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. Overcoming Barriers to the Remediation of Carbon Tetrachloride Through Manipulation of Competing Reaction Mechanisms

    SciTech Connect

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

    2004-03-29

    Most approaches that have been proposed for the remediation of groundwater contaminated with carbon tetrachloride produce chloroform as the major product and methylene chloride as a minor product. Both of these products are nearly as persistent and problematic as the parent compound, but competing reaction pathways produce the more desirable products carbon monoxide and/or formate. Branching between these reaction pathways is highly variable, but the controlling factors have not been identified. To improve the applicability of reductive remediation technologies to the large plumes of carbon tetrachloride at several DOE sites, we are pursuing the complete characterization of the mechanisms and kinetics of competing degradation reactions of carbon tetrachloride through laboratory experiments closely coordinated with theoretical modeling studies. The results are beginning to suggest strategies for maximizing the yield of desirable products from carbon tetrachloride degradation, which will be tested in column model systems using real site waters and matrix materials.

  3. 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

  4. Overcoming Barriers to the Remediation of Carbon Tetrachloride through Manipulation of Competing Reaction Mechanisms

    SciTech Connect

    Tratnyek, Paul G.; Amonette, James E.; Bylaska, Eric J. and Szecsody, James E.

    2004-06-01

    Most approaches that have been proposed for the remediation of groundwater contaminated with carbon tetrachloride (CCl4) produce chloroform (CHCl3) as the major product and methylene chloride (CH2Cl2) as a minor product. Both of these products are nearly as persistent and problematic as the parent compound, but competing reaction pathways produce the more desirable products carbon monoxide (CO) and/or formate (HCOO-). Results scattered throughout the chemical and environmental engineering literature show that the branching between these reaction pathways is highly variable, but the controlling factors have not been identified. If we understood the fundamental chemistry that controls the branching among these, and related, product-formation pathways, we could improve the applicability of a host of remediation technologies (both chemical and biological) to the large plumes of CCl4 that contaminate DOE sites across the country. This project will provide the first complete characterization of the mechanisms and kinetics of competing degradation reactions of CCl4 through laboratory experiments in simple model systems closely coordinated with theoretical modeling studies. The results provide strategies for maximizing the yield of desirable products from CCl4 degradation, and the most promising of these will be tested in column model systems using real site waters and matrix materials.

  5. Overcoming Barriers to the Remediation of Carbon Tetrachloride Through Manipulation of Competing Reaction Mechanisms

    SciTech Connect

    Tratnyek, Paul G.

    2003-06-01

    Quantify the kinetics of all competing product-formation pathways, over a range of conditions relevant to groundwater remediation, using well-mixed batch reactors and analysis primarily by chromatography. At OGI, batch experiments were conducted on Fe(0) systems (both Fisher Electrolytic and Nano-sized iron). The experiments were done with and without buffer. The buffered experiments tried to contrast two buffers: an organic buffer (EPPS, presumably a H atom donor), and the inorganic borate. In the buffered experiments, the pH was varied (7.3 and 8.4). For the pre-exposure treatment, after trying a variety of methods, like shaking and not shaking for varied amounts of time, it was decided to stick with not shaking and have a pre-exposure of 24 hours. The unbuffered data did not show any marked trend with increasing mass of Felc. However, 3.5 g of Fe showed about 100% conversion to CHCl3, and 1g of Fe showed 50% conversion. At pHs 8.4 and 7.3, there was no trend observed for branching ratios between EPPS and Borate buffer. kCT (disappearance rate constant of carbon tetrachloride) values were found to be different from CT and CF fits. Experiments with nano-iron (unbuffered, buffered with both buffers at pH 8.3), did not show any trend with respect to Fisher Iron, except for the unbuffered experiments, where the CF ''yield'' was less in the nano iron case. Future experiments involve testing for chloride, formate and CO, and performing experiments over a wider range of pH and buffers. Batch experiments were conducted at PNNL to compare the efficiency and product distribution of representative Fe(II) and Fe(0) systems applied to dechlorination of CCl4. These experiments involved (1) a smectite clay with Fe(III) in its structure that had been reduced to Fe(II) by dithionite treatment, (2) the same clay to which Fe(II) was added as an exchangeable cation, (3) electrolytic Fe(0) from Fisher, and (4) a mixture of the reduced clay and Fe(0). Experiments were conducted in

  6. 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....

  7. 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....

  8. 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....

  9. 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....

  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 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....

  12. 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....

  13. 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....

  14. 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....

  15. 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....

  16. 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.

  17. Carbon tetrachloride under extreme conditions.

    PubMed

    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 CCl4 were acquired up to 28 GPa. Evidence was observed for at least two new phases of CCl4 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 CCl4 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: CCl4+ hν → C + 2Cl2. PMID:24852546

  18. 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}.

  19. 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

  20. 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,…

  1. IMPROVED RISK ESTIMATES FOR CARBON TETRACHLORIDE

    EPA Science Inventory

    Carbon tetrachloride (CCl4) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. Costs associated with cleanup of CCl4 at DOE facilities are driven by current cancer risk estimates which assume CCl4 is a genotoxic carcinogen. However, a grow...

  2. 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.'

  3. 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.

  4. Recent Site-Wide Transport Modeling Related to the Carbon Tetrachloride Plume at the Hanford Site

    SciTech Connect

    Bergeron, Marcel P.; Cole, C R.

    2005-11-01

    Carbon tetrachloride transport in the unconfined aquifer system at the Hanford Site has been the subject of follow-on studies since the Carbon Tetrachloride Innovative Treatment Remediation Demonstration (ITRD) Program was completed in FY 2002. These scoping analyses were undertaken to provide support for strategic planning and guidance for the more robust modeling needed to obtain a final record of decision (ROD) for the carbon tetrachloride plume in the 200 West Area. This report documents the technical approach and the results of these follow-on, site-wide scale-modeling efforts. The existing site-wide groundwater model was used in this effort. The work extended that performed as part of the ITRD modeling study in which a 200 West Area scale submodel was developed to examine arrival concentrations at an arbitrary boundary between the 200 E and 200 W areas. These scoping analyses extended the analysis to predict the arrival of the carbon tetrachloride plume at the Columbia River. The results of these analyses illustrate the importance of developing field-scale estimates of natural attenuation parameters, abiotic degradation rate and soil/water equilibrium sorption coefficient, for carbon tetrachloride. With these parameters set to zero, carbon tetrachloride concentrations will exceed the compliance limit of 5 ?g/L outside the 200 Area Plateau Waste Management Area, and the aquifer source loading and area of the aquifer affected will continue to grow until arrival rates of carbon tetrachloride equal source release rates, estimated at 33 kg/yr. Results of this scoping analysis show that the natural attenuation parameters are critical in predicting the future movement of carbon tetrachloride from the 200 West Area. Results also show the significant change in predictions between continual source release from the vadose zone and complete source removal.

  5. 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....

  6. Carbon Tetrachloride Emissions from the Amazon Forest

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Chambers, J. Q.; Higuchi, N.; Jardine, A. B.; Martin, S. T.; Manzi, A. O.

    2014-12-01

    As a chemically inert greenhouse gas in the troposphere with lifetimes up to 50 years but active in ozone destruction in the stratosphere, carbon tetrachloride (CCl4) plays a major role in the atmospheric chlorine budget and is widely considered strictly of anthropogenic origin deriving from numerous industrial processes and products. However, satellite remote sensing studies have shown higher concentrations at the Equator, and earlier work has suggested possible biogenic sources. Here we present highly vertically-resolved atmospheric gradients of CCl4 within and above a primary rainforest ecosystem from three towers in the Central Amazon. The observed buildup of CCl4 mixing ratios near the top of the main canopies provides new evidence for a potentially large biogenic source from the Basin. By demonstrating the need to represent tropical forests as biogenic sources of CCl4, our study may help narrow the gap between remote sensing observations of CCl4 and emission, chemistry, and transport models and therefore lead to improved predictions of its role in atmospheric chemistry and climate.

  7. Resonance Raman spectroscopy of volatile organics -- Carbon tetrachloride

    SciTech Connect

    Barletta, R.E.; Veligdan, J.T.

    1994-09-01

    Volatile organic chemicals are a class of pollutants which are regulated at very low levels by the EPA. Consequently a need exists as a part of site remediation efforts within DOE to develop technologies which will allow for the in situ monitoring of these chemicals. Resonance Raman spectroscopy is a potential technique to accomplish this if the resonance enhancement is sufficiently high. Carbon tetrachloride was selected as a test case. Measurements under resonance conditions at 248 nm showed an enhancement factor of 2 {times} 10{sup 4}. Using this value an estimate of the sensitivity for both in situ and remote monitoring of CCl{sup 4} was made. It was concluded that resonance Raman could be used to detect these chemicals at levels of regulatory interest. Future effort directed towards the development of a suitable probe as well as a field-portable system would be desirable. Such effort could be directed towards the solution of a particular monitoring problem within a DOE waste remediation project. Once developed, however, it should be easily generalized to the analysis of other VOC`s in other environments.

  8. 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

  9. 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. PMID:25912910

  10. Evidence for Localization of Reaction Upon Reduction of Carbon Tetrachloride by Granular Iron

    SciTech Connect

    Gaspar, Daniel J.; Lea, Alan S.; Engelhard, Mark H.; Baer, Donald R.; Miehr, R.; Tratnyek, Paul G.

    2002-10-01

    The distribution of reaction sites on iron particles exposed to water containing carbon tetrachloride has been examined by measuring the locations of reaction products. The uniformity or localization of reaction sites has implications for understanding and modeling the reduction of environmental contaminants by iron in ground water systems. Granular iron surfaces similar to those being used for environmental remediation applications were studied using surfaces analysis techniques to develop an understanding of the physical and chemical structure of the surface and oxide films. Scanning Auger microscopy and imaging time-of-flight secondary ion mass spectrometry revealed that granular iron exposed to carbon tetrachloride-saturated water exhibits chloride-enriched regions occurred at pits rather than on the passive oxide film on the metal. Understanding the nature of the local solute reduction sites will play an important role in modeling the kinetics of reaction at passive iron oxide films in environmental systems.

  11. 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...

  12. 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...

  13. ABIOTIC TRANSFORMATION OF CARBON TETRACHLORIDE AT MINERAL SURFACES

    EPA Science Inventory

    Transformation of carbon tetrachloride (CCl4) by biotite, vermiculite, and pyrite in the presence of hydrogen sulfide (HS-) was studied under different environmental conditions. n systems containing biotite and vermiculite, the rate of CC4 transformation was dependent on the temp...

  14. IN-SITU BIOTRANSFORMATION OF CARBON TETRACHLORIDE UNDER ANOXIC CONDITIONS

    EPA Science Inventory

    This field and laboratory project evaluated the possibility of stimulating a native bacterial population to biotransform carbon tetrachloride (CT) under anoxic conditions. In addition,the transformation of 1,1,1-trichloroethane (TCA), Freon-11, and Freon-113 present as background...

  15. 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.

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

    SciTech Connect

    Alvarado, J. S.; Rose, C.; LaFreniere, L.; Environmental Science Division

    2010-01-01

    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.

  17. In situ bioremediation for the Hanford carbon tetrachloride plume. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-04-01

    The 200 Area at Hanford (also called the Central Plateau) contains approximately 817 waste sites, 44 facilities to be demolished, and billions of gallons of contaminated groundwater resulting from chemical processing plants and associated waste facilities (e.g., waste tanks). From 1955 to 1973, carbon tetrachloride, nitrate, and other materials were discharged to subsurface liquid waste disposal facilities in the 200 Area. As much as 600,000 kilograms of carbon tetrachloride may have entered the soil column and a portion of this has contaminated the underlying aquifer. In Situ Bioremediation for the Hanford Carbon Tetrachloride Plume (ISB), which is the term used in this report for an in situ treatment process using indigenous micro-organisms with a computer based Accelerated Bioremediation Design Tool (ABDT), remediates groundwater contaminated with volatile organic compounds (VOCs) and nitrates under anaerobic conditions. ISB involves the injection of nutrients into the groundwater and subsequent extraction and re-injection of the groundwater to provide nutrient distribution in the aquifer.

  18. Scalable Modeling of Carbon Tetrachloride Migration at the Hanford Site Using the STOMP Simulator

    SciTech Connect

    White, Mark D.; Oostrom, Mart; Rockhold, Mark L.; Rosing, Matthew

    2008-05-01

    Numerical simulation has been applied in support of the U.S. Department of Energy’s (DOE’s) efforts to characterize the nature and distribution of carbon tetrachloride in the deep vadose zone at the Hanford site, near Richland, Washington. Three-dimensional computational domains were used, with layered and heterogeneous distributions of soil properties, in this numerical investigation into the vertical and lateral distribution of carbon tetrachloride beneath it release point (216-Z-9 trench) and the effects of soil vapor extraction process. The complexity of the modeled physical processes, namely, the nonlinearities associated with multifluid subsurface flow, including phase transitions and hysteresis in the relative permeability-saturation-capillary pressure functions, limits the grid resolution when executed using single processor computers. To achieve higher grid resolutions and acceptable detail in the subsurface distribution and remediation of carbon tetrachloride, execution on multiple processors was required. This paper describes and demonstrates a scalable implementation of a multifluid subsurface flow and transport with capabilities for volatile organic compounds, residual nonaqueous phase liquid formation in the vadose zone, and soil vapor extraction, using multiple wells. Developing scientific software for execution on parallel computers has unique challenges. The guiding objectives for developing this scalable code were to keep the source coding readable and modifiable by subsurface scientists, allow for both sequential and scalable processing, depend on domain scientists for code parallelization and scalable linear system solvers.

  19. 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.

  20. Bioremediation of nitrates and carbon tetrachloride in groundwater

    SciTech Connect

    Brouns, T.M.

    1993-01-01

    A development and demonstration program is presently underway to test an in situ bioremediation technology for treating nitrates and carbon tetrachloride in contaminated Hanford groundwaters. Several key technical issues have prevented widespread use of bioremediation for cleanup of organic and inorganic subsurface contaminants, including the development of adequate nutrient delivery systems; effective mixing technologies for contacting microorganisms, nutrients, and contaminants; methods to control biofouling or excessive microbial growth; and adequate tools for designing, predicting, and monitoring the performance of in situ technologies in heterogeneous subsurface environments. The goal of this program is to address these technical issues in an integrated laboratory-, bench-, and field-scale demonstration by stimulating native microorganisms and accelerating the natural degradation of NO{sub 3}{sup {minus}} CCl{sub 4} and chloroform.

  1. Bioremediation of nitrates and carbon tetrachloride in groundwater

    SciTech Connect

    Brouns, T.M.

    1993-01-01

    A development and demonstration program is presently underway to test an in situ bioremediation technology for treating nitrates and carbon tetrachloride in contaminated Hanford groundwaters. Several key technical issues have prevented widespread use of bioremediation for cleanup of organic and inorganic subsurface contaminants, including the development of adequate nutrient delivery systems; effective mixing technologies for contacting microorganisms, nutrients, and contaminants; methods to control biofouling or excessive microbial growth; and adequate tools for designing, predicting, and monitoring the performance of in situ technologies in heterogeneous subsurface environments. The goal of this program is to address these technical issues in an integrated laboratory-, bench-, and field-scale demonstration by stimulating native microorganisms and accelerating the natural degradation of NO[sub 3][sup [minus

  2. Reductive dehalogenation of aqueous carbon tetrachloride by sodium dithionite

    SciTech Connect

    Rodriguez, J.C.; Rivera, M.

    1996-12-31

    The search for methods aimed at eliminating halogenated aliphatic hydrocarbons from polluted water has become an area of intensive study in the environmental and health sciences. Considerable interest has been focused on the reductive dehalogenation of chlorinated hydrocarbons produced in large scale for industrial uses. To these ends, methods involving bacterial cultures, enzymes, minerals, transition metals, bimetalic systems, electrodes, sonolysis and photolysis, have been reported in the literature as possible alternatives that display a wide variety of characteristic reaction rates, products and conditions. The generation of toxic reaction byproducts in considerable amounts, however, limits the number of feasible methods to only a few with potential application to real problems. In this communication we report the anaerobic reductive dehalogenation of aqueous carbon tetrachloride (CCl{sub 4}) carried out by sodium dithionite (Na{sub 2}S{sub 2}O{sub 4}).

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. ABIOTIC REDUCTIVE DECHLORINATION OF CARBON TETRACHLORIDE AND HEXACHLOROETHANE BY ENVIRONMENTAL REDUCTANTS

    EPA Science Inventory

    The transformation rates of hexachloroethane (HCA) and carbon tetrachloride (CTET) have been measured in model systems representing the ground water environment and in slurries of fractionated Borden aquifer material. his report summarizes research conducted to identify the envir...

  8. Geostatistical Analyses of the Persistence and Inventory of Carbon Tetrachloride in the 200 West Area of the Hanford Site

    SciTech Connect

    Murray, Christopher J.; Bott, Yi-Ju; Truex, Michael J.

    2007-04-30

    This report documents two separate geostatistical studies performed by researchers from Pacific Northwest National Laboratory to evaluate the carbon tetrachloride plume in the groundwater on the Hanford Site.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. Esculetin Ameliorates Carbon Tetrachloride-Mediated Hepatic Apoptosis in Rats

    PubMed Central

    Tien, Yun-Chen; Liao, Jung-Chun; Chiu, Chuan-Sung; Huang, Tai-Hung; Huang, Chih-Yang; Chang, Wen-Te; Peng, Wen-Huang

    2011-01-01

    Esculetin (ESC) is a coumarin that is present in several plants such as Fraxinus rhynchophylla and Artemisia capillaris. Our previous study found that FR ethanol extract (FREtOH) significantly ameliorated rats’ liver function. This study was intended to investigate the protective mechanism of ESC in hepatic apoptosis in rats induced by carbon tetrachloride. Rat hepatic apoptosis was induced by oral administration of CCl4. All rats were administered orally with CCl4 (20%, 0.5 mL/rat) twice a week for 8 weeks. Rats in the ESC groups were treated daily with ESC, and silymarin group were treated daily with silymarin. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) as well as the activities of the anti-oxidative enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase in the liver were measured. In addition, expression of liver apoptosis proteins and anti-apoptotic proteins were detected. ESC (100, 500 mg/kg) significantly reduced the elevated activities of serum ALT and AST caused by CCl4 and significantly increased the activities of catalase, GPx and SOD. Furthermore, ESC (100, 500 mg/kg) significantly decreased the levels of the proapoptotic proteins (t-Bid, Bak and Bad) and significantly increased the levels of the anti-apoptotic proteins (Bcl-2 and Bcl-xL). ESC inhibited the release of cytochrome c from mitochondria. In addition, the levels of activated caspase-9 and activated caspase-3 were significantly decreased in rats treated with ESC than those in rats treated with CCl4 alone. ESC significantly reduced CCl4-induced hepatic apoptosis in rats. PMID:21747724

  14. Chronic restraint stress reduces carbon tetrachloride-induced liver fibrosis

    PubMed Central

    LI, MENG; SUN, QUAN; LI, SHENGLI; ZHAI, YANAN; WANG, JINGJING; CHEN, BAIAN; LU, JING

    2016-01-01

    Stress as a cofactor has been reported to affect the progression and severity of liver diseases. The present study investigated the effect of chronic restraint stress on carbon tetrachloride (CCl4)-induced liver fibrosis. A total of 30 male BALB/c mice were randomly divided into three groups: Oil-treated control group; CCl4-treated group; and CCl4 + restraint-treated group. CCl4 was administrated via intraperitoneal injection once every 3 days over a period of 42 days. In the CCl4 + restraint-treated group, mice were immobilized using 50 ml centrifuge tubes for 0.5 h to inflict chronic restraint stress immediately after the injection of CCl4. On day 42, blood and liver tissue samples were collected for analysis. The effect of restraint on CCl4-induced liver fibrosis in mice was evaluated by analyzing the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histopathological examination of liver samples was performed using hematoxylin and eosin (HE), Masson's trichrome, 5-hydroxytryptamine 2B (5-HT2B) receptor and α-smooth muscle actin (α-SMA) immumohistochemical staining. ALT, AST, 5-HT2B receptor and α-SMA expression levels were significantly increased in mice exposed to CCl4 in comparison with those in the oil-treated control mice (P<0.01). However, these increases were significantly reduced by exposure to restraint (P<0.05). HE and Masson's trichrome staining revealed that restraint can alleviate CCl4-induced liver fibrosis. These results suggest that chronic restraint stress reduces the development of liver fibrosis by inhibiting the activation of hepatic stellate cells via 5-HT2B receptor. Therefore, restraint may be a useful therapeutic approach in the management of liver fibrosis. PMID:27284296

  15. 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

  16. Self-Templated Synthesis of Mesoporous Carbon from Carbon Tetrachloride Precursor for Supercapacitor Electrodes.

    PubMed

    Tang, Duihai; Hu, Shi; Dai, Fang; Yi, Ran; Gordin, Mikhail L; Chen, Shuru; Song, Jiangxuan; Wang, Donghai

    2016-03-23

    A high-surface-area mesoporous carbon material has been synthesized using a self-templating approach via reduction of carbon tetrachloride by sodium potassium alloy. The advantage is the reduction-generated salt templates can be easily removed with just water. The produced mesoporous carbon has a high surface area and a narrow pore size distribution. When used as a supercapacitor electrode, this material exhibits a high specific capacitance (259 F g(-1)) and excellent cycling performance (>92% capacitance retention for 6000 cycles). PMID:26913815

  17. Fibrogenic and collagenolytic activity in carbon-tetrachloride-injured rats: beneficial effects of zinc administration.

    PubMed

    Giménez, A; Parés, A; Alié, S; Camps, J; Deulofeu, R; Caballería, J; Rodés, J

    1994-09-01

    Collagen synthesis and degradation in normal and carbon-tetrachloride-injured male Wistar rats at early and late stages of liver fibrosis, and the potential beneficial effects of zinc supplementation on liver fibrogenesis and collagenolysis have been assessed by measuring hepatic collagen content and prolyl hydroxylase and collagenase activities. No significant changes in hepatic collagen and prolyl hydroxylase activities were observed between control rats (82 +/- 25 cpm/mg protein) and rats with induced cirrhosis (107 +/- 23 cpm/mg protein) after 4 weeks of carbon tetrachloride injury. By this time, hepatic collagenase activity was significantly lower in rats with induced cirrhosis (61 +/- 9 micro units/mg protein) than in control rats (133 +/- 31 micro units/mg protein) (p < 0.05). This result was prevented by zinc administration, since hepatic collagenase activity was similar in zinc-supplemented, carbon-tetrachloride-injured rats and normal rats (148 +/- 19 micromicrons/mg protein). After 16 weeks, all carbon-tetrachloride-injured rats had cirrhosis. Hepatic collagen content and prolyl hydroxylase activity were significantly higher in carbon-tetrachloride-injured rats than in controls. These effects were partially prevented by zinc administration, since only two of the seven zinc-supplemented, carbon-tetrachloride-injured rats had cirrhosis. Moreover, prolyl hydroxylase activity was significantly lower in zinc-supplemented injured rats (263 +/- 27 cpm/mg protein) than in the non-supplemented respective controls (389 +/- 52 cpm/mg protein) (p < 0.05). No significant changes in hepatic collagenase activity were observed at this stage of liver injury.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7836696

  18. 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.

  19. 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

  20. Surface Reactivity of Core Shell Iron-Iron Oxide Nanoclusters towards Breakdown of Carbon Tetrachloride

    NASA Astrophysics Data System (ADS)

    Tarsem S., Maninder K.; Qiang, You; Kim, Hongseok; Amonette, James E.; Baer, Donald R.

    2012-02-01

    Zero-valent iron (ZVI) is one of the technologies for groundwater remediation to reduce contaminants by removal of mobile chlorinated hydrocarbons. Iron-Iron oxide (Fe/Fe3O4) nanoclusters (NCs) made in our laboratory using cluster deposition technique have enhanced reactivity towards targeted contaminants due to the presence of ZVI protected by a passivated oxide shell. Here, we investigate the effectiveness of the Fe/Fe3O4 NCs in reducing carbon tetrachloride (CT) under laboratory conditions. The reactivity of the NCs was investigated by conducting unbuffered aqueous batch experiments to reduce CT at room temperature. Initial results show that 80% of the degradation of CT resulted in the formation of dichloromethane (DCM) and chloroform (CF); the remainder likely followed a competing pathway to yield nonhazardous products such as CO. The production of undesirable hydrogenated products such as DCM and CF suggests that the dominant reaction pathway occurs through hydrogen (H) atom transfer via H atoms generated by corrosion of the iron. Comparative experiments with ZVI NCs prepared by other methods are underway and the results will be reported. Future work is to analyze and understand factors that control the reaction pathways between desirable and undesirable products.

  1. Carbon tetrachloride in vegetation and its application to expedited site characterization.

    SciTech Connect

    Burton, J. C.; Nashold, B. W.; Walker, J. L.

    1999-06-01

    The use of vegetation analyses to outline areas of near-surface enrichment with metals and organic compounds was pioneered by the mining and petroleum industries. Research and development (R&D) on environmental applications is focusing on the ability of vegetation to remediate soils. Certain contaminants are taken up by plants and either stored in the plant tissue for easy harvesting and removal or changed into products that are not a health concern. In the development of its Expedited Site Characterization (ESC) methodology, our group at Argonne has focused its R&D on the application of vegetation analyses to detect subsurface contamination in vadose zone soils. We have developed the technology to locate past spills or leaks of carbon tetrachloride that penetrated the vadose zone and contaminated underlying drinking water supplies. Vegetation analysis is attractive as a first-step exploratory technique because it is noninvasive, rapid, and inexpensive. The technique requires collection of a uniform, constant sample and an analytical method with a low detection limit and high-quality results.

  2. 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.

  3. 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. PMID:25544995

  4. ORAL TOXICITY OF CARBON TETRACHLORIDE: ACUTE, SUBACUTE, AND SUBCHRONIC STUDIES IN RATS

    EPA Science Inventory

    The investigation was conducted to characterize the acute, subacute and subchronic toxic potency of ingested carbon tetrachloride (CCl4). In the first acute and subchronic toxicity study, male Sprague-Dawley rats of 300-350 g were gavaged with 0, 20, 40 or 80 mg CCl4/kg once dail...

  5. 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...

  6. REDUCTIVE DEHALOGENATION OF HEXACHLOROETHANE, CARBON TETRACHLORIDE, AND BROMOFORM BY ANAHYDROQUINONE DISULFONATE AND HUMIC ACID

    EPA Science Inventory

    The reductive dehalogenation of hexachloroethane (C2CI6), carbon tetrachloride (CC14), and bromoform (CHBr3) was examined at 50 degrees C in aqueous solutions containing either (1) 500 uM of 2,6-anthrahydroquinone disulfonate (AHQDS), (2) 250 uM Fe2+, or (3) 250 uM HS. The pH ran...

  7. 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 ...

  8. IMMUNOTOXICOLOGIC ASSESSMENT OF SUBACUTE EXPOSURE OF RATS TO CARBON TETRACHLORIDE WITH COMPARISON TO HEPATOXICITY AND NEPHROTOXICITY

    EPA Science Inventory

    The immunotoxicity, hepatoxicity and nephrotoxicity of subacute exposure to carbon tetrachloride (CCl4) was evaluated In young adult (8-9 week old) male Fischer 344 rats, dosed by gavage with CCl4 for ten consecutive days at 0, 5, 10, 20 or 40 mg/kg/day. wo days following the las...

  9. 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...

  10. EFFECT OF ROUTE AND PATTERN OF EXPOSURE ON THE PHARMACOKINETICS AND ACUTE HEPATOTOXICITY OF CARBON TETRACHLORIDE

    EPA Science Inventory

    The objectives of this study were to evaluate the influence of both route and pattern of exposure on the pharmacokinetics and target organ toxicity of a common VOC, carbon tetrachloride (CCl4). ale Sprague-Dawley rats, 325-275 g, inhaled 100 or 1,000 ppm CCl4 for 2 hr through a o...

  11. 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.

  12. 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.

  13. 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

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

    PubMed

    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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. Carbon tetrachloride/carbon disulfide exposures in grain fumigation. Final report

    SciTech Connect

    Marano, D.E.; White, K.L.; Deer, H.; Alexander, G.

    1986-03-01

    The use of 80/20 compounds as liquid-fumigant mixtures in the grain-handling industry was considered. Worker exposures to carbon tetrachloride and carbon disulfide were measured at representative facilities throughout the industry. Work practices that may contribute to high exposure levels were cited. Approximately equal amounts of liquid fumigants and solid formulations of phosphine are used throughout the industry. As spraying is done on a sporadic basis, it does not appear likely to present a major problem such as might be encountered in continuous exposure situations. The authors conclude that grain workers do not appear to be an ideal study group for a neurotoxicity morbidity study due to the fact that the physical distance between study sites and the small number of workers at each site makes it difficult logistically. A concerted effort throughout the grain industry to educate those workers in the grain-handling portions of that industry toward the safe handling of fumigants should go far in alleviating any problems arising from exposure to fumigants.

  1. 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

  2. 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.

  3. Abiotic transformation of carbon tetrachloride at mineral surfaces. Final report, September 1990-September 1993

    SciTech Connect

    Kriegman-King, M.; Reinhard, M.

    1994-02-01

    The report addresses the ability of natural mineral surfaces to abiotically transform halogenated organic compounds in subsurface environments. The research focuses on carbon tetrachloride (CC14) as the halogenated organic and biotite, vermiculite, and pyrite as the mineral surfaces. The CCl4 transformation rates and products were quantified under different environmental conditions. The disappearance of CCl4 was significantly faster in the presence of mineral surfaces than in homogeneous solution. In systems containing the sheet silicates and HS-, the rate of reaction was dependent on the temperature, hydrogen sulfide ion concentration, surface concentration, and Fe(II) content in the minerals.

  4. Spectral luminescence and photochemical properties of chlorophyll a in solution containing carbon tetrachloride

    SciTech Connect

    Gruzinskii, V.V.; Gurinovich, V.V.; Sagun, E.I.; Tsvirko, M.P.

    1987-08-01

    Studies were conducted on photophysical and photochemical processes in chlorophyll a in carbon tetrachloride and ether by means of flash photolysis, electron spin resonance, and fluorescence spectroscopy. Lifetimes and quenching of triplet states were analyzed and absorption spectra and fluorescence decay times are given. The kinetics of triplet-triplet absorption and hyperfine structure were determined. An absolute quantum yield of the photochemical reaction was measured within the range of linear dependence of the optical density on the time of chlorophyll a irradiation by a krypton laser and the excitation wavelength of 647.1 nm.

  5. 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.

  6. Action of streptokinase on parameters of hemostasis in rabbits with toxic liver damage due to carbon tetrachloride

    SciTech Connect

    Nikandrov, V.N.; Naumovich, S.A.; Votyakov, V.I.

    1987-07-01

    The authors study the specific nature of changes in the parameters of hemostasis in rabbits with experimental toxic liver damage. Streptokinase was injected intravenously. Toxic liver damage was induced by injections of carbon tetrachloride. The parameters studied included acceleration of lysis of the blood clot, increased fibrinolytic activity and thrombin time, lowered level of fibrinogen and antithrombin III.

  7. 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...

  8. 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...

  9. 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

  10. 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

  11. 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.

  12. Altered circadian rhythm of the clock genes in fibrotic livers induced by carbon tetrachloride.

    PubMed

    Chen, Peng; Kakan, Xiamusiya; Zhang, Jianfa

    2010-04-16

    Disruption in circadian rhythms either by mutation in mice or by shiftwork in people, is associated with an increased risk for the development of multiple organ diseases. In turn, organ disease may influence the function of clock genes and peripheral circadian systems. Here we showed that hepatic fibrosis induced by carbon tetrachloride in mice leads to alterations in the circadian rhythms of hepatic clock genes. Especially, we found an impaired daily Cry2 rhythm in the fibrotic livers, with markedly decreased levels during the day time while compared with control livers. Associatively, the expressions of two important clock-regulated genes peroxisome proliferator-activated receptor alpha and cytochrome P450 oxidoreductase lost circadian rhythm with significantly decreased levels during the light-dark (12/12h) cycle in fibrotic livers. PMID:20233594

  13. Protective effect of diphenylmethyl selenocyanate against carbon tetrachloride-induced hepatotoxicity in vivo.

    PubMed

    Das, Rajat Kumar; Das, Sukta; Bhattacharya, Sudin

    2004-01-01

    Carbon tetrachloride (CCl(4)) is a known hepatotoxic compound working through the generation of reactive free radicals. Selenium (Se) is an essential trace element required by animals and humans for protection against xenobiotic compounds. In this study, Se, as diphenylmethyl selenocyanate, has been evaluated for its protective action against CCl(4)-induced hepatotoxicity in Swiss albino mice. Treatment with Se compound was found to upregulate different phase II detoxifying enzymes (catalase, superoxide dismutases, reduced glutathione, and glutathione transferase) in liver of mice challenged with different doses of CCl(4) as compared to the CCl(4) control, when measured after 24 hours of CCl(4) treatment (p < 0.01). The Se compound also significantly (p < 0.01) inhibited the level of membrane lipid peroxidation and serum transferase activity (ALT and AST) in the treated group as compared to the control group. PMID:15511216

  14. 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.

  15. 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.

  16. 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).

  17. 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

  18. 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. PMID:25323506

  19. 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.

  20. Histochemical studies on the liver of Heteropneustes fossilis treated with carbon tetrachloride.

    PubMed

    Sastry, K V; Agrawal, V P

    1976-01-01

    The effect of carbon tetrachloride on the liver of Heteropneustes fossilis has been studied. It results in centrolobular necrosis and cirrhosis. The hepatocyte nuclei are enlarged and balloon-shaped cells are visible at a few places. There is an increase at this stage in the DNA content of the hepatocyte nucleus. The cytoplasm is heavily laden with glycogen. Fatty infiltration starts and the fat content in the cytoplasm of the liver cells is increased. After 5 h of injection, the nuclei undergo lysis followed by ruptures in the cell membrane. The DNA content is greatly reduced. There is a marked depletion in the glycogen content. The bile canaliculi are filled with the extruded cell contents. The fatty infiltration increases at this stage. PMID:961339

  1. Antihepatotoxic effect of golden berry (Physalis peruviana Linn.) in carbon tetrachloride (CCl4) intoxicated rats.

    PubMed

    Taj, Darakhshan; Khan, Hira; Sultana, Viqar; Ara, Jehan; Ehteshamul-Haque, Syed

    2014-05-01

    Liver is the main site in the body for intense metabolism and excretion. A number of chemicals and drugs which are used routinely cause liver damage. The present study investigates the antihepatotoxic effect of Physalis peruviana whole ripe fruit, water and ethanol extracts of fruit in normal as well as in carbon tetrachloride (CCl(4)) intoxicated rats. The CCl(4) treated rats showed marked elevation in liver enzymes: alanine transaminse, aspratate transaminase, alkaline phosphatase, lactate dehydrogenase and other biochemical parameters: bilirubin, creatinine and urea, thus indicating liver injury. Whereas animal treated/fed with various preparations of Physalis peruviana showed significant lowering effect (p<0.05) in the elevated levels of serum markers like ALAT, ASAT, ALP, LDH, creatinine, urea and bilirubin indicating the protection against hepatic cell damage. The water extract of Physalis peruviana showed highest activity in both rat models while ripe fruit and ethanol extract showed moderate activity compared to standard drug. PMID:24811807

  2. Diverse mechanisms of hepatocellular injuries due to chemicals: evidence in rats administered carbon tetrachloride or dimethylnitrosamine.

    PubMed Central

    Nayak, N. C.; Chopra, P.; Dhar, A.; Das, P. K.

    1975-01-01

    Differences in acute hepatotoxicity of carbon tetrachloride (CCl4) and dimethylnitrosamine (DMN) have been tested in normal foetal, newborn and adult rats, foetal, newborn and adult rats pretreated with phenobarbitone and partially hepatectomized adult rats. While CCl4 is non-toxic to the foetal and newborn liver, DMN induces identical necrosis at all ages. Prior dosing with phenobarbitone augments CCl4 toxicity only in the adult and the newborn but the foetus continues to be resistant. Such pretreatment, on the other hand, significantly reduces the effects of DMN on liver in all animals. Partial hepatectomy makes the liver less susceptible to CCl4 and more so to DMN. Such diversities of hepatic response to the two toxins can be accounted for by the levels of the respective toxifying enzymes in the liver cell in different situations. Images Fig. 1 Fig. 2 Fig. 3 PMID:173382

  3. [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

  4. 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

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

    PubMed

    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 1μM which peaked at 30min. The bioavailability of andrographolide was 1.19%. In a hepatoprotection study, rats were intragastrically dosed with 30 or 50mg/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 (CCl4) at day 6. Andrographolide pretreatment suppressed CCl4-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. PMID:25110055

  6. 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

  7. ASSESSMENT OF THE MUTAGENIC POTENTIAL OF CARBON DISULFIDE, CARBON TETRACHLORIDE, DICHLOROMETHANE, ETHYLENE DICHLORIDE, AND METHYL BROMIDE: A COMPARATIVE ANALYSIS IN RELATION TO ETHYLENE DIBROMIDE

    EPA Science Inventory

    The document provides an evaluation of the mutagenic potential of five alternative fumigants to ethylene dibromide(EDB). These include carbon disulfide(CS2), carbon tetrachloride(CCl4), dichloromethane(DCM), ethylene dichloride(EDC), and methyl bromide (MB). Of the five proposed ...

  8. Waste Management Plan for the Expedited Response Action for 200 West Area Carbon Tetrachloride Plume & the 200-ZP-1 & 200-PW-1 Operable Units

    SciTech Connect

    BYRNES, M.E.

    2003-05-01

    The 200 West Area carbon tetrachloride plume expedited response action (ERA) involves both passive and active vapor extraction, and this document includes the requirements for management and disposal of waste generated with the 200-ZP-1 Operable Unit.

  9. 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...

  10. 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. PMID:25127387

  11. 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...

  12. 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

  13. 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

  14. Enhanced reductive degradation of carbon tetrachloride by biogenic vivianite and Fe(II)

    NASA Astrophysics Data System (ADS)

    Bae, Sungjun; Lee, Woojin

    2012-05-01

    We demonstrated that reductive dechlorination of carbon tetrachloride (CT) can be enhanced by iron-bearing soil minerals (IBSMs) in the presence of Shewanella putrefaciens CN32 (CN32) due to the formation of biogenic vivianite and Fe(II). The bioreduction efficiency of magnetite was the highest (51.1%), followed by lepidocrocite (25.7%), goethite (3.6%), and hematite (1.8%). The dechlorination kinetic of CT by lepidocrocite (0.043 d-1) in the presence of CN32 was three times faster than that by microbial transformation with CN32 (0.014 d-1). Chloroform (16.1-29.4%), carbon monoxide (2.4-23.8%), and formate (0-58.0%) were measured as main products for the degradation of CT by magnetite and lepidocrocite in the presence of CN32. X-ray diffraction and electron microscope analyses revealed that the biogenic vivianite can form during the CT degradation in magnetite and lepidocrocite suspensions with CN32. The dechlorination kinetics of CT by chemogenic vivianite was much faster than that by magnetite and lepidocrocite with CN32. The highest formate production (84.2%) was observed during a full degradation of CT by the chemogenic vivianite. The experimental results showed that biogenic vivianite and sorbed Fe(II) formed during the bioreduction of IBSMs played a pivotal role for the reductive dechlorination of CT.

  15. 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

  16. Relationship between hepatic lipid peroxidation and fibrogenesis in carbon tetrachloride-treated rats: effect of zinc administration.

    PubMed

    Camps, J; Bargallo, T; Gimenez, A; Alie, S; Caballeria, J; Pares, A; Joven, J; Masana, L; Rodes, J

    1992-12-01

    1. Lipid peroxidation and hepatic fibrogenesis were investigated in 25 carbon tetrachloride-treated rats and in 25 control animals. Rats were further divided into two groups to receive either a standard diet or one supplemented with zinc. From each group, animals were killed at weeks 3 and 18 of the experiment for histological and biochemical assessments which included hepatic lipid peroxide and collagen concentrations and plasma zinc concentration as well as the hepatic activities of proline hydroxylase and collagenase. 2. Results indicated that oral zinc supplementation was associated with a decrease in lipid peroxidation (mean 51%; P < 0.05), collagen deposition (mean 32%; P < 0.001) and proline hydroxylase activity (mean 30%; P < 0.05) at week 18, together with an increase in collagenase activity (mean 208%; P < 0.01) at week 3, in carbon tetrachloride-treated rats. 3. There was a significant direct correlation between lipid peroxidation and proline hydroxylase activity in carbon tetrachloride-treated rats (r = 0.52; P < 0.01) and also a significant inverse correlation between lipid peroxidation and plasma zinc concentration in these animals (r = -0.62; P < 0.001). 4. These findings are consistent with the hypothesis that hepatic lipid peroxidation plays an important role in the aetiology of hepatic fibrogenesis and that zinc mitigates the process. PMID:1336440

  17. 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

  18. 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.

  19. 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. PMID:27138348

  20. Carbon tetrachloride-induced kidney damage and protective effect of Amaranthus lividus L. in rats.

    PubMed

    Yilmaz-Ozden, Tugba; Can, Ayse; Karatug, Ayse; Pala-Kara, Zeliha; Okyar, Alper; Bolkent, Sehnaz

    2016-06-01

    This study was designed to evaluate the protective effect of water extract of Amaranthus lividus L. (A. lividus) (Amaranthaceae) on carbon tetrachloride (CCl4)-induced toxicity in kidneys of rats. For this purpose, male albino Wistar rats were pretreated with A. lividus (250 and 500 mg/kg body weight (b.w.)) daily for 9 days and a single dose of CCl4 was applied intraperitoneally (50% in olive oil; 1.5 mL/kg b.w.) on the 10th day. All rats were killed 24 h after CCl4 administration, and kidneys were excised and used for determination of histopathological and biochemical parameters. CCl4 administration caused a remarkable increase in lipid peroxidation (LPO) and glutathione levels and glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, myeloperoxidase (MPO) activities and a decrease in catalase (CAT) activity when compared to the control group. Pretreatment with A. lividus (250 and 500 mg/kg b.w.) significantly prevented the elevation in LPO level and MPO activity as well as protected the decrease in CAT activity but did not alter other biochemical parameters. The protective effect of A. lividus was further evident through the decreased histological alterations in kidneys. In conclusion, this study has indicated that A. lividus possesses protective and antioxidant effects against CCl4-induced oxidative kidney damage. PMID:25415872

  1. Hepatoprotective effect of methylsulfonylmethane against carbon tetrachloride-induced acute liver injury in rats.

    PubMed

    Kamel, Rehab; El Morsy, Engy M

    2013-09-01

    This study evaluated the effect of methylsulfonylmethane (MSM) on carbon tetrachloride (CCl₄)-induced acute liver injury in rats. A single injection of CCl₄ (2 ml/kg, i.p.) increased serum aminotransferases (ALT and AST) activities. In addition, CCl₄ treatment led to elevation of hepatic malondialdehyde (MDA) content as well as decrease in superoxide dismutase (SOD) and catalase (CAT) activities. Furthermore, cytochrome P450 2E1 (CYP2E1) content was suppressed while proinflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels increased in liver tissue after CCl4 administration. We showed that acute CCl₄-induced damage was accompanied by a rise in Bax/Bcl₂ ratio indicating apoptosis. Pre-treatment with MSM (400 mg/kg) inhibited the increases of serum ALT and AST activities, decreased hepatic MDA, TNF-α, IL-6 and Bax/Bcl₂ ratio compared to CCl₄ treated group. On the other hand, MSM raised SOD and CAT activities as well as CYP2E1 level in liver tissues. The present study shows that MSM possesses a hepatoprotective effect against CCl₄-induced liver injury in rats. This protective effect might be through its antioxidant, anti-inflammatory and antiapoptotic properties. PMID:23591777

  2. Dendritic Cell Regulation of Carbon Tetrachloride-induced Murine Liver Fibrosis Regression

    PubMed Central

    Jiao, JingJing; Sastre, David; Isabel Fiel, Maria; Lee, Ursula E.; Ghiassi-Nejad, Zahra; Ginhoux, Florent; Vivier, Eric; Friedman, Scott L.; Merad, Miriam; Aloman, Costica

    2011-01-01

    Although hepatic fibrosis typically follows chronic inflammation, fibrosis will often regress after cessation of liver injury. Here we examined whether liver dendritic cells (DC) play a role in liver fibrosis regression using carbon tetrachloride (CCl4) to induce liver injury. We examined DC dynamics during fibrosis regression and their capacity to modulate liver fibrosis regression upon cessation of injury. We show that conditional DC depletion soon after discontinuation of the liver insult leads to delayed fibrosis regression and reduced clearance of activated hepatic stellate cells, the key fibrogenic cell in liver. Conversely, DC expansion induced either by Flt3L (Fms-like tyrosine kinase-3 ligand) or adoptive transfer of purified DC accelerates liver fibrosis regression. DC modulation of fibrosis was partially dependent on MMP-9, as MMP-9 inhibition abolished Flt3L-mediated effect and the ability of transferred DC to accelerate fibrosis regression. In contrast, transfer of DC from MMP-9 deficient mice failed to improve fibrosis regression. Conclusion Altogether, these results suggest that DC increase fibrosis regression, and that the effect is correlated with their production of MMP-9. These results also suggest that Flt3L treatment during fibrosis resolution merits evaluation to accelerate regression of advanced liver fibrosis. PMID:21898476

  3. 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

  4. Carbon tetrachloride-induced lipid peroxidation and hyperglycemia in rat: a novel study.

    PubMed

    Khan, Rahmat Ali; Khan, Muhammad Rashid; Sahreen, Sumaira; Ahmed, Mushtaq; Shah, Naseer Ali

    2015-06-01

    Launaea procumbens methanol extract (LPME) was evaluated against carbon tetrachloride (CCl4)-induced pancreatic oxidative damage and hyperglycemia in rats. Various doses of the extract were administered to rats after 48 h of CCl4 treatment (3 ml/kg bodyweight (bw); intraperitoneally, 20% CCl4/olive oil) twice a week for 4 weeks. Coadministration of various concentrations of LPME (100, 150 and 200 mg/kg) ameliorated the toxicity of CCl4 and reversed the serum level of enzymes (amylase and lipase), glucose and hormone (insulin). The extract was able to reduce thiobarbituric acid reactive substance but increased the glutathione contents in pancreatic tissue. Depletion of antioxidant enzyme activities (catalase, peroxidase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase and glutathione-S-reductase) and DNA damages induced with CCl4 were restored by LPME supplement. It is suggested that LPME effectively protects the liver against the CCl4-induced oxidative damage in rats, possibly through antioxidant and/or free radical scavenging effects of flavonoids and phenolic compounds in the extract. PMID:23416881

  5. Carbon tetrachloride degradation: Effect of microbial growth substrate and vitamin B{sub 12} content

    SciTech Connect

    Zou, S.; Stensel, H.D.; Ferguson, J.F.

    2000-05-01

    Microbial degradation kinetics of carbon tetrachloride (CT) under reducing conditions were investigated for different cultures, fed with 1,2-propanediol, dextrose, propionalde-hyde, or acetate and nitrate, in the anaerobic step of an anaerobic/aerobic operation sequence. Methanogenesis was inhibited due to the aerobic step. CT biodegradation rates followed first-order kinetics with respect to CT concentration and biomass and were not affected by the presence of growth substrate. CT degradation rates increased linearly with higher intracellular vitamin B{sub 12} content. The culture fed 1,2-propanediol had the highest vitamin B{sub 12} content, which was 3.8, 4.7, and 16 times that of the propionaldehyde-,dextrose-, and acetate-fed cultures, respectively, and its first-order degradation rate constant was 2.8, 4.5, 6.0 times that for those cultures, respectively. No CT degradation occurred with culture liquid, suggesting that intracellular factors were responsible for CT degradation. The propanediol culture was able to sustain a constant CT degradation rate for a 16-day test period without substrate addition. Compared to a propanediol-fed culture grown only under anaerobic conditions, the propanediol culture grown under the sequential anaerobic/aerobic condition resulted in more biomass growth and a greater CT degradation rate per unit of propanediol fed, although its CT degradation rate per unit of biomass was lower.

  6. A theoretical study of the sum frequency vibrational spectroscopy of the carbon tetrachloride/water interface

    NASA Astrophysics Data System (ADS)

    Green, Anthony J.; Perry, Angela; Moore, Preston B.; Space, Brian

    2012-03-01

    Theoretical approximations to the sum frequency vibrational spectroscopy (SFVS) of the carbon tetrachloride/water interface are constructed using the quantum-corrected time correlation functions (TCF) to aid in interpretation of experimental data and to predict novel vibrational modes. Instantaneous normal mode (INM) methods are used to characterize the observed modes leading to the TCF signal, thus providing molecular resolution of the vibrational lineshapes. Detailed comparisons of the theoretical signals are made with those obtained experimentally and show excellent agreement for the spectral peaks in the O-H stretching region of water. An intermolecular mode, unique to the interface, at 848 cm-1 is also identifiable, similar to the one seen for the water/vapor interface. INM analysis reveals the resonance is due to a wagging mode (hindered rotation) that was previously identified (Perry et al 2005 J. Chem. Phys. 123 144705) as localized on a single water molecule with both hydrogens displaced normal to the interface—generally it is found that the symmetry breaking at the interface leads to hindered translations and rotations at hydrophilic/hydrophobic interfaces that assume finite vibrational frequencies due to anchoring at the aqueous interface. Additionally, examination of the real and imaginary parts of the theoretical SFVS spectra reveal the spectroscopic species attributed the resonances and possible subspecies in the O-H region; these results are consistent with extant experimental data and associated analysis.

  7. 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

  8. 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

  9. 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.

  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. Effects of indoleamine 2,3-dioxygenases in carbon tetrachloride-induced hepatitis model of rats.

    PubMed

    Li, Dan; Cai, Haidong; Hou, Min; Fu, Da; Ma, Yushui; Luo, Qiong; Yuan, Xueyu; Lv, Mingli; Zhang, Xiaoping; Cong, Xianling; Lv, Zhongwei

    2012-06-01

    Indoleamine 2,3-dioxygenase (IDO) converts tryptophan to l-kynurenine, and it is noted as a relevant molecule in promoting tolerance and suppressing adaptive immunity. In this study, to investigate the effects of IDO in carbon tetrachloride (CCl(4) )-induced hepatitis model, the levels of IDO enzymic activities in the mock group, the control group and the 1-methyl-D-tryptophan (1-MT)-treated group were confirmed by determination of l-kynurenine concentrations. Serum alanine aminotransferase levels in 1-MT-treated rats after CCl(4) injection significantly increased compared with those in mock and control groups. In CCl(4)-induced hepatitis models, tumour necrosis factor-α (TNF-α) is critical in the development of liver injury. The mRNA expression and secretion levels of TNF-α in the liver from 1-MT-treated rats were more enhanced compared with those in the mock and the control groups. Moreover, the levels of cytokine and chemokine from mock, control group and 1-MT-treated rats after treated with CCl(4) were analyzed by ELISA, and the level of interleukin-6 was found to increase in 1-MT-treated rats. It was concluded that the deficiency of IDO exacerbated liver injury in CCl(4)-induced hepatitis and its effect may be connected with TNF-α and interleukin-6. PMID:22249930

  12. Anti-fibrotic effects of neferine on carbon tetrachloride-induced hepatic fibrosis in mice.

    PubMed

    Chen, Mo-Si; Zhang, Jia-Hua; Wang, Jia-Ling; Gao, Lu; Chen, Xiao-Xu; Xiao, Jun-Hua

    2015-01-01

    The effects of neferine, a bisbenzylisoquinline alkaloid extracted from the seed embryo of the Chinese traditional medicine Nelumbo nucifera Gaertn, on carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice were evaluated. Adult male Kunming mice were administered with CCl4 1 ml/kg via intraperitoneal injection twice a week for 8 weeks. At the beginning of the 9th week, mice were treated with normal saline, colchicine (0.1 mg/kg), and neferine (5, 10, 20 mg/kg) via intraperitoneal injection once a day for 2 weeks. The liver index and histological examination, plasma ALT/AST levels, hydroxyproline and TGF-β1 content of liver tissue were examined. In the model group, the liver index, the hydroxyproline content of liver tissue and plasma ALT/AST levels were increased, and a high expression of TGF-β1 was observed. The abnormal changes could be improved by neferine in a dose-dependent manner. Our data showed that neferine had an antifibrosis effect on CCl4-induced hepatic fibrosis in mice, possibly partly due to the decreased expression of TGF-β1 in the liver. PMID:25800905

  13. 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

  14. 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.

  15. Amelioration of carbon tetrachloride induced hepatotoxicity in rats by standardized Feronia limonia. Linn leaf extracts

    PubMed Central

    Jain, Mahendra; Kapadia, Rakhee; Jadeja, Ravirajsinh N.; Thounaojam, Menaka C.; Devkar, Ranjitsinh V.; Mishra, S.H.

    2012-01-01

    The hepatoprotective potential of standardized Feronia limonia (Family, Rutaceae) methanolic extract (FL-7) and chloroform soluble fraction (FL-9) were assessed against carbon tetrachloride (CCl4) induced oxidative stress and hepatotoxicity in rats. Rats treated with CCl4 recorded significant elevation in plasma markers of hepatic injury, alteration in hepatic antioxidant status and histopathological damages. However, rats pretreated with FL-7 (200 or 400 mg/kg, p.o.) and FL-9 (100 or 200 mg/kg, p.o.) for 7 days and later administered CCl4 (0.5 ml/kg, i.p.) recorded lowered indices of the above mentioned parameters and minimal histological damage in a dose dependent manner. These results were comparable to that of CCl4+silymarin treated rats. The results obtained with FL-7 and FL-9 are attributable to their free radical scavenging potential due to high contents of polyphenols and flavonols recorded herein. Overall, this study establishes the efficacy of FL-7 and FL-9 as hepatoprotective agents against CCl4 induced hepatotoxicity in rats. PMID:27418903

  16. Hepatoprotective activity of Symplocos racemosa bark on carbon tetrachloride-induced hepatic damage in rats

    PubMed Central

    Wakchaure, Dhananjay; Jain, Dilpesh; Singhai, Abhay Kumar; Somani, Rahul

    2011-01-01

    The present study aims to evaluate the hepatoprotective activity of ethanol extract of Symplocos racemosa (EESR) bark on carbon tetrachloride (CCl4)-induced hepatic damage in rats. CCl4 with olive oil (1 : 1) (0.2 ml/kg, i.p.) was administered for ten days to induce hepatotoxicity. EESR (200 and 400 mg/kg, p.o.) and silymarin (100 mg/kg p.o.) were administered concomitantly for fourteen days. The degree of hepatoprotection was measured using serum transaminases (AST and ALT), alkaline phosphatase, bilirubin, albumin, and total protein levels. Metabolic function of the liver was evaluated by thiopentone-induced sleeping time. Antioxidant activity was assessed by measuring liver malondialdehyde, glutathione, catalase, and superoxide dismutase levels. Histopathological changes of liver sample were also observed. Significant hepatotoxicity was induced by CCl4 in experimental animals. EESR treatment showed significant dose-dependent restoration of serum enzymes, bilirubin, albumin, total proteins, and antioxidant levels. Improvements in hepatoprotection and morphological and histopathological changes were also observed in the EESR treated rats. It was therefore concluded that EESR bark is an effective hepatoprotective agent in CCl4-induced hepatic damage, and has potential clinical applications for treatment of liver diseases. PMID:22022156

  17. Effective protection of Terminalia catappa L. leaves from damage induced by carbon tetrachloride in liver mitochondria.

    PubMed

    Tang, Xinhui; Gao, Jing; Wang, Yanping; Fan, Yi-Mei; Xu, Li-Zhi; Zhao, Xiao-Ning; Xu, Qiang; Qian, Zhong Ming

    2006-03-01

    The protective effects of chloroform extracts of Terminalia catappa L. leaves (TCCE) on carbon tetrachloride (CCl4)-induced liver damage and the possible mechanisms involved in the protection were investigated in mice. We found that increases in the activity of serum aspartate aminotransferase and alanine aminotransferase and the level of liver lipid peroxidation (2.0-fold, 5.7-fold and 2.8-fold) induced by CCl4 were significantly inhibited by oral pretreatment with 20, 50 or 100 mg/kg of TCCE. Morphological observation further confirmed the hepatoprotective effects of TCCE. In addition, the disruption of mitochondrial membrane potential (14.8%), intramitochondrial Ca2+ overload (2.1-fold) and suppression of mitochondrial Ca2+-ATPase activity (42.0%) in the liver of CCl4-insulted mice were effectively prevented by pretreatment with TCCE. It can be concluded that TCCE have protective activities against liver mitochondrial damage induced by CCl4, which suggests a new mechanism of the hepatoprotective effects of TCCE. PMID:16169207

  18. 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

  19. 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

  20. 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

  1. Hepatoprotective and Immunosuppressive Effect of Synedrella nodiflora L. on Carbon Tetrachloride (CCl4)-Intoxicated Rats.

    PubMed

    Gnanaraj, Charles; Shah, Muhammad Dawood; Haque, A T M Emdadul; Makki, Jaafar Sadeq; Iqbal, Mohammad

    2016-01-01

    Synedrella nodiflora is a medicinal plant that is used by the natives of Sabah, Malaysia to treat rheumatism and several other ailments. This study aims to evaluate the ability of the crude aqueous extract of S. nodiflora leaves to protect against carbon tetrachloride (CCl4)-mediated hepatic injury in rats. S. nodiflora aqueous extract was orally administered to adult Sprague Dawley rats once daily for 14 days (150 and 300 mg/kg body weight [b.w.]) before CCl4 oral treatment (1.0 mL/kg b.w.) on the 13th and 14th days. Serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), hepatic antioxidant enzymes, and malondialdehyde (MDA) levels were estimated. Immunohistochemistry was performed for oxidative stress markers (4-hydroxynonenal [HNE], 8-hydroxy-deoxyguanosine [8-OHdG]) and proinflammatory markers (tumor necrosis factor-α, interleukin-6, prostaglandin E2). Biochemical, immunohistochemical, histological, and ultrastructural findings were in agreement to support the hepatoprotective effect of S. nodiflora against CCl4-mediated oxidative hepatic damage. Hepatoprotective effects of S. nodiflora might be attributable to the presence of phenolic antioxidants and their free radical scavenging property. PMID:27279582

  2. 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

  3. 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. PMID:26742325

  4. 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.

  5. 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

  6. Aqueous extract of Anoectochilus formosanus attenuate hepatic fibrosis induced by carbon tetrachloride in rats.

    PubMed

    Shih, C C; Wu, Y W; Lin, W C

    2005-06-01

    The aim of this study was to investigate the effects of aqueous extract of Anoectochilus formosanus (AFE) on liver fibrogenesis in carbon tetrachloride (CCl4)-induced cirrhosis. Fibrosis was induced in rats by oral administration of CCl4 (20%, 0.5 ml/rat, p.o.) twice a week for 8 weeks. AFE (0.5 and 2.0 g/kg, p.o., daily for 8 weeks) was administered to rats simultaneously. AFE showed reducing actions on the elevated levels of GOT and GPT caused by CCl4. Liver fibrosis in rats induced by CCl4 led to the drop of serum albumin concentration; the AFE increased the albumin concentration. The CCl4-induced liver fibrosis markedly caused liver atrophy and splenomegalia, while AFE increased the liver weight, and decreased the spleen weight. The CCl4-induced liver fibrosis decreased the protein content, and increased collagen contents in rat's liver. AFE significantly increased the contents of protein and reduced the amount of collagen in the liver. In CCl4-treated rats, glutathione concentrations of liver were not affected. AFE significantly increased liver glutathione concentrations. All these results clearly demonstrate that AFE can reduce the liver fibrogensis in rats induced by CCl4. PMID:16008122

  7. 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

  8. Alleviation of Carbon-Tetrachloride-Induced Liver Injury and Fibrosis by Betaine Supplementation in Chickens

    PubMed Central

    Tsai, Meng-Tsz; Chen, Ching-Yi; Pan, Yu-Hui; Wang, Siou-Huei; Mersmann, Harry J.; Ding, Shih-Torng

    2015-01-01

    Betaine is a food component with well-reported hepatoprotection effects. However, the effects and mechanisms of betaine on liver fibrosis development are still insufficient. Because metabolic functions of chicken and human liver is similar, we established a chicken model with carbon Tetrachloride- (CCl4-) induced fibrosis for studying antifibrotic effect of betaine in vivo and in vitro. Two-week-old male chicks were supplemented with betaine (1%, w/v) in drinking water for 2 weeks prior to the initiation of CCl4 treatment (i.p.) until sacrifice. Primary chicken hepatocytes were treated with CCl4 and betaine to mimic the in vivo supplementation. The supplementation of betaine significantly alleviated liver fibrosis development along with the inhibition of lipid peroxidation, hepatic inflammation cytokine, and transforming growth factor-β1 expression levels. These inhibitive effects were also accompanied with the attenuation of hepatic stellate cell activation. Furthermore, our in vitro studies confirmed that betaine provides antioxidant capacity for attenuating the hepatocyte necrosis by CCl4. Altogether, our results highlight the antioxidant ability of betaine, which alleviates CCl4-induced fibrogenesis process along with the suppression of hepatic stellate cells activation. Since betaine is a natural compound without toxicity, we suggest betaine can be used as a potent nutritional or therapeutic factor for reducing liver fibrosis. PMID:26491462

  9. Protective effects of Ocimum gratissimum polyphenol extract on carbon tetrachloride-induced liver fibrosis in rats.

    PubMed

    Chen, Yieng-How; Chiu, Yung-Wei; Shyu, Jyh-Cherng; Tsai, Chin-Chiu; Lee, Hsueh-Hui; Hung, Chuan-Chen; Hwang, Jin-Ming; Liu, Jer-Yuh; Wang, Wen-Hong

    2015-02-28

    Ocimum gratissimum found in tropical regions is a traditional herb commonly which prevents free radical damage and protects liver from oxidative stress and fibrosis. Ocimum gratissimum polyphenol extract (OGPE) was purified by resin tube to 33.24% polyphenol and 8.2% flavonoid, which were three-fold higher compared with the pre-purification concentrations. The abstract was used to determine if the antioxidant components in the O. gratissimum extract (OGE) were responsible for protective effects on liver fibrosis. High-performance liquid chromatography analysis revealed that the content levels of catechin, caffeic acid and epicatechin in OGPE also increased three-fold. Male Wistar rats were administered with carbon tetrachloride (CCl₄) and varying amounts of OGPE doses [0-12 mg/kg body weight (BW)] or OGE dose (40 mg/kg BW) for 8 weeks. Results showed that OGPE at 12 mg/kg BW, similar to OGE at 40 mg/kg BW, maintained the liver weight, significantly ameliorated CCl₄-induced steatosis, and mitigated other pathological changes. OGPE (12 mg/kg BW) also maintained the levels of serum alanine aminotransferase and aspartate aminotransferase, as well as the levels of malondialdehyde, catalase and α-smooth muscle actin in liver tissues from CCl₄-induced changes. These findings suggest that antioxidant components in OGPE were the major factors that prevented liver fibrosis. Moreover, higher polyphenol concentrations were necessary for higher effectiveness. PMID:25687492

  10. Simulation of microbial transport and carbon tetrachloride biodegradation in intermittently-fed aquifer columns

    NASA Astrophysics Data System (ADS)

    Phanikumar, M. S.; Hyndman, David W.; Wiggert, David C.; Dybas, Michael J.; Witt, Michael E.; Criddle, Craig S.

    2002-04-01

    This paper evaluates the microbial transport and degradation processes associated with carbon tetrachloride (CT) biodegradation in laboratory aquifer columns operated with a pulsed microbial feeding strategy. A seven component reactive transport model based on modified saturation kinetics and on a two-site sorption model was developed to describe the linked physical, chemical, and biological processes involved in CT degradation by Pseudomonas stutzeri KC, a denitrifying bacterium that cometabolically converts CT to harmless end products. After evaluating several expressions for attachment and detachment, we selected a dynamic partitioning model in which strain KC detachment decreases at low substrate concentrations. The resulting model enabled improved understanding of the complex coupled processes operative within our system and enabled us to test a model for field-scale design and transport studies. Batch studies were used to identify initial degradation and microbial transport processes, and constrained optimization methods were used to estimate a set of reaction rates that best describe the column experiment data. The optimal set of parameters for one column provided a reasonable prediction of solute and microbial concentrations in a second column operated under different conditions, providing an initial test of the model. This modeling strategy improved our understanding of biodegradation processes and rates. The CT degradation rate in the columns was lower than values obtained from batch studies, and processes in addition to the growth and decay of strain KC cells (due to native flora) are necessary to describe the observed nitrate consumption.

  11. Ameliorative effects of pomegranate on carbon tetrachloride hepatotoxicity in rats: A molecular and histopathological study.

    PubMed

    Ibrahim, Zein Shaban; Nassan, Mohamed Abdo; Soliman, Mohamed Mohamed

    2016-04-01

    The present study aimed to investigate the molecular mechanism underlying the hepatoprotective effects of pomegranate (POM) against oxidative stress in a rat model of carbon tetrachloride (CCl4)-induced liver damage. Injection of rats with CCl4 resulted in hepatic inflammation and lipid accumulation via the upregulation of interleukin (IL)‑6 and sterol regulatory element‑binding protein 1c (SREBP‑1c) mRNA expression. CCl4 induced downregulation of the anti‑inflammatory factors alpha 2‑macroglobulin (α‑2M) and IL‑10 in comparison with the POM treated group. In addition, CCl4 induced downregulation of superoxide dismutase (SOD), glutathione S‑transferase (GST) and catalase (CAT) expression. Conversely, prior administration of POM counteracted the deleterious alterations induced by CCl4. POM downregulated CCl4-induced IL‑6 upregulation, normalized the increase in SREBP‑1c expression, and prevented CCl4‑induced α‑2M downregulation. POM counteracted CCL4‑induced alterations via immunosuppressive, anti‑inflammatory and regenerative effects by upregulating transforming growth factor‑β1, HSP70 and IL-10 mRNA expression. In addition, POM increased reactive oxygen species scavenging activity by augmenting the antioxidant defense mechanism against CCl4 hepatotoxicity, as demonstrated by detecting SOD, CAT and GST expression. These results confirm that, at the molecular level, POM exerts hepatoprotective effects against CCl4‑induced oxidative stress and liver tissue damage. PMID:26936425

  12. Protective effect of potato peel extract against carbon tetrachloride-induced liver injury in rats.

    PubMed

    Singh, Nandita; Kamath, Vasudeva; Narasimhamurthy, K; Rajini, P S

    2008-09-01

    Our earlier studies have shown that extracts derived from potato peel (PPE) are rich in polyphenols and possess strong antioxidant activity both in vitro and in vivo. The objective of the present study was to investigate its potential to offer protection against acute liver injury in rats. Rats pretreated with PPE (oral, 100mg/kgb.w./day for 7 days) were administered a single oral dose carbon tetrachloride (CCl(4), 3ml/kg b.w., 1:1 in groundnut oil) and sacrificed 8h of post-treatment. Hepatic damage was assessed by employing biochemical parameters (transaminase enzyme levels in plasma and liver [AST-aspartate transaminase; ALT-alanine transaminase, LDH-lactate dehydrogenase]). Further, markers of hepatic oxidative damage were measured in terms of malondialdehyde (MDA), enzymic antioxidants (CAT, SOT, GST, GPX) and GSH (reduced glutathione) levels. In addition, the CCl(4)-induced pathological changes in liver were evaluated by histopathological studies. Our results demonstrated that pretreatment of rats with PPE significantly prevented the increased activities of AST and ALT in serum, prevented the elevation of hepatic MDA formation as well as protected the liver from GSH depletion. PPE pretreatment also restored CCl(4)-induced altered antioxidant enzyme activities to control levels. The protective effect of PPE was further evident through the decreased histological alterations in liver. Our findings provide evidences to demonstrate that PPE pretreatment significantly offsets CCl(4)-induced liver injury in rats, which may be attributable to its strong antioxidant propensity. PMID:21791371

  13. 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

  14. Hepatoprotective Effect of Ficus carica Leaf Extract on Mice Intoxicated with Carbon Tetrachloride

    PubMed Central

    Aghel, Nasrin; Kalantari, Heibatollah; Rezazadeh, Shohreh

    2011-01-01

    Protective action of Ficus carica leaf ethanolic extract (obtained by maceration) was evaluated in an animal model of hepatotoxicity induced by carbon tetrachloride (CCl4). Male albino mice were divided into six groups. group I was normal control group; group II received olive oil (CCl4 solvent), groups III-VI received CCl4. After inducing hepatic damage, group III served as control for CCl4; and groups IV- VI received different doses of Ficus carica ethanol extract (200, 400 and 800 mg/kg) prior to intoxication with CCl4. Liver marker enzymes were assayed in serum. Sections of livers were observed under microscope for the histopathological changes. Levels of marker enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased significantly in CCl4 treated mice (group III). In groups IV, V and VI, pre-treated with the plant extract and intoxicated with CCl4, decreased activities of these two enzymes were observed. Also, pre-treatment with the extract in these groups resulted in less pronounced destruction of the liver architecture with no fibrosis and moderate inflammation was observed compared with group III. The present observations suggested that the treatment with Ficus carica leaf extract in dose of 200 mg/kg enhanced protection against CCl4 induced hepatic damage. PMID:24363682

  15. Ex vivo assessment of carbon tetrachloride (CCl(4))-induced chronic injury using polarized light spectroscopy.

    PubMed

    Ahmad, Manzoor; Ali, Safdar; Mehmood, Malik Sajjad; Ali, Hamid; Khurshid, Ahmat; Firdous, Shamaraz; Muhammad, Saleh; Ikram, Masroor

    2013-12-01

    The liver performs various functions, such as the production and detoxification of chemicals; therefore, it is susceptible to hepatotoxins such as carbon tetrachloride (CCl4), which causes chronic injury. Thus, assessment of injury and its status of severity are of prime importance. Current work reports an ex vivo study for probing the severance of hepatic injury induced by CCl4 with polarized light over the spectral range 400-800 nm. Different concentrations of CCl4 were used to induce varying severity of hepatic injury in a rat model. Linear retardance, depolarization rates, and diagonal Mueller matrix elements (m22, m33, and m44), were successfully used as the distinguishing criterion for normal and different liver injuries. Our results show that linear retardance for injured liver samples with lower doses of CCl4 tends to increase when compared with normal liver samples, while samples injured at higher doses of CCl4 offer almost no retardance. Total, linear, and circular depolarizations follow decreasing trends with increased liver injury severity over the entire investigated wavelength range. Linear polarization states were observed to be better maintained as compared to circular polarization states for all samples. Furthermore, numerical values of diagonal elements of the experimentally measured Mueller matrix also increase with increasing doses of CCl4. Liver fibroses, change in transport albedo, and the relative refractive index of the extracellular matrix caused by CCl4 are responsible for the observed differences. These results will provide a pathway to gauge the severity of injury caused by toxic chemicals. PMID:24359651

  16. Histoprotective effect of vitamin D against carbon tetrachloride nephrotoxicity in rats.

    PubMed

    Elmubarak, Smeo; Özsoy, N

    2016-07-01

    This study investigated the protective effect of vitamin D against carbon tetrachloride (CCl4)-induced nephrotoxicity in rats. Adult male Wistar albino rats were divided into four groups ((A) control; (B) 10-week exposure to CCl4; (C) 10-week exposure to CCl4 + vitamin D treatment; and (D) 10-week exposure to CCl4 + 12 weeks of vitamin D treatment). The CCl4 dose (1.5 ml kg(-1)) was injected subcutaneously twice a week, while the 0.5 mg kg(-1) dose of vitamin D was administered intraperitoneally every day, as appropriate for each group. Whole animal and kidney weights as well as serum urea, creatinine, and glucose levels were measured. Kidney tissue sections were stained with hematoxylin-eosin, Masson's trichrome, and periodic acid-Schiff. Tubular and glomerular degeneration were detected in the kidney tissues of CCl4-treated rats, together with dilatation and vacuolization within the tubules and hemorrhage in the intertubular region. In the kidney glomeruli; congestion, atrophy, and adhesion to parietal layer were observed. Tissue disorganization and aggregation of Bowman's capsules were noted. Mononuclear cell infiltration was observed between the glomeruli and the tubules. In contrast, the kidney sections and functional parameters of vitamin D-treated rats were similar to the controls, suggesting that vitamin D treatment is able to reduce renal damage. PMID:26293661

  17. 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.

  18. Hepatic ultrasonographic findings in experimental carbon tetrachloride intoxication of the dog.

    PubMed

    Vörös, K; Albert, M; Vetési, F; Harmat, G y; Binder, K; Szaniszló, F

    1997-01-01

    An experimental study was undertaken in dogs with carbon tetrachloride (CCl4) intoxication to describe and follow the changes in the ultrasound appearance of the liver. Characteristic ultrasound features (enlarged liver, increased echogenicity with fine, tightly-packed echoes, and loss of echogenicity of the portal vein walls) were seen from day 2 of the experiment, culminating between days 2 and 7. Subsequently the liver gradually and almost completely regained its normal ultrasound appearance. Ultrasonographic findings corresponded to the severity of the clinicopathological parameters, and changed parallel with the results of liver biopsies. Histology of the biopsy samples revealed acute centrolobular lipid accumulation with necrobiosis and necrosis in the hepatocytes in the first stage of the disease. In the second stage, a secondary reparatory-inflammatory process and reparation in the interstitial tissue were seen. In some dogs, ill-defined hyperechoic foci were observed within the liver during the regenerative phase. Hepatic ultrasonography seems to be a reliable and relatively sensitive method for monitoring liver dystrophy with necrobiosis and lipid accumulation and to follow the course of steatosis in clinical cases. Ultrasound-guided biopsy can further improve the diagnostic accuracy of ultrasonography in liver dystrophy. PMID:9270137

  19. Hepatoprotective and antioxidant effect of tender coconut water on carbon tetrachloride induced liver injury in rats.

    PubMed

    Loki, Anthony Loperito; Rajamohan, T

    2003-10-01

    Hepatoprotective and antioxidant effects of tender coconut water (TCW) were investigated in carbon tetrachloride (CCl4)-intoxicated female rats. Liver damage was evidenced by the increased levels of serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) and decreased levels of serum proteins and by histopathological studies in CCl4-intoxicated rats. Increased lipid peroxidation was evidenced by elevated levels of thiobarbituric acid reactive substance (TBARS) viz, malondialdehyde (MDA), hydroperoxides (HP) and conjugated dienes (CD), and also by significant decrease in antioxidant enzymes activities, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx) and glutathione reductase (GR) and also reduced glutathione (GSH) content in liver. On the other hand, CCl4-intoxicated rats treated with TCW retained almost normal levels of these constituents. Decreased activities of antioxidant enzymes in CCl4-intoxicated rats and their reversal of antioxidant enzyme activities in TCW treated rats, shows the effectiveness of TCW in combating CCl4-induced oxidative stress. Hepatoprotective effect of TCW is also evidenced from the histopathological studies of liver, which did not show any fatty infiltration or necrosis, as observed in CCl4-intoxicated rats. PMID:22900330

  20. 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

  1. 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.

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

    PubMed

    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 (ATCC 29683). Complete transformation of 470 microM (72 mg/liter [aqueous]) CT was achieved by A. woodii within 2.5 days, when 10 microM OH-Cbl was added along with 25.2 mM fructose. This was approximately 30 times faster than A. woodii cultures (live or autoclaved) 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 [(14)C]CT transformed to (14)CO(2) (up to 31%) and (14)C-labeled soluble materials (principally L-lactate and acetate), while decreasing the percentage of CT reduced to chloroform and abiotically transformed to carbon disulfide. (14)CS(2) represented more than 35% of the [(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(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. PMID:10508086

  3. Reductive dehalogenation of hexachloroethane, carbon tetrachloride, and bromoform by anthrahydroquinone disulfonate and humic acid

    USGS Publications Warehouse

    Curtis, G.P.; Reinhard, M.

    1994-01-01

    The reductive dehalogenation of hexachloroethane (C2Cl6), carbon tetrachloride (CCl4), and bromoform (CHBr3) was examined at 50??C in aqueous solutions containing either (1) 500 ??M of 2,6-anthrahydroquinone disulfonate (AHQDS), (2) 250 ??M Fe2+, or (3) 250 ??M HS-. The pH ranged from 4.5 to 11.5 for AHQDS solutions and was 7.2 in the Fe2+ solutions and 7.8 in the HS- solutions. The observed disappearance of C2Cl6 in the presence of AHQDS was pseudo-first-order and fit k??ccl4 = k0[A(OH)2] + k1[A(OH)O-] + k2[A(O)22-] where A(OH)2, A(OH)O-, and A(O)22- represent the concentrations of the three forms of the AHQDS in solution. The values of k0, k1, and k2 were ???0,0.031, and 0.24 M-1 s-1, respectively. The addition of 25 mg of C/L of humic acid or organic matter extracted from Borden aquifer solids to aqueous solutions containing 250 ??M HS- or Fe2+ increased the reduction rate by factors of up to 10. The logarithms of the rate constants for the disappearance of C2Cl6 and CCl4 in seven different experimental systems were significantly correlated; log k???ccl4 = 0-64 log k??? c2cl6 - 0.83 with r2 = 0.80. The observed trend in reaction rates of C2Cl6 > CCl4 > CHBr3 is consistent with a decreasing trend in one-electron reduction potentials. ?? 1994 American Chemical Society.

  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. 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. PMID:25958928

  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. Carbon tetrachloride-mediated lipid peroxidation induces early mitochondrial alterations in mouse liver.

    PubMed

    Knockaert, Laetitia; Berson, Alain; Ribault, Catherine; Prost, Pierre-Emmanuel; Fautrel, Alain; Pajaud, Julie; Lepage, Sylvie; Lucas-Clerc, Catherine; Bégué, Jean-Marc; Fromenty, Bernard; Robin, Marie-Anne

    2012-03-01

    Although carbon tetrachloride (CCl(4))-induced acute and chronic hepatotoxicity have been extensively studied, little is known about the very early in vivo effects of this organic solvent on oxidative stress and mitochondrial function. In this study, mice were treated with CCl(4) (1.5 ml/kg ie 2.38 g/kg) and parameters related to liver damage, lipid peroxidation, stress/defense and mitochondria were studied 3 h later. Some CCl(4)-intoxicated mice were also pretreated with the cytochrome P450 2E1 inhibitor diethyldithiocarbamate or the antioxidants Trolox C and dehydroepiandrosterone. CCl(4) induced a moderate elevation of aminotransferases, swelling of centrilobular hepatocytes, lipid peroxidation, reduction of cytochrome P4502E1 mRNA levels and a massive increase in mRNA expression of heme oxygenase-1 and heat shock protein 70. Moreover, CCl(4) intoxication induced a severe decrease of mitochondrial respiratory chain complex IV activity, mitochondrial DNA depletion and damage as well as ultrastructural alterations. Whereas DDTC totally or partially prevented all these hepatic toxic events, both antioxidants protected only against liver lipid peroxidation and mitochondrial damage. Taken together, our results suggest that lipid peroxidation is primarily implicated in CCl(4)-induced early mitochondrial injury. However, lipid peroxidation-independent mechanisms seem to be involved in CCl(4)-induced early hepatocyte swelling and changes in expression of stress/defense-related genes. Antioxidant therapy may not be an efficient strategy to block early liver damage after CCl(4) intoxication. PMID:22157718

  8. Andrographis paniculata ameliorates carbon tetrachloride (CCl(4))-dependent hepatic damage and toxicity: diminution of oxidative stress.

    PubMed

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

    2011-01-01

    Andrographis paniculata (hempedu bumi) is a plant that possesses many medicinal values in treating several diseases and for health care maintenance. However, its hepatoprotective activity and mechanism of action have not been fully investigated. Therefore, this study aimed to evaluate the hepatoprotective effects of A. paniculata and its mechanism of action in rats. Carbon tetrachloride (CCl(4)) challenge of rats at a dose of 1.2 ml/kg body weight-induced oxidative stress in the liver. This was evidenced by augmentation in lipid peroxidation, which was accompanied by a decrease in the activities of antioxidant enzymes and depletion in the level of reduced glutathione (P < 0.05). Parrallel to these changes, CCl(4) challenge too, enhanced hepatic damage as evidenced by sharp increase in serum transaminases (e.g. alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase) (P < 0.05). Additionally, the impairment of liver function corresponded to histolopathological changes. However, most of these changes were reversed in a dose-dependent fashion by pre-treatment of animals with A. paniculata (P < 0.05). The ability of A. paniculata to scavenge the 2,2-Diphenyl-2-picrylhydrazyl radical was determined through its EC(50) value. The EC(50) value of A. paniculata was 583.60 ± 4.25 µg/ml. In addition, A. paniculata was found to contain 65.37 ± 1.20 mg/g total phenolics expressed as gallic acid equivalent. From these studies, it is concluded that A. paniculata could be used as a hepatoprotective agent and possesses the potential to treat or prevent degenerative diseases where oxidative stress is implicated. PMID:21801496

  9. 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

  10. Transformation of carbon tetrachloride in the presence of sulfide, biotite, and vermiculite

    SciTech Connect

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

    1992-01-01

    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 80-85% of the CCl4 was transformed to CO2 via the measured intermediate, CS2. Chloroform comprised 5-15% of the products. The remaining 5% of the products were an unidentified non-volatile compound and CO. At 25C, the half-life of CCl4 with 1 mM HS was calculated to be 2600, 160, and 50 days for the homogeneous, vermiculite (114 sq m/L), and biotite (55.8 sq m/L) systems, respectively. The CCl4 transformation rate was found to be dependent on the type and quantity of the solid and the temperature, but was independent of pH and HS(-) concentration above a critical HS(-) concentration. The activation energies (+ or - 95% confidence intervals) were determined to be 122 + or - 32, 91.3 + or - 8.4, and 59.9 + or - 13.3 kJ/mol for the homogeneous, vermiculite, and biotite systems, respectively. The CCl4 transformation rate exhibited first-order behavior with respect to biotite surface area concentration SC(sub biotite) below 55.8 sq m/L. The rate of CCl4 transformation was independent of HS(-) concentration when (HS(-)) = 0.5-4 mM and SC(sub biotite) = 55.8 sq m/L. Below (HS(-)) = 0.5-4 mM, the rate law was dependent on HS(-) concentration.

  11. 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.

  12. 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

  13. PEGylated lactoferrin enhanced its hepatoprotective effects on acute liver injury induced by carbon tetrachloride in rats.

    PubMed

    Sugiyama, Akihiko; Sato, Atsushi; Takeuchi, Takashi

    2009-07-01

    Polyethylene glycol (PEG) is attached to proteins in order to increase their half-life in circulation and reduce their immunogenicity in vivo. The present study was conducted to examine whether two different sizes of PEGylated bovine lactoferrin (40k-PEG-bLf and 20k-PEG-bLf) would enhance the protective effect of native bLf on liver injury induced by carbon tetrachloride (CCl(4)) in rats. Silymarin, a known hepatoprotective drug was used as a positive control. Compared to native bLf, the treatment of PEGylated bLf more markedly prevented the elevation of serum levels of hepatic enzyme markers and inhibited fatty degeneration and the hepatic necrosis induced by CCl(4). 40k-PEG-bLf showed a more significant suppressive effect on CCl(4)-induced hepatic injury than 20k-PEG-bLf. The treatment with PEGylated bLf elevated serum SOD activity reduced by CCl(4) more significantly than native bLf. 40k-PEG-bLf enhanced serum SOD activity more significantly than 20k-PEG-bLf. Immunohistochemical study showed that the PEGylation of bLf enhanced its intracellular transportation to hepatocytes. The increases in intracellular transportation of the PEGylated bLf in order were: 40k-PEG-bLf>20k-PEG-bLf>native bLf. These findings suggested that the mechanism of the enhancement of hepatoprotective effect by PEGylated bLf was associated with an increase in the intracellular transportation of PEGylated bLf in hepatocytes. PMID:19341777

  14. Reductive Dechlorination of Carbon Tetrachloride by Soil With Ferrous and Bisulfide

    NASA Astrophysics Data System (ADS)

    Choi, K.; Lee, W.

    2008-12-01

    Batch and column experiments were conducted to investigate the effect of concentration of reductants, contact time to activate reductive capacity, and pH on reductive dechlorination by soil with Fe(II) and HS- in this study. Carbon tetrachloride (CT) was used as a representative target organic compound. Sorption kinetic and isotherm tests were performed to investigate the influence of adsorption on the soil surface. Target compound in the soil suspension reached sorption equilibrium in 4 hours and the type of isotherm was well fitted by a linear type isotherm. In batch experiment, kinetic rate constants for the reductive dechlorination of CT increased with increasing the concentration of the reductants (Fe(II) and HS-). However, Fe(II) was a much more effective reductant, producing higher k values than those of HS-. The contact time of one day for the soil with HS- and that of four hours with Fe(II) showed the highest reaction rates. Additionally, the rate constants increased with the increase of pH in soil suspension with Fe(II) (5.2~8) and HS- (8.3~10.3), respectively. In column experiment, the soil column with Fe(II) showed larger bed volumes (13.76) to reach a column breakthrough than that with HS- indicating the treatment of Fe(II) is more effective for the reductive dechlorination of CT. To enhance reductive capacity of soil column under an acidic condition, CaO addition to the column treated with Fe(II) showed better results for the reductive dechlorination of CT than that of HS-. Fe(II) showed better CT dechlorination than HS- in batch and column reactors therefore, it can be used as an effective reducing agent for the treatment of soil contaminated with chlorinated organic compounds.

  15. Degradation of carbon tetrachloride by iron metal: Complexation effects on the oxide surface

    NASA Astrophysics Data System (ADS)

    Johnson, Timothy L.; Fish, William; Gorby, Yuri A.; Tratnyek, Paul G.

    1998-03-01

    Dehalogenation of chlorinated aliphatic contaminants at the surface of zero-valent iron metal (Fe 0) is mediated by the thin film of iron (hydr)oxides found on Fe 0 under environmental conditions. To evaluate the role this oxide film plays in the reduction of chlorinated methanes, carbon tetrachloride (CCl 4) degradation by Fe 0 was studied under the influence of various anions, ligands, and initial CCl 4 concentrations ([ P] o). Over the range of conditions examined in these batch experiments, the reaction kinetics could be characterized by surface-area-normalized rate constants that were pseudo-first order for CCl 4 disappearance ( kCCl 4), and zero order for the appearance of dissolved Fe 2+ ( kFe 2+). The rate of dechlorination exhibits saturation kinetics with respect to [ P] o, suggesting that CCl 4 is transformed at a limited number of reactive surface sites. Because oxidation of Fe 0 by CCl 4 is the major corrosion reaction in these systems, kFe 2+ also approaches a limiting value at high CCl 4 concentrations. The adsorption of borate strongly inhibited reduction of CCl 4, but a concomitant addition of chloride partially offset this effect by destabilizing the film. Redox active ligands (catechol and ascorbate), and those that are not redox active (EDTA and acetate), all decreased kCCl 4 (and kFe 2+). Thus, it appears that the relatively strong complexation of these ligands at the oxide-electrolyte interface blocks the sites where weak interactions with the metal oxide lead to dehalogenation of chlorinated aliphatic compounds.

  16. Chlordecone potentiates hepatic fibrosis in chronic liver injury induced by carbon tetrachloride in mice.

    PubMed

    Tabet, Elise; Genet, Valentine; Tiaho, François; Lucas-Clerc, Catherine; Gelu-Simeon, Moana; Piquet-Pellorce, Claire; Samson, Michel

    2016-07-25

    Chronic liver damage due to viral or chemical agents leads to a repair process resulting in hepatic fibrosis. Fibrosis may lead to cirrhosis, which may progress to liver cancer or a loss of liver function, with an associated risk of liver failure and death. Chlordecone is a chlorinated pesticide used in the 1990s. It is not itself hepatotoxic, but its metabolism in the liver triggers hepatomegaly and potentiates hepatotoxic agents. Chlordecone is now banned, but it persists in soil and water, resulting in an ongoing public health problem in the Caribbean area. We assessed the probable impact of chlordecone on the progression of liver fibrosis in the population of contaminated areas, by developing a mouse model of chronic co-exposure to chlordecone and a hepatotoxic agent, carbon tetrachloride (CCl4). After repeated administrations of chlordecone and CCl4 by gavage over a 12-week period, we checked for liver damage in the exposed mice, by determining serum liver transaminase (AST, ALT) levels, histological examinations of the liver and measuring the expression of genes encoding extracellular matrix components. The co-exposure of mice to CCl4 and chlordecone resulted in significant increases in ALT and AST levels. Chlordecone also increased expression of the Col1A2, MMP-2, TIMP-1 and PAI-1 genes in CCl4-treated mice. Finally, we demonstrated, by quantifying areas of collagen deposition and alpha-SMA gene expression, that chlordecone potentiated the hepatic fibrosis induced by CCl4. In conclusion, our data suggest that chlordecone potentiates hepatic fibrosis in mice with CCl4-induced chronic liver injury. PMID:26853152

  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. 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.

  19. 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

  20. Protective effect of L-theanine on carbon tetrachloride-induced acute liver injury in mice.

    PubMed

    Jiang, Wei; Gao, Min; Sun, Shuai; Bi, Aijing; Xin, Yinqiang; Han, Xiaodong; Wang, Liangbin; Yin, Zhimin; Luo, Lan

    2012-06-01

    We studied effects of L-theanine, a unique amino acid in tea, on carbon tetrachloride (CCl(4))-induced liver injury in mice. The mice were pre-treated orally with L-theanine (50, 100 or 200 mg/kg) once daily for seven days before CCl(4) (10 ml/kg of 0.2% CCl(4) solution in olive oil) injection. L-theanine dose-dependently suppressed the increase of serum activity of ALT and AST and bilirubin level as well as liver histopathological changes induced by CCl(4) in mice. L-theanine significantly prevented CCl(4)-induced production of lipid peroxidation and decrease of hepatic GSH content and antioxidant enzymes activities. Our further studies demonstrated that L-theanine inhibited metabolic activation of CCl(4) through down-regulating cytochrome P450 2E1 (CYP2E1). As a consequence, L-theanine inhibited oxidative stress-mediated inflammatory response which included the increase of TNF-α and IL-1β in sera, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in livers. CCl(4)-induced activation of apoptotic related proteins including caspase-3 and PARP in mouse livers was also prevented by L-theanine treatment. In summary, L-theanine protects mice against CCl(4)-induced acute liver injury through inhibiting metabolic activation of CCl(4) and preventing CCl(4)-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis. PMID:22583898

  1. 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.

  2. Hepatoprotective effect of Scoparia dulcis on carbon tetrachloride induced acute liver injury in mice.

    PubMed

    Tsai, Jen-Chieh; Peng, Wen-Huang; Chiu, Tai-Hui; Huang, Shun-Chieh; Huang, Tai-Hung; Lai, Shang-Chih; Lai, Zhen-Rung; Lee, Chao-Ying

    2010-01-01

    This study aims to investigate the hepatoprotective activity and active constituents of the ethanol extract of Scoparia dulcis (SDE). The hepatoprotective effect of SDE (0.1, 0.5 and 1 g/kg) was evaluated on the carbon tetrachloride (CCl(4))-induced acute liver injury. The active constituents were detected by high performance liquid chromatography (HPLC). Mice pretreated orally with SDE (0.5 and 1.0 g/kg) and silymarin (200 mg/kg) for five consecutive days before the administering of a single dose of 0.2% CCl(4) (10 ml/kg of bw, ip) showed a significant inhibition of the increase of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histological analyses also showed that SDE (0.5 and 1.0 g/kg) and silymarin reduced the extent of liver lesions induced by CCl(4), including vacuole formation, neutrophil infiltration and necrosis. Moreover, SDE decreased the malondialdehyde (MDA) level and elevated the content of reduced glutathione (GSH) in the liver as compared to those in the CCl(4) group. Furthermore, SDE (0.5 and 1.0 g/kg) enhanced the activities of anti-oxidative enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRd) and glutathione-S-transferase (GST). The quantities of active constituents in SDE were about 3.1 mg luteolin/g extract and 1.1 mg apigenin/g extract. The hepatoprotective mechanisms of SDE were likely associated to the decrease in MDA level and increase in GSH level by increasing the activities of antioxidant enzymes such as SOD, GPx, GRd and GST. These results demonstrated that SDE could alleviate CCl(4)-induced acute liver injury in mice. PMID:20626061

  3. Amelioration of carbon tetrachloride-induced pulmonary toxicity with Oxalis corniculata.

    PubMed

    Ahmad, Bushra; Khan, Muhammad Rashid; Shah, Naseer Ali

    2015-12-01

    This research work was planned to investigate the antioxidant potential of methanolic crude extract of Oxalis corniculata (OCME) against lung injuries initiated by carbon tetrachloride (CCl4) in rats at histological and biochemical level. A total of 42 female Sprague Dawley rats were randomly distributed in to seven groups and each group comprised of six rats. Experiment was completed in 22 days (10 doses at alternate days). Group I was not treated (control rats), while group II was administered with vehicles (olive oil and dimethyl sulfoxide), groups III, IV, and V were treated with 1 ml kg(-1) body weight (b.w.) of CCl4 (20% in olive oil). Group III received only CCl4, whereas groups IV and V were administered with 100 and 200 mg kg(-1) b.w. of OCME, respectively. Group VI was administered with OCME (200 mg kg(-1) b.w.) alone. Group VII was treated with sylimarin (50 mg kg(-1) b.w.). CCl4 enhanced the lipid peroxidation while reduced the glutathione in lung samples. Activities of antioxidant enzymes, catalase, peroxidase, superoxide dismutase, and glutathione-S-transferase decreased in lung homogenates with CCl4. Treatment of CCl4 induced deleterious changes in the microanatomy of lungs by rupturing the alveolar septa, thickening of alveolar walls, and damaging the cells with subsequent collapse of blood vessels due to the accumulation of degenerated blood cells. OCME, dose dependently, prevented the alterations in these parameters. These results suggest that OCME protected the lungs due to its intrinsic properties by scavenging of free radicals generated by CCl4. PMID:23796759

  4. Protective Effects of Vitamin E Analogs against Carbon Tetrachloride-Induced Fatty Liver in Rats

    PubMed Central

    Yachi, Rieko; Igarashi, Osamu; Kiyose, Chikako

    2010-01-01

    Recently, it has been reported that α-tocopherol (α-Toc) is effective for amelioration of liver damage. However, it is unknown whether other vitamin E analogs are effective. In this study, we investigated the effects of γ-tocopherol (γ-Toc) and tocotrienols (T3) in rats with fatty liver. Rats fed a vitamin E-deficient diet for four weeks were divided into eight groups: Control, carbon tetrachloride (CCl4), α-Toc, α-Toc + CCl4, γ-Toc, γ-Toc + CCl4, T3 mix, T3 mix + CCl4. After a 24 h fast, the rats were administered 20 mg of each of the vitamin E analogs, respectively. Moreover, the CCl4 group were given 0.5 ml/kg body weight corn oil preparation containing CCl4 6 h after vitamin E administration. We measured the activities of aspartate aminotransferase and alanine aminotransferase (ALT) in plasma, and the contents of triglyceride (TG), total cholesterol (T-Chol) and vitamin E analogs in the liver. Also, we determined the hepatic expression of mRNA for inflammatory cytokines. The liver TG content in the γ-Toc + CCl4 and T3 mix + CCl4 groups was decreased in comparison with the CCl4 group. Moreover, ALT activity in the T3 mix + CCl4 group was significantly lower than CCl4 group. These findings suggest that γ-Toc and T3 are effective for amelioration of fatty liver. PMID:20838570

  5. Melatonin enhances mitophagy and mitochondrial biogenesis in rats with carbon tetrachloride-induced liver fibrosis.

    PubMed

    Kang, Jung-Woo; Hong, Jeong-Min; Lee, Sun-Mee

    2016-05-01

    Liver fibrosis leads to liver cirrhosis and failure, and no effective treatment is currently available. Growing evidence supports a link between mitochondrial dysfunction and liver fibrogenesis and mitochondrial quality control-based therapy has emerged as a new therapeutic target. We investigated the protective mechanisms of melatonin against mitochondrial dysfunction-involved liver fibrosis, focusing on mitophagy and mitochondrial biogenesis. Rats were treated with carbon tetrachloride (CCl4 ) dissolved in olive oil (0.5 mL/kg, twice a week, i.p.) for 8 wk. Melatonin was administered orally at 2.5, 5, and 10 mg/kg once a day. Chronic CCl4 exposure induced collagen deposition, hepatocellular damage, and oxidative stress, and melatonin attenuated these increases. Increases in mRNA and protein expression levels of transforming growth factor β1 and α-smooth muscle actin in response to CCl4 were attenuated by melatonin. Melatonin attenuated hallmarks of mitochondrial dysfunction, such as mitochondrial swelling and glutamate dehydrogenase release. Chronic CCl4 exposure impaired mitophagy and mitochondrial biogenesis, and melatonin attenuated this impairment, as indicated by increases in mitochondrial DNA and in protein levels of PTEN-induced putative kinase 1 (PINK1); Parkin; peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α); nuclear respiratory factor 1 (NRF1); and transcription factor A, mitochondrial (TFAM). CCl4 -mediated decreases in mitochondrial fission- and fusion-related proteins, such as dynamin-related protein 1 (DRP1) and mitofusin 2, were also attenuated by melatonin. Moreover, melatonin induced AMP-activated protein kinase (AMPK) phosphorylation. These results suggest that melatonin protects against liver fibrosis via upregulation of mitophagy and mitochondrial biogenesis, and may be useful as an anti-fibrotic treatment. PMID:26882442

  6. Role of the Sympathetic Nervous System in Carbon Tetrachloride-Induced Hepatotoxicity and Systemic Inflammation

    PubMed Central

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

    2015-01-01

    Carbon tetrachloride (CCl4) is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS) in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL)-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2), and tumor necrosis factor-α (TNF-α)], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response. PMID:25799095

  7. 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

  8. 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.

  9. 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

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

    PubMed

    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 1930days. Initially the column was continuously fed synthetic groundwater with PCE (0.1mM), sulfate (SO4(2-)) (0.2mM) and formate (2.1mM) or lactate (1.1mM), but not CT. In these early stages of the study the effluent H2 concentrations ranged from 7 to 19nM, and PCE was transformed to ethene (ETH) (81 to 85%) and vinyl chloride (VC) (11 to 17%), and SO4(2-) was completely reduced when using either lactate or formate as electron donors. SO4(2-) 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 (0.015mM) 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 160nM 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 1nM. Under these conditions both SO4(2-) 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 40nM, and complete SO4(2-) 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. PMID:27183341

  11. 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.

  12. 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.

  13. Ameliorative effect of Ganoderma lucidum on carbon tetrachloride-induced liver fibrosis in rats

    PubMed Central

    Lin, Wen-Chuan; Lin, Wei-Lii

    2006-01-01

    AIM: To investigate the effects of Reishi mushroom, Ganoderma lucidum extract (GLE), on liver fibrosis induced by carbon tetrachloride (CCl4) in rats. METHODS: Rat hepatic fibrosis was induced by CCl4. Forty Wistar rats were divided randomly into 4 groups: control, CCl4, and two GLE groups. Except for rats in control group, all rats were administered orally with CCl4 (20%, 0.2 mL/100 g body weight) twice a week for 8 weeks. Rats in GLE groups were treated daily with GLE (1 600 or 600 mg/kg) via gastrogavage throughout the whole experimental period. Liver function parameters, such as ALT, AST, albumin, and albumin/globulin (A/G) ratio, spleen weight and hepatic amounts of protein, malondiladehyde (MDA) and hydroxyproline (HP) were determined. Histochemical staining of Sirius red was performed. Expression of transforming growth factor β1 (TGF-β1), methionine adenosyltransferase (MAT1) 1A and MAT2A mRNA were detected by using RT-PCR. RESULTS: CCl4 caused liver fibrosis, featuring increase in plasma transaminases, hepatic MDA and HP contents, and spleen weight; and decrease in plasma albumin, A/G ratio and hepatic protein level. Compared with CCl4 group, GLE (600, 1 600 mg/kg) treatment significantly increased plasma albumin level and A/G ratio (P  < 0.05) and reduced the hepatic HP content (P < 0.01). GLE (1 600 mg/kg) treatment markedly decreased the activities of transaminases (P  < 0.05), spleen weight (P  < 0.05) and hepatic MDA content (P  < 0.05); but increased hepatic protein level (P  < 0.05). Liver histology in the GLE (1 600 mg/kg)-treated rats was also improved (P  < 0.01). RT-PCR analysis showed that GLE treatment decreased the expression of TGF-β1 (P  < 0.05-0.001) and changed the expression of MAT1A (P  < 0.05-0.01) and MAT2A (P  < 0.05-0.001). CONCLUSION: Oral administration of GLE significantly reduces CCl4-induced hepatic fibrosis in rats, probably by exerting a protective effect against hepatocellular

  14. 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).

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. Alcohol/"low-dose" carbon tetrachloride-induced cirrhosis in rats using different methods of alcohol feeding.

    PubMed

    Plummer, J L; Hall, P D; Cmielewski, P L; Iisley, A H; Ahem, M J

    1994-12-01

    Cirrhosis may be reliably produced in rats by exposing them to low levels of carbon tetrachloride vapor while feeding alcohol in the Lieber-DeCarli liquid diet. This study aimed to determine whether alternative cheaper and more convenient ways of feeding alcohol would also allow the production of cirrhosis. Animals were fed alcohol in the Lieber-DeCarli diet, in a gel diet, or by addition of alcohol + sucrose to their drinking water, and were exposed to carbon tetrachloride vapor 6 hr/night, 5 nights/week. After 12 weeks of treatment, all animals (4 of 4) receiving alcohol in the Lieber-DeCarli diet, but only two in each of the gel and drinking water groups, were cirrhotic. The variable results with the gel diet may be due to loss of alcohol by evaporation from the gel. Alcohol intake in the group receiving alcohol in drinking water was greater than in those receiving Lieber-DeCarli diet. We suggest that the increased carbohydrate intake due to addition to sucrose to the water exerted a protective effect on the liver. PMID:7695051

  2. Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4) Treated Rats

    PubMed Central

    Chowdhury, Mohammed Riaz Hasan; Sagor, Md Abu Taher; Tabassum, Nabila; Potol, Md Abdullah

    2015-01-01

    Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (−)-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4) treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA), nitric oxide, advanced protein oxidation products level (APOP), and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level) and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats. PMID:26106435

  3. Effect of apitherapy formulations against carbon tetrachloride-induced toxicity in Wistar rats after three weeks of treatment.

    PubMed

    Andritoiu, Calin Vasile; Ochiuz, Lacramioara; Andritoiu, Vasile; Popa, Marcel

    2014-01-01

    The human body is exposed nowadays to increasing attacks by toxic compounds in polluted air, industrially processed foods, alcohol and drug consumption that increase liver toxicity, leading to more and more severe cases of hepatic disorders. The present paper aims to evaluate the influence of the apitherapy diet in Wistar rats with carbon tetrachloride-induced hepatotoxicity, by analyzing the biochemical determinations (enzymatic, lipid and protein profiles, coagulation parameters, minerals, blood count parameters, bilirubin levels) and histopathological changes at the level of liver, spleen and pancreas. The experiment was carried out on six groups of male Wistar rats. Hepatic lesions were induced by intraperitoneal injection of carbon tetrachloride (dissolved in paraffin oil, 10% solution). Two mL per 100 g were administered, every 2 days, for 2 weeks. Hepatoprotection was achieved with two apitherapy diet formulations containing honey, pollen, propolis, Apilarnil, with/without royal jelly. Biochemical results reveal that the two apitherapy diet formulations have a positive effect on improving the enzymatic, lipid, and protein profiles, coagulation, mineral and blood count parameters and bilirubin levels. The histopathological results demonstrate the benefits of the two apitherapy diet formulations on reducing toxicity at the level of liver, spleen and pancreas in laboratory animals. PMID:25178061

  4. Transcriptome Analysis of the Effects of Gomisin A on the Recovery of Carbon Tetrachloride-Induced Damage in Rat Liver

    PubMed Central

    Choi, Young Mi; Choi, In Soo; Lee, Sang Mong; Hwang, Dae Youn; Choi, Young Whan

    2011-01-01

    Gomisin A possesses a hepatic function-facilitating property in liver-injured rats. Its preventive action on carbon tetrachloride-induced cholestasis is due to maintenance of the function of the bile acids-independent fraction. To investigate alterations in gene expression after gomisin A treatment on injured rat liver, DNA microarray analyses were performed on a Rat 44K 4-Plex Gene Expression platform with duplicated reactions after gomisin A treatment. We identified 255 up-regulated and 230 down-regulated genes due to the effects of gomisin A on recovery of carbon tetrachloride-induced rat liver damage. For functional characterization of these genes, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes biochemical pathways analyses were performed. Many up-regulated or down-regulated genes were related to cell cycle or focal adhesion and cell death genes, respectively. Our microarray experiment indicated that the liver repair mechanism induced by gomisin A was strongly associated with increased gene expressions related to cell cycle and suppression of the gene expression related in cell death. PMID:21826177

  5. Fluorescence quenching of biologically active carboxamide by aniline and carbon tetrachloride in different solvents using Stern-Volmer plots

    NASA Astrophysics Data System (ADS)

    Patil, N. R.; Melavanki, R. M.; Kapatkar, S. B.; Chandrashekhar, K.; Patil, H. D.; Umapathy, Siva

    2011-09-01

    Fluorescence quenching of biologically active carboxamide namely (E)-2-(4-chlorobenzylideneamino)-N-(2-chlorophenyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide [ECNCTTC] by aniline and carbon tetrachloride (CCl 4) quenchers in different solvents using steady state method and time resolved method using only one solvent has been carried out at room temperature to understand the role of quenching mechanisms. The Stern-Volmer plot has been found to be linear for all the solvents studied. The probability of quenching per encounter p ( p') was determined in all the solvents and was found to be less than unity. Further, from the studies of rate parameters and life time measurements in n-heptane and cyclohexane with aniline and carbon tetrachloride as quenchers have been shown that, the phenomenon of quenching is generally governed by the well-known Stern-Volmer (S-V) plot. The activation energy Ea (or Ea) of quenching was determined using the literature values of activation energy of diffusion Ed and the experimentally determined values of p (or p'). It has been found that, the activation energy Ea(Ea) is greater than the activation energy for diffusion Ed in all solvents. Hence, from the magnitudes of Ea (or Ea) as well as p (or p') infer that, the quenching mechanism is not solely due to the material diffusion, but there is also contribution from the activation energy.

  6. 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.

  7. 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.

  8. EFFECT OF GAVAGE VEHICLE ON HEPATOTOXICITY OF CARBON TETRACHLORIDE IN CD-1 MICE: CORN OIL VERSUS TWEEN-60 AQUEOUS EMULSION (JOURNAL VERSION)

    EPA Science Inventory

    The investigation was conducted to evaluate the effect of corn oil gavage on the subchronic hepatotoxicity of carbon tetrachloride (CCl(4)). Male and female CD-1 mice were gavaged with 0, 1.2, 12, and 120 mg/kg CCl(4) in either corn oil or 1% Tween-60 vehicles once daily for five...

  9. 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

  10. Physiologically based pharmacokinetic/pharmacodynamic modeling of the toxicologic interaction between carbon tetrachloride and Kepone.

    PubMed

    el-Masri, H A; Thomas, R S; Sabados, G R; Phillips, J K; Constan, A A; Benjamin, S A; Andersen, M E; Mehendale, H M; Yang, R S

    1996-01-01

    Carbon tetrachloride (CCl4) lethality in Sprague-Dawley rats is greatly amplified by pretreatment of Kepone (decachlorooctahydro-1,3,2-metheno-2H-cyclobuta[cd] pentalen-2-one). The increase in lethality was attributed to the obstruction of liver regenerative processes. These processes are essential for restoring the liver to its full functional capacity following injury by CCl4. Based on the available mechanistic information on Kepone/CCl4 interaction, a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model was constructed where the following effects of Kepone on CCl4 toxicity are incorporated: (1) inhibition of mitosis; (2) reduction of repair mechanism of hepatocellular injury; (3) suppression of phagocytosis. The PBPK/PD model provided computer simulation consistent with previously published time-course results of hepatotoxicity (i.e., pyknotic, injured and mitotic cells) of CCl4 with or without Kepone. As a further verification of this model, the computer simulations were also consistent with exhalation kinetic data for rats injected with different intraperitoneal (i.p.) doses of CCl4 in our laboratory. Subsequently, the PBPK/PD model, coupled with Monte Carlo simulation, was used to predict lethalities of rats treated with CCl4 alone and CCl4 in combination with Kepone. The experimental lethality studies performed in our laboratories were as follows: Sprague-Dawley rats were given either control diet or diet containing 10 ppm Kepone for 15 days. On day 16, rats in the Kepone treated group were given i.p. doses of 0, 10, 50, and 100 microliters/kg CCl4 (n = 9) while control rats were exposed to 0, 100, 1000, 3000, and 6000 microliters/kg CCl4 (n = 9). Lethality was observed at the 1000 (1/9), 3000 (4/9), and 6000 (8/9) microliters/kg doses for the control group and at the 50 (4/9) and 100 (8/9) microliters/kg for the treated group. Based on Monte Carlo simulation, which was used to run electronically 1000 lethality experiments for each dosing

  11. 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

  12. Hepatoprotective Activity of the Ethanolic Extract of Ficus caricaLinn. LeavesinCarbon Tetrachloride-Induced Hepatotoxicityin Rats

    PubMed Central

    Mujeeb, Mohd; Alam Khan, Shah; Aeri, Vidhu; Ali, Babar

    2011-01-01

    The ethanolic extract of Ficus carica leaves was screened for hepatoprotective and antioxidant activity in hepatotoxic Albino rats induced via carbon tetrachloride. The degree of protection was measured by estimating biochemical parameters such as serum glutamate Oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase ( SGPT),totalprotein (TP), totalalbumin (TA), alkaline phosphatase (ALKP) and the level of total serum bilirubin. The extract in addition reduced CCl4 induced lipid peroxidation in-vivo and in-vitro. The ethanolic extract (50 mg/kg, 100mg/kg,200mg/kg)exhibited significant hepatoprotection incarbontetra chloride in toxicated rats in a dose dependant manner. The hepatoprotective effects of the extract were comparable with the standard drug silymarin 10)mg/kg body weight, IP). PMID:24250358

  13. Antioxidant and hepatoprotective activity of punicalagin and punicalin on carbon tetrachloride-induced liver damage in rats.

    PubMed

    Lin, C C; Hsu, Y F; Lin, T C; Hsu, F L; Hsu, H Y

    1998-07-01

    Punicalagin and punicalin, isolated from the leaves of Terminalia catappa L., are used to treat dermatitis and hepatitis. Both compounds have strong antioxidative activity. The antihepatotoxic activity of punicalagin and punicalin on carbon tetrachloride (CCl4)-induced toxicity in the rat liver was evaluated. Levels of serum glutamate-oxalate-transaminase and glutamate-pyruvate-trans-aminase were increased by administration of CCl4 and reduced by drug treatment. Histological changes around the liver central vein and oxidation damage induced by CCl4 also benefited from drug treatment. The results show that both punicalagin and punicalin have anti-hepatotoxic activity but that the larger dose of punicalin induced liver damage. Thus even if tannins have strong antioxidant activity at very small doses, treatment with a larger dose will induce cell damage. PMID:9720629

  14. 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

  15. Investigation of the hepatoprotective effects of Sesame (Sesamum indicum L.) in carbon tetrachloride-induced liver toxicity.

    PubMed

    Cengiz, Nureddin; Kavak, Servet; Güzel, Ali; Ozbek, Hanefi; Bektaş, Hava; Him, Aydın; Erdoğan, Ender; Balahoroğlu, Ragıb

    2013-01-01

    More than 600 chemicals can cause damage in liver, one of which is carbon tetrachloride (CCl₄). Hepatoprotective agents could prevent tissue damage and reduce morbidity and mortality rates; such agents may include alternative or folkloric treatments. We investigated sesame (Sesamum indicum L.) for its hepatoprotective effect in CCl₄-induced experimental liver damage. To this end, 0.8 mg/kg of sesame fixed oil was provided intraperitoneally to rats whose livers were damaged by CCl₄. Tissue and blood samples were taken at the end of the experiments and evaluated histologically and biochemically. Ballooning degenerations and an increase in lipid droplets in liver parenchyma and increases in serum alanine transaminase, aspartate transaminase, and bilirubin were found in the CCl₄ group. Biochemical and histopathological findings in the sesame fixed oil treated group were not significantly different from the CCl₄ group. Sesame did not show a hepatoprotective effect in CCl₄-induced liver toxicity. PMID:22915054

  16. Hepatoprotective Effect of Otostegia persica Boiss. Shoot Extract on Carbon Tetrachloride-Induced Acute Liver Damage in Rats

    PubMed Central

    Nasiri Bezenjani, Sedighe; Pouraboli, Iran; Malekpour Afshar, Reza; Mohammadi, Gholamabbas

    2012-01-01

    In this study, the hepatoprotective effect of the methanol extract of aerial parts (shoot) from Otostegia persica Boiss (Golder) was investigated against the carbon tetrachloride (CCl4)-induced acute hepatotoxicity in male rats. Liver damage was induced through the oral administration of 50% CCl4 in liquid paraffin (2.5 mL/Kg bw, per os) 60 min after the administration of the methanol extract of O. persica shoot (in 200, 300, 400 mg/Kg bw doses) and assessed using biochemical parameters (plasma and liver tissue malondialdehyde (MDA), transaminase enzyme levels in plasma [aspartate transaminase (AST), alanine aminotransferase (ALT)] and liver glutathione (GSH) levels). Results show that the methanol extract of O. persica shoot is active at 300 mg/Kg (per os) and it possess remarkable antioxidant and hepatoprotective activities. Additionally, histopathological studies verified the effectiveness of this dose of extract in acute liver damage prevention. PMID:24250558

  17. Hepatoprotective effect of grape seed oil against carbon tetrachloride induced oxidative stress in liver of γ-irradiated rat.

    PubMed

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

    2016-07-01

    Carbon tetrachloride (CCl4) and ionizing radiation are well known environmental pollutants that generate free radicals and induce oxidative stress. The liver is the primary and major target organ responsible for the metabolism of drugs, toxic chemicals and affected by irradiation. This study investigated the effect of grape seed oil (GSO) on acute liver injury induced by carbon tetrachloride (CCl4) in γ-irradiated rats (7Gy). CCl4-intoxicated rats exhibited an elevation of ALT, AST activities, IL-6 and TNF-α level in the serum. Further, the levels of MDA, NO, NF-κB and the gene expression of CYP2E1, iNOS and Caspase-3 were increased, and SOD, CAT, GSH-Px, GST activities and GSH content were decreased. Furthermore, silent information regulator protein 1 (SIRT1) gene expression was markedly down-regulated. Additionally, alterations of the trace elements; copper, manganese, zinc and DNA fragmentation was observed in the hepatic tissues of the intoxicated group. These effects were augmented in CCl4-intoxicated-γ-irradiated rats. However, the administration of GSO ameliorated these parameters. GSO exhibit protective effects on CCl4 induced acute liver injury in γ-irradiated rats that could be attributed to its potent antioxidant, anti-inflammatory and anti-apoptotic activities. The induction of the antioxidant enzymes activities, down-regulation of the CYP2E1, iNOS, Caspase-3 and NF-κB expression, up-regulation of the trace elements concentration levels and activation of SIRT1 gene expression are responsible for the improvement of the antioxidant and anti-inflammatory status in the hepatic tissues and could be claimed to be the hepatoprotective mechanism of GSO. PMID:27085796

  18. Antihepatofibrotic Effects of Aqueous Extract of Prunella vulgaris on Carbon Tetrachloride-Induced Hepatic Fibrosis in Rats.

    PubMed

    Hu, Yi-Xiang; Yu, Chen-Huan; Wu, Fang; Yu, Wen-Ying; Zhong, Yu-Sen; Ying, Hua-Zhong; Yu, Bing

    2016-01-01

    Prunella vulgaris has been widely used in the folk medicine of Northeastern Asian countries for the treatment of acute liver injury and infectious hepatitis. In the present study, the protective effect of aqueous extract from P. vulgaris was investigated on carbon tetrachloride-induced hepatic fibrosis in vivo. Our data showed that the administration of aqueous extract from P. vulgaris at doses of 50, 100, and 200 mg/kg significantly reduced the elevated serum levels of alanine aminotransferase, aspartate aminotransferase, type III precollagen, and hyaluronic acid in rats with hepatic fibrosis. In addition, aqueous extract from P. vulgaris also reduced the incidence of liver lesions and the formation of fibrous septa, and remarkably decreased the serum levels of inflammatory cytokines, platelet derived growth factor, interleukin-4, interleukin-8, and tumor necrosis factor alpha. Furthermore, aqueous extract from P. vulgaris significantly inhibited the activation of hepatic stellate cells by regulating the expression of α smooth muscle actin, transforming growth factor β 1, and smad2 and also decreased the deposition of extracellular matrix proteins via regulating the expressions of tissue inhibitor of metalloproteinase-1, matrix metalloproteinase-2,-13. Real-time polymerase chain reaction further revealed that post-treatment with aqueous extract from P. vulgaris decreased the elevated levels of miR-34a and miR-199a-5p in hepatic fibrosis rats. These results demonstrated that aqueous extract from P. vulgaris alleviates carbon tetrachloride-induced hepatic fibrosis by inhibiting the activation of hepatic stellate cells, promoting collagenolysis and regulating fibrosis-related microRNAs. PMID:26460672

  19. 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

  20. FINAL REPORT. REMOVAL OF TECHNETIUM, CARBON TETRACHLORIDE, AND METALS FROM DOE PROPERTIES

    EPA Science Inventory

    The basic objectives of our DOE-supported research were to develop simple chemical and materials approaches to the remediation of aqueous wastes. DOE properties and custodial properties contain groundwater and process streams with a variety of contaminants, including radionuclide...

  1. 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

  2. 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.

  3. 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

  4. Prevention of carbon tetrachloride (CCl4)-induced toxicity in testes of rats treated with Physalis peruviana L. fruit.

    PubMed

    Abdel Moneim, Ahmed E

    2016-06-01

    Treatment of rats with carbon tetrachloride (CCl4; 2 ml/kg body weight) once a week for 12 weeks caused a significant decrease in serum levels of testosterone, luteinizing hormone, and follicle-stimulating hormone. These decreases in sex hormones were reduced with Physalis peruviana L. (Cape gooseberry) juice supplementation. In addition, testicular activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase suppressed with CCl4 were elevated after P. peruviana juice supplements. P. peruviana juice supplementation significantly increased the testicular glutathione and significantly decreased the level of lipid peroxidation and the nitric oxide production compared with the CCl4 group. In addition, the decline in the activity of antioxidant enzymes after CCl4 was ameliorated by P. peruviana Moreover, degeneration of germ and Leydig cells along with deformities in spermatogenesis induced after CCl4 injections were prevented with the supplementation of P. peruviana juice. Furthermore, P. peruviana juice attenuated CCl4-induced apoptosis in testes tissue by inhibition of caspase-3 activity. The results clearly demonstrate that P. peruviana juice augments the antioxidants defense mechanism against CCl4-induced reproductive toxicity and provides evidence that the juice may have a therapeutic role in free radical-mediated diseases and infertility. PMID:25147302

  5. Hepatoprotective effects of sesamol loaded solid lipid nanoparticles in carbon tetrachloride induced sub-chronic hepatotoxicity in rats.

    PubMed

    Singh, Neha; Khullar, Neeraj; Kakkar, Vandita; Kaur, Indu Pal

    2016-05-01

    Sesamol is a phenolic component of sesame seed oil, which has been established as an antioxidant and also possesses potential for hepatoprotection. However, its protective role in carbon tetrachloride (CCl4 ) induced sub-chronic hepatotoxicity has not been studied. Limited oral bioavailability (BA) and rapid elimination (as conjugates) in rats is reported for sesamol. Considering its significant antioxidant potential and compromised BA, we packaged sesamol into solid lipid nanoparticles (S-SLNs) to enhance its hepatoprotective bioactivity. S-SLNs prepared by microemulsification method were nearly spherical in shape with an average particle size of 120.30 nm and their oral administration at 8 mg/kg body weight (BW) showed significantly (p < 0.001) better hepatoprotection than free sesamol (FS) and a well established hepatoprotective antioxidant silymarin [SILY (25 mg/kg BW); p < 0.05) in CCl4 induced sub-chronic liver injury in rats. Evaluations were done in terms of histological changes in the liver tissue, liver injury markers (serum alanine aminotransferase, serum aspartate aminotransferase, and serum lactate dehydrogenase); oxidative stress markers (lipid peroxidation, superoxide dismutase, and reduced glutathione) and proinflammatory response marker (tumor necrosis factor-alpha). © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 520-532, 2016. PMID:25410024

  6. 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

  7. 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

  8. 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

  9. 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

  10. Hepatoprotective effect of the natural fruit juice from Aronia melanocarpa on carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Valcheva-Kuzmanova, S; Borisova, P; Galunska, B; Krasnaliev, I; Belcheva, A

    2004-12-01

    The fruits of Aronia melanocarpa are rich in anthocyanins--plant pigments with anti-inflammatory and antioxidant activity. We studied the effect of the natural fruit juice from A. melanocarpa (NFJAM) on carbon tetrachloride (CCl4)-induced acute liver damage in rats. Histopathological changes such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins occurred in rats following acute exposure to CCl4 (0.2 ml kg(-1), 2 days). The administration of CCl4 increased plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, induced lipid peroxidation (as measured by malondialdehyde (MDA) content in rat liver and plasma) and caused a depletion of liver reduced glutathione (GSH). NFJAM (5, 10 and 20 ml kg(-1), 4 days) dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of plasma AST and ALT activities, induced by CCl4 (0.2ml kg(-1), 3rd and 4th days). NFJAM also prevented the CCl4-induced elevation of MDA formation and depletion of GSH content in rat liver. PMID:15625789

  11. 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.

  12. 3-Alkynyl selenophene protects against carbon-tetrachloride-induced and 2-nitropropane-induced hepatic damage in rats.

    PubMed

    Wilhelm, Ethel Antunes; Jesse, Cristiano Ricardo; Prigol, Marina; Alves, Diego; Schumacher, Ricardo Frederico; Nogueira, Cristina Wayne

    2010-12-01

    The aim of this study was to investigate the protective effect of 3-alkynyl selenophene (3-ASP) on acute liver injury induced by carbon tetrachloride (CCl(4)) and 2-nitropropane (2-NP) in rats. On the first day of treatment, the animals received 3-ASP (25 mg/kg, p.o.). On the second day, the rats received CCl(4) (1 mg/kg, i.p.) or 2-NP (100 mg/kg, p.o.). Twenty-four hours after CCl(4) or 2-NP administration, the animals were euthanized, and their plasma and liver were removed for biochemical and histological analyses. The histological analysis revealed extensive injury in the liver of CCl(4)-exposed and 2-NP-exposed rats, which was attenuated by 3-ASP. 3-ASP significantly attenuated (1) the increase in plasmatic aspartate and alanine aminotransferase activities and lipid peroxidation levels induced by CCl(4) and 2-NP; (2) the inhibition of δ-aminolevulinic dehydratase activity caused by 2-NP; and (3) the decrease in ascorbic acid (AA) levels and catalase (CAT) activity caused by CCl(4). AA levels and CAT activity remained unaltered in the liver of rats exposed to 2-NP. The protective effect of 3-ASP on acute liver injury induced by CCl(4) and 2-NP in rats was demonstrated. PMID:20397041

  13. 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}.

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

    PubMed Central

    Lin, Jung-Chun; Peng, Yi-Jen; Wang, Shih-Yu; 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. PMID:26798417

  15. 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

  16. 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

  17. Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver.

    PubMed

    Reza, Hasan Mahmud; Tabassum, Nabila; Sagor, Md Abu Taher; Chowdhury, Mohammed Riaz Hasan; Rahman, Mahbubur; Jain, Preeti; Alam, Md Ashraful

    2016-01-01

    Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats. PMID:26862777

  18. 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

  19. 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

  20. 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).

  1. 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

  2. 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. PMID:24825994

  3. Phytochemical analysis and hepatoprotective properties of Tinospora cordifolia against carbon tetrachloride-induced hepatic damage in rats

    PubMed Central

    Kavitha, B. T.; Shruthi, S. D.; Rai, S. Padmalatha; Ramachandra, Y. L.

    2011-01-01

    The present study was conducted to evaluate the hepatoprotective activity of different extracts of Tinospora cordifolia against carbon tetrachloride (CCl4) induced liver damage in rats. The pet ether, ethanol and aqueous extracts of various parts of the plant such as leaf, stem and root were tested at the dose of 200mg/kg body weight orally using Wistar albino rats and Silymarin was given as reference standard. Ethanolic extract of all the parts showed significant hepatoprotective effect by reduction in serum enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (TBL) in the selected model which is followed by aqueous and pet ether extracts. The chemical constituents reported from the plant belong to different classes such as alkaloids, flavanoids, glycosides, steroids, terpenoids, phenolics and saponins. The overall experimental results suggests that the biologically active phytoconstituents such as flavonoids, alkaloids present in the ethanolic extract of plant Tinospora cordifolia, may be responsible for the significant hepatoprotective activity. Therefore, results justify the use of Tinospora cordifolia as a hepatoprotective agent PMID:24826014

  4. 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.

  5. Ablation of aldehyde reductase aggravates carbon tetrachloride-induced acute hepatic injury involving oxidative stress and endoplasmic reticulum stress.

    PubMed

    Akihara, Ryusuke; Homma, Takujiro; Lee, Jaeyong; Yamada, Ken-Ichi; Miyata, Satoshi; Fujii, Junichi

    2016-09-16

    Aldehyde reductase (Akr1a) has been reported to be involved in the biosynthesis of ascorbic acid (AsA) in the mouse liver. Because Akr1a is expressed at high levels in the liver, we aimed to investigate the role of Akr1a in liver homeostasis by employing a carbon tetrachloride (CCl4)-induced hepatotoxicity model. Akr1a-deficient (Akr1a(-/-)) and wild-type (WT) mice were injected intraperitoneally with CCl4 and the extent of hepatic injury in the acute phase was assessed. Liver damage was heavier in the Akr1a(-/-) mice than in the WT mice. Furthermore, severe hepatic steatosis was observed in the livers of Akr1a(-/-) mice compared to WT mice and was restored to the levels in WT mice by AsA supplementation. Since the presence or absence of AsA had no effect on the decrease in CYP2E1 activity after the CCl4 treatment, it appears that AsA plays a role in the process after the bioactivation of CCl4. Biomarkers for oxidative stress and ER stress were markedly increased in the livers of Akr1a(-/-) mice and were effectively suppressed by AsA supplementation. Based on these collective results, we conclude that Akr1a exerts a protective effect against CCl4-induced hepatic steatosis by replenishing AsA via its antioxidative properties. PMID:27501753

  6. 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

  7. Methanolic extract of Woodfordia fruticosa Kurz flowers ameliorates carbon tetrachloride-induced chronic hepatic fibrosis in rats.

    PubMed

    Nitha, A; Prabha, S P; Ansil, P N; Latha, M S

    2016-07-01

    Hepatic fibrosis, characterized by extracellular matrix accumulation, is the common cause of chronic liver failure and is a leading cause of morbidity and mortality worldwide. The aim of the present study was to evaluate the effect of dried flowers of Woodfordia fruticosa on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rat model. Hepatic fibrosis was induced in male Wistar rats by CCl4 administration (150 μl/100 g rat weight, oral) twice a week for 10 weeks. In preventive model, administration of daily doses of methanolic extract of W. fruticosa (MEWF) at two different doses (100 mg/kg, body weight (b.w.) and 200 mg/kg, b.w.) was started 1 week before the onset of CCl4 administration and continued for 10 weeks. In curative model, MEWF at 100 and 200 mg/kg were given for last 2 weeks after the establishment of fibrosis. MEWF at a dose of 200 mg/kg was able to exert a more pronounced effect as evidenced histologically by significant reduction in fibrotic septa formation in liver tissue, immunohistochemically by abridged expression of collagen III, and also biochemically by serum and tissue antioxidant status, lipid peroxidation, and hydroxyproline level. Liquid chromatography-mass spectrometry analysis revealed the presence of confertin, quercetin methyl ether, ellagic acid, and stigmasterol in MEWF, which could be responsible for its antifibrotic activity. These results indicate the effective protection exerted by MEWF against CCl4-induced hepatic fibrosis in a dose-dependent manner. PMID:25415873

  8. 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.

  9. 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

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

    PubMed Central

    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

  11. Green tea extract therapy diminishes hepatic fibrosis mediated by dual exposure to carbon tetrachloride and ethanol: A histopathological study

    PubMed Central

    SAFER, ABDEL-MAJEED; AFZAL, MOHAMAD; HANAFY, NOMNY; MOUSA, SHAKER

    2015-01-01

    The aim of the present study was to investigate the hepatoprotective effect of green tea extract (GTE) against the hepatic fibrosis induced by carbon tetrachloride (CCl4), ethanol, and dual exposure to CCl4 plus ethanol in rats. In particular, an investigation of the three-dimensional architecture was conducted using scanning electron microscopy. Various techniques revealed that hepatic fibrosis with intermingled fibers was located between cells in the CCl4, ethanol and combined CCl4 plus ethanol groups. The hepatic fibrosis differed among the ethanol, CCl4 and CCl4 plus ethanol groups in terms of the type, thickness and distribution of fibers. The fibrotic lesions virtually disappeared in all the groups after 25 days of treatment with GTE, returning the architecture of the liver tissue to its normal status. The rats were also found to regain normal body weight and fur color, which had earlier been discolored due to weight loss. The autopsy results also showed that the animal livers returned to the normal shape and color. GTE demonstrated the same clear action in attenuating the hepatofibrosis for all three inducing treatments, by impairing collagen fibers, eliminating lipid peroxidation and returning the liver architecture to normal. GTE presents a safe therapeutic strategy for hepatic fibrosis. PMID:25667629

  12. 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. PMID:21508074

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Proper Heat Shock Pretreatment Reduces Acute Liver Injury Induced by Carbon Tetrachloride and Accelerates Liver Repair in Mice

    PubMed Central

    Li, San-Qiang; Wang, Dong-Mei; Shu, You-Ju; Wan, Xue-Dong; Xu, Zheng-Shun; Li, En-Zhong

    2013-01-01

    Whether proper heat shock preconditioning can reduce liver injury and accelerate liver repair after acute liver injury is worth study. So mice received heat shock preconditioning at 40°C for 10 minutes (min), 20 min or 30 min and recovered at room temperature for 8 hours (h) under normal feeding conditions. Then acute liver injury was induced in the heat shock-pretreated mice and unheated control mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl4). Hematoxylin and eosin (H&E) staining, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the expression levels of heat shock protein 70 (HSP70), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the unheated control mice and heat shock-pretreated mice after CCl4 administration. Our results showed that heat shock preconditioning at 40°C for 20 min remarkably improved the mice’s survival rate (P<0.05), lowered the levels of serum AST and ALT (P<0.05), induced HSP70 (P<0.01), CYP1A2 (P<0.01) and PCNA (P<0.05) expression, effectively reduced liver injury (P<0.05) and accelerated the liver repair (P<0.05) compared with heat shock preconditioning at 40°C for 10 min or 30 min in the mice after acute liver injury induced by CCl4 when compared with the control mice. Our results may be helpful in further investigation of heat shock pretreatment as a potential clinical approach to target liver injury PMID:24526809

  18. 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.

  19. 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

  20. Protection against carbon tetrachloride-induced hepatotoxicity by pretreating rats with the hemisuccinate esters of tocopherol and cholesterol.

    PubMed Central

    Fariss, M W; Bryson, K F; Hylton, E E; Lippman, H R; Stubin, C H; Zhao, X G

    1993-01-01

    Previous studies have demonstrated that alpha-tocopheryl hemisuccinate (TS) protects hepatocyte suspensions from chemical-induced toxicity. It has been suggested that TS cytoprotection is related to unique properties of the TS molecule or is dependent on the cellular release and activity of unesterified alpha-tocopherol (T). To test the unique cytoprotective nature of TS in vivo, the protective ability of T and tocopherol esters against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats was examined. Hepatoprotection [determined by serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and histopathology] was not observed after T (or tocopheryl acetate and tocopheryl nicotinate) administration, even though this treatment resulted in a fivefold elevation in hepatic T content. Only pretreatment with TS (100 mg/kg, intraperitoneally) resulted in partial hepatoprotection against CCl4 (2.9 g/kg, orally) toxicity. These findings suggest that hepatoprotection results not from the cellular accumulation of T but rather from the intact TS molecule. To test this hypothesis, the hepatoprotective capacity of cholesteryl hemisuccinate (CS), unesterified cholesterol, and cholesteryl acetate (CA) was examined against CCl4 toxicity. As observed with the tocopherol derivatives, pretreatment with unesterified cholesterol or CA demonstrated no protective ability. However, when rats were pretreated with CS (100 mg/kg), the hepatotoxic effects of CCl4 (elevated serum AST and ALT levels and centrilobular necrosis) were completely prevented. The prevention of CCl4-induced hepatotoxicity by CS and TS do not appear to result from an alteration in hepatic drug metabolism. These data clearly demonstrate that CS and TS are unique and powerful cytoprotective agents against CCl4 hepatotoxicity in vivo.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1. a Figure 1. b Figure 1. c Figure 1. d Figure 2. a Figure 2. b Figure 2. c PMID:8137782

  1. 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

  2. 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

  3. Modulation of carbon tetrachloride-induced hepatic oxidative stress, injury and fibrosis by olmesartan and omega-3.

    PubMed

    Shaaban, Ahmed A; Shaker, Mohamed E; Zalata, Khaled R; El-kashef, Hassan A; Ibrahim, Tarek M

    2014-01-25

    This study was designed to investigate the potential effects of omega-3, olmesartan and their combination on established hepatic fibrosis in the carbon tetrachloride (CCl4) rat model. Male Wistar rats received subcutaneous injections of CCl4 twice weekly for 12weeks, as well as daily oral treatments of olmesartan (1 and 3mg/kg), omega-3 (75 and 150mg/kg) and their combination during the last 4weeks of intoxication. Our results indicated that omega-3 and, to a lesser extent, olmesartan dose-dependently blunted CCl4-induced necroinflammation scoring and elevation of liver injury parameters in serum. Besides, omega-3 and, to a lesser extent, olmesartan treatments in a dose dependent manner attenuated CCl4-induced liver fibrosis, as demonstrated by hepatic histopathology scoring and 4-hydroxyproline content. The mechanisms behind these beneficial effects of both omega-3 and olmesartan were also elucidated. These include (1) counteracting hepatic oxidative stress and augmenting hepatic antioxidants; (2) preventing the activation of hepatic stellate cells (HSCs), as denoted by reducing α-smooth muscle actin (α-SMA) expression in the liver; (3) inhibiting the proliferation and chemotaxis of HSCs, as evidenced by downregulating platelet-derived growth factor receptors-β (PDGFR-β) expression in the liver; and (4) inhibiting the fibrogenesis response of HSCs, as indicated by inhibiting the secretion of transforming growth factor-β1 (TGF-β1). Unexpectedly, when olmesartan was co-administered with omega-3, it interfered with the hepatoprotective and anti-fibrotic activities of omega-3. In conclusion, this study introduces the first evidence regarding the pronounced anti-fibrotic activity of omega-3 and suggests that it may be beneficial in the treatment of hepatic fibrosis in humans. PMID:24144775

  4. 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

  5. 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

  6. 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

  7. Role of fibroblast growth factor type 1 and 2 in carbon tetrachloride-induced hepatic injury and fibrogenesis.

    PubMed

    Yu, Chundong; Wang, Fen; Jin, Chengliu; Huang, Xinqiang; Miller, David L; Basilico, Claudio; McKeehan, Wallace L

    2003-10-01

    Genomic ablation of hepatocyte-specific fibroblast growth factor receptor (FGFR)4 in mice revealed a role of FGF signaling in cholesterol and bile acid metabolism and hepatolobular restoration in response to injury without effect on liver development or hepatocyte proliferation. Although the potential role of all 23 FGF polypeptides in the liver is still unclear, the most widely studied prototypes, FGF1 and FGF2, are present and have been implicated in liver cell growth and function in vitro. To determine whether FGF1 and FGF2 play a role in response to injury and fibrosis, we examined the impact of both acute and chronic exposure to carbon tetrachloride (CCl(4)) in the livers of FGF1- and FGF2-deficient mice. After acute CCl(4) exposure, FGF1(-/-)FGF2(-/-) mice exhibited an accelerated release of serum alanine aminotransferase similar to FGFR4 deficiency, but no effect on overall hepatolobular restoration or bile acid metabolism. FGF1(-/-)FGF2(-/-) mice exhibited a normal increase in alpha-smooth muscle actin and desmin associated with activation and migration of hepatic stellate cells to damage, but a reduced level of hepatic stellate cell-derived matrix collagen alpha1(I) synthesis. Liver fibrosis resulting from chronic CCl(4) exposure was markedly decreased in the livers of FGF1/FGF2-deficient mice. These results suggest an agonist role for FGF1 and FGF2 in specifically insult-induced liver matrix deposition and hepatic fibrogenesis and a potential target for the prevention of hepatic fibrosis. PMID:14507672

  8. Protective effects of alisol B 23-acetate from edible botanical Rhizoma alismatis against carbon tetrachloride-induced hepatotoxicity in mice.

    PubMed

    Meng, Qiang; Chen, Xinli; Wang, Changyuan; Liu, Qi; Sun, Huijun; Sun, Pengyuan; Huo, Xiaokui; Liu, Zhihao; Liu, Kexin

    2015-04-01

    Carbon tetrachloride (CCl4)-induced hepatotoxicity is a common syndrome with simultaneous severe hepatocyte death and acute cholestasis. The purpose of the present study is to investigate the hepatoprotective effect of alisol B 23-acetate (AB23A), a natural triterpenoid from edible botanical Rhizoma alismatis, on acute hepatotoxicity induced by CCl4 in mice, and further to elucidate the involvement of farnesoid X receptor (FXR), signal transducers and activators of transcription 3 (STAT3) in the hepatoprotective effect. H&E staining, BrdU immunohistochemistry and TUNEL assay were used to identify the amelioration of histopathological changes, hepatocyte proliferation and apoptosis. Real-time PCR and western blot assay were used to elucidate the mechanisms underlying AB23A hepatoprotection. The results indicated that AB23A treatment in a dose-dependent manner resulted in protection against hepatotoxicity induced by CCl4via FXR activation. Through FXR activation, AB23A promoted hepatocyte proliferation via an induction in hepatic levels of FoxM1b, Cyclin D1 and Cyclin B1. AB23A also reduced hepatic bile acids through a decrease in hepatic uptake transporter Ntcp, bile acid synthetic enzymes Cyp7a1, Cyp8b1, and an increase in efflux transporter Bsep, Mrp2 expression. In addition, AB23A induced the expression of STAT3 phosphorylation, and STAT3 target genes Bcl-xl and SOCS3, resulting in decreased hepatocyte apoptosis. In conclusion, AB23A produces a protective effect against CCl4-induced hepatotoxicity, due to FXR and STAT3-mediated gene regulation. PMID:25747392

  9. 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). PMID:26929368

  10. Neutralization of ADAM8 ameliorates liver injury and accelerates liver repair in carbon tetrachloride-induced acute liver injury.

    PubMed

    Li, San-Qiang; Zhu, Sha; Wan, Xue-Dong; Xu, Zheng-Shun; Ma, Zhao

    2014-04-01

    Although some studies have described the function of ADAM8 (a disintegrin and metalloprotease 8) related with rheumatoid arthritis, cancer and asthma, etc., the concrete role of ADAM8 in acute liver injury is still unknown. So mice respectively received anti-ADAM8 monoclonal antibody (mAb) of 100 μg/100 μl, 200 μg/100 μl or 300 μg/100 μl in PBS or PBS pre-injection. Then acute liver injury was induced in the mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄). Serum AST and ALT level, Haematoxylin-eosin (H&E) staining, the expression level of vascular endothelial growth factor (VEGF), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the mice after CCl4 administration. Our results showed that anti-ADAM8 mAb pre-injection could effectively lower AST and ALT levels (P < 0.05 or P < 0.01) and reduce liver injury (P < 0.05 or P <0.01), induce the expression of VEGF, CYP1A2 and PCNA (P <0.05 or P < 0.01) in dose-dependent manner compared with the control mice which received PBS pre-injection. In summary, our study suggested that ADAM8 might promote liver injury by inhibiting the proliferation of hepatocytes, angiogenesis and affecting the metabolism function of liver during acute liver injury induced by CCl₄. Anti-ADAM8 mAb injection might be suitable as a potential method for acute liver injury therapy. PMID:24646716

  11. Effect of flavonoid compounds extracted from Iris species in prevention of carbon tetrachloride-induced liver fibrosis in rats.

    PubMed

    Wang, Y L; Lv, H Y; Zhang, Q

    2015-01-01

    We investigated the effect of flavonoid compounds extracted from species of genus Iris L. on carbon tetrachloride (CCl4)-induced rat liver fibrosis. Thirty Sprague-Dawley rats were randomly divided into normal control group, liver fibrosis model group, and drug treatment group (N = 10 each). Next, 0.2 mL/100 g CCl4 was subcutaneously injected for 6 weeks in both model and treatment rats to generate the liver fibrosis model. In the control group, an equal volume of castor oil was injected subcutaneously. Rats in the treatment group also received 100 mg·kg(-1)·day(-1) flavonoid compounds via gastric tubes. After 6 weeks, rats were sacrificed, and their liver tissues were examined for pathological changes, including alanine aminotransferase, aspartate aminotransferase, total bilirubin, hyaluronic acid, laminin, and procollagen type-3. Liver tissues from control rats showed no significant pathological changes, while model animals showed significant liver fibrosis. In the treatment group, liver fibrosis significantly decreased compared to the model group (P < 0.05). Liver fibrotic indices, including hyaluronic acid, laminin, and procollagen type-3, in treatment rats were all significantly lower than those in the model group (P < 0.05), but not significantly different compared to the normal group (P > 0.05). Other liver function indices, including alanine aminotransferase, aspartate aminotransferase, and total bilirubin, in treatment rats were also significantly lower than those in model rats (P < 0.01) but higher than those in control animals (P < 0.05). Flavonoid compounds extracted from Iris plants showed significant inhibitory effects on CCl4-induced rat liver fibrosis. PMID:26400326

  12. Transport of Carbon Tetrachloride in a Fractured Vadose Zone due to Atmospheric Pressure Fluctuations, Diffusion, and Vapor Density

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Downs, W.; Falta, R. W.; Housley, T.

    2005-12-01

    DNAPL sources of carbon tetrachloride (CT) vapors are of interest at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The site is underlain by thick fractured basalt that includes sedimentary interbeds, each are a few meters thick. Daily atmospheric pressure fluctuations serve as driving forces for CT vapor transport in the subsurface. Other important transport processes for vapor movement include gas-phase diffusion and density-driven transport. The objective of this research is to investigate the influence and relative importance of these processes on gaseous transport of CT. Gas pressure and vapor concentration measurements were conducted at various depths in two wells. A numerical multiphase flow model (TOUGH2), calibrated to field pressure data, is used to conduct sensitivity analyses to elucidate the importance of the different transport mechanisms. Results show that the basalt is highly permeable to vertical air flow. The pressure dampening occurs mainly in the sedimentary interbeds. Model-calibrated permeability values for the interbeds are similar to those obtained in a study by the U.S. Geological Survey for shallow sediments, and an order of magnitude higher than column-scale values obtained by previous studies conducted by INEEL scientists. The transport simulations indicate that considering the effect of barometric pressure changes is critical to simulating transport of pollutants in the vadose zone above the DNAPL source. Predicted concentrations can be orders of magnitude smaller than actual concentrations if the effect is not considered. Below the DNAPL vapor source, accounting for density and diffusion alone would yield acceptable results provided that a 20% error in concentrations are acceptable, and that simulating concentrations trends (and not actual concentrations) is the primary goal.

  13. In vivo gene transfer of endothelial nitric oxide synthase decreases portal pressure in anaesthetised carbon tetrachloride cirrhotic rats

    PubMed Central

    Van de Casteele, M; Omasta, A; Janssens, S; Roskams, T; Desmet, V; Nevens, F; Fevery, J

    2002-01-01

    Background: Portal hypertension in cirrhosis results from enhanced intrahepatic resistance to an augmented inflow. The former is partly due to an imbalance between intrahepatic vasoconstriction and vasodilatation. Enhanced endothelin-1 and decreased activity of hepatic constitutive endothelial nitric oxide synthase (NOS 3) was reported in carbon tetrachloride (CCl4) cirrhotic rat liver. Aims: To study whether an increase in hepatic NOS 3 could be obtained in the CCl4 cirrhotic rat liver by in vivo cDNA transfer and to investigate a possible effect on portal pressure. Methods: Hepatic NOS 3 immunohistochemistry and western blotting were used to measure the amount of NOS 3 protein. Recombinant adenovirus, carrying cDNA encoding human NOS 3, was injected into the portal vein of CCl4 cirrhotic rats. Cirrhotic controls received carrier buffer, naked adenovirus, or adenovirus carrying the lac Z gene. Results: NOS 3 immunoreactivity and amount of protein (western blotting) were significantly decreased in CCl4 cirrhotic livers. Following cDNA transfer, NOS 3 expression and the amount of protein were partially restored. Portal pressure was 11.4 (1.6) mm Hg in untreated cirrhotic (n=9) and 11.8 (0.6) in lac Z transfected (n=4) cirrhotic rats but was reduced to 7.8 (1.0) mm Hg (n=9) five days after NOS 3 cDNA transfer. No changes were observed in systemic haemodynamics, in liver tests or urinary nitrates, or in NOS 3 expression in lung or kidney, indicating a highly selective transfer. Conclusions: NOS 3 cDNA transfer to cirrhotic rat liver is feasible and the increase in hepatic NOS 3 leads to a marked decrease in portal hypertension without systemic effects. These data indicate a major haemodynamic role of intrahepatic NOS 3 in the pathogenesis of portal hypertension in CCl4 cirrhosis. PMID:12171971

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Carbon tetrachloride induced kidney and lung tissue damages and antioxidant activities of the aqueous rhizome extract of Podophyllum hexandrum

    PubMed Central

    2011-01-01

    Background The present study was conducted to evaluate the in vitro and in vivo antioxidant properties of aqueous extract of Podophyllum hexandrum. The antioxidant potential of the plant extract under in vitro situations was evaluated by using two separate methods, inhibition of superoxide radical and hydrogen peroxide radical. Carbon tetrachloride (CCl4) is a well known toxicant and exposure to this chemical is known to induce oxidative stress and causes tissue damage by the formation of free radicals. Methods 36 albino rats were divided into six groups of 6 animals each, all animals were allowed food and water ad libitum. Group I (control) was given olive oil, while the rest groups were injected intraperitoneally with a single dose of CCl4 (1 ml/kg) as a 50% (v/v) solution in olive oil. Group II received CCl4 only. Group III animals received vitamin E at a concentration of 50 mg/kg body weight and animals of groups IV, V and VI were given extract of Podophyllum hexandrum at concentration dose of 20, 30 and 50 mg/kg body weight. Antioxidant status in both kidney and lung tissues were estimated by determining the activities of antioxidative enzymes, glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and superoxide dismutase (SOD); as well as by determining the levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS). In addition, superoxide and hydrogen peroxide radical scavenging activity of the extract was also determined. Results Results showed that the extract possessed strong superoxide and hydrogen peroxide radical scavenging activity comparable to that of known antioxidant butylated hydroxy toluene (BHT). Our results also showed that CCl4 caused a marked increase in TBARS levels whereas GSH, SOD, GR, GPX and GST levels were decreased in kidney and lung tissue homogenates of CCl4 treated rats. Aqueous extract of Podophyllum hexandrum successfully prevented the alterations of these effects

  19. 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

  20. 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

  1. 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

  2. Reductive metabolism of carbon tetrachloride by human cytochromes P-450 reconstituted in phospholipid vesicles: mass spectral identification of trichloromethyl radical bound to dioleoyl phosphatidylcholine.

    PubMed Central

    Trudell, J R; Bösterling, B; Trevor, A J

    1982-01-01

    It has been proposed that covalent binding of reactive metabolites to liver membrane constituents may be responsible for the hepatoxicity of carbon tetrachloride. This study demonstrates that trichloromethyl free radical is the major reductive metabolite of carbon tetrachloride by cytochrome P-450 and that this free radical is capable of binding to double bonds of fatty acyl chains of the phospholipids in the membrane surrounding cytochrome P-450. The structural identification of the reactive free radical metabolite and the product of its addition to phospholipids was accomplished by use of a reconstituted system of human cytochromes P-450, NADPH-cytochrome P-450 reductase, and cytochrome b5 in phospholipid vesicles. The reconstituted vesicles contained a mixture of dioleoyl phosphatidylcholine and egg phosphatidylethanolamine that served as both structural components and targets for trichloromethyl free radical binding. After incubation of these vesicles under a N2 atmosphere in the presence of NADPH with 14CCl4, the phospholipids were extracted and then separated by high-pressure liquid chromatography. The dioleoyl phosphatidylcholine fraction was transesterified and the resulting single 14C-labeled fatty acid methyl ester was purified by reverse-phase chromatography. Desorption chemical ionization mass spectrometry with ammonia as reagent gas as well as desorption electron-impact mass spectrometry permitted identification of the molecular structure as a mixture of 9- and 10-(trichloromethyl)stearate methyl esters. PMID:6953422

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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

  9. Protective effect of compounds from the flowers of Citrus aurantium L. var. amara Engl against carbon tetrachloride-induced hepatocyte injury.

    PubMed

    Lu, Qun; Yang, Li; Zhao, Hai-Yan; Jiang, Jian-Guo; Xu, Xi-Lin

    2013-12-01

    5-Hydroxy-6,7,3',4'-tetramethoxyflavone (HTF), limonexic acid (LA) are two compounds isolated from the flowers of Citrus aurantium L. var. amara Engl with various biological activities. This study was designed to investigate their protective effects against carbon tetrachloride (CCl4)-induced hepatocyte injury, using human hepatic cell line HL-7702 to determine the cell cytotoxicity, cell viability, levels of hepatic marker enzymes, malondialdehyde (MDA). Results showed that pretreatment with HTF, LA could significantly reverse CCl4-induced HL-7702 cell viability decrease, LA displayed a higher activity. HTF, LA also showed their capability of decreasing the CCl4-induced leakage of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), inhibiting the lipid peroxidation, HTF showed more significant activity. Given that HTF, LA were not toxic, it is concluded that HTF, LA could effectively protect hepatocyte against CCl4-induced injury. PMID:23985451

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Antioxidant, hepatoprotective, and ameliorative effects of methanolic extract of leaves of Grewia mollis Juss. on carbon tetrachloride-treated albino rats.

    PubMed

    Asuku, Oiza; Atawodi, Sunday E; Onyike, Elewechi

    2012-01-01

    The methanolic extract of Grewia mollis leaves was evaluated in vivo for its antioxidant and hepatoprotective properties. Oxidative stress was induced in rats by administering carbon tetrachloride (CCl(4)) intraperitoneally at a dose of 0.6 mL/kg, whereas the crude plant extract and standard antioxidant (vitamin E) were administered at a dose of 5 mg/kg and 50 mg/kg, respectively. The effect of G. mollis crude extracts and vitamin E on malondialdehyde (MDA) and liver function parameters such as protein, bilirubin, aspartate aminotransferase, and alanine aminotransferase were measured spectrophotometrically. The methanolic extract of G. mollis leaves and vitamin E showed a significant (P<.05) hepatoprotective potential by lowering the serum levels of bilirubin, aspartate aminotransferase, and alanine aminotransferase and decreasing MDA levels in rats pretreated or post-treated with CCl(4). Based on these results, it is concluded that G. mollis leaves contain potent antioxidant compounds that could offer protection against hepatotoxicity as well as ameliorate preexisting liver damage and oxidative stress conditions. PMID:21877945

  18. 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

  19. 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

  20. Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats

    PubMed Central

    Wohlenberg, Mariane; Almeida, Daniela; Bokowski, Liane; Medeiros, Niara; Agostini, Fabiana; Funchal, Cláudia; Dani, Caroline

    2014-01-01

    In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl4). The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS) were unchanged. However, CCl4 induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD) activity was increased by CCl4 in the cerebral cortex and decreased in other tissues. However, CCl4 increased catalase (CAT) activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract. PMID:26784867

  1. Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats.

    PubMed

    Wohlenberg, Mariane; Almeida, Daniela; Bokowski, Liane; Medeiros, Niara; Agostini, Fabiana; Funchal, Cláudia; Dani, Caroline

    2014-01-01

    In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl₄). The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS) were unchanged. However, CCl₄ induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD) activity was increased by CCl₄ in the cerebral cortex and decreased in other tissues. However, CCl₄ increased catalase (CAT) activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract. PMID:26784867

  2. 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

  3. 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

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

    PubMed Central

    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

  5. 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 . PMID:23410011

  6. 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

  7. Protective Effects of Extract from Sclerotium of the King Tuber Medicinal Mushroom, Pleurotus tuberregium (Higher Basidiomycetes) on Carbon Tetrachloride-Induced Hepatotoxicity in Wistar Albino Rats.

    PubMed

    Alagbaoso, Chidube A; Osubor, Christopher C; Isikhuemhen, Omoanghe S

    2015-01-01

    This study was undertaken to investigate the effect of 50% ethanol extract from the sclerotia of Pleurotus tuberregium on hepatocellular integrity of albino rats treated with carbon tetrachloride (CCl4). Activities of hepatic enzymes alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) were determined in serum. Antioxidant enzyme activities, total protein, and level of malondialdehyde (MDA) were assayed in liver homogenate from treated rats. Oral administration of CCl4 (2 ml/kg body weight/day) for 7 consecutive days caused hepatotoxicity. There was a significant increase in the activity of serum ALT, AST, and ALP and the level of MDA in the liver. However, the activities of catalase and superoxide dismutase, which are antioxidant enzymes, were significantly reduced (p < 0.05). Concomitant treatment with 250 mg/kg body weight of extract and CCl4 for 7 consecutive days resulted in a significant decrease in the activity of liver marker enzymes [46% (ALT), 67.25% (AST), and 68.51% (ALP)]. These activities were further decreased [68.24% (ALT), 78.39% (AST), and 75.38% (ALP)] when the extract was increased to 500 mg/kg body weight. The activities of antioxidant enzymes, total protein, and MDA content of the liver were improved to levels that are not significantly different from the control. These findings, therefore, suggest that ethanol extract from the sclerotia of P. tuberregium has a protective action against CCl4-induced hepatotoxicity. PMID:26854100

  8. 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

  9. 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

  10. Hepatoprotective and anti-hepatitis C viral activity of Platycodon grandiflorum extract on carbon tetrachloride-induced acute hepatic injury in mice.

    PubMed

    Kim, Tae-Won; Lim, Jong-Hwan; Song, In-Bae; Park, Sang-Jin; Yang, Jae-Won; Shin, Jung Cheul; Suh, Joo-Won; Son, Hwa-Young; Cho, Eun-Sang; Kim, Myoung-Seok; Lee, Sang-Wook; Kim, Jong-Woo; Yun, Hyo-In

    2012-01-01

    The present study aims to evaluate the anti-HCV activity of hotwater extract from Platycodon grandiflorum (BC703) with HCV genotype 1b subgenomic replicon system and investigate its hepatoprotective activity on carbon tetrachloride (CCl(4))-induced acute liver damage in mice. BC703 produced significant hepatoprotective effects against CCl(4)-induced acute hepatic injury by decreasing the activities of serum enzymes, nitric oxide and lipid peroxidation. Histopathological studies further substantiated the protective effect of BC703. Furthermore, BC703 inhibited the HCV RNA replication with an EC(50) value and selective index (CC(50)/EC(50)) of 2.82 µg/mL and above 35.46, respectively. However, digested BC703 using a simulated gastric juice showed poor protective effect against CCl(4)-induced hepatotoxicity in mice and decreased anti-HCV activity as compared to the intact BC703. Although further studies are necessary, BC703 may be a beneficial agent for the management of acute hepatic injury and chronic HCV infection. PMID:22878389

  11. 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.

  12. 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

  13. 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)

  14. Method of purifying zirconium tetrachloride and hafnium tetrachloride in a vapor stream

    SciTech Connect

    Snyder, T.S.; Stolz, R.A.

    1992-04-07

    This patent describes a method of purifying zirconium tetrachloride and hafnium tetrachloride in a vapor stream from a sand chlorinator in which the silicon and metals present in sand fed to the chlorinator are converted to chlorides at temperatures over about 800{degrees} C. It comprises cooling a vapor stream from a sand chlorinator, the vapor stream containing principally silicon tetrachloride, zirconium tetrachloride, and hafnium tetrachloride contaminated with ferric chloride, to a temperature of from about 335{degrees} C to about 600{degrees} C; flowing the vapor stream through a gaseous diffusion separative barrier to produce a silicon tetrachloride-containing vapor stream concentrated in zirconium tetrachloride and hafnium tetrachloride and a silicon tetrachloride-containing vapor stream depleted in zirconium tetrachloride and hafnium tetrachloride; adsorbing the ferric chloride in the separative barrier; and recovering the silicon tetrachloride stream concentrated in zirconium tetrachloride and hafnium tetrachloride separately from the silicon tetrachloride stream depleted in zirconium tetrachloride and hafnium tetrachloride.

  15. 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

  16. 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 ...

  17. 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

  18. 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.

  19. Protective effect of selected calcium channel blockers and prednisolone, a phospholipase-A2 inhibitor, against gentamicin and carbon tetrachloride-induced nephrotoxicity.

    PubMed

    Akindele, A J; Adeneye, A A; Olatoye, F; Benebo, A S

    2014-08-01

    The ameliorative effect of calcium channel blockers (CCBs) and a phospholipase-A2 inhibitor in drug-/chemical-induced nephrotoxicity was investigated. Rats were divided into 7 groups of 5 rats in each group. In the gentamicin model, group I rats were pretreated with normal saline (10 ml kg(-1)), while groups II-VII rats were pretreated with normal saline (10 ml kg(-1)), ascorbic acid (10 mg kg(-1)), nifedipine (0.86 mg kg(-1)), verapamil (4.3 mg kg(-1)), diltiazem (3.43 mg kg(-1)), and prednisolone (0.57 mg kg(-1)), respectively, perorally 1 h before intraperitoneal (i.p.) injection of gentamicin (40 mg kg(-1)) for 14 days. In the carbon tetrachloride (CCl4) model, rats were pretreated with CCBs and prednisolone for 7 days before inducing nephrotoxicity with 20% CCl4 (1.5 ml kg(-1)). Rats were thereafter killed and blood and tissue samples were collected for assessments. I.p. injections of gentamicin and CCl4 caused significant hypernatremia, hypokalemia, hypocalcemia, hypophosphatemia, and hyperchloremic alkalosis and reduced renal tissue levels of antioxidants. Also, significant reductions in the hemoglobin, packed cell volume, red blood cells, and platelet indices were observed. Pretreatments with nifedipine (0.86 mg kg(-1)), verapamil (4.3 mg kg(-1)), diltiazem (3.43 mg kg(-1)), and prednisolone (0.57 mg kg(-1)) significantly ameliorated the deleterious effects of gentamicin and CCl4 possibly via antioxidant and anti-lipoperoxidation mechanisms. The results obtained in this study suggest potential clinical usefulness of tested CCBs and prednisolone in drug-/chemical-induced nephrotoxicity. PMID:24220874

  20. P2X7 receptor-NADPH oxidase axis mediates protein radical formation and Kupffer cell activation in carbon tetrachloride-mediated steatohepatitis in obese mice.

    PubMed

    Chatterjee, Saurabh; Rana, Ritu; Corbett, Jean; Kadiiska, Maria B; Goldstein, Joyce; Mason, Ronald P

    2012-05-01

    While some studies show that carbon tetrachloride-mediated metabolic oxidative stress exacerbates steatohepatitic-like lesions in obese mice, the redox mechanisms that trigger the innate immune system and accentuate the inflammatory cascade remain unclear. Here we have explored the role of the purinergic receptor P2X7-NADPH oxidase axis as a primary event in recognizing the heightened release of extracellular ATP from CCl(4)-treated hepatocytes and generating redox-mediated Kupffer cell activation in obese mice. We found that an underlying condition of obesity led to the formation of protein radicals and posttranslational nitration, primarily in Kupffer cells, at 24h post-CCl(4) administration. The free radical-mediated oxidation of cellular macromolecules, which was NADPH oxidase and P2X7 receptor-dependent, correlated well with the release of TNF-α and MCP-2 from Kupffer cells. The Kupffer cells in CCl(4)-treated mice exhibited increased expression of MHC Class II proteins and showed an activated phenotype. Increased expression of MHC Class II was inhibited by the NADPH oxidase inhibitor apocynin , P2X7 receptor antagonist A438709 hydrochloride, and genetic deletions of the NADPH oxidase p47 phox subunit or the P2X7 receptor. The P2X7 receptor acted upstream of NADPH oxidase activation by up-regulating the expression of the p47 phox subunit and p47 phox binding to the membrane subunit, gp91 phox. We conclude that the P2X7 receptor is a primary mediator of oxidative stress-induced exacerbation of inflammatory liver injury in obese mice via NADPH oxidase-dependent mechanisms. PMID:22343416

  1. Determination of the key innate genes related to individual variation in carbon tetrachloride-induced hepatotoxicity using a pre-biopsy procedure

    SciTech Connect

    Yun, Jun-Won; Kim, Chae-Wook; Bae, Il-Hong; Park, Young-Ho; Chung, Jin-Ho; Lim, Kyung-Min Kang, Kyung-Sun

    2009-08-15

    High inter-individual variation in chemical-induced liver injury is a frequent observation with many hepatotoxic chemicals, yet the mechanism underlying it remains poorly understood. Even with carbon tetrachloride (CCl{sub 4}), a well-known model hepatotoxicant, substantial individual variations are observed in the severity of liver injury. Using microarray, many attempts have been made to identify the key genes in CCl{sub 4}-induced liver injury but mostly, they examined the gene expression of liver after CCl{sub 4} exposure, unable to dissect out the complicating factors from pathological changes secondary to liver injury. To more accurately identify the genes for the individual variation in CCl{sub 4}-induced hepatotoxicity, we compared the innate gene expression of the individual liver samples pre-biopsied prior to CCl{sub 4}-treatment with the severity of liver injury after CCl{sub 4}-treatment. Effect of biopsy procedure and 3 week recovery period on liver function and gene expression were confirmed to be insignificant. Using this design, we found that the expression of genes associated with immunity and defense, lipid metabolism, transport and complement-mediated immunity, which are previously known to be suppressed by CCl{sub 4}-treatment, were innately lower in the susceptible animals than resistant animals. Moreover, we demonstrated that the genes such as Gsta2, Sult2a1, Fgl1 and C6 were newly found to be innately lower in the susceptible animals to CCl{sub 4}-hepatotoxicity. These naturally lower gene expression patterns were further confirmed by RT-PCR. We believe that this pre-biopsy design may provide a useful tool for understanding the cause of variability of hepatotoxicity and for the prediction and pre-screening of the susceptible individual to drug-induced hepatotoxicity.

  2. Non-covalent C-Cl…π interaction in acetylene-carbon tetrachloride adducts: Matrix isolation infrared and ab initio computational studies.

    PubMed

    Ramanathan, N; Sundararajan, K; Vidya, K; Jemmis, Eluvathingal D

    2016-03-15

    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. PMID:26722673

  3. 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.

  4. 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

  5. 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

  6. Carbon Tetrachloride Increases the Pro-inflammatory Cytokines Levels in Different Brain Areas of Wistar Rats: The Protective Effect of Acai Frozen Pulp.

    PubMed

    de Souza Machado, Fernanda; Marinho, Jéssica Pereira; Abujamra, Ana Lúcia; Dani, Caroline; Quincozes-Santos, André; Funchal, Cláudia

    2015-09-01

    Acai offers health benefits associated with its high antioxidante capacity, phytochemical composition, nutritional and sensory value. Therefore, the objective of this study was to evaluate the protective effect of acai frozen pulp on carbon tetrachloride (CCl4)-induced damage via modulation of anti- and pro-inflammatory cytokines in rat brain tissue. The rats were treated via oral (gavage) daily with water or acai frozen pulp for 14 days at a dose of 7 μL/g. On the 15th day, the animals in each group received a single intraperitoneal injection of CCl4 in a dose of 3.0 mL/kg or the same volume of mineral oil. After 4 h, the animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were dissected and homogenated to evaluate the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 18 (IL-18), interleukin 6 (IL-6) and interleukin 10 (IL-10). Data were statistically analyzed by analysis of variance followed by the Tukey post hoc test. It was observed that CCl4 increased TNF-α, IL-1β and IL-18 levels in all brain tissues, and that acai frozen pulp was able to prevent this increase. IL-6 and IL-10 brain tissue levels remained unchanged during all treatments. CCl4 experimental model was suitable to investigate brain tissue anti and pro-inflammatory cytokines. Acai frozen pulp prevented an increase in IL-1β, IL-18 and TNF-α, while IL-6 and IL-10 levels remained unchanged. The precise pathway by which inflammation contribute to hepatic encephalopathy, as well as to how this pathway can be modulated, is still under investigation. PMID:26283513

  7. 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

  8. 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

  9. 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. PMID:20812277

  10. 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

  11. 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

  12. Hepatic Progenitor Cells Contribute to the Progression of 2-Acetylaminofluorene/Carbon Tetrachloride-Induced Cirrhosis via the Non-Canonical Wnt Pathway.

    PubMed

    Chen, Jiamei; Zhang, Xiao; Xu, Ying; Li, Xuewei; Ren, Shuang; Zhou, Yaning; Duan, Yuyou; Zern, Mark; Zhang, Hua; Chen, Gaofeng; Liu, Chenghai; Mu, Yongping; Liu, Ping

    2015-01-01

    Hepatic progenitor cells (HPCs) appear to play an important role in chronic liver injury. In this study, cirrhosis was induced in F-344 rats (n = 32) via subcutaneous injection of 50% carbon tetrachloride (CCl4) twice a week for 8 weeks. Then, 30% CCl4 was administered in conjunction with intragastric 2-acetylaminofluorine (2-AAF) for 4 weeks to induce activation of HPCs. WB-F344 cells were used to provide direct evidence for differentiation of HPCs to myofibroblasts. The results showed that after administration of 2-AAF, the hydroxyproline content and the expressions of α-SMA, Col I, Col IV, TGF-β1, CD68, TNF-α, CK19 and OV6 were significantly increased. OV6 and α-SMA were largely co-expressed in fibrous septum and the expressions of Wnt5b, frizzled2, frizzled3 and frizzled6 were markedly increased, while β-catenin expression was not statistically different among the different groups. Consistent with the above results, WB-F344 cells, treated with TGF-β1 in vitro, differentiated into myofibroblasts and α-SMA, Col I, Col IV, Wnt5b and frizzled2 expressions were significantly increased, while β-catenin expression was decreased. After blocking the non-canonical Wnt pathway via WIF-1, the Wnt5b level was down regulated, and α-SMA and F-actin expressions were significantly decreased in the WIF-1-treated cells. In conclusion, these results indicate that HPCs appear to differentiate into myofibroblasts and exhibit a profibrotic effect in progressive cirrhosis via activation of the non-canonical Wnt pathway. Blocking the non-canonical Wnt pathway can inhibit the differentiation of HPCs into myofibroblasts, suggesting that blocking this pathway and changing the fate of differentiated HPCs may be a potential treatment for cirrhosis. PMID:26087010

  13. Antioxidant and Hepatoprotective Activities of Ethanolic Extracts of Leaves of Premna esculenta Roxb. against Carbon Tetrachloride-Induced Liver Damage in Rats

    PubMed Central

    Mahmud, ZA; Bachar, SC; Qais, N

    2012-01-01

    Premna esculenta Roxb. (family Verbenaceae) is a shrub used by the ethnic people of Chittagong Hill Tracts of Bangladesh for the treatment of hepatocellular jaundice. The present study was done to evaluate the hepatoprotective and the in vivo antioxidant activity of ethanolic extracts of leaves of the plant in carbon tetrachloride-induced liver damage in rats. Hepatotoxicity was induced in rats by i.p. injection of CCl4 diluted with olive oil (1:1 v/v; 1 mL/kg body weight) on alternate days for 7 days. After 7 days of pretreatment of test extracts, the biochemical markers such as Serum Glutamate Oxaloacetate Transaminase (SGOT), Serum Glutamate Pyruvate Transaminase (SGPT), Alkaline Phosphatase (ALP), total protein, and albumin were estimated followed by the measurement of liver cytosolic antioxidant enzymes such as superoxide dismutase, catalase, and peroxidase. The data were analyzed using one-way analysis of variance (ANOVA) followed by Dunnett's t-test. The extract both at the doses of 200 and 400 mg/kg p.o. significantly (P < 0.001) reduced the elevated levels of SGPT, SGOT, ALP and increased the reduced levels of total protein and albumin compared to the CCl4-treated animals. The extracts also showed a significant (P < 0.001) increase in the reduced levels of superoxide dismutase (SOD), catalase, and peroxidase. The effects of the extracts on these parameters were comparable with those of the standard, silymarin. The findings of the study indicate that the leaf extract of P. esculenta showed a potential hepatoprotective activity and the protective action might have manifested by restoring the hepatic SOD, catalase, and peroxidase levels. The results justify the traditional use of this plant in liver disorders. PMID:23493235

  14. 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...

  15. Spin trapping of free radical metabolites of carbon tetrachloride in vitro and in vivo: Effect of acute ethanol administration

    SciTech Connect

    Reinke, L.A.; Towner, R.A.; Janzen, E.G. )

    1992-01-01

    A single dose of ethanol, when administered 18 hr prior to CCl4, potentiates the hepatotoxicity of the halocarbon. In these studies, spin trapping and electron spin resonance (ESR) spectroscopy methods were utilized to determine whether a single ethanol dose increased the metabolism of CCl4 to free radical intermediates. When hepatic microsomes from ethanol-treated or control rats were incubated with CCl4 and the spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN), the ESR signal of the trichloromethyl radical adduct of PBN was of similar intensity in both groups. The ethanol dose also failed to induce p-nitrophenol hydroxylase activity. When PBN and CCl4 were administered to rats, liver extracts contained ESR signals resulting primarily from the trichloromethyl radical adduct of PBN, and the signals were of similar intensity in both experimental groups. Higher concentrations of the carbon dioxide anion radical adduct of PBN were detected in plasma samples from ethanol-treated rats. However, when hepatocytes from ethanol-treated and control rats were incubated with PBN and CCl4, ESR signals of the carbon dioxide adduct were of similar intensity. These data suggest that the higher concentrations of the carbon dioxide adduct in the blood of ethanol-treated rats may be explained by early CCl4-induced damage to liver cell membranes, rather than increased rates of formation. The data in this report fail to support the hypothesis that a single dose of ethanol stimulates the hepatic metabolism of CCl4 to the trichloromethyl radical. Alternatively, ethanol may potentiate CCl4 toxicity by affecting some critical metabolic step subsequent to trichloromethyl radical formation.

  16. Destruction of organohalides in water using metal particles: Carbon tetrachloride/water reactions with magnesium, tin and zinc

    SciTech Connect

    Boronina, T.; Klabunde, K.J.

    1996-01-12

    As a possible method for degrading chlorocarbons in contaminated water supplies, the reactions of metallic magnesium, tin, and zinc with CCl4/H2O mixtures have been studied. In the case of Mg, oxidation by water overwhelmed the Mg-CCl4 reaction. However, Sn and Zn were successfully used to degrade CCl4. Sn and Zn behave quite differently with the final carbon-containing product, with Zn being CH4 but with Sn being CO2. This is rationalized by the competing reactions of a possible intermediate Cl3CMCl, which can be protonated by H2O to give CHCl2 or eliminate CCl2 (which subsequently reacts with water to form CO2 and HCl). Metal surface areas are also important, and the most active metal samples were prepared by a metal vapor-solvent codeposition method (SMAD cryo-particles). However, conventional Zn dust and Sn granules were also effective, only with lower reaction rates.

  17. 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

  18. 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

  19. Carbon tetrachloride-induced liver disease in rats: the potential effect of supplement oils with vitamins E and C on the nutritional status

    PubMed Central

    Ismail, Rasha S. A.; El-Megeid, Ashraf A. A.; Abdel-Moemin, Aly R.

    2009-01-01

    The aim of the present investigation was to study the effects of olive oil (OO), corn oil (CO), and flaxseed oil (FO), with or without supplementation of vitamins E and C, on food intake, body weight gain %, liver weight to body weight %, total lipids, liver functions, and liver histology in male rats intoxicated with carbon tetrachloride (CCl4). Forty-two rats were divided into two main groups. The first main group was fed on basal diet (BD) as a negative control group (NC). The second main group received subcutaneous injections of CCl4 in paraffin oil (50% v/v 2ml/kg) twice a week to induce chronic damage in the liver. The group was then divided into six subgroups, three of which were fed on 4% unsupplemented oils (CO, FO, and OO) as positive control for the three oils used. The rest of the groups were fed on 4% of the same oils supplemented with vitamins E and C. The results of the flaxseed oil rat group indicate that supplementing vitamin E and C led to a significant reduction in the mean values of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and liver alanine amino transferase enzyme (ALT). Moreover, it caused an increase of the mean value of high-density lipoprotein cholesterol (HDL-C) as compared to the negative control group (NC). The olive oil group supplemented with the same vitamins showed a significant decrease in the mean value of serum TC and significant (P<0.05) increase in the mean value of serum HDL-C as compared to NC. The results of the corn oil group supplemented with vitamins showed a significant increase in the mean value of serum HDL-C as compared to the negative control group. The histology results confirmed that the group hepatically injured with CCl4 treatment and fed on supplemented FO or OO showed apparently normal hepatocytes. Conclusion: The most effective treatment was observed with oils supplemented with vitamins E and C. Hierarchically FO achieved the best results compared to other additives, followed by OO

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Activated carbons and low cost adsorbents for remediation of tri- and hexavalent chromium from water.

    PubMed

    Mohan, Dinesh; Pittman, Charles U

    2006-09-21

    Hexavalent chromium is a well-known highly toxic metal, considered a priority pollutant. Industrial sources of Cr(VI) include leather tanning, cooling tower blowdown, plating, electroplating, anodizing baths, rinse waters, etc. The most common method applied for chromate control is reduction of Cr(VI) to its trivalent form in acid (pH approximately 2.0) and subsequent hydroxide precipitation of Cr(III) by increasing the pH to approximately 9.0-10.0 using lime. Existing overviews of chromium removal only cover selected technologies that have traditionally been used in chromium removal. Far less attention has been paid to adsorption. Herein, we provide the first review article that provides readers an overview of the sorption capacities of commercial developed carbons and other low cost sorbents for chromium remediation. After an overview of chromium contamination is provided, more than 300 papers on chromium remediation using adsorption are discussed to provide recent information about the most widely used adsorbents applied for chromium remediation. Efforts to establish the adsorption mechanisms of Cr(III) and Cr(VI) on various adsorbents are reviewed. Chromium's impact environmental quality, sources of chromium pollution and toxicological/health effects is also briefly introduced. Interpretations of the surface interactions are offered. Particular attention is paid to comparing the sorption efficiency and capacities of commercially available activated carbons to other low cost alternatives, including an extensive table. PMID:16904258

  6. Carbon-Based Sorbents with Three-Dimensional Architectures for Water Remediation.

    PubMed

    Chen, Bo; Ma, Qinglang; Tan, Chaoliang; Lim, Teik-Thye; Huang, Ling; Zhang, Hua

    2015-07-15

    Over the past decade, carbon-based 3D architectures have received increasing attention in science and technology due to their fascinating properties, such as a large surface area, macroscopic bulky shape, and interconnected porous structures, enabling them to be one of the most promising materials for water remediation. This review summarizes the recent development in design, preparation, and applications of carbon-based 3D architectures derived from carbon nanotubes, graphene, biomass, or synthetic polymers for water treatment. After a brief introduction of these materials and their synthetic strategies, their applications in water treatment, such as the removal of oils/organics, ions, and dyes, are summarized. Finally, future perspective directions for this promising field are also discussed. PMID:25808922

  7. 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

  8. Excretion of formaldehyde, malondialdehyde, acetaldehyde and acetone in the urine of rats in response to 2,3,7,8-tetrachlorodibenzo-p-dioxin, paraquat, endrin and carbon tetrachloride.

    PubMed

    Shara, M A; Dickson, P H; Bagchi, D; Stohs, S J

    1992-05-01

    Formaldehyde (FA), acetaldehyde (ACT), malondialdehyde (MDA) and acetone (ACON) were simultaneously identified in urine, and their excretion quantitated in response to chemically induced oxidative stress. Urine samples of female Sprague-Dawley rats were collected over dry ice and derivatized with 2,4-dinitrophenylhydrazine. The hydrazones of the four lipid metabolic products were quantitated by high-performance liquid chromatography on a Waters 10-microns mu-Bondapak C18 column. The identities of FA, ACT, MDA and ACON in urine were confirmed by gas chromatography-mass spectrometry. An oxidative stress was induced by orally administering 100 micrograms/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin, 75 mg/kg paraquat, 6 mg/kg endrin or 2.5 ml/kg carbon tetrachloride to rats. Urinary excretion of FA, ACT, MDA and ACON increased relative to control animals 24 h after treatment with all xenobiotics. The system has wide-spread applicability to the investigation of altered lipid metabolism in disease states and exposure to environmental pollutants. PMID:1400710

  9. 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

    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

  10. 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.

  11. Evaluation of the sediment remediation potential of magnetite impregnated activated carbons and biochars

    NASA Astrophysics Data System (ADS)

    Werner, David; Han, Zhantao; Karapanagioti, Hrissi

    2014-05-01

    We evaluated the sediment remediation potential of magnetic composite materials synthesized by precipitating magnetite minerals onto activated carbons and biochars. Magnetite impregnation did not reduce the phenanthrene sorption capacity of the activated carbon or biochar component of the composite materials. The phenanthrene sorption capacity of the composite materials correlated with the surface areas of the pristine carbonaceous sorbents. XRD data and mass magnetic susceptibility data indicate that the mineral component of the composites is indeed nearly 100% magnetite. Addition of magnetic activated carbon to River Tyne sediment slurries reduced polycyclic aromatic hydrocarbon availability by more than 90%. After 3 months of mixing, 77% of the added magnetic activated carbon could be recovered with a magnetic rod. Continued monitoring showed that polycyclic aromatic hydrocarbon availability remained low following the magnetic recovery of most of the added sorbent mass. XRD analysis confirmed the presence of magnetite in the recovered sorbent material, with some other mineral phases such as calcite and quartz also being identifiable. Magnetic activated carbon has potential as a recoverable sorbent amendment for the treatment of sediment polluted with hydrophobic organic compounds. Further work will include an evaluation of the long-term magnetic sorbent effectiveness and stability in unmixed sediments under aerobic and anaerobic conditions and regeneration and re-use options for the recovered sorbent materials.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

    PubMed

    Liu, Xitao; Yu, Gang

    2006-04-01

    The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil. PMID:16213557

  17. 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

  18. 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

  19. l-Theanine prevents carbon tetrachloride-induced liver fibrosis via inhibition of nuclear factor κB and down-regulation of transforming growth factor β and connective tissue growth factor.

    PubMed

    Pérez-Vargas, J E; Zarco, N; Vergara, P; Shibayama, M; Segovia, J; Tsutsumi, V; Muriel, P

    2016-02-01

    Here we evaluated the ability of L-theanine in preventing experimental hepatic cirrhosis and investigated the roles of nuclear factor-κB (NF-κB) activation as well as transforming growth factor β (TGF-β) and connective tissue growth factor (CTGF) regulation. Experimental hepatic cirrhosis was established by the administration of carbon tetrachloride (CCl4) to rats (0.4 g/kg, intraperitoneally, three times per week, for 8 weeks), and at the same time, adding L-theanine (8.0 mg/kg) to the drinking water. Rats had ad libitum access to water and food throughout the treatment period. CCl4 treatment promoted NF-κB activation and increased the expression of both TGF-β and CTGF. CCl4 increased the serum activities of alanine aminotransferase and γ-glutamyl transpeptidase and the degree of lipid peroxidation, and it also induced a decrease in the glutathione and glutathione disulfide ratio. L-Theanine prevented increased expression of NF-κB and down-regulated the pro-inflammatory (interleukin (IL)-1β and IL-6) and profibrotic (TGF-β and CTGF) cytokines. Furthermore, the levels of messenger RNA encoding these proteins decreased in agreement with the expression levels. L-Theanine promoted the expression of the anti-inflammatory cytokine IL-10 and the fibrolytic enzyme metalloproteinase-13. Liver hydroxyproline contents and histopathological analysis demonstrated the anti-fibrotic effect of l-theanine. In conclusion, L-theanine prevents CCl4-induced experimental hepatic cirrhosis in rats by blocking the main pro-inflammatory and pro-fibrogenic signals. PMID:25852135

  20. 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.

  1. 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

  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. 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. PMID:23876256

  4. 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.

  5. 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.

  6. 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...

  7. 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. PMID:25550081

  8. 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

  9. 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.

  10. The effect of ionic strength and hardness of trichloroethylene contaminated groundwater in remediation using granular activated carbon

    NASA Astrophysics Data System (ADS)

    Heo, J.; Chang, H.

    2005-12-01

    The objective of this study is to evaluate the trichloroethylene (TCE) removal by granular activated carbon (GAC) based on influential factors (ionic strength, hardness) of various groundwaters. The experimental method used in this study was batch experiments. Synthetic groundwater for test was made according to ionic strength, hardness and then it was artificially contaminated by TCE 5ppm. The variation of ions in synthetic groundwater was measured by I.C. and I.C.P. Surface area of GAC was determined by the Brunauer, Emmett and Teller (BET) adsorption data. The results of tests showed that TCE removal using GAC is affected by the hardness of synthetic groundwaters. It was founded that surface area of GAC was decreased by increasing of ions. Due to pore blocking of ions by functional group, the surface area of GAC decreased and the difference of the remediation appeared. This result was affected by the ionic strength and hardness of water. Therefore, the ionic strength and hardness of contaminated groundwater must be considered in remediation using GAC.

  11. 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

  12. 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.

  13. 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

  14. 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. PMID:26992666

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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. PMID:26874318

  3. Literature information applicable to the reaction of uranium oxides with chlorine to prepare uranium tetrachloride

    SciTech Connect

    Haas, P.A.

    1992-02-01

    The reaction of uranium oxides and chlorine to prepare anhydrous uranium tetrachloride (UCl{sub 4}) are important to more economical preparation of uranium metal. The most practical reactions require carbon or carbon monoxide (CO) to give CO or carbon dioxide (CO{sub 2}) as waste gases. The chemistry of U-O-Cl compounds is very complex with valances of 3, 4, 5, and 6 and with stable oxychlorides. Literature was reviewed to collect thermochemical data, phase equilibrium information, and results of experimental studies. Calculations using thermodynamic data can identify the probable reactions, but the results are uncertain. All the U-O-Cl compounds have large free energies of formation and the calculations give uncertain small differences of large numbers. The phase diagram for UCl{sub 4}-UO{sub 2} shows a reaction to form uranium oxychloride (UOCl{sub 2}) that has a good solubility in molten UCl{sub 4}. This appears more favorable to good rates of reaction than reaction of solids and gases. There is limited information on U-O-Cl salt properties. Information on the preparation of titanium, zirconium, silicon, and thorium tetrachlorides (TiCl{sub 4}, ZrCl{sub 4}, SiCl{sub 4}, ThCl{sub 4}) by reaction of oxides with chlorine (Cl{sub 2}) and carbon has application to the preparation of UCl{sub 4}.

  4. Reduction of nitro aromatic compounds in Fe(0)-CO{sub 2}-H{sub 2}O systems: Implications for groundwater remediation with iron metal

    SciTech Connect

    Agrawal, A.

    1995-07-01

    The properties of iron metal that make it useful in remediation of chlorinated solvents may also lead to reduction of other groundwater contaminants such as nitro aromatic compounds (NACs). This possibility has been investigated in batch experiments using aqueous carbonate media to determine the kinetics and mechanism of nitro reduction by iron metal, and to learn more about the effect of precipitation on the reactivity of the metal surfaces under geochemical conditions. Nitrobenzene is reduced by iron under anaerobic conditions to aniline with nitrosobenzene as an intermediate product. Detectable amounts of coupling products such as azobenzene and azoxybenzene were not found. First-order reduction rates are similar for nitrobenzene and nitrosobenzene, but aniline appearance occurs more slowly. The nitro reduction rate increased linearly with concentration of iron surface area, giving a specific reaction rate constant which is roughly 16-fold greater than has been reported for dehalogenation of carbon tetrachloride.

  5. 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

  6. 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.

  7. 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). PMID:22828309

  8. REMOVAL OF TECHNETIUM, CARBON TETRACHLORIDE, AND METALS FROM DOE PROPERTIES

    EPA Science Inventory

    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 ag...

  9. Low-energy electron scattering by carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Moreira, Giseli M.; Souza Barbosa, Alessandra; Pastega, Diego F.; Bettega, Márcio H. F.

    2016-02-01

    In this work we report calculated integral and differential elastic cross sections for the scattering of low-energy electrons by CCl4. We employ the Schwinger multichannel method with pseudopotentials to compute the cross sections in the static-exchange and static-exchange plus polarization approximations for energies up to 15 eV. We report two shape resonances located at 0.75 eV and 8 eV belonging to the T 2 and E symmetries of the T d group respectively. We also look at the s-wave contribution to the integral cross section and find no evidence of the presence of a Ramsauer-Townsend minimum. We compare our calculated cross sections with available experimental and theoretical results and find that in general the agreement is good.

  10. 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...

  11. Substrate effect on the enhanced biodegradation of carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Wu, Shian C.; Doong, Rueyan

    1993-03-01

    The effects of different substrates on the biotransformation of heavily chlorinated hydrocarbons under anaerobic conditions were investigated to evaluate the feasibility of in-situ bioremediation of the contaminated groundwaters by amending different substrates. The substrate-fed batches were anaerobically incubated with the addition of either acetate, glucose, methanol, or dissolved organic matter (DOM) with concentrations ranging from 10 to 30 mg/L. Experimental results demonstrated that the effect of the substrates on the dechlorination of the compounds varied. The removal efficiency was observed greatest for glucose- then methanol- and acetate-fed batches and least for DOM-fed batches. The sequence of the enhancement efficiency is consistent with the sequence of the reducing potentials of these substrates. Changing the substrate concentration could vary the dechlorination capability of the system. The viable counts of microorganisms determined by the direct epifluorescence counting technique showed that the batches with higher concentration of the supplemental substrate produced higher bacterial cell numbers. Moreover, from microscopic observations, different compositions of bacterial population were found. Small-sized bacteria with spheric shape were observed when culture bottles were amended with either acetate or DOM, whereas large-sized bacteria with rod-shape were predominant for bottles amended with glucose. Also, higher DNA contents were demonstrated for glucose-fed batches.

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

    SciTech Connect

    Mallouk, Thomas E.; Darab, John G.

    1999-06-01

    The objective of this research is to prepare, characterize, and evaluate new materials for the removal of technetium (Tc) compounds, halogenated organics, and other troublesome metals from DOE waste streams and contaminated areas. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (Cr, Hg, Pb, Cd) and Re (as a surrogate for Tc) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for supported iron that will optimize selectivity for the contaminants of interest. The support composition is of particular interest in the case of Tc separation and stabilization in the Hanford tank wastes. While tests with tank waste simulants have shown that pertechnetate is reduced insoluble TcO2, the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes.

  13. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties.

    SciTech Connect

    Mallouk, Thomas E.; Ponder, Sherman M.; Darab, John

    2000-06-01

    The objective of this research is to prepare, characterize, and evaluate new materials for the removal of technetium (Tc) compounds, halogenated organics, and other troublesome metals from DOE waste streams and contaminated areas. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (Cr, Hg, Pb, Cd) and Re (as a surrogate for Tc) to insoluble forms faster and with higher efficiency than does unsupported iron. Liquid-liquid extraction methods are also being developed for quantitative removal of Cs from tetraphenylborate salt mixtures, which are generated in waste processing at Savannah River, and conversion to vitrifiable inorganic Cs salts.

  14. Carbon tetrachloride-induced liver injury in the rabbit.

    PubMed Central

    Bernacchi, A. S.; de Castro, C. R.; de Ferreyra, E. C.; Villarruel, M. C.; Fernández, G.; de Fenos, O. M.; Castro, J. A.

    1983-01-01

    CCl4 administration to rabbits leads to early destruction of liver microsomal cytochrome P-450, to depression of glucose 6 phosphatase, to ultrastructurally revealable alterations and to an intense necrosis and fat accumulation in liver. Despite the known resistance of rabbit liver microsomes to lipid peroxidation, CCl4 administration to rabbits promoted lipid peroxidation of their liver microsomal lipids as revealable by the diene hyperconjugation technique, at periods of time from 1 to 12 h. Nevertheless, the intensity of this process is not equivalent to that occurring in rat liver microsomes, since the arachidonic acid content of rabbit liver microsomal lipids does not decrease at either 6 or 24 h after CCl4 administration. Rabbit liver is able to activate CCl4 to reactive metabolites that bind covalently to lipids. Relevance of covalent binding of CCl4 reactive metabolites and CCl4-promoted lipid peroxidation to CCl4-induced rabbit liver injury is analysed. Images Fig. 1 Fig. 2 PMID:6309207

  15. 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

  16. 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

  17. Development of a Novel Titania Slag Upgrading Process Using Titanium Tetrachloride

    NASA Astrophysics Data System (ADS)

    Kang, Jungshin; Okabe, Toru H.

    2016-02-01

    In order to remove iron from titania slag for the production of high-grade titanium dioxide (TiO2), a novel slag upgrading process was developed based on a selective chlorination method. In the experiments, various types of suitably pretreated slag reacted with titanium tetrachloride (TiCl4) as a chlorinating agent at 1100 K (827 °C) for 5 hours in the presence of carbon. Once the reaction had reached completion, the iron in the slags was selectively removed as iron chloride (FeCl2) in a dry form. As a result, the mass percent of iron decreased from 13.9 to 0.21 pct (nominal, excluding oxygen) and the mass percent of titanium increased from 78.1 to 96.0 pct (nominal, excluding oxygen) under certain conditions. Therefore, this selective chlorination process using TiCl4 is considered a feasible approach for the upgrading of titania slag.

  18. Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent

    SciTech Connect

    McLaughlin, D.F.; Stoltz, R.A.

    1988-04-12

    In an extractive distillation method for separating hafniuim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which extractive distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a molten salt solvent is circulated into the reflux condenser and through the column to provide a liquid phase, and wherein molten salt solvent containing zirconium tetrachloride is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux condenser and hafnium tetrachloride enriched vapor is taken as product from the reflux condenser, the improvement is described comprising: the molten salt having a composition of at least 30 mole percent zinc chloride and at least 10 mole percent of lead chloride.

  19. Effectiveness of an anaerobic granular activated carbon fluidized-bed bioreactor to treat soil wash fluids: a proposed strategy for remediating PCP/PAH contaminated soils.

    PubMed

    Koran, K M; Suidan, M T; Khodadoust, A P; Sorial, G A; Brenner, R C

    2001-07-01

    An integrated system has been developed to remediate soils contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil-solvent washing and anaerobic biotreatment of the extract. Specifically, this study evaluated the effectiveness of a granular activated carbon (GAC) fluidized-bed reactor to treat a synthetic-waste stream of PCP and four PAHs (naphthalene, acenaphthene, pyrene, and benzo(b)fluoranthene) under anaerobic conditions. This waste stream was intended to simulate the wash fluids from a soil washing process treating soils from a wood-preserving site. The reactor achieved a removal efficiency of greater than 99.8% for PCP with conversion to its dechlorination intermediates averaging 46.5%. Effluent, carbon extraction, and isotherm data also indicate that naphthalene and acenaphthene were removed from the liquid phase with efficiencies of 86 and 93%, respectively. Effluent levels of pyrene and benzo(b)fluoranthene were extremely low due to the high-adsorptive capacity of GAC for these compounds. Experimental evidence does not suggest that the latter two compounds were biochemically transformed within the reactor. PMID:11394769

  20. 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…

  1. 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.

  2. 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. PMID:24168448

  3. 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.

  4. 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

  5. Health effects of silicon tetrachloride. Report of an urban accident

    SciTech Connect

    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. 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

  7. 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

  8. 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

  9. 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...

  10. Dissociative electron attachment to titatinum tetrachloride and titanium tetraisopropoxide

    NASA Astrophysics Data System (ADS)

    Bjarnason, Elías H.; Ómarsson, Benedikt; Engmann, Sarah; Ómarsson, Frímann H.; Ingólfsson, Oddur

    2014-05-01

    Here we present a dissociative electron attachment study of titanium tetrachloride and titanium tetraisopropoxide in the incident electron energy range from about 0-18 eV. The results are compared to electron impact ionization and fragmentation of these compounds and discussed in relation to the role of secondary electrons in focused electron beam induced deposition. We also use the opportunity and describe in detail a recently constructed crossed beam apparatus for the study of the energy dependency of ion formation in low energy electron interaction with gas phase molecules. Contribution to the Topical Issue "Electron and Positron Induced Processes", edited by Michael Brunger, Radu Campeanu, Masamitsu Hoshino, Oddur Ingólfsson, Paulo Limão-Vieira, Nigel Mason, Yasuyuki Nagashima and Hajime Tanuma.

  11. 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.

  12. 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.

  13. 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.

  14. 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…

  15. 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.

  16. Modifying metal nanoparticle placement on carbon supports using an aerosol-based process, with application to the environmental remediation of chlorinated hydrocarbons.

    PubMed

    Sunkara, Bhanukiran; Zhan, Jingjing; Kolesnichenko, Igor; Wang, Yingqing; He, Jibao; Holland, Jennifer E; McPherson, Gary L; John, Vijay T

    2011-06-21

    A facile aerosol-based process (ABP) is developed to vary the placement of iron nanoparticles on the external surface of carbon microspheres or within the interior. This is accomplished through the competitive mechanisms of sucrose carbonization and the precipitation of soluble iron salts, in an aerosol droplet passing through a high temperature heating zone. At lower aerosolization temperatures, carbonization occurs first leading to iron salt precipitation on the external surface, while at higher temperatures interior placement occurs through concurrent iron salt precipitation and sucrose carbonization. The resulting composites are highly conducive to the reductive dechlorination of compounds such as trichloroethylene (TCE) as the carbon support is a strong adsorbent, and zerovalent iron effectively reduces TCE to innocuous gases such as ethane. Since both iron and carbon are widely used catalysts and catalyst supports, the simple process of modifying iron placement has significant potential applications in heterogeneous catalysis. PMID:21612244

  17. Risk-based prioritization for the interim remediation of inactive low-level liquid radioactive waste underground storage tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Chidambariah, V.; Travis, C.C.; Trabalka, J.R.; Thomas, J.K.

    1992-09-01

    The paper presents a risk-based approach for rapid prioritization of low-level liquid radioactive waste underground storage tanks (LLLW USTs), for possible interim corrective measures and/or ultimate closure. The ranking of LLLW USTs is needed to ensure that tanks with the greatest potential for adverse impact on the environment and human health receive top priority for further evaluation and remediation. Wastes from the LLLW USTs at Oak Ridge National Laboratory were pumped out when the tanks were removed from service. The residual liquids and sludge contain a mixture of radionuclides and chemicals. Contaminants of concern that were identified in the liquid phase of the inactive LLLW USTs include the radionuclides {sup 90}Sr, {sup 137}Cs, and {sup 233}U and the chemicals carbon tetrachloride, trichloroethane, tetrachloroethene, methyl ethyl ketone, mercury, lead, and chromium. The risk-based approach for prioritization of the LLLW USTs is based upon three major criteria: (1) leaking characteristics of the tank, (2) location of the tanks, and (3) toxic potential of the tank contents. Leaking characteristics of LLLW USTs will aid in establishing the potential for the release of contaminants to environmental media. In this study, only the liquid phase was assumed to be released to the environment. Scoring criteria for release potential of LLLW USTs was determined after consideration of the magnitude of any known leaks and the tank type for those that are not known to leak.

  18. Risk-based prioritization for the interim remediation of inactive low-level liquid radioactive waste underground storage tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Chidambariah, V.; Travis, C.C.; Trabalka, J.R.; Thomas, J.K.

    1992-09-01

    The paper presents a risk-based approach for rapid prioritization of low-level liquid radioactive waste underground storage tanks (LLLW USTs), for possible interim corrective measures and/or ultimate closure. The ranking of LLLW USTs is needed to ensure that tanks with the greatest potential for adverse impact on the environment and human health receive top priority for further evaluation and remediation. Wastes from the LLLW USTs at Oak Ridge National Laboratory were pumped out when the tanks were removed from service. The residual liquids and sludge contain a mixture of radionuclides and chemicals. Contaminants of concern that were identified in the liquid phase of the inactive LLLW USTs include the radionuclides [sup 90]Sr, [sup 137]Cs, and [sup 233]U and the chemicals carbon tetrachloride, trichloroethane, tetrachloroethene, methyl ethyl ketone, mercury, lead, and chromium. The risk-based approach for prioritization of the LLLW USTs is based upon three major criteria: (1) leaking characteristics of the tank, (2) location of the tanks, and (3) toxic potential of the tank contents. Leaking characteristics of LLLW USTs will aid in establishing the potential for the release of contaminants to environmental media. In this study, only the liquid phase was assumed to be released to the environment. Scoring criteria for release potential of LLLW USTs was determined after consideration of the magnitude of any known leaks and the tank type for those that are not known to leak.

  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. 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

  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. SEDIMENT ASSESSMENT AND REMEDIATION PROGRAM

    EPA Science Inventory

    Assessment and Remediation of Contaminated Sediments (ARCS) is an integrated program for the development and testing of assessment and remedial action alternatives for contaminated sediments. Information from ARCS program activities will be used to guide the development of Remedi...

  4. 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)

  5. 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.

  6. Cognitive remediation in schizophrenia.

    PubMed

    Medalia, Alice; Choi, Jimmy

    2009-09-01

    Cognitive deficits are routinely evident in schizophrenia, and are of sufficient magnitude to influence functional outcomes in work, social functioning and illness management. Cognitive remediation is an evidenced-based non-pharmacological treatment for the neurocognitive deficits seen in schizophrenia. Narrowly defined, cognitive remediation is a set of cognitive drills or compensatory interventions designed to enhance cognitive functioning, but from the vantage of the psychiatric rehabilitation field, cognitive remediation is a therapy which engages the patient in learning activities that enhance the neurocognitive skills relevant to their chosen recovery goals. Cognitive remediation programs vary in the extent to which they reflect these narrow or broader perspectives but six meta-analytic studies report moderate range effect sizes on cognitive test performance, and daily functioning. Reciprocal interactions between baseline ability level, the type of instructional techniques used, and motivation provide some explanatory power for the heterogeneity in patient response to cognitive remediation. PMID:19444614

  7. 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

  8. 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

  9. Effects of intermittent contaminant loading on the bed capacity of activated carbon filters

    SciTech Connect

    Hemenway, D.R.; Fitzgerald, B.J.; Paret, T.

    1982-09-01

    The effects of intermittent contaminant loading compared to constant contaminant loading on the bed capacity of an activated carbon filter under constant flow conditions were investigated. Two separate studies were conducted, one with benzene as the contaminant, the other utilizing carbon tetrachloride as the contaminant. A 16% reduction in effective bed capacity was observed for benzene and a 20% reduction occurred with carbon tetrachloride under equal loading and flushing intervals. It was found that a significant reduction in bed capacity under periodic loading - constant air flow conditions occurred when compared with constant loading - constant flow situations.

  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. Stabilization of positive charge on polytetrafluoroethylene electret films treated with titanium-tetrachloride vapor

    NASA Astrophysics Data System (ADS)

    Rychkov, Dmitry; Gerhard, Reimund

    2011-03-01

    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 °C

  12. Remediating Common Math Errors.

    ERIC Educational Resources Information Center

    Wagner, Rudolph F.

    1981-01-01

    Explanations and remediation suggestions for five types of mathematics errors due either to perceptual or cognitive difficulties are given. Error types include directionality problems, mirror writing, visually misperceived signs, diagnosed directionality problems, and mixed process errors. (CL)

  13. Remedial Parathyroid Surgery

    PubMed Central

    Udelsman, Robert; Donovan, Patricia Irvin

    2006-01-01

    Objective: To review the outcomes in 130 consecutive remedial explorations for primary hyperparathyroidism. Summary Background Data: Remedial surgery for primary hyperparathyroidism is challenging and requires meticulous preoperative evaluation and imaging to expedite a focused surgical exploration that has traditionally been performed under general anesthesia. This prospective series of 130 consecutive remedial operations for primary hyperparathyroidism selectively used minimally invasive techniques and tested the hypothesis that these techniques could improve outcomes. Methods: Between 1990 and 2005, 1090 patients were evaluated and explored for primary hyperparathyroidism. Of these, 130 remedial explorations were performed in 128 patients who underwent either conventional exploration under general anesthesia (n = 107) or minimally invasive parathyroidectomy (n = 23) employing cervical block anesthesia, directed exploration, and curative confirmation with the rapid intraoperative parathyroid hormone assay. Results: The sensitivity of preoperative imaging were: Sestamibi (79%), ultrasound (74%), MRI (47%), CT (50%), venous localization (93%), and ultrasound guided parathyroid fine needle aspiration (78%). The cure rate in the conventional remedial group (n = 107) was 94% and was associated with a mean length of stay of 1.6 ± 0.2 days. Remedial exploration employing minimally invasive techniques (n = 23) resulted in a cure rate of 96% and a mean length of stay of 0.4 ± 0.1 days. Complications were rare in both remedial groups. These results were almost identical to those achieved in 960 unexplored patients. Conclusions: Remedial parathyroid surgery can be accomplished with acceptable cure and complication rates. Minimally invasive techniques can achieve outcomes that are similar to those obtained in unexplored patients. PMID:16926573

  14. 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.

  15. 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.

  16. 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.

  17. HEPATOTOXIC INTERACTIONS OF ETHANOL WITH ALLYL ALCOHOL OR CARBON TETRACHLORIDE IN RATS

    EPA Science Inventory

    To assess interactive toxicity following subacute, concurrent chemical exposure, male Fischer-344 rats, approximately 70 days of age, were given ethanol at 0, 0.'05, 0.1, 0.2, or 0.5 ml/kg in corn oil daily by gavage for 14 days ([TON group), or the same levels of ethanol with 21...

  18. Protective effects of Pycnogenol on carbon tetrachloride-induced hepatotoxicity in Sprague-Dawley rats.

    PubMed

    Yang, Young-Su; Ahn, Tai-Hwan; Lee, Jong-Chan; Moon, Chang-Jong; Kim, Sung-Ho; Jun, Woojin; Park, Seung-Chun; Kim, Hyoung-Chin; Kim, Jong-Choon

    2008-01-01

    Oxidative damage is implicated in the pathogenesis of various liver injuries. In the present study the ability of Pycnogenol (PYC) as an antioxidant to protect against CCl4-induced oxidative stress and hepatotoxicity in rats was investigated. Four experimental groups of six rats each were constructed: a vehicle control group received the respective vehicles (distilled water and corn oil) only; a CCl4 group received a 14-day repeated intraperitoneal (i.p.) dose of distilled water and then a single oral dose of CCl4 at 1.25 ml/kg; and the CCl4&PYC 10 and CCl4&PYC 20 groups received a 14-day repeated i.p. dose of PYC 10 and 20 mg/kg, respectively, and then a single oral dose of CCl4 at 1.25 ml/kg. Hepatotoxicity was assessed 24 h after the CCl4 treatment by measurement of serum aminotransferase (AST) and alanine aminotransferase (ALT) activities, hepatic malondialdehyde (MDA) and glutathione (GSH) concentrations, and catalase, superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities. The results were confirmed histopathologically. The single oral dose of CCl4 produced significantly elevated levels of serum AST and ALT activities. Histopathological examinations showed extensive liver injuries, characterized by extensive hepatocellular degeneration/necrosis, fatty changes, inflammatory cell infiltration, congestion, and sinusoidal dilatation. In addition, an increased MDA concentration and decreased GSH, catalase, SOD, and GST were observed in the hepatic tissues. On the contrary, PYC treatment prior to the administration of CCl4 significantly prevented the CCl4-induced hepatotoxicity, including the elevation of serum AST and ALT activities and histopathological hepatic lesions, in a dose-dependent manner. Moreover, MDA and GSH levels and catalase, SOD, and GST activities in hepatic tissues were not affected by administration of CCl4, indicating that the pretreatment of PYC efficiently protects against CCl4-induced oxidative damage in rats. The results indicate that PYC has a protective effect against acute hepatotoxicity induced by the administration of CCl4 in rats, and that the hepatoprotective effects of PYC may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity. PMID:17900780

  19. Ameliorative effects of pycnogenol on carbon tetrachloride-induced hepatic oxidative damage in rats.

    PubMed

    Ahn, Tai-Hwan; Yang, Young-Su; Lee, Jong-Chan; Moon, Chang-Jong; Kim, Sung-Ho; Jun, Woojin; Park, Seung-Chun; Kim, Jong-Choon

    2007-11-01

    This study evaluated the putative antioxidant activity of Pycnogenol (PYC) against CCl4-induced hepatic oxidative damage in Sprague-Dawley rats. A single oral dose of CCl4 (1.25 mL/kg) produced significantly increased levels of serum aminotransferase (AST) and alanine aminotransferase (ALT) activities. In addition, increased malondialdehyde (MDA) concentration, reduced glutathione (GSH) content, and decreased catalase, superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities were observed in the hepatic tissues. However, concomitant administration with PYC (10 or 20 mg/kg) significantly improved CCl4-induced hepatic injury, as evidenced by the decline of serum AST and ALT activities in a dose dependent manner. Moreover, PYC reduced MDA concentration and increased GSH levels and catalase, SOD and GST activities in hepatic tissues, indicating that concomitant administration with PYC efficiently prevent the CCl4-induced oxidative damage in rats. The free radical scavenging assay showed that PYC has a dose-dependent scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. These results indicate that PYC has an antioxidant effect against CCl4-induced hepatic oxidative damage and is useful as a hepatoprotective agent against various liver diseases induced by oxidative stress. PMID:17886222

  20. TOXIC INTERACTIONS BETWEEN CARBON TETRACHLORIDE AND CHLOROFORM IN CULTURED RAT HEPATOCYTES

    EPA Science Inventory

    Primary cultures of adult rat hepatocytes were incubated (1.5-16 hr) with various concentrations of CC14 (<0.5 mM) and/or CHCl3 (<2.5 mM). gent dependent alterations in hepatocyte functions were assessed by measuring (1) [3H]choline incorporation into phosphatidylcholine (endopla...

  1. ENHANCED NEUROTOXICITY OF 3,3-IMINODIPROPIONITRILE FOLLOWING PRETREATMENT WITH CARBON TETRACHLORIDE IN THE RAT

    EPA Science Inventory

    The present work tested the hypothesis that IDPN must be metabolized by the liver to an active metabolite to neurotoxic. Thus a reduction in IDPN neurotoxicity would be expected when liver function is compromised. ale rats were given ip injections of saline, 100 (IDPN1) or 200 (I...

  2. 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.

  3. Aquilegia vulgaris extract attenuates carbon tetrachloride-induced liver fibrosis in rats.

    PubMed

    Jodynis-Liebert, Jadwiga; Adamska, Teresa; Ewertowska, Małgorzata; Bylka, Wiesława; Matławska, Irena

    2009-09-01

    Six groups of male Wistar rats were treated as follows: in groups II, III and V liver damage was induced by CCl(4) (per os, 1590 mg/kg b.w.day) given 2 days a week for 6 weeks; group III was treated simultaneously with ethanol extract of Aquilegia vulgaris (100 mg/kg b.w.day) for 6 weeks; group V with silymarin, positive control, at a dose of 100 mg/kg b.w.day for 6 weeks; and groups IV and VI received only the extract or silymarin, respectively. Microsomal lipid peroxidation in the liver increased following CCl(4) treatment by 61-213% and was not changed significantly by the extract. The effect of silymarin was more pronounced, 19-52% decrease in the lipid peroxidation level. Hepatic glutathione was depleted by 22% in CCl(4)-treated rats. The extract tested did not change this parameter. The activity of antioxidant enzymes was significantly reduced after CCl(4) administration, by 42-63%. Co-administration of the extract or silymarin resulted in significant increase in these enzymes activity; however, the basal level was not reached. Hepatic hydroxyproline concentration was elevated over 5-fold in comparison with controls. Co-administration of the extract or silymarin decreased the level of hydroxyproline by 66% and 55%, respectively. Activity of serum hepatic enzymes was elevated in rats treated with CCl(4) by 47-8700%. Both the extract and silymarin reduced significantly these enzymes' activity. The extract caused a fall in bilirubin and cholesterol level in rats treated with CCl(4) by 42% and 17%, respectively. Histopathological examination revealed less-severe fibrosis in rats co-administered the extract or silymarin when compared to animals treated with CCl(4) alone. PMID:19059770

  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. 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.

  6. 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

  7. Carbon tetrachloride and chlorofluorocarbons in the South Atlantic Ocean, 19°S

    NASA Astrophysics Data System (ADS)

    Wallace, Douglas W. R.; Beining, Peter; Putzka, Alfred

    1994-04-01

    Exploratory measurements of a suite of anthropogenic halocarbon compounds (CCl4, CCl2FCClF2 (CFC-113), CH3CCl3, CCl3F (CFC-11)) were made using a new analytical technique on RV Meteor cruise 15 along 19°S (World Ocean Circulation Experiment (WOCE) Line A9)) in the Atlantic Ocean during February-March 1991. A separate analytical system was used to determine CCl2F2 (CFC-12) and CCl3F (CFC-11). A limited number of CFC-113 profiles indicated that it was undetectable below 400-500 m. The CCl4 data indicate that the entire Brazil Basin contains readily measurable levels of CCl4 (>0.05 pmol kg-1), whereas the deep Angola Basin contains very low levels (≤0.02 pmol kg-1). Slightly higher levels were found close to the bottom in the deep Angola Basin: possibly an anthropogenic signature. In contrast, most of the deep Brazil Basin and all of the deep Angola Basin (>1000 m) had undetectable levels of CFC-11, CFC-12, and CFC-113. Preindustrial levels of CCl4 in the atmosphere were therefore negligible (atmospheric mixing ratio <0.1 pptv). CCl4/CFC-11 ratios are used to estimate apparent ages and dilution factors for the North Atlantic Deep Water and Antarctic Bottom Water. Whereas CCl4/CFC-11/CFC-12 levels are internally consistent in deep waters, suggesting near-conservative behavior, there is evidence for very rapid removal of CCl4 in the thermocline. Removal rates suggest that in addition to neutral hydrolysis, some other loss pathway must be involved.

  8. Therapeutic Potential of Ginger against Renal Injury Induced by Carbon Tetrachloride in Rats

    PubMed Central

    Hamed, Manal A.; Ali, Sanaa A.; Saba El-Rigal, Nagy

    2012-01-01

    The objective of this study was to evaluate the potential of successive ginger extracts (petroleum ether, chloroform, and ethanol) against nephrotoxicity induced by CCl4 in rats. The evaluation was done through measuring kidney antioxidant parameters: glutathione (GSH), lipid peroxides (LPO), and superoxide dismutase (SOD). Renal function test: urea, creatinine and serum protein values, were also evaluated. The work was extended to examine tissue inflammatory mediators, prostaglandin-E2 (PGE2), collagen content and the kidney histopathology. Severe alterations in all biomarkers were observed after injury with CCl4. Treatment with ginger extracts resulted in markedly decreased levels of LPO, PGE2, collagen and kidney function tests, while increased levels of GSH, SOD and serum protein were observed. In conclusion, extracts of ginger, particularly the ethanol, resulted in an attractive candidate for the treatment of nephropathy induced by CCl4 through scavenging free radicals, improved kidney functions, inhibition of inflammatory mediators, and normalizing the kidney histopathological architecture. Further studies are required in order to identify the molecules responsible of the pharmacological activity. PMID:22566780

  9. 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...

  10. Protection by pantethine, pantothenic acid and cystamine against carbon tetrachloride-induced hepatotoxicity in the rat.

    PubMed

    Nagiel-Ostaszewski, I; Lau-Cam, C A

    1990-02-01

    The daily ip administration of pantethine (500 mg/kg), pantothenic acid (100 mg/kg) or cystamine (50 mg/kg) for 5 days conferred significant protection against the hepatotoxic and peroxidative actions of a 0.5 mL/kg ip dose of CCl4 in rats. All three treatments lessened the increases in serum ALT and liver TBARS values, and the reductions in serum triglyceride levels, and prevented the development of hepatic steatosis caused by the halocarbon. Pantethine was found to offer the greatest protection. PMID:2333416

  11. Hepatoprotective effects of polymethoxyflavones against acute and chronic carbon tetrachloride intoxication.

    PubMed

    Kim, Tae-Won; Lee, Dong-Ryung; Choi, Bong-Keun; Kang, Hwan-Kyu; Jung, Ju-Young; Lim, Seol-Wa; Yang, Seung Hwan; Suh, Joo-Won

    2016-05-01

    In the present study, we explore the protective effects of Citrus aurantium L. extract (CAE) against acute and chronic CCl4-induced hepatotoxicity. The quantitative analysis of CAE was performed using HPLC-UV to determine the nobiletin content was approximately 27%. For the acute model, the male ICR mice were orally treated with water, silymarin (positive control, 200 mg/kg) and CAE (50 and 200 mg/kg) for 3 days prior to CCl4 (1 mL/kg, 50% v/v in olive oil) IP injection. For the chronic model (n = 6/group), the mice were treated with each treatment for 28 consecutive days and CCl4 (1 mL/kg, 20%) was injected twice a week. In both the acute and chronic models, the CCl4 alone treated group showed histopathologic alterations with a significantly increase in serum hepatic enzyme levels together with a disrupted anti-oxidative status. In contrast, the CAE treatments restored pathologic alterations and recovered the oxidative status by enhancing antioxidant enzymes and reducing lipid peroxidation levels. Furthermore, CAE enhanced nuclear factor E2-related factor 2 (Nrf2) and its related cytoprotective signals, including NAD(P)H quinone oxidoreductase 1, UDP-glucuronosyltransferase, and γ-glutamylcysteine synthetase. Taken together, the present study demonstrates that CAE exerts a protective effect against CCl4-induced hepatotoxicity with its anti-oxidant, anti-inflammatory, and anti-apoptotic activity. PMID:26980244

  12. Epidermal growth factor protects against carbon tetrachloride-induced hepatic injury.

    PubMed

    Berlanga, J; Caballero, M E; Ramirez, D; Torres, A; Valenzuela, C; Lodos, J; Playford, R J

    1998-03-01

    1. Epidermal growth factor (EGF) is known to protect the gastrointestinal tract against various noxious agents. Its potential value in preventing/ treating hepatic injury is, however, largely unexplored. We therefore examined whether EGF could influence CCl4-induced hepatic injury. 2. Female Sprague-Dawley rats (8 per group) received saline or recombinant EGF (500 or 750 micrograms/kg, intraperitoneal) 30 min before CCl4 (20% v/v, in olive oil, intraperitoneal). Eighteen hours later, animals were killed, serum was collected for assay of biochemical markers of hepatic injury and livers were removed for histological analyses. 3. Administration of CCl4 resulted in severe hepatic necrosis and caused a 10-fold rise in plasma alanine aminotransferase levels compared with levels seen in control animals (218 +/- 15 compared with 23 +/- 9 mumol/l in controls, mean +/- SEM, P < 0.01). Serum malondialdehyde levels, used as a marker of lipid peroxidation, showed a 2-fold rise in response to CCl4 treatment (median 4.0, quartile range 3.3-5.8 units/l compared with median 2.3, quartile range 2.1-2.5 units/l in controls, P < 0.05). Administration of EGF at 500 micrograms/kg, before the CCl4, did not protect against injury, as assessed by histology or rise in plasma alanine aminotransferase levels. In contrast, animals given EGF at 750 micrograms/kg, before the CCl4, had only minimal changes in histology, with only a minor rise in alanine aminotransferase levels (37 +/- 4 compared with 23 +/- 9 mumol/l in animals not given CCl4) and had no significant rise in malondialdehyde levels. 4. EGF protects against CCl4-induced hepatic injury and may provide a novel approach to the treatment of liver damage. PMID:9616254

  13. REDUCTION OF HEXACHLOROETHANE AND CARBON TETRACHLORIDE AT SURFACES OF BIOTITE, VERMICULITE, PYRITE, AND MARCASITE

    EPA Science Inventory

    Environmental factors significantly affect the transformation rates and the pathways of halogenated aliphatic compounds. e have studied the transformation of tetrachloromethane (CTET), and hexachloroethane (HCA) in homogenous and heterogenous systems designed to simulate groundwa...

  14. Isoliquiritigenin attenuates oxidative hepatic damage induced by carbon tetrachloride with or without buthionine sulfoximine.

    PubMed

    Zhao, ZhengLin; Park, Sang Mi; Guan, LiXin; Wu, YiYan; Lee, Jong Rok; Kim, Sang Chan; Kim, Young Woo; Zhao, RongJie

    2015-01-01

    Glycyrrhizae radix (G. radix) has been demonstrated to have hepatoprotective properties. This study determined the therapeutic effects of isoliquiritigenin (isoLQ) in G. radix, against liver injury induced by CCl4 in rats. CCl4 (0.5 ml/kg/d, twice) or CCl4 plus buthionine sulfoximine exerted severe liver damage assessed by increased plasma levels of alanine aminotransferase and aspartate aminotransferase, in addition to hepatic degeneration and necrosis. These pathological changes were markedly protected by pretreatment with isoLQ (5, 20 mg/kg/d, p.o.) for 3 consecutive days. In addition, pretreatment with isoLQ inhibited CCl4-induced reduction of cytochrome P450 2E1 protein and mRNA expression as well as activity in the liver. Moreover, isoLQ pretreatment reversed the decrease in hepatic antioxidant capacity induced by CCl4 as well as suppressed expression of tumor necrosis factor-alpha and cyclooxigenase-2 in the liver. These results suggest that isoLQ has a protective effect against CCl4-induced liver damage through induction of antioxidant and anti-inflammatory activities. PMID:25450236

  15. Diethylcarbamazine Reduces Chronic Inflammation and Fibrosis in Carbon Tetrachloride- (CCl4-) Induced Liver Injury in Mice

    PubMed Central

    Rocha, Sura Wanessa Santos; de França, Maria Eduarda Rocha; Rodrigues, Gabriel Barros; Barbosa, Karla Patrícia Sousa; Nunes, Ana Karolina Santana; Pastor, André Filipe; Oliveira, Anne Gabrielle Vasconcelos; Oliveira, Wilma Helena; Luna, Rayana Leal Almeida; Peixoto, Christina Alves

    2014-01-01

    This study investigated the anti-inflammatory effects of DEC on the CCl4-induced hepatotoxicity in C57BL/6 mice. Chronic inflammation was induced by i.p. administration of CCl4 0.5 μL/g of body weight through two injections a week for 6 weeks. DEC (50 mg/kg) was administered by gavage for 12 days before finishing the CCl4 induction. Histological analyses of the DEC-treated group exhibited reduced inflammatory process and prevented liver necrosis and fibrosis. Immunohistochemical and immunofluorescence analyses of the DEC-treated group showed reduced COX-2, IL1β, MDA, TGF-β, and αSMA immunopositivity, besides exhibiting decreased IL1β, COX-2, NFκB, IFNγ, and TGFβ expressions in the western blot analysis. The DEC group enhanced significantly the IL-10 expression. The reduction of hepatic injury in the DEC-treated group was confirmed by the COX-2 and iNOS mRNA expression levels. Based on the results of the present study, DEC can be used as a potential anti-inflammatory drug for chronic hepatic inflammation. PMID:25374445

  16. Removal of technetium, carbon tetrachloride, and metals from DOE properties. 1998 annual progress report

    SciTech Connect

    Mallouk, T.E.; Darab, J.G.; Ponder, S.M.

    1998-06-01

    'The objective of the project is to develop and characterize supported reducing agents, and solid waste forms derived from them, which will be effective in the removal of transition metal ions, chlorinated organic molecules, and technetium from aqueous mixed wastes. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (chromium, mercury, and lead) and rhenium (as a surrogate for technetium) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for the supported iron aggregates that will optimize their selectivity for the contaminants of interest. The support composition is of particular interest in the case of technetium (Tc) separation and stabilization in the Hanford tank wastes. While it is expected that pertechnetate will be reduced insoluble TcO{sub 2} , the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes. This report summarizes progress in the first 8 months of a 3-year collaborative project involving Penn State and Pacific Northwest National Laboratory (PNNL).'

  17. Study of AOT-stabilized microemulsions of urea dispersed in carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Ruggirello, A.; Turco Liveri, V.

    2003-03-01

    Measurements of some physico-chemical properties (density, viscosity, permittivity) of the urea/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/CCl 4 system as a function of the volume fraction of the dispersed phase (0< Φ<0.7) at various urea to AOT molar ratio ( Rurea) have been carried out at 25 °C. The experimental data analysis are consistent with the hypothesis that urea is entrapped as small-size molecular clusters within the hydrophilic core of the AOT reversed micelles and that this structure is preserved well above a threshold Φ value where a percolative transition occurs. Besides, X-ray diffraction spectra of samples at Φ=1, obtained by complete evaporation under vacuum of the apolar solvent of urea/AOT/CCl 4 solutions, indicates that, even in the typical two-dimensional hexagonal structure of AOT liquid crystals, urea is encapsulated as uni-dimensional molecular clusters.

  18. Late protective effects of the anticalmodulin drug fluphenazine on carbon tetrachloride-induced liver necrosis.

    PubMed

    de Ferreyra, E C; Bernacchi, A S; San Martin, M F; Castro, G D; Castro, J A

    1995-09-01

    Fluphenazine (FP) treatment (50 mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroxidation. FP lowered body temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts sufficient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature. PMID:8561921

  19. Nicotinamide late protective effects against carbon tetrachloride-induced liver necrosis.

    PubMed

    de Ferreyra, E C; Bernacchi, A S; San Martín, M F; Castro, G D; Castro, J A

    1994-06-01

    Nicotinamide (NIC) is known to increase the synthesis of pyridine nucleotides and also to inhibit the hydrolysis of them to ADP-ribose, which in turn is involved in Ca2+ release from mitochondria via the ADP ribosylation of crucial mitochondrial proteins. In this work, we test the potential ability of NIC to be a late protective agent against CCl4-induced liver necrosis. We observed that 1 g/kg po NIC, 30 min before or 6 or 10 hr after CCl4 (1 ml/kg), given ip as a 20% (v/v) solution in olive oil, was able to significantly prevent the necrogenic effect of the hepatotoxin at 24 hr as evidenced by determination of isocitric dehydrogenase activity in plasma or by histological observation. NIC administration 6 hr after CCl4 prevented fatty liver induced by hepatotoxin at 24 hr. NIC did not modify CCl4-induced lipid peroxidation process at 1 hr after CCl4 and decreased the covalent binding of 14CCl4 to lipids. NIC decreased the levels of 14CCl4 reaching the liver when given 30 min before hepatotoxin but not when given 6 hr after it. NIC lowered body temperature of rats at 1, 3, and 6 hr and augmented it at 24 hr after CCl4. NIC concentrations in liver as determined by GC/MS/SIM analysis were 21 micrograms/g liver 1 hr after administration and 53 micrograms/g at 3 hr. Late preventive effects of NIC against CCl4 induced liver necrosis when given at 6 or 10 hr after CCl4 are compatible with the hypothesis that NIC restores mitochondrial ability for Ca2+ uptake. This hypothesis remains to be proved and is being further challenged in our laboratory. PMID:7957779

  20. Trifluopromazine late preventive effects on carbon tetrachloride-induced liver necrosis.

    PubMed

    de Ferreyra, E C; Bernacchi, A S; San Martin, M F; Castro, G D; Castro, J A

    1995-04-01

    Trifluopromazine (TFPro) administration to rats (50 mg/kg, ip) 30 min before or 6 or 10 hr after CCl4 treatment (1 ml/kg ip in olive oil) partially prevented necrogenic effects of this compound at 24 hr. TFPro has only minor effects on the covalent binding (CB) of CCl4-reactive metabolites to cellular constituents and even an enhancing action on CCl4-promoted lipid peroxidation (LP). Determination of TFPro levels in liver 1 and 3 hr after administration by gas chromatography/mass spectrometry showed its presence in that tissue at concentrations well above those needed for calmodulin (CaM) inhibitory effects of this drug. TFPro lowered body temperature in CCl4-treated animals during the 24-hr observation period. Protective effects of TFPro at 6 or 10 hr, when most of the CB and all of the LP has already occurred, suggest but do not prove a role for CaM in late stages of CCl4-induced necrogenic effects. Decreases in the body temperature of CCl4-poisoned animals provoked by TFPro might also play a role in the preventive actions of this drug. PMID:8549698

  1. 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.

  2. Remediation and Reuse of Soils

    NASA Astrophysics Data System (ADS)

    Zihms, Stephanie; Switzer, Christine; Tarantino, Alessandro

    2013-04-01

    Links between contaminant remediation and impacts on soil properties have not been explored in a systematic way. Most remediation studies focus on the effectiveness of the remediation process. Contamination and remediation can have significant effects on soil properties and function. Considering that in most remediation cases the soil will be re-used in some way, it is important to understand the effects of the remediation process on soil properties and the post-remediation soil behaviour. This understanding can help to determine the best re-use of the soil and therefore improve post-remediation site development. Laboratory experiments on coal tar contaminated soil treated with smouldering remediation show that thermal treatments affect a variety of soil properties ranging from mineralogical composition, particle size distribution, and pH. Dynamic responses like permeability and shear strength are impacted as well and these responses are linked to the changes in soil properties. Soil permeability, capillary rise, and contact angle change dramatically after this remediation process, indicating some degree of hydrophobicity and significant implications for water movement through the post-remediation soil. The observed changes in permeability are linked to physical changes to the soil grain surface combined with small amounts (<1ppm) of coal tar and combustion product residue. Decoupling these effects is essential to understanding the extent of impact remediation processes have on long-term soil function. While chemical residue within the pores can be removed through "polishing" remediation steps, physical changes are likely to be permanent. Physical changes and chemical residue also have important implications with respect to the response of the soil under shear. These observed changes indicate that the remediated soil and its behaviour should be considered by remediation research. Monitoring of soil properties and behaviour during aggressive remediation can improve

  3. Lau Remedies Outlined.

    ERIC Educational Resources Information Center

    Cardenas, Jose A.

    The understanding of two principles is important if school districts are to develop comprehensive plans responsive to the Lau v. Nichols remedies specified by the Department of Health, Education, and Welfare (HEW) in ways that both adhere to the spirit of the Lau decision and allow the school district to develop coherent educational programs for…

  4. 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…

  5. 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…

  6. 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...

  7. Developing Remedial Mathematics Strategies.

    ERIC Educational Resources Information Center

    Sadowski, Barbara R.

    The paper describes strategies for remediating mathematics difficulties (particularly the process of regrouping or "borrowing" in whole number subtraction) in children. Three interrelated aspects of the process (the meaning of subtraction, understanding of non-standard numerals, and the function of the subtraction algorithm), are considered. The…

  8. [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

  9. 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.

  10. 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. PMID:24106890

  11. 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.

  12. 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.

  13. Remedial Action Assessment System

    Energy Science and Technology Software Center (ESTSC)

    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

  14. CENTRAL PLATEAU REMEDIATION

    SciTech Connect

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  15. 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

  16. Environmental remediation monitoring using chemical sensors

    SciTech Connect

    Dong X. Li

    1996-12-31

    Monitoring is one of the most critical steps in environmental site remediation. However, the conventional technique of monitoring {open_quotes}inlet{close_quotes} and {open_quotes}outlet{close_quotes} of a process stream is no longer applicable in many in-situ remedial processes such as bioventing, biosparging, and intrinsic bioremediation. Traditional soil sampling and analysis is also unsuitable for monitoring biodegradation process because of chemical and biological inhomogeneity in soil. Soil gas measurement, on the other hand, is one of the few techniques available which is ideally suited for monitoring in-situ processes, since bioremediation processes involve gaseous components such as oxygen and carbon dioxide. In addition to oxygen and carbon dioxide, contaminant vapors and other trace gaseous components found in the pores of unsaturated soils also provide information on the spatial distribution and the extent of biodegradation. These gaseous components are very mobile, which are ideal analytes for chemical sensors. In this study, oxygen, carbon dioxide, and hydrocarbon subsurface chemical sensors were employed for monitoring in-situ bioremediation of petroleum hydrocarbon contaminated soils.

  17. 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...

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. 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. PMID:27157934

  5. 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.

  6. 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

  7. 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

  8. Common herbal remedies.

    PubMed

    Turkoski, B B

    2000-01-01

    Herbal remedies are becoming increasingly popular as people seek more effective, natural, or safer methods for treating a variety of complaints. As a result, nurses in every setting may expect to see increased numbers of patients who are using herbal products. When patients assume that the nurses will be critical of their use of herbals, they may withhold such information to avoid unpleasantness. This could place patients at risk for adverse effects, drug interactions, and complications related to ineffective treatment. Nurses who are knowledgeable about herbal products and who are open to discussion about these products can provide information and advice about safe use. The discussion in this article addresses actions, possible benefits, and dangers of the most common herbal products. Guidelines for assessing and teaching clients about herbal use are included. PMID:11062629

  9. Remediation of Estuarine Barrages

    NASA Astrophysics Data System (ADS)

    Worrall, F.; Lamping, J.; Wright, J.

    2003-04-01

    Estuarine barrages have become a popular component of urban regeneration in the UK. However, a range of problems have been identified with the construction and operation of barrages, including: excess sediment build up; low oxygen conditions and eutrophication. This project has examined 3 strategies for the remediation of estuarine barrages: use of aerators; flushing of the impoundment by lock management; and use of boom/skirt technologies. The results show that: flushing of the barrage is ineffective; and that boom/skirt technologies could be successful in stratified impoundments. Aerators were shown to give significant increases in dissolved oxygen levels and field studies were able to delimit times when aeration would be effective. The study has shown that most problems experienced by the barrage are the result of inputs to the barrage rather than caused by the internal processes of the barrage itself and as such esturies must be managed as part of the catchment as a whole.

  10. Overview of lead remediation effectiveness.

    PubMed

    Elias, Robert W; Gulson, Brian

    2003-02-15

    A Symposium on Lead Remediation Effectiveness, sponsored by the US Environmental Protection Agency, was held at Coeur d'Alene, Idaho, USA from 22-25 May, 2000. International participants from various levels of government, educational institutions, industry, and community representatives presented papers and posters on themes that ranged from engineering practices through community participation in the remediation processes. The papers in this volume represent a global distribution of sites, especially those outside the USA. In providing an overview of the symposium and the theme of Lead Remediation Effectiveness we have drawn on information from some presentations at the symposium, besides those described in this volume. PMID:12568760

  11. 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…

  12. 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.

  13. REMEDIAL ACTION COSTING PROCEDURES MANUAL

    EPA Science Inventory

    The manual provides specific procedures for the cost estimating and economic analysis steps required for preparing engineering cost estimates for selecting remedial action alternatives in response to the requirements of the Comprehensive Environmental Response, Compensation, and ...

  14. Teacher Burnout: Diagnosis, Prevention, Remediation.

    ERIC Educational Resources Information Center

    Kossack, Sharon W.; Woods, Sandra L.

    1980-01-01

    Practical suggestions for diagnosing, preventing, and remediating teacher burnout include changing the school environment, health habits, supportive behavior, time management, and general perspective on teaching and job situations. (JD)

  15. 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