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Antibodies to benzo(a)pyrene were produced by coupling the carcinogen to bovine serum albumin and immunizing New Zealand white rabbits and Fischer rats with the conjugate. Sera was collected from blood samples and assayed to deter...
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Antibodies to benzo(a)pyrene were produced by coupling the carcinogen to bovine serum albumin and immunizing New Zealand white rabbits and Fischer rats with the conjugate. Sera was collected from blood samples and assayed to determine antibody titer using the following procedures: Ouchterlony double diffusion, passive hemagglutination, and an enzyme immunoassay (EIA). Results showed significant antibody titer, the highest found in samples taken from our subcutaneously injected rabbit. Sera from this rabbit showed a titer of 1/256 in the hemagglutination assay and a titer of 1/15,625 in the EIA. Isolated specific antibodies will be used in the development of fluoroimmuno sensor. 21 references, 4 figures, 3 tables. (ERA citation 10:017078)
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We have examined a number of coal-derived liquids for their carcinogenic activity in attempts to compare the relative potencies of liquids derived from various processes and identified the components responsible for the carcinogen...
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We have examined a number of coal-derived liquids for their carcinogenic activity in attempts to compare the relative potencies of liquids derived from various processes and identified the components responsible for the carcinogenic activity. Fractionation appeared to increase the activity. Activities of the materials tested did not necessarily reflect the levels of known carcinogens such as benzo(a)pyrene (BaP), nor were they simple summations of the biological activities of individual components. These observations suggest that there are interactions among components of these complex mixtures which influence the response of the animal to the carcinogenic constituents. Data obtained in our laboratory indicate that known mutagens and carcinogens contained in complex mixtures derived from coal may show either suppressed or enhanced activity depending upon the composition of the mixture. (ERA citation 11:025328)
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In this work we have investigated the performance of an antibody-based fiberoptics sensor for the detection of the carcinogen benzo(a)pyrene and its DNA-adduct product BP-tetrol. The excellent sensitivity of this device - femtomol...
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In this work we have investigated the performance of an antibody-based fiberoptics sensor for the detection of the carcinogen benzo(a)pyrene and its DNA-adduct product BP-tetrol. The excellent sensitivity of this device - femtomole limits of detection for BP - illustrates that it has considerable potential to perform analyses of chemical and biological samples at trace levels in complex matrices. The results indicate that fiberoptics-based fluoroimmunosensors can be useful in a wide spectrum of biochemical and clinical analyses.
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The goal of this project was to develop new spectroscopic techniques and to adapt existing methods for studies of the interactions of polycyclic aromatic mutagens and carcinogens with nucleic acids. A highly sensitive, computer-in...
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The goal of this project was to develop new spectroscopic techniques and to adapt existing methods for studies of the interactions of polycyclic aromatic mutagens and carcinogens with nucleic acids. A highly sensitive, computer-interfaced linear dichroism system was constructed to allow for studies of the conformations of carcinogen-DNA non-covalent complexes and covalent adducts. Fluorescence techniques were adapted for studies of the heterogeneities of carcinogen-DNA adducts utilizing fluorescence emission spectra, and detailed comparisons between excitation and absorption spectra acquired with digital instrumentation. Detailed fluorescence quenching studies, together with accurate determinations of fluorescence decay profiles utilizing the National Synchrotron Light Source at the Brookhaven National Laboratory, allowed for a determination of the solvent exposure of the polycyclic aromatic moieties in covalent carcinogen-DNA adducts. Finally, a detailed study of the base-sequence dependence of non-covalent intercalation complex formation and chemical reactivity of polycyclic aromatic diol epoxide with synthetic polynucleotides was performed. These studies provided insight into the detailed mechanisms of interaction of benzo(a)pyrene trans-7,8-dihydrodiol-9,10-epoxide with DNA.
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Minimized semi-empirical potential energy calculations for a number of carcinogen adducts with dCpdG have yielded molecular views of the adduct conformations. The base displaced and Z type conformations of acetylaminofluorene (AAF...
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Minimized semi-empirical potential energy calculations for a number of carcinogen adducts with dCpdG have yielded molecular views of the adduct conformations. The base displaced and Z type conformations of acetylaminofluorene (AAF) adducts to guanine C-8 have been detailed. Model building shows that base displacement causes kinking and denaturation in the B helix, while the Z helix is largely unperturbed by modification with AAF, in agreement with experimental findings. The minor AAF adduct linked to quanine N exp 2 can reside at a B-Z junction, with the carcinogen buried in a groove in the Z direction, without causing denaturation. The syn guanine in these modified Z forms could be mutagenic, the lesion escaping repair because the helix is undeformed, while the distorted base-displaced conformers are repaired. Aminofluorene (AF) and 4-aminobiphenyl (ABP) linked to guanine N exp 2 are currently believed to be critical lesions. They all have a pair of A or B type low energy states, one of which has base-base stacking with carcinogen at the helix exterior, and a second with carcinogen-base stacking. The two states are easily interconvertible. It is possible that the carcinogen may reside primarily at the unperturbed helix exterior where it escapes repair, but that carcinogen-base stacking may occur at a critical time during replication, leading to a mutation. 49 references, 8 figures. (ERA citation 09:050587)
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The interaction of benzo(e)pyrene, an atmospheric pollutant formed during the burning of organic materials, and bovine serum albumin (BSA) was studied to determine a pyrene-type metabolite is formed. (ERA citation 06:006491)
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This report focuses on the performance of a Kratos TOF-SIMS reflectron-based mass spectrometer equipped with a liquid metal ion gun. The analyzer exhibits a nominal mass resolution of better than 1 part in 10,000 with a transmissi...
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This report focuses on the performance of a Kratos TOF-SIMS reflectron-based mass spectrometer equipped with a liquid metal ion gun. The analyzer exhibits a nominal mass resolution of better than 1 part in 10,000 with a transmission of about 50%. The secondary ion extraction optics has been optimized for laser postionization where there is a large ionization volume, and for SIMS where the ions originate from a point source on the surface. Experiments with benzopyrene have suggested that it is possible to improve upon the ionization efficiency of molecular species by moving into the subpicosecond regime.
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A direct, specific mass spectrometric method useful for determination of polycyclic aromatic adducts has been developed. The experiments indicated that overall recoveries from the acid hydrolysis, isolation and derivatization step...
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A direct, specific mass spectrometric method useful for determination of polycyclic aromatic adducts has been developed. The experiments indicated that overall recoveries from the acid hydrolysis, isolation and derivatization steps will be about 50%. It is apparent that a method even for BaP adducts is not yet complete. The methods described in the paper are provided in detail. Other derivatization techniques are needed that are selective and quantitative, and that will enhance the singal in the mass spectrometer to improve instrument selectivity and sensitivity. In addition to improvements in instrument sensitivity and gas chromatography column performance, there is a great need for procedures for rigorous documentation of organic analytical methods at the picogram level. 12 refs., 2 tabs. (ERA citation 13:019665)
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Previous linear dichroism measurements suggested that the (-)BPDE-DNA adducts are characterized by considerable interactions between the pyrene residue and the DNA bases. Such a conformation is consistent with intercalation, or pa...
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Previous linear dichroism measurements suggested that the (-)BPDE-DNA adducts are characterized by considerable interactions between the pyrene residue and the DNA bases. Such a conformation is consistent with intercalation, or partial intercalation. With the pyrene residue thus protected from the solvent environment, one might expect a low degree of accessibility to acrylamide quencher molecules. Since the fluorescence of these (-)BPDE-DNA adducts is indeed insensitive to acrylamide, the quenching results reported here are consistent with such a conformation. The covalent adducts derived from the binding of (+)BPDE to DNA appear to be 70% accessible to acrylamide, suggesting that a majority of these adducts reside at external binding sites, or in a locally disordered region of the DNA double helix. Again, these conclusions derived from the fluorescence quenching data are consistent with our previous linear dichroism results. 3 refs., 3 figs. (ERA citation 12:002012)
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This study reports the chromatographic properties of sulfate, glucuronide and GSH conjugates on a Dupont C-8 column by HPLC. The analytical conditions were developed with standard BaP conjugates and were utilized to chromatograph ...
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This study reports the chromatographic properties of sulfate, glucuronide and GSH conjugates on a Dupont C-8 column by HPLC. The analytical conditions were developed with standard BaP conjugates and were utilized to chromatograph aqueous-soluble metabolites from HEF metabolism after removal of organic-soluble metabolites. 30 refs., 5 figs., 2 tabs. (ERA citation 10:047403)
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