective activity of the CGFE was comparable with standard drug silymarin (100 mg/kg, p.o.).The results obtained from present study indicate the presence of natural antioxidants and hepatoprotective constituents. Hence, the above finding confirms in vitro antioxidant and hepatoprotective potential of CGFE in mice.

  1. Carbon Tetrachloride and Chloroform Partition Coefficients Derived from Aqueous Desorption of Contaminated Hanford Sediments

    SciTech Connect

    Riley, Robert G.; Sklarew, Debbie S.; Brown, Christopher F.; Gent, Philip M.; Szecsody, Jim E.; Mitroshkov, Alexandre V.; Thompson, Christopher J.

    2005-07-08

    Researchers at PNNL determined CCl4 and CHCl3 groundwater/sediment partition coefficients (Kd values) for contaminated aquifer sediments collected from borehole C3246 (299-W15-46) located in the 200 West Area adjacent to the Z-9 trench. Having realistic values for this parameter is critical to predict future movement of CCl4 in groundwater from the 200 West Area.

  2. [Antimutagenic action of alpha-tocopherol acetate in carbon tetrachloride poisoning in animals].

    PubMed

    Maganova, N B; Stasenkova, K P; Bondarev, G I

    1982-01-01

    Additional administration of alpha-tocopherol acetate to S57Bl/6 mice and Wistar rats exposed to oral CCl4 under acute and subacute experimental conditions produced no appreciable effect on the frequency of cells with chromosomal aberrations. Additional administration of alpha-tocopherol acetate to S57Bl/6 mice exposed to CCl4 inhalation significantly lessened the frequency of somatic cells with chromosomal aberrations and the frequency of dominant lethals in sexual cells. This attests to a protective action of alpha-tocopherol acetate and confirms the data obtained by other research workers.

  3. Hepatoprotective effects of fermented Curcuma longa L. on carbon tetrachloride-induced oxidative stress in rats.

    PubMed

    Kim, Yongjae; You, Yanghee; Yoon, Ho-Geun; Lee, Yoo-Hyun; Kim, Kyungmi; Lee, Jeongmin; Kim, Min Soo; Kim, Jong-Choon; Jun, Woojin

    2014-05-15

    The hepatoprotective effect of fermented Curcuma longa L. (FC) was investigated in rats under CCl4-induced oxidative stress. FC at a dose of 30 or 300 mg/kg body weight (b.w.) was orally administered for 14 days followed by a single dose of CCl4 (1.25 mL/kg b.w. in 20% corn oil) on day 14. Pretreatment with FC drastically prevented the elevated activities of serum AST, ALT, LDH, and ALP caused by CCl4-induced hepatotoxicity. Histopathologically evident hepatic necrosis was significantly ameliorated by FC pretreatment. When compared to the CCl4-alone treated group, rats pretreated with FC displayed the reduced level of malondialdehyde. Furthermore, FC enhanced antioxidant capacities with higher activities of catalase, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase, and level of reduced glutathione. These results suggest that FC could be a candidate used for the prevention against various liver diseases induced by oxidative stress via elevating antioxidative potentials and decreasing lipid peroxidation.

  4. Modulatory effect of Mangifera indica against carbon tetrachloride induced kidney damage in rats

    PubMed Central

    Adeneye, Adejuwon Adewale; Aiyeola, Sheriff Aboyade; Benebo, Adokiye Senibo

    2015-01-01

    There is little scientific evidence on the local use of Mangifera indica in kidney diseases. This study investigated the reno-modulatory roles of the aqueous stem bark extract of Mangifera indica (MIASE) against CCl4-induced renal damage. Rats were treated intragastrically with 125, 250 and 500 mg/kg/day MIASE for 7 days before and after the administration of CCl4 (3 ml/kg of 30% CCl4, i.p.). Serum levels of electrolytes (Na+, K+, Cl−, HCO3−), urea and creatinine were determined. Renal tissue reduced glutathione (GSH), malondialdehyde (MDA), catalase (CAT), superoxide (SOD) activities were also assessed. The histopathological changes in kidneys were determined using standard methods. In CCl4 treated rats the results showed significant (p<0.05) increases in serum Na+, K+, Cl−, urea and creatinine. CCl4 also caused significant (p<0.05) decreases in renal tissue SOD, CAT and GSH and significant (p<0.05) increases in MDA. The oral MIASE treatment (125-500 mg/kg) was found to significantly (p<0.05) attenuate the increase in serum electrolytes, urea and creatinine. Similarly, MIASE significantly (p<0.05) attenuated the decrease in SOD, CAT and GSH levels and correspondingly attenuated increases in MDA. Mangifera indica may present a great prospect for drug development in the management of kidney disease with lipid peroxidation as its etiology. PMID:27486379

  5. PHOSGENE FORMATION FROM ADSORPTION OF CARBON TETRACHLORIDE ON OXYGEN MODIFIED IR(111). (R828598C802)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. Potentiation of carbon tetrachloride hepatotoxicity and lethality in type 2 diabetic rats.

    PubMed

    Sawant, Sharmilee P; Dnyanmote, Ankur V; Shankar, Kartik; Limaye, Pallavi B; Latendresse, John R; Mehendale, Harihara M

    2004-02-01

    There is a need for well characterized and economical type 2 diabetic model that mimics the human disease. We have developed a type 2 diabetes rat model that closely resembles the diabetic patients and takes only 24 days to develop robust diabetes. Nonlethal doses of allyl alcohol (35 mg/kg i.p.), CCl(4) (2 ml/kg i.p.), or thioacetamide (300 mg/kg i.p.) yielded 80 to 100% mortality in diabetic rats. The objective of the present study was to investigate two hypotheses: higher CCl(4) bioactivation and/or inhibited compensatory tissue repair were the underlying mechanisms for increased CCl(4) hepatotoxicity in diabetic rats. Diabetes was induced by feeding high fat diet followed by a single dose of streptozotocin on day 14 (45 mg/kg i.p.) and was confirmed on day 24 by hyperglycemia, normoinsulinemia, and oral glucose intolerance. Time course studies (0-96 h) of CCl(4) (2 ml/kg i.p.) indicated that although initial liver injury was the same in nondiabetic and diabetic rats, it progressed only in the latter, culminating in hepatic failure, and death. Hepatomicrosomal CYP2E1 protein and activity, lipid peroxidation, glutathione, and (14)CCl(4) covalent binding to liver tissue were the same in both groups, suggesting that higher bioactivation-based injury is not the mechanism. Inhibited tissue repair resulted in progression of injury and death in diabetic rats, whereas in the nondiabetic rats robust tissue repair resulted in regression of injury and survival after CCl(4) administration. These studies show high sensitivity of type 2 diabetes to model hepatotoxicants and suggest that CCl(4) hepatotoxicity is potentiated due to inhibited tissue repair. PMID:14610242

  7. Potentiation of carbon tetrachloride hepatotoxicity and lethality in type 2 diabetic rats.

    PubMed

    Sawant, Sharmilee P; Dnyanmote, Ankur V; Shankar, Kartik; Limaye, Pallavi B; Latendresse, John R; Mehendale, Harihara M

    2004-02-01

    There is a need for well characterized and economical type 2 diabetic model that mimics the human disease. We have developed a type 2 diabetes rat model that closely resembles the diabetic patients and takes only 24 days to develop robust diabetes. Nonlethal doses of allyl alcohol (35 mg/kg i.p.), CCl(4) (2 ml/kg i.p.), or thioacetamide (300 mg/kg i.p.) yielded 80 to 100% mortality in diabetic rats. The objective of the present study was to investigate two hypotheses: higher CCl(4) bioactivation and/or inhibited compensatory tissue repair were the underlying mechanisms for increased CCl(4) hepatotoxicity in diabetic rats. Diabetes was induced by feeding high fat diet followed by a single dose of streptozotocin on day 14 (45 mg/kg i.p.) and was confirmed on day 24 by hyperglycemia, normoinsulinemia, and oral glucose intolerance. Time course studies (0-96 h) of CCl(4) (2 ml/kg i.p.) indicated that although initial liver injury was the same in nondiabetic and diabetic rats, it progressed only in the latter, culminating in hepatic failure, and death. Hepatomicrosomal CYP2E1 protein and activity, lipid peroxidation, glutathione, and (14)CCl(4) covalent binding to liver tissue were the same in both groups, suggesting that higher bioactivation-based injury is not the mechanism. Inhibited tissue repair resulted in progression of injury and death in diabetic rats, whereas in the nondiabetic rats robust tissue repair resulted in regression of injury and survival after CCl(4) administration. These studies show high sensitivity of type 2 diabetes to model hepatotoxicants and suggest that CCl(4) hepatotoxicity is potentiated due to inhibited tissue repair.

  8. Frequency of OH in solutions of n-butanol in carbon tetrachloride: effect of dilution

    NASA Astrophysics Data System (ADS)

    Srivastava, P. K.; Rai, D. K.; Rai, S. B.

    2000-06-01

    It is noted that the 1←0 transition for νOH shows a blue shift as the relative concentration of n-butanol in a CCl 4- n-butanol is reduced. The magnitude of the shift decreases for the 2←0 transition and there is almost no shift for the 3←0 transition. These observations are consistent with the observed red shift [Y. Mizugai, F. Takimoto, M. Katayama, Chem. Phys. Lett. 76 (1980) 615] on dilution for the 5←0 transition in n-butanol. The observations have been interpreted on the basis of formation of O-H. . . . Cl hydrogen bond.

  9. Composition of concentrates of heterocyclic petroleum compounds isolated by complexformation with titanium tetrachloride

    SciTech Connect

    Nesterenko, V.I.; Alekseyev, A.P.; Plyusnin, A.N.

    1983-01-01

    The group composition of nitrous bases and aromatic sulphur compounds isolated by complex-formation with titanium tetrachloride from Soviet and West Siberian (Fedorov) crude oils was studied. Homologous series of nitrous bases are characterized by practically identical compounds ranging from C /SUB n/ H /SUB 2n-5/ N to C /SUB n/ H /SUB 2n-21/ N. Pyridine and quinoline derivatives with alkyl substituents and naphthene rings predominate. Thiacycloparaffins with a number of naphthene rings in the molecule of 1 to 5 predominate among saturated sulphur compounds. Unsaturated sulphur compounds are represented mainly by homologues of thiophene, benzo- and dibenzothiophene.

  10. Modularizing Remedial Mathematics

    ERIC Educational Resources Information Center

    Wong, Aaron

    2013-01-01

    As remedial mathematics education has become an increasingly important topic of conversation in higher education. Mathematics departments have been put under increased pressure to change their programs to increase the student success rate. A number of models have been introduced over the last decade that represent a wide range of new ideas and…

  11. COST OF MTBE REMEDIATION

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these cost, cost information for 311 sites was furnished by U.S. EPA Office of Undergr...

  12. 2014 Ohio Remediation Report

    ERIC Educational Resources Information Center

    Ohio Board of Regents, 2014

    2014-01-01

    In fulfillment of Ohio Revised Code 3333.041 (A) (1) the Chancellor has published a listing by school district of the number of the 2013 high school graduates who attended a state institution of higher education in academic year 2013-2014 and the percentage of each district's graduates required by the institution to enroll in a remedial course in…

  13. [Cognitive remediation and nursing care].

    PubMed

    Schenin-King, Palmyre; Thomas, Fanny; Braha-Zeitoun, Sonia; Bouaziz, Noomane; Januel, Dominique

    2016-01-01

    Therapies based on cognitive remediation integrate psychiatric care. Cognitive remediation helps to ease cognitive disorders and enable patients to improve their day-to-day lives. It is essential to complete nurses' training in this field. This article presents the example of a patient with schizophrenia who followed the Cognitive Remediation Therapy programme, enabling him to access mainstream employment. PMID:27615702

  14. Preparation and characterization of novel polytitanium tetrachloride coagulant for water purification.

    PubMed

    Zhao, Y X; Phuntsho, S; Gao, B Y; Huang, X; Qi, Q B; Yue, Q Y; Wang, Y; Kim, J-H; Shon, H K

    2013-11-19

    Polymeric metal coagulants are increasingly being used to improve coagulation efficiency, yet the research on the development of titanium and particularly polytitanium salts remains limited. This study is the first attempt in the synthesis, characterization, and application of polytitanium salts as coagulants. Polytitanium tetrachloride (PTC) solutions with different basicity values B (OH/Ti molar ratio) were prepared using a slow alkaline titration method. Jar tests were conducted to assess coagulation performance using both synthetic and real raw water samples, and the floc characteristics were monitored online using a laser diffraction particle size analyzer. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) was utilized to identify various Ti species, with the results providing strong evidence of the presence of various hydrolyzed Ti species in the titanium aqueous phase. Compared to titanium tetrachloride (TiCl4), higher or comparable turbidity and organic matter removal efficiency could be achieved by PTC with improved floc characteristics in terms of size, growth rate, and structure. Besides, the water pH after PTC coagulation was significantly improved toward neutral pH. This study indicates that PTC is an effective and promising coagulant for water purification. Besides, the PTC flocculated sludge was able to recycle and produce functional TiO2 photocatalyst.

  15. Remediation technologies for contaminated sediments

    SciTech Connect

    Swanson, L.M.

    1995-09-01

    Although soil and groundwater remediation has been conducted for many years, sediment remediation is still in its infancy. Regulatory agencies are now beginning to identify areas where contaminated sediments exist and evaluate their environmental impact. As these evaluations are completed, the projects must shift focus to how these sediments can be remediated. Also as the criteria for aquatic disposal of dredged sediments become more stringent, remediation technologies must be developed to address contaminated sediments generated by maintenance dredging.This report describes the various issues and possible technologies for sediment remediation.

  16. Remediation Technology Collaboration Development

    NASA Technical Reports Server (NTRS)

    Mahoney, John; Olsen, Wade

    2010-01-01

    This slide presentation reviews programs at NASA aimed at development at Remediation Technology development for removal of environmental pollutants from NASA sites. This is challenging because there are many sites with different environments, and various jurisdictions and regulations. There are also multiple contaminants. There must be different approaches based on location and type of contamination. There are other challenges: such as costs, increased need for resources and the amount of resources available, and a regulatory environment that is increasing.

  17. Remediating munitions contaminated soils

    SciTech Connect

    Shea, P.J.; Comfort, S.D.

    1995-10-01

    The former Nebraska Ordnance Plant (NOP) at Mead, NE was a military loading, assembling, and packing facility that produced bombs, boosters and shells during World War II and the Korean War (1942-1945, 1950-1956). Ordnances were loaded with 2,4,6-trinitrotoluene (TNT), amatol (TNT and NH{sub 4}NO{sub 3}), tritonal (TNT and Al) and Composition B (hexahydro-1,3,5-trinitro-1,3,5-triazine [RDX] and TNT). Process waste waters were discharged into wash pits and drainage ditches. Soils within and surrounding these areas are contaminated with TNT, RDX and related compounds. A continuous core to 300 cm depth obtained from an NOP drainage ditch revealed high concentrations of TNT in the soil profile and substantial amounts of monoamino reduction products, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT). Surface soil contained TNT in excess of 5000 mg kg{sup -1} and is believed to contain solid phase TNT. This is supported by measuring soil solution concentrations at various soil to solution ratios (1:2 to 1:9) and obtaining similar TNT concentrations (43 and 80 mg L{sup -1}). Remediating munitions-contaminated soil at the NOP and elsewhere is of vital interest since many of the contaminants are carcinogenic, mutagenic or otherwise toxic to humans and the environment. Incineration, the most demonstrated remediation technology for munitions-containing soils, is costly and often unacceptable to the public. Chemical and biological remediation offer potentially cost-effective and more environmentally acceptable alternatives. Our research objectives are to: (a) characterize the processes affecting the transport and fate of munitions in highly contaminated soil; (b) identify effective chemical and biological treatments to degrade and detoxify residues; and (c) integrate these approaches for effective and practical remediation of soil contaminated with TNT, RDX, and other munitions residues.

  18. Remediating MGP brownfields

    SciTech Connect

    Larsen, B.R.

    1997-05-01

    Before natural gas pipelines became widespread in this country, gas fuel was produced locally in more than 5,000 manufactured gas plants (MGPs). The toxic wastes from these processes often were disposed onsite and have since seeped into the surrounding soil and groundwater. Although the MGPs--commonly called gas plants, gas-works or town gas plants--have closed and most have been demolished, they have left a legacy of environmental contamination. At many MGP sites, underground storage tanks were constructed of wood or brick, with process piping and equipment which frequently leaked. Waste materials often were disposed onsite. Releases of coal tars, oils and condensates produced within the plants contributed to a wide range of contamination from polycyclic aromatic hydrocarbons, phenols, benzene and cyanide. Remediation of selected MGP sites has been sporadic. Unless the site has been identified as a Comprehensive Environmental Response, Compensation and Liability Information System (CERCLIS) Superfund site, the regulatory initiative to remediate often remains with the state in which the MGP is located. A number of factors are working to change that picture and to create a renewed interest in MGP site remediation. The recent Brownfield Initiative by the US Environmental Protection Agency (EPA) is such an example.

  19. Remedial Action Assessment System

    1997-02-01

    RAAS1.1 is a software-based system designed to assist remediation professionals at each stage of the environmental analysis process. RAAS1.1 provides a template for environmental restoration analysis, and provides the user with key results at each step in the analysis. RAAS1.1 assists the user to develop a coherent and consistent site description, estimate baseline and residual risk to public health from the contaminated site, identify applicable environmental restoration technologies, and formulate feasible remedial response alternatives. Inmore » addition, the RAAS1.1 methodology allows the user to then assess and compare those remedial response alternatives across EPA criteria, including: compliance with objectives; short-term and long-term effectiveness; extent of treatment; and implementability of the technologies. The analytic methodology is segmented and presented in a standardized, concise, easy-to-use format that can be viewed on the personal computer screen, saved and further manipulated, or printed for later use. Each screen and analytic step is accessed via a user-friendly personal computer graphical interface. Intuitively-designed buttons, menus, and lists help the user focus in on the particular information and analysis component of interest; the corresponding results are presented in a format that facilitates their use in decision-making.« less

  20. Spill behaviour using REACTPOOL. Part II. Results for accidental releases of silicon tetrachloride (SiCl(4)).

    PubMed

    Kapias, T; Griffiths, R F; Stefanidis, C

    2001-02-16

    Silicon tetrachloride is a toxic, corrosive water reactive substance that is used widely in the process industries. On spillage from containment it creates liquid pools that can either boil or evaporate. The main feature of the pool behaviour is the exothermic reaction with water. There are three sources of water available for reaction: free ground water, substrate water and atmospheric moisture. Hydrogen chloride gas and ortho-silicic acid solid (or silica gel) are produced by the hydrolysis reaction. The purpose of this paper is to describe the dangers involved in cases of accidental releases of silicon tetrachloride, to report its properties, referring to toxicity data, major accidents and mitigation tests. It also describes pool behaviour using REACTPOOL [1]. Model results indicate that the pool behaviour is governed mainly by the amount of water available for reaction. Surface roughness and wind speed also have a significant effect on the results. Results are compared with those for other water reactive chemicals in Part III of this series of papers [3]. The generated cloud will initially contain silicon tetrachloride and hydrogen chloride with numerous processes taking place. Although silicon tetrachloride has been involved in many major hazard incidents, there are no experimental data relevant to the modelling requirements. PMID:11163688

  1. Integrated in-situ remediation

    SciTech Connect

    Fustos, V.; Lieberman, P.

    1996-01-01

    This article presents an integrated approach to ex-situ and in-situ remediation. A sequence of processes, used successfully in their own right, but used synergistically in this approach, have achieved short-term, economic remediation. In addition the range of contaminants that can be treated is extended. The Process uses ozone, compressed oxygen, water vapor, heat, bioaugmentation and vapor extraction to remediate lower molecular weight hydrocarbons and higher molecular weight hydrocarbons. 3 figs.

  2. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    SciTech Connect

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  3. Electrokinetic remediation prefield test methods

    NASA Technical Reports Server (NTRS)

    Hodko, Dalibor (Inventor)

    2000-01-01

    Methods for determining the parameters critical in designing an electrokinetic soil remediation process including electrode well spacing, operating current/voltage, electroosmotic flow rate, electrode well wall design, and amount of buffering or neutralizing solution needed in the electrode wells at operating conditions are disclosed These methods are preferably performed prior to initiating a full scale electrokinetic remediation process in order to obtain efficient remediation of the contaminants.

  4. ABIOTIC DEGRADATION OF TRICHLOROETHYLENE UNDER THERMAL REMEDIATION CONDITIONS

    EPA Science Inventory

    The degradation of TCE (C2HCl3) to carbon dioxide (CO2) and chloride (Cl-) has been reported to occur during thermal remediation of subsurface environments. The overall goal of this study was to evaluate abiotic degradation of TCE at el...

  5. Remediating soils: Designing biochars to meet the need

    EPA Science Inventory

    Biochar, the porous, carbon-rich product of pyrolysis, may provide an additional tool for remediating both metal and organic contaminated soils and for reducing other soil limitations. Soils contaminated with metals, organics or limited in some other way is a world-wide problem...

  6. Saxton soil remediation project

    SciTech Connect

    Holmes, R.D.

    1995-12-31

    The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described.

  7. Rehabbing for remediation

    SciTech Connect

    Banton, D.; Anderson, R. )

    1994-03-01

    This article examines how rehabilitating contaminated city water wells in Moses Lake, Wash. took care of the problem for less than half the price of conventional remediation techniques. Wells located in similar hydrogeology, often found in the Western and Plains states, may benefit from this approach. Moses Lake is located on the Columbia Plateau in central Washington. The wells are between 700 and 800 ft deep, cased through 100--200 ft of alluvium, and completed open holes stretch across multiple basalt flows of the Wanapum formation of the Columbia River basalt group.

  8. Avoiding costly remediation

    SciTech Connect

    Scheels, R.H.

    1997-10-01

    Some oil and gas pipeline operations require equipment with hydraulic or oil circulation systems. These are subject to oil leaks or spills due to equipment malfunctions as well as normal operation. The potential liability and actual remediation and shutdown costs helped create the need for more environmentally friendly hydraulic fluids. Mobil has developed readily biodegradable, virtually nontoxic hydraulic fluids, Mobil EAL 224H and Mobil EAL Syndrajoc Series oils (EAL stands for Environmental Awareness Lubricants). The first is vegetable oil-based, while the others are formulated from high viscosity-index synthetic ester base stocks. Both use virtually nontoxic additive packages. These hydraulic fluids are described.

  9. Glucocorticoid-remediable aldosteronism.

    PubMed

    Halperin, Florencia; Dluhy, Robert G

    2011-06-01

    Glucocorticoid-remediable aldosteronism (GRA) is a hereditary form of primary hyperaldosteronism and the most common monogenic cause of hypertension. A chimeric gene duplication leads to ectopic aldosterone synthase activity in the cortisol-producing zona fasciculata of the adrenal cortex, under the regulation of adrenocorticotropin (ACTH). Hypertension typically develops in childhood, and may be refractory to standard therapies. Hypokalemia is uncommon in the absence of treatment with diuretics. The discovery of the genetic basis of the disorder has permitted the development of accurate diagnostic testing. Glucocorticoid suppression of ACTH is the mainstay of treatment; alternative treatments include mineralocorticoid receptor antagonists.

  10. Synergistic neurotoxicity of carbon tetrachloride/carbon disulfide (80/20 fumigants) and other pesticides in grain storage workers.

    PubMed

    Peters, H A; Levine, R L; Matthews, C G; Sauter, S; Chapman, L

    1986-01-01

    Neurophysiologic, neurobehavioral, and neuropsychologic profiles in 17 grain storage workers, 1 grain inspector, and 4 malting laboratory workers are described. The effects of CS2 toxicity as seen in viscose rayon workers as well as in experimental animals is remarkably similar to the clinical profile of our grain storage workers. CS2 use explains the dysfunction of peripheral axons, auditory nerve, the optic nerve, and the extrapyramidal system, as well as altered behavior and cognition changes. The signs and symptoms in these workers seem to be dose-related and we note that workers separated out from the areas where fumigation took place reported improvement not seen by fellow workers who continued the fumigant treatment routine. Likewise, malting laboratory workers exposed only to the grain dust from 3 to 7 years showed only minimal symptoms. Though a number of mechanism have been suggested for the alteration of neuropsychological function, the chelating ability of DDC derived from CS2 and its ability to markedly increase copper and zinc within the central nervous system suggests a mechanism of toxicity analogous to copper intoxication as in Wilson's Disease and may explain the production of extrapyramidal symptoms in these patients. Chelation of copper might prove therapeutic in CS2 poisoning. It is obvious that both basic and clinical research will be necessary to sort out the questions raised. We applaud the EPA's decision to ban the use of 80/20 fumigants and also methyl bromide, and trust that similar toxic substances be carefully studied before their selection for replacing these previous toxic agents. We further decry the technique of re-introducing grain dust into the food chain rather than destroying it, since the dust contains very high residues of fumigant material. We speculate on the possible role of CS2 and other pesticides in the food chain and the incidence of Parkinsonian symptoms in these patients and the general public.

  11. Flexible remediation design lowers total cost

    SciTech Connect

    Struttman, T.; Towarnicky, J.

    1995-08-01

    Most groundwater remediation systems are built to operate for many years. Predicting time to cleanup is difficult due to unforeseeable problems and changes in underground conditions. As a result, many treatment systems tend to be over-designed, with multiple built-in safety factors and excessive capital costs. Total time in operation also is unnecessarily long because upfront assumptions often fail to match future realities. A Superfund site remediation in Arizona illustrates how a flexible, ongoing design approach can significantly reduce life cycle costs. The site is a municipal airport where degreasing activities from the 1940s through the 1970s left trichloroethylene (TCE) in the soil and in two aquifers beneath the site. The soil is being remediated in five areas, representing approximately 10 acres. The upper aquifer plume covers approximately 400 acres, and the two lower aquifer plumes cover 10 and 30 acres. The cleanup involves extraction of groundwater in a pump-and-treat system of 16 extraction wells, followed by treatment with an air stripper for the upper aquifer and liquid-phase high-pressure carbon on the lower aquifer. The treated/clean water is reinjected to augment hydraulic control.

  12. Remediating Remediation: From Basic Writing to Writing across the Curriculum

    ERIC Educational Resources Information Center

    Faulkner, Melissa

    2013-01-01

    This article challenges faculty members and administrators to rethink current definitions of remediation. First year college students are increasingly placed into basic writing courses due to a perceived inability to use English grammar correctly, but it must be acknowledged that all students will encounter the need for remediation as they attempt…

  13. Managing soil remediation problems.

    PubMed

    Okx, J P; Hordijk, L; Stein, A

    1996-12-01

    Soil remediation has only a short history but the problem addressed is a significant one. Cost estimates for the clean-up of contaminated sites in the European Union and the United States are in the order of magnitude of 1,400 billion ECU. Such an enormous operation deserves the best management it can get. Reliable cost estimations per contaminated site are an important prerequisite. This paper addresses the problems related to site-wise estimations.When solving soil remediation problems, we have to deal with a large number of scientific disciplines. Too often solutions are presented from the viewpoint of only one discipline. In order to benefit from the combined disciplinary knowledge and experience, we think that it is necessary to describe the interrelations between these disciplines. This can be realized by developing an adequate model of the desired process which enables to consider and evaluate the essential factors as interdependent components of the total system.The resulting model provides a binding paradigm to the contributing disciplines which will result in improved efficiency and effectivity of the decision and the cost estimation process. In the near future, we will release the "Biosparging and Bioventing Expert Support System", an expert support system for problem owners, consultants and authorities dealing with the design and operation of a biosparging and/or a bioventing system.

  14. Soil Remediation Test

    SciTech Connect

    Manlapig, D. M.; Williamsws

    2002-04-01

    Soils contaminated with petroleum by-products can now be effectively remediated using a variety of technologies. Among these are in-situ bioremediation, land farming, and landfill/replacing of soil. The range of efficiencies and cost effectiveness of these technologies has been well documented. Exsorbet Plus is showing promise as an in-situ bioremediation agent. It is made of naturally grown Spaghnum Peat Moss which has been activated for encapsulation and blended with nitrogen-rich fertilizer. In its initial field test in Caracas, Venezuela, it was able to remediate crude oil-contaminated soil in 90 days at less than half of the cost of competing technologies. Waste Solutions, Corp and the US Department of Energy signed a Cooperative Research and Development Agreement to test Exsorbet Plus at the Rocky Mountain Oilfield Testing Center near Casper, Wyoming. As part of the test, soil contaminated with crude oil was treated with Exsorbet Plus to aid the in-situ bioremediation process. Quantitative total petroleum hydrocarbon (TPH) measurements were acquired comparing the performance of Exsorbet Plus with an adjacent plot undergoing unaided in-situ bioremediation.

  15. Home Assessment and Remediation.

    PubMed

    Barnes, Charles S; Horner, W Elliott; Kennedy, Kevin; Grimes, Carl; Miller, J David

    2016-01-01

    Awareness of the relationship of fungi to asthma in indoor air is very old and well documented. There is substantial evidence that mold and dampness exacerbate asthma in sensitized individuals. Many governmental and nongovernmental organizations around the world have issued guidelines to the effect that the elimination of moisture intrusion and the removal of moldy items from living space can improve respiratory health. The process of home assessment for moisture and mold presence is discussed along with factors that can be used to guide fungal exposure reduction efforts. An approach to the assessment process itself is outlined, and common causes of moisture and mold damage are described. Points that should be included in a report resulting from a home assessment and rudimentary elements of report interpretation are discussed. Emphasis is that interpretation of sampling for moisture and fungal presence should be provided by the person performing the assessment. We conclude that multifaceted remediation contributes to fungal allergen avoidance. The use of an indoor environmental professional to generate evaluation reports and remediation activities can be a valuable contribution to an overall allergen avoidance strategy.

  16. Interpersonal Needs of Remedial Readers.

    ERIC Educational Resources Information Center

    Cochran, Judith

    A study sought to determine the effects of reading deficiency on the interpersonal relationship needs of regular and remedial readers as composite groups and on elementary and secondary school remedial and regular readers as age groups. Elementary and secondary school students were randomly selected and tested on the Gates-MacGinitie Reading Tests…

  17. Innovative Technologies for Chlorinated Solvent Remediation

    NASA Astrophysics Data System (ADS)

    Pennell, Kurt D.; Cápiro, Natalie L.

    2014-07-01

    The following sections are included: * INTRODUCTION * TRADITIONAL REMEDIATION TECHNOLOGIES (1980s) * RESEARCH AND DEVELOPMENT OF INNOVATIVE REMEDIATION TECHNOLOGIES (1990s-2000s) * CURRENT TRENDS IN CHLORINATED SOLVENT REMEDIATION (2010s) * CLOSING THOUGHTS * REFERENCES

  18. Sustainable Remediation for Enhanced NAPL Recovery from Groundwater

    NASA Astrophysics Data System (ADS)

    Javaher, M.

    2012-12-01

    Sustainable remediation relates to the achievement of balance between environmental, social, and economic elements throughout the remedial lifecycle. A significant contributor to this balance is the use of green and sustainable technologies which minimize environmental impacts, while maximizing social and economic benefits of remedial implementation. To this end, a patented mobile vapor energy generation (VEG) technology has been developed targeting variable applications, including onsite soil remediation for unrestricted reuse and enhanced non-aqueous phase liquid (NAPL) recover at the water table. At the core of the mobile VEG technology is a compact, high efficiency vapor generator, which utilizes recycled water and propane within an entirely enclosed system to generate steam as high as 1100°F. Operating within a fully enclosed system and capturing all heat that is generated within this portable system, the VEG technology eliminates all emissions to the atmosphere and yields an undetected carbon footprint with resulting carbon dioxide concentrations that are below ambient levels. Introduction of the steam to the subsurface via existing wells results in a desired change in the NAPL viscosity and the interfacial tension at the soil, water, NAPL interface; in turn, this results in mobilization and capture of the otherwise trapped, weathered NAPL. Approved by the California Air Resources Control Board (and underlying Air Quality Management Districts) and applied in California's San Joaquin Valley, in-well heating of NAPLs trapped at the water table using the VEG technology has proven as effective as electrical resistivity heating (ERH) in changing the viscosity of and mobilizing NAPLs in groundwater in support of recovery, but has achieved these results while minimizing the remedial carbon footprint by 90%, reducing energy use by 99%, and reducing remedial costs by more than 95%. NAPL recovery using VEG has also allowed for completion of source removal historically

  19. WATER AS A REAGENT FOR SOIL REMEDIATION

    SciTech Connect

    Indira S. Jayaweera; Jordi Diaz-Ferraro

    2000-02-28

    SRI International is conducting experiments to develop and evaluate hydrothermal extraction technology for remediating petroleum-contaminated soils. Most current remediation practices generally fail (or are cost prohibitive) to remove the polycyclic aromatic hydrocarbons (PAHs) found in petroleum-contaminated sites or they require the use of organic solvents to achieve removal, at the expense of additional contamination and with the added cost of recycling solvents. Hydrothermal extraction offers the promise of efficiently extracting PAHs and other kinds of organics from contaminated soils at moderate temperatures and pressures, using only water and inorganic salts such as carbonate. Initial work is being conducted at SRI to measure the solubility and rate of solubilization of selected PAHs (anthracene, fluoranthene, pyrene, and chrysene) in water, using SRI's hydrothermal optical cell with the addition of varying amounts of sodium carbonate to evaluate the efficiency of the technology for removing PAHs from the soil. Preliminary results with pyrene and fluoranthene in water clearly indicate a significant enhancement of solubility with increase in temperature. During this quarter, we conducted experiments with pyrene in the temperature range 200 to 300 C and observed a great enhancement in solubility with an increase in temperature. We also started experiments with real-world soil samples purchased from the subcontractor.

  20. Synthesis and oxidation of luminescent silicon nanocrystals from silicon tetrachloride by very high frequency nonthermal plasma

    NASA Astrophysics Data System (ADS)

    Gresback, Ryan; Nozaki, Tomohiro; Okazaki, Ken

    2011-07-01

    Silicon nanocrystals have recently attracted significant attention for applications in electronics, optoelectronics, and biological imaging due to their size-dependent optical and electronic properties. Here a method for synthesizing luminescent silicon nanocrystals from silicon tetrachloride with a nonthermal plasma is described. Silicon nanocrystals with mean diameters of 3-15 nm are synthesized and have a narrow size distribution with the standard deviation being less than 20% of the mean size. Control over crystallinity is achieved for plasma pressures of 1-12 Torr and hydrogen gas concentrations of 5-70% through adjustment of the plasma power. The size of nanocrystals, and resulting optical properties, is mainly dependent on the gas residence time in the plasma region. Additionally the surface of the nanocrystals is covered by both hydrogen and chlorine. Oxidation of the nanocrystals, which is found to follow the Cabrera-Mott mechanism under ambient conditions, is significantly faster than hydrogen terminated silicon due to partial termination of the nanocrystal surface by chlorine.

  1. Remediation of contaminated soils

    SciTech Connect

    Radhakrishnan, R.; Ariza, C.H.

    1997-07-01

    At least three types of zones of contamination exist whenever there is a chemical release. The impact of Non-Aqueous-Phase Liquids (NAPL) on soils and groundwater, together with the ultimate transport and migration of constituent chemicals in their dissolved or sorbed states, had led environmentalists to develop several techniques for cleaning a contaminated soil. Zone 1 represents the unsaturated zone which could be contaminated to retention capacity by both Dense Non-Aqueous-Phase Liquids (DNAPL) and Light Non-Aqueous-Phase Liquids (LNAPL). Zone 2 represents residual DNAPL or LNAPL contamination found below the groundwater table in the saturated zone. Zone 3 is represented by either the presence of NAPL dissolved in the aqueous phase, volatilized in the unsaturated zone or sorbed to either saturated or unsaturated soils. Cleanup of petroleum contaminated soils is presented in this paper. Among several techniques developed for this purpose, in-situ biological remediation is discussed in detail as a technique that does not involve excavation, thus, the costs and disruption of excavating soil are eliminated.

  2. ICDF Complex Remedial Action Report

    SciTech Connect

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  3. A Framework for Remediating Number Combination Deficits

    ERIC Educational Resources Information Center

    Fuchs, Lynn S.; Powell, Sarah R.; Seethaler, Pamela M.; Fuchs, Douglas; Hamlett, Carol L.; Cirino, Paul T.; Fletcher, Jack M.

    2010-01-01

    This article introduces a framework for the remediation of number combination (NC) deficits. Research on the remediation of NC deficits is summarized, and research program studies are used to illustrate the 3 approaches to remediation. The Framework comprises a 2-stage system of remediation. The less intensive stage implementing 1 of 3…

  4. Growth of crystals of several boron-carbon compositions by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Kevill, D. N.; Rissmann, T. J.; Brewe, D.; Wood, C.

    1986-01-01

    Boron-carbon compounds have been deposited by the flow of carbon tetrachloride and boron trichloride, in the presence of a large excess of hydrogen, over a graphite surface maintained at 1000-1300 C. Deposits were formed on either an RF-heated disc or a tube or insert heated by a resistance furnace. Crystalline materials ranging in composition from B2C to B17C have been obtained.

  5. WATER AS A REAGENT FOR SOIL REMEDIATION

    SciTech Connect

    Indira S. Jayaweera; Montserrat Marti-Perez; Jordi Diaz-Ferrero; Angel Sanjurjo

    2001-03-29

    SRI International is conducting experiments to develop and evaluate hydrothermal extraction technology or hot water extraction (HWE) technology for remediating petroleum-contaminated soils. Most current remediation practices either fail to remove the polycyclic aromatic hydrocarbons (PAHs) found in petroleum-contaminated sites, are too costly, or require the use of organic solvents at the expense of additional contamination and with the added cost of recycling solvents. Hydrothermal extraction offers the promise of efficiently extracting PAHs and other kinds of organics from contaminated soils at moderate temperatures and pressures, using only water and inorganic salts such as carbonate. SRI has conducted experiments to measure the solubility and rate of solubilization of selected PAHs (fluoranthene, pyrene, chrysene, 9,10-dimethylanthracene) in water using SRI's hydrothermal optical cell with the addition of varying amounts of sodium carbonate to evaluate the efficiency of the technology for removing PAHs from the soil. SRI data shows a very rapid increase in solubility of PAHs with increase in temperature in the range 25-275 C. SRI also measured the rate of solubilization, which is a key factor in determining the reactor parameters. SRI results for fluoranthene, pyrene, chrysene, and 9,10-dimethylanthracene show a linear relationship between rate of solubilization and equilibrium solubility. Also, we have found the rate of solubilization of pyrene at 275 C to be 6.5 ppm/s, indicating that the equilibrium solubilization will be reached in less than 3 min at 275 C; equilibrium solubility of pyrene at 275 C is 1000 ppm. Also, pyrene and fluoranthene appear to have higher solubilities in the presence of sodium carbonate. In addition to this study, SRI studied the rate of removal of selected PAHs from spiked samples under varying conditions (temperature, pore sizes, and pH). We have found a higher removal of PAHs in the presence of sodium carbonate in both sand and

  6. HANFORD GROUNDWATER REMEDIATION

    SciTech Connect

    CHARBONEAU, B; THOMPSON, M; WILDE, R.; FORD, B.; GERBER, M.S.

    2006-02-01

    united in its desire to protect the Columbia River and have a voice in Hanford's future. This paper presents the challenges, and then discusses the progress and efforts underway to reduce the risk posed by contaminated groundwater at Hanford. While Hanford groundwater is not a source of drinking water on or off the Site, there are possible near-shore impacts where it flows into the Columbia River. Therefore, this remediation is critical to the overall efforts to clean up the Site, as well as protect a natural resource.