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Sample records for bpde-like dna adduct

  1. Carcinogenic adducts induce distinct DNA polymerase binding orientations

    Science.gov (United States)

    Vrtis, Kyle B.; Markiewicz, Radoslaw P.; Romano, Louis J.; Rueda, David

    2013-01-01

    DNA polymerases must accurately replicate DNA to maintain genome integrity. Carcinogenic adducts, such as 2-aminofluorene (AF) and N-acetyl-2-aminofluorene (AAF), covalently bind DNA bases and promote mutagenesis near the adduct site. The mechanism by which carcinogenic adducts inhibit DNA synthesis and cause mutagenesis remains unclear. Here, we measure interactions between a DNA polymerase and carcinogenic DNA adducts in real-time by single-molecule fluorescence. We find the degree to which an adduct affects polymerase binding to the DNA depends on the adduct location with respect to the primer terminus, the adduct structure and the nucleotides present in the solution. Not only do the adducts influence the polymerase dwell time on the DNA but also its binding position and orientation. Finally, we have directly observed an adduct- and mismatch-induced intermediate state, which may be an obligatory step in the DNA polymerase proofreading mechanism. PMID:23814187

  2. Phosphotriester adducts (PTEs): DNA's overlooked lesion.

    Science.gov (United States)

    Jones, George D D; Le Pla, Rachel C; Farmer, Peter B

    2010-01-01

    In addition to reacting with DNA base moieties, many chemical genotoxins also react with the oxygen atoms of the internucleotidic phosphodiester linkages to form phosphotriester adducts (PTEs). In view of their stability under physiological conditions, it has been suggested that PTEs may be useful biomarkers for measuring cumulative genotoxin exposure. The methodology for their determination is varied and still not completely developed but includes determination of hydrolysis products and (32)P-postlabelling approaches. More recently, transalkylation and direct mass spectrometry techniques have been devised, which give extra chemical information on the structures of the PTEs. The proportion of DNA damage formed as PTEs is much greater with SN1 compared to SN2 alkylating agents, and it has been shown in DNA that the formation of PTEs is partially sequence dependent. PTEs have been considered to be refractory to repair in mammalian cells but repair mechanisms have been found in prokaryotic cells, e.g. PTEs in Escherichia coli are repaired by O(6)-methylguanine-DNA methyltransferase (O(6)-MGT or Ada protein). However, studies on in vivo persistence of PTEs in mammalian systems have not ruled out the possibility of a contribution from an active repair process for PTEs. The biological significance of PTEs is largely unstudied and unknown, although effects of PTEs on DNA polymerases, and some exo- and endonucleases have been observed. Also site-specific PTEs impair the repair processing of adjacent sites of DNA damage, which may be a biological mechanism of importance for these lesions. In this review, we will consider the analytical methods available for the determination of PTEs, their stability in vitro and in vivo, the mechanisms for their repair, their possible biological significance and their potential role as biomarkers in human molecular epidemiology studies.

  3. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yun-bo

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs.

  4. Paclitaxel Enhances Carboplatin-DNA Adduct Formation and Cytotoxicity.

    Science.gov (United States)

    Jiang, Shuai; Pan, Amy W; Lin, Tzu-yin; Zhang, Hongyong; Malfatti, Michael; Turteltaub, Kenneth; Henderson, Paul T; Pan, Chong-xian

    2015-12-21

    This rapid report focuses on the pharmacodynamic mechanism of the carboplatin/paclitaxel combination and correlates it with its cytotoxicity. Consistent with the synergistic to additive antitumor activity (the combination index ranging from 0.53 to 0.94), cells exposed to this combination had significantly increased carboplatin-DNA adduct formation when compared to that of carboplatin alone (450 ± 30 versus 320 ± 120 adducts per 10(8) nucleotides at 2 h, p = 0.004). Removal of paclitaxel increased the repair of carboplatin-DNA adducts: 39.4 versus 33.1 adducts per 10(8) nucleotides per hour in carboplatin alone (p = 0.021). This rapid report provides the first pharmacodynamics data to support the use of carboplatin/paclitaxel combination in the clinic.

  5. Linking the generation of DNA adducts to lung cancer.

    Science.gov (United States)

    Ceppi, Marcello; Munnia, Armelle; Cellai, Filippo; Bruzzone, Marco; Peluso, Marco E M

    2017-09-01

    Worldwide, lung cancer is the leading cause of cancer death. DNA adducts are considered a reliable biomarker that reflects carcinogen exposure to tobacco smoke, but the central question is what is the relationship of DNA adducts and cancer? Therefore, we investigated this relationship by a meta-analysis of twenty-two studies with bronchial adducts for a total of 1091 subjects, 887 lung cancer cases and 204 apparently healthy individuals with no evidence of lung cancer. Our study shows that these adducts are significantly associated to increase lung cancer risk. The value of Mean Ratiolung-cancer (MR) of bronchial adducts resulting from the random effects model was 2.64, 95% C.I. 2.00-3.50, in overall lung cancer cases as compared to controls. The significant difference, with lung cancer patients having significant higher levels of bronchial adducts than controls, persisted after stratification for smoking habits. The MRlung-cancer value between lung cancer patients and controls for smokers was 2.03, 95% C.I. 1.42-2.91, for ex-smokers 3.27, 95% C.I. 1.49-7.18, and for non-smokers was 3.81, 95% C.I. 1.85-7.85. Next, we found that the generation of bronchial adducts is significantly related to inhalation exposure to tobacco smoke carcinogens confirming its association with volatile carcinogens. The MRsmoking estimate of bronchial adducts resulting from meta-regression was 2.28, 95% Confidence Interval (C.I.) 1.10-4.73, in overall smokers in respect to non-smokers. The present work provides strengthening of the hypothesis that bronchial adducts are not simply relate to exposure, but are a cause of chemical-induced lung cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Chemistry and Biology of Aflatoxin-DNA Adducts

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Michael P.; Banerjee, Surajit; Brown, Kyle L.; Egli, Martin (Vanderbilt)

    2012-03-27

    Aspergillus flavus is a fungal contaminant of stored rice, wheat, corn, and other grainstuffs, and peanuts. This is of concern to human health because it produces the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}), which is genotoxic and is implicated in the etiology of liver cancer. AFB{sub 1} is oxidized in vivo by cytochrome P450 to form aflatoxin B{sub 1} epoxide, which forms an N7-dG adduct (AFB{sub 1}-N7-dG) in DNA. The latter rearranges to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative that equilibrates between {alpha} and {beta} anomers of the deoxyribose. In DNA, both the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts intercalate above the 5'-face of the damaged guanine. Each produces G {yields} T transversions in Escherichia coli, but the AFB{sub 1}-{beta}-FAPY adduct is more mutagenic. The Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) provides a model for understanding error-prone bypass of the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts. It bypasses the AFB{sub 1}-N7-dG adduct, but it conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including mis-insertion of dATP, consistent with the G {yields} T mutations characteristic of AFB{sub 1} mutagenesis in E. coli. Crystallographic analyses of a series of binary and ternary complexes with the Dpo4 polymerase revealed differing orientations of the N7-C8 bond of the AFB{sub 1}-N7-dG adduct as compared to the N{sup 5}-C8 bond in the AFB{sub 1}-{beta}-FAPY adduct, and differential accommodation of the intercalated AFB{sub 1} moieties within the active site. These may modulate AFB{sub 1} lesion bypass by this polymerase.

  7. Stability of acetaldehyde-derived DNA adduct in vitro.

    Science.gov (United States)

    Hori, Kimiko; Miyamoto, Shin'ichi; Yukawa, Yoshiyuki; Muto, Manabu; Chiba, Tsutomu; Matsuda, Tomonari

    2012-07-13

    Acetaldehyde (AA) derived from alcoholic beverages is a confirmed carcinogen for esophageal and head and neck cancers. AA forms various DNA adducts and is thought to play a crucial role in carcinogenesis. Transient DNA adducts are usually repaired, but the stability of AA-derived DNA adducts has not been elucidated. We investigated the stability of N(2)-ethylidene-2'-deoxyguanosine (N(2)-ethylidene-dG), a major AA-derived DNA adduct, in cultured cells. First, to determine the optimal concentration of AA for detecting N(2)-ethylidene-dG in cell culture, a dose-response study was performed using HL60 cells of the human promyelocytic leukemia cell line. An AA concentration ≥ 0.01% (1.8 mM) was required to detect N(2)-ethylidene-dG in vitro. We next examined the stability of N(2)-ethylidene-dG. After a 1 or 2h exposure to 0.01% of AA in a tightly sealed bottle, N(2)-ethylidene-dG content was measured by sensitive liquid chromatography tandem mass spectrometry immediately, 24h, and 48 h after exposure. After the 1h exposure, the mean (± SD) N(2)-ethylidene-dG contents were 12.1 ± 1.28, 8.20 ± 0.64, and 6.70 ± 0.52 adducts per 10(7) bases at each postexposure time. After the 2h exposure, N(2)-ethylidene-dG content increased to 21.4 ± 7.50, 10.5 ± 3.61, and 9.83 ± 3.90 adducts per 10(7) bases at each postexposure time. The half-life of this adduct was calculated as ∼35 h in independent experiments. These results indicate that AA exposure from daily alcohol consumption may cause DNA damage and may increase the risk of alcohol-related carcinogenesis. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Specific incorporation of an artificial nucleotide opposite a mutagenic DNA adduct by a DNA polymerase.

    Science.gov (United States)

    Wyss, Laura A; Nilforoushan, Arman; Eichenseher, Fritz; Suter, Ursina; Blatter, Nina; Marx, Andreas; Sturla, Shana J

    2015-01-14

    The ability to detect DNA modification sites at single base resolution could significantly advance studies regarding DNA adduct levels, which are extremely difficult to determine. Artificial nucleotides that are specifically incorporated opposite a modified DNA site offer a potential strategy for detection of such sites by DNA polymerase-based systems. Here we investigate the action of newly synthesized base-modified benzimidazole-derived 2'-deoxynucleoside-5'-O-triphosphates on DNA polymerases when performing translesion DNA synthesis past the pro-mutagenic DNA adduct O(6)-benzylguanine (O(6)-BnG). We found that a mutated form of KlenTaq DNA polymerase, i.e., KTqM747K, catalyzed O(6)-BnG adduct-specific processing of the artificial BenziTP in favor of the natural dNTPs. Steady-state kinetic parameters revealed that KTqM747K catalysis of BenziTP is 25-fold more efficient for template O(6)-BnG than G, and 5-fold more efficient than natural dTMP misincorporation in adduct bypass. Furthermore, the nucleotide analogue BenziTP is required for full-length product formation in O(6)-BnG bypass, as without BenziTP the polymerase stalls at the adduct site. By combining the KTqM747K polymerase and BenziTP, a first round of DNA synthesis enabled subsequent amplification of Benzi-containing DNA. These results advance the development of technologies for detecting DNA adducts.

  9. Formation and persistence of arylamine DNA adducts in vivo.

    OpenAIRE

    Beland, F A; Kadlubar, F F

    1985-01-01

    Aromatic amines are urinary bladder carcinogens in man and induce tumors at a number of sites in experimental animals including the liver, mammary gland, intestine, and bladder. In this review, the particular pathways involved in the metabolic activation of aromatic amines are considered as well as the specific DNA adducts formed in target and nontarget tissue. Particular emphasis is placed on the following compounds: 1-naphthylamine, 2-naphthylamine, 4-aminobiphenyl, 4-acetylaminobiphenyl, 4...

  10. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Myungkoo [Iowa State Univ., Ames, IA (United States)

    1995-12-06

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ~25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G2 or G3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N2-dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N2-dG.

  11. Estrogen-DNA Adducts as Novel Biomarkers for Ovarian Cancer Risk and for Use in Prevention

    Science.gov (United States)

    2013-03-01

    unbalanced, leading to formation of higher levels of catechol estrogen quinones , which react with DNA to form adducts. A low ratio indicates that a...polymorphisms and risk of hormonal cancers. The estrogen quinone resulting from CYP1B1 activity may proceed to adduct formation in the presence of...person’s estrogen metabolism is balanced, and formation of estrogen-DNA adducts is relatively low. Figure 1. Ratios of depurinating estrogen-DNA

  12. Temporal and spatial features of the formation of DNA adducts in sulfur mustard-exposed skin

    Energy Technology Data Exchange (ETDEWEB)

    Batal, Mohamed [Laboratoire «Lésions des Acides Nucléiques», Université Joseph Fourier – Grenoble 1, CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); Boudry, Isabelle; Mouret, Stéphane; Wartelle, Julien; Emorine, Sandy; Bertoni, Marine [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); Bérard, Izabel [Laboratoire «Lésions des Acides Nucléiques», Université Joseph Fourier – Grenoble 1, CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Cléry-Barraud, Cécile [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); and others

    2013-12-15

    Sulfur mustard (SM) is a chemical warfare agent that targets skin where it induces large blisters. DNA alkylation is a critical step to explain SM-induced cutaneous symptoms. We determined the kinetics of formation of main SM–DNA adducts and compare it with the development of the SM-induced pathogenesis in skin. SKH-1 mice were exposed to 2, 6 and 60 mg/kg of SM and treated skin was biopsied between 6 h and 21 days. Formation of SM DNA adducts was dose-dependent with a maximum immediately after exposure. However, adducts were persistent and still detectable 21 days post-exposure. The time-dependent formation of DNA adducts was also found to be correlated with the appearance of apoptotic cells. This temporal correlation suggests that these two early events are responsible for the severity of the damage to the skin. Besides, SM–DNA adducts were also detected in areas located next to contaminated zone, thus suggesting that SM diffuses in skin. Altogether, this work provides for the first time a clear picture of SM-induced genotoxicity using DNA adducts as a marker. - Highlights: • Sulfur mustard adducts are formed in DNA after skin exposure. • DNA damage formation is an early event in the pathological process of skin burn. • The amount of SM–DNA adducts is maximal at the earliest time point investigated. • Adducts are still detected 3 weeks after exposure. • Sulfur mustard diffuses in skin especially when large doses are applied.

  13. Formation and persistence of arylamine DNA adducts in vivo.

    Science.gov (United States)

    Beland, F A; Kadlubar, F F

    1985-01-01

    Aromatic amines are urinary bladder carcinogens in man and induce tumors at a number of sites in experimental animals including the liver, mammary gland, intestine, and bladder. In this review, the particular pathways involved in the metabolic activation of aromatic amines are considered as well as the specific DNA adducts formed in target and nontarget tissue. Particular emphasis is placed on the following compounds: 1-naphthylamine, 2-naphthylamine, 4-aminobiphenyl, 4-acetylaminobiphenyl, 4-acetylamino-4'-fluorobiphenyl, 3,2'-dimethyl-4-aminobiphenyl, 2-acetylaminofluorene, benzidine, N-methyl-4-aminoazobenzene, 4-aminoazobenzene, and 2-acetylaminophenanthrene. PMID:4085422

  14. Detection of adducts formed upon treatment of DNA with cisplatin and carboplatin

    NARCIS (Netherlands)

    Fichtinger-Schepman, A.M.J.; Welters, M.J.P.; Dijk-Knijnenburg, H.C.M. van; Sterre, M.L.T. van der; Tilby, M.J.; Berends, F.; Baan, R.A.

    1996-01-01

    In order to determine the nature of the cytotoxic lesion(s) formed by the antitumour drugs cisplatin and carboplatin, a comparative study was made of bifunctional DNA-adduct formation by these drugs. The kinetics of bifunctional cisplatin adduct formation were studied with DNA in vitro and in

  15. Detection and quantification of 4-ABP adducts in DNA from bladder cancer patients.

    Science.gov (United States)

    Zayas, Beatriz; Stillwell, Sara W; Wishnok, John S; Trudel, Laura J; Skipper, Paul; Yu, Mimi C; Tannenbaum, Steven R; Wogan, Gerald N

    2007-02-01

    We analyzed bladder DNA from 27 cancer patients for dG-C8-4-aminobiphenyl (dG-C8-ABP) adducts using the liquid chromatography tandem mass spectrometry method with a 700 attomol (1 adduct in 10(9) bases) detection limit. Hemoglobin (Hb) 4-aminobiphenyl (4-ABP) adduct levels were measured by gas chromatography-mass spectrometry. After isolation of dG-C8-ABP by immunoaffinity chromatography and further purification, deuterated (d9) dG-C8-ABP (MW=443 Da) was added to each sample. Structural evidence and adduct quantification were determined by selected reaction monitoring, based on the expected adduct ion [M+H+]+1, at m/z 435 with fragmentation to the product ion at m/z 319, and monitoring of the transition for the internal standard, m/z 444-->328. The method was validated by analysis of DNA (100 microg each) from calf thymus; livers from ABP-treated and untreated rats; human placentas; and TK6 lymphoblastoid cells. Adduct was detected at femtomol levels in DNA from livers of ABP-treated rats and calf thymus, but not in other controls. The method was applied to 41 DNA samples (200 microg each) from 27 human bladders; 28 from tumor and 14 from surrounding non-tumor tissue. Of 27 tissues analyzed, 44% (12) contained 5-80 dG-C8-ABP adducts per 10(9) bases; only 1 out of 27 (4%) contained adduct in both tumor and surrounding tissues. The Hb adduct was detected in samples from all patients, at levels of 12-1960 pg per gram Hb. There was no correlation between levels of DNA and Hb adducts. The presence of DNA adducts in 44% of the subjects and high levels of Hb adducts in these non-smokers indicate environmental sources of exposure to 4-ABP.

  16. Genetic polymorphisms in catalase and CYP1B1 determine DNA adduct formation by bento(a)pyrene ex vivo

    NARCIS (Netherlands)

    Schults, Marten A.; Chiu, Roland K.; Nagle, Peter; Kleinjans, J C; van Schooten, Frederik Jan; Godschalk, Roger W.

    Genetic polymorphisms can partially explain the large inter-individual variation in DNA adduct levels following exposure to polycyclic aromatic hydrocarbons. Effects of genetic polymorphisms on DNA adduct formation are difficult to assess in human studies because exposure misclassification

  17. Base-Resolution Analysis of Cisplatin–DNA Adducts at the Genome Scale

    OpenAIRE

    Shu, Xiaoting; Xiong, Xushen; Song, Jinghui; He, Chuan; Yi, Chengqi

    2016-01-01

    Cisplatin, one of the most widely used anticancer drugs, crosslinks DNA and ultimately induces cell death. However, the genomic pattern of cisplatin–DNA adducts has remained unknown owing to the lack of a reliable and sensitive genome-wide method. Herein we present “cisplatin-seq” to identify genome-wide cisplatin crosslinking sites at base resolution. Cisplatin-seq reveals that mitochondrial DNA is a preferred target of cisplatin. For nuclear genomes, cisplatin–DNA adducts are enriched withi...

  18. Aromatic DNA adducts in human white blood cells and skin after dermal application of coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Godschalk, R.W.L.; Ostertag, J.U.; Moonen, E.J.C.; Neumann, H.A.M.; Kleinjans, J.C.S.; Schooten, F.J. van [University of Maastricht, Maastricht (Netherlands). Dept. of Health Risk Analysis and Toxicology

    1998-09-01

    A group of eczema patients topically treated with coal tar (CT) ointments was used as a model population to examine the applicability of DNA adducts in white blood cell (WBC) subpopulations as a measure of dermal exposure to polycyclic aromatic hydrocarbons (PAHs). Aromatic DNA adducts were examined by {sup 32}P-postlabeling in exposed skin and WBC subsets, and urinary excretion of PAH metabolites was determined to assess the whole-body burden. The median urinary excretion of 1-hydroxypyrene and 3-hydroxybenzo(a)pyrene was 0.39 and 0.01 {mu}mol/mol creatinine respectively, before the dermal application of CT ointments. After treatment for 1 week, these levels increased to 139.7 and 1.18 {mu}mol/mol creatinine respectively, indicating that considerable amounts of PAHs were absorbed. Median aromatic DNA adduct levels were significantly increased in skin from 2.9 adduct/10{sup 8} nucleotides before treatment to 63.3 adducts/10{sup 8} nt after treatment with CT, in monocytes from 0.28 to 0.86 adducts/10{sup 8} nt, in lymphocytes from 0.33 to 0.89 adducts/10{sup 8} nt and in granulocytes from 0.28 to 0.54 adducts/10{sup 8} nt. A week after stopping the CT treatment, the DNA adduct levels in monocytes and granulocytes were reduced to 0.38 and 0.38 adducts/10{sup 8} nt respectively, whereas the adduct levels in lymphocytes remained enhanced. Total DNA adduct levels in skin correlated with the adduct levels in monocytes and lymphocytes. Excretion of urinary metabolites during the first week of treatment was correlated with the percentage of the skin surface treated with CT ointment and decreased within a week after the cessation of treatment. 3-Hydroxybenzo(a)pyrene excretion, correlated with the levels of DNA adducts in skin that comigrated with benzo(a)pyrene-diol-epoxide-DNA. This study indicates that the DNA adduct levels in mononuclear WBCs can possibly be used as a surrogate for skin DNA after dermal exposure to PAHs. 34 refs., 4 figs., 1 tab.

  19. CYCLOPENTA-FUSED POLYCYCLIC AROMATIC HYDROCARBONS IN STRAIN A/J MOUSE LUNG: DNA ADDUCTS, ONCOGENE MUTATIONS, & TUMORIGENESIS

    Science.gov (United States)

    Cyclopenta-fused Polycyclic Aromatic Hydrocarbons in Strain AJJ Mouse Lung: DNA Adducts, Oncogene Mutations, and Tumorigenesis. We have examined the relationships between DNA adducts, Ki-ras oncogene mutations, DNA adducts, and adenoma induction in the lungs of strain A/J...

  20. Abundance of DNA adducts of 4-oxo-2-alkenals, lipid peroxidation-derived highly reactive genotoxins.

    Science.gov (United States)

    Kawai, Yoshichika; Nuka, Erika

    2018-01-01

    Reactive oxygen species and their reaction products can damage DNA to form mutagenic lesions. Among the reactive species, lipid peroxidation-derived aldehydes react with nucleobases and form bulky exocyclic adducts. Many types of aldehyde-derived DNA adducts have been characterized, identified and detected in vitro and in vivo , whereas relative quantitative and pathophysiological contributions of each adduct still remain unclear. In recent years, an abundant class of DNA adducts derived from 4-oxo-2-alkenals have been identified, in addition to classic aldehyde-derived adducts. The presence of 4-oxo-2-alkenal-derived DNA adducts associated with age-related diseases has been revealed in rodents and humans. In vitro studies have demonstrated that 4-oxo-2-alkenals, as compared with other classes of lipid peroxidation-derived aldehydes, are highly reactive with nucleobases. It has been generally recognized that 4-oxo-2-alkenals are generated through oxidative degradation of the corresponding 4-hydroperoxy-2-alkenals, homolytic degradation products of polyunsaturated fatty acid hydroperoxides. Our recent results have also shown an alternative pathway for the formation of 4-oxo-2-alkenals, in which 2-alkenals could undergo the metal-catalyzed autoxidation resulting in the formation of the corresponding 4-oxo-2-alkenals. This review summarizes the basis of the formation of lipid peroxidation-derived genotoxic aldehydes and their covalent adduction to nucleobases, especially focusing on the abundance of 4-oxo-2-alkenal-derived DNA adducts.

  1. Smoking related carcinogen-DNA adducts in biopsy samples of human urinary bladder: Identification of N-(deoxyguanosin-8-yl)-4-aminobiphenyl as a major adduct

    Energy Technology Data Exchange (ETDEWEB)

    Talaska, G. (National Center for Toxicological Research, Jefferson, AR (United States) Univ. of Cincinnati, OH (United States)); Al-Juburi, A.Z.S.S. (John A. McClellan Memorial Veterans Administration Hospital, Little Rock, AR (United States)); Kadlubar, F.F. (National Center for Toxicological Research, Jefferson, AR (United States))

    1991-06-15

    The prevalence of covalent modifications to DNA (carcinogen-DNA adducts) in 42 human urinary bladder biopsy samples was investigated by {sup 32}P-postlabeling methods, with enhancement by both nuclease P1 treatment and 1-butanol extraction. Total mean carcinogen-DNA adduct levels and the mean levels of several specific adducts were significantly elevated in DNA samples of 13 current smokers, as opposed to 9 never smokers or 20 ex-smokers (5 years abstinence). There was no significant difference between the latter two groups. Several DNA adducts enhanced by nuclease P1 treatment were chromatographically similar to putative hydrocarbon DNA adducts reported earlier for placenta and lung DNA samples obtained from cigarette smokers. Putative aromatic amine adducts were detected by 1-butanol extraction that were not present when the samples were treated with nuclease P1. One of these displayed chromatographic behavior identical to the predominant adduct induced by the human urinary bladder carcinogen, 4-aminobiphenyl, which is present in cigarette smoke. This adduct comigrated in several thin-layer chromatographic systems with a synthetic N-(deoxyguanosin-8-yl)-4-amino(2,2{prime}-{sup 3}H)biphenyl-3{prime},5{prime}-bisphosphate marker. These data reinforce an association between cigarette smoking and DNA damage and suggest a molecular basis for the initiation of human urinary bladder cancer by cigarette smoke.

  2. Seasonal and intertidal impact on DNA adduct levels in gills of blue mussels (Mytilus edulis L.)

    Energy Technology Data Exchange (ETDEWEB)

    Skarpheoinsdottir, Halldora [Institute of Applied Environmental Research, Laboratory for Aquatic Ecotoxicology, Stockholm University, 106 91 Stockholm (Sweden)]. E-mail: halldora@itm.su.se; Ericson, Gunilla [Institute of Applied Environmental Research, Laboratory for Aquatic Ecotoxicology, Stockholm University, 106 91 Stockholm (Sweden); Halldorsson, Halldor P. [Institute of Biology, University of Iceland, Askja, Sturlugata 7, 101 Reykjavik (Iceland); University of Iceland, Sandgeroei Marine Centre, Garoevegur 1, 245 Sandgeroei (Iceland); Svavarsson, Joerundur [Institute of Biology, University of Iceland, Askja, Sturlugata 7, 101 Reykjavik (Iceland); University of Iceland, Sandgeroei Marine Centre, Garoevegur 1, 245 Sandgeroei (Iceland)

    2005-07-15

    The aim of this study was to elucidate possible seasonal variation in DNA adduct levels in blue mussels (Mytilus edulis), and to investigate the impact of intertidal exposure on the DNA adduct levels, i.e. to explore if DNA adduct levels in mussels in the intertidal zone differ from those in the subtidal zone. Blue mussels were deployed separately in the intertidal and subtidal zone at a contaminated and a reference site in Iceland, and sampled regularly during one year. Gill DNA adduct levels were found to be higher in mussels in the intertidal zone compared to the subtidal zone at the contaminated site, the difference being largest in winter. Total PAH tissue levels were also higher in mussels in the intertidal zone. Seasonal variation was observed in both DNA adduct and PAH tissue levels in mussels at the contaminated site, with lower levels from the time of transplantation in summer to autumn, maximum levels in winter, which decreased to lower levels again in spring and summer the following year. DNA adducts and PAH levels were low or below the detection limits in mussels at the reference site at all times, both in the intertidal and subtidal zone. - Gill DNA adduct and total PAH tissue levels were higher in mussels in the intertidal than subtidal zone, and higher in winter than summer.

  3. Effects of thiourea and ammonium bicarbonate on the formation and stability of bifunctional cisplatin-DNA adducts : consequences for the accurate quantification of adducts in (cellular) DNA

    NARCIS (Netherlands)

    Fichtinger-Schepman, A.M.J.; Dijk-Knijnenburg, H.C.M. van; Dijt, F.J.; Velde-Visser, S.D. van der; Berends, F.; Baan, R.A.

    1995-01-01

    Cisplatin reacts with DNA by forming mainly bifunctional adducts via reactive monofunctional intermediates. When freshly platinated DNA was postincubated with thiourea (10 mM, at 23 or 37°C) for periods of up to 24 h, followed by determination of mono- and diadducts, a rapid initial decrease was

  4. Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts

    DEFF Research Database (Denmark)

    Hemminki, K.; Zhang, L.F.; Krüger, J.

    1994-01-01

    Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between...

  5. Phosphoramide mustard exposure induces DNA adduct formation and the DNA damage repair response in rat ovarian granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, Shanthi, E-mail: shanthig@iastate.edu; Keating, Aileen F., E-mail: akeating@iastate.edu

    2015-02-01

    Phosphoramide mustard (PM), the ovotoxic metabolite of the anti-cancer agent cyclophosphamide (CPA), destroys rapidly dividing cells by forming NOR-G-OH, NOR-G and G-NOR-G adducts with DNA, potentially leading to DNA damage. A previous study demonstrated that PM induces ovarian DNA damage in rat ovaries. To investigate whether PM induces DNA adduct formation, DNA damage and induction of the DNA repair response, rat spontaneously immortalized granulosa cells (SIGCs) were treated with vehicle control (1% DMSO) or PM (3 or 6 μM) for 24 or 48 h. Cell viability was reduced (P < 0.05) after 48 h of exposure to 3 or 6 μM PM. The NOR-G-OH DNA adduct was detected after 24 h of 6 μM PM exposure, while the more cytotoxic G-NOR-G DNA adduct was formed after 48 h by exposure to both PM concentrations. Phosphorylated H2AX (γH2AX), a marker of DNA double stranded break occurrence, was also increased by PM exposure, coincident with DNA adduct formation. Additionally, induction of genes (Atm, Parp1, Prkdc, Xrcc6, and Brca1) and proteins (ATM, γH2AX, PARP-1, PRKDC, XRCC6, and BRCA1) involved in DNA repair were observed in both a time- and dose-dependent manner. These data support that PM induces DNA adduct formation in ovarian granulosa cells, induces DNA damage and elicits the ovarian DNA repair response. - Highlights: • PM forms ovarian DNA adducts. • DNA damage marker γH2AX increased by PM exposure. • PM induces ovarian DNA double strand break repair.

  6. Quantitative comparison between in vivo DNA adduct formation from exposure to selected DNA-reactive carcinogens, natural background levels of DNA adduct formation and tumour incidence in rodent bioassays.

    Science.gov (United States)

    Paini, Alicia; Scholz, Gabriele; Marin-Kuan, Maricel; Schilter, Benoît; O'Brien, John; van Bladeren, Peter J; Rietjens, Ivonne M C M

    2011-09-01

    This study aimed at quantitatively comparing the occurrence/formation of DNA adducts with the carcinogenicity induced by a selection of DNA-reactive genotoxic carcinogens. Contrary to previous efforts, we used a very uniform set of data, limited to in vivo rat liver studies in order to investigate whether a correlation can be obtained, using a benchmark dose (BMD) approach. Dose-response data on both carcinogenicity and in vivo DNA adduct formation were available for six compounds, i.e. 2-acetylaminofluorene, aflatoxin B1, methyleugenol, safrole, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline and tamoxifen. BMD(10) values for liver carcinogenicity were calculated using the US Environmental Protection Agency BMD software. DNA adduct levels at this dose were extrapolated assuming linearity of the DNA adduct dose response. In addition, the levels of DNA adducts at the BMD(10) were compared to available data on endogenous background DNA damage in the target organ. Although for an individual carcinogen the tumour response increases when adduct levels increase, our results demonstrate that when comparing different carcinogens, no quantitative correlation exists between the level of DNA adduct formation and carcinogenicity. These data confirm that the quantity of DNA adducts formed by a DNA-reactive compound is not a carcinogenicity predictor but that other factors such as type of adduct and mutagenic potential may be equally relevant. Moreover, comparison to background DNA damage supports the notion that the mere occurrence of DNA adducts above or below the level of endogenous DNA damage is neither correlated to development of cancer. These data strongly emphasise the need to apply the mode of action framework to understand the contribution of other biological effect markers playing a role in carcinogenicity.

  7. Sperm DNA adducts impair fertilization during ICSI but not during IVF.

    Directory of Open Access Journals (Sweden)

    Piotr Widłak

    2008-04-01

    Full Text Available Many studies emphasize the influence of the status of spermatozoal nucleus on fertilization, mainly with regard to DNA fragmentation. This study was undertaken to analyze the influence of DNA adducts content in spermatozoa on fertilization during assisted reproduction. Ovarian hyperstimulation, oocyte retrieval and laboratory work-up in 61 IVF (in vitro fertilization and 118 ICSI (intracytoplasmic sperm injection first cycles were performed according to the same protocol. Semen analysis was made according to WHO Manual (1999. DNA adducts assay in spermatozoa was performed by 32Ppostlabeling method. In total 331 fertilizable oocytes were obtained during IVF and 659 during ICSI. Both groups differed significantly by sperm count, motility and morphology but not by the concentration of DNA adducts in spermatozoa (0.0306 +/- 0.0217 in IVF versus 0.0373 +/- 0.0321 in ICSI. The fertilization rate during IVF was significantly influenced by sperm count (p=0.0002 and motility (p=0.0037 but not by DNA adducts concentration (p=0.30528, whereas during ICSI was positively influenced by sperm motility (p=0.04669 and negatively by DNA adducts concentration (p=0.00796. DNA adducts concentration in spermatozoa significantly negatively influences fertilization rate during ICSI, but not during IVF.

  8. Microdose-Induced Drug–DNA Adducts as Biomarkers of Chemotherapy Resistance in Humans and Mice

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Maike; Wang, Si-Si; Zhang, Hongyong; Lin, Tzu-yin; Malfatti, Michael; Haack, Kurt; Ognibene, Ted; Yang, Hongyuan; Airhart, Susan; Turteltaub, Kenneth W.; Cimino, George D.; Tepper, Clifford G.; Drakaki, Alexandra; Chamie, Karim; de Vere White, Ralph; Pan, Chong-xian; Henderson, Paul T.

    2016-11-30

    We report progress on predicting tumor response to platinum-based chemotherapy with a novel mass spectrometry approach. Fourteen bladder cancer patients were administered one diagnostic microdose each of [14C]carboplatin (1% of the therapeutic dose). Carboplatin–DNA adducts were quantified by accelerator mass spectrometry in blood and tumor samples collected within 24 hours, and compared with subsequent chemotherapy response. Patients with the highest adduct levels were responders, but not all responders had high adduct levels. Four patient-derived bladder cancer xenograft mouse models were used to test the possibility that another drug in the regimen could cause a response. The mice were dosed with [14C]carboplatin or [14C]gemcitabine and the resulting drug–DNA adduct levels were compared with tumor response to chemotherapy. At least one of the drugs had to induce high drug–DNA adduct levels or create a synergistic increase in overall adducts to prompt a corresponding therapeutic response, demonstrating proof-of-principle for drug–DNA adducts as predictive biomarkers.

  9. Smoking-related DNA adducts as potential diagnostic markers of lung cancer: new perspectives.

    Science.gov (United States)

    Grigoryeva, E S; Kokova, D A; Gratchev, A N; Cherdyntsev, E S; Buldakov, M A; Kzhyshkowska, J G; Cherdyntseva, N V

    2015-03-01

    In recent years, the new direction such as identification of informative circulating markers reflecting molecular genetic changes in the DNA of tumor cells was actively developed. Smoking-related DNA adducts are very promising research area, since they indicate high pathogenetic importance in the lung carcinogenesis and can be identified in biological samples with high accuracy and reliability using highly sensitive mass spectrometry methods (TOF/TOF, TOF/MS, MS/MS). The appearance of DNA adducts in blood or tissues is the result of the interaction of carcinogenic factors, such as tobacco constituents, and the body reaction which is determined by individual characteristics of metabolic and repair systems. So, DNA adducts may be considered as a cumulative mirror of heterogeneous response of different individuals to smoking carcinogens, which finally could determine the risk for lung cancer. This review is devoted to analysis of the role of DNA adducts in lung carcinogenesis in order to demonstrate their usefulness as cancer associated markers. Currently, there are some serious limitations impeding the widespread use of DNA adducts as cancer biomarkers, due to failure of standardization of mass spectrometry analysis in order to correctly measure the adduct level in each individual. However, it is known that all DNA adducts are immunogenic, their accumulation over some threshold concentration leads to the appearance of long-living autoantibodies. Thus, detection of an informative pattern of autoantibodies against DNA adducts using innovative multiplex ELISA immunoassay may be a promising approach to find lung cancer at an early stage in high-risk groups (smokers, manufacturing workers, urban dwellers).

  10. The use of an artificial nucleotide for polymerase-based recognition of carcinogenic O6-alkylguanine DNA adducts.

    Science.gov (United States)

    Wyss, Laura A; Nilforoushan, Arman; Williams, David M; Marx, Andreas; Sturla, Shana J

    2016-08-19

    Enzymatic approaches for locating alkylation adducts at single-base resolution in DNA could enable new technologies for understanding carcinogenesis and supporting personalized chemotherapy. Artificial nucleotides that specifically pair with alkylated bases offer a possible strategy for recognition and amplification of adducted DNA, and adduct-templated incorporation of an artificial nucleotide has been demonstrated for a model DNA adduct O(6)-benzylguanine by a DNA polymerase. In this study, DNA adducts of biological relevance, O(6)-methylguanine (O(6)-MeG) and O(6)-carboxymethylguanine (O(6)-CMG), were characterized to be effective templates for the incorporation of benzimidazole-derived 2'-deoxynucleoside-5'-O-triphosphates ( BENZI: TP and BIM: TP) by an engineered KlenTaq DNA polymerase. The enzyme catalyzed specific incorporation of the artificial nucleotide BENZI: opposite adducts, with up to 150-fold higher catalytic efficiency for O(6)-MeG over guanine in the template. Furthermore, addition of artificial nucleotide BENZI: was required for full-length DNA synthesis during bypass of O(6)-CMG. Selective incorporation of the artificial nucleotide opposite an O(6)-alkylguanine DNA adduct was verified using a novel 2',3'-dideoxy derivative of BENZI: TP. The strategy was used to recognize adducts in the presence of excess unmodified DNA. The specific processing of BENZI: TP opposite biologically relevant O(6)-alkylguanine adducts is characterized herein as a basis for potential future DNA adduct sequencing technologies. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Genetic modifiers of carcinogen DNA adducts in target lung and peripheral blood mononuclear cells.

    Science.gov (United States)

    Lee, Mi-Sun; Su, Li; Mark, Eugene J; Wain, John C; Christiani, David C

    2010-12-01

    Measurement of carcinogen DNA adducts in blood has been used as a surrogate for the target lung tissue. We aimed to examine whether genetic polymorphisms in several metabolic pathway genes modify the relation between DNA adducts in target lung and blood. One hundred and thirty-five early-stage lung cancer patients from the Massachusetts General Hospital were studied. DNA adducts were measured by the (32)P-postlabeling assay in lung and blood mononuclear cells (MNCs) in a subset of 53 who had paired blood samples. Single-nucleotide polymorphisms (SNPs) were assessed in genes involved in phase II (GSTs, NAT2, EPHX and NQO1), DNA repair (ERCC1, ERCC2 and XRCC1) and DNA methylation (MTHFR C677T and A1298C) pathways. There was a significant correlation between DNA adduct levels in lung and blood within the different genotypes, with one exception. Significant modifications in adducts were found by variants in genes for phase II metabolism [NAT2 (1.51 for rapid versus 0.76 for slow, P = 0.022)], DNA repair [ERCC1 C118T (P = 0.014), ERCC2 (P = 0.003) and XRCC1 (P = 0.025)] and MTHFR [C677T (P = 0.005) and A1298C (P = 0.005)]. The relation between DNA adducts in blood MNCs and target lung tissue was significantly modified by the single-nucleotide polymorphisms in the three main pathways. Despite the relatively small sample size, our results suggest that genetic factors may need to be considered when assessing the association of DNA adducts using surrogate tissue in studies of lung cancer. Further studies are needed to better understand their role and the mechanisms.

  12. Organocatalytic removal of formaldehyde adducts from RNA and DNA bases

    Science.gov (United States)

    Karmakar, Saswata; Harcourt, Emily M.; Hewings, David S.; Lovejoy, Alexander F.; Kurtz, David M.; Ehrenschwender, Thomas; Barandun, Luzi J.; Roost, Caroline; Alizadeh, Ash A.; Kool, Eric T.

    2015-09-01

    Formaldehyde is universally used to fix tissue specimens, where it forms hemiaminal and aminal adducts with biomolecules, hindering the ability to retrieve molecular information. Common methods for removing these adducts involve extended heating, which can cause extensive degradation of nucleic acids, particularly RNA. Here, we show that water-soluble bifunctional catalysts (anthranilates and phosphanilates) speed the reversal of formaldehyde adducts of mononucleotides over standard buffers. Studies with formaldehyde-treated RNA oligonucleotides show that the catalysts enhance adduct removal, restoring unmodified RNA at 37 °C even when extensively modified, while avoiding the high temperatures that promote RNA degradation. Experiments with formalin-fixed, paraffin-embedded cell samples show that the catalysis is compatible with common RNA extraction protocols, with detectable RNA yields increased by 1.5-2.4-fold using a catalyst under optimized conditions and by 7-25-fold compared with a commercial kit. Such catalytic strategies show promise for general use in reversing formaldehyde adducts in clinical specimens.

  13. Oral Cell DNA Adducts as Potential Biomarkers for Lung Cancer Susceptibility in Cigarette Smokers.

    Science.gov (United States)

    Hecht, Stephen S

    2017-01-17

    This perspective considers the use of oral cell DNA adducts, together with exposure and genetic information, to potentially identify those cigarette smokers at highest risk for lung cancer, so that appropriate preventive measures could be initiated at a relatively young age before too much damage has been done. There are now well established and validated analytical methods for the quantitation of urinary and serum metabolites of tobacco smoke toxicants and carcinogens. These metabolites provide a profile of exposure and in some cases lung cancer risk, but they do not yield information on the critical DNA damage parameter that leads to mutations in cancer growth control genes such as KRAS and TP53. Studies demonstrate a correlation between changes in the oral cavity and lung in cigarette smokers, due to the field effect of tobacco smoke. Oral cell DNA is readily obtained in contrast to DNA samples from the lung. Studies in which oral cell DNA and salivary DNA have been analyzed for specific DNA adducts are reviewed; some of the adducts identified have also been previously reported in lung DNA from smokers. The multiple challenges of developing a panel of oral cell DNA adducts that could be routinely quantified by mass spectrometry are discussed.

  14. Dehalogenation of Dichloromethane by Dichloromethane Dehalogenase/Glutathione S-Transferase Leads to Formation of DNA Adducts

    OpenAIRE

    Kayser, Martin F.; Vuilleumier, Stéphane

    2001-01-01

    Formation of DNA adducts following conversion of dichloromethane by bacterial dichloromethane dehalogenase/glutathione S-transferase was demonstrated. Adducts included dichloromethane carbon and glutathione sulfur atoms. A reaction with DNA occurred preferentially at guanine bases. Increased DNA degradation in a polA mutant of Methylobacterium dichloromethanicum DM4 grown with dichloromethane confirmed the genotoxicity associated with dichloromethane degradation, suggesting an important role ...

  15. Repair capacity for platinum-DNA adducts determines the severity of cisplatin-induced peripheral neuropathy.

    Science.gov (United States)

    Dzagnidze, Anna; Katsarava, Zaza; Makhalova, Julia; Liedert, Bernd; Yoon, Min-Suk; Kaube, Holger; Limmroth, Volker; Thomale, Juergen

    2007-08-29

    The pronounced neurotoxicity of the potent antitumor drug cisplatin frequently results in the onset of peripheral polyneuropathy (PNP), which is assumed to be initially triggered by platination products in the nuclear DNA of affected tissues. To further elucidate the molecular mechanisms, we analyzed in a mouse model the formation and processing of the main cisplatin-induced DNA adduct (guanine-guanine intrastrand cross-link) in distinct neuronal cell types by adduct-specific monoclonal antibodies. Comparison of the adduct kinetics in cisplatin-injected mice either proficient or deficient for nucleotide excision repair (NER) functions revealed the essential role of this DNA repair pathway in protecting differentiated cells of the nervous system from excessive formation of such lesions. Hence, chronic exposure to cisplatin resulted in an accelerated accumulation of unrepaired intrastrand cross-links in neuronal cells of mice with dysfunctional NER. The augmented adduct levels in dorsal root ganglion (DRG) cells of those animals coincided with an earlier onset of PNP-like functional disturbance of their sensory nervous system. Independently from the respective repair phenotype, the amount of persisting DNA cross-links in DRG neurons at a given cumulative dose was significantly correlated to the degree of sensory impairment as measured by electroneurography. Collectively, these findings suggest a new model for the processing of cisplatin adducts in primary neuronal cells and accentuate the crucial role of effectual DNA repair capacity in the target cells for the individual risk of therapy-induced PNP.

  16. MTHFR polymorphisms, folate intake and carcinogen DNA adducts in the lung.

    Science.gov (United States)

    Lee, Mi-Sun; Asomaning, Kofi; Su, Li; Wain, John C; Mark, Eugene J; Christiani, David C

    2012-09-01

    The methylenetetrahydrofolate reductase (MTHFR) genes and folate in one-carbon metabolism are essential for DNA methylation and synthesis. However, their role in carcinogen DNA damage in target lung tissue, a dosimeter for cancer risk, is not known. Our study aimed to investigate the association between genetic and nutritional one-carbon metabolism factors and DNA adducts in target lung. Data on 135 lung cancer cases from the Massachusetts General Hospital were studied. Genotyping was completed for MTHFR C677T (rs1801133) and A1298C (rs1801131). Information on dietary intake for one-carbon related micronutrients, folate and other B vitamin was derived from a validated food frequency questionnaire. DNA adducts in lung were measured by (32) P-postlabeling. After adjusting for potential confounders, DNA adduct levels in lung significantly increased by 69.2% [95% confidence interval (CI), 5.5% to 171.5%] for the MTHFR 1298AC+CC genotype. The high risk group, combining the A1298C (AC+CC) plus C677T (CT+TT) genotypes, had significantly enhanced levels of lung adducts by 210.7% (95% CI, 21.4% to 695.2%) in contrast to the A1298C (AA) plus C677T (CC) genotypes. Elevation of DNA adduct was pronounced-111.3% (95% CI, -3.0 to 360.5%) among 1298AC+CC patients, who consumed the lowest level of folate intake as compared to 1298AA individuals with highest tertile of intake. These results indicate that DNA adducts levels are influenced by MTHFR polymorphisms and low folate consumption, suggesting an important role of genetic and nutritional factors in protecting DNA damage from lung carcinogen in at-risk populations. Copyright © 2011 UICC.

  17. Formation of DNA adduct 8-hydroxy-2'-deoxyguanosine induced by man-made mineral fibres.

    Science.gov (United States)

    Leanderson, P; Söderkvist, P; Tagesson, C; Axelson, O

    1988-01-01

    Two man-made mineral fibres, rockwool and glasswool, were found to mediate hydroxylation of deoxyguanosine and calf thymus DNA to form the DNA adduct 8-hydroxy-2'-deoxyguanosine. The modification of the nucleoside is probably mediated by hydroxyl radicals and may play a role in fibre-induced carcinogenesis.

  18. Cisplatin-DNA adduct formation in rat spermatozoa and its effect on fetal development

    NARCIS (Netherlands)

    Hooser, S.T.; Dijk-Knijnenburg, C.M. van; Waalkens-Berendsen, I.D.H.; Smits-van Prooije, A.E.; Snoeij, N.J.; Baan, R.A.; Fichtinger-Schepman, M.J.

    2000-01-01

    Exposure of males to some genotoxic chemicals causes DNA damage in spermatozoa resulting in embryotoxicity and developmental defects in their offspring. This study demonstrates that cisplatin-DNA adducts could be measured in spermatozoa following treatment with the antineoplastic drug, cisplatin.

  19. Bulky DNA adducts in white blood cells: a pooled analysis of 3,600 subjects

    DEFF Research Database (Denmark)

    Ricceri, Fulvio; Godschalk, Roger W; Peluso, Marco

    2010-01-01

    Bulky DNA adducts are markers of exposure to genotoxic aromatic compounds, which reflect the ability of an individual to metabolically activate carcinogens and to repair DNA damage. Polycyclic aromatic hydrocarbons (PAHs) represent a major class of carcinogens that are capable of forming such add...

  20. PAH-DNA adducts in environmentally exposed population in relation to metabolic and DNA repair gene polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Binkova, Blanka [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Chvatalova, Irena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Lnenickova, Zdena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Milcova, Alena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Tulupova, Elena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester (United Kingdom); Farmer, Peter B. [Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester (United Kingdom); Sram, Radim J. [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic)]. E-mail: sram@biomed.cas.cz

    2007-07-01

    Epidemiologic studies indicate that prolonged exposure to particulate air pollution may be associated with increased risk of cardiovascular diseases and cancer in general population. These effects may be attributable to polycyclic aromatic hydrocarbons (PAHs) adsorbed to respirable air particles. It is expected that metabolic and DNA repair gene polymorphisms may modulate individual susceptibility to PAH exposure. This study investigates relationships between exposure to PAHs, polymorphisms of these genes and DNA adducts in group of occupationally exposed policemen (EXP, N = 53, males, aged 22-50 years) working outdoors in the downtown area of Prague and in matched 'unexposed' controls (CON, N = 52). Personal exposure to eight carcinogenic PAHs (c-PAHs) was evaluated by personal samplers during working shift prior to collection of biological samples. Bulky-aromatic DNA adducts were analyzed in lymphocytes by {sup 32}P-postlabeling assay. Polymorphisms of metabolizing (GSTM1, GSTP1, GSTT1, EPHX1, CYP1A1-MspI) and DNA repair (XRCC1, XPD) genes were determined by PCR-based RFLP assays. As potential modifiers and/or cofounders, urinary cotinine levels were analyzed by radioimmunoassay, plasma levels of vitamins A, C, E and folates by HPLC, cholesterol and triglycerides using commercial kits. During the sampling period ambient particulate air pollution was as follows: PM10 32-55 {mu}g/m{sup 3}, PM2.5 27-38 {mu}g/m{sup 3}, c-PAHs 18-22 ng/m{sup 3}; personal exposure to c-PAHs: 9.7 ng/m{sup 3} versus 5.8 ng/m{sup 3} (P < 0.01) for EXP and CON groups, respectively. The total DNA adduct levels did not significantly differ between EXP and CON groups (0.92 {+-} 0.28 adducts/10{sup 8} nucleotides versus 0.82 {+-} 0.23 adducts/10{sup 8} nucleotides, P = 0.065), whereas the level of the B[a]P-'like' adduct was significantly higher in exposed group (0.122 {+-} 0.036 adducts/10{sup 8} nucleotides versus 0.099 {+-} 0.035 adducts/10{sup 8} nucleotides, P = 0

  1. Formation, Repair, and Genotoxic Properties of Bulky DNA Adducts Formed from Tobacco-Specific Nitrosamines

    Directory of Open Access Journals (Sweden)

    Lisa A. Peterson

    2010-01-01

    Full Text Available 4-(Methylnitrosamino-1-(3-pyridyl-1-butanone (NNK and N′-nitrosonornicotine (NNN are tobacco-specific nitrosamines present in tobacco products and smoke. Both compounds are carcinogenic in laboratory animals, generating tumors at sites comparable to those observed in smokers. These Group 1 human carcinogens are metabolized to reactive intermediates that alkylate DNA. This paper focuses on the DNA pyridyloxobutylation pathway which is common to both compounds. This DNA route generates 7-[4-(3-pyridyl-4-oxobut-1-yl]-2′-deoxyguanosine, O2-[4-(3-pyridyl-4-oxobut-1-yl]-2′-deoxycytosine, O2-[4-(3-pyridyl-4-oxobut-1-yl]-2′-deoxythymidine, and O6-[4-(3-pyridyl-4-oxobut-1-yl]-2′-deoxyguanosine as well as unstable adducts which dealkylate to release 4-hydroxy-1-{3-pyridyl-1-butanone or depyriminidate/depurinate to generate abasic sites. There are multiple repair pathways responsible for protecting against the genotoxic effects of these adducts, including adduct reversal as well as base and nucleotide excision repair pathways. Data indicate that several DNA adducts contribute to the overall mutagenic properties of pyridyloxobutylating agents. Which adducts contribute to the carcinogenic properties of this pathway are likely to depend on the biochemistry of the target tissue.

  2. Potential use of DNA adducts to detect mutagenic compounds in soil

    Energy Technology Data Exchange (ETDEWEB)

    Hua Guoxiong [School of Biology, Institute for Research on the Environment and Sustainability, Devonshire Building, Newcastle University, NE1 7RU (United Kingdom)], E-mail: gh15@st-andrews.ac.uk; Lyons, Brett [CEFAS Weymouth Laboratory, Barrack Road, The Nothe, Weymouth, Dorset, DT4 8UB (United Kingdom); Killham, Ken [School of Biology, Cruickshank Building, University of Aberdeen, AB24 3UU (United Kingdom); Singleton, Ian [School of Biology, Institute for Research on the Environment and Sustainability, Devonshire Building, Newcastle University, NE1 7RU (United Kingdom)], E-mail: ian.singleton@ncl.ac.uk

    2009-03-15

    In this study, three different soils with contrasting features, spiked with 300 mg benzo[a]pyrene (BaP)/kg dry soil, were incubated at 20 deg. C and 60% water holding capacity for 540 days. At different time points, BaP and DNA were extracted and quantified, and DNA adducts were quantified by {sup 32}P-postlabelling. After 540 days incubation, 69.3, 81.6 and 83.2% of initial BaP added remained in Cruden Bay, Boyndie and Insch soils, respectively. Meanwhile, a significantly different amount of DNA-BaP adducts were found in the three soils exposed to BaP over time. The work demonstrates the concept that DNA adducts can be detected on DNA extracted from soil. Results suggest the technique is not able to directly reflect bioavailability of BaP transformation products. However, this new method provides a potential way to detect mutagenic compounds in contaminated soil and to assess the outcomes of soil remediation. - A novel DNA adduct assay may provide a potential technique to detect mutagenic compounds in contaminated soil.

  3. DNA Adducts from Anticancer Drugs as Candidate Predictive Markers for Precision Medicine.

    Science.gov (United States)

    Stornetta, Alessia; Zimmermann, Maike; Cimino, George D; Henderson, Paul T; Sturla, Shana J

    2017-01-17

    Biomarker-driven drug selection plays a central role in cancer drug discovery and development, and in diagnostic strategies to improve the use of traditional chemotherapeutic drugs. DNA-modifying anticancer drugs are still used as first line medication, but drawbacks such as resistance and side effects remain an issue. Monitoring the formation and level of DNA modifications induced by anticancer drugs is a potential strategy for stratifying patients and predicting drug efficacy. In this perspective, preclinical and clinical data concerning the relationship between drug-induced DNA adducts and biological response for platinum drugs and combination therapies, nitrogen mustards and half-mustards, hypoxia-activated drugs, reductase-activated drugs, and minor groove binding agents are presented and discussed. Aspects including measurement strategies, identification of adducts, and biological factors that influence the predictive relationship between DNA modification and biological response are addressed. A positive correlation between DNA adduct levels and response was observed for the majority of the studies, demonstrating the high potential of using DNA adducts from anticancer drugs as mechanism-based biomarkers of susceptibility, especially as bioanalysis approaches with higher sensitivity and throughput emerge.

  4. Environmental air pollution and DNA adducts in Copenhagen bus drivers - effect of GSTM1 and NAT2 genotypes on adduct level

    DEFF Research Database (Denmark)

    Nielsen, Per Sabro; de Pater, Nettie; Okkels, Henrik

    1996-01-01

    rural controls (0.074 fmol/microg DNA, n = 60, P metabolizing enzymes, GSTM1 and NAT2, on adduct levels was investigated. No statistically significant effects...... to levels of exposure to urban air pollution and indicated that these adducts might be helpful as a means of classifying better different exposure groups for epidemiological studies. Furthermore, it demonstrated the ability of 32P-postlabelling to discern small differences in low exposure to ambient air...

  5. Base-Displaced Intercalated Structure of the N-(2'-Deoxyguanosin-8-yl)-3-aminobenzanthrone DNA Adduct.

    Science.gov (United States)

    Politica, Dustin A; Malik, Chanchal K; Basu, Ashis K; Stone, Michael P

    2015-12-21

    3-Nitrobenzanthrone (3-NBA), an environmental mutagen found in diesel exhaust and a suspected carcinogen, undergoes metabolic reduction followed by reaction with DNA to form aminobenzanthrone (ABA) adducts, with the major alkylation product being N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (C8-dG-ABA). Site-specific synthesis of the C8-dG-ABA adduct in the oligodeoxynucleotide 5'-d(GTGCXTGTTTGT)-3':5'-d(ACAAACACGCAC)-3'; X = C8-dG-ABA adduct, including codons 272-275 of the p53 gene, has allowed for investigation into the structural and thermodynamic properties of this adduct. The conformation of the C8-dG-ABA adduct was determined using NMR spectroscopy and was refined using molecular dynamics (MD) calculations restrained by experimentally determined interproton distance restraints obtained from NOE experiments. The refined structure revealed that the C8-dG-ABA adduct formed a base-displaced intercalated conformation. The adducted guanine was shifted into the syn conformation about the glycosidic bond. The 5'- and 3'-neighboring base pairs remained intact. While this facilitated π-stacking interactions between the ABA moiety and neighboring bases, the thermal melting temperature (Tm) of the adduct-containing duplex showed a decrease of 11 °C as compared to the corresponding unmodified oligodeoxynucleotide duplex. Overall, in this sequence, the base-displaced intercalated conformation of the C8-dG-ABA lesion bears similarity to structures of other arylamine C8-dG adducts. However, in this sequence, the base-displaced intercalated conformation for the C8-dG-ABA adduct differs from the conformation of the N(2)-dG-ABA adduct reported by de los Santos and co-workers, in which it is oriented in the minor groove toward the 5' end of the duplex, with the modified guanine remaining in the anti conformation about the glyosidic torsion angle, and the complementary base remaining within the duplex. The results are discussed in relationship to differences between the C8-d

  6. Dehalogenation of Dichloromethane by Dichloromethane Dehalogenase/Glutathione S-Transferase Leads to Formation of DNA Adducts

    Science.gov (United States)

    Kayser, Martin F.; Vuilleumier, Stéphane

    2001-01-01

    Formation of DNA adducts following conversion of dichloromethane by bacterial dichloromethane dehalogenase/glutathione S-transferase was demonstrated. Adducts included dichloromethane carbon and glutathione sulfur atoms. A reaction with DNA occurred preferentially at guanine bases. Increased DNA degradation in a polA mutant of Methylobacterium dichloromethanicum DM4 grown with dichloromethane confirmed the genotoxicity associated with dichloromethane degradation, suggesting an important role of DNA repair in the metabolism of halogenated, DNA-alkylating compounds by bacteria. PMID:11489877

  7. Use of LC-MS/MS and Stable Isotopes to Differentiate Hydroxymethyl and Methyl DNA Adducts from Formaldehyde and Nitrosodimethylamine

    Science.gov (United States)

    Lu, Kun; Craft, Sessaly; Nakamura, Jun; Moeller, Benjamin C.; Swenberg, James A.

    2012-01-01

    Formaldehyde is a known human and animal carcinogen that forms DNA adducts, and causes mutations. While there is widespread exposure to formaldehyde in the environment, formaldehyde is also an essential biochemical in all living cells. The presence of both endogenous and exogenous sources of formaldehyde makes it difficult to develop exposure-specific DNA biomarkers. Furthermore, chemicals such as nitrosodimethylamine form one mole of formaldehyde for every mole of methylating agent, raising questions about potential co-carcinogenesis. Formaldehyde-induced hydroxymethyl DNA adducts are not stable and need to be reduced to stable methyl adducts for detection, which adds another layer of complexity to identifying the origins of these adducts. In this study, highly sensitive mass spectrometry methods and isotope labeled compounds were used to differentiate between endogenous and exogenous hydroxymethyl and methyl DNA adducts. We demonstrate that N2-hydroxymethyl-dG is the primary DNA adduct formed in cells following formaldehyde exposure. In addition, we show that alkylating agents induce methyl adducts at N2-dG and N6-dA positions, which are identical to the reduced forms of hydroxymethyl adducts arising from formaldehyde. The use of highly sensitive LC-MS/MS and isotope labeled compounds for exposure solves these challenges and provides mechanistic insights on the formation and role of these DNA adducts. PMID:22148432

  8. Formation of Hydroxymethyl DNA Adducts in Rats Orally Exposed to Stable Isotope Labeled Methanol

    Science.gov (United States)

    Lu, Kun; Gul, Husamettin; Upton, Patricia B.; Moeller, Benjamin C.; Swenberg, James A.

    2012-01-01

    Methanol is a large volume industrial chemical and widely used solvent and fuel additive. Methanol’s well known toxicity and use in a wide spectrum of applications has raised long-standing environmental issues over its safety, including its carcinogenicity. Methanol has not been listed as a carcinogen by any regulatory agency; however, there are debates about its carcinogenic potential. Formaldehyde, a metabolite of methanol, has been proposed to be responsible for the carcinogenesis of methanol. Formaldehyde is a known carcinogen and actively targets DNA and protein, causing diverse DNA and protein damage. However, formaldehyde-induced DNA adducts arising from the metabolism of methanol have not been reported previously, largely due to the absence of suitable DNA biomarkers and the inability to differentiate what was due to methanol compared with the substantial background of endogenous formaldehyde. Recently, we developed a unique approach combining highly sensitive liquid chromatography-mass spectrometry methods and exposure to stable isotope labeled chemicals to simultaneously quantify formaldehyde-specific endogenous and exogenous DNA adducts. In this study, rats were exposed daily to 500 or 2000 mg/kg [13CD4]-methanol by gavage for 5 days. Our data demonstrate that labeled formaldehyde arising from [13CD4]-methanol induced hydroxymethyl DNA adducts in multiple tissues in a dose-dependent manner. The results also demonstrated that the number of exogenous DNA adducts was lower than the number of endogenous hydroxymethyl DNA adducts in all tissues of rats administered 500 mg/kg per day for 5 days, a lethal dose to humans, even after incorporating an average factor of 4 for reduced metabolism due to isotope effects of deuterium-labeled methanol into account. PMID:22157354

  9. MTHFR Polymorphisms, Folate Intake, and Carcinogen DNA Adducts in the Lung

    OpenAIRE

    Lee, Mi-Sun; Asomaning, Kofi; Su, Li; Wain, John C.; Mark, Eugene J.; Christiani, David C.

    2012-01-01

    The methylenetetrahydrofolate reductase (MTHFR) genes and folate in one-carbon metabolism are essential for DNA methylation and synthesis. However, their role in carcinogen DNA damage in target lung tissue, a dosimeter for cancer risk, is not known. Our study aimed to investigate the association between genetic and nutritional one-carbon metabolism factors and DNA adducts in target lung. Data on 135 lung cancer cases from the Massachusetts General Hospital were studied. Genotyping was complet...

  10. Cigarette Smoking, BPDE-DNA Adducts, and Aberrant Promoter Methylations of Tumor Suppressor Genes (TSGs) in NSCLC from Chinese Population.

    Science.gov (United States)

    Jin, Yongtang; Xu, Peiwei; Liu, Xinneng; Zhang, Chunye; Tan, Cong; Chen, Chunmei; Sun, Xiaoyu; Xu, Yingchun

    2016-01-01

    Non-small cell lung cancer (NSCLC) is related to the genetic and epigenetic factors. The goal of this study was to determine association of cigarette smoking and BPDE-DNA adducts with promoter methylations of several genes in NSCLC. Methylation of the promoters of p16, RARβ, DAPK, MGMT, and TIMP-3 genes of tumor tissues from 199 lung cancer patients was analyzed with methylation-specific PCR (MSP), and BPDE-DNA adduct level in lung cancer tissue was obtained by ELISA. Level of BPDE-DNA adduct increased significantly in males, aged people (over 60 years), and smokers; however, no significant difference was found while comparing the BPDE-DNA adduct levels among different tumor types, locations, and stages. Cigarette smoking was also associated with increased BPDE-DNA adducts level (OR = 2.43, p > .05) and increased methylation level in at least 1 gene (OR = 5.22, p smoking also significantly increase the risk of p16 or DAPK methylation (OR = 3.02, p smoking for more than 40 pack-years (OR = 4.21, p smoking is significantly associated with the increase of BPDE-DNA adduct level, promoter hypermethylation of p16 and DAPK genes, while BPDE-DNA adduct was not significantly related to abnormal promoter hypermethylation in TSGs, suggesting that BPDE-DNA adducts and TSGs methylations play independent roles in NSCLC.

  11. Comprehensive DNA Adduct Analysis Reveals Pulmonary Inflammatory Response Contributes to Genotoxic Action of Magnetite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Kousuke Ishino

    2015-02-01

    Full Text Available Nanosized-magnetite (MGT is widely utilized in medicinal and industrial fields; however, its toxicological properties are not well documented. In our previous report, MGT showed genotoxicity in both in vitro and in vivo assay systems, and it was suggested that inflammatory responses exist behind the genotoxicity. To further clarify mechanisms underlying the genotoxicity, a comprehensive DNA adduct (DNA adductome analysis was conducted using DNA samples derived from the lungs of mice exposed to MGT. In total, 30 and 42 types of DNA adducts were detected in the vehicle control and MGT-treated groups, respectively. Principal component analysis (PCA against a subset of DNA adducts was applied and several adducts, which are deduced to be formed by inflammation or oxidative stress, as the case of etheno-deoxycytidine (εdC, revealed higher contributions to MGT exposure. By quantitative-LC-MS/MS analysis, εdC levels were significantly higher in MGT-treated mice than those of the vehicle control. Taken together with our previous data, it is suggested that inflammatory responses might be involved in the genotoxicity induced by MGT in the lungs of mice.

  12. Cisplatin intrastrand adducts sensitize DNA to base damage by hydrated electrons.

    Science.gov (United States)

    Behmand, B; Wagner, J R; Sanche, L; Hunting, D J

    2014-05-08

    The oligonucleotide TTTTTGTGTTT with or without a cisplatin adduct was reacted with hydrated electrons generated by ionizing radiation. Hydroxyl radicals were quenched with ethylenediaminetetraacetic acid (EDTA), and the solutions were bubbled with wet nitrogen to eliminate oxygen, a scavenger of hydrated electrons. Prior to irradiation, the structure of the initial cisplatin adduct was identified by mass spectrometry as G-cisplatin-G. Radiation damage to DNA bases was quantified by high-performance liquid chromatography (HPLC), after enzymatic digestion of the TTTTTGTGTTT-cisplatin complex to deoxyribonucleosides. The masses of the platinum adducts following digestion and separation by HPLC were measured by mass spectrometry. Our results demonstrate that hydrated electrons induce damage to thymines as well as detachment of the cisplatin moiety from both guanines in the oligonucleotide. This detachment regenerates both unmodified guanine and damaged guanine, in equimolar amounts. At 1000 Gy, a net average of 2.5 thymines and 1 guanine are damaged for each platinum lost from the oligonucleotide. Given the extensive base damage that occurs for each cisplatin adduct lost, it is clear that, prior to undergoing detachment, these adducts must catalyze several cycles of reactions of hydrated electrons with DNA bases. It is likely that a single reaction leads to the loss of the cisplatin adduct and the damage observed on the guanine base; however, the damage to the thymine bases must require the continued presence of the cisplatin adduct, acting as a catalyst. To our knowledge, this is the first time that platinum-DNA adducts have been shown to have catalytic activity. We propose two pathways for the interaction of hydrated electrons with TTTTTGTGTTT-cisplatin: (1) the hydrated electron is initially captured by a thymine base and transferred by base to base electron hopping to the guanine site, where the cisplatin moiety detaches from the oligonucleotide via dissociative

  13. Role of CYP1B1 in PAH-DNA adduct formation and breast cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Goth-Goldstein, Regine; Russell, Marion L.; Muller, A.P.; Caleffi, M.; Eschiletti, J.; Graudenz, M.; Sohn, Michael D.

    2010-04-01

    This study investigated the hypothesis that increased exposure to polycyclic aromatic hydrocarbons (PAHs) increases breast cancer risk. PAHs are products of incomplete burning of organic matter and are present in cigarette smoke, ambient air, drinking water, and diet. PAHs require metabolic transformation to bind to DNA, causing DNA adducts, which can lead to mutations and are thought to be an important pre-cancer marker. In breast tissue, PAHs appear to be metabolized to their cancer-causing form primarily by the cytochrome P450 enzyme CYP1B1. Because the genotoxic impact of PAH depends on their metabolism, we hypothesized that high CYP1B1 enzyme levels result in increased formation of PAH-DNA adducts in breast tissue, leading to increased development of breast cancer. We have investigated molecular mechanisms of the relationship between PAH exposure, CYP1B1 expression and breast cancer risk in a clinic-based case-control study. We collected histologically normal breast tissue from 56 women (43 cases and 13 controls) undergoing breast surgery and analyzed these specimens for CYP1B1 genotype, PAH-DNA adducts and CYP1B1 gene expression. We did not detect any difference in aromatic DNA adduct levels of cases and controls, only between smokers and non-smokers. CYP1B1 transcript levels were slightly lower in controls than cases, but the difference was not statistically significant. We found no correlation between the levels of CYP1B1 expression and DNA adducts. If CYP1B1 has any role in breast cancer etiology it might be through its metabolism of estrogen rather than its metabolism of PAHs. However, due to the lack of statistical power these results should be interpreted with caution.

  14. Role of CYP1B1 in PAH-DNA Adduct Formation and Breast Cancer Risk

    National Research Council Canada - National Science Library

    Goth-Goldstein, Regine

    2002-01-01

    ...) to reactive intermediates appears to be the cytochrome P45O enzyme CYPlB1. High CYPlB1 enzyme levels may result in increased formation of PAH-DNA adducts in breast tissue and lead to subsequent development of breast cancer...

  15. Quantification of acylfulvene- and illudin S-DNA adducts in cells with variable bioactivation capacities.

    Science.gov (United States)

    Pietsch, Kathryn E; van Midwoud, Paul M; Villalta, Peter W; Sturla, Shana J

    2013-01-18

    Illudin S and its semisynthetic analogue acylfulvene (AF) are structurally similar but elicit different biological responses. AF is a bioreductive alkylating anticancer agent with a favorable therapeutic index, while illudin S is in general highly toxic. AF toxicity is dependent on the reductase enzyme prostaglandin reductase 1 (PTGR1) for activation to a cytotoxic reactive intermediate. While illudin S can be metabolized by PTGR1, available data suggest that its toxicity does not correspond with PTGR1 function. The goal of this study was to understand how drug cytotoxicity relates to cellular bioactivation capacity and the identity and quantity of AF- or illudin S-DNA adducts. The strategy involved identification of novel illudin S-DNA adducts and their quantitation in a newly engineered SW-480 colon cancer cell line that stably overexpresses PTGR1 (PTGR1-480). These data were compared with cytotoxicity data for both compounds in PTGR1-480 versus normal SW-480 cells, demonstrating that AF forms more DNA adducts and is more cytotoxic in cells with higher levels of PTGR1, whereas illudin S cytotoxicity and adduct formation are not influenced by PTGR1 levels. Results are discussed in the context of an overall model for how changes in relative propensities of these compounds to undergo cellular processes, such as bioactivation, contributes to DNA damage, and cytotoxicity.

  16. DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles

    Science.gov (United States)

    AbstractContext: Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts. Objectives: We compared the formation of covalent DNA adducts by the in vitro metabol...

  17. Development and validation of a direct sandwich chemiluminescence immunoassay for measuring DNA adducts of benzo[a]pyrene and other polycyclic aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Georgiadis, Panagiotis; Kovács, Katalin; Kaila, Stella

    2012-01-01

    We have developed and validated a sandwich chemiluminescence immunoassay (SCIA) which measures polycyclic aromatic hydrocarbon (PAH)-DNA adducts combining high throughput and adequate sensitivity, appropriate for evaluation of adduct levels in human population studies. Fragmented DNA is incubated...... lower (30-60%) than levels of bulky DNA adducts measured in the same samples by (32)P-postlabelling. The BPDE-DNA SCIA also detected adducts produced in vivo by PAHs other than BP. When blood DNA samples from maternal/infant pairs were assayed by BPDE-DNA SCIA, the adduct levels obtained were...

  18. Characterization of adducts formed in reactions of acrolein with thymidine and calf thymus DNA.

    Science.gov (United States)

    Pawłowicz, Agnieszka J; Kronberg, Leif

    2008-01-01

    Acrolein, an important industrial chemical and environmental contaminant, has been shown to interact with nucleic acids in vitro and in vivo. In this study, we examined the reactivity of acrolein towards thymidine and calf-thymus double- and single-stranded DNA in aqueous buffered solutions. LC-MS Analyses of the reaction mixture of acrolein with thymidine showed the formation of five structurally different adducts. The structures of the products were determined on the basis of mass spectrometry, UV absorbance, and (1)H- and (13)C-NMR spectroscopy. The adducts were identified as 3-(3-oxopropyl)thymidine (dT1), 3-[(tetrahydro-2,4-dihydroxypyran-3-yl)methyl]thymidine (dT2), 2-(hydroxymethyl)-5-(thymidin-3-yl)pent-2-enal (dT3), 3-hydroxy-2-methylidene-5-(thymidin-3-yl)pentanal (dT4), and 2-[(thymidin-3-yl)methyl]penta-2,4-dienal (dT5). The adducts dT2-dT5 were formed in reaction of dT1 with acrolein. In the reaction of acrolein with calf-thymus DNA, dT1 was the only adduct detected in the DNA hydrolysate.

  19. Enhanced activity of punicalagin delivered via polymeric implants against benzo[a]pyrene-induced DNA adducts.

    Science.gov (United States)

    Aqil, Farrukh; Vadhanam, Manicka V; Gupta, Ramesh C

    2012-03-18

    We investigated the effect of punicalagin (PC) on benzo[a]pyrene (BP)-induced DNA adducts in vitro and in vivo. Incubation of BP (1 μM) with rat liver microsomes, appropriate co-factors and DNA in the presence of vehicle or punicalagin (1-40 μM) showed dose-dependent inhibition of the resultant DNA adducts, with essentially complete (97%) inhibition at 40 μM. However, PC failed to inhibit anti-BPDE-induced DNA adducts when tested in an in vitro non-microsomal system, suggesting that the inhibition of the microsomal BP-DNA adducts occurred due to inhibition of P450 1A1 by PC. To determine its efficacy in vivo, female S/D rats were administered punicalagin via the diet (1500 ppm; approximately 19 mg/day/animal) or subcutaneous polymeric implants (two 2-cm, 200mg with 20% drug load; 40 mg PC/implant) and then treated with continuous low-dose of BP by a subcutaneous polymeric implant (2 cm, 200mg with 10% load; 20mg BP/implant) and euthanized after 10 days. Analysis of the lung DNA by (32)P-postlabeling showed significant (60%; p=0.029) inhibition of DNA adducts by PC administered via the implants; the dietary route showed modest (34%) but statistically insignificant inhibition. Furthermore, total PC administered by implants was approximately 38-fold lower compared with the dietary route. Analysis of the lung microsomes showed significant inhibition of cytochrome P450 1A1 activity and induction of glutathione. Release of PC from the implants was found to be biphasic starting with a burst release, followed by a gradual decline. Ultra performance liquid chromatography analysis showed no detectable PC in the plasma but its hydrolyzed product, ellagic acid was readily detected. The plasma concentration of ellagic acid was over two orders of magnitude higher (589 ± 78 ng/mL) in the implant group compared with diet (4.36 ± 0.83 ng/mL). Together, our data show that delivery of PC by implants can reduce its effective dose substantially, and that the inhibition of DNA

  20. Comparison of immunoaffinity chromatography enrichment and nuclease P1 procedures for 32P-postlabelling analysis of PAH- DNA adducts

    NARCIS (Netherlands)

    Randerath, K.; Sriram, P.; Moorthy, B.; Aston, J.P.; Baan, R.A.; Berg, P.T.M. van den; Booth, E.D.; Watson, W.P.

    1998-01-01

    32P-postlabelling analysis for detecting DNA adducts formed by polycyclic aromatic compounds is one of the most widely used techniques for assessing genotoxicity associated with these compounds. In cases where the formation of adducts is extremely low, a crucial step in the analysis is an enrichment

  1. Biomarkers for exposure to ambient air pollution - Comparison of carcinogen-DNA adduct levels with other exposure markers and markers for oxidative stress

    DEFF Research Database (Denmark)

    Autrup, Herman; Daneshvar, Bahram; Dragsted, Lars Ove

    1999-01-01

    Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts...... correlations were observed between bulky carcinogen-DNA adduct and PAM-albumin levels (p = 0.005), and between DNA adduct and gamma-glutamyl semialdehyde (GGS) in hemoglobin (p = 0.11). Highly significant correlations were found between PAM-albumin adducts and AAS in plasma (r = 0.001) and GGS in hemoglobin (p...... in the combined group. A significant negative correlation was only observed between bulky carcinogen-DNA adducts and PAM-albumin adducts (p = 0.02) and between DNA adduct and urinary mutagenic activity (p = 0.02) in the GSTM1 null group, bur not in the workers who were homozygotes or heterozygotes for GSTM1. Our...

  2. Biomarkers for Exposure to Ambient Air Pollution - Comparison of Carcinogen-DNA Adduct Levels with Other Exposure Markers and Markers for Oxidative Stress

    DEFF Research Database (Denmark)

    Autrup, Herman; Daneshvar, Bahram; Dragsted, Lars Ove

    1999-01-01

    Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts...... correlations were observed between bulky carcinogen-DNA adduct and PAH-albumin levels (p = 0.005), and between DNA adduct and [gamma]-glutamyl semialdehyde (GGS) in hemoglobin (p = 0.11). Highly significant correlations were found between PAH-albumin adducts and AAS in plasma (p = 0.001) and GGS in hemoglobin...... in the combined group. A significant negative correlation was only observed between bulky carcinogen-DNA adducts and PAH-albumin adducts (p = 0.02) and between DNA adduct and urinary mutagenic activity (p = 0.02) in the GSTM1 null group, but not in the workers who were homozygotes or heterozygotes for GSTM1. Our...

  3. Comparative synchronous fluorescence spectrophotometry and 32P-postlabeling analysis of PAH-DNA adducts in human lung and the relationship to TP53 mutations

    DEFF Research Database (Denmark)

    Andreassen, Åshild; Kure, Elin H.; Nielsen, Per Sabro

    1996-01-01

    Polycyclic aromatic hydrocarbon (PAH)-DNA adducts were studied in human lung from 39 lung cancer patients by synchronous fluorescence spectrophotometric (SFS) and 32P-postlabeling assays. Regression analysis of the samples failed to detect any correlation between benzo[a]pyrene-diolepoxide (BPDE......)-DNA adducts detected by SFS and the BPDE co-migrating spot detected by 32P-postlabeling. We have also analyzed the relationship between adduct levels and TP53 mutations. By postlabeling diagonal radioactive zone (DRZ) adducts were detected in 37 of 39 (95%) lung tissues from lung cancer patients...... and the adduct level ranged from 6.81 to 108.50 adducts/10(8) nucleotide. Thirty-three of 39 (85%) had detectable levels of BPDE-DNA adducts (> 1 adduct/10(9) nucleotide). Current heavy smokers (> 20 cigarettes/day) have significantly higher DRZ adduct levels compared to individuals smoking less than 20...

  4. Polycyclic aromatic hydrocarbon--DNA adducts in white blood cells from lung cancer patients: no correlation with adduct levels in lung

    NARCIS (Netherlands)

    van Schooten, F. J.; Hillebrand, M. J.; van Leeuwen, F. E.; van Zandwijk, N.; Jansen, H. M.; den Engelse, L.; Kriek, E.

    1992-01-01

    Smokers of cigarettes are exposed to a number of carcinogens, including polycyclic aromatic hydrocarbons (PAHs), and are at a high risk for lung cancer. PAHs exert their carcinogenic activity after metabolic activation to reactive intermediates that can damage DNA through adduct formation. Measuring

  5. Lifestyle, Environmental, and Genetic Predictors of Bulky DNA Adducts in a Study Population Nested within a Prospective Danish Cohort

    DEFF Research Database (Denmark)

    Eriksen, K. T.; Sørensen, M.; Autrup, H.

    2010-01-01

    Bulky DNA adducts are considered a potential biomarker of cancer risk. In this study, the association between various lifestyle, environmental, and genetic factors and the levels of bulky DNA adducts in peripheral leukocytes was examined in a study group nested within a population-based prospective...... Danish cohort. At enrollment, blood samples were collected and information on lifestyle, including dietary and smoking habits, obtained. Previously, bulky DNA adducts were measured in 245 individuals who developed lung cancer and 255 control members of the cohort. Of these 500 individuals, data on 375...... individuals were included in this study, excluding 125 cases, which developed lung cancer within the first 3 yr after blood sampling. Bulky DNA adduct levels were measured by 32P-postlabeling technique and polymorphisms in carcinogen metabolism and DNA repair genes were determined. Potential predictors...

  6. Bypass of Aflatoxin B[subscript 1] Adducts by the Sulfolobus solfataricus DNA Polymerase IV

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Surajit; Brown, Kyle L.; Egli, Martin; Stone, Michael P. (Vanderbilt)

    2012-07-18

    Aflatoxin B{sub 1} (AFB{sub 1}) is oxidized to an epoxide in vivo, which forms an N7-dG DNA adduct (AFB{sub 1}-N7-dG). The AFB{sub 1}-N7-dG can rearrange to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative. Both AFB{sub 1}-N7-dG and the {beta}-anomer of the AFB{sub 1}-FAPY adduct yield G {yields} T transversions in Escherichia coli, but the latter is more mutagenic. We show that the Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) bypasses AFB{sub 1}-N7-dG in an error-free manner but conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including misinsertion of dATP, consistent with the G {yields} T mutations observed in E. coli. Three ternary (Dpo4-DNA-dNTP) structures with AFB{sub 1}-N7-dG adducted template:primers have been solved. These demonstrate insertion of dCTP opposite the AFB{sub 1}-N7-dG adduct, and correct vs incorrect insertion of dATP vs dTTP opposite the 5'-template neighbor dT from a primed AFB{sub 1}-N7-dG:dC pair. The insertion of dTTP reveals hydrogen bonding between the template N3 imino proton and the O{sup 2} oxygen of dTTP, and between the template T O{sup 4} oxygen and the N3 imino proton of dTTP, perhaps explaining why this polymerase does not efficiently catalyze phosphodiester bond formation from this mispair. The AFB{sub 1}-N7-dG maintains the 5'-intercalation of the AFB{sub 1} moiety observed in DNA. The bond between N7-dG and C8 of the AFB{sub 1} moiety remains in plane with the alkylated guanine, creating a 16{sup o} inclination of the AFB{sub 1} moiety with respect to the guanine. A binary (Dpo4-DNA) structure with an AFB{sub 1}-FAPY adducted template:primer also maintains 5'-intercalation of the AFB{sub 1} moiety. The {beta}-deoxyribose anomer is observed. Rotation about the FAPY C5-N{sup 5} bond orients the bond between N{sup 5} and C8 of the AFB{sub 1} moiety out of plane in the 5'-direction, with respect to the FAPY base. The formamide group extends in the 3'-direction. This improves

  7. Modified immunoslotblot assay to detect hemi and sulfur mustard DNA adducts.

    Science.gov (United States)

    Kehe, Kai; Schrettl, Verena; Thiermann, Horst; Steinritz, Dirk

    2013-12-05

    Sulfur mustard (SM) is an old chemical warfare agent causing blisters (vesicant). Skin toxicity is thought to be partly caused by SM induced DNA damage. SM and the hemi mustard 2-chloroethyl ethyl sulfide (CEES) are bi- and monofunctional DNA alkylating agents, respectively. Both chemicals react especially with N7 guanine. The most abundant adducts are 7-hydroxyethylthioethylguanine for SM (61%) and 7-ethyl thioethylguanine for CEES. Thus, DNA alkylation should serve as a biomarker of SM exposure. A specific monoclonal antibody (2F8) was previously developed to detect SM and CEES adducts at N7 position by means of immunoslotblot (ISB) technique (van der Schans et al. (2004) [16]). Nitrogen mustards (HN-1, HN-2, HN-3) are alkylating agents with structural similarities, which can form DNA adducts with N7 guanine. The aim of the presented work was to modify the van der Schans protocol for use in a field laboratory and to test the cross reactivity of the 2F8 antibody against nitrogen mustards. Briefly, human keratinocytes were exposed to SM and CEES (0-300μM, 60min) or HN-1, HN-2, HN-3 (120min). After exposure, cells were scraped and DNA was isolated and normalized. 1μg DNA was transferred to a nitrocellulose membrane using a slotblot technique. After incubation with 2F8 antibody, the DNA adducts were visualized with chromogen staining (3,3'-diaminobenzidine (DAB), SeramunGrün). Blots were photographed and signal intensity was quantified. In general, DAB was superior to SeramunGrün stain. A staining was seen from 30nM to 300μM of SM or CEES, respectively. However, statistically significant DNA adducts were detected after CEES and SM exposure above 30μM which is below the vesicant threshold. No signal was observed after HN-1, HN-2, HN-3 exposure. The total hands-on time to complete the assay was about 36h. Further studies are necessary to validate SM or CEES exposure in blister roofs of exposed patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. ERCC1 and ERCC2 haplotype modulates induced BPDE-DNA adducts in primary cultured lymphocytes.

    Directory of Open Access Journals (Sweden)

    Xiaobo Lu

    Full Text Available BACKGROUND: Benzo[a]pyrene(B[a]P, and its ultimate metabolite Benzo[a]pyrene 7,8-diol 9,10-epoxide (BPDE, are classic DNA damaging carcinogens. DNA damage caused by BPDE is normally repaired by Nucleotide Excision Repair (NER, of which ERCC1 and ERCC2/XPD exert an indispensable role. Genetic variations in ERCC1 and ERCC2 have been related to DNA repair efficiency. In this study we used lymphocytes from healthy individuals to show that polymorphisms in ERCC1 and ERCC2 are directly associated with decreased DNA repair efficiency. METHODS: ERCC1 (rs3212986 and rs11615 and ERCC2 (rs13181, rs1799793 and rs238406 were genotyped in 818 healthy Han individuals from the northeast of China. BPDE induced DNA adducts in lymphocytes were assessed by high performance liquid chromatography (HPLC in 282 randomly selected participants. The effect of ERCC1 rs3212986 and ERCC2 rs238406 on DNA damage caused by B[a]P was assessed with a modified comet assay. RESULTS: We found that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 were associated with the high levels of BPDE-DNA adducts. Especially ERCC1 rs3212986 A-allele variant was significantly associated with the high BPDE-DNA adducts. Haplotype analysis showed that the ERCC1 haplotype AC (OR = 2.36, 95% CI = 1.84-2.97, ERCC2 haplotype AGA (OR = 1.51, 95% CI = 1.06-2.15 and haplotype block AGAAC (OR = 5.28, 95% CI = 2.95-9.43, AGCAC (OR = 1.35 95% CI = 1.13-1.60 were linked with high BPDE-DNA adducts. In addition, we found that the combined minor alleles of ERCC1 rs3212986 and ERCC2 rs238406 were associated with a reduced DNA repair capacity. CONCLUSIONS: Our results suggest that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 are associated with decreased repair efficiency of BPDE induced DNA damage, and may be predictive for an individual's DNA repair capacity in response to environmental carcinogens.

  9. Exposure to meat-derived carcinogens and bulky DNA adduct levels in normal-appearing colon mucosa.

    Science.gov (United States)

    Ho, Vikki; Brunetti, Vanessa; Peacock, Sarah; Massey, Thomas E; Godschalk, Roger W L; van Schooten, Frederik J; Ashbury, Janet E; Vanner, Stephen J; King, Will D

    2017-09-01

    Meat consumption is a risk factor for colorectal cancer. This research investigated the relationship between meat-derived carcinogen exposure and bulky DNA adduct levels, a biomarker of DNA damage, in colon mucosa. Least squares regression was used to examine the relationship between meat-derived carcinogen exposure (PhIP and meat mutagenicity) and bulky DNA adduct levels in normal-appearing colon tissue measured using 32 P-postlabelling among 202 patients undergoing a screening colonoscopy. Gene-diet interactions between carcinogen exposure and genetic factors relevant to biotransformation and DNA repair were also examined. Genotyping was conducting using the MassARRAY ® iPLEX ® Gold SNP Genotyping assay. PhIP and higher meat mutagenicity exposures were not associated with levels of bulky DNA adducts in colon mucosa. The XPC polymorphism (rs2228001) was found to associate with bulky DNA adduct levels, whereby genotypes conferring lower DNA repair activity were associated with higher DNA adduct levels than the normal activity genotype. Among individuals with genotypes associated with lower DNA repair (XPD, rs13181 and rs1799179) or detoxification activity (GSTP1, rs1695), higher PhIP or meat mutagenicity exposures were associated with higher DNA adduct levels. Significant interactions between the XPC polymorphism (rs2228000) and both dietary PhIP and meat mutagenicity on DNA adduct levels was observed, but associations were inconsistent with the a priori hypothesized direction of effect. Exposure to meat-derived carcinogens may be associated with increased DNA damage occurring directly in the colon among genetically susceptible individuals. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Maternal diet and dioxin-like activity, bulky DNA adducts and micronuclei in mother-newborns

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Marie, E-mail: mpedersen@creal.cat [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark); Halldorsson, Thorhallur I., E-mail: lur@ssi.dk [Faculty of Food Science and Nutrition, School of Health Sciences, University of Iceland Reykjavik (Iceland); Center for Fetal Programming, Department of Epidemiology, Statens Serum Institute, Copenhagen (Denmark); Autrup, Herman, E-mail: ha@mil.au.dk [School of Public Health, Department of Environmental and Occupational Medicine, Aarhus University, Aarhus (Denmark); Brouwer, Abraham, E-mail: Bram.Brouwer@bds.nl [BioDetection Systems B.V., Amsterdam (Netherlands); Besselink, Harrie, E-mail: Harrie.Besselink@bds.nl [BioDetection Systems B.V., Amsterdam (Netherlands); Loft, Steffen, E-mail: stl@sund.ku.dk [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark); Knudsen, Lisbeth E., E-mail: liek@sund.ku.dk [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark)

    2012-06-01

    Maternal diet can contribute to carcinogenic exposures and also modify effects of environmental exposures on maternal and fetal genetic stability. In this study, associations between maternal diet and the levels of dioxin-like plasma activity, bulky DNA adducts in white blood cells and micronuclei (MN) in lymphocytes from mother to newborns were examined. From 98 pregnant women living in the greater area of Copenhagen, Denmark in 2006-2007, maternal peripheral blood and umbilical cord blood were collected, together with information on health, environmental exposure and lifestyle. Maternal diet was estimated on the basis of maternal food frequency questionnaire (FFQ) completed by the end of pregnancy. Biomarkers were detected in paired blood samples through the dioxin-responsive chemical-activated luciferase expression (CALUX){sup Registered-Sign} bioassay, {sup 32}P-postlabelling technique and cytokinesis-block MN assay. Maternal preference for meats with dark surface were significantly associated with higher bulky DNA adducts in both maternal ({beta} 95%CI; 0.46 (0.08, 0.84)) and cord blood ({beta} 95%CI; 0.46 (0.05, 0.86)) before and after adjustment for potential confounders. No other significant associations between the 18 dietary variables and the biomarkers measured in maternal and fetal samples were identified. The present study suggests that maternal intake of meats with dark surface contributes to the bulky DNA adduct levels in maternal and umbilical cord blood. Relationship between food preparation and bulky DNA adducts appear to be captured by a FFQ while potential associations for other biomarkers might be more complex or need larger sample size.

  11. Adducts in sperm protamine and DNA (deoxyribonuclease) vs. mutation frequency

    Energy Technology Data Exchange (ETDEWEB)

    Sega, G.A.

    1990-01-01

    In mammals, variability in the genetic sensitivity of different germ-cell stages to mutagens could be the result of how much chemical reaches the different stages, what molecular targets may be affected in the different stages and whether or not repair of lesions occurs. In the mouse, several mutagens have been found that cause their greatest genetic damage in late-spermatid and early-spermatozoa stages and that also bind very strongly to the protamine in these stages. Chemicals which are less genetically damaging to these stages have been found to have much less affinity for protamine. Furthermore, the level of chemical binding to DNA in late-spermatid and early-spermatozoa stages has not been correlated with the level of induced genetic damage, although DNA breakage in these sensitive stages has been shown to increase. This DNA damage is believed to indirectly result from chemical binding to sulfhydryl groups in protamine which prevents normal chromatin condensation within the sperm nucleus. 16 refs., 5 figs.

  12. Polycyclic aromatic hydrocarbon-DNA adducts in cervix of women infected with carcinogenic human papillomavirus types: An immunohistochemistry study

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, M. Margaret [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States)], E-mail: prattm@mail.nih.gov; Sirajuddin, Paul; Poirier, Miriam C. [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States); Schiffman, Mark [Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD (United States); Glass, Andrew G.; Scott, David R.; Rush, Brenda B. [Northwest Kaiser Permanente, Portland, OR (United States); Olivero, Ofelia A. [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States); Castle, Philip E. [Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD (United States)

    2007-11-01

    Among women infected with carcinogenic human papillomavirus (HPV), there is a two- to five-fold increased risk of cervical precancer and cancer in women who smoke compared to those who do not smoke. Because tobacco smoke contains carcinogenic polycyclic aromatic hydrocarbons (PAHs), it was of interest to examine human cervical tissue for PAH-DNA adduct formation. Here, we measured PAH-DNA adduct formation in cervical biopsies collected in follow-up among women who tested positive for carcinogenic HPV at baseline. A semi-quantitative immunohistochemistry (IHC) method using antiserum elicited against DNA modified with r7,t8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) was used to measure nuclear PAH-DNA adduct formation. Cultured human cervical keratinocytes exposed to 0, 0.153, or 0.331 {mu}M BPDE showed dose-dependent increases in r7,t8,t9-trihydroxy-c-10-(N{sup 2}deoxyguanosyl)-7,8,9, 10-tetrahydro-benzo[a]pyrene (BPdG) adducts. For BPdG adduct analysis, paraffin-embedded keratinocytes were stained by IHC with analysis of nuclear color intensity by Automated Cellular Imaging System (ACIS) and, in parallel cultures, extracted DNA was assayed by quantitative BPDE-DNA chemiluminescence immunoassay (CIA). For paraffin-embedded samples from carcinogenic HPV-infected women, normal-appearing cervical squamous epithelium suitable for scoring was found in samples from 75 of the 114 individuals, including 29 cases of cervical precancer or cancer and 46 controls. With a lower limit of detection of 20 adducts/10{sup 8} nucleotides, detectable PAH-DNA adduct values ranged from 25 to 191/10{sup 8} nucleotides, with a median of 75/10{sup 8} nucleotides. PAH-DNA adduct values above 150/10{sup 8} nucleotides were found in eight samples, and in three samples adducts were non-detectable. There was no correlation between PAH-DNA adduct formation and either smoking or case status. Therefore, PAH-DNA adduct formation as measured by this methodology did not appear

  13. Bulky carcinogen-DNA adducts and exposure to environmental and occupational sources of polycyclic aromatic hydrocarbons. Influence of susceptibility genotypes on adduct level

    Energy Technology Data Exchange (ETDEWEB)

    Sabro Nielsen, P.

    1996-12-31

    PAH exposure, whether it is of occupational or environmental origin, is thought to result in an elevated risk of cancer especially in the lungs. DNA damage is considered an important step in the carcinogenic effect of PAH. Hence, methods that elucidate the steps in the carcinogenic process are important to understand the action of PAH. It may prove useful in the exposure assessment and in combination with classical epidemiological methods give better basis for risk estimation. The objective in this thesis was to evaluate the feasibility of the {sup 32}P-postlabeling method to detect carcinogen-DNA adducts for assessing exposure to DNA damaging compounds in different occupationally and environmentally exposed groups. The studies included groups, that have an elevated cancer risk due to occupational exposure to PAH. Exposure levels were supposed to be relatively low according to reports on occupational and environmental air quality programs. Another aim was to evaluate the influence of polymorphisms in metabolizing enzyme genes on DNA adduct levels. A third objective was to establish some kind of baseline DNA adduct level for individuals with supposed low exposure, and compare it to the more exposed groups. A fourth aim in these studies was to examine if biomarkers of genotoxic exposure could be useful in epidemiological studies to identify groups at risk and thereby contribute with better exposure estimates in the study of PAH related cancer risk. (EG).

  14. Formation of Dopamine Quinone-DNA Adducts and their Potential Role in the Etiology of Parkinson’s Disease

    Science.gov (United States)

    Zahid, Muhammad; Saeed, Muhammad; Yang, Li; Beseler, Cheryl; Rogan, Eleanor; Cavalieri, Ercole L.

    2015-01-01

    Summary The neurotransmitter dopamine is oxidized to its quinone (DA-Q), which at neutral pH undergoes intramolecular cyclization by 1,4-Michael addition, followed by oxidation to form leukochrome, then aminochrome, and finally neuromelanin. At lower pH, the amino group of DA is partially protonated, allowing the competitive intermolecular 1,4-Michael addition with nucleophiles in DNA to form the depurinating adducts, DA-6-N3Ade and DA-6-N7Gua. Catechol estrogen-3,4-quinones react by 1,4-Michael addition to form the depurinating 4-hydroxyestrone(estradiol)-1-N3Ade [4-OHE1(E2)-1-N3Ade] and 4-OHE1(E2)-1-N7Gua adducts, which are implicated in the initiation of breast and other human cancers. The effect of pH was studied by reacting tyrosinase-activated DA with DNA and measuring the formation of depurinating adducts. The most adducts were formed at pH 4, 5, and 6, and their level was nominal at pH 7 and 8. The N3Ade adduct depurinated instantaneously, but N7Gua had a half-life of 3 H. The slow loss of the N7Gua adduct is analogous to that observed in previous studies of natural and synthetic estrogens. The antioxidants N-acetylcysteine and resveratrol efficiently blocked formation of the DA-DNA adducts. Thus, slightly acidic conditions render competitive the reaction of DA-Q with DNA to form depurinating adducts. We hypothesize that formation of these adducts could lead to mutations that initiate Parkinson’s disease. If so, use of N-acetylcysteine and resveratrol as dietary supplements may prevent initiation of this disease. PMID:22045657

  15. Enzymology of repair of DNA adducts produced by N-nitroso compounds

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.B.; Cao, E.H.; Delihas, N.C.

    1983-01-01

    The biological effects of DNA adducts depend on their nature, and on their half-lives relative to the rates of DNA replication and transcription. Their half-lives are determined by the rates of spontaneous decay, such as depurination, and the rates of enzymatic repair of the adducts or their decay products. The principle modes of repair of methylating and ethylating agents are by glycosylase catalyzed depurination of 7-alkylguanine and 3-alkyladenine and by the dealkalation of O/sup 6/-alkylguanine. Repair by dealkylation cannot be detected by the standard methods used to measure DNA repair, but it is easy to estimate the acceptor activity in cell extracts by measuring the transfer of radioactive O/sup 6/-alkyl groups in an exogenous DNA to protein. In extracts of cells treated with alkylating agents the activity is depressed because the endogenous DNA is rapidly dealkylated, using up the acceptor activity. In many cell types the decrease in activity is followed by an increase to the normal constitutive level. In other cells there is no such adaptive response. Differences in constitutive levels of methyl accepting activity in extracts of human lymphocytes and on the acceptor activity in lung macrophages from smokers (low activity) and non-smokers (high activity) have been observed. 46 references.

  16. Dynamics and mechanism of DNA repair in a biomimetic system: flavin-thymine dimer adduct.

    Science.gov (United States)

    Kao, Ya-Ting; Song, Qin-Hua; Saxena, Chaitanya; Wang, Lijuan; Zhong, Dongping

    2012-01-25

    To mimic photolyase for efficient repair of UV-damaged DNA, numerous biomimetic systems have been synthesized, but all show low repair efficiency. The molecular mechanism of this low-efficiency process is still poorly understood. Here we report our direct mapping of the repair processes of a flavin-thymine dimer adduct with femtosecond resolution. We followed the entire dynamic evolution and observed direct electron transfer (ET) from the excited flavin to the thymine dimer in 79 ps. We further observed two competitive pathways, productive dimer ring splitting within 435 ps and futile back-ET in 95 ps. Our observations reveal that the underlying mechanism for the low repair quantum yield of flavin-thymine dimer adducts is the short-lived excited flavin moiety and the fast dynamics of futile back-ET without repair. © 2012 American Chemical Society

  17. Nuclear magnetic resonance studies of an N2-guanine adduct derived from the tumorigen dibenzo[a,l]pyrene in DNA: impact of adduct stereochemistry, size, and local DNA sequence on solution conformations.

    Science.gov (United States)

    Rodríguez, Fabián A; Liu, Zhi; Lin, Chin H; Ding, Shuang; Cai, Yuqin; Kolbanovskiy, Alexander; Kolbanovskiy, Marina; Amin, Shantu; Broyde, Suse; Geacintov, Nicholas E

    2014-03-25

    The dimensions and arrangements of aromatic rings (topology) in adducts derived from the reactions of polycyclic aromatic hydrocarbon (PAH) diol epoxide metabolites with DNA influence the distortions and stabilities of double-stranded DNA, and hence their recognition and processing by the human nucleotide excision repair (NER) system. Dibenzo[a,l]pyrene (DB[a,l]P) is a highly tumorigenic six-ring PAH, which contains a nonplanar and aromatic fjord region that is absent in the structurally related bay region five-ring PAH benzo[a]pyrene (B[a]P). The PAH diol epoxide-DNA adducts formed include the stereoisomeric 14S and 14R trans-anti-DB[a,l]P-N(2)-dG and the stereochemically analogous 10S- and 10R-B[a]P-N(2)-dG (B[a]P-dG) guanine adducts. However, nuclear magnetic resonance (NMR) solution studies of the 14S-DB[a,l]P-N(2)-dG adduct in DNA have not yet been presented. Here we have investigated the 14S-DB[a,l]P-N(2)-dG adduct in two different sequence contexts using NMR methods with distance-restrained molecular dynamics simulations. In duplexes with dC opposite the adduct deleted, a well-resolved base-displaced intercalative adduct conformation can be observed. In full duplexes, in contrast to the intercalated 14R stereoisomeric adduct, the bulky DB[a,l]P residue in the 14S adduct is positioned in a greatly widened and distorted minor groove, with significant disruptions and distortions of base pairing at the lesion site and two 5'-side adjacent base pairs. These unique structural features are significantly different from those of the stereochemically analogous but smaller B[a]P-dG adduct. The greater size and different topology of the DB[a,l]P aromatic ring system lead to greater structurally destabilizing DNA distortions that are partially compensated by stabilizing DB[a,l]P-DNA van der Waals interactions, whose combined effects impact the NER response to the adduct. These structural results broaden our understanding of the structure-function relationship in NER.

  18. Ultrasensitive UPLC-MS/MS method for analysis of etheno-DNA adducts in human white blood cells.

    Science.gov (United States)

    Li, H; Cui, S; Wang, S; Jiang, X; Zhang, S; Zhang, R; Fu, P P; Sun, X

    2015-01-01

    Etheno-DNA adducts are generated by interaction of cellular DNA with exogenous environmental carcinogens and end products of lipid peroxidation. It has been determined that 1,N(6)-etheno-2'-deoxyadenosine (εdA) and 3,N(4)-etheno-2'-deoxycytidine (εdC) adducts formed in human white blood cells can be used to serve as biomarkers of genetic damage mediated by oxidative stress. In this study, we developed an ultrasensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method used to detect and quantify εdA and dC adducts in human white blood cells. The percent recoveries of εdA and dC adducts were found to be 88.9% ± 2.8 and 95.7% ± 3.7, respectively. The detection limits were ∼ 1.45 fmol for εdA and ∼ 1.27 fmol for εdC in 20 μg of human white blood cell DNA samples, both εdA and εdC adducts could be detected using only ∼ 5 μg of DNA per sample. For validation of the method, 34 human blood cell DNA samples were assayed and the results revealed a significant difference (P blood cell DNA samples; background levels of εdA and εdC could be reproducibly detected. The ultrasensitive and simple detection method is thus suitable for applications in human biomonitoring and molecular epidemiology studies.

  19. Detection of benzo[a]pyrene-guanine adducts in single-stranded DNA using the α-hemolysin nanopore

    Science.gov (United States)

    Perera, Rukshan T.; Fleming, Aaron M.; Johnson, Robert P.; Burrows, Cynthia J.; White, Henry S.

    2015-02-01

    The carcinogenic precursor benzo[a]pyrene (BP), a polycyclic aromatic hydrocarbon, is released into the environment through the incomplete combustion of hydrocarbons. Metabolism of BP in the human body yields a potent alkylating agent (benzo[a]pyrene diol epoxide, BPDE) that reacts with guanine (G) in DNA to form an adduct implicated in cancer initiation. We report that the α-hemolysin (αHL) nanopore platform can be used to detect a BPDE adduct to G in synthetic oligodeoxynucleotides. Translocation of a 41-mer poly-2‧-deoxycytidine strand with a centrally located BPDE adduct to G through αHL in 1 M KCl produces a unique multi-level current signature allowing the adduct to be detected. This readily distinguishable current modulation was observed when the BPDE-adducted DNA strand translocated from either the 5‧ or 3‧ directions. This study suggests that BPDE adducts and other large aromatic biomarkers can be detected with αHL, presenting opportunities for the monitoring, quantification, and sequencing of mutagenic compounds from cellular DNA samples.

  20. Maternal diet and dioxin-like activity, bulky DNA adducts and micronuclei in mother-newborns

    DEFF Research Database (Denmark)

    Pedersen, Marie; Halldorsson, Thorhallur I; Autrup, Herman

    2012-01-01

    Maternal diet can contribute to carcinogenic exposures and also modify effects of environmental exposures on maternal and fetal genetic stability. In this study, associations between maternal diet and the levels of dioxin-like plasma activity, bulky DNA adducts in white blood cells and micronuclei...... (MN) in lymphocytes from mother to newborns were examined. From 98 pregnant women living in the greater area of Copenhagen, Denmark in 2006-2007, maternal peripheral blood and umbilical cord blood were collected, together with information on health, environmental exposure and lifestyle. Maternal diet...

  1. DNA adducts and cancer risk in prospective studies: a pooled analysis and a meta-analysis

    DEFF Research Database (Denmark)

    Veglia, Fabrizio; Loft, Steffen; Matullo, Giuseppe

    2008-01-01

    in which bulky DNA adducts have been measured in blood samples collected from healthy subjects (N = 1947; average follow-up 51-137 months). In addition, we have performed a meta-analysis by identifying all articles on the same subject published up to the end of 2006, including case-control studies......). The association was evident only in current smokers and was absent in former smokers. Also the meta-analysis, which included both lung and bladder cancers, showed a statistically significant association in current smokers, whereas the results in never smokers were equivocal; in former smokers, no association...

  2. Mainstream and sidestream cigarette smoke-induced DNA adducts in C7Bl and DBA mice.

    OpenAIRE

    Gairola, C G; Wu, H; Gupta, R C; Diana, J N

    1993-01-01

    Exposure to environmental tobacco smoke (ETS), which is largely composed of the sidestream cigarette smoke, has been implicated in increased incidence of cancer among nonsmokers. The present study was conducted to compare the potential of mainstream and sidestream cigarette smoke to induce DNA adducts in mice. Groups of female C57Bl and DBA mice were exposed twice daily for 65-70 weeks to mainstream or sidestream smoke from the University of Kentucky reference cigarettes (2R1) in a nose-only ...

  3. [Association of etheno-DNA adduct and DNA methylation level among workers exposed to diesel engine exhaust].

    Science.gov (United States)

    Shen, M L; He, Z N; Zhang, X; Duan, H W; Niu, Y; Bin, P; Ye, M; Meng, T; Dai, Y F; Yu, S F; Chen, W; Zheng, Y X

    2017-06-06

    Objective: To investigate the association between etheno-DNA adduct and the promoter of DNA methylation levels of cyclin dependent kinase inhibitor 2A (P16), Ras association domain family 1 (RASSF1A) and O-6-methylguanine-DNA methyltransferase (MGMT) in workers with occupational exposure to diesel engine exhaust (DEE). Methods: We recruited 124 diesel engine testing workers as DEE exposure group and 112 water pump operator in the same area as control group in Henan province in 2012 using cluster sampling. The demographic data were obtained by questionnaire survey; urine after work and venous blood samples were collected from each subject. The urinary etheno-DNA adducts were detected using UPLC-MS/MS, including 1,N6-etheno-2'-deoxyadenosine (εdA) and 3,N4-etheno-2'-deoxycytidine(εdC). The DNA methylation levels of P16, RASSF1A, and MGMT were evaluated using bisulfite-pyrosequencing assay. The percentage of methylation was expressed as the 5-methylcytosine (5mC) over the sum of cytosines (%5mC). Spearman correlation and multiple linear regression were applied to analyze the association between etheno-DNA adducts and DNA methylation of P16, RASSF1A, and MGMT. Results: The median (P(25)-P(75)) of urinary εdA level was 230.00 (98.04-470.91) pmol/g creatinine in DEE exposure group, and 102.10 (49.95-194.48) creatinine in control group. The level of εdA was higher in DEE exposure group than control group (P0.05) . Multiple linear regression confirmed the negative correlation between εdA and DNA methylation levels of P16, RASSF1A, and MGMT in non-smoking group (β (95%CI) was -0.068 (-0.132--0.003), -0.082 (-0.159--0.004) and -0.048 (-0.090--0.007), P values were 0.039, 0.039 and 0.024, respectively). Moreover, εdC was negative associated with DNA methylation level of MGMT in non-smoking group (β (95%CI) was -0.094 (-0.179--0.008), P=0.032). Conclusion: DEE exposure could induce the increased of εdA and decreased of DNA methylation levels of P16, RASSF1A and MGMT.

  4. Protection by quercetin and quercetin-rich fruit juice against induction of oxidative DNA damage and formation of BPDE-DNA adducts in human lymphocytes

    NARCIS (Netherlands)

    Wilms, L.C.; Hollman, P.C.H.; Boots, A.W.; Kleinjans, J.C.S.

    2005-01-01

    Flavonoids are claimed to protect against cardiovascular disease, certain forms of cancer and ageing, possibly by preventing initial DNA damage. Therefore, we investigated the protective effects of the flavonoid quercetin against the formation of oxidative DNA damage and bulky DNA adducts in human

  5. Myeloperoxidase - 463A variant reduces benzo(a)pyrene diol epoxide DNA adducts in skin of coal tar treated patients

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, M.; Godschalk, R.; Alexandrov, K.; Cascorbi, I.; Kriek, E.; Ostertag, J.; Van Schooten, F.J.; Bartsch, H. [German Cancer Research Center, Heidelberg (Germany). Div. of Toxicology & Cancer Risk Factors

    2001-07-01

    The skin of atopic dermatitis patients provides an excellent model to study the role of inflammation in benzo(a)pyrene (BaP) activation, since these individuals are often topically treated with ointments containing high concentrations of BaP. The authors determined, by HPLC with fluorescence detection, the BaP diol epoxide (BPDE)-DNA adduct levels in human skin after topical treatment with coal tar and their modulation by the -453G into A myeloperoxidase (MPO) polymorphism, which reduces MPO mRNA expression. The data show for the first time: (i) the in vivo formation of BPDE-DNA adducts in human skin treated with coal tar; (ii) that the MPO-463AA/AG genotype reduced BPDE-DNA adduct levels in human skin.

  6. Methyleugenol DNA adducts in human liver are associated with SULT1A1 copy number variations and expression levels.

    Science.gov (United States)

    Tremmel, Roman; Herrmann, Kristin; Engst, Wolfram; Meinl, Walter; Klein, Kathrin; Glatt, Hansruedi; Zanger, Ulrich M

    2017-10-01

    Methyleugenol is a rodent hepatocarcinogen occurring in many herbs and spices as well as essential oils used for flavoring. Following metabolic activation by cytochromes P450 (CYPs) and sulfotransferases (SULTs), methyleugenol can form DNA adducts. Previously, we showed that DNA adduct formation by methyleugenol in mouse liver is dependent on SULT1A1 expression and that methyleugenol DNA adducts are abundant in human liver specimens. In humans, SULT1A1 activity is affected by genetic polymorphisms, including single-nucleotide polymorphisms (SNPs) and copy number variations (CNVs). Here we investigated the relationship between individual methyleugenol DNA adduct levels and SULT1A1 in human liver samples. Using isotope-dilution ultraperformance liquid chromatography coupled with tandem mass spectrometry, we quantified methyleugenol DNA adducts in 121 human surgical liver samples. Frequent CNVs, including deletions (f = 3.3%) and duplications (f = 36.4%) of SULT1A1, were identified using qPCR and TaqMan assays in the donors' genomic DNA. SULT1A1 mRNA and protein levels were quantified using microarray data and Western blot analysis, respectively. Methyleugenol DNA adducts were detected in all 121 liver samples studied. Their levels varied 122-fold between individuals and were significantly correlated to both mRNA and protein levels of SULT1A1 (r s = 0.43, and r s = 0.44, respectively). Univariate and multivariate statistical analysis identified significant associations of SULT1A1 CNVs with mRNA (p = 1.7 × 10-06) and protein (p = 4.4 × 10- 10) levels as well as methyleugenol DNA adduct levels (p = 0.003). These data establish the importance of SULT1A1 genotype for hepatic methyleugenol DNA adducts in humans, and they confirm a strong impact of SULT1A1 CNVs on SULT1A1 hepatic phenotype.

  7. Base-Displaced Intercalated Structure of the N-(2′-Deoxyguanosin-8-yl)-3-aminobenzanthrone DNA Adduct

    Science.gov (United States)

    Politica, Dustin A.; Malik, Chanchal K.; Basu, Ashis K.; Stone, Michael P.

    2016-01-01

    3-Nitrobenzanthrone (3-NBA), an environmental mutagen found in diesel exhaust and a suspected carcinogen, undergoes metabolic reduction followed by reaction with DNA to form aminobenzanthrone (ABA) adducts, with the major alkylation product being N-(2′-deoxyguanosin-8-yl)-3-aminobenzanthrone (C8-dG-ABA). Site-specific synthesis of the C8-dG-ABA adduct in the oligodeoxynucleotide 5'-d(GTGCXTGTTTGT)-3':5'-d(ACAAACACGCAC)-3'; X = C8-dG-ABA adduct, including codons 272-275 of the p53 gene, has allowed for investigation into the structural and thermodynamic properties of this adduct. The conformation of the C8-dG-ABA adduct was determined using NMR spectroscopy and was refined using molecular dynamics (MD) calculations restrained by experimentally determined interproton distance restraints obtained from NOE experiments. The refined structure revealed that the C8-dG-ABA adduct formed a base-displaced intercalated conformation. The adducted guanine was shifted into the syn conformation about the glycosidic bond. The 5'- and 3'-neighboring base pairs remained intact. While this facilitated π-stacking interactions between the ABA moiety and neighboring bases, the thermal melting temperature (Tm) of the adduct-containing duplex showed a decrease of 11 °C as compared to the corresponding unmodified oligodeoxynucleotide duplex. Overall, in this sequence, the base-displaced intercalated conformation of the C8-dG-ABA lesion bears similarity to structures of other arylamine C8-dG adducts. However, in this sequence, the base-displaced intercalated conformation for the C8-dG-ABA adduct differs from the conformation of the N2-dG-ABA adduct reported by de los Santos and co-workers, which oriented in the minor groove towards the 5' end of the duplex, with the modified guanine remaining in the anti conformation about the glyosidic torsion angle, and the complementary base remaining within the duplex. The results are discussed in relationship to differences between the C8-dG-ABA and

  8. Probenecid, an inhibitor of transmembrane organic anion transporters, alters tissue distribution of DNA adducts in 1-hydroxymethylpyrene-treated rats.

    Science.gov (United States)

    Monien, Bernhard H; Müller, Carolin; Bakhiya, Nadiya; Donath, Claudia; Frank, Heinz; Seidel, Albrecht; Glatt, Hansruedi

    2009-07-28

    1-Methylpyrene (1-MP), an abundant alkylated polycyclic aromatic hydrocarbon, is activated by side-chain hydroxylation to 1-hydroxymethylpyrene (1-HMP) and subsequent sulfo-conjugation to electrophilic 1-sulfooxymethylpyrene (1-SMP). In rats, this activation mainly occurs in liver. 1-SMP may react with hepatic DNA or be exported into the blood circulation to reach other tissues, in particular kidneys. Findings with recombinant cell lines suggest that renal 1-SMP uptake proceeds via organic anion transporters (OATs). Here, we tested the hypothesis that probenecid, a characteristic OAT inhibitor, interferes with kidney damage brought about by 1-SMP formed in rats. 1-HMP was administered intraperitoneally to 30 rats, half of which were co-treated with probenecid. The tissue distribution of DNA adducts was analyzed using (32)P-postlabeling and isotope dilution LC-MS/MS for the detection of the adducts N(2)-(1-methylpyrenyl)-2'-deoxyguanosine and N(6)-(1-methylpyrenyl)-2'-deoxyadenosine. In rats treated solely with 1-HMP, adduct levels in kidney tissue were about 3-fold and 8-fold higher than those in liver and lung, respectively. After co-treatment with probenecid, hepatic and pulmonary adduct levels were 12-fold and 4-fold elevated, respectively, whereas renal adduct levels were slightly lower compared to those of rats receiving 1-HMP alone. Moreover, serum levels of 1-SMP were increased 23-fold in animals pre-treated with probenecid. The differential effects on hepatic and pulmonary adduct levels suggest that not only renal OATs, but also additional anion transporters, e.g. those mediating the hepatic export of 1-SMP into the bile, were inhibited. Thus, transmembrane transport proteins play a crucial role in the distribution of reactive phase II metabolites, and thereby in tissue allocation of DNA adducts.

  9. Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA

    Energy Technology Data Exchange (ETDEWEB)

    Hang, Bo; Rodriguez, Ben; Yang, Yanu; Guliaev, Anton B.; Chenna, Ahmed

    2010-06-14

    Benzene, a ubiquitous human carcinogen, forms DNA adducts through its metabolites such as p-benzoquinone (p-BQ) and hydroquinone (HQ). N(2)-(4-Hydroxyphenyl)-2'-deoxyguanosine (N(2)-4-HOPh-dG) is the principal adduct identified in vivo by (32)P-postlabeling in cells or animals treated with p-BQ or HQ. To study its effect on repair specificity and replication fidelity, we recently synthesized defined oligonucleotides containing a site-specific adduct using phosphoramidite chemistry. We here report the repair of this adduct by Escherichia coli UvrABC complex, which performs the initial damage recognition and incision steps in the nucleotide excision repair (NER) pathway. We first showed that the p-BQ-treated plasmid was efficiently cleaved by the complex, indicating the formation of DNA lesions that are substrates for NER. Using a 40-mer substrate, we found that UvrABC incises the DNA strand containing N(2)-4-HOPh-dG in a dose- and time-dependent manner. The specificity of such repair was also compared with that of DNA glycosylases and damage-specific endonucleases of E. coli, both of which were found to have no detectable activity toward N(2)-4-HOPh-dG. To understand why this adduct is specifically recognized and processed by UvrABC, molecular modeling studies were performed. Analysis of molecular dynamics trajectories showed that stable G:C-like hydrogen bonding patterns of all three Watson-Crick hydrogen bonds are present within the N(2)-4-HOPh-G:C base pair, with the hydroxyphenyl ring at an almost planar position. In addition, N(2)-4-HOPh-dG has a tendency to form more stable stacking interactions than a normal G in B-type DNA. These conformational properties may be critical in differential recognition of this adduct by specific repair enzymes.

  10. Mutagenic properties of the 8-amino-2'-deoxyguanosine DNA adduct in mammalian cells.

    Science.gov (United States)

    Tan, X; Suzuki, N; Johnson, F; Grollman, A P; Shibutani, S

    1999-01-01

    The DNA adduct 8-amino-2'-deoxyguanosine (8-amino-dG) is found in liver DNA of rats treated with the hepatocarcinogen 2-nitropropane. Site-specifically modified oligodeoxynucleotides were used to explore the mutagenic potential of 8-amino-dG in simian kidney (COS-7) cells. Oligodeoxynucleotides (5'-TCCTCCTX1G2CCTCTC and 5'-TCCTCCTG1X2CCTCTC, X = dG or 8-amino-dG) with the lesion positioned at codon 60 or 61 of the non-coding strand of the human c-Ha- ras1 gene were inserted into single-stranded phagemid vectors and transfected into COS-7 cells. The progeny plasmid obtained was used to transform Escherichia coli DH10B. Transformants were analyzed by oligodeoxynucleotide hybridization and DNA sequencing to establish the mutation frequency and spectrum produced by the modified base. The correct base, dCMP, was incorporated preferentially opposite 8-amino-dG at X1and X2. When 8-amino-dG was at X1, targeted GNH2-->T transversions were detected, along with smaller numbers of GNH2-->A transitions and GNH2-->C transversions. When the adduct was at X2, only GNH2-->T transversions were observed. The frequencies of targeted mutation at X1and X2were 2.7 and 1.7%, respectively. Mutation frequency and mutagenic spectrum were sequence context dependent. In addition, non-targeted G-->T transversions, accompanied by some G-->A transitions, were detected 5' to 8-amino-dG when the lesion was at X2. We conclude that 8-amino-dG is a mutagenic lesion, generating G-->T and G-->C transversions and G-->A transitions in mammalian cells. PMID:10325419

  11. Increased micronuclei and bulky DNA adducts in cord blood after maternal exposures to traffic-related air pollution

    DEFF Research Database (Denmark)

    Pedersen, M.; Wichmann, J.; Autrup, H.

    2009-01-01

    umbilical cords, concurrently collected at the time of planned Caesarean section. Modeled residential traffic density, a proxy measure of traffic-related air pollution exposures, was validated by indoor levels of nitrogen dioxide and polycyclic aromatic hydrocarbons in 42 non-smoking homes. DNA adduct......Exposure to traffic-related air pollution in urban environment is common and has been associated with adverse human health effects. In utero exposures that result in DNA damage may affect health later in life. Early effects of maternal and in utero exposures to traffic-related air pollution were...... for potential confounders and effect modifiers. For the first time increased bulky DNA adducts and MN in cord blood after maternal exposures to traffic-related air pollution are found, demonstrating that these transplacental environmental exposures induce DNA damage in newborns. Given that increased DNA damage...

  12. Immunoperoxidase detection of polycyclic aromatic hydrocarbon-DNA adducts in mouth floor and buccal mucosa cells of smokers and nonsmokers

    NARCIS (Netherlands)

    Besaratinia, A.; Besarati Nia, A.; van Straaten, H. W.; Godschalk, R. W.; van Zandwijk, N.; Balm, A. J.; Kleinjans, J. C.; van Schooten, F. J.

    2000-01-01

    Tobacco smoking is a major risk factor for oral cancer; mouth floor and buccal mucosa are among the most and least cancer-prone subsites, respectively, in the oral cavity. We investigated the applicability of immunohistochemistry of smoking-induced DNA adducts in oral cells for assessing the

  13. Polycyclic aromatic hydrocarbon-DNA adducts in Beluga whales from the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, A.; Payne, J.F.; Fancey, L.L. [Department of Fisheries and Oceans, St. John`s Newfoundland (Canada)] [and others

    1997-09-01

    The Arctic is still relatively pristine in nature, but it is also vulnerable to pollution because contaminants originating from midlatitudes are transported to the Arctic by atmospheric processes, ocean currents, and river. Recognition of this fact of Arctic vulnerability has resulted in a Declaration on the Protection of the Arctic Environment by eight Arctic countries. A manifest aim of this declaration is to develop an Arctic Monitoring and Assessment Program. We report here on the presence of measurable levels of polycyclic aromatic hydrocarbon-DNA adducts, including relatively high levels in Arctic beluga (Delphinapterus leucas). These results lend support to the value of developing biological assessment programs for Arctic wildlife. 15 refs., 1 tab.

  14. Titanium dioxide nanoparticles induce oxidative stress and DNA-adduct formation but not DNA-breakage in human lung cells

    Directory of Open Access Journals (Sweden)

    Schins Roel PF

    2009-06-01

    Full Text Available Abstract Titanium dioxide (TiO2, also known as titanium (IV oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ 2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS was measured acellularly (without any photocatalytic activity as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage and required reducing conditions for radical formation.

  15. Inhibition of azoxymethane-induced DNA adduct formation by Aloe arborescens var. natalensis.

    Science.gov (United States)

    Shimpo, Kan; Chihara, Takeshi; Beppu, Hidehiko; Ida, Chikako; Kaneko, Takaaki; Hoshino, Motoyuki; Kuzuya, Hiroshi

    2003-01-01

    To clarify the possible mechanisms of inhibition of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the rat colorectum by freeze-dried whole leaves of Aloe arborescens var. natalensis (Kidachi aloe) (hereinafter referred to as ALOE) and commercial crude aloin (Sigma A-0451; from Curacao aloe) (hereinafter ALOIN), we studied the effects of ALOE and ALOIN on the formation of AOM-induced DNA adducts (O6-methylguanine; O6-MeG) in rats. Male F344 rats (4 weeks old) were fed a basal diet, or experimental diets containing 5%ALOE or 0.25%ALOIN for 5 weeks. All rats were injected s.c. twice with 15 mg/kg AOM, once at the end of week 1, and once at the end of week 2. The animals were sacrificed 6 hours after the second injection to analyze DNA adducts (O6-MeG) in the colorectum. Dietary administration of ALOE significantly inhibited the O6-MeG levels (50% reduction) compared with controls, whereas the O6-MeG levels in the ALOIN-fed rats showed a tendency to decrease (by 30%), although not significantly. In this study, we also measured the enzyme activity and mRNA level of cytochrome (CYP) 2E1, known to be responsible for the activation of AOM, in rat liver. ALOE-fed rats showed significantly reduced CYP2E1 enzymatic activity (27% reduction) compared with controls. On the other hand, the activity in ALOIN-fed rats tended to decrease by 11%, although not significantly. The CYP2E1 mRNA levels in ALOE- and ALOIN-fed rats were slightly reduced (9.7% and 5.2%, respectively). These results may explain, at least in part, the previously observed inhibitory effects of ALOE and ALOIN, especially ALOE on AOM-induced ACF formation in the rat colorectum.

  16. Biomonitoring of diesel exhaust-exposed workers. DNA and hemoglobin adducts and urinary 1-hydroxypyrene as markers of exposure

    DEFF Research Database (Denmark)

    Nielsen, Per Sabro; Andreassen, Åshild; Farmer, Peter B.

    1996-01-01

    the 32P-postlabelling method with butanol and P1 enrichment procedures. Hydroxyethylvaline (HOEtVal) adducts in hemoglobin were measured by gas chromatography-mass spectrometry (GC-MS) and 1-hydroxypyrene (HPU) in urine determined using HPLC analysis. The exposed workers had significantly higher levels...... correlated with HPU but not with DNA adducts. The levels of HPU in urine were 0.11 micromol/mol creatinine compared to 0.05 in controls. All three assays applied were sensitive enough to evaluate a low level of exposure to environmental pollutants, with postlabelling and GC-MS as the most sensitive assays...

  17. The long persistence of pyrrolizidine alkaloid-derived DNA adducts in vivo: kinetic study following single and multiple exposures in male ICR mice.

    Science.gov (United States)

    Zhu, Lin; Xue, Junyi; Xia, Qingsu; Fu, Peter P; Lin, Ge

    2017-02-01

    Pyrrolizidine alkaloid (PA)-containing plants are widespread in the world and the most common poisonous plants affecting livestock, wildlife, and humans. Our previous studies demonstrated that PA-derived DNA adducts can potentially be a common biological biomarker of PA-induced liver tumor formation. In order to validate the use of these PA-derived DNA adducts as a biomarker, it is necessary to understand the basic kinetics of the PA-derived DNA adducts formed in vivo. In this study, we studied the dose-dependent response and kinetics of PA-derived DNA adduct formation and removal in male ICR mice orally administered with a single dose (40 mg/kg) or multiple doses (10 mg/kg/day) of retrorsine, a representative carcinogenic PA. In the single-dose exposure, the PA-derived DNA adducts exhibited dose-dependent linearity and persisted for up to 4 weeks. The removal of the adducts following a single-dose exposure to retrorsine was biphasic with half-lives of 9 h (t 1/2α) and 301 h (~12.5 days, t 1/2β). In the 8-week multiple exposure study, a marked accumulation of PA-derived DNA adducts without attaining a steady state was observed. The removal of adducts after the multiple exposure also demonstrated a biphasic pattern but with much extended half-lives of 176 h (~7.33 days, t 1/2α) and 1736 h (~72.3 days, t 1/2β). The lifetime of PA-derived DNA adducts was more than 8 weeks following the multiple-dose treatment. The significant persistence of PA-derived DNA adducts in vivo supports their role in serving as a biomarker of PA exposure.

  18. Translesion synthesis DNA polymerases promote error-free replication through the minor-groove DNA adduct 3-deaza-3-methyladenine.

    Science.gov (United States)

    Yoon, Jung-Hoon; Roy Choudhury, Jayati; Park, Jeseong; Prakash, Satya; Prakash, Louise

    2017-11-10

    N3-Methyladenine (3-MeA) is formed in DNA by reaction with S-adenosylmethionine, the reactive methyl donor, and by reaction with alkylating agents. 3-MeA protrudes into the DNA minor groove and strongly blocks synthesis by replicative DNA polymerases (Pols). However, the mechanisms for replicating through this lesion in human cells remain unidentified. Here we analyzed the roles of translesion synthesis (TLS) Pols in the replication of 3-MeA-damaged DNA in human cells. Because 3-MeA has a short half-life in vitro, we used the stable 3-deaza analog, 3-deaza-3-methyladenine (3-dMeA), which blocks the DNA minor groove similarly to 3-MeA. We found that replication through the 3-dMeA adduct is mediated via three different pathways, dependent upon Polι/Polκ, Polθ, and Polζ. As inferred from biochemical studies, in the Polι/Polκ pathway, Polι inserts a nucleotide (nt) opposite 3-dMeA and Polκ extends synthesis from the inserted nt. In the Polθ pathway, Polθ carries out both the insertion and extension steps of TLS opposite 3-dMeA, and in the Polζ pathway, Polζ extends synthesis following nt insertion by an as yet unidentified Pol. Steady-state kinetic analyses indicated that Polι and Polθ insert the correct nt T opposite 3-dMeA with a much reduced catalytic efficiency and that both Pols exhibit a high propensity for inserting a wrong nt opposite this adduct. However, despite their low fidelity of synthesis opposite 3-dMeA, TLS opposite this lesion replicates DNA in a highly error-free manner in human cells. We discuss the implications of these observations for TLS mechanisms in human cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Red wine consumption is inversely associated with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-DNA adduct levels in prostate.

    Science.gov (United States)

    Rybicki, Benjamin A; Neslund-Dudas, Christine; Bock, Cathryn H; Nock, Nora L; Rundle, Andrew; Jankowski, Michelle; Levin, Albert M; Beebe-Dimmer, Jennifer; Savera, Adnan T; Takahashi, Satoru; Shirai, Tomoyuki; Tang, Deliang

    2011-10-01

    In humans, genetic variation and dietary factors may alter the biological effects of exposure to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), one of the major heterocyclic amines generated from cooking meats at high temperatures that has carcinogenic potential through the formation of DNA adducts. Previously, we reported grilled red meat consumption associated with PhIP-DNA adduct levels in human prostate. In this study, we expanded our investigation to estimate the associations between beverage consumption and PhIP-DNA adduct levels in prostate for 391 prostate cancer cases. Of the 15 beverages analyzed, red wine consumption had the strongest association with PhIP-DNA adduct levels showing an inverse correlation in both tumor (P = 0.006) and nontumor (P = 0.002) prostate cells. Red wine consumption was significantly lower in African American compared with white cases, but PhIP-DNA adduct levels in prostate did not vary by race. In African Americans compared with whites, however, associations between red wine consumption and PhIP-DNA adduct levels were not as strong as associations with specific (e.g., SULT1A1 and UGT1A10 genotypes) and nonspecific (e.g., African ancestry) genetic variation. In a multivariable model, the covariate for red wine consumption explained a comparable percentage (13%-16%) of the variation in PhIP-DNA adduct levels in prostate across the two racial groups, but the aforementioned genetic factors explained 33% of the PhIP-DNA adduct variation in African American cases, whereas only 19% of the PhIP-DNA adduct variation in whites. We conclude that red wine consumption may counteract biological effects of PhIP exposure in human prostate, but genetic factors may play an even larger role, particularly in African Americans.

  20. Insights into the error bypass of 1-Nitropyrene DNA adduct by DNA polymerase ι: A QM/MM study

    Science.gov (United States)

    Li, Yanwei; Bao, Lei; Zhang, Ruiming; Tang, Xiaowen; Zhang, Qingzhu; Wang, Wenxing

    2017-10-01

    The error bypass mechanism of DNA polymerase ι toward N-(deoxyguanosin-8-yl)-1-aminopyrene adduction was studied by using quantum mechanics/molecular mechanics method. The most favorable mechanism highlights three elementary steps: proton transfer from dC to dATP, phosphoryl transfer, and deprotonation of dAMP. The phosphoryl transfer step was found to be rate-determining. The calculated average barrier (23.8 kcal mol-1) is in accordance with the experimental value (21.5 kcal mol-1). Electrostatic influence analysis indicates that residues Asp126 and Lys207 significantly suppress the error bypass while Glu127 facilitates the process. These results highlight the origins of the mutagenicity of nitrated polycyclic aromatic hydrocarbons in molecular detail.

  1. Formation of DHP-derived DNA adducts in vivo from dietary supplements and chinese herbal plant extracts containing carcinogenic pyrrolizidine alkaloids.

    Science.gov (United States)

    Chou, Ming W; Fu, Peter P

    2006-09-01

    We recently determined that the metabolism of a series of tumorigenic pyrrolizidine alkaloids resulted in the formation of a set of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts. These DHP-derived DNA adducts have been proposed as potential biomarkers of pyrrolizidine alkaloid tumorigenicity, as well as pyrrolizidine alkaloid exposure. In this paper, we report that DHP-derived DNA adducts are formed in the liver of female F344 rats, gavaged with three dietary supplements (comfrey root extract, comfrey compound oil, and coltsfoot root extract), or an extract of a Chinese herbal plant, flos farfara (Kuan Tong Hua).

  2. Epidermal cytokinetics, DNA adducts, and dermal inflammation in the mouse skin in response to repeated benzo[a]pyrene exposures.

    Science.gov (United States)

    Albert, R E; Miller, M L; Cody, T E; Talaska, G; Underwood, P; Andringa, A

    1996-01-01

    Few studies have investigated the chronic cytokinetic effects of carcinogen exposure in the mouse skin. We report two experiments involving the repeated application of benzo[a]pyrene (BaP) to the dorsal skin of female Ha/ICR mice. In the first experiment, the cytokinetic, inflammatory, and DNA adduct responses were studied daily over a 9-day period encompassing the fourth and fifth weekly applications of BaP at doses of 16, 32, and 64 micrograms. The second experiment involved the same cytokinetic measurements at 1, 3, 5, and 8 months, and the weekly BaP doses were 4, 8, and 16 micrograms. The first study showed that after each application of 32 or 64 micrograms BaP, there was a wave of slow DNA synthesis in the epidermis which peaked at 24 hr, in coincidence with a wave of BaP-DNA adducts, followed by the appearance of dead and damaged keratinocytes. For the first few days after BaP application there was a depression in the mitotic rate which recovered several days before the next BaP application. There was a predominantly monocytic dermal inflammation throughout the observation period. In the second experiment, at the lower BaP doses, there was proliferative depression at 1 month, without dermal inflammation. With continued exposure, the proliferative depression changed to a dose-dependent increase in the rate of proliferation and dermal inflammation. The level of BaP-DNA adducts was followed in the 4 micrograms/week dose group, which showed a threefold increase after 4 months with the appearance of inflammation and heightened cell proliferation. These results suggest that the delayed inflammatory reaction, possibly based on a cell-mediated immune reaction to BaP, might have been responsible for the late cytokinetic responses and the associated increase in the level of BaP-DNA adducts.

  3. Quinone-induced Enhancement of DNA Cleavage by Human Topoisomerase IIα: Adduction of Cysteine Residues 392 and 405†

    Science.gov (United States)

    Bender, Ryan P.; Ham, Amy-Joan L.; Osheroff, Neil

    2010-01-01

    Several quinone-based metabolites of drugs and environmental toxins are potent topoisomerase II poisons. These compounds act by adducting the protein, and appear to increase levels of enzyme-DNA cleavage complexes by at least two potentially independent mechanisms. Treatment of topoisomerase IIα with quinones inhibits DNA religation, and blocks the N-terminal gate of the protein by crosslinking its two protomer subunits. It is not known whether these two effects result from quinone adduction to the same amino acid residue(s) in topoisomerase IIα or whether they are mediated by modification of separate residues. Therefore, the present study identified amino acid residues in human topoisomerase IIα that are modified by quinones and determined their role in the actions of these compounds as topoisomerase II poisons. Four cysteine residues were identified by mass spectrometry as sites of quinone adduction: cys170, cys392, cys405, and cys455. Mutations (cys–>ala) were individually generated at each position. Only mutations at cys392 or cys405 reduced sensitivity (~50% resistance) to benzoquinone. Top2αC392A and top2αC405A displayed faster rates (~2–fold) of DNA religation than wild-type topoisomerase IIα in the presence of the quinone. In contrast, as determined by DNA binding, protein clamp closing, and protomer crosslinking experiments, mutations at cys392 and cys405 did not affect the ability of benzoquinone to block the N-terminal gate of topoisomerase IIα. These findings indicate that adduction of cys392 and cys405 is important for the actions of quinones against the enzyme, and increases levels of cleavage complexes primarily by inhibiting DNA religation. PMID:17298034

  4. Environmental, Dietary, Maternal, and Fetal Predictors of Bulky DNA Adducts in Cord Blood

    DEFF Research Database (Denmark)

    Pedersen, Marie; Mendez, Michelle A; Schoket, Bernadette

    2015-01-01

    and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population. RESULTS: Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p...... body mass index, delivery by cesarean section, male infant sex, low maternal intake of fruits rich in vitamin C, high intake of dairy products, and low adherence to healthy diet score were statistically significantly associated...... with higher adduct levels in adjusted models. Exposure to fine particulate matter and nitrogen dioxide was associated with significantly higher adducts in the Danish subsample only. Overall, the pooled results for THMs in water show no evidence of association with adduct levels; however, there are country...

  5. MUTAGENICITY AND DNA ADDUCT FORMATION OF PAH, NITRO-PAH, AND OXY-PAH FRACTIONS OF ATMOSPHERIC PARTICULATE MATTER FROM SAO PAULO, BRAZIL

    Science.gov (United States)

    Summary What is the study? Near roadway and immediate roadway exposures to transportation emissions gave very similar results in the Salmonella mutagenicity assay and in an assay for DNA adducts indicating that near roadway genotoxicity is not altered significantly over...

  6. Whole body exposure of mice to secondhand smoke induces dose-dependent and persistent promutagenic DNA adducts in the lung

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-In [Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010 (United States); Arlt, Volker M. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Yoon, Jae-In [Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010 (United States); Cole, Kathleen J. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Pfeifer, Gerd P. [Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010 (United States); Phillips, David H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Besaratinia, Ahmad, E-mail: ania@coh.org [Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010 (United States)

    2011-11-01

    Secondhand smoke (SHS) exposure is a known risk factor for lung cancer in lifelong nonsmokers. However, the underlying mechanism of action of SHS in lung carcinogenesis remains elusive. We have investigated, using the {sup 32}P-postlabeling assay, the genotoxic potential of SHS in vivo by determining the formation and kinetics of repair of DNA adducts in the lungs of mice exposed whole body to SHS for 2 or 4 months (5 h/day, 5 days/week), and an ensuing one-month recovery period. We demonstrate that exposure of mice to SHS elicits a significant genotoxic response as reflected by the elevation of DNA adduct levels in the lungs of SHS-exposed animals. The increases in DNA adduct levels in the lungs of SHS-exposed mice are dose-dependent as they are related to the intensity and duration of SHS exposure. After one month of recovery in clean air, the levels of lung DNA adducts in the mice exposed for 4 months remain significantly higher than those in the mice exposed for 2 months (P < 0.0005), levels in both groups being significantly elevated relative to controls (P < 0.00001). Our experimental findings accord with the epidemiological data showing that exposure to smoke-derived carcinogens is a risk factor for lung cancer; not only does the magnitude of risk depend upon carcinogen dose, but it also becomes more irreversible with prolonged exposure. The confirmation of epidemiologic data by our experimental findings is of significance because it strengthens the case for the etiologic involvement of SHS in nonsmokers' lung cancer. Identifying the etiologic factors involved in the pathogenesis of lung cancer can help define future strategies for prevention, early detection, and treatment of this highly lethal malignancy.

  7. Induction of somatic mutations but not methylated DNA adducts in λlacZ transgenic mice by dichlorvos

    NARCIS (Netherlands)

    Pletsa, V.; Steenwinkel, M.-J.S.T.; Delft, J.H.M. van; Baan, R.A.; Kyrtopoulos, S.A.

    1999-01-01

    In order to examine the in vivo genotoxic activity of dichlorvos, λlacZ transgenic mice (Muta(TM)Mouse) were treated i.p. with single (4.4 or 11 mg/kg) or multiple (5x11 mg/kg) doses of this agent and sacrificed 4 h or 14 days post-treatment for DNA adduct measurement or mutant frequency analysis,

  8. O⁶-carboxymethylguanine DNA adduct formation and lipid peroxidation upon in vitro gastrointestinal digestion of haem-rich meat.

    Science.gov (United States)

    Vanden Bussche, Julie; Hemeryck, Lieselot Y; Van Hecke, Thomas; Kuhnle, Gunter G C; Pasmans, Frank; Moore, Sharon A; Van de Wiele, Tom; De Smet, Stefaan; Vanhaecke, Lynn

    2014-09-01

    Epidemiological and clinical studies have demonstrated that the consumption of red haem-rich meat may contribute to the risk of colorectal cancer. Two hypotheses have been put forward to explain this causal relationship, i.e. N-nitroso compound (NOC) formation and lipid peroxidation (LPO). In this study, the NOC-derived DNA adduct O(6)-carboxymethylguanine (O(6)-CMG) and the LPO product malondialdehyde (MDA) were measured in individual in vitro gastrointestinal digestions of meat types varying in haem content (beef, pork, chicken). While MDA formation peaked during the in vitro small intestinal digestion, alkylation and concomitant DNA adduct formation was observed in seven (out of 15) individual colonic digestions using separate faecal inocula. From those, two haem-rich meat digestions demonstrated a significantly higher O(6)-CMG formation (p content of digested meat. The addition of myoglobin, a haem-containing protein, to the digestive simulation showed a dose-response association with O(6)-CMG (p = 0.004) and MDA (p = 0.008) formation. The results suggest the haem-iron involvement for both the LPO and NOC pathway during meat digestion. Moreover, results unambiguously demonstrate that DNA adduct formation is very prone to inter-individual variation, suggesting a person-dependent susceptibility to colorectal cancer development following haem-rich meat consumption. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. SYNTHESIS OF THE FULLY PROTECTED PHOSPHORAMIDITE OF THE BENZENE-DNA ADDUCT, N2- (4-HYDROXYPHENYL)-2'-DEOXYGUANOSINE AND INCORPORATION OF THE LATER INTO DNA OLIGOMERS

    Energy Technology Data Exchange (ETDEWEB)

    Chenna, Ahmed; Gupta, Ramesh C.; Bonala, Radha R.; Johnson, Francis; Huang, Bo

    2008-06-09

    N2-(4-Hydroxyphenyl)-2'-deoxyguanosine-5'-O-DMT-3'-phosphoramidite has been synthesized and used to incorporate the N2-(4-hydroxyphenyl)-2'-dG (N2-4-HOPh-dG) into DNA, using solid-state synthesis technology. The key step to obtaining the xenonucleoside is a palladium (Xantphos-chelated) catalyzed N2-arylation (Buchwald-Hartwig reaction) of a fully protected 2'-deoxyguanosine derivative by 4-isobutyryloxybromobenzene. The reaction proceeded in good yield and the adduct was converted to the required 5'-O-DMT-3'-O-phosphoramidite by standard methods. The latter was used to synthesize oligodeoxynucleotides in which the N2-4-HOPh-dG adduct was incorporated site-specifically. The oligomers were purified by reverse-phase HPLC. Enzymatic hydrolysis and HPLC analysis confirmed the presence of this adduct in the oligomers.

  10. Molecular Modeling of the Major DNA Adduct Formed from Food Mutagen Ochratoxin A in NarI Two-Base Deletion Duplexes: Impact of Sequence Context and Adduct Ionization on Conformational Preference and Mutagenicity.

    Science.gov (United States)

    Kathuria, Preetleen; Sharma, Purshotam; Manderville, Richard A; Wetmore, Stacey D

    2017-08-21

    Exposure to ochratoxin A (OTA), a possible human carcinogen, leads to many different DNA mutations. As a first step toward understanding the structural basis of OTA-induced mutagenicity, the present work uses a robust computational approach and a slipped mutagenic intermediate model previously studied for C8-dG aromatic amine adducts to analyze the conformational features of postreplication two-base deletion DNA duplexes containing OT-dG, the major OTA lesion at the C8 position of guanine. Specifically, a total of 960 ns of molecular dynamics simulations (excluding trial simulations) were carried out on four OT-dG ionization states in three sequence contexts within oligomers containing the NarI recognition sequence, a known hotspot for deletion mutations induced by related adducts formed from known carcinogens. Our results indicate that the structural properties and relative stability of the competing "major groove" and "stacked" conformations of OTA adducted two-base deletion duplexes depend on both the OTA ionization state and the sequence context, mainly due to conformation-dependent deviations in discrete local (hydrogen-bonding and stacking) interactions at the lesion site, as well as DNA bending. When the structural characteristics of the OT-dG adducted two-base deletion duplexes are compared to those associated with previously studied C8-dG adducts, a greater understanding of the effects of the nucleobase-carcinogen linkage, and size of the carcinogenic moiety on the conformational preferences of damaged DNA is obtained. Most importantly, our work predicts key structural features for OT-dG-adducted deletion DNA duplexes, which in turn allow us to develop hypotheses regarding OT-dG replication outcomes. Thus, our computational results are valuable for the design and interpretation of future biochemical studies on the potentially carcinogenic OT-dG lesion.

  11. Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother-child study (NewGeneris).

    Science.gov (United States)

    Pedersen, Marie; Mendez, Michelle A; Schoket, Bernadette; Godschalk, Roger W; Espinosa, Ana; Landström, Anette; Villanueva, Cristina M; Merlo, Domenico F; Fthenou, Eleni; Gracia-Lavedan, Esther; van Schooten, Frederik-J; Hoek, Gerard; Brunborg, Gunnar; Meltzer, Helle M; Alexander, Jan; Nielsen, Jeanette K; Sunyer, Jordi; Wright, John; Kovács, Katalin; de Hoogh, Kees; Gutzkow, Kristine B; Hardie, Laura J; Chatzi, Leda; Knudsen, Lisbeth E; Anna, Lívia; Ketzel, Matthias; Haugen, Margaretha; Botsivali, Maria; Nieuwenhuijsen, Mark J; Cirach, Marta; Toledano, Mireille B; Smith, Rachel B; Fleming, Sarah; Agramunt, Silvia; Kyrtopoulos, Soterios A; Lukács, Viktória; Kleinjans, Jos C; Segerbäck, Dan; Kogevinas, Manolis

    2015-04-01

    Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk. We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates. Pregnant women from Greece, Spain, England, Denmark, and Norway were recruited in 2006-2010. Cord blood bulky DNA adduct levels were measured by the 32P-postlabeling technique (n = 511). Diet and maternal characteristics were assessed via questionnaires. Modeled exposures to air pollutants and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population. Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p < 0.001]. Residence in southern European countries, higher maternal body mass index, delivery by cesarean section, male infant sex, low maternal intake of fruits rich in vitamin C, high intake of dairy products, and low adherence to healthy diet score were statistically significantly associated with higher adduct levels in adjusted models. Exposure to fine particulate matter and nitrogen dioxide was associated with significantly higher adducts in the Danish subsample only. Overall, the pooled results for THMs in water show no evidence of association with adduct levels; however, there are country-specific differences in results with a suggestion of an association in England. These findings suggest that a combination of factors, including unknown country-specific factors, influence the bulky DNA adduct levels in neonates.

  12. Miscoding properties of 1,N{sup 6}-ethanoadenine, a DNA adduct derived from reaction with antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea

    Energy Technology Data Exchange (ETDEWEB)

    Hang, Bo; Guliaev, Anton B.; Chenna, Ahmed; Singer, B.

    2003-03-05

    1,N{sup 6}-Ethanoadenine (EA) is an exocyclic adduct formed from DNA reaction with the antitumor agent, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). To understand the role of this adduct in the mechanism of mutagenicity or carcinogenicity by BCNU, an oligonucleotide with a site-specific EA was synthesized using phosphoramidite chemistry. We now report the in vitro miscoding properties of EA in translesion DNA synthesis catalyzed by mammalian DNA polymerases (pols) {alpha}, {beta}, {eta} and {iota}. These data were also compared with those obtained for the structurally related exocyclic adduct, 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using a primer extension assay, both pols {alpha} and {beta} were primarily blocked by EA or {var_epsilon}A with very minor extension. Pol {eta} a member of the Y family of polymerases, was capable of catalyzing a significant amount of bypass across both adducts. Pol {eta} incorporated all four nucleotides opposite EA and {var_epsilon}A, but with differential preferences and mainly in an error-prone manner. Human pol {iota}, a paralog of human pol {eta}, was blocked by both adducts with a very small amount of synthesis past {var_epsilon}A. It incorporated C and, to a much lesser extent, T, opposite either adduct. In addition, the presence of an A adduct, e.g. {var_epsilon}A, could affect the specificity of pol {iota} toward the template T immediately 3 feet to the adduct. In conclusion, the four polymerases assayed on templates containing an EA or {var_epsilon}A showed differential bypass capacity and nucleotide incorporation specificity, with the two adducts not completely identical in influencing these properties. Although there was a measurable extent of error-free nucleotide incorporation, all these polymerases primarily misincorporated opposite EA, indicating that the adduct, similar to {var_epsilon}A, is a miscoding lesion.

  13. Environmental, Dietary, Maternal, and Fetal Predictors of Bulky DNA Adducts in Cord Blood: A European Mother–Child Study (NewGeneris)

    Science.gov (United States)

    Mendez, Michelle A.; Schoket, Bernadette; Godschalk, Roger W.; Espinosa, Ana; Landström, Anette; Villanueva, Cristina M.; Merlo, Domenico F.; Fthenou, Eleni; Gracia-Lavedan, Esther; van Schooten, Frederik-J.; Hoek, Gerard; Brunborg, Gunnar; Meltzer, Helle M.; Alexander, Jan; Nielsen, Jeanette K.; Sunyer, Jordi; Wright, John; Kovács, Katalin; de Hoogh, Kees; Gutzkow, Kristine B.; Hardie, Laura J.; Chatzi, Leda; Knudsen, Lisbeth E.; Anna, Lívia; Ketzel, Matthias; Haugen, Margaretha; Botsivali, Maria; Nieuwenhuijsen, Mark J.; Cirach, Marta; Toledano, Mireille B.; Smith, Rachel B.; Fleming, Sarah; Agramunt, Silvia; Kyrtopoulos, Soterios A.; Lukács, Viktória; Kleinjans, Jos C.; Segerbäck, Dan; Kogevinas, Manolis

    2015-01-01

    Background: Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk. Objective: We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates. Methods: Pregnant women from Greece, Spain, England, Denmark, and Norway were recruited in 2006–2010. Cord blood bulky DNA adduct levels were measured by the 32P-postlabeling technique (n = 511). Diet and maternal characteristics were assessed via questionnaires. Modeled exposures to air pollutants and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population. Results: Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p Alexander J, Nielsen JK, Sunyer J, Wright J, Kovács K, de Hoogh K, Gutzkow KB, Hardie LJ, Chatzi L, Knudsen LE, Anna L, Ketzel M, Haugen M, Botsivali M, Nieuwenhuijsen MJ, Cirach M, Toledano MB, Smith RB, Fleming S, Agramunt S, Kyrtopoulos SA, Lukács V, Kleinjans JC, Segerbäck D, Kogevinas M. 2015. Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother–child study (NewGeneris). Environ Health Perspect 123:374–380; http://dx.doi.org/10.1289/ehp.1408613 PMID:25626179

  14. Bulky dna adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother-child study (NewGeneris).

    Science.gov (United States)

    Pedersen, Marie; Schoket, Bernadette; Godschalk, Roger W; Wright, John; von Stedingk, Hans; Törnqvist, Margareta; Sunyer, Jordi; Nielsen, Jeanette K; Merlo, Domenico F; Mendez, Michelle A; Meltzer, Helle M; Lukács, Viktória; Landström, Anette; Kyrtopoulos, Soterios A; Kovács, Katalin; Knudsen, Lisbeth E; Haugen, Margaretha; Hardie, Laura J; Gützkow, Kristine B; Fleming, Sarah; Fthenou, Eleni; Farmer, Peter B; Espinosa, Aina; Chatzi, Leda; Brunborg, Gunnar; Brady, Nigel J; Botsivali, Maria; Arab, Khelifa; Anna, Lívia; Alexander, Jan; Agramunt, Silvia; Kleinjans, Jos C; Segerbäck, Dan; Kogevinas, Manolis

    2013-10-01

    Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs. We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy. Pregnant women from Denmark, England, Greece, Norway, and Spain were recruited in 2006-2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires. Adduct levels in maternal and cord blood samples were similar and positively correlated (median, 12.1 vs. 11.4 adducts in 108 nucleotides; Spearman rank correlation coefficient = 0.66, p < 0.001). Cord blood adduct levels were negatively associated with birth weight, with an estimated difference in mean birth weight of -129 g (95% CI: -233, -25 g) for infants in the highest versus lowest tertile of adducts. The negative association with birth weight was limited to births in Norway, Denmark, and England, the countries with the lowest adduct levels, and was more pronounced in births to mothers with low intake of fruits and vegetables (-248 g; 95% CI: -405, -92 g) compared with those with high intake (-58 g; 95% CI: -206, 90 g). Maternal exposure to genotoxic agents that induce the formation of bulky DNA adducts may affect intrauterine growth. Maternal fruit and vegetable consumption may be protective.

  15. Recent developments in DNA adduct analysis by mass spectrometry: a tool for exposure biomonitoring and identification of hazard for environmental pollutants.

    Science.gov (United States)

    Gavina, Jennilee M A; Yao, Chunhe; Feng, Yong-Lai

    2014-12-01

    DNA adducts represent an important category of biomarkers for detection and exposure surveillance of potential carcinogenic and genotoxic chemicals in the environment. Sensitive and specific analytical methods are required to detect and differentiate low levels of adducts from native DNA from in vivo exposure. In addition to biomonitoring of environmental pollutants, analytical methods have been developed for structural identification of adducts which provides fundamental information for determining the toxic pathway of hazardous chemicals. In order to achieve the required sensitivity, mass spectrometry has been increasingly utilized to quantify adducts at low levels as well as to obtain structural information. Furthermore, separation techniques such as chromatography and capillary electrophoresis can be coupled to mass spectrometry to increase the selectivity. This review will provide an overview of advances in detection of adducted and modified DNA by mass spectrometry with a focus on the analysis of nucleosides since 2007. Instrument advances, sample and instrument considerations, and recent applications will be summarized in the context of hazard assessment. Finally, advances in biomonitoring applying mass spectrometry will be highlighted. Most importantly, the usefulness of DNA adducts measurement and detection will be comprehensively discussed as a tool for assessment of in vitro and in vivo exposure to environmental pollutants. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  16. Tamoxifen Forms DNA Adducts In Human Colon After Administration Of A Single [14C]-Labeled Therapeutic Dose.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K; Tompkins, E M; Boocock, D J; Martin, E A; Farmer, P B; Turteltaub, K W; Ubick, E; Hemingway, D; Horner-Glister, E; White, I H

    2007-05-23

    Tamoxifen is widely prescribed for the treatment of breast cancer and is also licensed in the U.S. for the prevention of this disease. However, tamoxifen therapy is associated with an increased occurrence of endometrial cancer in women and there is also evidence that it may elevate the risk of colorectal cancer. The underlying mechanisms responsible for tamoxifen-induced carcinogenesis in women have not yet been elucidated but much interest has focussed on the role of DNA adduct formation. We investigated the propensity of tamoxifen to bind irreversibly to colorectal DNA when given to ten women as a single [{sup 14}C]-labeled therapeutic (20 mg) dose, {approx}18 h prior to undergoing colon resections. Using the sensitive technique of accelerator mass spectrometry, coupled with HPLC separation of enzymatically digested DNA, a peak corresponding to authentic dG-N{sup 2}-tamoxifen adduct was detected in samples from three patients, at levels ranging from 1-7 adducts/10{sup 9} nucleotides. No [{sup 14}C]-radiolabel associated with tamoxifen or its major metabolites was detected. The presence of detectable CYP3A4 protein in all colon samples suggests this tissue has the potential to activate tamoxifen to {alpha}-hydroxytamoxifen, in addition to that occurring in the systemic circulation, and direct interaction of this metabolite with DNA could account for the binding observed. Although the level of tamoxifeninduced damage displayed a degree of inter-individual variability, when present it was {approx}10-100 times higher than that reported for other suspect human colon carcinogens such as PhIP. These findings provide a mechanistic basis through which tamoxifen could increase the incidence of colon cancers in women.

  17. Punicalagin and Ellagic Acid Demonstrate Antimutagenic Activity and Inhibition of Benzo[a]pyrene Induced DNA Adducts

    Directory of Open Access Journals (Sweden)

    Maryam Zahin

    2014-01-01

    Full Text Available Punicalagin (PC is an ellagitannin found in the fruit peel of Punica granatum. We have demonstrated antioxidant and antigenotoxic properties of Punica granatum and showed that PC and ellagic acid (EA are its major constituents. In this study, we demonstrate the antimutagenic potential, inhibition of BP-induced DNA damage, and antiproliferative activity of PC and EA. Incubation of BP with rat liver microsomes, appropriate cofactors, and DNA in the presence of vehicle or PC and EA showed significant inhibition of the resultant DNA adducts, with essentially complete inhibition (97% at 40 μM by PC and 77% inhibition by EA. Antimutagenicity was tested by Ames test. PC and EA dose-dependently and markedly antagonized the effect of tested mutagens, sodium azide, methyl methanesulfonate, benzo[a]pyrene, and 2-aminoflourine, with maximum inhibition of mutagenicity up to 90 percent. Almost all the doses tested (50–500 μM exhibited significant antimutagenicity. A profound antiproliferative effect on human lung cancer cells was also shown with PC and EA. Together, our data show that PC and EA are pomegranate bioactives responsible for inhibition of BP-induced DNA adducts and strong antimutagenic, antiproliferative activities. However, these compounds are to be evaluated in suitable animal model to assess their therapeutic efficacy against cancer.

  18. Punicalagin and ellagic acid demonstrate antimutagenic activity and inhibition of benzo[a]pyrene induced DNA adducts.

    Science.gov (United States)

    Zahin, Maryam; Ahmad, Iqbal; Gupta, Ramesh C; Aqil, Farrukh

    2014-01-01

    Punicalagin (PC) is an ellagitannin found in the fruit peel of Punica granatum. We have demonstrated antioxidant and antigenotoxic properties of Punica granatum and showed that PC and ellagic acid (EA) are its major constituents. In this study, we demonstrate the antimutagenic potential, inhibition of BP-induced DNA damage, and antiproliferative activity of PC and EA. Incubation of BP with rat liver microsomes, appropriate cofactors, and DNA in the presence of vehicle or PC and EA showed significant inhibition of the resultant DNA adducts, with essentially complete inhibition (97%) at 40 μ M by PC and 77% inhibition by EA. Antimutagenicity was tested by Ames test. PC and EA dose-dependently and markedly antagonized the effect of tested mutagens, sodium azide, methyl methanesulfonate, benzo[a]pyrene, and 2-aminoflourine, with maximum inhibition of mutagenicity up to 90 percent. Almost all the doses tested (50-500 μ M) exhibited significant antimutagenicity. A profound antiproliferative effect on human lung cancer cells was also shown with PC and EA. Together, our data show that PC and EA are pomegranate bioactives responsible for inhibition of BP-induced DNA adducts and strong antimutagenic, antiproliferative activities. However, these compounds are to be evaluated in suitable animal model to assess their therapeutic efficacy against cancer.

  19. Dose-dependent reduction of 3,2'-dimethyl-4-aminobiphenyl-derived DNA adducts in colon and liver of rats administered celecoxib

    Energy Technology Data Exchange (ETDEWEB)

    Ravoori, Srivani [James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Feng Yi; Neale, Jason R. [James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Jeyabalan, Jeyaprakash [James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Srinivasan, Cidambi [Department of Statistics, University of Kentucky, Lexington, KY 40502 (United States); Hein, David W. [James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Gupta, Ramesh C. [James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States)], E-mail: rcgupta@louisville.edu

    2008-02-01

    Colon cancer is second leading cause of cancer-related deaths in Western countries. Diet and smoking, which contain aromatic and heterocyclic amines, are major risk factors for colon cancer. Colorectal cancers have a natural history of long latency and therefore provide ample opportunities for effective chemoprevention. 3,2'-Dimethyl-4-aminobiphenyl (DMABP) is an experimental aromatic amine that causes cancer in rat colon and serves as an experimental model for arylamine and heterocyclic amine mutagens derived from diet and smoking. In this study, we investigated the effects of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor on DMABP-induced DNA adduct formation in rat liver and colon. Male F-344 rats (5-week old) were provided free access to modified AIN-76A rat chow containing 0 (control), 500, 1000, or 1500 ppm celecoxib. Two weeks later, the rats received a subcutaneous injection of 100 mg/kg DMABP in peanut oil. Two days after DMABP treatment, the rats were killed and DMABP-derived adducts were analyzed in colon and liver DNA by butanol extraction-mediated {sup 32}P-postlabeling. Two major DNA adducts, identified as dG-C8-DMABP and dG-N{sup 2}-DMABP, were detected in liver and colon of rats treated with DMABP. These DNA adducts were diminished approximately 35-40% with 500 ppm and 65-70% with 1,000 ppm celecoxib. In the colon, no further decline in DNA adducts was observed at 1500 ppm. The same DMABP-DNA adducts also were detected in the liver and were also diminished by celecoxib treatment. The reduction in DMABP-DNA adduct levels in celecoxib-treated animals provides further support for celecoxib as a chemopreventive agent for colorectal cancer.

  20. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  1. Characterization of Thioether-Linked Protein Adducts of DNA Using a Raney-Ni Mediated Desulfurization Method and Liquid Chromatography-Electrospray-Tandem Mass Spectrometry

    Science.gov (United States)

    Chowdhury, Goutam; Guengerich, F. Peter

    2015-01-01

    This unit contains a complete procedure for the detection and structural characterization of DNA protein crosslinks (DPCs). The procedure also describes an approach for the quantitation of the various structurally distinct DPCs. Although various methods have been described in the literature for labile DPCs, characterization of non-labile adducts remain a challenge. Here we present a novel approach for characterization of both labile and non-labile adducts by the use of a combination of chemical, enzymatic, and mass spectrometric approaches. A Raney Ni-catalyzed reductive desulfurization method was used for removal of the bulky peptide adducts, enzymatic digestion was used to digest the protein to smaller peptides and DNA to nucleosides, and finally LC-ESI-tandem mass spectrometry (MS) was utilized for detection and characterization of nucleoside adducts. PMID:25754888

  2. Bulky DNA Adducts in Cord Blood, Maternal Fruit-and-Vegetable Consumption, and Birth Weight in a European Mother-Child Study (NewGeneris)

    DEFF Research Database (Denmark)

    Pedersen, Marie; Schoket, Bernadette; Godschalk, Roger W

    2013-01-01

    with those with high intake (-58 g; 95% CI: -206, 90 g)Conclusions: Maternal exposure to genotoxic agents that induce the formation of bulky DNA adducts may affect intrauterine growth. Maternal fruit and vegetable consumption may be protective.Citation: Pedersen M, Schoket B, Godschalk RW, Wright J, von...... to several genotoxic agents including PAHs.Objectives: We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy.Methods: Pregnant women from Denmark, England......, Greece, Norway, and Spain were recruited in 2006-2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires.Results: Adduct levels in maternal and cord blood samples were similar...

  3. The role of reactive oxygen species (ROS and cytochrome P-450 2E1 in the generation of carcinogenic etheno-DNA adducts

    Directory of Open Access Journals (Sweden)

    Kirsten Linhart

    2014-01-01

    Full Text Available Exocyclic etheno-DNA adducts are mutagenic and carcinogenic and are formed by the reaction of lipidperoxidation (LPO products such as 4-hydoxynonenal or malondialdehyde with DNA bases. LPO products are generated either via inflammation driven oxidative stress or via the induction of cytochrome P-450 2E1 (CYP2E1. In the liver CYP2E1 is induced by various compounds including free fatty acids, acetone and ethanol. Increased levels of CYP2E1 and thus, oxidative stress are observed in the liver of patients with non-alcoholic steatohepatitis (NASH as well as in the chronic alcoholic. In addition, chronic ethanol ingestion also increases CYP2E1 in the mucosa of the oesophagus and colon. In all these tissues CYP2E1 correlates significantly with the levels of carcinogenic etheno-DNA adducts. In contrast, in patients with non-alcoholic steatohepatitis (NASH hepatic etheno-DNA adducts do not correlate with CYP2E1 indicating that in NASH etheno-DNA adducts formation is predominately driven by inflammation rather than by CYP2E1 induction. Since etheno-DNA adducts are strong mutagens producing various types of base pair substitution mutations as well as other types of genetic damage, it is strongly believed that they are involved in ethanol mediated carcinogenesis primarily driven by the induction of CYP2E1.

  4. Complex relationships between occupation, environment, DNA adducts, genetic polymorphisms and bladder cancer in a case-control study using a structural equation modeling.

    Directory of Open Access Journals (Sweden)

    Stefano Porru

    Full Text Available DNA adducts are considered an integrate measure of carcinogen exposure and the initial step of carcinogenesis. Their levels in more accessible peripheral blood lymphocytes (PBLs mirror that in the bladder tissue. In this study we explore whether the formation of PBL DNA adducts may be associated with bladder cancer (BC risk, and how this relationship is modulated by genetic polymorphisms, environmental and occupational risk factors for BC. These complex interrelationships, including direct and indirect effects of each variable, were appraised using the structural equation modeling (SEM analysis. Within the framework of a hospital-based case/control study, study population included 199 BC cases and 213 non-cancer controls, all Caucasian males. Data were collected on lifetime smoking, coffee drinking, dietary habits and lifetime occupation, with particular reference to exposure to aromatic amines (AAs and polycyclic aromatic hydrocarbons (PAHs. No indirect paths were found, disproving hypothesis on association between PBL DNA adducts and BC risk. DNA adducts were instead positively associated with occupational cumulative exposure to AAs (p = 0.028, whereas XRCC1 Arg 399 (p<0.006 was related with a decreased adduct levels, but with no impact on BC risk. Previous findings on increased BC risk by packyears (p<0.001, coffee (p<0.001, cumulative AAs exposure (p = 0.041 and MnSOD (p = 0.009 and a decreased risk by MPO (p<0.008 were also confirmed by SEM analysis. Our results for the first time make evident an association between occupational cumulative exposure to AAs with DNA adducts and BC risk, strengthening the central role of AAs in bladder carcinogenesis. However the lack of an association between PBL DNA adducts and BC risk advises that these snapshot measurements are not representative of relevant exposures. This would envisage new scenarios for biomarker discovery and new challenges such as repeated measurements at different

  5. Metabolomic profiling unravels DNA adducts in human breast that are formed from peroxidase mediated activation of estrogens to quinone methides.

    Directory of Open Access Journals (Sweden)

    Nilesh W Gaikwad

    Full Text Available Currently there are three major hypotheses that have been proposed for estrogen induced carcinogenicity, however exact etiology remains unknown. Based on the chemical logic, studies were undertaken to investigate if estrogens could generate quinone methides in an oxidative environment which then could cause DNA damage in humans. In presence of MnO2 estrogens were oxidized to quinone methides. Surprisingly quinone methides were found to be stable with t1/2 of 20.8 and 4.5 min respectively. Incubation of estrogens with lactoperoxidase (LPO and H2O2 resulted in formation of respective quinone methides (E1(E2-QM. Subsequent addition of adenine to the assay mixture lead to trapping of E1(E2-QM, resulting in formation of adenine adducts of estrogens, E1(E2-9-N-Ade. Targeted ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS based metabolomic analysis of the breast tissue extracts showed the presence of adenine adducts of estrogens, E1(E2-9-N-Ade, along with other estrogen related metabolites. Identity of E1(E2-N-Ade in LPO assay extracts and breast tissue extracts were confirmed by comparing them to pure synthesized E1(E2-9-N-Ade standards. From these results, it is evident that peroxidase enzymes or peroxidase-like activity in human breast tissue could oxidize estrogens to electrophilic and stable quinone methides in a single step that covalently bind to DNA to form adducts. The error prone repair of the damaged DNA can result in mutation of critical genes and subsequently cancer. This article reports evidence for hitherto unknown estrogen metabolic pathway in human breast, catalyzed by peroxidase, which could initiate cancer.

  6. Bulky DNA Adducts in Cord Blood, Maternal Fruit-and-Vegetable Consumption, and Birth Weight in a European Mother–Child Study (NewGeneris)

    Science.gov (United States)

    Schoket, Bernadette; Godschalk, Roger W.; Wright, John; von Stedingk, Hans; Törnqvist, Margareta; Sunyer, Jordi; Nielsen, Jeanette K.; Merlo, Domenico F.; Mendez, Michelle A.; Meltzer, Helle M.; Lukács, Viktória; Landström, Anette; Kyrtopoulos, Soterios A.; Kovács, Katalin; Knudsen, Lisbeth E.; Haugen, Margaretha; Hardie, Laura J.; Gützkow, Kristine B.; Fleming, Sarah; Fthenou, Eleni; Farmer, Peter B.; Espinosa, Aina; Chatzi, Leda; Brunborg, Gunnar; Brady, Nigel J.; Botsivali, Maria; Arab, Khelifa; Anna, Lívia; Alexander, Jan; Agramunt, Silvia; Kleinjans, Jos C.; Segerbäck, Dan; Kogevinas, Manolis

    2013-01-01

    Background: Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs. Objectives: We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy. Methods: Pregnant women from Denmark, England, Greece, Norway, and Spain were recruited in 2006–2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires. Results: Adduct levels in maternal and cord blood samples were similar and positively correlated (median, 12.1 vs. 11.4 adducts in 108 nucleotides; Spearman rank correlation coefficient = 0.66, p Fleming S, Fthenou E, Farmer PB, Espinosa A, Chatzi L, Brunborg G, Brady NJ, Botsivali M, Arab K, Anna L, Alexander J, Agramunt S, Kleinjans JC, Segerbäck D, Kogevinas M. 2013. Bulky DNA adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother–child study (NewGeneris). Environ Health Perspect 121:1200–1206; http://dx.doi.org/10.1289/ehp.1206333 PMID:23906905

  7. Detection and quantitation of benzo(a)pyrene-DNA adducts in brain and liver tissues of Beluga whales (Delphinapterus leucas) from the St. Lawrence and Mackenzie Estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Shugart, L.R.

    1988-01-01

    It should be noted that there are few analytical techniques available for the detection and quantitation of chemical adducts in the DNA of living organisms. The reasons for this are: the analytical technique often has to accommodate the unique chemical and/or physical properties of the individual chemical or its metabolite; the percentage of total chemical that becomes most of the parent compound is usually detoxified and excreted; not all adducts that form between the genotoxic agent and DNA are stable or are involved in the development of subsequent deleterious events in the organism; and the amount of DNA available for analysis is often quite limited. 16 refs., 1 tab.

  8. Effectiveness of human cytochrome P450 3A4 present in liposomal and microsomal nanoparticles in formation of covalent DNA adducts by ellipticine.

    Science.gov (United States)

    Sulc, Miroslav; Mrizova, Iveta; Cerna, Tereza; Frei, Eva; Eckschlager, Tomas; Adam, Vojtech; Kopeckova, Katerina; Stiborova, Marie

    2016-12-18

    Ellipticine is an anticancer agent that functions through multiple mechanisms participating in cell cycle arrest and initiation of apoptosis. This drug forms covalent DNA adducts after its enzymatic activation with cytochrome P450 (CYP), which is one of the most important ellipticine DNA-damaging mechanisms of its cytotoxic effects. The improvements of cancer treatment are the major challenge in oncology research. Nanotransporters (nanoparticles) are promising approaches to target tumor cells, frequently leading to improve drug therapeutic index. Ellipticine has already been prepared in nanoparticle forms. However, since its anticancer efficiency depends on the CYP3A4-mediated metabolism in cancer cells, the aim of our research is to develop nanoparticles containing this enzyme that can be transported to tumor cells, thereby potentiating ellipticine cytotoxicity. The CYP3A4 enzyme encapsulated into two nanoparticle forms, liposomes and microsomes, was tested to activate ellipticine to its reactive species forming covalent DNA adducts. Ellipticine-derived DNA adducts were determined by the 32P-postlabeling method. The CYP3A4 enzyme both in the liposome and microsome nanoparticle forms was efficient to activate ellipticine to species forming DNA adducts. Two DNA adducts, which are formed from ellipticine metabolites 12-hydroxy- and 13-hydroxyellipticine generated by its oxidation by CYP3A4, were formed by both CYP3A4 nanoparticle systems. A higher effectiveness of CYP3A4 in microsomal than in liposomal nanoparticles to form ellipticine-DNA adducts was found. Further testing in a suitable cancer cell model is encouraged to investigate whether the DNA-damaging effects of ellipticine after its activation by CYP3A4 nanoparticle forms are appropriate for active targeting of this enzyme to specific cancer cells.

  9. The carcinogen 1-methylpyrene forms benzylic DNA adducts in mouse and rat tissues in vivo via a reactive sulphuric acid ester.

    Science.gov (United States)

    Bendadani, Carolin; Meinl, Walter; Monien, Bernhard H; Dobbernack, Gisela; Glatt, Hansruedi

    2014-03-01

    The common polycyclic aromatic hydrocarbon 1-methylpyrene is hepatocarcinogenic in the newborn mouse assay. In vitro studies showed that it is metabolically activated via benzylic hydroxylation and sulphation to a reactive ester, which forms benzylic DNA adducts, N(2)-(1-methylpyrenyl)-2'-deoxyguanosine (MPdG) and N(6)-(1-methylpyrenyl)-2'-deoxyadenosine (MPdA). Formation of these adducts was also observed in animals treated with the metabolites, 1-hydroxymethylpyrene and 1-sulphooxymethylpyrene (1-SMP), whereas corresponding data are missing for 1-methylpyrene. In the present study, we treated mice with 1-methylpyrene and subsequently analysed blood serum for the presence of the reactive metabolite 1-SMP and tissue DNA for the presence of MPdG and MPdA adducts. We used wild-type mice and a mouse line transgenic for human sulphotransferases (SULT) 1A1 and 1A2, males and females. All analyses were conducted using ultra-performance liquid chromatography coupled with tandem mass spectrometry, for the adducts with isotope-labelled internal standards. 1-SMP was detected in all treated animals. Its serum level was higher in transgenic mice than in the wild-type (p < 0.001). Likewise, both adducts were detected in liver, kidney and lung DNA of all exposed animals. The transgene significantly enhanced the level of each adduct in each tissue of both sexes (p < 0.01-0.001). Adduct levels were highest in the liver, the target tissue of carcinogenesis, in each animal model used. MPdG and MPdA adducts were also observed in rats treated with 1-methylpyrene. Our findings corroborate the hypothesis that 1-SMP is indeed the ultimate carcinogen of 1-methylpyrene and that human SULT are able to mediate the terminal activation in vivo.

  10. Structure and mechanism of error-free replication past the major benzo[a]pyrene adduct by human DNA polymerase κ.

    Science.gov (United States)

    Jha, Vikash; Bian, Chuanbing; Xing, Guangxin; Ling, Hong

    2016-06-02

    Benzo[a]pyrene (BP) is a well-known and frequently encountered carcinogen which generates a bulky DNA adduct (+)-trans-10S-BP-N(2)-dG (BP-dG) in cells. DNA polymerase kappa (polκ) is the only known Y-family polymerase that bypasses BP-dG accurately and thus protects cells from genotoxic BP. Here, we report the structures of human polκ in complex with DNA containing either a normal guanine (G) base or a BP-dG adduct at the active site and a correct deoxycytidine. The structures and supporting biochemical data reveal a unique mechanism for accurate replication by translesion synthesis past the major bulky adduct. The active site of polκ opens at the minor groove side of the DNA substrate to accommodate the bulky BP-dG that is attached there. More importantly, polκ stabilizes the lesion DNA substrate in the same active conformation as for regular B-form DNA substrates and the bulky BPDE ring in a 5' end pointing conformation. The BP-dG adducted DNA substrate maintains a Watson-Crick (BP-dG:dC) base pair within the active site, governing correct nucleotide insertion opposite the bulky adduct. In addition, polκ's unique N-clasp domain supports the open conformation of the enzyme and the extended conformation of the single-stranded template to allow bypass of the bulky lesion. This work illustrates the first molecular mechanism for how a bulky major adduct is replicated accurately without strand misalignment and mis-insertion. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. A differential mobility spectrometry/mass spectrometry platform for the rapid detection and quantitation of DNA adduct dG-ABP.

    Science.gov (United States)

    Kafle, Amol; Klaene, Joshua; Hall, Adam B; Glick, James; Coy, Stephen L; Vouros, Paul

    2013-07-15

    There is continued interest in exploring new analytical technologies for the detection and quantitation of DNA adducts, biomarkers which provide direct evidence of exposure and genetic damage in cells. With the goal of reducing clean-up steps and improving sample throughput, a Differential Mobility Spectrometry/Mass Spectrometry (DMS/MS) platform has been introduced for adduct analysis. A DMS/MS platform has been utilized for the analysis of dG-ABP, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl (4-ABP). After optimization of the DMS parameters, each sample was analyzed in just 30 s following a simple protein precipitation step of the digested DNA. A detection limit of one modification in 10^6 nucleosides has been achieved using only 2 µg of DNA. A brief comparison (quantitative and qualitative) with liquid chromatography/mass spectrometry is also presented highlighting the advantages of using the DMS/MS method as a high-throughput platform. The data presented demonstrate the successful application of a DMS/MS/MS platform for the rapid quantitation of DNA adducts using, as a model analyte, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Photolysis and thermolysis of platinum(IV) 2,2'-bipyridine complexes lead to identical platinum(II)-DNA adducts.

    Science.gov (United States)

    Loup, Christophe; Tesouro Vallina, Ana; Coppel, Yannick; Létinois, Ulla; Nakabayashi, Yasuo; Meunier, Bernard; Lippert, Bernhard; Pratviel, Geneviève

    2010-10-04

    Two Pt(IV) and two Pt(II) complexes containing a 2,2'-bipyridine ligand were treated with a short DNA oligonucleotide under light irradiation at 37°C or in the dark at 37 and 50°C. Photolysis and thermolysis of the Pt(IV) complexes led to spontaneous reduction of the Pt(IV) to the corresponding Pt(II) complexes and to binding of Pt(II) 2,2'-bipyridine complexes to N7 of guanine. When the reduction product was [Pt(bpy)Cl(2)], formation of bis-oligonucleotide adducts was observed, whereas [Pt(bpy)(MeNH(2))Cl](+) gave monoadducts, with chloride ligands substituted in both cases. Neither in the dark nor under light irradiation was the reductive elimination process of these Pt(IV) complexes accompanied by oxidative DNA damage. This work raises the question of the stability of photoactivatable Pt(IV) complexes toward moderate heating conditions.

  13. Study of DNA adduct 8 hydroxy-2’-deoxyguanosine (8-OHdG) formation through fenton reaction with tert-butylhydroquinone (TBHQ) and butyl hydroxy toluene (BHT)

    Science.gov (United States)

    Handayani, S.; Dani, I. C.; Budiawan; Pakuanisa, D.

    2017-05-01

    The research of DNA adduct formation 8-hydroxy-2’-Deoxyguanosine (8-OHdG) as a biomarker of DNA damage due to oxidative stress was carried out by reacting the DNA base 2’-deoxyguanosine-5’-monophosphate with TBHQ and BHT. The formationof 8-OHdG was carried out in various conditions, at temperature of 37° C and 60° C, pH 7.4 and pH 8.4, within 5 hours of incubation time and in the addition of FeSO4. The formation of DNA adducts profile were analyzed using reversed phase HPLC with UV detector at a wavelength of 254 nm. The results of the study showed that TBHQ and BHT can trigger the formation of 8-OHdG from the reaction of 2’-hydroxy Deoxyguanosine-5’-monophosphate in the presence of Fe (II). Meanwhile, in the addition of hydrogen peroxide, the formation of DNA adducts only occur in the test substance TBHQ. The results showed that the condition of higher temperature at 60°C and pH 8,4 affects the higher formation of DNA adducts.

  14. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuangying, E-mail: shuangying.yu@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Tang, Song, E-mail: song.tang@usask.ca [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Mayer, Gregory D., E-mail: greg.mayer@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Cobb, George P., E-mail: george_cobb@baylor.edu [Department of Environmental Science, Baylor University, One Bear Place #97266, Waco, TX 76798 (United States); Maul, Jonathan D., E-mail: jonathan.maul@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States)

    2015-02-15

    Highlights: • Interactive effects of UVB radiation-pesticide co-exposures were examined in frogs. • Responses included induction of DNA photo-adducts and DNA damage and repair genes. • Elevated DNA adduct levels occurred for co-exposures compared to UVB alone. • One mechanism is that pesticides may alter nuclear excision repair gene expression. - Abstract: Pesticide use and ultraviolet-B (UVB) radiation have both been suggested to adversely affect amphibians; however, little is known about their interactive effects. One potential adverse interaction could involve pesticide-induced dysregulation of DNA repair pathways, resulting in greater numbers of DNA photo-adducts from UVB exposure. In the present study, we investigated the interactive effects of UVB radiation and two common pesticides (endosulfan and α-cypermethrin) on induction of DNA photo-adducts and expression of DNA damage and repair related genes in African clawed frog (Xenopus laevis) embryos. We examined 13 genes that are, collectively, involved in stress defense, cell cycle arrest, nucleotide excision repair (NER), base excision repair, mismatch repair, DNA repair regulation, and apoptosis. We exposed X. laevis embryos to 0, 25, and 50 μg/L endosulfan or 0, 2.5, and 5.0 μg/L α-cypermethrin for 96 h, with environmentally relevant exposures of UVB radiation during the last 7 h of the 96 h exposure. We measured the amount of cyclobutane pyrimidine dimers (CPDs) and mRNA abundance of the 13 genes among treatments including control, pesticide only, UVB only, and UVB and pesticide co-exposures. Each of the co-exposure scenarios resulted in elevated CPD levels compared to UVB exposure alone, suggesting an inhibitory effect of endosulfan and α-cypermethrin on CPD repair. This is attributed to results indicating that α-cypermethrin and endosulfan reduced mRNA abundance of XPA and HR23B, respectively, to levels that may affect the initial recognition of DNA lesions. In contrast, both pesticides

  15. Mutations Induced by Benzo[a]pyrene and Dibenzo[a,l]pyrene in lacI Transgenic B6C3F1 Mouse Lung Result from Stable DNA Adducts

    Science.gov (United States)

    Dibenzo[a,l]pyrene (DB[a,l]P) and benzo[a]pyrene (B[a]P) are carcinogenic polycyclic aromatic hydrocarbons (PAH) that are each capable of forming a variety of covalent adducts with DNA. Some of the DNA adducts formed by these PAHs have been demonstrated to spontaneously depurina...

  16. Ultrasensitive High-Resolution Mass Spectrometric Analysis of a DNA Adduct of the Carcinogen Benzo[a]pyrene in Human Lung.

    Science.gov (United States)

    Villalta, Peter W; Hochalter, J Bradley; Hecht, Stephen S

    2017-12-05

    Benzo[a]pyrene (BaP), an archetypical polycyclic aromatic hydrocarbon, is classified as "carcinogenic to humans" and is ubiquitous in the environment, as evident by the measurable levels of BaP metabolites in virtually all human urine samples examined. BaP carcinogenicity is believed to occur mainly through its covalent modification of DNA, resulting in the formation of BPDE-N2-dG, an adduct formed between deoxyguanosine and a diol epoxide metabolite of BaP, with subsequent mutation of critical growth control genes. In spite of the liquid chromatography-mass spectrometry (LC-MS)-based detection of BPDE-N2-dG in BaP-treated rodents, and indirectly through high-performance liquid chromatography (HPLC)-fluorescence detection of BaP-7,8,9,10-tetraols released from human DNA upon acid hydrolysis, BPDE-N2-dG adducts have rarely if ever been observed directly in human samples using LC-MS techniques, even though sophisticated methodologies have been employed which should have had sufficient sensitivity. With this in mind, we developed a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodology employing high-resolution/accurate mass analysis for detecting ultratrace levels of these adducts. These efforts are directly translatable to the development of sensitive detection of other small molecules using trap-based LC-ESI-MS/MS detection. The developed methodology had a limit of detection (LOD) of 1 amol of BPDE-N2-dG on-column, corresponding to 1 BPDE-N2-dG adduct per 1011 nucleotides (1 adduct per 10 human lung cells) using 40 μg of human lung DNA. To our knowledge, this is the most sensitive DNA adduct quantitation method yet reported, exceeding the sensitivity of the 32P-postlabeling assay (∼1 adduct per 1010 nucleotides). Twenty-nine human lung DNA samples resulted in 20 positive measurements above the LOD, with smoker and nonsmoker DNA containing 3.1 and 1.3 BPDE-N2-dG adducts per 1011 nucleotides, respectively.

  17. DNA Damage in Rheumatoid Arthritis: An Age-Dependent Increase in the Lipid Peroxidation-Derived DNA Adduct, Heptanone-Etheno-2′-Deoxycytidine

    Directory of Open Access Journals (Sweden)

    Masako Ogawa

    2013-01-01

    Full Text Available Objective. To evaluate what types of DNA damages are detected in rheumatoid arthritis (RA. Methods. The DNA adducts such as 8-oxo-hydroxy-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG, 1,N6-etheno-2′-deoxyadenosine (εdA, and heptanone-etheno-2′-deoxycytidine (HεdC in genomic DNAs, derived from whole blood cells from 46 RA patients and 31 healthy controls, were analyzed by high-performance liquid chromatography tandem mass spectrometry, and their levels in RA patients and controls were compared. In addition, correlation between DNA adducts and clinical parameters of RA was analyzed. Results. Compared with controls, the levels of HεdC in RA were significantly higher (P<0.0001 and age dependent (r = 0.43, P < 0.01, while there was no significant difference in 8-oxo-dG and εdA accumulation between RA patients and controls. HεdC levels correlated well with the number of swollen joints (r = 0.57, P < 0.0001 and weakly with the number of tender joints (r = 0.26, P = 0.08 of RA patients, while they did not show a significant association with serological markers such as C-reactive protein and matrix metalloproteinase 3. Conclusion. These findings indicate that HεdC may have some influence on the development of RA and/or its complications.

  18. Non-specificity and synergy at the binding site of the carboplatin-induced DNA adduct via molecular dynamics simulations of the MutSα-DNA recognition complex

    Science.gov (United States)

    Negureanu, Lacramioara; Salsbury, Freddie R

    2013-01-01

    MutSα is the most abundant mismatch binding factor of human DNA mismatch repair (MMR) proteins. MMR maintain genetic stability by recognizing and repairing DNA defects. Failure to accomplish their function may lead to cancer. In addition, MutSα recognizes at least some types of DNA damage making it a target for anticancer agents. Here, complementing scarce experimental data, we report unique hydrogen bonding motifs associated with the recognition of the carboplatin induced DNA damage by MutSα. These data predict that carboplatin and cisplatin induced damaging DNA adducts are recognized by MutSα in a similar manner. Our simulations also indicate that loss of base pairing at the damage site results in (1) non-specific binding and (2) changes in the atomic flexibility at the lesion site and beyond. To further quantify alterations at MutSα-DNA interface in response to damage recognition non-bonding interactions and salt bridges were investigated. These data indicate (1) possible different packing and (2) disruption of the salt bridges at the MutSα-DNA interface in the damaged complex. These findings (1) underscore the general observation of disruptions at the MutSα-DNA interface and (2) highlight the nature of the anticancer effect of the carboplatin agent. The analysis was carried out from atomistic simulations. PMID:23799640

  19. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos.

    Science.gov (United States)

    Yu, Shuangying; Tang, Song; Mayer, Gregory D; Cobb, George P; Maul, Jonathan D

    2015-02-01

    Pesticide use and ultraviolet-B (UVB) radiation have both been suggested to adversely affect amphibians; however, little is known about their interactive effects. One potential adverse interaction could involve pesticide-induced dysregulation of DNA repair pathways, resulting in greater numbers of DNA photo-adducts from UVB exposure. In the present study, we investigated the interactive effects of UVB radiation and two common pesticides (endosulfan and α-cypermethrin) on induction of DNA photo-adducts and expression of DNA damage and repair related genes in African clawed frog (Xenopus laevis) embryos. We examined 13 genes that are, collectively, involved in stress defense, cell cycle arrest, nucleotide excision repair (NER), base excision repair, mismatch repair, DNA repair regulation, and apoptosis. We exposed X. laevis embryos to 0, 25, and 50 μg/L endosulfan or 0, 2.5, and 5.0 μg/L α-cypermethrin for 96 h, with environmentally relevant exposures of UVB radiation during the last 7 h of the 96 h exposure. We measured the amount of cyclobutane pyrimidine dimers (CPDs) and mRNA abundance of the 13 genes among treatments including control, pesticide only, UVB only, and UVB and pesticide co-exposures. Each of the co-exposure scenarios resulted in elevated CPD levels compared to UVB exposure alone, suggesting an inhibitory effect of endosulfan and α-cypermethrin on CPD repair. This is attributed to results indicating that α-cypermethrin and endosulfan reduced mRNA abundance of XPA and HR23B, respectively, to levels that may affect the initial recognition of DNA lesions. In contrast, both pesticides increased transcript abundance of CSA and MUTL. In addition, mRNA abundance of HSP70 and GADD45α were increased by endosulfan and mRNA abundance of XPG was increased by α-cypermethrin. XPC, HR23B, XPG, and GADD45α exhibited elevated mRNA concentrations whereas there was a reduction in MUTL transcript concentrations in UVB-alone treatments. It appeared that even

  20. Urinary Metabolites of the Dietary Carcinogen PhIP are Predictive of Colon DNA Adducts After a Low Dose Exposure in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M; Dingley, K; Nowell, S; Ubick, E; Mulakken, N; Nelson, D; Lang, N; Felton, J; Turteltaub, K

    2006-04-28

    Epidemiologic evidence indicates that exposure to heterocyclic amines (HAs) in the diet is an important risk factor for the development of colon cancer. Well-done cooked meats contain significant levels of HAs which have been shown to cause cancer in laboratory animals. To better understand the mechanisms of HA bioactivation in humans, the most mass abundant HA, 2-amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was used to assess the relationship between PhIP metabolism and DNA adduct formation. Ten human volunteers were administered a dietary relevant dose of [{sup 14}C]PhIP 48-72 h prior to surgery to remove colon tumors. Urine was collected for 24 h after dosing for metabolite analysis, and DNA was extracted from colon tissue and analyzed by accelerator mass spectrometry for DNA adducts. All ten subjects were phenotyped for CYP1A2, NAT2, and SULT1A1 enzyme activity. Twelve PhIP metabolites were detected in the urine samples. The most abundant metabolite in all volunteers was N-hydroxy-PhIP-N{sup 2}-glucuronide. Metabolite levels varied significantly between the volunteers. Interindividual differences in colon DNA adducts levels were observed between each individual. The data showed that individuals with a rapid CYP1A2 phenotype and high levels of urinary N-hydroxy-PhIP-N{sup 2}-glucuronide, had the lowest level of colon PhIP-DNA adducts. This suggests that glucuronidation plays a significant role in detoxifying N-hydroxy-PhIP. The levels of urinary N-hydroxy-PhIP-N{sup 2}-glucuronide were negatively correlated to colon DNA adduct levels. Although it is difficult to make definite conclusions from a small data set, the results from this pilot study have encouraged further investigations using a much larger study group.

  1. Inhibition of HIV-1 reverse transcriptase-catalyzed synthesis by intercalated DNA Benzo[a]Pyrene 7,8-Dihydrodiol-9,10-Epoxide adducts.

    Directory of Open Access Journals (Sweden)

    Parvathi Chary

    Full Text Available To aid in the characterization of the relationship of structure and function for human immunodeficiency virus type-1 reverse transcriptase (HIV-1 RT, this investigation utilized DNAs containing benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE-modified primers and templates as a probe of the architecture of this complex. BPDE lesions that differed in their stereochemistry around the C10 position were covalently linked to N (6-adenine and positioned in either the primer or template strand of a duplex template-primer. HIV-1 RT exhibited a stereoisomer-specific and strand-specific difference in replication when the BPDE-lesion was placed in the template versus the primer strand. When the C10 R-BPDE adduct was positioned in the primer strand in duplex DNA, 5 nucleotides from the 3΄ end of the primer terminus, HIV-1 RT could not fully replicate the template, producing truncated products; this block to further synthesis did not affect rates of dissociation or DNA binding affinity. Additionally, when the adducts were in the same relative position, but located in the template strand, similar truncated products were observed with both the C10 R and C10 S BPDE adducts. These data suggest that the presence of covalently-linked intercalative DNA adducts distant from the active site can lead to termination of DNA synthesis catalyzed by HIV-1 RT.

  2. INDUCTION OF DNA ADDUCTS, TUMORS, AND KI-RAS ONCOGENE MUTATIONS IN STRAIN A/J MOUSE LUNG BY IP. ADMINISTRATION OF DIBENZ[A,H]ANTHRACENE

    Science.gov (United States)

    Induction of DNA adducts, tumors, and Ki-ras oncogene mutations in strain AlJ mouse lung by ip. administration of dibenz[a,h]anthracene Previous studies of polycyclic aromatic hydrocarbon (P AH) induced lung tumors in the strain NJ mouse model system have demonstrated qua...

  3. Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis

    Science.gov (United States)

    Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-B[a]P-7,8-diol-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: 1.] The induction of apurinic sites from r...

  4. Absence of formation of benzo[a]pyrene/DNA adducts in the cuttlefish (Sepia officinalis, Mollusca: Cephalopoda)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, P.G.; Lu, L.J.W.; Salazar, J.J.; Holoubek, V. (Univ. of Texas Medical Branch, Galveston, TX (United States))

    1994-01-01

    Benzo[a]pyrene (B[a]P) injected intramuscularly into the base of the arms of cuttlefish was released continuously from the injection site and removed from the organism. Only a portion of the compound accumulated in the body. Twenty-four hr after its injection, 75% of B[a]P applied in olive oil was removed from the cuttlefish, and 1.2% was found in the body outside the head, in site of injection. If the carcinogen was dissolved in dimethylformamide, the removal of B[a]P was slower, so that only 18% of the injected B[a]P was removed from the organism and 0.36% accumulated in the body outside the head 24 hr after injection. The high level of B[a]P in gills and hemolymph 4 hr after injection and the kinetics of the decrease of its concentration with time indicate that these two organs could be involved in the excretion of B[a]P from the body. The B[a]P/DNA adducts characteristic for vertebrates could not be demonstrated in gills, skin, brain, hepatopancreas, and lymphocytes of the cuttlefish 24 hr after injection. The dose of the carcinogene injected into the cuttlefish was 2-4 times higher than the dose resulting in the formation of a high level of B[a]P/DNA adducts in vertebrates. A different metabolism of B[a]P in the tissue of cephalopods, compared to vertebrates, could be less favorable to the process leading to malignant transformation and could explain the absence from the literature of reports of tumors in cephalopods. 15 refs., 1 fig., 2 tabs.

  5. Evaluation of the metabolic fate of munitions material (TNT & RDX) in plant systems and initial assessment of material interaction with plant genetic material (DNA). Initial assessment of plant DNA adducts as biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, S.D.; Clauss, T.W.; Fellows, R.J.; Cataldo, D.A.

    1995-08-01

    Genetic damage to deoxyribonucleic acid (DNA) has long been suspected of being a fundamental event leading to cancer. A variety of causal factors can result in DNA damage including photodimerization of base pairs, ionizing radiation, specific reaction of DNA with environmental pollutants, and nonspecific oxidative damage caused by the action of highly reactive oxidizing agents produced by metabolism. Because organisms depend on an unadulterated DNA template for reproduction, DNA repair mechanisms are an important defense for maintaining genomic integrity. The objective of this exploratory project was to evaluate the potential for TNT to form DNA adducts in plants. These adducts, if they exist in sufficient quantities, could be potential biomarkers of munitions exposure. The ultimate goal is to develop a simple analytical assay for the determination of blomarkers that is indicative of munitions contamination. DNA repair exists in dynamic equilibrium with DNA damage. Repair mechanisms are capable of keeping DNA damage at remarkably low concentrations provided that the repair capacity is not overwhelmed.

  6. Syntheses of DNA adducts of two heterocyclic amines, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) and 2-amino-9H-pyrido[2,3-b]indole (A alpha C) and identification of DNA adducts in organs from rats dosed with MeA alpha C

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Frandsen, Henrik Lauritz; Pfau, W.

    2004-01-01

    by reaction of the parent amines with acetylated guanine N3-oxide. N-2-OH-MeAalphaC and N-2-OH-AalphaC reacted with calf thymus DNA after addition of acetic anhydride. P-32-postlabelling analysis of modified DNA showed one major adduct co-migrating with N-2-(3',5'-diphospho-2'-deoxyguanosin-8-yl...

  7. Biomarkers for exposure to ambient air pollution--comparison of carcinogen-DNA adduct levels with other exposure markers and markers for oxidative stress

    DEFF Research Database (Denmark)

    Autrup, H; Daneshvar, B; Dragsted, L O

    1999-01-01

    Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts....../10(8) nucleotides) and of 2-amino-apidic semialdehyde (AAS) in plasma proteins (56.7 pmol/mg protein) were observed in bus drivers working in the central part of Copenhagen, Denmark. In contrast, significantly higher levels of AAS in hemoglobin (55.8 pmol/mg protein), malondialdehyde in plasma (0. 96...... nmol/ml plasma), and polycyclic aromatic hydrocarbon (PAH)-albumin adduct (3.38 fmol/ microg albumin) were observed in the suburban group. The biomarker levels in postal workers were similar to the levels in suburban bus drivers. In the combined group of bus drivers and postal workers, negative...

  8. Identification of More Than One Hundred Structurally Unique DNA-Phosphate Adducts Formed During Rat Lung Carcinogenesis by the Tobacco-Specific Nitrosamine 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone.

    Science.gov (United States)

    Ma, Bin; Zarth, Adam T; Carlson, Erik S; Villalta, Peter W; Upadhyaya, Pramod; Stepanov, Irina; Hecht, Stephen S

    2017-11-29

    The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a powerful lung carcinogen in animal models and is considered a causative factor for lung cancer in people who use tobacco products. NNK undergoes metabolic activation - a critical step in its mechanism of carcinogenesis - to an intermediate which reacts with DNA to form pyridyloxobutyl DNA base and phosphate adducts. Another important metabolic pathway of NNK is its conversion to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which similarly forms pyridylhydroxybutyl DNA base adducts that have been characterized previously. In this study, we investigated the potential formation of pyridylhydroxybutyl DNA phosphate adducts. We report the characterization and quantitation of 107 structurally unique pyridylhydroxybutyl DNA phosphate adducts in the lungs of rats treated chronically with a carcinogenic dose of 5 ppm of NNK in their drinking water for up to 70 weeks, by using a novel liquid chromatography-nanoelectrospray ionization-high-resolution tandem mass spectrometry method. Our findings demonstrate that pyridylhydroxybutyl phosphate adducts account for 38-55% and 34-40% of all the measured pyridine-containing DNA adducts in rat lung and liver, respectively, upon treatment with NNK. Some of the pyridylhydroxybutyl DNA phosphate adducts persisted in both tissues for over 70 weeks, suggesting that they could be potential biomarkers of chronic exposure to NNK and NNAL. This study provides comprehensive characterization and relative quantitation of a panel of NNK/NNAL-derived DNA phosphate adducts, thus identifying NNK as the source of the most structurally diverse set of DNA adducts identified to date from any carcinogen. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Genotoxic fungicide methyl thiophanate as an oxidative stressor inducing 8-oxo-7,8-dihydro-2' -deoxyguanosine adducts in DNA and mutagenesis.

    Science.gov (United States)

    Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Singh, Braj R; Arif, Jamal M; Musarrat, Javed

    2010-01-01

    Dimethyl 4,4' -(O-phenylene)bis(3-thioallophanate), commonly known as methyl thiophanate (MT), is a systemic fungicide and suspected carcinogen to humans. In this study, the oxidative potential of this category-III acute toxicant has been ascertained based on its capacity of inducing reactive oxygen species (ROS) and promutagenic 8-oxo-7,8-dihydro-2' -deoxyguanosine (8-oxodG) adducts in DNA. The discernible MT dose-dependent reduction in fluorescence intensity of a cationic dye rhodamine (Rh-123) in human lymphocytes and increased fluorescence intensity of 2',7'-Dichlorodihydro fluorescein diacetate (DCFH-DA) treated cells signifies decreased mitochondrial membrane potential (Delta Psi m) due to intracellular ROS generation. The (32)P-post-labeling assay demonstrated the MT-induced 8-oxodG adduct formation in calf thymus DNA. Thus, it is concluded that MT, as a potent oxidative stressor, produces ROS leading to mitochondrial dysfunction, oxidative DNA damage and mutagenesis.

  10. Immunocytochemical analysis of cisplatin-induced platinum-DNA adducts with double-fluorescence video microscopy

    NARCIS (Netherlands)

    Meijer, C.; Vries, E.G.E. de; Dam, W.A.; Wilkinson, M.H.F.; Hollema, H.; Hoekstra, H.J.; Mulder, N.H.

    To detect low-level DNA platination, a sensitive immunocyto- and histochemical technique was developed using a polyclonal antibody. The antibody GPt, derived after immunization of rabbits with highly platinated DNA and purified with affinity chromatography, detected the main platinum (Pt)-containing

  11. Cockayne syndrome: varied requirement of transcription-coupled nucleotide excision repair for the removal of three structurally different adducts from transcribed DNA.

    Directory of Open Access Journals (Sweden)

    Nataliya Kitsera

    Full Text Available Hereditary defects in the transcription-coupled nucleotide excision repair (TC-NER pathway of damaged DNA cause severe neurodegenerative disease Cockayne syndrome (CS, however the origin and chemical nature of the underlying DNA damage had remained unknown. To find out, to which degree the structural properties of DNA lesions determine the extent of transcription arrest in human CS cells, we performed quantitative host cell reactivation analyses of expression vectors containing various synthetic adducts. We found that a single 3-(deoxyguanosin-N2-yl-2-acetylaminofluorene adduct (dG(N2-AAF constitutes an unsurmountable obstacle to transcription in both CS-A and CS-B cells and is removed exclusively by the CSA- and CSB-dependent pathway. In contrast, contribution of the CS proteins to the removal of two other transcription-blocking DNA lesions - N-(deoxyguanosin-8-yl-2-acetylaminofluorene (dG(C8-AAF and cyclobutane thymine-thymine (TT dimer - is only minor (TT dimer or none (dG(C8-AAF. The unique properties of dG(N2-AAF identify this adduct as a prototype for a new class of DNA lesions that escape the alternative global genome repair and could be critical for the CS pathogenesis.

  12. Determination of polycyclic aromatic hydrocarbons in the urine, benzo(a)pyrene diol epoxide-DNA adducts in lymphocyte DNA, and antibodies to the adducts in sera from coke oven workers exposed to measured amounts of polycyclic aromatic hydrocarbons in the work atmosphere.

    Science.gov (United States)

    Haugen, A; Becher, G; Benestad, C; Vahakangas, K; Trivers, G E; Newman, M J; Harris, C C

    1986-08-01

    Workers in coke oven plants have a higher incidence of lung cancer than the general population. They are exposed to a variety of chemicals, in particular the polycyclic aromatic hydrocarbons (PAH), including benzo(a)pyrene. To evaluate the genotoxic effects of PAH exposure, air samples and urine samples were analyzed for PAH by capillary gas chromatography and high-performance liquid chromatography, respectively. Since benzo(a)pyrene is activated to 7 beta,8 alpha-dihydroxy-(9 alpha,10 alpha)-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE) and binds to DNA, we have used ultrasensitive enzymatic radioimmunoassay and synchronous fluorescence spectrophotometry to measure BPDE-DNA adducts in lymphocyte DNA. The results show that workers were exposed to high concentrations of atmospheric PAH. However, the mean PAH exposure levels are reduced 60% when the workers wore masks during work. When compared to exposure levels, the urinary excretion of PAH was relatively low. Approximately one-third of the workers had detectable putative BPDE-DNA adducts in lymphocytes by ultrasensitive enzymatic radioimmunoassay, and 10% of the samples had emission peaks at 379 nm by synchronous fluorescence spectrophotometry. The four most positive samples were the same in both of the assays. Antibodies to an epitope(s) on BPDE-DNA were found in the sera of approximately one-third of the workers. Detection of DNA adducts and antibodies to these adducts are internal indicators of exposure to benzo(a)pyrene.

  13. DNA adducts from nitroreduction of 2,7-dinitrofluorene, a mammary gland carcinogen, catalyzed by rat liver or mammary gland cytosol.

    Science.gov (United States)

    Ritter, Clare L; Culp, Sandra J; Freeman, James P; Marques, M Matilde; Beland, Frederick A; Malejka-Giganti, Danuta

    2002-04-01

    Nitrofluorenes are mutagenic and carcinogenic environmental pollutants arising chiefly from combustion of fossil fuels. Nitro aromatic compounds undergo nitroreduction to N-hydroxy arylamines that bind to DNA directly or after O-esterification. This study analyzes the DNA binding and adducts from the in vitro nitroreduction of 2,7-dinitrofluorene (2,7-diNF), a potent mammary carcinogen in the rat. Potential adduct(s) of 2,7-diNF was (were) generated by reduction of 2-nitroso-7-NF with ascorbate/H(+) in the presence of calf thymus DNA. The major adduct was characterized by HPLC/ESI/MS and (1)H NMR spectrometry as N-(deoxyguanosin-8-yl)-2-amino-7-NF, and a minor one was determined by HPLC/ESI/MS to be a deoxyadenosine adduct of 2-amino-7-NF. Products from enzymatic nitroreduction were monitored by HPLC and DNA adduct formation by (32)P-postlabeling. Xanthine oxidase/hypoxanthine-catalyzed nitroreduction of 2,7-diNF, 2-nitrofluorene (2-NF), and 1-nitropyrene (1-NP) yielded the respective amines to similar extents (30-50%). However, the level of the major adducts ( approximately 0.15/10(6) nucleotides) from 2-NF [N-(deoxyguanosin-8-yl)-2-aminofluorene] and 2,7-diNF [N-(deoxyguanosin-8-yl)-2-amino-7-NF] was 30 adducts/10(6) nucleotides, levels comparable to those from 1,6-dinitropyrene and 4- or 49-fold greater than the respective levels without acetyl CoA. Recovery of 2-nitroso-7-NF and 2-amino-7-NF from cytosol-catalyzed reduction of 2,7-diNF indicated nitroreduction and an N-hydroxy arylamine intermediate. Likewise, the presence of 2-acetylamino-7-NF indicated that reactivity with acyltransferase(s) was not prevented by the nitro group at C7. These data are consistent with activation of 2,7-diNF via nitroreduction to the N-hydroxy arylamine and acetyl CoA-dependent O-acetylation of the latter to bind to DNA. Enzymatic nitroreduction of 2,7-diNF was greatly enhanced by 9-oxidation. The nitroreduction of either 9-oxo-2,7-diNF or 9-hydroxy-2,7-diNF catalyzed by liver

  14. APE1, the DNA base excision repair protein, regulates the removal of platinum adducts in sensory neuronal cultures by NER

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Suk [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Guo, Chunlu; Thompson, Eric L. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Jiang, Yanlin [Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Kelley, Mark R. [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Vasko, Michael R. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Lee, Suk-Hee, E-mail: slee@iu.edu [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States)

    2015-09-15

    Peripheral neuropathy is one of the major side effects of treatment with the anticancer drug, cisplatin. One proposed mechanism for this neurotoxicity is the formation of platinum adducts in sensory neurons that could contribute to DNA damage. Although this damage is largely repaired by nuclear excision repair (NER), our previous findings suggest that augmenting the base excision repair pathway (BER) by overexpressing the repair protein APE1 protects sensory neurons from cisplatin-induced neurotoxicity. The question remains whether APE1 contributes to the ability of the NER pathway to repair platinum-damage in neuronal cells. To examine this, we manipulated APE1 expression in sensory neuronal cultures and measured Pt-removal after exposure to cisplatin. When neuronal cultures were treated with increasing concentrations of cisplatin for two or three hours, there was a concentration-dependent increase in Pt-damage that peaked at four hours and returned to near baseline levels after 24 h. In cultures where APE1 expression was reduced by ∼80% using siRNA directed at APE1, there was a significant inhibition of Pt-removal over eight hours which was reversed by overexpressing APE1 using a lentiviral construct for human wtAPE1. Overexpressing a mutant APE1 (C65 APE1), which only has DNA repair activity, but not its other significant redox-signaling function, mimicked the effects of wtAPE1. Overexpressing DNA repair activity mutant APE1 (226 + 177APE1), with only redox activity was ineffective suggesting it is the DNA repair function of APE1 and not its redox-signaling, that restores the Pt-damage removal. Together, these data provide the first evidence that a critical BER enzyme, APE1, helps regulate the NER pathway in the repair of cisplatin damage in sensory neurons.

  15. Serum Level of Antibody against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in People Dermally Exposed to PAHs

    Directory of Open Access Journals (Sweden)

    Lenka Borska

    2014-01-01

    Full Text Available Some specific antibodies indicate the presence of antigenic structures on DNA (DNA adducts that can play an important role in the process of mutagenesis and/or carcinogenesis. They indicate the presence of increased genotoxic potential (hazard prior to the formation of disease (primary prevention. The present study was focused on the serum level of benzo[a]pyrene 7,8-diol-9,10-epoxide-DNA adducts antibodies (anti-BPDE-DNA in psoriatic patients (n=55 dermally exposed to different levels of polycyclic aromatic hydrocarbons (PAHs. The general goal of the study was to contribute to better understanding of the value of the assumed biomarker (anti-BPDE-DNA for evaluation of the organism's answer to genotoxic exposure to PAHs. Elevated level of exposure to PAHs resulted in the increased level of anti-BPDE-DNA. However, almost all levels of anti-BPDE-DNA ranged within the field of low values. Both variants of GT (CCT-3% and CCT-5% induced higher expression of anti-BPDE-DNA in the group of nonsmokers. Significant relations between the level of anti-BPDE-DNA and PASI score, total duration of the therapy, or time of UVR exposure were not found. Further studies are needed to reduce interpretation uncertainty of this promising bioindicator.

  16. Mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in colon and liver of Big Blue rats: role of DNA adducts, strand breaks, DNA repair and oxidative stress

    DEFF Research Database (Denmark)

    Moller, P.; Wallin, H.; Vogel, U.

    2002-01-01

    weeks. There were dose-response relationships of DNA adducts (P-32-postlabeling) and DNA strand breaks (comet assay) in colon and liver tissues, with the highest levels of DNA adducts and strand breaks in the colon. There was dose-dependent induction of mutations in both the colon and the liver...... and colon. A lower frequency of mutations in the colon than in the liver could be related to higher expression of DNA repair enzymes in the former.......The contribution of oxidative stress, different types of DNA damage and expression of DNA repair enzymes in colon and liver mutagenesis induced by 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) was investigated in four groups of six Big Blue rats fed diets with 0, 20, 70, and 200 mg IQ/kg for 3...

  17. Highly mutagenic exocyclic DNA adducts are substrates for the human nucleotide incision repair pathway.

    Directory of Open Access Journals (Sweden)

    Paulina Prorok

    Full Text Available BACKGROUND: Oxygen free radicals induce lipid peroxidation (LPO that damages and breaks polyunsaturated fatty acids in cell membranes. LPO-derived aldehydes and hydroxyalkenals react with DNA leading to the formation of etheno(ε-bases including 1,N(6-ethenoadenine (εA and 3,N(4-ethenocytosine (εC. The εA and εC residues are highly mutagenic in mammalian cells and eliminated in the base excision repair (BER pathway and/or by AlkB family proteins in the direct damage reversal process. BER initiated by DNA glycosylases is thought to be the major pathway for the removal of non-bulky endogenous base damage. Alternatively, in the nucleotide incision repair (NIR pathway, the apurinic/apyrimidinic (AP endonucleases can directly incise DNA duplex 5' to a damaged base in a DNA glycosylase-independent manner. METHODOLOGY/PRINCIPAL FINDINGS: Here we have characterized the substrate specificity of human major AP endonuclease 1, APE1, towards εA, εC, thymine glycol (Tg and 7,8-dihydro-8-oxoguanine (8oxoG residues when present in duplex DNA. APE1 cleaves oligonucleotide duplexes containing εA, εC and Tg, but not those containing 8oxoG. Activity depends strongly on sequence context. The apparent kinetic parameters of the reactions suggest that APE1 has a high affinity for DNA containing ε-bases but cleaves DNA duplexes at an extremely slow rate. Consistent with this observation, oligonucleotide duplexes containing an ε-base strongly inhibit AP site nicking activity of APE1 with IC(50 values in the range of 5-10 nM. MALDI-TOF MS analysis of the reaction products demonstrated that APE1-catalyzed cleavage of εA•T and εC•G duplexes generates, as expected, DNA fragments containing 5'-terminal ε-base residue. CONCLUSIONS/SIGNIFICANCE: The fact that ε-bases and Tg in duplex DNA are recognized and cleaved by APE1 in vitro, suggests that NIR may act as a backup pathway to BER to remove a large variety of genotoxic base lesions in human cells.

  18. Phosphate alkylation in different DNA substrates: the role of local DNA sequence and electrophile character in determining the nonrandom nature of phosphotriester adduct formation.

    Science.gov (United States)

    Le Pla, Rachel C; Bowman, Karen J; Farmer, Peter B; Jones, George D D

    2006-03-01

    DNA phosphate oxygens are sites for alkylation leading to DNA phosphotriester adduct (PTE) formation. Previously, we have reported that the manifestation of PTEs was nonrandom in mouse liver DNA treated in vivo [Guichard et al. (2000) Cancer Res. 60, 1276-1282], and while further studies revealed possible PTE repair, this was determined not to play a role in the observed nonrandom manifestation in vivo [Le Pla et al. (2004) Chem. Res. Toxicol. 17, 1491-1500]. In the present study, to determine whether the nonrandom manifestation of PTEs in vivo was specifically due to their nonrandom formation, we have compared the in vitro formation of diethylsulfate (DES)-induced PTEs in h2E1/OR human B-lymphoblastoid cells, their isolated nuclei, and their isolated DNA, using the 5' nearest neighbor analysis postlabeling procedure developed by Le Pla et al.. Furthermore, to determine the role of electrophile character in PTE manifestation, prepared oligonucleotides ([dT](20)[dG](20):[dC](20)[dA](20)) were treated with three alkylating agents of differing electrophilic character (DES, methylnitrosourea, and ethylnitrosourea), and PTE manifestation was assessed by postlabeling. The formation of PTEs was determined to be nonrandom in the whole cells, nuclei, and DNA, with PTEs being formed to a greater extent 3' to pyrimidine moieties than 3' to purine moieties. The studies with the oligonucleotides confirm these observations and demonstrate that the nonrandom formation of PTEs is primarily determined by DNA sequence, and not by DNA packaging/chromatin factors, and that the extent of the nonrandom formation of PTEs is also governed by electrophile reactivity, with the more reactive electrophiles yielding a more random formation of PTEs. From our observations, we propose a model for the nonrandom formation of PTEs, which is governed by (i) the phosphate oxygens having to compete with adjacent nucleophilic sites for the alkylating electrophile and (ii) the electrophile's inherent

  19. DNA adducts induced by in vitro activation of diesel and biodiesel exhaust extracts

    Science.gov (United States)

    The abstract reports the results of studies assessing the relative DNA damage potential of extracts of exhaust particles resulting from the combustion of petroleum diesel, biodiesel, and petroleum diesel-biodiesel blends. Results indicate that the commercially available B20 petr...

  20. Molecular modeling and spectroscopic studies of semustine binding with DNA and its comparison with lomustine-DNA adduct formation.

    Science.gov (United States)

    Agarwal, Shweta; Chadha, Deepti; Mehrotra, Ranjana

    2015-01-01

    Chloroethyl nitrosoureas constitute an important family of cancer chemotherapeutic agents, used in the treatment of various types of cancer. They exert antitumor activity by inducing DNA interstrand cross-links. Semustine, a chloroethyl nitrosourea, is a 4-methyl derivative of lomustine. There exist some interesting reports dealing with DNA-binding properties of chloroethyl nitrosoureas; however, underlying mechanism of cytotoxicity caused by semustine has not been precisely and completely delineated. The present work focuses on understanding semustine-DNA interaction to comprehend its anti-proliferative action at molecular level using various spectroscopic techniques. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy is used to determine the binding site of semustine on DNA. Conformational transition in DNA after semustine complexation is investigated using circular dichroism (CD) spectroscopy. Stability of semustine-DNA complexes is determined using absorption spectroscopy. Results of the present study demonstrate that semustine performs major-groove-directed DNA alkylation at guanine residues in an incubation-time-drug-concentration-dependent manner. CD spectral outcomes suggest partial transition of DNA from native B-conformation to C-form. Calculated binding constants (Ka) for semustine and lomustine interactions with DNA are 1.53 × 10(3) M(-1) and 8.12 × 10(3) M(-1), respectively. Moreover, molecular modeling simulation is performed to predict preferential binding orientation of semustine with DNA that corroborates well with spectral outcomes. Results based on comparative study of DNA-binding properties of semustine and lomustine, presented here, may establish a correlation between molecular structure and cytotoxicity of chloroethyl nitrosoureas that may be instrumental in the designing and synthesis of new nitrosourea therapeutics possessing better efficacy and fewer side effects.

  1. Role of hepatic cytochrome P450 enzymes in the detoxication of aristolochic acid I; effects on DNA adduct, mutation, and tumor formation.

    Science.gov (United States)

    Luan, Yang; Xing, Guozhen; Ren, Jin; Gu, Jun

    2015-01-01

    Hepatic cytochrome P450s (CYPs) play an important role in the metabolism of plant carcinogen, aristolochic acid I (AAI). In the present study, we employed hepatic NADPH-cytochrome P450 reductase null (HRN) gpt delta transgenic mice to investigate the role of hepatic CYPs in the metabolism of AAI. DNA adduct formation, gene mutation, and tumor induction in the liver and kidneys were analyzed. Pharmacokinetic analyses were performed and tissue levels of AAI were determined. Pretreatment with β-naphthoflavone in wild type gpt delta transgenic mice (BNF-WT mice) could increase the rate of clearance of AAI in blood and tissues, and decrease the formation of AAI-DNA adducts in kidney. In contrast, there was reduced clearance of AAI in HRN gpt delta mice, which showed increased concentration of AAI in tissues and increased levels of DNA adducts. The mutant frequencies of gpt gene, induced by AAI, in the kidneys of HRN gpt delta mice were significantly higher than that in WT mice. In the tumor induction assay, after treatment for 2 months with daily doses of 5 mg/kg AAI, mice were kept under observation for 7 months. During this period, papillomatous changes occurred in the forestomach of both WT-AAI mice and HRN gpt delta-AAI mice. Squamous cell carcinomas were found in the forestomach of 2 HRN gpt delta-AAI mice, which had also metastasized to other tissues. In addition, adenomas were found in 2 of 8 HRN gpt delta-AAI mice, in the absence of squamous cell carcinomas. These results indicated that the main role of hepatic CYPs is to aid in the excretion of AAI, and to protect the target organs against AAI induced DNA adduct formation, mutagenesis, and tumorigenesis.

  2. Sustained expression of CYPs and DNA adduct accumulation with continuous exposure to PCB126 and PCB153 through a new delivery method: Polymeric implants

    Directory of Open Access Journals (Sweden)

    Farrukh Aqil

    2014-01-01

    Full Text Available A new delivery method via polymeric implants was used for continuous exposure to PCBs. Female Sprague-Dawley rats received subcutaneous polymeric implants containing PCB126 (0.15% load, PCB153 (5% load, or both, for up to 45 d and release kinetics and tissue distribution were measured. PCB153 tissue levels on day 15 were readily detected in lung, liver, mammary and serum, with highest levels in the mammary tissue. PCB126 was detected only in liver and mammary tissues. However, a completely different pharmacokinetics was observed on co-exposure of PCB153 and PCB126, with a 1.8-fold higher levels of PCB153 in the liver whereas a 1.7-fold lower levels in the mammary tissue. PCB126 and PCB153 caused an increase in expression of key PCB-inducible enzymes, CYP 1A1/2 and 2B1/2, respectively. Serum and liver activities of the antioxidant enzymes, PON1 and PON3, and AhR transcription were also significantly increased by PCB126. 32P-postlabeling for polar and lipophilic DNA-adducts showed significant quantitative differences: PCB126 increased 8-oxodG, an oxidative DNA lesion, in liver and lung tissues. Adduct levels in the liver remained upregulated up to 45 d, while some lung DNA adducts declined. This is the first demonstration that continuous low-dose exposure to PCBs via implants can produce sustained tissue levels leading to the accumulation of DNA-adducts in target tissue and induction of indicator enzymes. Collectively, these data demonstrate that this exposure model is a promising tool for long-term exposure studies.

  3. Fat content and nitrite-curing influence the formation of oxidation products and NOC-specific DNA adducts during in vitro digestion of meat

    OpenAIRE

    Thomas van Hecke; Els Vossen; Julie Vanden Bussche; Katleen Raes; Lynn Vanhaecke; Stefaan De Smet

    2014-01-01

    The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes), protein oxidation products (protein carbonyl compounds) and NOC-specific DNA adducts (O-6-carboxy-methylguanine) during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption a...

  4. Metabolic activation and DNA adducts of dinitropyrenes. Research report, 1 January 1984-31 December 1985

    Energy Technology Data Exchange (ETDEWEB)

    Beland, F.A.

    1986-01-01

    The study explored the sequence of reactions through which nitrated pyrenes, important mutagenic and potentially carcinogenic components of diesel exhaust, are converted metabolically within bacterial and mammalian cells into reactive forms that damage DNA. Results indicate that (1) factors in addition to nitroreduction were involved in the metabolic activation of dinitropyrene, (2) differences exist among the nitropyrene compounds tested in the mechanism of nitroreduction, (3) reduction to 1-nitrosopyrene is the limiting step in the metabolic activation of 1-nitropyrene, while subsequent esterification of the reduced intermediates is critical for the activation of the dinitropyrenes, (4) the extent of DNA binding of the different compounds was correlated with the extent of their nitroreduction, and (5) anaerobic intestinal microflora play an important role in metabolizing orally administered nitropyrenes.

  5. Synthesis, characterization and DNA cleavage activity of nickel(II adducts with aromatic heterocyclic bases

    Directory of Open Access Journals (Sweden)

    G. H. PHILIP

    2010-01-01

    Full Text Available Mixed ligand complexes of nickel(II with 2,4-dihydroxyaceto-phenone oxime (DAPO and 2,4-dihydroxybenzophenone oxime (DBPO as primary ligands, and pyridine (Py and imidazole (Im as secondary ligands were synthesized and characterized by molar conductivity, magnetic moments measurements, as well as by electronic, IR, and 1H-NMR spectroscopy. Electrochemical studies were performed by cyclic voltammetry. The active signals are assignable to the NiIII/II and NiII/I redox couples. The binding interactions between the metal complexes and calf thymus DNA were investigated by absorption and thermal denaturation. The cleavage activity of the complexes was determined using double-stranded pBR322 circular plasmid DNA by gel electrophoresis. All complexes showed increased nuclease activity in the presence of the oxidant H2O2. The nuclease activities of mixed ligand complexes were compared with those of the parent copper(II complexes.

  6. Astragalin from Cassia alata Induces DNA Adducts in Vitro and Repairable DNA Damage in the Yeast Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Martin Brendel

    2012-03-01

    Full Text Available Reverse phase-solid phase extraction from Cassia alata leaves (CaRP was used to obtain a refined extract. Higher than wild-type sensitivity to CaRP was exhibited by 16 haploid Saccharomyces cerevisiae mutants with defects in DNA repair and membrane transport. CaRP had a strong DPPH free radical scavenging activity with an IC50 value of 2.27 µg mL−1 and showed no pro-oxidant activity in yeast. CaRP compounds were separated by HPLC and the three major components were shown to bind to DNA in vitro. The major HPLC peak was identified as kampferol-3-O-β-D-glucoside (astragalin, which showed high affinity to DNA as seen by HPLC-UV measurement after using centrifugal ultrafiltration of astragalin-DNA mixtures. Astragalin-DNA interaction was further studied by spectroscopic methods and its interaction with DNA was evaluated using solid-state FTIR. These and computational (in silico docking studies revealed that astragalin-DNA binding occurs through interaction with G-C base pairs, possibly by intercalation stabilized by H-bond formation.

  7. Astragalin from Cassia alata induces DNA adducts in vitro and repairable DNA damage in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Saito, Samuel; Silva, Givaldo; Santos, Regineide Xavier; Gosmann, Grace; Pungartnik, Cristina; Brendel, Martin

    2012-01-01

    Reverse phase-solid phase extraction from Cassia alata leaves (CaRP) was used to obtain a refined extract. Higher than wild-type sensitivity to CaRP was exhibited by 16 haploid Saccharomyces cerevisiae mutants with defects in DNA repair and membrane transport. CaRP had a strong DPPH free radical scavenging activity with an IC(50) value of 2.27 μg mL(-1) and showed no pro-oxidant activity in yeast. CaRP compounds were separated by HPLC and the three major components were shown to bind to DNA in vitro. The major HPLC peak was identified as kampferol-3-O-β-d-glucoside (astragalin), which showed high affinity to DNA as seen by HPLC-UV measurement after using centrifugal ultrafiltration of astragalin-DNA mixtures. Astragalin-DNA interaction was further studied by spectroscopic methods and its interaction with DNA was evaluated using solid-state FTIR. These and computational (in silico) docking studies revealed that astragalin-DNA binding occurs through interaction with G-C base pairs, possibly by intercalation stabilized by H-bond formation.

  8. Modulation of Estrogen-Depurinating DNA Adducts by Sulforaphane for Breast Cancer

    Science.gov (United States)

    2014-12-01

    quinone (E1-3,4-Q) and 17β-estradiol 3,4- quinone (E2-3,4-Q) were synthesized using activated manganese dioxide (MnO2) as oxidizing agent. The...20 μ l volume including each target primer, complementary DNA and iQ ™ SYBR® Green Supermix (Bio-Rad, Hercules, CA) and run in a Bio-Rad Thermal... iQ ™ SYBR® Green Supermix (Bio-Rad, Hercules, CA) and run in a Bio-Rad Thermal Cycler (Bio-Rad, Hamburg, Germany). Fold- change values were determined

  9. Metabolism of aflatoxin B1 and identification of the major aflatoxin B1-DNA adducts formed in cultured human bronchus and colon

    DEFF Research Database (Denmark)

    1979-01-01

    Aflatoxin B1 and benzo(a)pyrene were activated by both cultured human bronchus and human colon as measured by binding to cellular DNA and protein. The binding of aflatoxin B1 to DNA was dose dependent, and the level of binding was higher in cultured human bronchus than it was in the colon. When...... compared to aflatoxin B1, the binding level of benzo(a)pyrene to both bronchial and colonic DNA was generally higher. The major adducts formed in both tissues by the interaction of aflatoxin B1 and DNA were chromatographically identical to 2,3-dihydro-2-(N7-guanyl)-3-hydroxyaflatoxin B1 (Structure 1...... in these two peaks, and the ratio of radioactivity between the peaks was nearly 1. In colonic DNA, the ratio between Structures 1 and 11 was approximately 2. These observations add aflatoxin B1 to the list of chemical procarcinogens metabolized by cultured human tissues and in which the carcinogen-DNA adducts...

  10. The repair of melphalan-induced DNA adducts in the transcribed strand of active genes is subject to a strong polarity effect.

    OpenAIRE

    Episkopou, Hara; Kyrtopoulos, Soterios A.; Sfikakis, Petros P.; Meletios A Dimopoulos; Souliotis, Vassilis L

    2011-01-01

    To investigate the mechanisms of the therapeutic action and drug resistance to the nitrogen mustard melphalan, melphalan-induced DNA damage repair and chromatin structure were examined along the p53, N-ras and d-globin gene loci in cells carrying different repair activities. In nucleotide excision repair-deficient XP-A cells, similar levels of adducts were found in all fragments examined, indicating uniform distribution of DNA damage. In both, repair-proficient CS-B and XP-C cells, faster rep...

  11. Accumulation and persistence of nicotine derived DNA and hemoglobin adducts in mice after multiple administration of {sup 14}C-nicotine at low dose level

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hongfang; Li, Hongli; Zhu, Jiadan; Wang, Haifang; Liu, Yuanfang [Peking Univ., Beijing (China). Dept. of Chemical Biology, College of Chemistry and Molecular Engineering; Liu, Kexin; Peng, Shixiang [Peking Univ., Beijing (China). Inst. of Heavy Ion Physics, School of Physics

    2004-07-01

    The hypothetic role of nicotine in causing smoking related diseases has not been well established. Based on our early finding of the genotoxicity of nicotine, a sub-chronic study on the accumulation and persistence of nicotine derived DNA and hemoglobin (Hb) adducts in mice following multiple low dose exposures was carried out by accelerator mass spectrometry (AMS). AMS is a sophisticated ultrasensitive nuclear method, which facilitates the detection of adduction of DNA and other bio-macromolecules with xenobiotics at human relevant environmental dose levels. Briefly, in this study [N-{sup 14}CH{sub 3}]-nicotine (s.a. 16.2 {mu}Ci/{mu}mol) was administered to mice by gavage once daily at 3.0 {mu}g/kg b.w., which is equivalent to an estimated nicotine dose inhaled by a 70 kg person smoking 5 cigarettes, for 14 consecutive days. Lung DNA, liver DNA and Hb were isolated from tissues and blood samples which were collected at 1, 3, 5, 7, 10, 14, 15, 17, 21 and 25 days time point, respectively. (orig.)

  12. Mechanism of Error-Free Bypass of the Environmental Carcinogen N-(2'-Deoxyguanosin-8-yl)-3-aminobenzanthrone Adduct by Human DNA Polymerase η.

    Science.gov (United States)

    Patra, Amritraj; Politica, Dustin A; Chatterjee, Arindom; Tokarsky, E John; Suo, Zucai; Basu, Ashis K; Stone, Michael P; Egli, Martin

    2016-11-03

    The environmental pollutant 3-nitrobenzanthrone produces bulky aminobenzanthrone (ABA) DNA adducts with both guanine and adenine nucleobases. A major product occurs at the C8 position of guanine (C8-dG-ABA). These adducts present a strong block to replicative polymerases but, remarkably, can be bypassed in a largely error-free manner by the human Y-family polymerase η (hPol η). Here, we report the crystal structure of a ternary Pol⋅DNA⋅dCTP complex between a C8-dG-ABA-containing template:primer duplex and hPol η. The complex was captured at the insertion stage and provides crucial insight into the mechanism of error-free bypass of this bulky lesion. Specifically, bypass involves accommodation of the ABA moiety inside a hydrophobic cleft to the side of the enzyme active site and formation of an intra-nucleotide hydrogen bond between the phosphate and ABA amino moiety, allowing the adducted guanine to form a standard Watson-Crick pair with the incoming dCTP. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. NAD(P)H:quinone oxidoreductase 1 Arg139Trp and Pro187Ser polymorphisms imbalance estrogen metabolism towards DNA adduct formation in human mammary epithelial cells.

    Science.gov (United States)

    Singh, Seema; Zahid, Muhammad; Saeed, Muhammad; Gaikwad, Nilesh W; Meza, Jane L; Cavalieri, Ercole L; Rogan, Eleanor G; Chakravarti, Dhrubajyoti

    2009-10-01

    Estrogens (estrone, E(1); estradiol, E(2)) are oxidized in the breast first to catechols and then to form two ortho-quinones (E(1/2)-3,4-Q) that react with DNA to form depurinating adducts, which lead to mutations associated with breast cancer. NAD(P)H:quinone oxidoreductase 1 (NQO1) reduces these quinones back to catechols, and thus may protect against this mechanism. We examined whether the inheritance of two polymorphic variants of NQO1 (Pro187Ser or Arg139Trp) would result in poor reduction of E(1/2)-3,4-Q in normal human mammary epithelial cells (MCF-10F) and increased depurinating adduct formation. An isogenic set of stably transfected normal human breast epithelial cells (MCF-10F) that express a truncated (135Stop), the wild-type, the 139Trp variant or the 187Ser variant of human NQO1 cDNA was constructed. MCF-10F cells showed a low endogenous NQO1 activity. NQO1 expression was examined by RT-PCR and Western blotting, and catalytic activity of reducing E(2)-3,4-Q to 4-hydroxyE(1/2) and associated changes in the levels of quinone conjugates (4-methoxyE(1/2), 4-OHE(1/2)-2-glutathione, 4-OHE(1/2)-2-Cys and 4-OHE(1/2)-2-N-acetylcysteine) and depurinating DNA adducts (4-OHE(1/2)-1-N3Ade and 4-OHE(1/2)-1-N7Gua) were examined by HPLC with electrochemical detection, as well as by ultra-performance liquid chromatography with tandem mass spectrometry. The polymorphic variants transcribed comparably to the wild-type NQO1, but produced approximately 2-fold lower levels of the protein, suggesting that the variant proteins may become degraded. E(1/2)-3,4-Q toxicity to MCF-10F cells (IC50=24.74 microM) was increased (IC50=3.7 microM) by Ro41-0960 (3 microM), a catechol-O-methyltransferase inhibitor. Cells expressing polymorphic NQO1 treated with E(2)-3,4-Q with or without added Ro41-0960, showed lower ability to reduce the quinone ( approximately 50% lower levels of the free catechols and approximately 3-fold lower levels of methylated catechols) compared to the wild

  14. Recovery from Cogwheel Rigidity and Akinesia and Improvement in Vibration Sense and Olfactory Perception following Removal of an Epoxy-Oleic Acid DNA Adduct

    Directory of Open Access Journals (Sweden)

    Jean A. Monro

    2017-01-01

    Full Text Available The epoxy fatty acid cis-12,13-epoxy-oleic acid, which acts as a DNA adduct, may be generated during long-term storage of many seed oils, including those used in cooking, with frying oils and fried foods being a major source in the modern human diet. Removal of this epoxy fatty acid from the locus of the N-formyl peptide receptors was associated with recovery from cogwheel rigidity and akinesia as well as with improvement in vibration sense and olfactory perception.

  15. Typical signature of DNA damage in white blood cells: a pilot study on etheno adducts in Danish mother-newborn child pairs

    DEFF Research Database (Denmark)

    Arab, K; Pedersen, Marie; Nair, J

    2009-01-01

    The impact of DNA damage commonly thought to be involved in chronic degenerative disease causation is particularly detrimental during fetal development. Within a multicenter study, we analyzed 77 white blood cell (WBC) samples from mother-newborn child pairs to see if imprinting of DNA damage...... reliably detectable and about two times lower in child cord blood, the difference being significant at P ... arising from endogenous reactive aldehydes in WBC of both mother and newborn can be reliably assessed by epsilondA and epsilondC as biomarkers. The high correlation of etheno adduct levels in mother and child WBC suggests that a typical signature of DNA damage is induced similarly in fetus and mother...

  16. Verification, Dosimetry and Biomonitoring of Mustard Gas Exposure via Immunochemical Detection of Mustard Gas Adducts to DNA and Proteins

    Science.gov (United States)

    1991-12-01

    colmtitor. .198 Figure 81; Competitive ELISA with rabbit serum 11/10 and single-stranded calf- thyms DM as compet I tor. 199 Figure 8: Competitive ELISA...described betore. It could be concluded. therefore. that the same three major .adducts were formed it, whole blood as in calf-. thym ~s DN treated with

  17. Detection of 1,N(2)-propano-2'-deoxyguanosine adducts in genomic DNA by ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry in combination with stable isotope dilution.

    Science.gov (United States)

    Zhang, Ning; Song, Yuanyuan; Wu, Danni; Xu, Tian; Lu, Meiling; Zhang, Weibing; Wang, Hailin

    2016-06-10

    Crotonaldehyde (Cro) is one of widespread and genotoxic α,β-unsaturated aldehydes and can react with the exocyclic amino group of 2'-deoxyguanosine (dG) in genomic DNA to form 1,N(2)-propano-2'-deoxyguanosine (ProdG) adducts. In this study, two diastereomers of high purity were prepared, including non-isotope and stable isotope labeled ProdG adducts, and exploited stable isotope dilution-based calibration method. By taking advantage of synthesized ProdG standards, we developed a sensitive ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for accurate quantification of two diastereomers of ProdG adducts. In addition to optimization of the UHPLC separation, ammonium bicarbonate (NH4HCO3) was used as additive in the mobile phase for enhancing the ionization efficiency to ProdG adducts and facilitating MS detection. The limits of detection (LODs, S/N=3) and the limits of quantification (LOQs, S/N=10) are estimated about 50 amol and 150 amol, respectively. By the use of the developed method, both diastereomers of ProdG adducts can be detected in untreated human MRC5 cells with a frequency of 2.4-3.5 adducts per 10(8) nucleotides. Crotonaldehyde treatment dramatically increases the levels of ProdG adducts in human MRC5 in a concentration-dependent manner. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A biomarker model of sublethal genotoxicity (DNA single-strand breaks and adducts) using the sentinel organism Aporrectodea longa in spiked soil.

    Science.gov (United States)

    Martin, Francis L; Piearce, Trevor G; Hewer, Alan; Phillips, David H; Semple, Kirk T

    2005-11-01

    There is a need to develop risk biomarkers during the remediation of contaminated land. We employed the earthworm, Aporrectodea longa (Ude), to determine whether genotoxicity measures could be applied to this organism's intestinal tissues. Earthworms were added, for 24h or 7 days, to soil samples spiked with benzo[a]pyrene (B[a]P) and/or lindane. After exposure, intestinal tissues (crop/gizzard or intestine) were removed prior to the measurement in disaggregated cells of DNA single-strand breaks (SSBs) by the alkaline comet assay. Damage was quantified by comet tail length (CTL, microm). B[a]P 24-h exposure induced dose-related increases (P<0.0001) in SSBs. Earthworm intestine was significantly (P<0.0001) more susceptible than crop/gizzard to B[a]P and/or lindane. However, both tissues appeared to acquire resistance following 7-day exposure. B[a]P-DNA adducts, measured by (32)P-postlabelling, showed a two-adduct-spot pattern. This preliminary investigation suggests that earthworm tissues may be incorporated into genotoxicity assays to facilitate hazard identification within terrestrial ecosystems.

  19. A biomarker model of sublethal genotoxicity (DNA single-strand breaks and adducts) using the sentinel organism Aporrectodea longa in spiked soil

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Francis L. [Department of Biological Sciences, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster LA1 4YQ (United Kingdom)]. E-mail: f.martin@lancaster.ac.uk; Piearce, Trevor G. [Department of Biological Sciences, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Hewer, Alan [Institute of Cancer Research, Brookes Lawley Building, Cotswold Road, Sutton, Surrey SM2 5NG (United Kingdom); Phillips, David H. [Institute of Cancer Research, Brookes Lawley Building, Cotswold Road, Sutton, Surrey SM2 5NG (United Kingdom); Semple, Kirk T. [Department of Environmental Science, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2005-11-15

    There is a need to develop risk biomarkers during the remediation of contaminated land. We employed the earthworm, Aporrectodea longa (Ude), to determine whether genotoxicity measures could be applied to this organism's intestinal tissues. Earthworms were added, for 24 h or 7 days, to soil samples spiked with benzo[a]pyrene (B[a]P) and/or lindane. After exposure, intestinal tissues (crop/gizzard or intestine) were removed prior to the measurement in disaggregated cells of DNA single-strand breaks (SSBs) by the alkaline comet assay. Damage was quantified by comet tail length (CTL, {mu}m). B[a]P 24-h exposure induced dose-related increases (P<0.0001) in SSBs. Earthworm intestine was significantly (P<0.0001) more susceptible than crop/gizzard to B[a]P and/or lindane. However, both tissues appeared to acquire resistance following 7-day exposure. B[a]P-DNA adducts, measured by {sup 32}P-postlabelling, showed a two-adduct-spot pattern. This preliminary investigation suggests that earthworm tissues may be incorporated into genotoxicity assays to facilitate hazard identification within terrestrial ecosystems. - Sublethal genotoxicity in the sentinel organism A. longa can be used to monitor the effects of contaminants in soil.

  20. Biomarkers of genotoxicity of air pollution (the AULIS project): bulky DNA adducts in subjects with moderate to low exposures to airborne polycyclic aromatic hydrocarbons and their relationship to environmental tobacco smoke and other parameters

    DEFF Research Database (Denmark)

    Georgiadis, P.; Topinka, J.; Stoikidou, M.

    2001-01-01

    The levels of bulky DNA adducts were measured by (32)P-post-labelling in lymphocytes of 194 non-smoking students living in the city of Athens and the region of Halkida, Greece, once in the winter and again in the following summer. Personal exposures to particulate-bound polycyclic aromatic...... hydrocarbons (PAH) were significantly higher in Athens subjects during both seasons. There was hardly any diagonal radioactive zone in the pattern of DNA adducts observed. Highest adduct levels were observed in a sub-group of subjects living in or near the Halkida Institute campus, which was located in rural...... tobacco smoke (ETS), namely (i) declared times of exposure to ETS during the 24 h prior to blood donation, (ii) plasma cotinine levels and (iii) chrysene/benzo[g,h,i]perylene ratios in the profile of personal PAH exposure. Furthermore, among the Halkida campus area subjects (but not the remaining subjects...

  1. Isolevuglandin adducts in disease.

    Science.gov (United States)

    Salomon, Robert G; Bi, Wenzhao

    2015-06-20

    A diverse family of lipid-derived levulinaldehydes, isolevuglandins (isoLGs), is produced by rearrangement of endoperoxide intermediates generated through both cyclooxygenase (COX) and free radical-induced cyclooxygenation of polyunsaturated fatty acids and their phospholipid esters. The formation and reactions of isoLGs with other biomolecules has been linked to alcoholic liver disease, Alzheimer's disease, age-related macular degeneration, atherosclerosis, cardiac arythmias, cancer, end-stage renal disease, glaucoma, inflammation of allergies and infection, mitochondrial dysfunction, multiple sclerosis, and thrombosis. This review chronicles progress in understanding the chemistry of isoLGs, detecting their production in vivo and understanding their biological consequences. IsoLGs have never been isolated from biological sources, because they form adducts with primary amino groups of other biomolecules within seconds. Chemical synthesis enabled investigation of isoLG chemistry and detection of isoLG adducts present in vivo. The first peptide mapping and sequencing of an isoLG-modified protein present in human retina identified the modification of a specific lysyl residue of the sterol C27-hydroxylase Cyp27A1. This residue is preferentially modified by iso[4]LGE2 in vitro, causing loss of function. Adduction of less than one equivalent of isoLG can induce COX-associated oligomerization of the amyloid peptide Aβ1-42. Adduction of isoLGE2 to phosphatidylethanolamines causes gain of function, converting them into proinflammatory isoLGE2-PE agonists that foster monocyte adhesion to endothelial cells. Among the remaining questions on the biochemistry of isoLGs are the dependence of biological activity on isoLG isomer structure, the structures and mechanism of isoLG-derived protein-protein and DNA-protein cross-link formation, and its biological consequences.

  2. Systems toxicology approach to understand the kinetics of benzo(a)pyrene uptake, biotransformation, and DNA adduct formation in a liver cell model.

    Science.gov (United States)

    Madureira, Danielle J; Weiss, Frederik T; Van Midwoud, Paul; Helbling, Damian E; Sturla, Shana J; Schirmer, Kristin

    2014-03-17

    Cell-based models are important for deriving mechanistic information about stress response pathways that have evolved to protect cells from toxic insult, such as exposure to environmental pollutants. One determinant of the stress response is the amount of chemical entering the cell and the cell's ability to detoxify and remove the chemical. If the stress response is overwhelmed, an adverse outcome will ensue. It was the goal of our study to quantify uptake and elimination rates of benzo(a)pyrene (BaP), a ubiquitous environmental pollutant, in a murine liver cell line. We evaluated the kinetic behavior in the context of BaP uptake, biotransformation, DNA adduct formation and repair along with the transcriptional and cell proliferation response. A low (50 nM) and a high (5 μM) BaP concentration were chosen in order to differentiate the role of exposure concentration in the time-resolved interaction of BaP with cells. While rates of uptake and the initial transcriptional response were similar for both BaP concentrations, cells exposed to 50 nM BaP completely recovered from exposure within 24 h, whereas cells exposed to 5 μM BaP did not. Biotransformation proceeded faster on 50 nM BaP, and the few DNA adducts formed were completely repaired after transient cell cycle arrest. In contrast, DNA adducts greatly accumulated in cells exposed to 5 μM BaP, despite significant biotransformation; complete cell cycle arrest and toxicity evolved. On the basis of the kinetic rate constants and cellular response, we conclude that at least short-term, pulsed exposures to 50 nM BaP, which we consider environmentally relevant, can be handled by cells without adverse outcome. Further studies are needed to determine the ability of cells to recover from repeated exposure. Our study emphasizes the importance of quantifying chemical uptake and fate in cell models to differentiate a stress response from an adverse outcome for better risk assessment.

  3. Serum Level of Antibodies (IgG, IgM Against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in Children Dermatologically Exposed to Coal Tar

    Directory of Open Access Journals (Sweden)

    Pavel Borský

    2017-06-01

    Full Text Available Crude coal tar (CCT contains polycyclic aromatic hydrocarbons (PAHs. Benzo[a]pyrene (BaP is metabolized into a highly reactive metabolite benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE that is able to bind to DNA and creates BPDE-DNA adducts. Adducted DNA becomes immunogenic and induces immune response by production of antibodies against BPDE-DNA adducts (Ab-BPDE-DNA. Circulating Ab-BPDE-DNA was proposed as potential biomarker of genotoxic exposure to BaP (PAHs. Goeckerman therapy (GT of psoriasis uses dermal application of CCT ointment (PAHs. In presented study (children with psoriasis treated by GT; n = 19 the therapy significantly increased the level of Ab-BPDE-DNA (EI = 0.29/0.19–0.34 vs. 0.31/0.25–0.40; median/lower–upper quartile; p < 0.01. The results support the idea of Ab-BPDE-DNA level as a possible tentative indicator of exposure, effects and susceptibility of the organism to the exposure of BaP (PAHs.

  4. The relevance of monitoring of antibodies against the polycyclic aromatic hydrocarbon (PAH) and PAH-DNA adducts in serum in relation to lung cancer and chronic obstructive pulmonary disease (COPD)

    Czech Academy of Sciences Publication Activity Database

    Pauk, N.; Klimešová, Š.; Kára, J.; Topinka, Jan; Lábaj, J.

    2013-01-01

    Roč. 60, č. 2 (2013), s. 182-187 ISSN 0028-2685 R&D Projects: GA MŠk 2B06150 Institutional support: RVO:68378041 Keywords : polycyclic aromatic hydrocarbons * anti-PAH antibodies * DNA adducts Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 1.642, year: 2013

  5. BENZO[A]PYRENE-7,8-QUINONE FORMS COVALENT-DNA ADDUCTS IN VITRO BUT NONE WERE DETECTED IN THE LUNGS OR LIVERS OF STRAIN A/J MICE IN VIVO

    Science.gov (United States)

    Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of B[a]P-7,8-dio1-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: 1.] The induction of apurinic sites from radical cati...

  6. Basil extract inhibits the sulfotransferase mediated formation of DNA adducts of the procarcinogen 1'-hydroxyestragole by rat and human liver S9 homogenates and in HepG2 human hepatoma cells

    NARCIS (Netherlands)

    Jeurissen, S.M.F.; Punt, A.; Delatour, T.; Rietjens, I.M.C.M.

    2008-01-01

    The effects of a basil extract on the sulfation and concomitant DNA adduct formation of the proximate carcinogen 1¿-hydroxyestragole were studied using rat and human liver S9 homogenates and the human hepatoma cell line HepG2. Basil was chosen since it contains the procarcinogen estragole that can

  7. 3-aminobenzanthrone, a human metabolite of the environmental pollutant 3-nitrobenzanthrone, forms DNA adducts after metabolic activation by human and rat liver microsomes: evidence for activation by cytochrome P450 1A1 and P450 1A2.

    Science.gov (United States)

    Arlt, Volker M; Hewer, Alan; Sorg, Bernd L; Schmeiser, Heinz H; Phillips, David H; Stiborova, Marie

    2004-08-01

    3-Nitrobenzanthrone (3-NBA) is a suspected human carcinogen found in diesel exhaust and ambient air pollution. The main metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), was recently detected in the urine of salt mining workers occupationally exposed to diesel emissions. Determining the capability of humans to metabolize 3-ABA and understanding which human enzymes are involved in its activation are important in the assessment of individual susceptibility. We compared the ability of eight human hepatic microsomal samples to catalyze DNA adduct formation by 3-ABA. Using the (32)P-postlabeling method, we found that all hepatic microsomes were competent to activate 3-ABA. DNA adduct patterns with multiple adducts, qualitatively similar to those formed in vivo in rats treated with 3-ABA, were observed. These patterns were also similar to those formed by the nitroaromatic counterpart 3-NBA and which derive from reductive metabolites of 3-NBA bound to purine bases in DNA. The role of specific cytochrome P450s (P450s) in the human hepatic microsomal samples in 3-ABA activation was investigated by correlating the P450-linked catalytic activities in each microsomal sample with the level of DNA adducts formed by the same microsomes. On the basis of this analysis, most of the hepatic microsomal activation of 3-ABA was attributable to P450 1A1 and 1A2 enzyme activity. Inhibition of DNA adduct formation in human liver microsomes by alpha-naphthoflavone and furafylline, inhibitors of P450 1A1 and 1A2, and P450 1A2 alone, respectively, supported this finding. Using recombinant human P450 1A1 and 1A2 expressed in Chinese hamster V79 cells and microsomes of baculovirus-transfected insect cells (Supersomes), we confirmed the participation of these enzymes in the formation of 3-ABA-derived DNA adducts. Moreover, essentially the same DNA adduct pattern found in microsomes was detected in metabolically competent human lymphoblastoid MCL-5 cells expressing P450 1A1 and 1A2. Using rat

  8. In vitro complementation of Tdp1 deficiency indicates a stabilized enzyme-DNA adduct from tyrosyl but not glycolate lesions as a consequence of the SCAN1 mutation.

    Science.gov (United States)

    Hawkins, Amy J; Subler, Mark A; Akopiants, Konstantin; Wiley, Jenny L; Taylor, Shirley M; Rice, Ann C; Windle, Jolene J; Valerie, Kristoffer; Povirk, Lawrence F

    2009-05-01

    A homozygous H493R mutation in the active site of tyrosyl-DNA phosphodiesterase (TDP1) has been implicated in hereditary spinocerebellar ataxia with axonal neuropathy (SCAN1), an autosomal recessive neurodegenerative disease. However, it is uncertain how the H493R mutation elicits the specific pathologies of SCAN1. To address this question, and to further elucidate the role of TDP1 in repair of DNA end modifications and general physiology, we generated a Tdp1 knockout mouse and carried out detailed behavioral analyses as well as characterization of repair deficiencies in extracts of embryo fibroblasts from these animals. While Tdp1(-/-) mice appear phenotypically normal, extracts from Tdp1(-/-) fibroblasts exhibited deficiencies in processing 3'-phosphotyrosyl single-strand breaks and 3'-phosphoglycolate double-strand breaks (DSBs), but not 3'-phosphoglycolate single-strand breaks. Supplementing Tdp1(-/-) extracts with H493R TDP1 partially restored processing of 3'-phosphotyrosyl single-strand breaks, but with evidence of persistent covalent adducts between TDP1 and DNA, consistent with a proposed intermediate-stabilization effect of the SCAN1 mutation. However, H493R TDP1 supplementation had no effect on phosphoglycolate (PG) termini on 3' overhangs of double-strand breaks; these remained completely unprocessed. Altogether, these results suggest that for 3'-phosphoglycolate overhang lesions, the SCAN1 mutation confers loss of function, while for 3'-phosphotyrosyl lesions, the mutation uniquely stabilizes a reaction intermediate.

  9. Tetrahydroxylated-benzo[a]pyrene isomer analysis after hydrolysis of DNA-adducts isolated from rat and human white blood cells.

    Science.gov (United States)

    Grova, Nathalie; Salquèbre, Guillaume; Hardy, Emilie M; Schroeder, Henri; Appenzeller, Brice M R

    2014-10-17

    Since exposure to benzo[a]pyrene is suspected to be associated with several health issues, significant efforts have been made to develop efficient strategies for the assessment of human exposure to this ubiquitous compound. In this context, a method was developed for the analysis of four tetrahydroxylated-benzo[a]pyrene isomers resulting from the hydrolysis of their respective diol-epoxide precursors which are involved in DNA-adduct formation. The analytical sensitivity necessary to reach environmental levels of concentration was obtained by using gas chromatography-tandem mass spectrometry. The recovery determined at the four concentration levels were estimated in average at 83% for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±), 29% for benzo[a]pyrene-r-7,t-8,t-9,t-10-tetrahydrotetrol(±), and 82% for benzo[a]pyrene-r-7,t-8,C-9,c-10-tetrahydrotetrol(±). The coefficient of determination of the calibration curve was above 0.997 for all the analytes investigated and the limit of quantification ranged from 0.5 to 2 adduct/10(8) nucleotides. The precision was between 5.3% and 22.3%. The suitability of the method was firstly evaluated by the analysis of DNA isolated from white blood cells of rats submitted after controlled exposure to benzo[a]pyrene. The four targeted tetra-OH-benzo[a]pyrenes as well as two unknown isomers were detected in all the treated animals. Benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol(±) appeared as the most abundant isomer in both treated and control animals followed by benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±). The method was afterwards applied to the analysis of DNA isolated from white blood cells of human volunteers. The results confirmed that this method was sufficiently sensitive to monitor environmental levels of exposure since all the specimens analyzed were above the limit of quantification for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol(±) and two of them were positive for benzo[a]pyrene-r-7,t-8,c-9,c-10

  10. Metabolism of benzo(a)pyrene, N-nitrosomethylamine, and N-nitrosopyrrolidine and identification of the major carcinogen-DNA adducts formed in cultured human esophagus

    DEFF Research Database (Denmark)

    Harris, Curtis C.; Autrup, Herman; Stoner, Gary D.

    1979-01-01

    (a)pyrene (BP), N-nitrosodimethylamine (DMN), and A/-nitrosopyrrolidine in cultured nontumorous esophagus from two patients with and six patients without esophageal carcinoma. Esophageal explants were cultured in a chemically defined medium for 7 days prior to adding [3H]BP (1.5 JUM),[14C]DMN (100 /IM), or [14C......]Nnitrosopyrrolidine (100 /¿M)for 24 hr. Radioactivity was found bound to both mucosal protein (BP, DMN, and A/-nitrosopyrrolidine) and DMA (BP and DMN). The major carcinogen-DNA adducts were: (a) with BP, N2-[10/?-(7/?,8a,9a-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyrenyl)]deoxyguanosine; and (fa) with DMN, 7-methylguanine......%), and glutathione conjugates (24 to 66%)] and of organic-extractable metabolites were similar in all patients. Whether or not quantitative differences in carcinogen metabolism and in carcinogen bound to esophageal DNA will play a role in human susceptibility to environmental chemical carcinogens is not as yet known....

  11. Kin3 protein, a NIMA-related kinase of Saccharomyces cerevisiae, is involved in DNA adduct damage response.

    Science.gov (United States)

    Moura, Dinara J; Castilhos, Bruna; Immich, Bruna F; Cañedo, Andrés D; Henriques, João A P; Lenz, Guido; Saffi, Jenifer

    2010-06-01

    Kin3 is a nonessential serine/threonine protein kinase of the budding yeast Saccharomyces cerevisiae with unknown cellular role. It is an ortholog of the Aspergillus nidulans protein kinase NIMA (Never-In Mitosis, gene A), which is involved in the regulation of G2/M phase progression, DNA damage response and mitosis. The aim of this study was to determine whether Kin3 is required for proper checkpoint activation and DNA repair. Here we show that KIN3 gene deficient cells present sensitivity and fail to arrest properly at G2/M-phase checkpoint in response to the DNA damage inducing agents MMS, cisplatin, doxorubicin and nitrogen mustard, suggesting that Kin3 can be involved in DNA strand breaks recognition or signaling. In addition, there is an increase in KIN3 gene expression in response to the mutagenic treatment, which was confirmed by the increase of Kin3 protein. We also showed that co-treatment with caffeine induces a slight increase in the susceptibility to genotoxic agents in kin3 cells and abolishes KIN3 gene expression in wild-type strain, suggesting that Kin3p can play a role in Tel1/Mec1-dependent pathway activation induced after genotoxic stress. These data provide the first evidence of the involvement of S. cerevisiae Kin3 in the DNA damage response.

  12. DNA adduct formation and oxidative stress in colon and liver of Big Blue rats after dietary exposure to diesel particles

    DEFF Research Database (Denmark)

    Dybdahl, Marianne; Risom, Lotte; Møller, Peter

    2003-01-01

    Exposure to diesel exhaust particles (DEP) via the gastrointestinal route may impose risk of cancer in the colon and liver. We investigated the effects of DEP given in the diet to Big Blue rats by quantifying a panel of markers of DNA damage and repair, mutation, oxidative damage to proteins and ...

  13. DNA adduct bypass polymerization by Sulfolobus solfataricus DNA polymerase Dpo4: analysis and crystal structures of multiple base pair substitution and frameshift products with the adduct 1,N2-ethenoguanine.

    Science.gov (United States)

    Zang, Hong; Goodenough, Angela K; Choi, Jeong-Yun; Irimia, Adriana; Loukachevitch, Lioudmila V; Kozekov, Ivan D; Angel, Karen C; Rizzo, Carmelo J; Egli, Martin; Guengerich, F Peter

    2005-08-19

    1,N(2)-Etheno(epsilon)guanine is a mutagenic DNA lesion derived from lipid oxidation products and also from some chemical carcinogens. Gel electrophoretic analysis of the products of primer extension by Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) indicated preferential incorporation of A opposite 3'-(1,N(2)-epsilon-G)TACT-5', among the four dNTPs tested individually. With the template 3'-(1,N(2)-epsilon-G)CACT-5', both G and A were incorporated. When primer extension was done in the presence of a mixture of all four dNTPs, high pressure liquid chromatography-mass spectrometry analysis of the products indicated that (opposite 3'-(1,N(2)-epsilon-G)CACT-5') the major product was 5'-GTGA-3' and the minor product was 5'-AGTGA-3'. With the template 3'-(1,N(2)-epsilon-G)TACT-5', the following four products were identified by high pressure liquid chromatography-mass spectrometry: 5'-AATGA-3', 5'-ATTGA-3', 5'-ATGA-3', and 5'-TGA-3'. An x-ray crystal structure of Dpo4 was solved (2.1 A) with a primer-template and A placed in the primer to be opposite the 1,N(2)-epsilon-G in the template 3'-(1,N(2)-epsilon-G)TACT 5'. The added A in the primer was paired across the template T with classic Watson-Crick geometry. Similar structures were observed in a ternary Dpo4-DNA-dATP complex and a ternary Dpo4-DNA-ddATP complex, with d(d)ATP opposite the template T. A similar structure was observed with a ddGTP adjacent to the primer and opposite the C next to 1,N(2)-epsilon-G in 3'-(1,N(2)-epsilon-G)CACT-5'. We concluded that Dpo4 uses several mechanisms, including A incorporation opposite 1,N(2)-epsilon-G and also a variation of dNTP-stabilized misalignment, to generate both base pair and frameshift mutations.

  14. Fat content and nitrite-curing influence the formation of oxidation products and NOC-specific DNA adducts during in vitro digestion of meat.

    Science.gov (United States)

    Van Hecke, Thomas; Vossen, Els; Vanden Bussche, Julie; Raes, Katleen; Vanhaecke, Lynn; De Smet, Stefaan

    2014-01-01

    The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes), protein oxidation products (protein carbonyl compounds) and NOC-specific DNA adducts (O6-carboxy-methylguanine) during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption and colorectal cancer risk. Digestion of uncured pork to which fat was added (total fat content 5 or 20%), resulted in significantly higher lipid and protein oxidation in the mimicked duodenal and colonic fluids, compared to digestion of pork without added fat (1% fat). A higher fat content also significantly favored the formation of O6-carboxy-methylguanine in the colon. Nitrite-curing of meat resulted in significantly lower lipid and protein oxidation before and after digestion, while an inconsistent effect on the formation of O6-carboxy-methylguanine was observed. The presented results demonstrate that haem-Fe is not solely responsible for oxidation and nitrosation reactions throughout an in vitro digestion approach but its effect is promoted by a higher fat content in meat.

  15. Nitrite curing of chicken, pork, and beef inhibits oxidation but does not affect N-nitroso compound (NOC)-specific DNA adduct formation during in vitro digestion.

    Science.gov (United States)

    Van Hecke, Thomas; Vanden Bussche, Julie; Vanhaecke, Lynn; Vossen, Els; Van Camp, John; De Smet, Stefaan

    2014-02-26

    Uncured and nitrite-cured chicken, pork, and beef were used as low, medium, and high sources of heme-Fe, respectively, and exposed to an in vitro digestion model simulating the mouth, stomach, duodenum, and colon. With increasing content of iron compounds, up to 25-fold higher concentrations of the toxic lipid oxidation products malondialdehyde, 4-hydroxy-2-nonenal, and other volatile aldehydes were formed during digestion, together with increased protein carbonyl compounds as measurement of protein oxidation. Nitrite curing of all meats lowered lipid and protein oxidation to the level of oxidation in uncured chicken. Strongly depending on the individual fecal inoculum, colonic digestion of beef resulted in significantly higher concentrations of the NOC-specific DNA adduct O(6)-carboxymethyl-guanine compared to chicken and pork, whereas nitrite curing had no significant effect. This study confirms previously reported evidence that heme-Fe is involved in the epidemiological association between red meat consumption and colorectal cancer, but questions the role of nitrite curing in this association.

  16. Fat Content and Nitrite-Curing Influence the Formation of Oxidation Products and NOC-Specific DNA Adducts during In Vitro Digestion of Meat

    Science.gov (United States)

    Van Hecke, Thomas; Vossen, Els; Vanden Bussche, Julie; Raes, Katleen; Vanhaecke, Lynn; De Smet, Stefaan

    2014-01-01

    The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes), protein oxidation products (protein carbonyl compounds) and NOC-specific DNA adducts (O6-carboxy-methylguanine) during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption and colorectal cancer risk. Digestion of uncured pork to which fat was added (total fat content 5 or 20%), resulted in significantly higher lipid and protein oxidation in the mimicked duodenal and colonic fluids, compared to digestion of pork without added fat (1% fat). A higher fat content also significantly favored the formation of O6-carboxy-methylguanine in the colon. Nitrite-curing of meat resulted in significantly lower lipid and protein oxidation before and after digestion, while an inconsistent effect on the formation of O6-carboxy-methylguanine was observed. The presented results demonstrate that haem-Fe is not solely responsible for oxidation and nitrosation reactions throughout an in vitro digestion approach but its effect is promoted by a higher fat content in meat. PMID:24978825

  17. Fat content and nitrite-curing influence the formation of oxidation products and NOC-specific DNA adducts during in vitro digestion of meat.

    Directory of Open Access Journals (Sweden)

    Thomas Van Hecke

    Full Text Available The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes, protein oxidation products (protein carbonyl compounds and NOC-specific DNA adducts (O6-carboxy-methylguanine during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption and colorectal cancer risk. Digestion of uncured pork to which fat was added (total fat content 5 or 20%, resulted in significantly higher lipid and protein oxidation in the mimicked duodenal and colonic fluids, compared to digestion of pork without added fat (1% fat. A higher fat content also significantly favored the formation of O6-carboxy-methylguanine in the colon. Nitrite-curing of meat resulted in significantly lower lipid and protein oxidation before and after digestion, while an inconsistent effect on the formation of O6-carboxy-methylguanine was observed. The presented results demonstrate that haem-Fe is not solely responsible for oxidation and nitrosation reactions throughout an in vitro digestion approach but its effect is promoted by a higher fat content in meat.

  18. Significant interactions between maternal PAH exposure and haplotypes in candidate genes on B[a]P-DNA adducts in a NYC cohort of non-smoking African-American and Dominican mothers and newborns.

    Science.gov (United States)

    Iyer, Shoba; Perera, Frederica; Zhang, Bingzhi; Chanock, Stephen; Wang, Shuang; Tang, Deliang

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAH) are a class of chemicals common in the environment. Certain PAH are carcinogenic, although the degree to which genetic variation influences susceptibility to carcinogenic PAH remains unclear. Also unknown is the influence of genetic variation on the procarcinogenic effect of in utero exposures to PAH. Benzo[a]pyrene (B[a]P) is a well-studied PAH that is classified as a probable human carcinogen. Within our New York City-based cohort, we explored interactions between maternal exposure to airborne PAH during pregnancy and maternal and newborn haplotypes (and in one case, a single-nucleotide polymorphism) in key B[a]P metabolism genes on B[a]P-DNA adducts in paired cord blood samples. The study subjects included non-smoking African-American (n = 132) and Dominican (n = 235) women with available data on maternal PAH exposure, paired cord adducts and genetic data who resided in the Washington Heights, Central Harlem and South Bronx neighborhoods of New York City. We selected seven maternal and newborn genes related to B[a]P metabolism, detoxification and repair for our analyses: CYP1A1, CYP1A2, CYP1B1, GSTM3, GSTT2, NQO1 and XRCC1. We found significant interactions between maternal PAH exposure and haplotype on cord B[a]P-DNA adducts in the following genes: maternal CYP1B1, XRCC1 and GSTM3, and newborn CYP1A2 and XRCC1 in African-Americans; and maternal XRCC1 and newborn NQO1 in Dominicans. These novel findings highlight differences in maternal and newborn genetic contributions to B[a]P-DNA adduct formation, as well as ethnic differences in gene-environment interactions, and have the potential to identify at-risk subpopulations who are susceptible to the carcinogenic potential of B[a]P.

  19. Dynamics and mechanism of UV-damaged DNA repair in indole-thymine dimer adduct: molecular origin of low repair quantum efficiency.

    Science.gov (United States)

    Guo, Xunmin; Liu, Zheyun; Song, Qinhua; Wang, Lijuan; Zhong, Dongping

    2015-02-26

    Many biomimetic chemical systems for repair of UV-damaged DNA showed very low repair efficiency, and the molecular origin is still unknown. Here, we report our systematic characterization of the repair dynamics of a model compound of indole-thymine dimer adduct in three solvents with different polarity. By resolving all elementary steps including three electron-transfer processes and two bond-breaking and bond-formation dynamics with femtosecond resolution, we observed the slow electron injection in 580 ps in water, 4 ns in acetonitrile, and 1.38 ns in dioxane, the fast back electron transfer without repair in 120, 150, and 180 ps, and the slow bond splitting in 550 ps, 1.9 ns, and 4.5 ns, respectively. The dimer bond cleavage is clearly accelerated by the solvent polarity. By comparing with the biological repair machine photolyase with a slow back electron transfer (2.4 ns) and a fast bond cleavage (90 ps), the low repair efficiency in the biomimetic system is mainly determined by the fast back electron transfer and slow bond breakage. We also found that the model system exists in a dynamic heterogeneous C-clamped conformation, leading to a stretched dynamic behavior. In water, we even identified another stacked form with ultrafast cyclic electron transfer, significantly reducing the repair efficiency. Thus, the comparison of the repair efficiency in different solvents is complicated and should be cautious, and only the dynamics by resolving all elementary steps can finally determine the total repair efficiency. Finally, we use the Marcus electron-transfer theory to analyze all electron-transfer reactions and rationalize all observed electron-transfer dynamics.

  20. A Stable Isotope Dilution Nanoflow Liquid Chromatography Tandem Mass Spectrometry Assay for the Simultaneous Detection and Quantification of Glyoxal-Induced DNA Cross-Linked Adducts in Leukocytes from Diabetic Patients.

    Science.gov (United States)

    Chen, Hauh-Jyun Candy; Chang, Ya-Lang; Teng, Yi-Chun; Hsiao, Chiung-Fong; Lin, Tsai-Shiuan

    2017-12-19

    Glyoxal (gx) is a bifunctional electrophile capable of cross-linking DNA. Although it is present in foods and from the environment, endogenous formation of glyoxal occurs through metabolism of carbohydrates and oxidation of lipids and nucleic acids. Plasma concentrations of glyoxal are elevated in in diabetes mellitus patients compared to nondiabetics. The most abundant 2'-deoxyribonucleoside adducts cross-linked by glyoxal are dG-gx-dC, dG-gx-dA, and dG-gx-dG. These DNA cross-links can be mutagenic by damaging the integrity of the DNA structure. Herein, we developed a highly sensitive and specific assay for the simultaneous detection and quantification of the dG-gx-dC and dG-gx-dA cross-links based on stable isotope dilution (SID) nanoflow liquid chromatography nanospray ionization tandem mass spectrometry (nanoLC-NSI/MS/MS) under the highly selected reaction monitoring mode and using a triple quadrupole mass spectrometer. The entire assay procedure involved addition of the stable isotope standards [15N5]dG-gx-dC and [15N5]dG-gx-dA as internal standards, enzyme hydrolysis to release the cross-links as nucleosides, enrichment by a reversed-phase solid-phase extraction column, and nanoLC-NSI/MS/MS analysis. The detection limit is 0.19 amol for dG-gx-dC and 0.89 amol for dG-gx-dA, which is 400 and 80 times more sensitive, respectively, than capillary LC-NSI/MS/MS assay of these adducts. The lower limit of quantification was 94 and 90 amol for dG-gx-dC and dG-gx-dA, respectively, which is equivalent to 0.056 and 0.065 adducts in 108 normal nucleotides in 50 μg of DNA. In type 2 diabetes mellitus (T2DM) patients (n = 38), the levels of dG-gx-dC and dG-gx-dA in leukocyte DNA were 1.94 ± 1.20 and 2.10 ± 1.77 in 108 normal nucleotides, respectively, which were significantly higher than those in nondiabetics (n = 39: 0.83 ± 0.92 and 1.05 ± 0.99 in 108 normal nucleotides, respectively). Excluding the factor of smoking, an exogenous source of glyoxal, levels of these

  1. Effect of increased intake of dietary animal fat and fat energy on oxidative damage, mutation frequency, DNA adduct level and DNA repair in rat colon and liver

    DEFF Research Database (Denmark)

    Vogel, Ulla Birgitte; Danesvar, B.; Autrup, H.

    2003-01-01

    The effect of high dietary intake of animal fat and an increased fat energy intake on colon and liver genotoxicity and on markers of oxidative damage and antioxidative defence in colon, liver and plasma was investigated in Big Blue rats. The rats were fed ad libitum with semi-synthetic feed...... supplemented with 0, 3, 10 or 30% w/w lard. After 3 weeks, the mutation frequency, DNA repair gene expression, DNA damage and oxidative markers were determined in liver, colon and plasma. The mutation frequency of the lambda gene cII did not increase with increased fat or energy intake in colon or liver......, colon, or urine. Thus, lard intake at the expense of other nutrients and a large increase in the fat energy consumption affects the redox state locally in the liver cytosol, but does not induce DNA-damage, systemic oxidative stress or a dose-dependent increase in mutation frequency in rat colon or liver....

  2. Base-displaced intercalation of the 2-amino-3-methylimidazo[4,5-f]quinolone N2-dG adduct in the NarI DNA recognition sequence.

    Science.gov (United States)

    Stavros, Kallie M; Hawkins, Edward K; Rizzo, Carmelo J; Stone, Michael P

    2014-03-01

    2-Amino-3-methylimidazo[4,5-f]quinolone (IQ), a heterocyclic amine found in cooked meats, undergoes bioactivation to a nitrenium ion, which alkylates guanines at both the C8-dG and N2-dG positions. The conformation of a site-specific N2-dG-IQ adduct in an oligodeoxynucleotide duplex containing the iterated CG repeat restriction site of the NarI endonuclease has been determined. The IQ moiety intercalates, with the IQ H4a and CH3 protons facing the minor groove, and the IQ H7a, H8a and H9a protons facing the major groove. The adducted dG maintains the anti-conformation about the glycosyl bond. The complementary dC is extruded into the major groove. The duplex maintains its thermal stability, which is attributed to stacking between the IQ moiety and the 5'- and 3'-neighboring base pairs. This conformation is compared to that of the C8-dG-IQ adduct in the same sequence, which also formed a 'base-displaced intercalated' conformation. However, the C8-dG-IQ adopted the syn conformation placing the Watson-Crick edge of the modified dG into the major groove. In addition, the C8-dG-IQ adduct was oriented with the IQ CH3 group and H4a and H5a facing the major groove. These differences may lead to differential processing during DNA repair and replication.

  3. The Impact of Glucuronidation on the Bioactivation and DNA Adduction of the Cooked-Food Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b] pyridine in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M A; Ubick, E A; Felton, J S

    2005-03-31

    UDP-glucuronosyltransferases (UGTs) catalyze the glucuronidation of many different chemicals. Glucuronidation is especially important for detoxifying reactive intermediates from metabolic reactions, which otherwise can be biotransformed into highly reactive cytotoxic or carcinogenic species. Detoxification of certain food-borne carcinogenic heterocyclic amines (HAs) is highly dependent on UGT1A-mediated glucuronidation. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most mass abundant carcinogenic HA found in well-done cooked meat, is extensively glucuronidated by UGT1A proteins. In humans, CYP1A2 catalyzed N-hydroxylation and subsequent UGT1A-mediated glucuronidation is a dominant pathway in the metabolism of PhIP. Therefore, changes in glucuronidation rates could significantly alter PhIP metabolism. To determine the importance of UGT1A-mediated glucuronidation in the biotransformation of PhIP, UGT1A proficient Wistar and UGT1A deficient Gunn rats were exposed to a single 100 {micro}g/kg oral dose of [{sup 14}C]-PhIP. Urine was collected over 24 h and the PhIP urinary metabolite profiles were compared between the two strains. After the 24 h exposure, livers and colon were removed and analyzed for DNA adduct formation by accelerator mass spectrometry. Wistar rats produced several PhIP and N-hydroxy-PhIP glucuronides that accounted for {approx}25% of the total amount of recovered urinary metabolites. In the Gunn rats, PhIP and N-hydroxy-PhIP glucuronides were reduced by 68-92%, compared to the Wistar rats, and comprised only 4% of the total amount of recovered urinary metabolites. PhIP-DNA adduct analysis from the Gunn rats revealed a correlation between reduced PhIP and N-hydroxy-PhIP glucuronide levels in the urine and increased hepatic DNA adducts, compared to the Wistar rats. These results indicate that UGT1A-mediated glucuronidation of PhIP and N-hydroxy-PhIP is an important pathway for PhIP detoxification. Failure to form glucuronide conjugates

  4. Methods for retrospective detection of exposure to toxic scheduled chemicals. Part B: Mass spectrometric and immunochemical analysis of covalent adducts to proteins and DNA

    NARCIS (Netherlands)

    Noort, D.; Black, R.M.

    2012-01-01

    In this article, an overview of themethods that are currently available for retrospective detection of exposure to a number of chemical warfare agents (CWA), based on adducts formed with macromolecules such as proteins, is presented. These methods can be applied for various purposes, e.g. diagnosis

  5. Probing for DNA damage with β-hairpins: Similarities in incision efficiencies of bulky DNA adducts by prokaryotic and human nucleotide excision repair systems in vitro

    Science.gov (United States)

    Liu, Yang; Reeves, Dara; Kropachev, Konstantin; Cai, Yuqin; Ding, Shuang; Kolbanovskiy, Marina; Kolbanovskiy, Alexander; Bolton, Judith L.; Broyde, Suse; Van Houten, Bennett; Geacintov, Nicholas E.

    2011-01-01

    Nucleotide excision repair (NER) is an important prokaryotic and eukaryotic defense mechanism that removes a large variety of structurally distinct lesions in cellular DNA. While the proteins involved are completely different, the mode of action of these two repair systems is similar, involving a cut-and-patch mechanism in which an oligonucleotide sequence containing the lesion is excised. The prokaryotic and eukaryotic NER damage-recognition factors have common structural features of β-hairpin intrusion between the two DNA strands at the site of the lesion. In the present study, we explored the hypothesis that this common β-hairpin intrusion motif is mirrored in parallel NER incision efficiencies in the two systems. We have utilized human HeLa cell extracts and the prokaryotic UvrABC proteins to determine their relative NER incision efficiencies. We report here comparisons of relative NER efficiencies with a set of stereoisomeric DNA lesions derived from metabolites of benzo[a]pyrene and equine estrogens in different sequence contexts, utilizing 21 samples. We found a general qualitative trend towards similar relative NER incision efficiencies for ~ 65% of these substrates; the other cases deviate mostly by ~ 30% or less from a perfect correlation, although several more distant outliers are also evident. This resemblance is consistent with the hypothesis that lesion recognition through β-hairpin insertion, a common feature of the two systems, is facilitated by local thermodynamic destabilization induced by the lesions in both cases. In the case of the UvrABC system, varying the nature of the UvrC endonuclease, while maintaining the same UvrA/B proteins, can markedly affect the relative incision efficiencies. These observations suggest that, in addition to recognition involving the initial modified duplexes, downstream events involving UvrC can also play a role in distinguishing and processing different lesions in prokaryotic NER. PMID:21741328

  6. Ethanol and 4-methylpyrazole increase DNA adduct formation of furfuryl alcohol in FVB/N wild-type mice and in mice expressing human sulfotransferases 1A1/1A2.

    Science.gov (United States)

    Sachse, Benjamin; Meinl, Walter; Glatt, Hansruedi; Monien, Bernhard H

    2016-03-01

    Furfuryl alcohol (FFA) is a carcinogenic food contaminant, which is formed by acid- and heat-catalyzed degradation of fructose and glucose. The activation by sulfotransferases (SULTs) yields a DNA reactive and mutagenic sulfate ester. The most prominent DNA adduct, N(2)-((furan-2-yl)methyl)-2'-deoxyguanosine (N(2)-MF-dG), was detected in FFA-treated mice and also in human tissue samples. The dominant pathway of FFA detoxification is the oxidation via alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs). The activity of these enzymes may be greatly altered in the presence of inhibitors or competitive substrates. Here, we investigated the impact of ethanol and the ADH inhibitor 4-methylpyrazole (4MP) on the DNA adduct formation by FFA in wild-type and in humanized mice that were transgenic for human SULT1A1/1A2 and deficient in the mouse (m) Sult1a1 and Sult1d1 genes (h1A1/1A2/1a1(-)/1d1(-)). The administration of FFA alone led to hepatic adduct levels of 4.5 N(2)-MF-dG/10(8) nucleosides and 33.6 N(2)-MF-dG/10(8) nucleosides in male and female wild-type mice, respectively, and of 19.6 N(2)-MF-dG/10(8) nucleosides and 95.4 N(2)-MF-dG/10(8) nucleosides in male and female h1A1/1A2/1a1(-)/1d1(-) mice. The coadministration of 1.6g ethanol/kg body weight increased N(2)-MF-dG levels by 2.3-fold in male and by 1.7-fold in female wild-type mice and by 2.5-fold in male and by 1.5-fold in female h1A1/1A2/1a1(-)/1d1(-) mice. The coadministration of 100mg 4MP/kg body weight had a similar effect on the adduct levels. These findings indicate that modulators of the oxidative metabolism, e.g. the drug 4MP or consumption of alcoholic beverages, may increase the genotoxic effects of FFA also in humans. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Assessment of the bioavailability of PAHs in rats exposed to a polluted soil by natural routes: Induction of EROD activity and DNA adducts and PAH burden in both liver and lung

    Energy Technology Data Exchange (ETDEWEB)

    Fouchecourt, M.O.; Riviere, J.L. [INRA-DGER, Marcy l`Etoile (France). Unite Associee de Toxicologie Metabolique et Ecotoxicologie; Arnold, M.; Rether, B. [IUT Louis Pasteur, Schiltigheim (France). Lab. de Biologie Vegetale Appliquee; Berny, P.; Videmann, B. [Ecole Nationale Veterinaire de Lyon, Marcy l`Etoile (France). Lab. de Toxicologie Veterinaire

    1999-05-01

    In order to assess bioavailability of polycyclic aromatic hydrocarbons (PAHs) present in soils, male laboratory rats were exposed to litters of control and polluted soils. After 88 {+-} 2 h of exposure, several biomarkers were measured in both liver and lung. When rats were exposed to SIV soil, contaminated by a mixture of at least 13 PAHs, (1) only 2 or 3 PAH compounds were detected in liver and lung; (2) cytochrome P450-dependent monooxygenase activity, followed by 7-ethoxyresorufin O-deethylase (EROD) activity measurement, was highly induced in liver (13-fold-induction) and lung (up to 78-fold); and (3) DNA adducts were significantly increased. For what concerns soil artificially contaminated by only one PAH (phenanthrene or B[a]P), EROD activity was not or slightly induced, respectively. These results demonstrate the occurrence of a high bioavailability of PAHs to mammals in natural conditions of exposure. First results concerning DNA adducts must be proved, but they already show that a short exposure of mammals to PAH-polluted soils can lead to potential genotoxic effects. EROD activity can be used as a sensitive biomarker in both liver and lung of rats maintained on litters of soils in the laboratory, and such a test can be used routinely to contribute to risk assessment.

  8. The study of DNA adduct 8-hydroxy-2‧deoxyguanosine (8-OHdG) formation of butylated hydroxyanisole (BHA) and its metabolite ter-butyl hydroquinone (TBHQ) through in vitro reaction with Calf Thymus DNA and 2‧deoxyguanosine

    Science.gov (United States)

    Budiawan; Purwaningsih, S. S.; Cahaya, D. I.

    2017-04-01

    Butylated Hydroxyanisole (BHA) and its metabolite Tert-Butyl Hydroquinone (TBHQ) are synthetic antioxidants, commonly used as food and beverage preservatives. Although WHO declared their safety, the use of these preservatives are still controversial because some studies showed that BHA induced proliferative effects in animal testing and TBHQ is considered as carcinogenic and causes DNA cleavage. This study is aimed to analyze the interaction between Calf Thymus DNA with BHA and TBHQ which are mediated with Copper (II) Chloride. The result of the study in spectrophotometric showed there was bathochromic shift as much as 2-3 nm in DNA treated with TBHQ. The next analysis used HPLC method in stationary phase of ODS, mobile phase of 10mM Natrium Hydrogen Phosphate Buffer and Methanol (85 : 15) for DNA adduct formation, 8-Hydroxy-2-Deoxyguanosine (8-OHDG) as biomarker of risk cancer. The resultof the study showed the formation of DNA adduct 8-OHDG in the interaction between DNA and 20-500 ppm of TBHQ. The 8-OHdG formation was greatly increased by the higher concentration of TBHQ. The relative amount of 8 OHDG which formed was reached 946/105 deoxyguanosine in DNA bases. Confirmation test by LCMS/MS was characterized with the detection of mother ion peak (m/z 284); fragment ion peaks at m/z 167.9, and 139.9; at retention time 3.52 min. Meanwhile the interaction between DNA and 50-250 ppm BHA did not induce 8-OHDG.

  9. Sustained induction of cytochrome P4501A1 in human hepatoma cells by co-exposure to benzo[a]pyrene and 7H-dibenzo[c,g]carbazole underlies the synergistic effects on DNA adduct formation

    Energy Technology Data Exchange (ETDEWEB)

    Gábelová, Alena, E-mail: alena.gabelova@savba.sk [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Poláková, Veronika [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Prochazka, Gabriela [Department of Biosciences and Nutrition, Karolinska Institute, Novum, SE-141 83 Huddinge (Sweden); Department of Medical Epidemiology and Biostatistics, Karolinska Institute, SE-171 77 Stockholm (Sweden); Kretová, Miroslava; Poloncová, Katarína; Regendová, Eva; Luciaková, Katarína [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Segerbäck, Dan [Department of Biosciences and Nutrition, Karolinska Institute, Novum, SE-141 83 Huddinge (Sweden)

    2013-08-15

    To gain a deeper insight into the potential interactions between individual aromatic hydrocarbons in a mixture, several benzo[a]pyrene (B[a]P) and 7H-dibenzo[c,g]carbazole (DBC) binary mixtures were studied. The biological activity of the binary mixtures was investigated in the HepG2 and WB-F344 liver cell lines and the Chinese hamster V79 cell line that stably expresses the human cytochrome P4501A1 (hCYP1A1). In the V79 cells, binary mixtures, in contrast to individual carcinogens, caused a significant decrease in the levels of micronuclei, DNA adducts and gene mutations, but not in cell survival. Similarly, a lower frequency of micronuclei and levels of DNA adducts were found in rat liver WB-F344 cells treated with a binary mixture, regardless of the exposure time. The observed antagonism between B[a]P and DBC may be due to an inhibition of Cyp1a1 expression because cells exposed to B[a]P:DBC showed a decrease in Cyp1a1 mRNA levels. In human liver HepG2 cells exposed to binary mixtures for 2 h, a reduction in micronuclei frequency was also found. However, after a 24 h treatment, synergism between B[a]P and DBC was determined based on DNA adduct formation. Accordingly, the up-regulation of CYP1A1 expression was detected in HepG2 cells exposed to B[a]P:DBC. Our results show significant differences in the response of human and rat cells to B[a]P:DBC mixtures and stress the need to use multiple experimental systems when evaluating the potential risk of environmental pollutants. Our data also indicate that an increased expression of CYP1A1 results in a synergistic effect of B[a]P and DBC in human cells. As humans are exposed to a plethora of noxious chemicals, our results have important implications for human carcinogenesis. - Highlights: • B[a]P:DBC mixtures were less genotoxic in V79MZh1A1 cells than B[a]P and DBC alone. • An antagonism between B[a]P and DBC was determined in rat liver WB-F344 cells. • The inhibition of CYP1a1 expression by B[a]P:DBC mixture

  10. Radiosensitization of DNA by Cisplatin Adducts Results from an Increase in the Rate Constant for the Reaction with Hydrated Electrons and Formation of Pt(I).

    Science.gov (United States)

    Behmand, B; Marignier, J-L; Mostafavi, M; Wagner, J R; Hunting, D J; Sanche, L

    2015-07-30

    Pulse radiolysis measurements of the decay of hydrated electrons in solutions containing different concentrations of the oligonucleotide GTG with and without a cisplatin adduct show that the presence of a cisplatin moiety accelerates the reaction between hydrated electrons and the oligonucleotide. The rate constant of the reaction is found to be 2.23 × 10(10) mol(-1) L s(-1), which indicates that it is diffusion controlled. In addition, we show for the first time the formation of a Pt(I) intermediate as a result of the reaction of hydrated electrons with GTG-cisplatin. A putative reaction mechanism is proposed, which may form the basis of the radiosensitization of cancer cells in concomitant chemoradiation therapy with cisplatin.

  11. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse

    Energy Technology Data Exchange (ETDEWEB)

    Siddens, Lisbeth K. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Bunde, Kristi L. [College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331 (United States); Harper, Tod A. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); McQuistan, Tammie J. [Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); Löhr, Christiane V. [Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331 (United States); Bramer, Lisa M. [Applied Statistics and Computational Modeling, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Waters, Katrina M. [Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Tilton, Susan C. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Krueger, Sharon K. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); and others

    2015-09-01

    FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.

  12. Implication of the E. coli K12 uvrA and recA genes in the repair of 8-methoxypsoralen-induced mono adducts and crosslinks on plasmid DNA; Implicacion de los genes uvrA de E. coli K12 en la reparacion de monoaductos y entrecruzamien tos inducidos en DNA plasmidico por 8-metoxipso raleno mas luz ultravioleta A

    Energy Technology Data Exchange (ETDEWEB)

    Paramio, J.M.; Bauluz, C.; Vidania, R. de

    1986-07-01

    Genotoxicity of psoralen damages on plasmid DNA has been studied. pBR322 DNA was randomly modified with several concentrations of 8-methoxypsoralen plus 365 nm-UV light. After transformation into E. coli strains (wild-type, uvrA and recA) plasmid survival and mutagenesis were analyzed. To study the influence of the SOS response on plasmid recovery, preirradiation of the cells was performed. In absence of cell preirradiation, crosslinks were not repaired in any strain. Mono adducts were also lethal but in part removed by the excision-repair pathway. Preirradiation of the cells significantly. increased plasmid recovery in recA+ celia. In uvrA- only the mutagenic pathway seemed to be involved in the repair of the damaged DNA. Wild type strain showed the highest increase in plasmid survival, involving the repair of mono adducts and some fraction of crosslinks mainly through an error-free repair pathway. This suggests an enhancement of the excision repair promoted by the induction of SOS functions. (Author) 32 refs.

  13. Acetaldehyde Adducts in Alcoholic Liver Disease

    Directory of Open Access Journals (Sweden)

    Mashiko Setshedi

    2010-01-01

    Full Text Available Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD, with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC. Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2–15% versus cirrhosis (15–20% is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.

  14. Relation between benzo[a]pyrene-DNA adducts, cell proliferation and p53 expression in tracheal epithelium of hamsters fed a high B-carotene diet

    NARCIS (Netherlands)

    Wolterbeek, A.P.M.; Roggeband, R.; Baan, R.A.; Feron, V.J.; Rutten, A.A.J.J.L.

    1995-01-01

    Vitamin A and β-carotene protect against respiratory tract cancer by inhibiting the formation of DNA damage and controlling cellular proliferation and differentiation, Recently, it has been shown that the p53 tumor-suppressor gene plays a crucial role in the etiology of respiratory tract cancer. In

  15. 2'-Deoxythymidine Adducts from the Anti-HIV Drug Nevirapine

    Directory of Open Access Journals (Sweden)

    M. Matilde Marques

    2013-04-01

    Full Text Available Nevirapine (NVP is a non-nucleoside reverse transcriptase inhibitor (NNRTI used against HIV-1. Currently, NVP is the most widely used anti-HIV drug in developing countries, both in combination therapy and to prevent mother-to-child transmission of HIV. Despite its efficacy against HIV, NVP produces a variety of toxic responses, including hepatotoxicity and skin rash. It is also associated with increased incidences of hepatoneoplasias in rodents. In addition, epidemiological data suggest that NNRTI use is a risk factor for non-AIDS-defining cancers in HIV-positive patients. Current evidence supports the involvement of metabolic activation to reactive electrophiles in NVP toxicity. NVP metabolism includes oxidation to 12-hydroxy-NVP; subsequent Phase II sulfonation produces an electrophilic metabolite, 12-sulfoxy-NVP, capable of reacting with DNA to yield covalent adducts. Since 2’-deoxythymidine (dT adducts from several alkylating agents are regarded as having significant mutagenic/carcinogenic potential, we investigated the formation of NVP-dT adducts under biomimetic conditions. Toward this goal, we initially prepared and characterized synthetic NVP-dT adduct standards using a palladium-mediated Buchwald-Hartwig coupling strategy. The synthetic standards enabled the identification, by LC-ESI-MS, of 12-(2'-deoxythymidin-N3-yl-nevirapine (N3-NVP-dT in the enzymatic hydrolysate of salmon testis DNA reacted with 12-mesyloxy-NVP, a synthetic surrogate for 12-sulfoxy-NVP. N3-NVP-dT, a potentially cytotoxic and mutagenic DNA lesion, was also the only dT-specific adduct detected upon reaction of dT with 12-mesyloxy-NVP. Our data suggest that N3-NVP-dT may be formed in vivo and play a role in the hepatotoxicity and/or putative hepatocarcinogenicity of NVP.

  16. Translesion DNA Synthesis by Human DNA Polymerase ? on Templates Containing a Pyrimidopurinone Deoxyguanosine Adduct, 3-(2?-Deoxy-?-d-erythro-pentofuranosyl)pyrimido-[1,2-a]purin-10(3H)-one?

    OpenAIRE

    Stafford, Jennifer B.; Eoff, Robert L.; Kozekova, Albena; Rizzo, Carmelo J.; Guengerich, F. Peter; Marnett, Lawrence J.

    2008-01-01

    M1dG (3-(2?-deoxy-?-d-erythro-pentofuranosyl)pyrimido[1,2-a]purin-10(3H)-one) lesions are mutagenic in bacterial and mammalian cells, leading to base substitutions (mostly M1dG to dT and M1dG to dA) and frameshift mutations. M1dG is produced endogenously through the reaction of peroxidation products, base propenal or malondialdehyde, with deoxyguanosine residues in DNA. The mutagenicity of M1dG in Escherichia coli is dependent on the SOS response, specifically the umuC and umuD gene products,...

  17. Bilateral failure of adduction following orbital decompression.

    Science.gov (United States)

    Kinsella, F; Kyle, P; Stansfield, A

    1990-01-01

    We report a case of bilateral complete failure of adduction following bilateral translid antralethmoidal orbital decompression. We believe the probable mechanism is neuropraxia (temporary dysfunction) of the third cranial nerves' supply to the medial recti, owing to these nerves' occupying an anatomically abnormal position. Partial recovery of adduction occurred over the ensuing six months. Images PMID:2337551

  18. Redshift or adduct stabilization -- a computational study of hydrogen bonding in adducts of protonated carboxylic acids

    DEFF Research Database (Denmark)

    Olesen, Solveig Gaarn; Hammerum, Steen

    2009-01-01

    changes and the redshift favor the Z OH group, matching the results of NBO and AIM calculations. This reflects that the thermochemistry of adduct formation is not a good measure of the hydrogen bond strength in charged adducts, and that the ionic interactions in the E and Z adducts of protonated......It is generally expected that the hydrogen bond strength in a D-H-A adduct is predicted by the difference between the proton affinities of D and A, measured by the adduct stabilization, and demonstrated by the IR redshift of the D-H bond stretching vibrational frequency. These criteria do...... not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The delta-PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length...

  19. Diagnosing human exposure to sulfur mustard by measuring human serum albumin adducts via isotope dilution tandem mass spectrometry (Poster)

    NARCIS (Netherlands)

    Andacht, T.M.; Blake, T.A.; Noort, D.; Johnson, R.C.

    2012-01-01

    Sulfur mustard agent (HD) (2,2’-dichloroethyl sulfide) is a reactive electrophile that readily alkylates aromatic nitrogen atoms, carboxyl groups, sulfides, and sulfhydryl groups on DNA and protein. Adducts to both DNA and specific proteins have been used to assess human exposure to HD. Human serum

  20. Site-specific synthesis of oligonucleotides containing malondialdehyde adducts of deoxyguanosine and deoxyadenosine via a postsynthetic modification strategy.

    Science.gov (United States)

    Wang, Hao; Kozekov, Ivan D; Kozekova, Albena; Tamura, Pamela J; Marnett, Lawrence J; Harris, Thomas M; Rizzo, Carmelo J

    2006-11-01

    Malondialdehyde (MDA) and its reactive equivalent, base propenal, are products of oxidative damage to lipids and DNA, respectively; they are mutagenic in bacterial and mammalian systems, and MDA is carcinogenic in rats. MDA adducts of deoxyguanosine (M1dG), deoxyadenosine (OPdA), and deoxycytidine (OPdC) have been characterized. We have developed site-specific syntheses of M1dG and OPdA adducted oligonucleotides that rely on a postsynthetic modification strategy. This work provides an alternative route to the M1dG adducted oligonucleotide and, to date, the only viable strategy for the site-specific synthesis of OPdA-modified oligonucleotides. The stability of the modified oligonucleotides was examined by UV thermal melting studies (Tm). In contrast to the M1dG adduct, OPdA caused very little change in the Tm.

  1. Site-specific synthesis of oligonucleotides containing malondialdehyde adducts of deoxyguanosine and deoxyadenosine via a post-synthetic modification strategy

    Science.gov (United States)

    Wang, Hao; Kozekov, Ivan D.; Kozekova, Albena; Tamura, Pamela; Marnett, Lawrence J.; Harris, Thomas M.; Rizzo, Carmelo J.

    2008-01-01

    Malondialdehyde (MDA) and its reactive equivalent, base propenal, are products of oxidative damage to lipids and DNA, respectively; they are mutagenic in bacterial and mammalian systems and MDA is carcinogenic in rats. MDA adducts of deoxyguanosine (M1dG), deoxyadenosine (OPdA) and deoxycytidine (OPdC) have been characterized. We have developed site-specific syntheses of M1dG and OPdA adducted oligonucleotides that rely on a post-synthetic modification strategy. This work provides an alternative route to the M1dG adducted oligonucleotide and to date, the only viable strategy for the site-specific synthesis of OPdA modified oligonucleotides. The stability of the modified oligonucleotides was examined by UV thermal melting studies (Tm). In contrast to the M1dG adduct, OPdA caused very little change in the Tm. PMID:17112234

  2. O6-pyridyloxobutylguanine adducts contribute to the mutagenic properties of pyridyloxobutylating agents.

    Science.gov (United States)

    Mijal, Renée S; Loktionova, Natalia A; Vu, Choua C; Pegg, Anthony E; Peterson, Lisa A

    2005-10-01

    The tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) are potent carcinogens in animal models and likely human carcinogens. Both NNK and NNN can be activated to a pyridyloxobutylating agent. This alkylating agent contributes to the carcinogenic effects of NNK and NNN via the formation of miscoding DNA adducts. One of these adducts, O6-[4-oxo-4-(3-pyridyl)butyl]guanine (O6-pobG) has been characterized as a mutagenic adduct which is a substrate for the repair protein O6-alkylguanine-DNA alkyltransferase (AGT). Repair of O6-alkylguanine adducts by AGT protects cells from the mutagenic and carcinogenic effects of alkylating agents and is likely to play a similar role in shielding cells from the adverse effects of pyridyloxobutylating agents. Therefore, we examined the mutagenicity of the model pyridyloxobutylating agent, 4-(acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (NNKOAc), in Salmonella typhimurium YG7108 expressing hAGT. Expression of hAGT protected cells from NNKOAc-induced mutagenicity. Interestingly, hAGT did not shield cells from the toxicity of this agent. To confirm that the repair of O6-pobG was increased in the bacteria expressing hAGT, we measured levels of this adduct in NNKOAc-treated cultures. The levels of O6-pobG were lower in DNA from bacteria expressing hAGT. This work establishes an important role for O6-pobG in mediating the mutagenic, and possibly carcinogenic, effects of pyridyloxobutylating compounds.

  3. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....

  4. Site-specific synthesis of oligonucleotides containing malondialdehyde adducts of deoxyguanosine and deoxyadenosine via a post-synthetic modification strategy

    OpenAIRE

    Wang, Hao; Kozekov, Ivan D.; Kozekova, Albena; Tamura, Pamela; Marnett, Lawrence J.; Harris, Thomas M.; Rizzo, Carmelo J.

    2006-01-01

    Malondialdehyde (MDA) and its reactive equivalent, base propenal, are products of oxidative damage to lipids and DNA, respectively; they are mutagenic in bacterial and mammalian systems and MDA is carcinogenic in rats. MDA adducts of deoxyguanosine (M1dG), deoxyadenosine (OPdA) and deoxycytidine (OPdC) have been characterized. We have developed site-specific syntheses of M1dG and OPdA adducted oligonucleotides that rely on a post-synthetic modification strategy. This work provides an alternat...

  5. What predicts the first peak of the knee adduction moment?

    Science.gov (United States)

    Schmitz, Anne; Noehren, Brian

    2014-01-01

    Introduction The first peak of the knee adduction moment curve during walking has been shown to be a good clinical surrogate measure of medial tibiofemoral joint loading and osteoarthritis. Defining the relative contributions of the variables that dictate the knee adduction moment, such as center of mass, center of pressure, vertical ground reaction force, and knee adduction angle (i.e. lower limb alignment), has not been formally investigated within the same cohort of individuals. Purpose Therefore, the goal of this study was to determine which of these variables is the biggest determinant of the first peak of knee adduction moment curve. Methods Instrumented gait analysis was collected for 30 individuals. Variables significantly correlated with the peak knee adduction moment were input into a stepwise multi-variable linear regression model. Results The knee adduction angle predicted 58% of the variance in the first peak knee adduction moment and the vertical ground reaction force magnitude predicted the second most variance (20%). Conclusions The most effective way to modify the peak knee adduction moment may be to change the knee adduction angle (e.g. offloader brace), followed by changing the vertical magnitude of the ground reaction force (e.g. cane use). PMID:25127390

  6. CARDIOSELECTIVE AND CUMULATIVE OXIDATION OF MITOCHONDRIAL DNA FOLLOWING SUBCHRONIC DOXORUBICIN ADMINISTRATION

    Science.gov (United States)

    We recently reported the preferential accumulation of 8-hydroxydeoxyguanosine (80HdG) adducts in cardiac mitrochondrial DNA (mDNA) following acute intoxication of rats with doxorubicin. The concentration of 80HdG adducts decreased to control values within 2 weeks. Since conventio...

  7. Including the Copenhagen Adduction Exercise in the FIFA 11+ Provides Missing Eccentric Hip Adduction Strength Effect in Male Soccer Players

    DEFF Research Database (Denmark)

    Harøy, Joar; Thorborg, Kristian; Serner, Andreas

    2017-01-01

    BACKGROUND: The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength. PURPOSE......: To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen adduction exercise. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: We recruited 45 eligible players from 2 U19 elite male soccer teams. Players were randomized...... into 2 groups; 1 group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+ but replaced the Nordic hamstring exercise with the Copenhagen adduction exercise. Both groups performed the intervention 3 times weekly for 8 weeks. Players completed eccentric strength and sprint...

  8. Prolonged Acetaminophen-Protein Adduct Elimination During Renal Failure, Lack of Adduct Removal by Hemodiafiltration, and Urinary Adduct Concentrations After Acetaminophen Overdose.

    Science.gov (United States)

    Curry, Steven C; Padilla-Jones, Angela; O'Connor, Ayrn D; Ruha, Anne-Michelle; Bikin, Dale S; Wilkins, Diana G; Rollins, Douglas E; Slawson, Matthew H; Gerkin, Richard D

    2015-06-01

    Elevated concentrations of serum acetaminophen-protein adducts, measured as protein-derived acetaminophen-cysteine (APAP-CYS), have been used to support a diagnosis of APAP-induced liver injury when histories and APAP levels are unhelpful. Adducts have been reported to undergo first-order elimination, with a terminal half-life of about 1.6 days. We wondered whether renal failure would affect APAP-CYS elimination half-life and whether continuous venovenous hemodiafiltration (CVVHDF), commonly used in liver failure patients, would remove adducts to lower their serum concentrations. Terminal elimination half-lives of serum APAP-CYS were compared between subjects with and without renal failure in a prospective cohort study of 168 adults who had ingested excessive doses of APAP. APAP-CYS concentrations were measured in plasma ultrafiltrate during CVVHDF at times of elevated serum adduct concentrations. Paired samples of urine and serum APAP-CYS concentrations were examined to help understand the potential importance of urinary elimination of serum adducts. APAP-CYS elimination half-life was longer in 15 renal failure subjects than in 28 subjects with normal renal function (41.3 ± 2.2 h versus 26.8 ± 1.1 h [mean ± SEM], respectively, p < 0.001). CVVHDF failed to remove detectable amounts of APAP-CYS in any of the nine subjects studied. Sixty-eight percent of 557 urine samples from 168 subjects contained no detectable APAP-CYS, despite levels in serum up to 16.99 μM. Terminal elimination half-life of serum APAP-CYS was prolonged in patients with renal failure for reasons unrelated to renal urinary adduct elimination, and consideration of prolonged elimination needs to be considered if attempting back-extrapolation of adduct concentrations. CVVHDF did not remove detectable APAP-CYS, suggesting approximate APAP-protein adduct molecular weights ≥ 50,000 Da. The presence of urinary APAP-CYS in the minority of instances was most compatible with renal

  9. Using lysine adducts of human serum albumin to investigate the disposition of exogenous formaldehyde in human blood.

    Science.gov (United States)

    Regazzoni, Luca G; Grigoryan, Hasmik; Ji, Zhiying; Chen, Xi; Daniels, Sarah I; Huang, Deyin; Sanchez, Sylvia; Tang, Naijun; Sillé, Fenna C M; Iavarone, Anthony T; Williams, Evan R; Zhang, Luoping; Rappaport, Stephen M

    2017-02-15

    Formaldehyde is a human carcinogen that readily binds to nucleophiles, including proteins and DNA. To investigate whether exogenous formaldehyde produces adducts in extracellular fluids, we characterized modifications to human serum albumin (HSA) following incubation of whole blood, plasma, and saliva with formaldehyde at concentrations of 1, 10 and 100μM. The only HSA locus that showed the presence of formaldehyde modifications was Lys199. A N(6)-Lys adduct with added mass of 12Da, representing a putative intramolecular crosslink, was detected in biological fluids that had been incubated with formaldehyde but not in control fluids. An adduct representing N(6)-Lys formylation was detected in all fluids, but levels did not increase above control values over the tested range of formaldehyde concentrations. An adduct representing N(6)-Lys199 acetylation was also measured in all samples. We then applied the assay to repeated samples of human plasma from 6 nonsmoking volunteer subjects (from Berkeley, CA), and single samples of serum from 15 workers exposed to airborne formaldehyde at about 1.5ppm in a production facility and 15 control workers from Tianjin, China. Although all human plasma/serum samples contained basal levels of the products of N(6)-Lys formylation and acetylation, the putative crosslink product was not detected. Since the putative crosslink was observed in plasma incubated with formaldehyde at 1μM, this suggests that the endogenous concentration of formaldehyde in serum was much lower than reported in the literature. Furthermore, concentrations of the formyl adduct were not higher in workers exposed to formaldehyde at about 1.5ppm than in controls. Follow-up in vitro experiments with gaseous formaldehyde at 1.4ppm detected the putative crosslink in plasma but not whole blood. This combination of results suggests that N(6) formylation occurs within cells with subsequent release of adducted HSA to the systemic circulation. Comparing across human

  10. Condensed tannin-resorcinol adducts in laminating adhesives

    Science.gov (United States)

    Richard W. Hemingway; Roland E. Kreibich

    1985-01-01

    A condensed tannin-resorcinol adduct made by co-reaction of an extract from southern pine bark with resorcinol at a 2 to 1 weight ratio was used to prepare a laminating resin in which the entire amount of resorcinol normally used was replaced by this adduct. The resin was formulated into a room temperature setting adhesive that meets the basic criteria of product...

  11. Adduction of untested derived stimulus relations depends on environmental complexity.

    Science.gov (United States)

    Rippy, Sterling M; Doughty, Adam H

    2017-10-01

    The present research assessed adduction involving derived stimulus relations as a function of environmental complexity. In Group CA, four college students were trained with arbitrary-matching-to-sample discriminations that could have established four, 3-member stimulus classes. In Group EA, four other students were trained with discriminations that could have established four, 5-member classes. Neither group received derived-relations testing; instead, adduction was assessed immediately after the baseline discriminations were learned. The adduction assessment required participants to derive the untested CA (Group CA) or EA (Group EA) equivalence relations and combine them with their already learned math skills. All participants in Group CA showed above 90% accuracy during the adduction assessment, whereas only one of four Group EA participants responded in that manner. These results extend adduction to untested equivalence relations and clarify the environmental conditions under which such adduction is less likely to occur (i.e., with larger relational networks). Copyright © 2017 Elsevier B.V. All rights reserved.

  12. A Synthetic Aptamer-Drug Adduct for Targeted Liver Cancer Therapy.

    Directory of Open Access Journals (Sweden)

    Thu Le Trinh

    Full Text Available AS1411 (previously known as AGRO100 is a 26 nucleotide guanine-rich DNA aptamer which forms a guanine quadruplex structure. AS1411 has shown promising utility as a treatment for cancers in Phase I and Phase II clinical trials without causing major side-effects. AS1411 inhibits tumor cell growth by binding to nucleolin which is aberrantly expressed on the cell membrane of many tumors. In this study, we utilized a simple technique to conjugate a widely-used chemotherapeutic agent, doxorubicin (Dox, to AS1411 to form a synthetic Drug-DNA Adduct (DDA, termed as AS1411-Dox. We demonstrate the utility of AS1411-Dox in the treatment of hepatocellular carcinoma (HCC by evaluating the targeted delivery of Dox to Huh7 cells in vitro and in a murine xenograft model of HCC.

  13. A Synthetic Aptamer-Drug Adduct for Targeted Liver Cancer Therapy.

    Science.gov (United States)

    Trinh, Thu Le; Zhu, Guizhi; Xiao, Xilin; Puszyk, William; Sefah, Kwame; Wu, Qunfeng; Tan, Weihong; Liu, Chen

    2015-01-01

    AS1411 (previously known as AGRO100) is a 26 nucleotide guanine-rich DNA aptamer which forms a guanine quadruplex structure. AS1411 has shown promising utility as a treatment for cancers in Phase I and Phase II clinical trials without causing major side-effects. AS1411 inhibits tumor cell growth by binding to nucleolin which is aberrantly expressed on the cell membrane of many tumors. In this study, we utilized a simple technique to conjugate a widely-used chemotherapeutic agent, doxorubicin (Dox), to AS1411 to form a synthetic Drug-DNA Adduct (DDA), termed as AS1411-Dox. We demonstrate the utility of AS1411-Dox in the treatment of hepatocellular carcinoma (HCC) by evaluating the targeted delivery of Dox to Huh7 cells in vitro and in a murine xenograft model of HCC.

  14. Electrophilic properties of patulin. N-acetylcysteine and glutathione adducts.

    Science.gov (United States)

    Fliege, R; Metzler, M

    2000-05-01

    In our studies on the electrophilic properties of the mycotoxin patulin (PAT), we have now investigated the nonenzymatic reaction of PAT with the thiol-containing tripeptide glutathione and its metabolic degradation product N-acetyl-L-cysteine (NAC). Adduct formation in aqueous phosphate buffer (pH 7.4) was studied by analytical HPLC/DAD, and most of the products were isolated by preparative HPLC. Structure elucidation was carried out mainly by means of high-resolution NMR experiments and comparison of the data with those previously obtained for PAT adducts formed with simple model nucleophiles such as 4-bromothiophenol and 2-mercaptoethanol [Fliege, R., and Metzler, M. (2000) Chem. Res. Toxicol. 13, 363-372]. The assigned structures were confirmed by UV spectroscopy, formation of daughter products from isolated adducts, and partly FAB-MS. The reaction pathways of PAT with NAC were qualitatively the same as those previously observed for the aliphatic thiol model compound 2-mercaptoethanol. Due to the chiral nature of NAC and the new chiral center generated during the reaction with PAT, two diastereomers of each adduct were formed and observed in HPLC analysis. The major products formed in the reaction of PAT with GSH were of the same structural type as obtained with NAC. In addition, three cyclic adducts were formed with GSH, arising from the nucleophilic activity of the alpha-amino groups of the glutamic acid and the cysteine residue. In contrast, free cysteine yielded a markedly different adduct pattern, possibly due to the preferred formation of mixed thiol/amine-type adducts involving the alpha-amino group.

  15. Structural basis for recognition of 5'-phosphotyrosine adducts by TDP2

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Ke; Kurahash, Kayo; Gao, Rui; Tsutakawa, Susan E.; Tainer, John A.; Pommier, Yves; Aihara, Hideki

    2012-12-19

    The DNA repair enzyme TDP2 resolves 5'-phosphotyrosyl-DNA adducts, and is responsible for resistance to anti-cancer drugs that target covalent topoisomerase-DNA complexes. TDP2 also participates in key signaling pathways during development and tumorigenesis, and cleaves a protein-RNA linkage during picornavirus replication. The crystal structure of zebrafish TDP2 bound to DNA reveals a deep and narrow basic groove that selectively accommodates the 5'-end of single-stranded DNA in a stretched conformation. The crystal structure of the full-length C. elegans TDP2 shows that this groove can also accommodate an acidic peptide stretch in vitro, with Glu and Asp sidechains occupying the DNA backbone phosphate binding sites. This extensive molecular mimicry suggests a potential mechanism for auto-regulation and how TDP2 may interact with phosphorylated proteins in signaling. Our study provides a framework to interrogate functions of TDP2 and develop inhibitors for chemotherapeutic and antiviral applications.

  16. Platinum-Based Chemotherapy Induces Methylation Changes in Blood DNA Associated with Overall Survival in Patients with Ovarian Cancer

    NARCIS (Netherlands)

    Flanagan, James M.; Wilson, Angela; Koo, Chail; Masrour, Nahal; Gallon, John; Loomis, Erick; Flower, Kirsty; Wilhelm-Benartzi, Charlotte; Hergovich, Alexander; Cunnea, Paula; Gabra, Hani; Braicu, Elena Ioana; Sehouli, Jalid; Darb-Esfahani, Silvia; Vanderstichele, Adriaan; Vergote, Ignace; Kreuzinger, Caroline; Castillo-Tong, Dan Cacsire; Wisman, G. Bea A.; Berns, Els Mjj; Siddiqui, Nadeem; Paul, James; Brown, Robert

    2017-01-01

    Purpose: DNA damage repair can lead to epigenetic changes. DNA mismatch repair proteins bind to platinum DNA adducts and at sites of DNA damage can recruit the DNA methylating enzyme DNMT1, resulting in aberrant methylation. We hypothesised that DNA damage repair during platinum-based chemotherapy

  17. Mechanism of Error-Free DNA Replication Past Lucidin-Derived DNA Damage by Human DNA Polymerase κ.

    Science.gov (United States)

    Yockey, Oliver P; Jha, Vikash; Ghodke, Pratibha P; Xu, Tianzuo; Xu, Wenyan; Ling, Hong; Pradeepkumar, P I; Zhao, Linlin

    2017-11-20

    DNA damage impinges on genetic information flow and has significant implications in human disease and aging. Lucidin-3-O-primeveroside (LuP) is an anthraquinone derivative present in madder root, which has been used as a coloring agent and food additive. LuP can be metabolically converted to genotoxic compound lucidin, which subsequently forms lucidin-specific N2-2'-deoxyguanosine (N2-dG) and N6-2'-deoxyadenosine (N6-dA) DNA adducts. Lucidin is mutagenic and carcinogenic in rodents but has low carcinogenic risks in humans. To understand the molecular mechanism of low carcinogenicity of lucidin in humans, we performed DNA replication assays using site-specifically modified oligodeoxynucleotides containing a structural analogue (LdG) of lucidin-N2-dG DNA adduct and determined the crystal structures of DNA polymerase (pol) κ in complex with LdG-bearing DNA and an incoming nucleotide. We examined four human pols (pol η, pol ι, pol κ, and Rev1) in their efficiency and accuracy during DNA replication with LdG; these pols are key players in translesion DNA synthesis. Our results demonstrate that pol κ efficiently and accurately replicates past the LdG adduct, whereas DNA replication by pol η, pol ι is compromised to different extents. Rev1 retains its ability to incorporate dCTP opposite the lesion albeit with decreased efficiency. Two ternary crystal structures of pol κ illustrate that the LdG adduct is accommodated by pol κ at the enzyme active site during insertion and postlesion-extension steps. The unique open active site of pol κ allows the adducted DNA to adopt a standard B-form for accurate DNA replication. Collectively, these biochemical and structural data provide mechanistic insights into the low carcinogenic risk of lucidin in humans.

  18. Possible rare congenital dysinnervation disorder: congenital ptosis associated with adduction.

    Science.gov (United States)

    Mendes, Sílvia; Beselga, Diana; Campos, Sónia; Neves, Arminda; Campos, Joana; Carvalho, Sílvia; Silva, Eduardo; Castro Sousa, João Paulo

    2015-01-01

    Ptosis is defined as an abnormally low position of the upper eyelid margin. It can be congenital or acquired, uni or bilateral, and isolated or associated with other ocular and nonocular defects. We report a case of a female child, aged 8 years, with congenital right ptosis increased on right adduction and with left ptosis on left adduction. There was no horizontal ocular movement limitation. Apparent underaction of the right inferior oblique muscle was also present. We believe that within the possible mechanisms it is more likely that it is a congenital innervation dysgenesis syndrome (CID)/congenital cranial dysinnervation disorder (CCDD).

  19. Protective role of CYP2E1 inhibitor diallyl disulfide (DADS) on alcohol-induced malondialdehyde-deoxyguanosine (M1dG) adduct formation.

    Science.gov (United States)

    Sapkota, Muna; Hottor, Tete K; DeVasure, Jane M; Wyatt, Todd A; McCaskill, Michael L

    2014-06-01

    Alcohol use disorders are often associated with lung disease. Alcohol exposure leads to the production of reactive oxygen species, lipid peroxidation, and formation of malondialdehyde (MDA) as well as to induce the expression of cytochrome p450 2E1 (CYP2E1). Likewise, cigarette smoking can lead to lung lipid peroxidation and formation of MDA. MDA can bind to DNA forming MDA-deoxyguanosine (M1dG) adducts, which have been implicated in alcohol-related cancers and cardiovascular disease. Because CYP2E1 regulates MDA production, and our previous studies have shown that alcohol and cigarette smoke can lead to MDA formation, we hypothesized that CYP2E1 would modulate M1dG adduct formation and single-strand DNA damage in alcohol- and cigarette smoke-exposed lung cells and tissue. Normal human bronchial epithelial cells (HBECs) were pretreated with 10 μM diallyl disulfide (DADS) for 1 hour and treated with 80 mM ethanol (EtOH) ± 5% cigarette smoke extract (CSE) for 3 hours for comet assay and 6 hours for CYP2E1, MDA, and M1dG adduct assays. C57BL/6 mice were administered 20% EtOH ad libitum in drinking water for 8 weeks and exposed to whole-body cigarette smoke for 5 weeks. Mice were also fed a CYP2E1 inhibitor, DADS, at 1 μM/g of feed in their daily diet for 7 weeks. Whole lung tissue homogenate was used for CYP2E1, MDA, and M1dG adduct assays. EtOH exposure significantly increased HBEC olive tail moment. DADS pretreatment of HBECs attenuated this EtOH effect. EtOH also induced MDA and M1dG adduct formation, which was also significantly reduced by DADS treatment. CSE ± EtOH did not enhance these effects. In lung tissue homogenate of 8-week alcohol-fed mice, MDA and M1dG adduct levels were significantly elevated in comparison with control mice and mice fed DADS while consuming alcohol. No increase in MDA and M1dG adduct formation was observed in 5-week cigarette smoke-exposed mice. These findings suggest that CYP2E1 plays a pivotal role in alcohol-induced M1dG adducts

  20. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442) is...

  1. Methyl-Cytosine-Driven Structural Changes Enhance Adduction Kinetics of an Exon 7 fragment of the p53 Gene

    Science.gov (United States)

    Malla, Spundana; Kadimisetty, Karteek; Fu, You-Jun; Choudhary, Dharamainder; Schenkman, John B.; Rusling, James F.

    2017-01-01

    Methylation of cytosine (C) at C-phosphate-guanine (CpG) sites enhances reactivity of DNA towards electrophiles. Mutations at CpG sites on the p53 tumor suppressor gene that can result from these adductions are in turn correlated with specific cancers. Here we describe the first restriction-enzyme-assisted LC-MS/MS sequencing study of the influence of methyl cytosines (MeC) on kinetics of p53 gene adduction by model metabolite benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), using methodology applicable to correlate gene damage sites for drug and pollutant metabolites with mutation sites. This method allows direct kinetic measurements by LC-MS/MS sequencing for oligonucleotides longer than 20 base pairs (bp). We used MeC and non-MeC (C) versions of a 32 bp exon 7 fragment of the p53 gene. Methylation of 19 cytosines increased the rate constant 3-fold for adduction on G at the major reactive CpG in codon 248 vs. the non-MeC fragment. Rate constants for non-CpG codons 244 and 243 were not influenced significantly by MeC. Conformational and hydrophobicity changes in the MeC-p53 exon 7 fragment revealed by CD spectra and molecular modeling increase the BPDE binding constant to G in codon 248 consistent with a pathway in which preceding reactant binding greatly facilitates the rate of covalent SN2 coupling.

  2. SOME SULFATO ADDUCTS AND DERIVATIVE: SYNTHESIS AND SPECTROSCOPIC STUDY

    Directory of Open Access Journals (Sweden)

    MOUHAMADOU BIRAME DIOP

    2014-11-01

    Full Text Available Three new adducts and derivative have been synthesized and studied by infrared and NMR spectroscopies. The suggested structures are discrete with a sulfate behaving as a monochelating, bichelating or monodentate ligand, the environments around the tin centre being octahedral or pentagonal bipyramidal. In all the studied compounds, proposed supramolecular architectures may be obtained when intermolecular hydrogen bonds are considered.

  3. [Sigma]-adducts of pyrimidines and pteridines : an NMR study

    NARCIS (Netherlands)

    Geerts, J.P.

    1978-01-01

    This thesis deals with the results obtained by an NMR investigation on anionic σ-adducts that are formed between a number of pyrimidines and potassium amide in liquid ammonia and the covalent addition complexes that are formed between a number of pteridines and liquid ammonia or

  4. Flanking bases influence the nature of DNA distortion by platinum 1,2-intrastrand (GG cross-links.

    Directory of Open Access Journals (Sweden)

    Debadeep Bhattacharyya

    Full Text Available The differences in efficacy and molecular mechanisms of platinum anti-cancer drugs cisplatin (CP and oxaliplatin (OX are thought to be partially due to the differences in the DNA conformations of the CP and OX adducts that form on adjacent guanines on DNA, which in turn influence the binding of damage-recognition proteins that control downstream effects of the adducts. Here we report a comprehensive comparison of the structural distortion of DNA caused by CP and OX adducts in the TGGT sequence context using nuclear magnetic resonance (NMR spectroscopy and molecular dynamics (MD simulations. When compared to our previous studies in other sequence contexts, these structural studies help us understand the effect of the sequence context on the conformation of Pt-GG DNA adducts. We find that both the sequence context and the type of Pt-GG DNA adduct (CP vs. OX play an important role in the conformation and the conformational dynamics of Pt-DNA adducts, possibly explaining their influence on the ability of many damage-recognition proteins to bind to Pt-DNA adducts.

  5. Flanking Bases Influence the Nature of DNA Distortion by Platinum 1,2-Intrastrand (GG) Cross-Links

    Science.gov (United States)

    Sharma, Shantanu; Pathmasiri, Wimal; King, Candice L.; Baskerville-Abraham, Irene; Boysen, Gunnar; Swenberg, James A.; Campbell, Sharon L.; Dokholyan, Nikolay V.; Chaney, Stephen G.

    2011-01-01

    The differences in efficacy and molecular mechanisms of platinum anti-cancer drugs cisplatin (CP) and oxaliplatin (OX) are thought to be partially due to the differences in the DNA conformations of the CP and OX adducts that form on adjacent guanines on DNA, which in turn influence the binding of damage-recognition proteins that control downstream effects of the adducts. Here we report a comprehensive comparison of the structural distortion of DNA caused by CP and OX adducts in the TGGT sequence context using nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations. When compared to our previous studies in other sequence contexts, these structural studies help us understand the effect of the sequence context on the conformation of Pt-GG DNA adducts. We find that both the sequence context and the type of Pt-GG DNA adduct (CP vs. OX) play an important role in the conformation and the conformational dynamics of Pt-DNA adducts, possibly explaining their influence on the ability of many damage-recognition proteins to bind to Pt-DNA adducts. PMID:21853154

  6. Mutagenic Spectra Arising from Replication Bypass of the 2,6-diamino-4-hydroxy-N5-methyl Formamidopyrimidine Adduct in Primate Cells

    Science.gov (United States)

    Earley, Lauriel F.; Minko, Irina G.; Christov, Plamen P.; Rizzo, Carmelo J.; Lloyd, R. Stephen

    2013-01-01

    DNA exposures to electrophilic methylating agents that are commonly used during chemotherapeutic treatments cause diverse chemical modifications of nucleobases, with reaction at N7-dG being the most abundant. Although this base modification frequently results in destabilization of the glycosyl bond and spontaneous depurination, the adduct can react with hydroxide ion to yield a stable, ring-opened MeFapy-dG and this lesion has been reported to persist in animal tissues. Results from prior in vitro replication bypass investigations of the MeFapy-dG adduct had revealed complex spectra of replication errors that differed depending on the identity of DNA polymerase and the local sequence context. In this study, a series of nine site-specifically modified MeFapy-dG-containing oligodeoxynucleotides were engineered into a shuttle vector and subjected to replication in primate cells. In all nine sequence contexts examined, MeFapy-dG was shown to be associated with a strong mutator phenotype, predominantly causing base substitutions, with G to T transversions being most common. Single and dinucleotide deletions were also found in a subset of the sequence contexts. Interestingly, single-nucleotide deletions occurred not only at the adducted site, but also one nucleotide downstream of the adduct. Standard models for primer-template misalignment could account for some, but not all mutations observed. These data demonstrate that in addition to mutagenesis predicted from replication of DNAs containing O6-Me-dG and O4-Me-dT, the MeFapy-dG adduct likely contributes to mutagenic events following chemotherapeutic treatments. PMID:23763662

  7. Conformational Preference and Fluorescence Response of a C-Linked C8-Biphenyl-Guanine Lesion in the NarI Mutational Hotspot: Evidence for Enhanced Syn Adduct Formation.

    Science.gov (United States)

    Berger, Florence D; Sturla, Shana J; Kung, Ryan W; Montina, Tony; Wetmore, Stacey D; Manderville, Richard A

    2018-01-16

    Aromatic chemical carcinogens can undergo enzymatic transformations to produce a range of electrophilic species that attach covalently to the C8-site of 2'-deoxyguanosine (dG) to afford C8-dG adducts. The most studied C8-dG adducts are formed from arylamines and contain a N-linkage separating the dG from the C8-aryl moiety. Other carcinogenic species result in direct aryl ring attachment to the dG moiety, resulting in C-linked adducts. The resulting C-linked adducts have reduced conformational flexibility compared to the corresponding N-linked C8-dG adducts, which can alter their orientation in the DNA duplex. Described herein are structural studies of a fluorescent C-linked 4-fluorobiphenyl-dG (FBP-dG) that has been incorporated into the reiterated G3-postion of the 12-mer NarI sequence and those containing other 5'-flanking nucleobases. FBP-dG displays a strong preference for adopting a syn conformation in the fully paired NarI duplex to produce an intercalated structure that exhibits stacking interactions between the C-linked biphenyl and the flanking bases. FBP-dG is also shown to significantly stabilize the slippage mutagenic intermediate (SMI) duplex containing the lesion and 5'-flanking base within a 2-base bulge. FBP-dG exhibits fluorescence sensitivity to SMI duplex formation that can readily distinguish it from the fully paired duplex. Molecular dynamics simulations and optical spectroscopy for the NarI oligonucleotides containing the C-linked FBP-dG predict increased rigidity of the biphenyl in the syn conformation. The greater propensity to generate the promutagenic syn conformation for the C-linked FBP-dG adduct compared to the N-linked 4-aminobiphenyl-dG adduct (ABP-dG) suggests greater mutagenicity for the C-linked analogue. These results highlight the effect of the adduct linkage type on the conformational properties of adducted DNA. The turn-on emission response of FBP-dG in the SMI duplex may be a powerful tool for monitoring SMI formation in the

  8. Gemcitabine causes minimal modulation of carboplatin-DNA monoadduct formation and repair in bladder cancer cells

    OpenAIRE

    Wang, Sisi; Zhang, Hongyong; Malfatti, Michael; de Vere White, Ralph; Lara, Primo N.; Turteltaub, Kenneth; Henderson, Paul; Pan, Chong-xian

    2010-01-01

    We are developing a method to identify cellular resistance to carboplatin by using accelerator mass spectrometry to measure carboplatin-DNA adducts formed from drug microdoses (~1/100th the therapeutic dose). Such an approach would be particularly useful if it is still valid in combination chemotherapy. We examined whether the addition of gemcitabine, another chemotherapeutic drug, could influence carboplatin-DNA adduct levels. There were no substantial differences in the levels of carboplati...

  9. EMG evaluation of hip adduction exercises for soccer players

    DEFF Research Database (Denmark)

    Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis

    2014-01-01

    traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...... for the adductor longus during eight hip adduction strengthening exercises and peak EMG was normalised (nEMG) using an isometric maximal voluntary contraction (MVC) as reference. Furthermore, muscle activation of the gluteus medius, rectus abdominis and the external abdominal obliques was analysed during...... the exercises. RESULTS: There were large differences in peak nEMG of the adductor longus between the exercises, with values ranging from 14% to 108% nEMG (pEMG results for the gluteals...

  10. Biocidal properties of metal oxide nanoparticles and their halogen adducts

    Science.gov (United States)

    Haggstrom, Johanna A.; Klabunde, Kenneth J.; Marchin, George L.

    2010-03-01

    Nanosized metal oxide halogen adducts possess high surface reactivities due to their unique surface morphologies. These adducts have been used as reactive materials against vegetative cells, such as Escherichia coli as well as bacterial endospores, including Bacillus subtilis and Bacillus anthracis (Δ Sterne strain). Here we report high biocidal activities against gram-positive bacteria, gram-negative bacteria, and endospores. The procedure consists of a membrane method. Transmission electron micrographs are used to compare nanoparticle-treated and untreated cells and spores. It is proposed that the abrasive character of the particles, the oxidative power of the halogens/interhalogens, and the electrostatic attraction between the metal oxides and the biological material are responsible for high biocidal activities. While some activity was demonstrated, bacterial endospores were more resistant to nanoparticle treatment than the vegetative bacteria.

  11. NEW HALO- AND ORGANOTIN (IV PHENYLARSENIATO ADDUCTS AND DERIVATIVES

    Directory of Open Access Journals (Sweden)

    BOCAR TRAORE

    2013-12-01

    Full Text Available Four new phenylarseniato adducts and organotin derivatives have been synthesized and studied by infrared. The suggested structures are polymeric, (SnX4; X = Cl, Br and SnPh3Cl while being discrete for SnPh2Cl(PhAsO3H2isoBu2NH2. When OH- - - Cl, NH - - - O or NH- - -Cl hydrogen bonds are involved, supramolecular architectures are obtained.

  12. SOME NEW SULFONATO ADDUCT: SYNTHESIS AND SPECTROSCOPIC STUDIES

    Directory of Open Access Journals (Sweden)

    MOUHAMADOU BIRAME DIOP

    2015-02-01

    Full Text Available Three new adducts have been synthesized and studied by infrared and NMR spectroscopies. The suggested structures are discrete with a pyridine -3- sulfonate acting as a tri O-chelating and N-donor or as a non σ coordinating ligand, a 4-aminobenzenesulfonate behaving as a monodentate O-donor, the environments around the tin centre being tetrahedral, octahedral or seven coordinated. In all the studied compounds, supramolecular architectures are obtained when hydrogen bonds are considered.

  13. Ion Pairs or Neutral Molecule Adducts? Cooperativity in Hydrogen Bonding

    Science.gov (United States)

    DeKock, Roger L.; Schipper, Laura A.; Dykhouse, Stephanie C.; Heeringa, Lee P.; Brandsen, Benjamin M.

    2009-01-01

    We performed theoretical studies on the systems NH[subscript 3] times HF times mH[subscript 2]O, NH[subscript 3] times HCl times mH[subscript 2]O, with m = 0, 1, 2, and 6. The molecules with m = 0 form hydrogen-bonded adducts with little tendency to form an ion-pair structure. The molecule NH[subscript 3] times HCl times H[subscript 2]O cannot be…

  14. NEW HYDROGENOXALATO ADDUCTS AND MALONATO COMPLEX: SYNTHESIS AND SPECTROSCOPIC STUDIES

    Directory of Open Access Journals (Sweden)

    MOUHAMADOU BIRAME DIOP

    2014-08-01

    Full Text Available Two new hydrogenoxalato and one malonato adduct and complex have been synthesized and studied by infrared and NMR spectroscopies. The suggested structures are discrete, the hydrogenoxalate behaving as a monodentate ligand or only involved in hydrogen bonding, the environment around the tin (IV centre being tetrahedral or trigonal bipyramidal. The malonate anion is a monodentate ligand. In all the suggested structures, when extra hydrogen bonds are considered, supramolecular architectures are obtained.

  15. PHOSPHATO AND PHOSPHONATO ADDUCTS: SYNTHESIS AND SPECTROSCOPIC STUDY

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2014-05-01

    Full Text Available Two new adducts have been synthesized and studied by infrared and NMR spectroscopy. The suggested structures are discrete or of infinite chain type with a phosphate behaving as a bidentate ligand, a phosphonate acting as a monodentate ligand, the environments around the tin centre being tetrahedral or trigonal bipyramidal. In all the studied compounds, supramolecular architectures are obtained when hydrogen bonds are considered.

  16. Detection of Dichlorvos Adducts in a Hepatocyte Cell Line

    Science.gov (United States)

    2014-06-30

    treatment affects glucose homeostasis in multiple ways.12,42−45 Here we found DDVP adduction to proteins crucial to the glycolytic/ gluconeogenesis ...differentiation Development_TGF-beta-dependent induction of EMT via RhoA, PI3K and ILK. 2 energy regulation Glycolysis and gluconeogenesis (short map) 3...energy regulation Glycolysis and gluconeogenesis p. 2 2 energy regulation Pentose phosphate pathway 2 energy regulation Transcription_Role of Akt in

  17. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin, E-mail: binli@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Eyer, Peter, E-mail: peter.eyer@lrz.uni-muenchen.de [Walther-Straub-Institut Für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München (Germany); Eddleston, Michael, E-mail: M.Eddleston@ed.ac.uk [Clinical Pharmacology Unit, University of Edinburgh, Edinburgh (United Kingdom); Jiang, Wei, E-mail: wjiang@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Schopfer, Lawrence M., E-mail: lmschopf@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Lockridge, Oksana, E-mail: olockrid@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States)

    2013-06-15

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates.

  18. Dispersant additives derived from lactone modified amido-amine adducts

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, A.; Lundberg, R.D.

    1990-10-16

    This patent describes a lactone modified dispersant additive. It comprises one adduct of a polyolefin of 300 to 10,000 number average molecular weight substituted with at least 0.8 (e.g., from about 1 to 4) dicarboxylic acid producing moieties (preferably acid or anhydride moieties) per polyolefin molecule, an amido-amine or thioamido-amine characterized by being a reaction product of at least a polyamine and an alpha, beta-unsaturated compound.

  19. Diagnosis and dosimetry of exposure to sulfur mustard: Development of a standard operating procedure for mass spectrometric analysis of haemoglobin adducts - Exploratory research on albumin and keratin adducts

    NARCIS (Netherlands)

    Noort, D.; Fidder, A.; Hulst, A.G.; Jong, L.P.A. de; Benschop, H.P.

    2000-01-01

    Experiments were carried out to develop a standard operating procedure for analysis of sulfur mustard adducts to the N-terminal valine in haemoglobin and to explore adduct formation with albumin and keratin. In the first approach, gas chromatography-negative chemical ionization/mass spectrometry

  20. Hip adduction and abduction strength profiles in elite, sub-elite and amateur Australian footballers.

    Science.gov (United States)

    Prendergast, Ned; Hopper, Diana; Finucane, Mark; Grisbrook, Tiffany L

    2016-09-01

    It has been reported that obtaining an adduction-to-abduction strength ratio of 90-100%, and an adduction strength equal to that of the uninjured side, are suitable clinical milestones for return to sport following groin injury. Little is known about hip adduction and abduction strength profiles in Australian footballers. This study aimed to compare isometric hip adduction and abduction strength profiles between preferred and non-preferred kicking legs in elite, sub-elite and amateur Australian footballers. Cross sectional study 36 elite, 19 sub-elite and 18 amateur Australian footballers, with a mean age of 24, 19 and 23 years respectively, were included. Maximal hip isometric adduction and abduction strength were measured using a hand held dynamometer with external belt fixation. There were no significant differences in isometric hip adduction (p=0.262) or abduction (p=0.934) strength, or the adduction-to-abduction ratio (p=0.163), between preferred and non-preferred kicking legs, regardless of playing level. Elite players had significantly greater isometric hip adduction and abduction strength than both sub-elite (mean difference; adduction=46.01N, pamateur players (mean difference; adduction=78.72N, p<0.001, abduction=59.11N, p<0.001). There was no significant difference in the adduction-to-abduction ratio between the playing levels (p=0.165). No significant differences were found between preferred and non-preferred kicking legs across the playing levels for isometric hip adduction, abduction or the adduction-to-abduction ratio. This may have implications for developing groin injury prediction and return to sport criteria in Australian footballers. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Acetaminophen Adducts Detected in Serum of Pediatric Patients With Acute Liver Failure.

    Science.gov (United States)

    Alonso, Estella M; James, Laura P; Zhang, Song; Squires, Robert H

    2015-07-01

    Previous studies in patients with acute liver failure identified acetaminophen (APAP) protein adducts in the serum of 12% and 19% of children and adults, respectively, with acute liver failure of indeterminate etiology. This article details the testing of APAP adducts in a subset (n = 393) of patients with varied diagnoses in the Pediatric Acute Liver Failure Study Group (PALFSG). Serum samples were available from 393 participants included in the PALFSG registry. Adduct measurement was performed using validated methods. Participants were grouped by diagnostic category as known APAP overdose, known other diagnosis, and indeterminate etiology. Demographic and clinical characteristics and participant outcomes were compared by adduct status (positive or negative) within each group. APAP adduct testing was positive in 86% of participants with known APAP overdose, 6% with other known diagnoses, and 11% with an indeterminate cause of liver failure. Adduct-positive participants were noted to have marked elevation of serum alanine aminotransferase and aspartate aminotransferase coupled with total serum bilirubin that was significantly lower than adduct-negative patients. In the indeterminate group, adduct-positive patients had different outcomes than adduct-negative patients (P = 0.03); spontaneous survival was 16 of 21 (76%) in adduct-positive patients versus 75 of 169 (44%) in adduct-negative patients. Prognosis did not vary by adduct status in patients with known diagnoses. Furthermore, study is needed to understand the relation of APAP exposure, as determined by the presence of APAP adducts, to the clinical phenotype and outcomes of children with acute liver failure.

  2. DNA damage by reactive species: Mechanisms, mutation and repair

    Indian Academy of Sciences (India)

    2012-06-25

    Jun 25, 2012 ... guanine-guanine DNA adducts in human leukocytes by high-performance liquid chromatography coupled to induc- tively coupled plasma mass spectrometry. Chem. Res. Toxicol. 23 1313–132. Hedglin M and O'Brien PJ 2010 Nonspecifically bound proteins spin while diffusing along DNA. ACS Chem. Biol.

  3. Comparison of the toxicities of patulin and patulin adducts formed with cysteine.

    Science.gov (United States)

    Lindroth, S; von Wright, A

    1978-01-01

    The toxicities of patulin and of the patulin adducts formed with cysteine were compared using the mutation-sensitive strain Escherichia coli W3110 thy polA1 and its polA1+ revertant. The acute toxicities of patulin and of the adduct mixture were also compared using NMRI mice. The adduct mixture was shown by thin-layer chromatography to consist of one ninhydrin-positive, one ninhydrin- and MBTH (3-methyl-2-benzothiazolinone hydrazone)-positive, three MBTH-positive, and two ninhydrin- and MBTH-negative components. The results showed that patulin was over 100 times more toxic to E. coli than the adduct complex. Neither patulin nor the adduct mixture was found to induce the repair effect in E. coli. In the mouse feeding tests, the oral 50% lethal dose for patulin was 29 mg/kg, while that of the adduct mixture was greater than 2,370 mg/kg. PMID:354524

  4. Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Soon-Hyuck Lee

    Full Text Available It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec and total work (180°/sec of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037 and hamstring (r = 0.426, P = 0.045 muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041. Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032. The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle.

  5. Synthesis and Characterization of the Adducts of Bis(O-ethyldithiocarbonatocopper(II with Substituted Pyridines

    Directory of Open Access Journals (Sweden)

    Gurpreet Kour

    2013-01-01

    Full Text Available Monomeric five coordinated adducts of bis(O-ethyldithiocarbonatocopper(II of general formula [Cu(C2H5OCS22(L], [L = 2-, 3-, 4-methylpyridines and 2-, 3-, 4-ethylpyridines] have been synthesized and characterized by elemental analysis, i.r. and electronic spectroscopy, magnetic and conductivity measurements. Analytical results show that the adducts have 1 : 1 stoichiometry. The adducts were found to be paramagnetic and their magnetic moments at room temperature lie within the 1.81–1.94 B.M. range and this indicates the presence of one unpaired electron. All the adducts have distorted square pyramidal geometry.

  6. Lifetimes and stabilities of familiar explosives molecular adduct complexes during ion mobility measurements

    Science.gov (United States)

    McKenzie, Alan; DeBord, John Daniel; Ridgeway, Mark; Park, Melvin; Eiceman, Gary; Fernandez-Lima, Francisco

    2015-01-01

    Trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) was utilized for the separation and identification of familiar explosives in complex mixtures. For the first time, molecular adduct complex lifetimes, relative stability, binding energies and candidate structures are reported for familiar explosives. Experimental and theoretical results showed that the adduct size and reactivity, complex binding energy and the explosive structure tailors the stability of the molecular adduct complex. TIMS flexibility to adapt the mobility separation as a function of the molecular adduct complex stability (i.e., short or long IMS experiments / low or high IMS resolution) permits targeted measurements of explosives in complex mixtures with higher confidence levels. PMID:26153567

  7. Including the Copenhagen Adduction Exercise in the FIFA 11+ Provides Missing Eccentric Hip Adduction Strength Effect in Male Soccer Players: A Randomized Controlled Trial.

    Science.gov (United States)

    Harøy, Joar; Thorborg, Kristian; Serner, Andreas; Bjørkheim, André; Rolstad, Linn E; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar

    2017-11-01

    The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength. To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen adduction exercise. Randomized controlled trial; Level of evidence, 1. We recruited 45 eligible players from 2 U19 elite male soccer teams. Players were randomized into 2 groups; 1 group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+ but replaced the Nordic hamstring exercise with the Copenhagen adduction exercise. Both groups performed the intervention 3 times weekly for 8 weeks. Players completed eccentric strength and sprint testing before and after the intervention. Per-protocol analyses were performed, and 12 players were excluded due to low compliance (FIFA 11+ program (-0.02 N·m/kg [-0.7%]; P = .69). Including the Copenhagen adduction exercise in the FIFA 11+ program increases eccentric hip adduction strength, while the standard FIFA 11+ program does not. Registration: Registration: ISRCTN13731446 (International Standard Randomised Controlled Trial Number registry).

  8. Isolation and characterization of pyrimidine-psoralen photoadducts from DNA

    Energy Technology Data Exchange (ETDEWEB)

    Straub, K.; Kanne, D.; Hearst, J.E.; Rapoport, H.

    1981-05-06

    We have examined the photoadducts of 4'-hydroxymethyl-4,5',8-trimethylpsoralen (HMT) and native DNA. Five nucleoside-HMT monoaddition products have been isolated and characterized, corresponding to three deoxythymidine-HMT and two deoxyuridine (derived from deoxycytidine)-HMT adducts. Structural assignments are based on high resolution mass spectrometry and /sup 1/H NMR studies, including homonuclear spin decoupling and nuclear Overhauser effect (NOE) experiments. The results of this study indicate that (1) a limited number of nucleoside-psoralen adducts are formed with native, double-stranded DNA, and (2) the sterochemistry of the adducts is apparently determined by the geometry of the noncovalent intercalative complex formed by HMT and DNA prior to irradiation. 8 figures, 8 tables.

  9. Unraveling the Photoswitching Mechanism in Donor-Acceptor Stenhouse Adducts.

    Science.gov (United States)

    Lerch, Michael M; Wezenberg, Sander J; Szymanski, Wiktor; Feringa, Ben L

    2016-05-25

    Molecular photoswitches have opened up a myriad of opportunities in applications ranging from responsive materials and control of biological function to molecular logics. Here, we show that the photoswitching mechanism of donor-acceptor Stenhouse adducts (DASA), a recently reported class of photoswitches, proceeds by photoinduced Z-E isomerization, followed by a thermal, conrotatory 4π-electrocyclization. The photogenerated intermediate is manifested by a bathochromically shifted band in the visible absorption spectrum of the DASA. The identification of the role of this intermediate reveals a key step in the photoswitching mechanism that is essential to the rational design of switching properties via structural modification.

  10. [Metatarsus Varus among Forefoot Adduction Deformities in Children.].

    Science.gov (United States)

    Charvát, J

    1996-01-01

    The author identifies main etiologic factors causing intoeing in children. The levels hip joint and proximal femur-tibial torsion and foot deformities are followed. Among foot deformities metatarsus varus in pointed out and described, as the literature is not yet uniform about strict criteria. The clinical appearance is shown and X-ray signs-subluxation of os naviculare laterally on talus and changes of shape of os cuneiforme primum are mentioned. Discussed is conservative therapy-excersises and plaster casts. Key words: metatarsus varus, pes equinovarus, forefoot adduction, X-ray, torsional deformities.

  11. Fullerene–Carbene Lewis Acid–Base Adducts

    KAUST Repository

    Li, Huaping

    2011-08-17

    The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths similar to those of n-doped fullerenes were observed for the product, consistent with a net transfer of electron density to the C60 core. Corroborating information was obtained using UV photoelectron spectroscopy, which revealed that the adduct has an ionization potential ∼1.5 eV lower than that of C60. Density functional theory calculations showed that the C-C bond is polarized, with a total charge of +0.84e located on the NHC framework and -0.84e delocalized on the C 60 cage. The combination of reactivity, characterization, and theoretical studies demonstrates that fullerenes can behave as Lewis acids that react with C-based Lewis bases and that the overall process describes n-doping via C-C bond formation. © 2011 American Chemical Society.

  12. A Mathematical Model for DNA Damage and Repair

    Directory of Open Access Journals (Sweden)

    Philip S. Crooke

    2010-01-01

    Full Text Available In cells, DNA repair has to keep up with DNA damage to maintain the integrity of the genome and prevent mutagenesis and carcinogenesis. While the importance of both DNA damage and repair is clear, the impact of imbalances between both processes has not been studied. In this paper, we created a combined mathematical model for the formation of DNA adducts from oxidative estrogen metabolism followed by base excision repair (BER of these adducts. The model encompasses a set of differential equations representing the sequence of enzymatic reactions in both damage and repair pathways. By combining both pathways, we can simulate the overall process by starting from a given time-dependent concentration of 17β-estradiol (E2 and 2′-deoxyguanosine, determine the extent of adduct formation and the correction by BER required to preserve the integrity of DNA. The model allows us to examine the effect of phenotypic and genotypic factors such as different concentrations of estrogen and variant enzyme haplotypes on the formation and repair of DNA adducts.

  13. Structural and dynamic characterization of polymerase κ's minor groove lesion processing reveals how adduct topology impacts fidelity.

    Science.gov (United States)

    Lior-Hoffmann, Lee; Ding, Shuang; Geacintov, Nicholas E; Zhang, Yingkai; Broyde, Suse

    2014-09-09

    DNA lesion bypass polymerases process different lesions with varying fidelities, but the structural, dynamic, and mechanistic origins of this phenomenon remain poorly understood. Human DNA polymerase κ (Polκ), a member of the Y family of lesion bypass polymerases, is specialized to bypass bulky DNA minor groove lesions in a predominantly error-free manner, by housing them in its unique gap. We have investigated the role of the unique Polκ gap and N-clasp structural features in the fidelity of minor groove lesion processing with extensive molecular modeling and molecular dynamics simulations to pinpoint their functioning in lesion bypass. Here we consider the N(2)-dG covalent adduct derived from the carcinogenic aromatic amine, 2-acetylaminofluorene (dG-N(2)-AAF), that is produced via the combustion of kerosene and diesel fuel. Our simulations reveal how the spacious gap directionally accommodates the lesion aromatic ring system as it transits through the stages of incorporation of the predominant correct partner dCTP opposite the damaged guanine, with preservation of local active site organization for nucleotidyl transfer. Furthermore, flexibility in Polκ's N-clasp facilitates the significant misincorporation of dTTP opposite dG-N(2)-AAF via wobble pairing. Notably, we show that N-clasp flexibility depends on lesion topology, being markedly reduced in the case of the benzo[a]pyrene-derived major adduct to N(2)-dG, whose bypass by Polκ is nearly error-free. Thus, our studies reveal how Polκ's unique structural and dynamic properties can regulate its bypass fidelity of polycyclic aromatic lesions and how the fidelity is impacted by lesion structures.

  14. On adduct formation and reactivity in the OCS plus OH reaction

    DEFF Research Database (Denmark)

    Schmidt, Johan Albrecht; Kyte, Mildrid; Østerstrøm, Freja From

    2017-01-01

    The OCS + OH reaction occurs either via adduct formation or direct S-abstraction. We investigate OH-oxidation of OCS using quantum chemical methods and find that the OC(OH)S adduct reacts rapidly with O2forming SOOH + CO2. SOOH rapidly dissociates under atmospheric conditions regenerating OH. We ...

  15. Condensed tannin-resorcinol adducts and their use in wood-laminating adhesives: An exploratory study

    Science.gov (United States)

    Richard W. Hemingway; R.E. Kreibich

    1984-01-01

    The reaction of a tannin extract (containing about 30% carbohydrate) from loblolly pine (Pinus taeda L.) bark (two parts) and resorcinol (one part) at 120°C for 24 h with acetic acid catalyst gave a product containing predominantly oligomeric procyanidin-4-resorcinol adducts (39%), unreacted resorcinol (22%), carbohydrate (20%). the resorcinol adduct...

  16. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene oxide...

  17. Effect of external electric field on Cyclodextrin-Alcohol adducts: A ...

    Indian Academy of Sciences (India)

    bility of the cyclodextrin-alcohol adducts was measured in terms of DFT based reactivity descriptor, global hardness, electrophilicity, and energy of the HOMO. Stability of adducts was observed to be sensitive towards the strength as well as direction of the applied external electric field. In addition, reactivity pattern follows the.

  18. 40 CFR 721.1850 - Toluene sulfonamide bis-phe-nol A epoxy adduct.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Toluene sulfonamide bis-phe-nol A... Specific Chemical Substances § 721.1850 Toluene sulfonamide bis-phe-nol A epoxy adduct. (a) Chemical... as toluene sulfonamide bisphenol A epoxy adduct (PMN P-90-113) is subject to reporting under this...

  19. Effect of chelate-ring over the stabilization of copper-dioxygen adducts

    Indian Academy of Sciences (India)

    Administrator

    Effect of chelate-ring over the stabilization of copper-dioxygen adducts. RAJEEV GUPTA and RABINDRANATH MUKHERJEE. Department of Chemistry, Indian Institute of Technology,. Kanpur 208 016, India. Copper-dioxygen adducts are very important in biological systems as well as in synthetic oxidation chemistry.

  20. Immunochemical detection of sulfur mustard adducts with keratins in the stratum corneum of human skin

    NARCIS (Netherlands)

    Schans, G.P. van der; Noort, D.; Mars-Groenendijk, R.H.; Fidder, A.; Chau, L.F.; Jong, L.P.A. de; Benschop, H.P.

    2002-01-01

    As part of a program to develop methods for diagnosis of exposure to chemical warfare agents, we developed immunochemical methods for detection of adducts of sulfur mustard to keratin in human skin. Three partial sequences of keratins containing glutamine or asparagine adducted with a

  1. A Novel 14C-Postlabeling Assay Using Accelerator Mass Spectrometry For the Detection of O6-Methyldeoxyguanosine Adducts

    Energy Technology Data Exchange (ETDEWEB)

    Thompkins, E M; Farmer, P B; Lamb, J H; Jukes, R; Dingley, K; Ubick, E A; Turteltaub, K W; Martin, E A; Brown, K

    2005-11-17

    Accelerator mass spectrometry (AMS) is currently one of the most sensitive methods available for the trace detection of DNA adducts and is particularly valuable for measuring adducts in humans or animal models. However, the standard approach requires administration of a radiolabeled compound. As an alternative, we have developed a preliminary {sup 14}C-postlabeling assay for detection of the highly mutagenic O{sup 6}-MedG, by AMS. Procedures were developed for derivatizing O{sup 6}-MedG using unlabeled acetic anhydride. Using conventional LC-MS analysis, the limit of detection for the major product, triacetylated O{sup 6}-MedG, was 10 fmoles. On reaction with {sup 14}C-acetic anhydride, using a specially designed enclosed system, the predominant product was {sup 14}C-di-acetyl O{sup 6}-MedG. This change in reaction profile was due to a modification of the reaction procedure, introduced as a necessary safety precaution. The limit of detection for {sup 14}C-diacetyl O{sup 6}-MedG by AMS was determined as 79 attomoles, {approx}18,000 fold lower than that achievable by LSC. Although the assay has so far only been carried out with labeled standards, the degree of sensitivity obtained illustrates the potential of this assay for measuring O{sup 6}-MedG levels in humans.

  2. Quantitation of 4,4′-methylene diphenyl diisocyanate human serum albumin adducts

    Directory of Open Access Journals (Sweden)

    Leah G. Luna

    2014-01-01

    Full Text Available 4,4′-Methylene diphenyl diisocyanate (herein 4,4′-MDI is used in the production of polyurethane foams, elastomers, coatings, adhesives and the like for a wide range of commercial products. Occupational exposure to MDI levels above current airborne exposure limits can elicit immune mediated hypersensitivity reactions such as occupational asthma in sensitive individuals. To accurately determine exposure, there has been increasing interest in developing analytical methods to measure internal biomarkers of exposure to MDI. Previous investigators have reported methodologies for measuring MDI diamine metabolites and MDI-Lysine (4,4′-MDI-Lys adducts. The purpose of this study was to develop and validate an ultra performance liquid chromatography isotope dilution tandem mass spectrometry (UPLC-ID/MS/MS quantitation method via a signature peptide approach to enable biomonitoring of 4,4′-MDI adducted to human serum albumin (HSA in plasma. A murine, anti-4,4′-MDI monoclonal IgM antibody was bound to magnetic beads and utilized for enrichment of the MDI adducted HSA. Following enrichment, trypsin digestion was performed to generate the expected 414 site (primary site of adduction 4,4′-MDI-adducted HSA signature peptide that was quantified by UPLC-ID/MS/MS. An Agilent 6530 UPLC/quadrupole time of flight MS (QTOF system was utilized for intact adducted protein analysis and an Agilent 6490 UPLC/MS/MS system operated in multiple reaction monitoring (MRM mode was utilized for quantification of the adducted signature peptide biomarker both for in chemico and worker serum samples. Worker serum samples were initially screened utilizing the previously developed 4,4′-MDI-Lys amino acid method and results showed that 12 samples were identified as quantifiable for 4,4′-MDI-Lys adducts. The signature peptide adduct approach was applied to the 12 worker samples identified as quantifiable for 4,4′-MDI-Lys adducts. Results indicated no positive results

  3. Quantitation of 4,4'-methylene diphenyl diisocyanate human serum albumin adducts.

    Science.gov (United States)

    Luna, Leah G; Green, Brett J; Zhang, Fagen; Arnold, Scott M; Siegel, Paul D; Bartels, Michael J

    4,4'-Methylene diphenyl diisocyanate (herein 4,4'-MDI) is used in the production of polyurethane foams, elastomers, coatings, adhesives and the like for a wide range of commercial products. Occupational exposure to MDI levels above current airborne exposure limits can elicit immune mediated hypersensitivity reactions such as occupational asthma in sensitive individuals. To accurately determine exposure, there has been increasing interest in developing analytical methods to measure internal biomarkers of exposure to MDI. Previous investigators have reported methodologies for measuring MDI diamine metabolites and MDI-Lysine (4,4'-MDI-Lys) adducts. The purpose of this study was to develop and validate an ultra performance liquid chromatography isotope dilution tandem mass spectrometry (UPLC-ID/MS/MS) quantitation method via a signature peptide approach to enable biomonitoring of 4,4'-MDI adducted to human serum albumin (HSA) in plasma. A murine, anti-4,4'-MDI monoclonal IgM antibody was bound to magnetic beads and utilized for enrichment of the MDI adducted HSA. Following enrichment, trypsin digestion was performed to generate the expected 414 site (primary site of adduction) 4,4'-MDI-adducted HSA signature peptide that was quantified by UPLC-ID/MS/MS. An Agilent 6530 UPLC/quadrupole time of flight MS (QTOF) system was utilized for intact adducted protein analysis and an Agilent 6490 UPLC/MS/MS system operated in multiple reaction monitoring (MRM) mode was utilized for quantification of the adducted signature peptide biomarker both for in chemico and worker serum samples. Worker serum samples were initially screened utilizing the previously developed 4,4'-MDI-Lys amino acid method and results showed that 12 samples were identified as quantifiable for 4,4'-MDI-Lys adducts. The signature peptide adduct approach was applied to the 12 worker samples identified as quantifiable for 4,4'-MDI-Lys adducts. Results indicated no positive results were obtained above the

  4. Cresyl saligenin phosphate makes multiple adducts on free histidine, but does not form an adduct on histidine 438 of human butyrylcholinesterase.

    Science.gov (United States)

    Liyasova, Mariya S; Schopfer, Lawrence M; Lockridge, Oksana

    2013-03-25

    Cresyl saligenin phosphate (CBDP) is a suspected causative agent of "aerotoxic syndrome", affecting pilots, crew members and passengers. CBDP is produced in vivo from ortho-containing isomers of tricresyl phosphate (TCP), a component of jet engine lubricants and hydraulic fluids. CBDP irreversibly inhibits butyrylcholinesterase (BChE) in human plasma by forming adducts on the active site serine (Ser-198). Inhibited BChE undergoes aging to release saligenin and o-cresol. The active site histidine (His-438) was hypothesized to abstract o-hydroxybenzyl moiety from the initial adduct on Ser-198. Our goal was to test this hypothesis. Mass spectral analysis of CBDP-inhibited BChE digested with Glu-C showed an o-hydroxybenzyl adduct (+106 amu) on lysine 499, a residue far from the active site, but not on His-438. Nevertheless, the nitrogen of the imidazole ring of free L-histidine formed a variety of adducts upon reaction with CBDP, including the o-hydroxybenzyl adduct, suggesting that histidine-CBDP adducts may form on other proteins. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. DNA damage induced in mouse tissues by organic wood preserving waste extracts as assayed by {sup 32}P-postlabeling

    Energy Technology Data Exchange (ETDEWEB)

    Randerath, E. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States); Zhou, G.D. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States); Donnelly, K.C. [Department of Veterinary Anatomy and Public Health, Texas A and M University, College Station, TX (United States); Safe, S.H. [Department of Veterinary Physiology/Pharmacology, Texas A and M University, College Station, TX (United States); Randerath, K. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States)

    1996-09-01

    In the present study, a mouse bioassay was used in combination with {sup 32}P-postlabeling to determine DNA adduct formation induced by hexane/acetone extracts of two samples from a WPW site. Female ICR mice were treated dermally with extract corresponding to 3 mg residue or vehicle control once per day for 2 days and killed 24 h later. Skin, lung, liver, kidney, and heart DNA preparations were assayed by nuclease P1-enhanced postlabeling. Adduct profiles were tissue-specific and displayed a multitude of non-polar DNA adducts with levels amounting to one adduct in 1.6 x 10{sup 6} DNA nucleotides in skin (both extracts) and one adduct in 3.2 x 10{sup 7} or 1.2 x 10{sup 7} DNA nucleotides in liver (extract 1 or extract 2). Based on their chromatographic properties, these adducts appeared largely derived from polycyclic aromatic hydrocarbons (PAHs) present in the extracts. One of the major adducts was identified as the {sup 32}P-labeled derivative of the reaction product of 7{beta}, 8{alpha}-dihydroxy-9{alpha}, 10{alpha}-epoxy-7, 8, 9, 10-tetrahydrobenzo[a]pyrene (BPDE I) with N{sup 2} of deoxyguanosine. Total non-polar DNA adduct levels were highest in skin and lung, amounting to 17.4 and 24.0% of the skin values for extracts 1 and 2, respectively, in lung while the corresponding levels in liver were 5.0 and 12.6%. These results were in accord with the carcinogenic potencies of PAHs in these organs. Extract 2 induced higher adduct levels in internal organs, although its PAH concentrations were lower than those of extract 1, i.e. lung, liver, kidney, and heart had 1.4, 2.5, 1.9, and 1.7 times higher total adduct levels and 1.6, 3.3, 1.6, and 1.9 times higher benzo[a]pyrene adduct levels. With the exception of total adducts in lung, the differences between the two extracts were all significant, suggestive of compound interactions. (orig.) (orig.). With 5 figs., 6 tabs.

  6. Molecular dosimetry of DNA damage induced by polycyclic aromatic hydrocarbons; relevance for exposure monitoring and risk assessment.

    Science.gov (United States)

    Baan, R A; Steenwinkel, M J; van den Berg, P T; Roggeband, R; van Delft, J H

    1994-12-01

    Polycyclic aromatic hydrocarbons (PAH) form a large group of organic chemicals that are widely distributed in our environment as pollutants of air, water and soil. Several PAH are carcinogenic in rodents, while exposure to these compounds has been associated with various types of human cancer. Upon entering the body, PAH may be converted into reactive electrophilic species, which can give rise to the formation of DNA adducts. DNA adduct formation is considered to be the initial event in chemical carcinogenesis. In this paper, two methods are illustrated that are widely used to determine PAH-DNA adduct formation, namely 32P-postlabelling, and immunochemical analysis with specific antibodies. The applications of the 32P-postlabelling assay comprise the following: A study of interspecies differences in PAH bioactivation in vitro, with microsomal preparations isolated from liver tissue of various rodent species and of human origin; the results indicate that there are considerable qualitative differences between the adduct patterns obtained, which is relevant with respect to extrapolation from animal to man. The analysis of DNA adduct formation in fish retrieved from marine environments polluted to various extents with PAH; results of these studies show a correlation between liver-DNA adduct levels in these fish and the degree of PAH contamination in the aquatic environment. Biomonitoring of PAH exposure through analysis of adducts in blood cells obtained from heavy and light smokers; the data show a fair correlation between PAH-DNA adduct levels in white blood cells and cotinine content in blood plasma, the latter being used as a marker for exposure to cigarette smoke.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. The Escherichia coli Tus-Ter replication fork barrier causes site-specific DNA replication perturbation in yeast

    DEFF Research Database (Denmark)

    Larsen, Nicolai B; Sass, Ehud; Suski, Catherine

    2014-01-01

    Replication fork (RF) pausing occurs at both 'programmed' sites and non-physiological barriers (for example, DNA adducts). Programmed RF pausing is required for site-specific DNA replication termination in Escherichia coli, and this process requires the binding of the polar terminator protein, Tus...... as a versatile, site-specific, heterologous DNA replication-perturbing system, with a variety of potential applications....

  8. Stability, accumulation and cytotoxicity of an albumin-cisplatin adduct

    DEFF Research Database (Denmark)

    Møller, Charlotte; Tastesen, Hanne Sørup; Gammelgaard, Bente

    2010-01-01

    The accumulation and cytotoxicity of a 10 µmol L¿¹ equimolar human serum albumin-cisplatin adduct (HSA-Pt) was investigated in suspension Ehrlich Ascites Tumor Cells (EATC) and adherent Ehrlich Lettré Ascites Cells (Lettré). HSA-Pt did not induce apoptosis nor was it taken up by the cells to any...... significant amount within 24 h incubation. The accumulation and cytotoxicity of HSA-Pt was compared to 10 µmol L¿¹ cisplatin for which a larger accumulation and cytotoxicity were observed in EATC compared to Lettré. The experiment was performed with cell medium exchange every fourth hour as HSA......-Pt and cisplatin were not stable in RPMI-1640 with 10% serum. The stability was determined using size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) and after 4 h new platinum peaks were observed. These findings indicate that before conducting cell experiments, the stability...

  9. Preparation and Characterization of Cysteine Adducts of Deoxynivalenol.

    Science.gov (United States)

    Stanic, Ana; Uhlig, Silvio; Solhaug, Anita; Rise, Frode; Wilkins, Alistair L; Miles, Christopher O

    2016-06-15

    Conjugation with the biologically relevant thiol glutathione is one of the metabolic pathways for the mycotoxin deoxynivalenol (DON) in wheat. The occurrence of putative DON-cysteine conjugates has also been shown in wheat, likely in part as a result of degradation of the glutathione conjugates. It was reported that thiols react in vitro with DON at two positions: reversibly at C-10 of the α,β-unsaturated ketone and irreversibly at C-13 of the epoxy group. We synthesized pure DON-cysteine adducts and made analytical standards using quantitative NMR experiments. Compounds were characterized using NMR and LC-HRMS/MS and tested in vitro for toxicity. Cysteine conjugates were much less toxic than DON at the same concentration, and LC-HRMS analysis demonstrated that there was no detectable metabolism of the conjugates in human monocytes or human macrophages.

  10. Paracetamol (acetaminophen) protein adduct concentrations during therapeutic dosing.

    Science.gov (United States)

    Heard, Kennon; Green, Jody L; Anderson, Victoria; Bucher-Bartelson, Becki; Dart, Richard C

    2016-03-01

    Paracetamol protein adducts (PPA) are a biomarker of paracetamol exposure. PPA are quantified as paracetamol-cysteine (APAP-CYS), and concentrations above 1.1 μmol l(-1) have been suggested as a marker of paracetamol-induced hepatotoxicity. However, there is little information on the range of concentrations observed during prolonged therapeutic dosing. The aim of the present study was to describe the concentration of PPA in the serum of subjects taking therapeutic doses of paracetamol for at least 16 days. Preplanned secondary aim of a prospective randomized controlled (placebo vs. 4g day(-1) paracetamol) trial. We measured subjects' serum PPA concentrations every 3 days for a minimum of 16 days. We also measured concentrations on study days 1-3 and 16-25 in subsets of patients. PPA were quantified as APAP-CYS after gel filtration and protein digestion using liquid chromatography/mass spectrometry. Ninety per cent of subjects had detectable PPA after five doses. Median APAP-CYS concentrations in paracetamol-treated subjects increased to a plateau of 0.1 μmol l(-1) on day 7, where they remained. The highest concentration measured was 1.1 μmol l(-1) and two subjects never had detectable PPA levels. PPA were detected in the serum of 78% of subjects 9 days after their final dose. PPA are detectable in the vast majority of subjects taking therapeutic doses of paracetamol. While most have concentrations well below the threshold associated with hepatotoxicity, concentrations may approach 1.1 μmol l(-1) in rare cases. Adducts are detectable after a few doses and can persist for over a week after dosing is stopped. © 2015 The British Pharmacological Society.

  11. DNA damage in internal organs after cutaneous exposure to sulphur mustard

    Energy Technology Data Exchange (ETDEWEB)

    Batal, Mohamed [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche, BP87, F-38702 La Tronche Cedex (France); Boudry, Isabelle; Mouret, Stéphane; Cléry-Barraud, Cécile; Wartelle, Julien [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche, BP87, F-38702 La Tronche Cedex (France); Bérard, Izabel [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Douki, Thierry, E-mail: thierry.douki@cea.fr [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France)

    2014-07-01

    Sulphur mustard (SM) is a chemical warfare agent that attacks mainly skin, eye and lungs. Due to its lipophilic properties, SM is also able to diffuse through the skin and reach internal organs. DNA represents one of the most critical molecular targets of this powerful alkylating agent which modifies DNA structure by forming monoadducts and biadducts. These DNA lesions are involved in the acute toxicity of SM as well as its long-term carcinogenicity. In the present work we studied the formation and persistence of guanine and adenine monoadducts and guanine biadducts in the DNA of brain, lungs, kidneys, spleen, and liver of SKH-1 mice cutaneously exposed to 2, 6 and 60 mg/kg of SM. SM-DNA adducts were detected in all studied organs, except in liver at the two lowest doses. Brain and lungs were the organs with the highest level of SM-DNA adducts, followed by kidney, spleen and liver. Monitoring the level of adducts for three weeks after cutaneous exposure showed that the lifetime of adducts were not the same in all organs, lungs being the organ with the longest persistence. Diffusion from skin to internal organs was much more efficient at the highest compared to the lowest dose investigated as the result of the loss of the skin barrier function. These data provide novel information on the distribution of SM in tissues following cutaneous exposures and indicate that brain is an important target. - Highlights: • Sulphur mustard reaches internal organs after skin exposure • Adducts are detected in the DNA of internal organs • Brain is the organ with the highest level of DNA damage • The barrier function of skin is lost at high dose of sulphur mustard • DNA adducts persist in organs for 2 or 3 weeks.

  12. DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity

    Directory of Open Access Journals (Sweden)

    Fabrizio Gentile

    2017-04-01

    Full Text Available Oxidative stress and lipid peroxidation (LPO induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity.

  13. Effect of exercise and gait retraining on knee adduction moment in people with knee osteoarthritis.

    Science.gov (United States)

    Khalaj, Nafiseh; Abu Osman, Noor A; Mokhtar, Abdul H; Mehdikhani, Mahboobeh; Wan Abas, Wan A B

    2014-02-01

    The knee adduction moment represents the medial knee joint load, and greater value is associated with higher load. In people with knee osteoarthritis, it is important to apply proper treatment with the least side effects to reduce knee adduction moment and, consequently, reduce medial knee joint load. This reduction may slow the progression of knee osteoarthritis. The research team performed a literature search of electronic databases. The search keywords were as follows: knee osteoarthritis, knee adduction moment, exercise program, exercise therapy, gait retraining, gait modification and knee joint loading. In total, 12 studies were selected, according to the selection criteria. Findings from previous studies illustrated that exercise and gait retraining programs could alter knee adduction moment in people with knee osteoarthritis. These treatments are noninvasive and nonpharmacological which so far have no or few side effects, as well as being low cost. The results of this review revealed that gait retraining programs were helpful in reducing the knee adduction moment. In contrast, not all the exercise programs were beneficial in reducing knee adduction moment. Future studies are needed to indicate best clinical exercise and gait retraining programs, which are most effective in reducing knee adduction moment in people with knee osteoarthritis.

  14. Electrophilic properties of patulin. Adduct structures and reaction pathways with 4-bromothiophenol and other model nucleophiles.

    Science.gov (United States)

    Fliege, R; Metzler, M

    2000-05-01

    The mycotoxin patulin (PAT) is believed to exert its cytotoxic and chromosome-damaging effects by forming covalent adducts with essential cellular thiols. Since the chemical structures of such adducts are unknown to date, we have studied the reaction of PAT and its O-acetylated derivative with the monofunctional thiol model compound 4-bromothiophenol (BTP), which was chosen due to analytical advantages. By means of analytical and preparative high-performance liquid chromatography, 16 adducts of PAT and 3 adducts of acetyl-PAT were isolated and their chemical structures elucidated by (1)H and (13)C NMR, IR, and UV spectroscopy. Time course studies and analysis of daughter product formation from isolated intermediate adducts led to a detailed scheme for the reaction of PAT with BTP. The structures of adducts of PAT formed with other model nucleophiles, e. g., the aliphatic thiol 2-mercaptoethanol and the aromatic amine 4-bromoaniline, were also elucidated and found to corroborate the reaction scheme. In addition, one further reaction pathway was observed with 2-mercaptoethanol, which appears to be independent from those found for BTP. Our study with model nucleophiles provides insights into the electrophilic reactivity of PAT and proved to be useful for the structure elucidation of PAT adducts with biological nucleophiles of toxicological relevance, as will be reported by Fliege and Metzler [(2000) Chem. Res. Toxicol. 13, 373-381].

  15. Analysis of hemoglobin adducts from acrylamide, glycidamide, and ethylene oxide in paired mother/cord blood samples from Denmark

    DEFF Research Database (Denmark)

    von Stedingk, Hans; Vikström, Anna C; Rydberg, Per

    2011-01-01

    The knowledge about fetal exposure to acrylamide/glycidamide from the maternal exposure through food is limited. Acrylamide, glycidamide, and ethylene oxide are electrophiles and form adducts with hemoglobin (Hb), which could be used for in vivo dose measurement. In this study, a method...... for analysis of Hb adducts by liquid chromatography-mass spectrometry, the adduct FIRE procedure, was applied to measurements of adducts from these compounds in maternal blood samples (n = 87) and umbilical cord blood samples (n = 219). The adduct levels from the three compounds, acrylamide, glycidamide......, and ethylene oxide, were increased in tobacco smokers. Highly significant correlations were found between cord and maternal blood with regard to measured adduct levels of the three compounds. The mean cord/maternal hemoglobin adduct level ratios were 0.48 (range 0.27-0.86) for acrylamide, 0.38 (range 0...

  16. Synthesis, properties, and NMR studies of a C8-phenylguanine modified oligonucleotide that preferentially adopts the Z DNA conformation.

    Science.gov (United States)

    Gannett, Peter M; Heavner, Sue; Daft, Jonathan R; Shaughnessy, Kevin H; Epperson, Jon D; Greenbaum, Nancy L

    2003-10-01

    Carcinogenic aryl hydrazines produce C8-arylated purine adducts. The effect of these adducts on DNA conformation and their role in hydrazine carcinogenesis are unknown. Here, we describe a new synthetic route to produce these adducts that is also compatible with the synthesis of the corresponding phosphoramidites needed for oligonucleotide synthesis. Two oligonucleotides were prepared, an unmodified oligonucleotide, d((5)(')CGCGCGCGCG(3)(')), and a C8-phenylguanine modified oligonucleotide, d((5)(')CGCGCGCGCG(3)(')) (G = 8-phenylguanine). These oligonucleotides were compared using thermal denaturation, circular dichroism, NMR, and molecular modeling. The phenyl modification destabilizes the B DNA form and stabilizes the Z DNA form such that the B:Z ratio is near one under physiological conditions. In light of recent studies that show a role for Z DNA in gene expression and cell transformation, Z DNA stabilization by C8-arylguanine formation from aryl hydrazines may be relevant to their role in carcinogenesis.

  17. Repair of DNA treated with. gamma. -irradiation and chemical carcinogens. Progress report, 1980-1983

    Energy Technology Data Exchange (ETDEWEB)

    Goldthwait, D.A.

    1984-02-01

    We have studied in vitro DNA repair with the isolation and characterization of DNA glycosylases active in the removable of 3-methyladenine and the problem of repair of DNA in chromatin. The second area of focus has been on transposable elements and carcinogen action. The work on DNA adducts with ..beta..-propiolactone was done to define potential new substrates useful in a search for new glycosylases.

  18. Crosstalk between Translesion Synthesis, Fanconi Anemia Network, and Homologous Recombination Repair Pathways in Interstrand DNA Crosslink Repair and Development of Chemoresistance

    OpenAIRE

    Haynes, Brittany; Saadat, Nadia; Myung, Brian; Shekhar, Malathy PV

    2014-01-01

    Bifunctional alkylating and platinum based drugs are chemotherapeutic agents used to treat cancer. These agents induce DNA adducts via formation of intrastrand or interstrand (ICL) DNA crosslinks, and DNA lesions of the ICL type are particularly toxic as they block DNA replication and/or DNA transcription. However, the therapeutic efficacies of these drugs are frequently limited due to the cancer cell’s enhanced ability to repair and tolerate these toxic DNA lesions. This ability to tolerate ...

  19. NEW THIO S2- ADDUCTS WITH ANTIMONY (III AND V HALIDE: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    HASSAN ALLOUCH

    2013-12-01

    Full Text Available Five new S2- adducts with SbIII and SbV halides have been synthesized and studied by infrared. Discrete structures have been suggested, the environment around the antimony being tetrahedral, trigonal bipyramidal or octahedral.

  20. Biological monitoring in workers in a nitrobenzene reduction plant: haemoglobin versus serum albumin adducts.

    Science.gov (United States)

    Thier, R; Lewalter, J; Selinski, S; Bolt, H M

    2001-09-01

    The high priority of monitoring workers exposed to nitrobenzene is a consequence of clear findings of experimental carcinogenicity of nitrobenzene and the associated evaluations by the International Agency for Research on Cancer. Eighty male employees of a nitrobenzene reduction plant, with potential skin contact with nitrobenzene and aniline, participated in a current medical surveillance programme. Blood samples were routinely taken and analysed for aniline, 4-aminodiphenyl (4-ADP) and benzidine adducts of haemoglobin (Hb) and human serum albumin (HSA). Also, levels of methaemoglobin (Met-Hb) and of carbon monoxide haemoglobin (CO-Hb) were monitored. Effects of smoking were straightforward. Using the rank sum test of Wilcoxon, we found that very clear-cut and statistically significant smoking effects (about 3-fold increases) were apparent on CO-Hb (P = 0.00085) and on the Hb adduct of 4-ADP (P = 0.0006). The mean aniline-Hb adduct level in smokers was 1.5 times higher than in non-smokers; the significance (P = 0.05375) was close to the 5% level. The strongest correlation was evident between the Hb and HSA adducts of aniline (r(s) = 0.846). Less pronounced correlations (but with P values aniline-Hb and 4-ADP-Hb adducts (r(s) = 0.388), between 4-ADP and 4-ADP-HSA adducts (r(s) = 0.373), and between 4-ADP-Hb and aniline-HSA adducts (r(s) = 0.275). In view of the proposal for additional use of the aniline-HSA adduct for biological monitoring, particularly in cases of acute overexposures or poisonings, the strong correlation of the Hb and HSA conjugates is noteworthy; the ratio aniline-HSA:aniline-Hb was 1:42 for the entire cohort.

  1. Factors influencing knee adduction moment measurement: A systematic review and meta-regression analysis.

    Science.gov (United States)

    Telfer, Scott; Lange, Moritz J; Sudduth, Amanda S M

    2017-10-01

    The external knee adduction moment has been identified as a key biomarker in biomechanics research, with associations with this variable and degenerative diseases such as knee osteoarthritis. Heterogeneity in participant characteristics and the protocols used to measure this variable may however complicate its interpretation. Previous reviews have focused on interventions or did not control for potential moderator variables in their analysis. In this meta-regression analysis, we aimed to determine the influence of factors including the cohort type, footwear, and walking speed on the measurement of knee adduction moment. We performed a systematic review of the literature, identifying articles that used the Plug-in-Gait inverse dynamics model to calculate the knee adduction moment during level walking, and used a mixed effect model to determine the effect of the previously described factors on the measurement. Results for 861 individuals were described in 19 articles. Walking speed had the largest influence on knee adduction moment (p<0.001), and participants with medial knee osteoarthritis had an increased knee adduction moment (p=0.008) compared to healthy subjects. Footwear was found to have a significant overall effect (p=0.024). Participants tested barefoot or wearing their own shoes had lower adduction moments than those tested in footwear provided by the researchers. Overall, the moderators accounted for 60% of the heterogeneity in the results. These results support the hypothesis that an increased knee adduction moment is associated with medial compartment knee osteoarthritis, and that footwear choice can influence the results. Gait speed has the largest effect on knee adduction moment measurement and should be carefully controlled for in studies investigating this variable. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Cellulose based hybrid hydroxylated adducts for polyurethane foams

    Science.gov (United States)

    De Pisapia, Laura; Verdolotti, Letizia; Di Mauro, Eduardo; Di Maio, Ernesto; Lavorgna, Marino; Iannace, Salvatore

    2012-07-01

    Hybrid flexible polyurethane foams (HPU) were synthesized by using a hybrid hydroxilated adduct (HHA) based on renewable resources. In particular the HHA was obtained by dispersing cellulose wastes in colloidal silica at room temperature, pressure and humidity. The colloidal silica was selected for its ability of modifying the cellulose structure, by inducing a certain "destructurization" of the crystalline phase, in order to allow cellulose to react with di-isocyanate for the final synthesis of the polyurethane foam. In fact, cellulose-polysilicate complexes are engaged in the reaction with the isocyanate groups. This study provides evidence of the effects of the colloidal silica on the cellulose structure, namely, a reduction of the microfiber cellulose diameter and the formation of hydrogen bonds between the polysilicate functional groups and the hydroxyl groups of the cellulose, as assessed by IR spectroscopy and solid state NMR. The HHA was added to a conventional polyol in different percentages (between 5 and 20%) to synthesize HPU in presence of catalysts, silicone surfactant and diphenylmethane diisocyanate (MDI). The mixture was expanded in a mold and cured for two hours at room temperature. Thermal analysis, optical microscopy and mechanical tests were performed on the foams. The results highlighted an improvement of thermal stability and a decrease of the cell size with respect neat polyurethane foam. Mechanical tests showed an improvement of the elastic modulus and of the damping properties with increasing HHA amount.

  3. Chemistry and Chemical Equilibrium Dynamics of BMAA and Its Carbamate Adducts.

    Science.gov (United States)

    Diaz-Parga, Pedro; Goto, Joy J; Krishnan, V V

    2018-01-01

    Beta-N-methylamino-L-alanine (BMAA) has been demonstrated to contribute to the onset of the ALS/Parkinsonism-dementia complex (ALS/PDC) and is implicated in the progression of other neurodegenerative diseases. While the role of BMAA in these diseases is still debated, one of the suggested mechanisms involves the activation of excitatory glutamate receptors. In particular, the excitatory effects of BMAA are shown to be dependent on the presence of bicarbonate ions, which in turn forms carbamate adducts in physiological conditions. The formation of carbamate adducts from BMAA and bicarbonate is similar to the formation of carbamate adducts from non-proteinogenic amino acids. Structural, chemical, and biological information related to non-proteinogenic amino acids provide insight into the formation of and possible neurological action of BMAA. This article reviews the carbamate formation of BMAA in the presence of bicarbonate ions, with a particular focus on how the chemical equilibrium of BMAA carbamate adducts may affect the molecular mechanism of its function. Highlights of nuclear magnetic resonance (NMR)-based studies on the equilibrium process between free BMAA and its adducts are presented. The role of divalent metals on the equilibrium process is also explored. The formation and the equilibrium process of carbamate adducts of BMAA may answer questions on their neuroactive potency and provide strong motivation for further investigations into other toxic mechanisms.

  4. Identification of Rosmarinic Acid-Adducted Sites in Meat Proteins in a Gel Model under Oxidative Stress by Triple TOF MS/MS.

    Science.gov (United States)

    Tang, Chang-Bo; Zhang, Wan-Gang; Wang, Yao-Song; Xing, Lu-Juan; Xu, Xing-Lian; Zhou, Guang-Hong

    2016-08-24

    Triple TOF MS/MS was used to identify adducts between rosmarinic acid (RosA)-derived quinones and meat proteins in a gel model under oxidative stress. Seventy-five RosA-modified peptides responded to 67 proteins with adduction of RosA. RosA conjugated with different amino acids in proteins, and His, Arg, and Lys adducts with RosA were identified for the first time in meat. A total of 8 peptides containing Cys, 14 peptides containing His, 48 peptides containing Arg, 64 peptides containing Lys, and 5 peptides containing N-termini that which participated in adduction reaction with RosA were identified, respectively. Seventy-seven adduction sites were subdivided into all adducted proteins including 2 N-terminal adduction sites, 3 Cys adduction sites, 4 His adduction sites, 29 Arg adduction sites, and 39 Lys adduction sites. Site occupancy analyses showed that approximately 80.597% of the proteins carried a single RosA-modified site, 14.925% retained two sites, 1.492% contained three sites, and the rest 2.985% had four or more sites. Large-scale triple TOF MS/MS mapping of RosA-adducted sites reveals the adduction regulations of quinone and different amino acids as well as the adduction ratios, which clarify phenol-protein adductions and pave the way for industrial meat processing and preservation.

  5. Revisiting the stability of endo/exo Diels-Alder adducts between cyclopentadiene and 1,4-benzoquinone

    Energy Technology Data Exchange (ETDEWEB)

    Tormena, Claudio F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Lacerda Junior, Valdemar [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. Dept. de Quimica; Oliveira, Kleber T. de [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas

    2010-07-01

    In this work it is presented a detailed theoretical analysis of the relative stability of endo/exo Diels-Alder adducts formed by the reaction between cyclopentadiene (1) and 1,4-benzoquinone (2). The intrinsic reaction coordinate (IRC) showed the existence of only one transition state for the reaction studied, for both endo 3 and exo 4 adducts. The energies of both adducts were obtained at high level of theory (CBS-Q) confirming that the endo adduct is more stable than exo, which is in the opposite way to the observed in reactions that usually follow Alder's rule. An electronic structure analysis was performed through NBO methodology, indicating that the attractive delocalization interaction predominates over the steric repulsive interaction in the endo adducts. In summary, for the studied cycloaddition reaction the endo adduct is the thermodynamic and kinetic product, which can be also confirmed by experimental data mentioned in this work. (author)

  6. Consequences of quercetin methylation for its covalent glutathione and DNA adduct formation

    NARCIS (Netherlands)

    Woude, van der H.; Boersma, M.G.; Alink, G.M.; Vervoort, J.J.M.; Rietjens, I.M.C.M.

    2006-01-01

    This study investigates the pro-oxidant activity of 3¿- and 4¿-O-methylquercetin, two relevant phase II metabolites of quercetin without a functional catechol moiety, which is generally thought to be important for the pro-oxidant activity of quercetin. Oxidation of 3¿- and 4¿-O-methylquercetin with

  7. Two food-borne heterocyclic amines: Metabolism and DNA adduct formation of amino-alpha-carbolines

    DEFF Research Database (Denmark)

    Frederiksen, Hanne

    2005-01-01

    or proteins of animal or vegetable origin, furthermore they are found in many cooked foods, such as fish, meat, and chicken. The specific mutagenicity of the amino-a-carbolines are lower in the Ames Salmonella assay than other heterocyclic amines, but in rodent studies the carcinogenicity of the aminoa, alpha...

  8. Quantification of acylfulvene- and illudin S-DNA adducts in cells with variable bioactivation capacities

    OpenAIRE

    Pietsch, Kathryn E.; van Midwoud, Paul M.; Villalta, Peter W.; Sturla, Shana J.

    2012-01-01

    Illudin S and its semi-synthetic analogue acylfulvene are structurally similar but elicit different biological responses. AF is a bioreductive alkylating anti-cancer agent with a favorable therapeutic index, while illudin S is in general highly toxic. AF toxicity is dependent on the reductase enzyme prostaglandin reductase 1 (PTGR1) for activation to a cytotoxic reactive intermediate. While illudin S can be metabolized by PTGR1, available data suggest that its toxicity does not correspond wit...

  9. Protein adducts as biomarkers of exposure to aromatic diisocyanates in workers manufacturing polyurethane (PUR) foam.

    Science.gov (United States)

    Säkkinen, Kirsi; Tornaeus, Jarkko; Hesso, Antti; Hirvonen, Ari; Vainio, Harri; Norppa, Hannu; Rosenberg, Christina

    2011-04-01

    This work was undertaken to investigate the usefulness of diisocyanate-related protein adducts in blood samples as biomarkers of occupational exposure to toluene diisocyanate (TDI; 2,4- and 2,6-isomers) and 4,4'-methylenediphenyl diisocyanate (MDI). Quantification of adducts as toluene diamines (TDAs) and methylenedianiline (MDA) was performed on perfluoroacylated derivatives by gas chromatography-mass spectrometry (GC-MS/MS) in negative chemical ionisation mode. TDI-derived adducts were found in 77% of plasma and in 59% of globin samples from exposed workers manufacturing flexible polyurethane foam. The plasma levels ranged from 0.003 to 0.58 nmol mL(-1) and those in globin from 0.012 to 0.33 nmol g(-1). The 2,6-isomer amounted to about two-thirds of the sum concentration of TDA isomers. MDI-derived adducts were detected in 3.5% of plasma and in 7% of globin samples from exposed workers manufacturing rigid polyurethane foam. A good correlation was found between the sum of TDA isomers in urine and that in plasma. The relationship between globin adducts and urinary metabolites was ambiguous. Monitoring TDI-derived TDA in plasma thus appears to be an appropriate method for assessing occupational exposure. Contrary to TDI exposure, adducts in plasma or globin were not useful in assessing workers' exposure to MDI. An important outcome of the study was that no amine-related adducts were detected in globin samples from TDI- or MDI-exposed workers, alleviating concerns that TDI or MDI might pose a carcinogenic hazard. Further studies are nevertheless required to judge whether diisocyanates per se could be such a hazard.

  10. Radiomodifying effects of RAPTA C and CDDP on DNA strand break induction

    Science.gov (United States)

    Reimitz, Dan; Davídková, Marie; Mestek, Oto; Pinkas, Jiří; Kočišek, Jaroslav

    2017-12-01

    Experimental study is exploring combined effect of RAPTA C (Ru(η6-p-cymene)Cl2(1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decanephosphine)) or CDDP (cis-diamminedichloridoplatinum(II)) and radiation on the DNA damage. When irradiating plasmid DNA in solution with free molecules, no combined effect is observed, indicating that the contribution to DNA damage caused by products of radiolysis of RAPTA C or CDDP is negligible in comparison to the damage caused by products of radiolysis of water. After binding to DNA, CDDP adducts with DNA strongly enhance the damage in a good agreement with the results of previous studies. RAPTA C adducts act radio-protective at low doses of OH radical scavenger - tris(hydroxymethyl)aminomethane (tris) and show no combined effects at higher tris levels. Radioprotectivity of RAPTA C is therefore primarily caused by enhanced resistance of RAPTA C modified DNA against the damage induced by radicals.

  11. Nitroreduction and formation of hemoglobin adducts in rats with a human intestinal microflora

    Energy Technology Data Exchange (ETDEWEB)

    Scheepers, P.T.J.; Straetemans, M.M.E.; Koopman, J.P.; Bos, R.P. [Univ. of Nijmegen (Netherlands)

    1994-10-01

    In the covalent binding of nitroarenes to macromolecules, nitroreduction is an important step. The intestinal microflora represents an enormous potential of bacterial nitroreductase activity. As a consequence, the in vivo nitroreduction of orally administerednitroarenes is primarily located in the intestine. In this study, we have investigated the nitroreduction of 2-nitrofluorene (2-NF) by a human microflora in female Wistar rats. Germ-free (FG) rats were equipped with a bacterial flora derived from human feces. Nontreated GF rats and GF animals equipped with a conventional rat flora were used as controls. The composition of the human and the conventional microflora isolated from the rats were consistent with the microflora of the administered feces. In the rats receiving only sunflower seed oil, no adducts were detected. The animals equipped with a human or rat microflora that received 2-aminofluorene (2-AF) formed 2-AF hemoglobin (Hb)-adducts at average levels mean {+-} 0.003 and 0.043 {+-} 0.010 {mu}mole/g Hb, respectively. In the FG rats, an adduct level of 0.57 {+-} 0.09 was determined after 2-AF administration and non adducts were detected after 2-NF administration. The results show that nitroreduction by an acquired human intestinal microflora and subsequent adduct formation can be studied in the rate in vivo. 21 refs., 3 tabs.

  12. Acetaminophen-cysteine adducts during therapeutic dosing and following overdose

    Directory of Open Access Journals (Sweden)

    Judge Bryan S

    2011-03-01

    Full Text Available Abstract Background Acetaminophen-cysteine adducts (APAP-CYS are a specific biomarker of acetaminophen exposure. APAP-CYS concentrations have been described in the setting of acute overdose, and a concentration >1.1 nmol/ml has been suggested as a marker of hepatic injury from acetaminophen overdose in patients with an ALT >1000 IU/L. However, the concentrations of APAP-CYS during therapeutic dosing, in cases of acetaminophen toxicity from repeated dosing and in cases of hepatic injury from non-acetaminophen hepatotoxins have not been well characterized. The objective of this study is to describe APAP-CYS concentrations in these clinical settings as well as to further characterize the concentrations observed following acetaminophen overdose. Methods Samples were collected during three clinical trials in which subjects received 4 g/day of acetaminophen and during an observational study of acetaminophen overdose patients. Trial 1 consisted of non-drinkers who received APAP for 10 days, Trial 2 consisted of moderate drinkers dosed for 10 days and Trial 3 included subjects who chronically abuse alcohol dosed for 5 days. Patients in the observational study were categorized by type of acetaminophen exposure (single or repeated. Serum APAP-CYS was measured using high pressure liquid chromatography with electrochemical detection. Results Trial 1 included 144 samples from 24 subjects; Trial 2 included 182 samples from 91 subjects and Trial 3 included 200 samples from 40 subjects. In addition, we collected samples from 19 subjects with acute acetaminophen ingestion, 7 subjects with repeated acetaminophen exposure and 4 subjects who ingested another hepatotoxin. The mean (SD peak APAP-CYS concentrations for the Trials were: Trial 1- 0.4 (0.20 nmol/ml, Trial 2- 0.1 (0.09 nmol/ml and Trial 3- 0.3 (0.12 nmol/ml. APAP-CYS concentrations varied substantially among the patients with acetaminophen toxicity (0.10 to 27.3 nmol/ml. No subject had detectable APAP

  13. Acetaminophen-cysteine adducts during therapeutic dosing and following overdose

    Science.gov (United States)

    2011-01-01

    Background Acetaminophen-cysteine adducts (APAP-CYS) are a specific biomarker of acetaminophen exposure. APAP-CYS concentrations have been described in the setting of acute overdose, and a concentration >1.1 nmol/ml has been suggested as a marker of hepatic injury from acetaminophen overdose in patients with an ALT >1000 IU/L. However, the concentrations of APAP-CYS during therapeutic dosing, in cases of acetaminophen toxicity from repeated dosing and in cases of hepatic injury from non-acetaminophen hepatotoxins have not been well characterized. The objective of this study is to describe APAP-CYS concentrations in these clinical settings as well as to further characterize the concentrations observed following acetaminophen overdose. Methods Samples were collected during three clinical trials in which subjects received 4 g/day of acetaminophen and during an observational study of acetaminophen overdose patients. Trial 1 consisted of non-drinkers who received APAP for 10 days, Trial 2 consisted of moderate drinkers dosed for 10 days and Trial 3 included subjects who chronically abuse alcohol dosed for 5 days. Patients in the observational study were categorized by type of acetaminophen exposure (single or repeated). Serum APAP-CYS was measured using high pressure liquid chromatography with electrochemical detection. Results Trial 1 included 144 samples from 24 subjects; Trial 2 included 182 samples from 91 subjects and Trial 3 included 200 samples from 40 subjects. In addition, we collected samples from 19 subjects with acute acetaminophen ingestion, 7 subjects with repeated acetaminophen exposure and 4 subjects who ingested another hepatotoxin. The mean (SD) peak APAP-CYS concentrations for the Trials were: Trial 1- 0.4 (0.20) nmol/ml, Trial 2- 0.1 (0.09) nmol/ml and Trial 3- 0.3 (0.12) nmol/ml. APAP-CYS concentrations varied substantially among the patients with acetaminophen toxicity (0.10 to 27.3 nmol/ml). No subject had detectable APAP-CYS following exposure to

  14. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  15. Rotational Investigation of the Adducts of Formic Acid with Alcohols, Ethers and Esters

    Science.gov (United States)

    Evangelisti, Luca; Spada, Lorenzo; Li, Weixing; Caminati, Walther

    2016-06-01

    Mixtures of formic acid with methyl alcohol, with isopropyl alcohol, with tert-butyl alcohol, with dimethylether and with isopropylformiate have been supersonically expanded as pulsed jets. The obtained cool plumes have been analyzed by Fourier transform microwave spectroscopy. It has been possible to assign the rotational spectra of the 1:1 adducts of formic acid with tert-butyl alcohol, with dimethyl ether and with isopropylformiate. The conformational shapes and geometries of these adducts, as well as the topologies of their itermolecular hydrogen bonds will be presented. An explanation is given of the failure of the assignments of the rotational spectra of the adducts of formic acid with methyl alcohol and isopropyl alcohol.

  16. DFT Study on the Co-Xe Bond in the HCo(CO3Xe Adduct

    Directory of Open Access Journals (Sweden)

    Tamás Kégl

    2014-01-01

    Full Text Available The metal-xenon interaction has been studied in hydrido-cobalt-carbonyl complexes by means of density functional methods. The method of choice has been selected after testing various functionals including dispersion correction on the bond dissociation enthalpy of Xe in the Cr(CO5Xe adduct. In general, the long range corrected versions of popular gradient-corrected functionals performed well. In particular, LC-mPWPW91 resulted in a perfect match with available experimental data; therefore this functional was selected for the computation of HCo(CO3Xe adducts. For HCo(CO3Xe two isomers have been located; the structure with CS symmetry has proved to be more stable by 5.3 kcal/mol than the C3V adduct in terms of free energy. The formation of HCo(CO3Xe is, however, endergonic by 3.5 kcal/mol for the CS isomer.

  17. Isomerism and adduct formation in the hector's base series: A MNDO study of model compounds

    Science.gov (United States)

    Cuthbertson, Alastair F.; Glidewell, Christopher

    MNDO calculations on a series of a model compounds show that the observed structures for Hector's base, Dost's base and Dost's keto compound are the thermodynamically most stable tautomers and that the bond-switched structure observed for the 1:1 adduct of Hector's base with carbon disulphide and the non-bond-switched structure observed for the corresponding adducts with isocyanates and isothiocyanates are both the thermodynamically most favoured isomers, so that the occurrence or otherwise of a bond switch in these compounds is determined by thermodynamic rather than by mechanistic factors. Proposed mechanisms for the formation of the carbon disulphide adduct of Hector's base, and for its desulphurisation are supported by MNDO calculations.

  18. A novel organo-zeolite adduct for environmental applications: sorption of phenol.

    Science.gov (United States)

    Leone, V; Canzano, S; Iovino, P; Salvestrini, S; Capasso, S

    2013-04-01

    A novel organo-zeolite adduct has been synthesized by sorbing humic acids (HA) onto zeolitic tuff and then heating the resulting complex at 330°C for 1.5h. Desorption tests showed that this procedure effectively immobilized HA on the tuff. The crystal structure of the zeolitic tuff and the chemical structure of HA were not altered during the preparation. Phenol sorption analysis demonstrated that the HA-zeolite adduct had good sorbing properties; moreover, the sorbed amount markedly decreased with increased ionic strength. These results point to prospective application of the HA-zeolite adduct as a low-cost and environmentally friendly sorbent for water purification from phenol and possibly other neutral organic pollutants. Copyright © 2013. Published by Elsevier Ltd.

  19. Thermally cleavable Imine Base / Isocyanate Adducts and Oligomers suitable as Initiators for Radical Homo- and Copolymerization

    OpenAIRE

    Polenz, Ingmar; Laue, Andreas; Uhrin, Tamas; Rueffer, Tobias; Lang, Heinrich; Schmidt, Friedrich; Spange, Stefan

    2014-01-01

    The addition of isocyanates to C=N double bonds of imines gives triazindione heterocycle structures; their thermal properties are reported. Mono-isocyanates were used to form 2:1 adducts with the imine bases 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and 2-tert-butyl-1,1,3,3-tetramethylguanidine (tBuTMG). A 2:1 stoichiometry of the adducts was proven by NMR and IR spectroscopy, and single crystal X-Ray diffraction; certain cleavage temperatures (70 and 16...

  20. Sodiated Sugar Structures: Cryogenic Ion Vibrational Spectroscopy of Na^+(GLUCOSE) Adducts

    Science.gov (United States)

    Voss, Jonathan; Kregel, Steven J.; Fischer, Kaitlyn C.; Garand, Etienne

    2017-06-01

    The recent discovery that ionic liquids help facilitate the dissolution of cellulose has renewed interest in understanding how ionic species interact with carbohydrates. Here we present infrared spectra in the 2800 - 3800 \\wn range of gas-phase mass-selected Na^+(Glucose) adducts. These adducts are further probed with IR-dip spectroscopy to yield conformer specific spectra of at least seven unique species. The relative abundances of conformers show that gas-phase interconversion barriers are sufficiently high to preserve the solution-phase populations. Additionally, our results demonstrate that mM concentrations of NaCl do not strongly perturb the anomeric ratio of glucose in solution.

  1. Large eccentric strength increase using the Copenhagen Adduction exercise in football

    DEFF Research Database (Denmark)

    Ishøi, L; Sørensen, C N; Kaae, N M

    2016-01-01

    Hip adductor injuries are frequent in football, and players with low adductor strength appear to be at increased risk of injury. High adductor muscle activity has been shown in the Copenhagen Adduction exercise (CA); however, an associated strength gain has not been investigated. This study aims...... to examine the eccentric hip adduction strength (EHAD) gain using the CA in-season. Two U-19 sub-elite football teams, including 24 football players, were randomized to either an 8-week supervised progressive training program in addition to the usual training (intervention) or to continue training as usual...

  2. Bulky DNA adducts, 4-aminobiphenyl-haemoglobin adducts and diet in the European Prospective Investigation into Cancer and Nutrition (EPIC) prospective study

    NARCIS (Netherlands)

    Peluso, Marco; Alroldi, Luisa; Munnia, Armelle; Colombi, Alessandro; Veglia, Fabrizio; Autrup, Herman; Dunning, Alison; Garte, Seymour; Gormally, Emmanuelle; Malaveille, Christian; Matullo, Giuseppe; Overvad, Kim; Raaschou-Nielsen, Ole; Clavel-Chapelon, Francoise; Linseisen, Jacob; Boeing, Heiner; Trichopoulou, Antonia; Palli, Domenico; Krogh, Vittorio; Tumino, Rosario; Panico, Salvatore; Bueno-De-Mesquita, Bas H.; Peeters, Petra H.; Kumle, Merethe; Agudo, Antonio; Martinez, Carmen; Dorronsoro, Miren; Barricarte, Aurelio; Tormo, Maria Jose; Quiros, Jose Ramon; Berglund, Goran; Jarvholm, Bengt; Day, Nicholas E.; Key, Timothy J.; Saracci, Rodolfo; Kaaks, Rudolf; Riboli, Elio; Bingham, Shelia; Vineis, Paolo

    In contrast to some extensively examined food mutagens, for example, aflatoxins, N-nitrosamines and heterocyclic amines, some other food contaminants, in particular polycyclic aromatic hydrocarbons (PAH) and other aromatic compounds, have received less attention. Therefore, exploring the

  3. Cresyl saligenin phosphate makes multiple adducts on free histidine, but does not form an adduct on histidine 438 of human butyrylcholinesterase

    OpenAIRE

    Liyasova, Mariya S.; Schopfer, Lawrence M.; Lockridge, Oksana

    2012-01-01

    Cresyl saligenin phosphate (CBDP) is a suspected causative agent of “aerotoxic syndrome”, affecting pilots, crew members and passengers. CBDP is produced in vivo from ortho-containing isomers of tricresyl phosphate (TCP), a component of jet engine lubricants and hydraulic fluids. CBDP irreversibly inhibits butyrylcholinesterase (BChE) in human plasma by forming adducts on the active site serine (Ser-198). Inhibited BChE undergoes aging to release saligenin and o-cresol. The active site histid...

  4. Observed adducts on positive mode direct analysis in real time mass spectrometry - Proton/ammonium adduct selectivities of 600-sample in-house chemical library.

    Science.gov (United States)

    Sugimura, Natsuhiko; Furuya, Asami; Yatsu, Takahiro; Igarashi, Yoko; Aoyama, Reiko; Izutani, Chisato; Yamamoto, Yorihiro; Shibue, Toshimichi

    2017-02-01

    In this study, direct analysis in real time adduct selectivities of a 558 in-house high-resolution mass spectrometry sample library was evaluated. The protonated molecular ion ([M + H]+) was detected in 462 samples. The ammonium adduct ion ([M + NH4]+) was also detected in 262 samples. [M + H]+ and [M + NH4]+ molecular ions were observed simultaneously in 166 samples. These adduct selectivities were related to the elemental compositions of the sample compounds. [M + NH4]+ selectivity correlated with the number of oxygen atom(s), whereas [M + H]+ selectivity correlated with the number of nitrogen atom(s) in the elemental compositions. For compounds including a nitrogen atom and an oxygen atom [M + H]+ was detected; [M + NH4]+ was detected for compounds including an oxygen atom only. Density functional theory calculations were performed for selected library samples and model compounds. Energy differences were observed between compounds detected as [M + H]+ and [M + NH4]+, and between compounds including a nitrogen atom and an oxygen atom in their elemental compositions. The results suggested that the presence of oxygen atoms stabilizes [M + NH4]+, but not every oxygen atom has enough energy for detection of [M + NH4]+. It was concluded that the nitrogen atom(s) and oxygen atom(s) in the elemental compositions play important roles in the adduct formation in direct analysis in real time mass spectrometry.

  5. Boron Difluoride Adducts of a Flexidentate Pyridine-Substituted Formazanate Ligand: Property Modulation via Protonation and Coordination Chemistry.

    Science.gov (United States)

    Barbon, Stephanie M; Buddingh, Jasmine V; Maar, Ryan R; Gilroy, Joe B

    2017-10-02

    The synthesis and characterization of a flexidentate pyridine-substituted formazanate ligand and its boron difluoride adducts, formed via two different coordination modes of the title ligand, are described. The first adduct adopted a structure that was typical of other boron difluoride adducts of triarylformazanate ligands and contained a free pyridine subsituent, while the second was formed via the chelation of nitrogen atoms from the formazanate backbone and the pyridine substituent. Stepwise protonation of the pydridine-functionalized adduct, which is essentially nonemissive, resulted in a significant increase in the fluorescence quantum yield up to a maximum of 18%, prompting the study of this adduct as a pH sensor. The coordination chemistry of each adduct was explored through reactions with nickel(II) bromide [NiBr 2 (CH 3 CN) 2 ], triflate [Ni(OTf) 2 ], and 1,1,1,4,4,4-hexafluoroacetylacetonate [Ni(hfac) 2 (H 2 O) 2 ] salts. Coordination to nickel(II) ions altered the physical properties of the boron difluoride formazanate adducts, including red-shifted absorption maxima and less negative reduction potentials. Together, these studies have demonstrated that the physical and electronic properties of boron difluoride adducts of formazanate ligands can be readily modulated through protonation and coordination chemistry.

  6. Identification and quantification of drug-albumin adducts in serum samples from a drug exposure study in mice

    NARCIS (Netherlands)

    Switzar, L.; Kwast, L.M.; Lingeman, H.; Giera, M.; Pieters, R.H.H.; Niessen, W.M.A.

    2013-01-01

    The formation of drug-protein adducts following the bioactivation of drugs to reactive metabolites has been linked to adverse drug reactions (ADRs) and is a major complication in drug discovery and development. Identification and quantification of drug-protein adducts in vivo may lead to a better

  7. Measurement of HNE-protein adducts in human plasma and serum by ELISA—Comparison of two primary antibodies

    Directory of Open Access Journals (Sweden)

    Daniela Weber

    2013-01-01

    After modification and validation of the protocol for both antibodies, samples of two groups were analyzed: apparently healthy obese (n=62 and non-obese controls (n=15. Although the detected absolute values of HNE–protein adducts were different, depending on the antibody used, both ELISA methods showed significantly higher values of HNE–protein adducts in the obese group.

  8. Validation of a food frequency questionnaire measurement of dietary acrylamide intake using hemoglobin adducts of acrylamide and glycidamide

    Science.gov (United States)

    Wilson, Kathryn M.; Vesper, Hubert W.; Tocco, Paula; Sampson, Laura; Rosén, Johan; Hellenäs, Karl-Erik; Törnqvist, Margareta; Willett, Walter C.

    2011-01-01

    Objective Acrylamide, a probable human carcinogen, is formed during high-heat cooking of many common foods. The validity of food frequency questionnaire (FFQ) measures of acrylamide intake has not been established. We assessed the validity of acrylamide intake calculated from an FFQ using a biomarker of acrylamide exposure. Methods We calculated acrylamide intake from an FFQ in the Nurses' Health Study II. We measured hemoglobin adducts of acrylamide and its metabolite, glycidamide, in a random sample of 296 women. Correlation and regression analyses were used to assess the relationship between acrylamide intake and adducts. Results The correlation between acrylamide intake and the sum of acrylamide and glycidamide adducts was 0.31 (95% CI: 0.20 – 0.41), adjusted for laboratory batch, energy intake, and age. Further adjustment for BMI, alcohol intake, and correction for random within-person measurement error in adducts gave a correlation of 0.34 (CI: 0.23 – 0.45). The intraclass correlation coefficient for the sum of adducts was 0.77 in blood samples collected 1 to 3 years apart in a subset of 45 women. Intake of several foods significantly predicted adducts in multiple regression. Conclusions Acrylamide intake and hemoglobin adducts of acrylamide and glycidamide were moderately correlated. Within-person consistency in adducts was high over time. PMID:18855107

  9. Base damage, local sequence context and TP53 mutation hotspots: a molecular dynamics study of benzo[a]pyrene induced DNA distortion and mutability.

    Science.gov (United States)

    Menzies, Georgina E; Reed, Simon H; Brancale, Andrea; Lewis, Paul D

    2015-10-30

    The mutational pattern for the TP53 tumour suppressor gene in lung tumours differs to other cancer types by having a higher frequency of G:C>T:A transversions. The aetiology of this differing mutation pattern is still unknown. Benzo[a]pyrene,diol epoxide (BPDE) is a potent cigarette smoke carcinogen that forms guanine adducts at TP53 CpG mutation hotspot sites including codons 157, 158, 245, 248 and 273. We performed molecular modelling of BPDE-adducted TP53 duplex sequences to determine the degree of local distortion caused by adducts which could influence the ability of nucleotide excision repair. We show that BPDE adducted codon 157 has greater structural distortion than other TP53 G:C>T:A hotspot sites and that sequence context more distal to adjacent bases must influence local distortion. Using TP53 trinucleotide mutation signatures for lung cancer in smokers and non-smokers we further show that codons 157 and 273 have the highest mutation probability in smokers. Combining this information with adduct structural data we predict that G:C>T:A mutations at codon 157 in lung tumours of smokers are predominantly caused by BPDE. Our results provide insight into how different DNA sequence contexts show variability in DNA distortion at mutagen adduct sites that could compromise DNA repair at well characterized cancer related mutation hotspots. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. DNA2—An Important Player in DNA Damage Response or Just Another DNA Maintenance Protein?

    Directory of Open Access Journals (Sweden)

    Elzbieta Pawłowska

    2017-07-01

    Full Text Available The human DNA2 (DNA replication helicase/nuclease 2 protein is expressed in both the nucleus and mitochondria, where it displays ATPase-dependent nuclease and helicase activities. DNA2 plays an important role in the removing of long flaps in DNA replication and long-patch base excision repair (LP-BER, interacting with the replication protein A (RPA and the flap endonuclease 1 (FEN1. DNA2 can promote the restart of arrested replication fork along with Werner syndrome ATP-dependent helicase (WRN and Bloom syndrome protein (BLM. In mitochondria, DNA2 can facilitate primer removal during strand-displacement replication. DNA2 is involved in DNA double strand (DSB repair, in which it is complexed with BLM, RPA and MRN for DNA strand resection required for homologous recombination repair. DNA2 can be a major protein involved in the repair of complex DNA damage containing a DSB and a 5′ adduct resulting from a chemical group bound to DNA 5′ ends, created by ionizing radiation and several anticancer drugs, including etoposide, mitoxantrone and some anthracyclines. The role of DNA2 in telomere end maintenance and cell cycle regulation suggests its more general role in keeping genomic stability, which is impaired in cancer. Therefore DNA2 can be an attractive target in cancer therapy. This is supported by enhanced expression of DNA2 in many cancer cell lines with oncogene activation and premalignant cells. Therefore, DNA2 can be considered as a potential marker, useful in cancer therapy. DNA2, along with PARP1 inhibition, may be considered as a potential target for inducing synthetic lethality, a concept of killing tumor cells by targeting two essential genes.

  11. Ku80 interaction with apurinic/apyrimidinic sites depends on the structure of DNA ends

    Directory of Open Access Journals (Sweden)

    Kosova A. A.

    2014-01-01

    Full Text Available Aim. The identification of a protein from human cell extract which specifically interacts with the apurinic/apyrimidinic (AP site in the partial DNA duplex containing 5'and 3'-dangling ends (DDE-AP DNA and mimicking clustered DNA damage. Methods. The Schiff base-dependent cross-linking of a protein to AP DNA (borohydride trapping, MALDI-TOF-MS, chromatography, and gel electrophoresis. Results. A human cell extract protein which forms a major covalent adduct with the AP DNA duplex with dangling ends was identified as the Ku80 subunit of Ku antigen by peptide mass mapping based on MALDI-TOF-MS data. The Ku antigen purified from the HeLa cell extract was shown to form the covalent adducts with the same mobility as observed in cell extracts. Conclusions. The Ku80 subunit of Ku antigen can specifically interact with AP DNA forming the Schiff base-mediated adducts which electrophoretic mobility depends on the structure of DNA ends. The difference in electrophoretic mobility can be caused by the cross-linking of AP DNA to distinct target amino acids that appears to reflect unequal positioning of AP DNAs in the complex with Ku antigen.

  12. ANTIMONY HALIDES AND HgX2 (X = Cl, Br AMINE ADDUCTS: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    NDONGO GUEYE

    2013-12-01

    Full Text Available Eight new SbF3, SbCl5 and HgX2 (X = Cl, Br amine adducts have been synthesized and their infrared study carried out. Discrete structures have been suggested on the basis of elemental analysis and infrared data, the coordination number of antimony varying from five to nine, while the environment around Hg is tetrahedral.

  13. Determination of isocyanate specific albumin-adducts in workers exposed to toluene diisocyanates.

    Science.gov (United States)

    Sabbioni, Gabriele; Gu, Qi; Vanimireddy, Lakshiminiranjan Reddy

    2012-03-01

    Toluene diisocyanates (2,4-TDI and 2,6-TDI) are important intermediates in the chemical industry. Among the main damages after low levels of TDI exposure are lung sensitization and asthma. It is therefore necessary to have sensitive and specific methods to monitor isocyanate exposure of workers. Urinary metabolites or protein adducts have been used as biomarkers in workers exposed to TDI. However, with these methods it was not possible to determine if the biomarkers result from exposure to TDI or to the corresponding toluene diamines (TDA). This work presents a new procedure for the determination of isocyanate-specific albumin adducts. Isotope dilution mass spectrometry was used to measure the adducts in albumin present in workers exposed to TDI. 2,4-TDI and 2,6-TDI formed adducts with lysine: N(ϵ)-[({3-amino-4-methylphenyl}amino)carbonyl]-lysine, N(ϵ)-[({5-amino-2-methylphenyl}amino)carbonyl]-lysine, and N(ϵ)- [({3-amino-2-methylphenyl}amino)carbonyl]-lysine. In future studies, this new method can be applied to measure TDI-exposures in workers.

  14. Eccentric hip adduction and abduction strength in elite soccer players and matched controls

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Couppé, C; Petersen, J

    2011-01-01

    Eccentric hip adduction and abduction strength plays an important role in the treatment and prevention of groin injuries in soccer players. Lower extremity strength deficits of less than 10% on the injured side, compared to the uninjured side, have been suggested as the clinical milestone before...

  15. Laryngeal muscle activity and vocal fold adduction during chest, chestmix, headmix, and head registers in females.

    Science.gov (United States)

    Kochis-Jennings, Karen Ann; Finnegan, Eileen M; Hoffman, Henry T; Jaiswal, Sanyukta

    2012-03-01

    Commercial singers produce chestmix register by maintaining or increasing adduction of the vocal processes (VPs) and by engaging the thyroarytenoid (TA) muscle to a greater degree than they would to produce head register. Prospective cohort study. Simultaneous recordings of TA and cricothyroid (CT) muscle activity, videonasendoscopy, and audio were obtained from seven female singers during production of a variety of midrange pitches in chest, chestmix, headmix, and head registers. Fast Fourier transforms were performed to measure the energy in the fundamental frequency and in mid and upper frequency harmonics to determine if the productions that were judged as perceptually distinct registers also showed distinctive acoustic characteristics. Then, measures of TA and CT muscle activity and vocal fold adduction ratings were obtained to determine how these varied as a function of pitch and register. Spectral tilt increased as subjects shifted from chest to chestmix to headmix and finally into head register. For same pitch phonation, subjects increased TA muscle activity and vocal fold adduction as they shifted register from head to headmix to chestmix to chest, particularly during production of higher frequencies. CT activity appeared to be more related to pitch rather than register control. Nonclassically trained singers were able to produce pitches at the high end of the midrange in chestmix register by increasing TA muscle activity and adduction of the VPs. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  16. SYNTHESIS AND INFRARED STUDY OF SOME NEW IODATO ADDUCTS AND DERIVATIVES

    Directory of Open Access Journals (Sweden)

    HASSAN ALLOUCH

    2014-05-01

    Full Text Available Three iodato adducts and one derivative have been synthesized and studied by infrared data. The suggested structures are discrete, the iodate behaving as a mono- or bidentate ligand, or an infinite chain with bridging iodate, the environment around the tin centre being trigonal bipyramidal, tetrahedral or octahedral.

  17. The effectiveness of voluntary modifications of gait pattern to reduce the knee adduction moment

    NARCIS (Netherlands)

    van den Noort, J.C.; Schaffers, I.; Snijders, J.; Harlaar, J.

    2013-01-01

    It has been suggested to use gait modifications in the retraining of patients with knee osteoarthritis (OA), in order to reduce the external knee adduction moment (KAdM). This study focused on the effect of walking speed, foot position and trunk sway, and on the 3D knee moments. Gait analyses of

  18. Effect of external electric field on Cyclodextrin-Alcohol adducts: A ...

    Indian Academy of Sciences (India)

    Effect of external electric fields on the interaction energy between cyclodextrin and alcohol was analyzed in the light of density functional theory (DFT) and density functional reactivity theory (DFRT). Stability of the cyclodextrin-alcohol adducts was measured in terms of DFT based reactivity descriptor, global hardness, ...

  19. Quantum Chemical Studies on Detail Mechanism of Nitrosylation of NAMI-A-HSA Adduct.

    Science.gov (United States)

    Das, Dharitri; Mondal, Paritosh

    2015-08-20

    Hydrolysis of NAMI-A in NAMI-A-HSA (HSA = human serum albumin) and nitrosylation of hydrolyzed NAMI-A-HSA adduct have been studied in detail using density functional theory method. It has been observed that the chloride exchange reaction with water in the NAMI-A-HSA adduct follows an interchange dissociative mechanism passing through an unstable heptacoordinated activated complex. The computed free energy of activation (ΔG) and rate constant (k) for the hydrolysis process in aqueous medium are observed to be 24.85 kcal mol(-1) and 3.81 × 10(-6) s(-1), respectively. Nitrosylation of hydrolyzed NAMI-A-HSA adduct with nitric oxide is found to be thermodynamically more favorable with the incorporation of solvent effect and provides a detailed understanding related to the antimetastatic activity of the NAMI-A drug. This investigation shows that nitric oxide coordinates linearly to NAMI-A-HSA adduct leading to the reduction of ruthenium(III) to more active ruthenium(II), with the reduction potential of -2.32 V. Negative relative solvation and relative binding free energies suggest that the hydrolysis and nitrosylation reactions are found to be thermodynamically favorable and faster. Our computed results provide a detailed thermodynamics and kinetics which may be highly beneficial for understanding antimetastatic activity as well as the nitric oxide scavenging ability of NAMI-A.

  20. 40 CFR 721.465 - Alkoxylated alkylpolyol acrylates, adduct with alkylamine (generic).

    Science.gov (United States)

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES... substances identified generically as alkoxylated alkylpolyol acrylates, adduct with alkylamine (PMNs P-98... provisions of subpart A of this part apply to this section except as modified by this paragraph. (1...

  1. Conformational, IR spectroscopic and electronic properties of conium alkaloids and their adducts with C60 fullerene

    Science.gov (United States)

    Zabolotnyi, M. A.; Prylutskyy, Yu I.; Poluyan, N. A.; Evstigneev, M. P.; Dovbeshko, G. I.

    2016-08-01

    Conformational, IR spectroscopic and electronic properties of the components of Conium alkaloids (Conium maculatum) in aqueous environment were determined by model calculations and experiment. With the help of FT-IR spectroscopy the possibility of formation of an adduct between γ-coniceine alkaloid and C60 fullerene was demonstrated, which is important for further application of conium analogues in biomedical purposes.

  2. Separation and characterization of oxidized isomeric lipid-peptide adducts by ion mobility mass spectrometry.

    Science.gov (United States)

    Milic, Ivana; Kipping, Marc; Hoffmann, Ralf; Fedorova, Maria

    2015-12-01

    Phospholipids are major components of cell membranes and lipoprotein complexes. They are prone to oxidation by endogenous and exogenous reactive oxygen species yielding a large variety of modified lipids including small aliphatic and phospholipid bound aldehydes and ketones. These carbonyls are strong electrophiles that can modify proteins and, thereby, alter their structures and functions triggering various pathophysiological conditions. The analysis of lipid-protein adducts by liquid chromatography-MS is challenged by their mixed chemical nature (polar peptide and hydrophobic lipid), low abundance in biological samples, and formation of multiple isomers. Thus, we investigated traveling wave ion mobility mass spectrometry (TWIMS) to analyze lipid-peptide adducts generated by incubating model peptides corresponding to the amphipathic β1 sheet sequence of apolipoprotein B-100 with 1-palmitoyl-2-(oxo-nonanoyl)-sn-glycerophosphatidylcholine (PONPC). The complex mixture of peptides, lipids, and peptide-lipid adducts was separated by TWIMS, which was especially important for the identification of two mono-PONPC-peptide isomers containing Schiff bases at different lysine residues. Moreover, TWIMS separated structural conformers of one peptide-lipid adduct possessing most likely different orientations of the hydrophobic sn-1 fatty acyl residue and head group of PONPC, relative to the peptide backbone. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Formation of a Hydroxymethylfurfural-Cysteine Adduct and Its Absorption and Cytotoxicity in Caco-2 Cells.

    Science.gov (United States)

    Zhao, Qianzhu; Zou, Yueyu; Huang, Caihuan; Lan, Ping; Zheng, Jie; Ou, Shiyi

    2017-11-15

    Adducts of 5-hydroxymethylfurfural (HMF)-amino acids are formed during food processing and digestion; the elimination capacity of in vitro intestinal digests of biscuits, instant noodles, and potato crisps for HMF is 652, 727, and 540 μg/g, respectively. However, the safety of these adducts is unknown. In this study, an HMF-cysteine adduct named 1-dicysteinethioacetal-5-hydroxymehtylfurfural (DCH), which was found to be produced in the gastrointestinal tract after HMF intake, was prepared to test its effect toward Caco-2 cells. Compared with HMF, the adduct displayed lower cytotoxicity against Caco-2 cells with an IC50 value of 31.26 mM versus 14.95 mM (HMF). The DCH did not induce cell apoptosis, whereas HMF significantly increased the apoptosis rate after incubation at concentrations of 16, 32, and 48 mM for 72 h. DCH showed an absorption rate considerably lower than that of HMF by Caco-2 cells. Lower absorption of DCH may result in lower toxicity compared with HMF against Caco-2 cells. Intracellular transformation of DCH has been observed.

  4. The regioselectivity of glutathione adduct formation with flavonoid quinone methides is pH-dependent

    NARCIS (Netherlands)

    Awad, H.M.; Boersma, M.G.; Boeren, S.; Vervoort, J.; Bladeren, van P.J.; Rietjens, I.M.C.M.

    2002-01-01

    In the present study, the formation of glutathionyl adducts from a series of 3',4'-dihydroxy flavonoid o-quinone/p-quinone methides was investigated with special emphasis on the regioselectivity of the glutathione addition as a function of pH. The flavonoid o-quinones were generated using

  5. New adduct of abietane-type diterpene from Salvia leriifolia Benth.

    Science.gov (United States)

    Hussain, Amjad; Adhikari, Achyut; Iqbal Choudhary, M; Ayatollahi, Syed Abdulmajid; Atta-Ur-Rahman

    2016-07-01

    A new adduct of abietane-type diterpene, salvialeriicone (1), was isolated from Salvia leriifolia Benth., along with a new chemical entity nor-abietane diterpene, 2-isopropyl-8,8-dimethyl-7,8-dihydrophenanthrene-1,4,5(6H)-trione (2). Their structures were determined using mass spectrometry, and 1D- and 2D-NMR spectroscopy.

  6. Acetonitrile adduct formation as a sensitive means for simple alcohol detection by LC-MS.

    Science.gov (United States)

    Bogseth, Roy; Edgcomb, Eric; Jones, Christopher M; Chess, Edward K; Hu, Peifeng

    2014-11-01

    Simple alcohols formed protonated acetonitrile adducts containing up to two acetonitrile molecules when analyzed by ESI or APCI in the presence of acetonitrile in the solvent. These acetonitrile adducts underwent dissociation to form a nitrilium ion, also referred to as the substitution ion. Diols and triols behaved differently. In ESI, they formed only one acetonitrile adduct containing one acetonitrile. The S ion was not observed in ESI and was only weakly observed from the dissociation of the (M + ACN + H)(+) ion. On the other hand, the S ion was abundantly formed from the diols in APCI. This formation of acetonitrile adducts and substitution ion from simple alcohols/diols offers an opportunity to detect simple alcohols/diols sensitively by LC-MS interfaced by ESI or APCI. The utility of this chemistry was demonstrated in a method developed for the quantification of cyclohexanol in rat plasma by monitoring the CID-induced fragmentation from the S ion to a fragment ion.

  7. (S)-Garner aldehyde derived Baylis-Hillman adduct: A potential ...

    Indian Academy of Sciences (India)

    Abstract. A short, facile and efficient synthesis of D-lyxo-phytosphingosine analogue has been achieved. The key steps involved are the Baylis-Hillman reaction of (S)-Garner aldehyde with methyl acrylate to obtain the corresponding adduct as the potential substrate, to which was added decylmagnesium bromide to.

  8. The mycotoxin patulin reacts with DNA bases with and without previous conjugation to GSH: implication for related α,β-unsaturated carbonyl compounds?

    Science.gov (United States)

    Pfenning, Carolin; Esch, Harald L; Fliege, Ralph; Lehmann, Leane

    2016-02-01

    The α,β-unsaturated carbonyl group is recognized as alert for mutagenicity, attributed to (1) its direct reaction with DNA, counteractable by glutathione (GSH), and (2) oxidative stress caused indirectly by GSH depletion. Accordingly, the α,β,γ,δ-unsaturated lactone patulin (PAT), a mycotoxin detected in fruits and products derived thereof, is known to induce gene, chromosome, and genome mutations in vitro, its mutagenicity correlating inversely with intracellular GSH levels. Thus, the reactivity of PAT against DNA bases and nucleosides in the absence and presence of GSH and glutathione S-transferases (GSTs) was investigated under cell-free conditions using HPLC mass spectrometry techniques for identification of reaction products. Adduct formation with all four nucleobases as well as with purine base nucleosides occurred even in the presence of GSH, revealing several adducts of PAT, mono- and disubstituted with nucleobases/nucleosides as well as novel GSH-PAT adducts. In addition, novel mixed GSH-PAT-nucleobase adducts were observed. These adducts exhibited a ketohexanoic acid-type structure of the PAT molecule, C6 substituted with GSH and linking C1 of PAT with nitrogens of nucleobases/nucleosides via an amide bond. Formation of GSH-PAT-adenine adducts was not prevented by GSTs, and excess of GSH needed to reduce their formation was higher than for PAT-adenine adducts. The formation of mixed GSH-DNA base adducts has not been described for PAT or any other α,β-unsaturated carbonyl before, although the reaction mechanism seems to be applicable to a variety of α,β-unsaturated carbonyls occurring in food and in the environment.

  9. Vaccinia virus encodes a polypeptide with DNA ligase activity.

    Science.gov (United States)

    Kerr, S M; Smith, G L

    1989-11-25

    Vaccinia virus gene SalF 15R potentially encodes a polypeptide of 63 kD which shares 30% amino acid identity with S. pombe and S. cerevisiae DNA ligases. DNA ligase proteins can be identified by incubation with alpha-(32P)ATP, resulting in the formation of a covalent DNA ligase-AMP adduct, an intermediate in the enzyme reaction. A novel radio-labelled polypeptide of approximately 61 kD appears in extracts from vaccinia virus infected cells after incubation with alpha-(32P)ATP. This protein is present throughout infection and is a DNA ligase as the radioactivity is discharged in the presence of either DNA substrate or pyrophosphate. DNA ligase assays show an increase in enzyme activity in cell extracts after vaccinia virus infection. A rabbit antiserum, raised against a bacterial fusion protein of beta-galactosidase and a portion of SalF 15R, immune-precipitates polypeptides of 61 and 54 kD from extracts of vaccinia virus-infected cells. This antiserum also immune-precipitates the novel DNA ligase-AMP adduct, thus proving that the observed DNA ligase is encoded by SalF 15R.

  10. Differences in micronucleus frequency and acrylamide adduct levels with hemoglobin between vegetarians and non-vegetarians.

    Science.gov (United States)

    Kotova, Natalia; Frostne, Cecilia; Abramsson-Zetterberg, Lilianne; Tareke, Eden; Bergman, Rolf; Haghdoost, Siamak; Paulsson, Birgit; Törnqvist, Margareta; Segerbäck, Dan; Jenssen, Dag; Grawé, Jan

    2015-10-01

    Nutrients and food constituents can prevent or contribute to genotoxicity. In this study, the possible influence of a vegetarian/non-vegetarian diet on genotoxic effects was investigated in 58 non-smoking healthy vegetarians (V) and non-vegetarians (NV), age 21-37 years from the Stockholm area in Sweden. Physical activity and dietary habits were similar in both groups, with the exception of the intake of meat and fish. Using flow cytometry, we determined the formation of micronuclei (MN) in transferrin-positive immature peripheral blood reticulocytes (Trf-Ret) (Total: n = 53; V: n = 27; NV: n = 26). Dietary exposure to acrylamide was measured through hemoglobin (Hb) adducts in peripheral erythrocytes (Total: n = 53; V: n = 29; NV: n = 24). Hb adducts of both acrylamide and its genotoxic metabolite glycidamide were monitored as a measure of the corresponding in vivo doses. Our data demonstrated that compared with the non-vegetarians, the vegetarians exhibited lower frequencies of MN (fMN) in the Trf-Ret (p vegetarians and non-vegetarians. Furthermore, there were no significant relationships between the adduct levels and fMN in the individuals. The ratio of the Hb adduct levels from glycidamide and acrylamide, however, showed a significant difference (p vegetarian diet might be beneficial in lowering genomic instability in healthy individuals. The measured Hb adduct levels indicate that the total intake of acrylamide does not differ between the two studied groups and does not contribute to the observed difference in fMN, although an influence of the diet on the metabolic rates of acrylamide was indicated. In addition, the observed significant difference in the background fMN in the two groups demonstrated that the MN analysis method has a sensitivity applicable to the biomonitoring of human lifestyle factors.

  11. Comparison of Bile Acids and Acetaminophen Protein Adducts in Children and Adolescents with Acetaminophen Toxicity.

    Directory of Open Access Journals (Sweden)

    Laura James

    Full Text Available Metabolomics approaches have enabled the study of new mechanisms of liver injury in experimental models of drug toxicity. Disruption of bile acid homeostasis is a known mechanism of drug induced liver injury. The relationship of individual bile acids to indicators of oxidative drug metabolism (acetaminophen protein adducts and liver injury was examined in children with acetaminophen overdose, hospitalized children with low dose exposure to acetaminophen, and children with no recent exposure to acetaminophen. Nine bile acids were quantified through targeted metabolomic analysis in the serum samples of the three groups. Bile acids were compared to serum levels of acetaminophen protein adducts and alanine aminotransferase. Glycodeoxycholic acid, taurodeoxycholic acid, and glycochenodeoxycholic acid were significantly increased in children with acetaminophen overdose compared to healthy controls. Among patients with acetaminophen overdose, bile acids were higher in subjects with acetaminophen protein adduct values > 1.0 nmol/mL and modest correlations were noted for three bile acids and acetaminophen protein adducts as follows: taurodeoxycholic acid (R=0.604; p<0.001, glycodeoxycholic acid (R=0.581; p<0.001, and glycochenodeoxycholic acid (R=0.571; p<0.001. Variability in bile acids was greater among hospitalized children receiving low doses of acetaminophen than in healthy children with no recent acetaminophen exposure. Compared to bile acids, acetaminophen protein adducts more accurately discriminated among children with acetaminophen overdose, children with low dose exposure to acetaminophen, and healthy control subjects. In children with acetaminophen overdose, elevations of conjugated bile acids were associated with specific indicators of acetaminophen metabolism and non-specific indicators of liver injury.

  12. Immunoassay of haemoglobin-acrylonitrile adduct in rat as a biomarker of exposure.

    Science.gov (United States)

    L Wong Yu Ting Zheng Junyu Li Carlo H Tamburro Frederick W Benz, J

    1998-01-01

    Acrylonitrile (AN) is a rat carcinogen. Human exposure may come from chemical industries and smoking. A haemoglobin adduct of acrylonitrile (Hb-AN) has been used as a biomarker of exposure by means of gas chromatography-mass spectrometry (GC-MS) analysis. We have developed specific monoclonal antibodies (Mab) to human Hb-AN and wish to report evaluation of an immunoassay in rats using an Mab that cross-reacts with rat Hb-AN. A dose response study of LD 0, 10, 50, and 90 in Sprague-Dawley rats was undertaken, with each rat receiving \\[2,3-14C]AN at 50 Ci kg-1 sc, and Hb from an aliquot of blood was taken for covalent binding analysis by liquid scintillation spectrometry and fluorescence ELISA. The dose responses of rats at 0.25, 0.5, 1.0, and 2.0 h after AN doses of 20, 50, 80, 115 mg kg-1 were compared by both methods with Hb and globin samples. Regression analysis showed a linear relationship between immunoassay and 14C-AN binding. This indicates that an antigenic form of Hb-AN may be used as a surrogate of Hb-AN adduct. The sensitivity of ELISA was tested in rats exposed for 1 h to sub-toxic doses of AN (10-1.1 mg kg-1). Quantification of Hb-AN by immunoassay was achieved by calibration with a synthetic adduct HbAN4h, a reference adduct prepared by treating rat Hb with excess AN for 4 h. ELISA and GC-MS analysis of N-terminal valine-AN in the Hb-AN adduct were compared and similar detection levels were found. This rat study appears to have validated the new immunoassay method for biomonitoring of AN exposure.

  13. Hybrid nano-composites made of ss-DNA/wrapped carbon nanotubes and titania.

    Science.gov (United States)

    Romio, Martina; Mesa, Camillo La

    2017-04-01

    Multi-walled carbon nanotubes, MWCNTs, are stabilized thanks to the surface wrapping of single-strand DNA, ss-DNA; the resulting adducts are kinetically and thermodynamically stable Such entities build up nano-hybrids with titania, TiO2, nano-particles, in presence of surfactant as an adjuvant. The conditions leading to TiO2 adsorption onto ss-DNA/CNTs were investigated, by optimizing the concentration of adducts, nano-particles (NPs), and of the cationic surfactant (CTAB). Controlling the working conditions makes possible to get homogeneously organized hybrids. Characterization by DLS, electro-phoretic mobility, SEM and AFM clarified the surfactant-assisted association modes between adducts and CTAB-functionalized TiO2. Nano-particles' clustering onto DNA-wrapped adducts gives hybrids trough electrostatic interactions. Surface coverage by TiO2 is significant and homogeneous. It is expected that the reported hybrids can be useful for applications in heterogeneous catalysis. Copyright © 2016. Published by Elsevier B.V.

  14. DNA repair polymorphisms and cancer risk in non-smokers in a cohort study.

    NARCIS (Netherlands)

    Matullo, G; Dunning, A M; Guarrera, S; Baynes, C; Polidoro, S; Garte, S; Autrup, H; Malaveille, C; Peluso, M; Airoldi, L; Veglia, F; Gormally, E; Hoek, G; Krzyzanowski, M; Overvad, K; Raaschou-Nielsen, O; Clavel-Chapelon, F; Linseisen, J; Boeing, H; Trichopoulou, A; Palli, D; Krogh, V; Tumino, R; Panico, S; Bueno-De-Mesquita, H Bas; Peeters, Petra H M; Lund, E; Pera, G; Martinez, C; Dorronsoro, M; Barricarte, A; Tormo, M J; Quiros, J R; Day, N E; Key, T J; Saracci, R; Kaaks, R; Riboli, E; Vineis, P

    2006-01-01

    Environmental carcinogens contained in air pollution, such as polycyclic aromatic hydrocarbons, aromatic amines or N-nitroso compounds, predominantly form DNA adducts but can also generate interstrand cross-links and reactive oxygen species. If unrepaired, such lesions increase the risk of somatic

  15. Benzoyl peroxide-induced damage to DNA and its components

    DEFF Research Database (Denmark)

    Hazlewood, C; Davies, Michael Jonathan

    1996-01-01

    , sugars, nucleosides, nucleotides, RNA, and DNA have been examined and the intermediate species have been identified in many cases. Comparison of these data with those obtained with Ph. alone has allowed the reactions of PhCO2. and Ph. to be distinguished. Evidence has been obtained which is consistent...... with both the addition of these radicals to the C5-C6 double bond of the pyrimidines to give adduct species, and hydrogen abstraction from the sugar rings. The former process is the major reaction for nucleosides and nucleotides. Studies with RNA and DNA also provide strong evidence for the formation...... of base adducts, though the exact identity of the species detected in these cases could not be determined due to the complexity of the spectra. Hydrogen abstraction at the sugar-phosphate backbone is also believed to occur with these substrates as strand breakage is observed; the extent of the latter...

  16. Coordination of sodium cation to an oxygen function and olefinic double bond to form molecular adduct ion in fast atom bombardment mass spectrometry.

    Science.gov (United States)

    Morisaki, Naoko; Kobayashi, Hisayoshi; Yamamura, Yumiko; Morisaki, Masuo; Nagasawa, Kazuo; Hashimoto, Yuichi

    2002-07-01

    Steroidal allylic alcohols formed Na+ adduct ion peaks [M+Na]+ by the addition of NaCl in FAB mass spectrometry. A comparison of the intensities of the adduct ion peaks of allylic alcohols with those of the corresponding saturated alcohols and olefin suggested that the olefinic double bond and the proximal hydroxyl group had coordinated to Na+. The adduct ion was stable and did not undergo dehydroxylation. We suggest that the Na+ adduction will be useful for the molecular weight determination of allylic alcohols which are susceptible to dehydroxylation under FAB mass spectrometric conditions. Na+ adduct ions of alpha,beta-unsaturated carbonyl compounds were also investigated.

  17. Differences in hemoglobin adduct levels of acrylamide in the general population with respect to dietary intake, smoking habits and gender.

    Science.gov (United States)

    Hagmar, Lars; Wirfält, Elisabet; Paulsson, Birgit; Törnqvist, Margareta

    2005-02-07

    The variation in dietary exposure to acrylamide (AA) has been studied through measurement of hemoglobin adduct levels from AA, as a measurement of internal dose, in a sample from the blood bank of the Malmö Diet and Cancer Cohort (n=28,098). The blood donors are well characterised with regard to their food habits, and 142 individuals were selected to obtain highest possible variation in the adduct levels from AA (none, random or high intake of coffee, fried potato, crisp bread and snacks, food items estimated to have high levels of AA). Among 70 non-smokers the AA-adduct levels varied by a factor of 5, and ranged between 0.02 and 0.1 nmol/g, with considerable overlap in AA-adduct levels between the different dietary groups. There was a significant difference between men with high dietary exposure to AA compared to men with low dietary exposure (P=0.04). No such difference was found for women. As expected a higher level (range: 0.03-0.43 nmol/g) of the AA-adduct, due to AA in tobacco smoke, was found in smokers. Smoking women with high dietary exposure to AA had significantly higher AA-adduct levels compared to smoking women with low dietary exposure (P=0.01). No such significant difference was found in smoking men. The median hemoglobin (Hb) adduct level in the randomly selected group of non-smokers was compatible with earlier studies (0.031 nmol/g). The variation in the average internal dose, measured as Hb adducts, was somewhat smaller than estimated for daily intake by food consumption questionnaires in other studies. Thus, the observed relatively narrow inter-individual variation in AA-adduct levels means that estimates of individual dietary AA intake have to be very precise if they should be useful in future cancer epidemiology.

  18. Metformin inhibits 7,12-dimethylbenz[a]anthracene-induced breast carcinogenesis and adduct formation in human breast cells by inhibiting the cytochrome P4501A1/aryl hydrocarbon receptor signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Maayah, Zaid H. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Ghebeh, Hazem [Stem Cell & Tissue Re-Engineering, King Faisal Specialist Hospital and Research Center, Riyadh 11211 (Saudi Arabia); Alhaider, Abdulqader A. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Camel Biomedical Research Unit, College of Pharmacy and Medicine, King Saud University, Riyadh 11451 (Saudi Arabia); El-Kadi, Ayman O.S. [Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton (Canada); Soshilov, Anatoly A.; Denison, Michael S. [Department of Environmental Toxicology, University of California at Davis, Davis, CA 95616 (United States); Ansari, Mushtaq Ahmad [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Korashy, Hesham M., E-mail: hkorashy@ksu.edu.sa [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia)

    2015-04-15

    Recent studies have established that metformin (MET), an oral anti-diabetic drug, possesses antioxidant activity and is effective against different types of cancer in several carcinogen-induced animal models and cell lines. However, whether MET can protect against breast cancer has not been reported before. Therefore, the overall objectives of the present study are to elucidate the potential chemopreventive effect of MET in non-cancerous human breast MCF10A cells and explore the underlying mechanism involved, specifically the role of cytochrome P4501A1 (CYP1A1)/aryl hydrocarbon receptor (AhR) pathway. Transformation of the MCF10A cells into initiated breast cancer cells with DNA adduct formation was conducted using 7,12-dimethylbenz[a]anthracene (DMBA), an AhR ligand. The chemopreventive effect of MET against DMBA-induced breast carcinogenesis was evidenced by the capability of MET to restore the induction of the mRNA levels of basic excision repair genes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endonuclease1 (APE1), and the level of 8-hydroxy-2-deoxyguanosine (8-OHdG). Interestingly, the inhibition of DMBA-induced DNA adduct formation was associated with proportional decrease in CYP1A1 and in NAD(P)H:quinone oxidoreductase 1 (NQO1) gene expression. Mechanistically, the involvements of AhR and nuclear factor erythroid 2-related factor-2 (Nrf2) in the MET-mediated inhibition of DMBA-induced CYP1A1 and NQO1 gene expression were evidenced by the ability of MET to inhibit DMBA-induced xenobiotic responsive element and antioxidant responsive element luciferase reporter gene expression which suggests an AhR- and Nrf2-dependent transcriptional control. However, the inability of MET to bind to AhR suggests that MET is not an AhR ligand. In conclusion, the present work shows a strong evidence that MET inhibits the DMBA-mediated carcinogenicity and adduct formation by inhibiting the expression of CYP1A1 through an AhR ligand-independent mechanism

  19. Temozolomide chemoresistance heterogeneity in melanoma with different treatment regimens: DNA damage accumulation contribution.

    Science.gov (United States)

    Boeckmann, Lars; Nickel, Ann-Christin; Kuschal, Christiane; Schaefer, Annika; Thoms, Kai-Martin; Schön, Michael P; Thomale, Jürgen; Emmert, Steffen

    2011-06-01

    The efficacy of temozolomide in melanoma treatment is low (response rate DNA methyltransferase (MGMT) and mismatch repair. We identified melanoma cell lines with different sensitivities to single versus prolonged clinical dosing regimens of temozolomide treatment and assessed a variety of potential resistance mechanisms using this model. We measured mRNA expression and promoter methylation of MGMT and essential mismatch repair genes (MLH1, MSH2). Cell cycle distribution, apoptosis/necrosis induction, O-methylguanine-adduct formation, and ABCB1 gene expression were assessed. We found that three cell lines, MelA, MelB, and MelC, were more sensitive to a single dose regimen than to a prolonged regimen, which would be expected to exhibit higher cytotoxicity. KAII and LIBR cell sensitivity was higher with regard to the prolonged treatment regimen, as expected. Only MelC expressed MGMT. Gene expression correlated well with promoter methylation. Temozolomide exposure did not alter mRNA expression. Different sensitivities to temozolomide were caused neither by delayed apoptosis induction due to early cell cycle arrest nor by O-methylguanine-adduct formation or efflux transporter expression. MelC was the most resistant cell line with rapid elimination of O-methylguanine adducts. This was in good agreement with its MGMT expression. The sensitive cell lines KAII and LIBR accumulated O-methylguanine adducts after a second treatment cycle with temozolomide in contrast with the other three cell lines. We conclude that MGMT expression and DNA adduct accumulation are relevant factors in temozolomide chemosensitivity. Considering individualized temozolomide treatment regimens either by quantification of DNA adducts or by chemosensitivity testing seems worthwhile clinically.

  20. Trapeziometacarpal Arthritis: A Prospective Clinical Evaluation of the Thumb Adduction and Extension Provocative Tests.

    Science.gov (United States)

    Gelberman, Richard H; Boone, Sean; Osei, Daniel A; Cherney, Steven; Calfee, Ryan P

    2015-07-01

    To determine the diagnostic performance (ie, sensitivity, specificity, interrater reliability) of the thumb metacarpal adduction and extension tests against traditional examination maneuvers for trapeziometacarpal (TMC) arthritis. This cross-sectional study recruited 129 patients from 2 outpatient offices at a tertiary institution. All patients had radiographic wrist examinations and completed a standardized physical examination consisting of the thumb adduction and extension tests as well as standard examination maneuvers for radial wrist and thumb pain. The physical examinations were performed by 1 of 2 attending physicians and an independent examiner. Patients were recruited for 3 diagnostic groups: TMC arthritis, radial wrist or hand pain, and nonradial wrist pain controls. Statistical analysis calculated the sensitivity, specificity, and interrater reliability of each physical examination maneuver for detecting TMC arthritis. The thumb adduction maneuver was found to have a sensitivity of 0.94 (confidence interval [CI], 0.82-0.98) and a specificity of 0.93 (CI, 0.86-0.97). The thumb extension maneuver had a sensitivity of 0.94 (CI, 0.82-0.98) and a specificity of 0.95 (CI, 0.87-0.98). The interrater reliability was excellent for both the adduction (κ = 0.79) and the extension tests (κ = 0.84). The grind test had a sensitivity of 0.44 (CI, 0.30-0.59), a specificity of 0.92 (CI, 0.84-0.97), and poor interrater reliability (0.31). Point tenderness at the TMC joint had a sensitivity of 0.94 (CI, 0.82-0.98), a specificity of 0.81 (CI, 0.71-0.88) and fair interrater reliability (κ = 0.63). The adduction and extension tests each proved to be more sensitive than the grind test for the detection of TMC arthritis. Further, these provocative tests were more specific for basal joint arthrosis than was the elicitation of point tenderness at the joint. The metacarpal adduction and extension maneuvers demonstrated excellent utility as screening tests for the

  1. Vitamin C for DNA damage prevention

    Energy Technology Data Exchange (ETDEWEB)

    Sram, Radim J., E-mail: sram@biomed.cas.cz [Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague 4 (Czech Republic); Binkova, Blanka; Rossner, Pavel [Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague 4 (Czech Republic)

    2012-05-01

    The ability of vitamin C to affect genetic damage was reviewed in human studies that used molecular epidemiology methods, including analysis of DNA adducts, DNA strand breakage (using the Comet assay), oxidative damage measured as levels of 8-oxo-7,8-dihydroxy-2 Prime -deoxyguanosine (8-oxodG), cytogenetic analysis of chromosomal aberrations and micronuclei, and the induction of DNA repair proteins. The protective effect of vitamin C was observed at plasma levels > 50 {mu}mol/l. Vitamin C supplementation decreased the frequency of chromosomal aberrations in groups with insufficient dietary intake who were occupationally exposed to mutagens, and also decreased the sensitivity to mutagens as assessed using the bleomycin assay. High vitamin C levels in plasma decreased the frequency of genomic translocations in groups exposed to ionizing radiation or c-PAHs in polluted air. The frequency of micronuclei was decreased by vitamin C supplementation in smokers challenged with {gamma}-irradiation, and higher vitamin C levels in plasma counteracted the damage induced by air pollution. The prevalence of DNA adducts inversely correlated with vitamin C levels in groups environmentally exposed to high concentrations of c-PAHs. Increased vitamin C levels decreased DNA strand breakage induced by air pollution. Oxidative damage (8-oxodG levels) was decreased by vitamin C supplementation in groups with plasma levels > 50 {mu}mol/l exposed to PM2.5 and c-PAHs. Modulation of DNA repair by vitamin C supplementation was observed both in poorly nourished subjects and in groups with vitamin C plasma levels > 50 {mu}mol/l exposed to higher concentrations of c-PAHs. It is possible that the impact of vitamin C on DNA damage depends both on background values of vitamin C in the individual as well as on the level of exposure to xenobiotics or oxidative stress.

  2. Replication of N[superscript 2],3-Ethenoguanine by DNA Polymerases

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Linlin; Christov, Plamen P.; Kozekov, Ivan D.; Pence, Matthew G.; Pallan, Pradeep S.; Rizzo, Carmelo J.; Egli, Martin; Guengerich, F. Peter (Vanderbilt)

    2014-10-02

    The unstable DNA adduct N2,3-ethenoguanine, a product of both exposure to the carcinogen vinyl chloride and of oxidative stress, was built into an oligonucleotide, using an isostere strategy to stabilize the glycosidic bond. This modification was then used to examine the cause of mutations by DNA polymerases, in terms of both the biochemistry of the lesion and a structure of the lesion within a polymerase.

  3. Conformational analysis of site-specific DNA cross-links of cisplatin-distamycin conjugates.

    Science.gov (United States)

    Kostrhunova, H; Brabec, V

    2000-10-17

    The requirement for novel platinum antitumor drugs led to the concept of synthesis of novel platinum drugs based on targeting cisplatin to various carrier molecules. We have shown [Loskotova, H., and Brabec, V. (1999) Eur. J. Biochem. 266, 392-402] that attachment of DNA minor-groove-binder distamycin to cisplatin changes several features of DNA-binding mode of the parent platinum drug. Major differences comprise different conformational changes in DNA and a considerably higher interstrand cross-linking efficiency. The studies of the present work have been directed to the analysis of oligodeoxyribonucleotide duplexes containing single, site-specific adducts of platinum-distamycin conjugates. These uniquely modified duplexes were analyzed by Maxam-Gilbert footprinting, phase-sensitive gel electrophoresis bending assay and chemical probes of DNA conformation. The results have indicated that the attachment of distamycin to cisplatin mainly affects the sites involved in the interstrand cross-links so that these adducts are preferentially formed between complementary guanine and cytosine residues. This interstrand cross-link bends the helix axis by approximately 35 degrees toward minor groove, unwinds DNA by approximately 95 degrees and distorts DNA symmetrically around the adduct. In addition, CD spectra of restriction fragments modified by the cisplatin-distamycin conjugates have demonstrated that distamycin moiety in the interstrand cross-links of these compounds interacts with DNA. This interaction facilitates the formation of these adducts. Hence, the structural impact of the specific interstrand cross-link detected in this study deserves attention when biological behavior of cisplatin derivatives targeted by oligopeptide DNA minor-groove-binders is evaluated.

  4. A microdosing approach for characterizing formation and repair of carboplatin–DNA monoadducts and chemoresistance

    Science.gov (United States)

    Henderson, Paul T.; Li, Tao; He, Miaoling; Zhang, Hongyong; Malfatti, Michael; Gandara, David; Grimminger, Peter P.; Danenberg, Kathleen D.; Beckett, Laurel; de Vere White, Ralph W.; Turteltaub, Kenneth W.; Pan, Chong-Xian

    2011-01-01

    Formation and repair of platinum (Pt)-induced DNA adducts is a critical step in Pt drug-mediated cytotoxicity. Measurement of Pt–DNA adduct kinetics in tumors may be useful for better understanding chemoresistance and therapeutic response. However, this concept has yet to be rigorously tested because of technical challenges in measuring the adducts at low concentrations and consistent access to sufficient tumor biopsy material. Ultrasensitive accelerator mass spectrometry was used to detect [14C]carboplatin–DNA monoadducts at the attomole level, which are the precursors to Pt–DNA crosslink formation, in six cancer cell lines as a proof-of-concept. The most resistant cells had the lowest monoadduct levels at all time points over 24 hr. [14C]Carboplatin “microdoses" (1/100th the pharmacologically effective concentration) had nearly identical adduct formation and repair kinetics compared to therapeutically relevant doses, suggesting that the microdosing approach can potentially be used to determine the pharmacological effects of therapeutic treatment. Some of the possible chemoresistance mechanisms were also studied, such as drug uptake/efflux, intracellular inactivation and DNA repair in selected cell lines. Intracellular inactivation and efficient DNA repair each contributed significantly to the suppression of DNA monoadduct formation in the most resistant cell line compared to the most sensitive cell line studied (p carboplatin monoadduct concentrations over 24 hr that likely contributed to chemoresistance. The data support the utility of carboplatin microdosing as a translatable approach for defining carboplatin–DNA monoadduct formation and repair, possibly by NER, which may be useful for characterizing chemoresistance in vivo. PMID:21128223

  5. SYNTHESIS AND INFRARED STUDY OF SOME NEW MOLYBDATO AND HYDROGENOMOLYBDATO ADDUCTS AND COMPLEXES OF COBALT, ZINC, ANTIMONY AND CADMIUM CHLORIDES

    Directory of Open Access Journals (Sweden)

    SERIGNE FALLOU POUYE

    2014-01-01

    Full Text Available Five new molybdato (four and hydrogenomolybdato (one adducts and complexes have been synthesized and studied by infrared spectroscopy. The suggested structures are all discrete, the molybdate anion behaving as a trichelating, a monochelating, a bridging, a tetrachelating and a bichelating ligand. The environment around Zn, Co, Cd is tetrahedral or trigonal bipyramidal also for Zn - while being octahedral for Sb. The Cd pentanuclear adduct has a two metallic components structure, a tetranuclear anionic one with a tetrachelating molybdate, the second being a neutral dehydrated adduct component. The suggested structure for the hydrogenomolybdato adduct is discrete, the hydrogenomolybdate being present as a hydrogen bonded dimer behaves as a bridging bidentate ligand. The water molecules can be considered as a coordinating ligand or lattice. When secondary interactions through hydrogen bonds involving the water molecules are considered supramolecular architectures are obtained.

  6. Carbonyl-Phenol Adducts: An Alternative Sink for Reactive and Potentially Toxic Lipid Oxidation Products.

    Science.gov (United States)

    Zamora, Rosario; Hidalgo, Francisco J

    2018-02-14

    Different from the well-characterized function of phenolics as antioxidants, their function as lipid-derived carbonyl scavengers is mostly unknown. However, phenolics react with lipid-derived carbonyls as a function of the nucleophilicity of their reactive groups and the electronic effects and steric hindrances present in the reactive carbonyls. Furthermore, the reaction produces a wide variety of carbonyl-phenol adducts, some of which are stable and have been isolated and characterized but others polymerize spontaneously. This perspective updates present knowledge about the lipid-derived carbonyl trapping ability of phenolics, its competition with carbonyl-amine reactions produced in foods, and the presence of carbonyl-phenol adducts in food products.

  7. Characterization of Halogen Bonded Adducts in Solution by Advanced NMR Techniques

    Directory of Open Access Journals (Sweden)

    Gianluca Ciancaleoni

    2017-09-01

    Full Text Available In the last 20 years, a huge volume of experimental work into halogen bonding (XB has been produced. Most of the systems have been characterized by solid state X-ray crystallography, whereas in solution the only routine technique is titration (by using 1H and 19F nuclear magnetic resonance (NMR, infrared (IR, ultraviolet–visible (UV–Vis or Raman spectroscopies, depending on the nature of the system, with the aim of characterizing the strength of the XB interaction. Unfortunately, titration techniques have many intrinsic limitations and they should be coupled with other, more sophisticated techniques to provide an accurate and detailed description of the geometry and stoichiometry of the XB adduct in solution. This review will show how crucial information about XB adducts can be obtained by advanced NMR techniques, nuclear Overhauser effect-based spectroscopies (NOESY, ROESY, HOESY… and diffusion NMR techniques (PGSE or DOSY.

  8. TLC surface integrity affects the detection of alkali adduct ions in TLC-MALDI analysis.

    Science.gov (United States)

    Dong, Yonghui; Ferrazza, Ruggero; Anesi, Andrea; Guella, Graziano; Franceschi, Pietro

    2017-09-01

    Direct coupling of thin-layer chromatography (TLC) with matrix-assisted laser desorption ionization (MALDI) mass spectrometry allows fast and detailed characterization of a large variety of analytes. The use of this technique, however, presents great challenges in semiquantitative applications because of the complex phenomena occurring at the TLC surface. In our laboratory, we recently observed that the ion intensities of several alkali adduct ions were significantly different between the top and interior layer of the TLC plate. This indicates that the integrity of the TLC surface can have an important effect on the reproducibility of TLC- MALDI analyses. Graphical Abstract MALDI imaging reveals that surface integrity affects the detection of alkali adductions in TLC-MALDI.

  9. Lewis Acid-Base Adduct Approach for High Efficiency Perovskite Solar Cells.

    Science.gov (United States)

    Lee, Jin-Wook; Kim, Hui-Seon; Park, Nam-Gyu

    2016-02-16

    Since the first report on the long-term durable 9.7% solid-state perovskite solar cell employing methylammonium lead iodide (CH3NH3PbI3), mesoporous TiO2, and 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-MeOTAD) in 2012, following the seed technologies on perovskite-sensitized liquid junction solar cells in 2009 and 2011, a surge of interest has been focused on perovskite solar cells due to superb photovoltaic performance and extremely facile fabrication processes. The power conversion efficiency (PCE) of perovskite solar cells reached 21% in a very short period of time. Such an unprecedentedly high photovoltaic performance is due to the intrinsic optoelectronic property of organolead iodide perovskite material. Moreover, a high dielectric constant, sub-millimeter scale carrier diffusion length, an underlying ferroelectric property, and ion migration behavior can make organolead halide perovskites suitable for multifunctionality. Thus, besides solar cell applications, perovskite material has recently been applied to a variety fields of materials science such as photodetectors, light emitting diodes, lasing, X-ray imaging, resistive memory, and water splitting. Regardless of application areas, the growth of a well-defined perovskite layer with high crystallinity is essential for effective utilization of its excellent physicochemical properties. Therefore, an effective methodology for preparation of high quality perovskite layers is required. In this Account, an effective methodology for production of high quality perovskite layers is described, which is the Lewis acid-base adduct approach. In the solution process to form the perovskite layer, the key chemicals of CH3NH3I (or HC(NH2)2I) and PbI2 are used by dissolving them in polar aprotic solvents. Since polar aprotic solvents bear oxygen, sulfur, or nitrogen, they can act as a Lewis base. In addition, the main group compound PbI2 is known to be a Lewis acid. Thus, PbI2 has a chance

  10. Anomalous behaviour in the phase transition and crystal structure of urea adducts with n-eicosane

    Science.gov (United States)

    Fukao, Koji

    1996-03-01

    X-ray diffraction measurements are made for urea adducts with n-eicosane to investigate the arrangement of n-eicosane molecules in the channels formed by urea molecules. Extra Bragg reflections have been found on the layers with the 0953-8984/8/13/003/img1-coordinate corresponding to twice the chain length of the n-eicosane molecule in both the low- and high-temperature phases. This kind of Bragg reflection has not been observed for other n-alkanes in urea adducts. On the basis of the intensity distribution of the extra Bragg reflections, it is found that the n-eicosane molecules are arranged in such a way that the orientations of zigzag planes of longitudinally neighbouring molecules are anti-parallel to each other.

  11. Activation of Reactive MALDI Adduct Ions Enables Differentiation of Dihydroxylated Vitamin D Isomers

    Science.gov (United States)

    Qi, Yulin; Müller, Miriam J.; Volmer, Dietrich A.

    2017-08-01

    Vitamin D compounds are secosteroids, which are best known for their role in bone health. More recent studies have shown that vitamin D metabolites and catabolites such as dihydroxylated species (e.g., 1,25- and 24,25-dihydroxyvitamin D3) play key roles in the pathologies of various diseases. Identification of these isomers by mass spectrometry is challenging and currently relies on liquid chromatography, as the isomers exhibit virtually identical product ion spectra under collision induced dissociation conditions. Here, we developed a simple MALDI-CID method that utilizes ion activation of reactive analyte/matrix adducts to distinguish isomeric dihydroxyvitamin D3 species, without the need for chromatography separation or chemical derivatization techniques. Specifically, reactive 1,5-diaminonaphthalene adducts of dihydroxyvitamin D3 compounds formed during MADI were activated and specific cleavages in the secosteroid's backbone structure were achieved that produced isomer-diagnostic fragment ions. [Figure not available: see fulltext.

  12. Activation of Reactive MALDI Adduct Ions Enables Differentiation of Dihydroxylated Vitamin D Isomers

    Science.gov (United States)

    Qi, Yulin; Müller, Miriam J.; Volmer, Dietrich A.

    2017-12-01

    Vitamin D compounds are secosteroids, which are best known for their role in bone health. More recent studies have shown that vitamin D metabolites and catabolites such as dihydroxylated species (e.g., 1,25- and 24,25-dihydroxyvitamin D3) play key roles in the pathologies of various diseases. Identification of these isomers by mass spectrometry is challenging and currently relies on liquid chromatography, as the isomers exhibit virtually identical product ion spectra under collision induced dissociation conditions. Here, we developed a simple MALDI-CID method that utilizes ion activation of reactive analyte/matrix adducts to distinguish isomeric dihydroxyvitamin D3 species, without the need for chromatography separation or chemical derivatization techniques. Specifically, reactive 1,5-diaminonaphthalene adducts of dihydroxyvitamin D3 compounds formed during MADI were activated and specific cleavages in the secosteroid's backbone structure were achieved that produced isomer-diagnostic fragment ions. [Figure not available: see fulltext.

  13. Lactone modified mono-or dicarboxylic acid based adduct dispersant compositions

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, A.; Lundberg, R.D.

    1990-03-06

    This patent describes a C{sub 5}-C{sub 9} lactone adduct material useful as an oil additive formed by reacting an aliphatic hydrocarbyl saturated or unsaturated, natural or synthetic, straight chain or branched chain monocarboxylic or dicarboxylic acylating agent heaving from about 1 to about 165 total carbon atoms with the reaction product of a C{sub 5}-C{sub 9} lactone with a member selected from the group consisting of a polyamine having from bout 2 to 60 total carbon atoms and from about 2 to about 12 nitrogen atoms, an amino alcohol containing up to about 50 total carbon atoms, from 1 to about 5 nitrogen atoms and from 1 to about 15 hydroxyl groups, and mixtures thereof. The aliphatic acylating agent having at least about twelve carbon atoms in said straight or branched chain to produce lactone adduct material that is hydrocarbon soluble.

  14. Diastereoselective synthesis of substituted 2-amino-1,3-propanediols from Morita-Baylis-Hillman adducts

    Energy Technology Data Exchange (ETDEWEB)

    Paioti, Paulo H.S.; Rezende, Patricia; Coelho, Fernando [Laboratorio de Sintese de Produtos Naturais e Farmacos, Instituto de Quimica, Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2012-07-01

    We report herein a new diastereoselective approach to substituted 2-amino-1,3-propanediols with anti relative stereochemistry from Morita-Baylis-Hillman (MBH) adducts. These structural moieties have been used as intermediates for the synthesis of several compounds with relevant pharmacological and commercial interest. In this strategy, substituted anti 2-amino-1,3-propanediols were readily prepared via ozonolysis of allylic diols obtained from MBH adducts, followed by a diastereoselective reductive amination of the substituted 2-oxo-1,3-propanediols. To demonstrate the synthetic utility of these aminodiols, they were transformed into substituted oxazolidine-2-ones, which were also used in the indirect determination of the relative stereochemistry of the aminodiols. (author)

  15. Relationship between ambient air pollution and DNA damage in Polish mothers and newborns

    Energy Technology Data Exchange (ETDEWEB)

    Whyatt, R.M.; Santella, R.M.; Jedrychowski, W.; Garte, S.J.; Bell, D.A.; Ottman, R.; Gladek-Yarborough, A.; Cosma, G.; Young, T.L.; Cooper, T.B.; Randall, M.C.; Manchester, D.K.; Perera, F.P. [Columbia University, New York, NY (United States). Division of Environmental Health Sciences

    1998-06-01

    Industrialized regions in Poland are characterized by high ambient pollution, including polycyclic aromatic hydrocarbons (PAHs) from coal burning for industry and home heating. In experimental bioassays, certain PAHs are transplacental carcinogens and developmental toxicants. The amount of PAHs bound to DNA (PAH-DNA adducts) in maternal and umbilical white blood cells were measured in 70 mothers and newborns from Krakow, Poland. Modulation of adduct levels by genotypes previously linked to risk of lung cancer, specifically glutathione S-transferase M1(GSTM1) and cytochrome P4501A1 (CYP1A1). There was a dose-related increase in maternal and newborn adduct levels with ambient pollution at the women`s place of residence among subjects who were not employed away from home (p less than or equal to 0.05). Maternal smoking (active and passive) significantly increased maternal (p less than or equal to 0.01) but not newborn adduct levels. Results indicate that PAH-induced DNA damage in mothers and newborns is increased by ambient air pollution.

  16. SOME NEW SULFATO AND HYDROGENOSULFATO ADDUCTS: SYNTHESIS, INFRARED AND MÖSSBAUER STUDIES

    Directory of Open Access Journals (Sweden)

    Alain Wattiaux

    2010-07-01

    Full Text Available Eight organotin (IV (mainly sulfato adducts have been synthesized and studied by spectroscopic methods. While considering the anionic component, the suggested structures are discrete; supramolecular architectures are obtained with secondary interactions through NH----Cl and NH----O hydrogen bonds while considering the cations, the anions behaving as monochelating, bridging or monocoordinating ligands, the environment around the tin (IV centre being octahedral. Tetrahedral SnMe2Cl2 has been characterized spectroscopically.

  17. Postburn shoulder medial-adduction contracture: anatomy and treatment with trapeze-flap plasty.

    Science.gov (United States)

    Grishkevich, Viktor M

    2013-03-01

    Shoulder-adduction contractures after burn, most frequent among big joints, cause functional deficiency of the upper limb and, therefore, benefits from surgical correction. Many reconstructive techniques and flaps have been suggested for contracture treatment, but the problem in choosing an adequate reconstructive technique based on the anatomy of the contracture remains. Shoulder-adduction contracture has been given less emphasis in research than any other type and its surgical reconstructive technique remains of concern. Anatomic features of scar shoulder-adduction contractures were studied in 346 patients, personally operated upon. This allowed us to classify all contractures into three types: edge, medial and total. New surgical techniques specifically for medial contractures were developed. Eighty percent of patients had edge contractures in which the axillary fossa was spared. In 20% of patients, axilla, including the hairy dome, was involved. These cases were anatomically classified into two types: medial, making up 30% of the cases, when contracted scars involved only axilla, and total caused by scars, tightly surrounding the shoulder joint. The scars, causing medial contracture, form a crescent-shaped fold along the medial axillary line. The fold's sheets are scars in which there is skin surface surplus in width, which allows the contracture release with local tissues. Surface deficiency in length has a trapezoid form. Medial contracture can be successfully treated with opposite transposition of trapezoid adipose-scar flaps prepared from both sheets of the fold. Medial shoulder-adduction contracture is a newly described type with specific anatomic features. Contracture can be successfully treated with local tissues using trapeze-flap plasty. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  18. Acrylamide Hemoglobin Adduct Levels and Ovarian Cancer Risk: a nested case-control study

    Science.gov (United States)

    Xie, Jing; Terry, Kathryn L.; Poole, Elizabeth M.; Wilson, Kathryn M.; Rosner, Bernard A.; Willett, Walter C.; Vesper, Hubert W.; Tworoger, Shelley S.

    2013-01-01

    Background Acrylamide is a probable human carcinogen formed during cooking of starchy foods. Two large prospective cohort studies of dietary acrylamide intake and ovarian cancer risk observed a positive association, although two other studies reported no association. Methods We measured acrylamide exposure using red blood cell acrylamide and glycidamide hemoglobin adducts among women in two large prospective cohorts: the Nurses’ Health Study and Nurses’ Health Study II. Between blood collection and 2010, we identified 263 incident cases of epithelial ovarian cancer, matching two controls per case. We used logistic regression models to examine the association between acrylamide exposure and ovarian cancer risk, adjusting for matching factors, family history of ovarian cancer, tubal ligation, oral contraceptive use, body mass index (BMI), parity, alcohol intake, smoking, physical activity, and caffeine intake. Results The multivariate-adjusted relative risk (RR) of ovarian cancer comparing the highest versus lowest tertile of total acrylamide adducts was 0.79 (95% CI: 0.50–1.24, P trend = 0.08). The comparable RR of ovarian cancer among non-smokers at blood draw was 0.85 (95% CI: 0.57–1.27, P trend =0.14). The association did not differ by tumor histology (serous invasive versus not), P for heterogeneity=0.41. Individual adduct types (acrylamide or glycidamide) were not associated with risk. Conclusions We observed no evidence that acrylamide exposure as measured by adducts to hemoglobin is associated with an increased risk of ovarian cancer. Impact Our finding indicates that acrylamide intake may not increase risk of ovarian cancer. PMID:23417989

  19. Comparison of estimated dietary intake of acrylamide with hemoglobin adducts of acrylamide and glycidamide

    DEFF Research Database (Denmark)

    Bjellaas, Thomas; Olesen, Pelle Thonning; Frandsen, Henrik Lauritz

    2007-01-01

    /day (4.1-30.2), respectively. Non-smokers had a median AA and GA adduct concentration of 36.8 (range 17.9-65.5) and 18.2 (range 6.7-45.6) pmol/g globin, respectively. In smokers, the values were 165.8 (98.8-211) and 83.2 (29.1-99.0) pmol/g globin, respectively. Using multiple linear regression analysis...

  20. Electrochemical oxidation and protein adduct formation of aniline: a liquid chromatography/mass spectrometry study.

    Science.gov (United States)

    Melles, Daniel; Vielhaber, Torsten; Baumann, Anne; Zazzeroni, Raniero; Karst, Uwe

    2012-04-01

    Historically, skin sensitization tests are typically based on in vivo animal tests. However, for substances used in cosmetic products, these tests have to be replaced according to the European Commission regulation no. 1223/2009. Modification of skin proteins by electrophilic chemicals is a key process associated with the induction of skin sensitization. The present study investigates the capabilities of a purely instrumental setup to determine the potential of commonly used non-electrophilic chemicals to cause skin sensitization by the generation of electrophilic species from the parent compound. In this work, the electrophiles were generated by the electrochemical oxidation of aniline, a basic industrial chemical which may also be released from azo dyes in cosmetics. The compound is a known sensitizer and was oxidized in an electrochemical thin-layer cell which was coupled online to electrospray ionization-mass spectrometry. The electrochemical oxidation was performed on a boron-doped diamond working electrode, which is able to generate hydroxyl radicals in aqueous solutions at high potentials. Without any pretreatment, the oxidation products were identified by electrospray ionization/time-of-flight mass spectrometry (ESI-ToF-MS) using their exact masses. A mass voltammogram was generated by plotting the obtained mass spectra against the applied potential. Oligomerization states with up to six monomeric units in different redox states of aniline were observed using this setup. This approach was extended to generate adducts between the oxidation products of aniline and the tripeptide glutathione. Two adducts were identified with this trapping experiment. Protein modification was carried out subsequently: Aniline was oxidized at a constant potential and was allowed to react with β-lactoglobulin A (β-LGA) or human serum albumin (HSA), respectively. The generated adducts were analyzed by liquid chromatography coupled to ESI-ToF-MS. For both β-LGA and HSA, aniline

  1. Free flow electrophoresis separation and AMS quantitation of 14C-naphthalene-protein adducts

    Science.gov (United States)

    Buchholz, Bruce A.; Haack, Kurt W.; Sporty, Jennifer L.; Buckpitt, Alan R.; Morin, Dexter

    2010-04-01

    Naphthalene is a volatile aromatic hydrocarbon to which humans are exposed from a variety of sources including mobile air sources and cigarette smoke. Naphthalene produces dose-(concentration)dependent injury to airway epithelial cells of murine lung which is observed at concentrations well below the current occupational exposure standard. Toxicity is dependent upon the cytochrome P450 mediated metabolic activation of the parent substrate to unstable metabolites which become bound covalently to tissue proteins. Nearly 70 proteins have been identified as forming adducts with reactive naphthalene metabolites using in vitro systems but very little work has been conducted in vivo because reasonably large amounts (100 μCi) of 14C labeled parent compound must be administered to generate detectable adduct levels on storage phosphor screens following separation of labeled proteins by 2D gel electrophoresis. The work described here was done to provide proof of concept that protein separation by free flow electrophoresis followed by AMS detection of protein fractions containing protein bound reactive metabolites would provide adducted protein profiles in animals dosed with trace quantities of labeled naphthalene. Mice were administered 200 mg/kg naphthalene intraperitoneally at a calculated specific activity of 2 DPM/nmol (1 pCi/nmol) and respiratory epithelial tissue was obtained by lysis lavage 4 h post injection. Free flow electrophoresis (FFE) separates proteins in the liquid phase over a large pH range (2.5-11.5) using low molecular weight acids and bases to modify the pH. The apparatus separates fractions into standard 96-well plates that can be used in other protein analysis techniques. The buffers of the fractions have very high carbon content, however, and need to be dialyzed to yield buffers compatible with 14C-AMS. We describe the processing techniques required to couple FFE to AMS for quantitation of protein adducts.

  2. Free flow electrophoresis separation and AMS quantitation of {sup 14}C-naphthalene-protein adducts

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, Bruce A., E-mail: bbuchholz@llnl.go [Center for AMS, LLNL, 7000 East Avenue, Livermore, CA 94551 (United States); Haack, Kurt W.; Sporty, Jennifer L. [Center for AMS, LLNL, 7000 East Avenue, Livermore, CA 94551 (United States); Buckpitt, Alan R.; Morin, Dexter [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States)

    2010-04-15

    Naphthalene is a volatile aromatic hydrocarbon to which humans are exposed from a variety of sources including mobile air sources and cigarette smoke. Naphthalene produces dose-(concentration)dependent injury to airway epithelial cells of murine lung which is observed at concentrations well below the current occupational exposure standard. Toxicity is dependent upon the cytochrome P450 mediated metabolic activation of the parent substrate to unstable metabolites which become bound covalently to tissue proteins. Nearly 70 proteins have been identified as forming adducts with reactive naphthalene metabolites using in vitro systems but very little work has been conducted in vivo because reasonably large amounts (100 muCi) of {sup 14}C labeled parent compound must be administered to generate detectable adduct levels on storage phosphor screens following separation of labeled proteins by 2D gel electrophoresis. The work described here was done to provide proof of concept that protein separation by free flow electrophoresis followed by AMS detection of protein fractions containing protein bound reactive metabolites would provide adducted protein profiles in animals dosed with trace quantities of labeled naphthalene. Mice were administered 200 mg/kg naphthalene intraperitoneally at a calculated specific activity of 2 DPM/nmol (1 pCi/nmol) and respiratory epithelial tissue was obtained by lysis lavage 4 h post injection. Free flow electrophoresis (FFE) separates proteins in the liquid phase over a large pH range (2.5-11.5) using low molecular weight acids and bases to modify the pH. The apparatus separates fractions into standard 96-well plates that can be used in other protein analysis techniques. The buffers of the fractions have very high carbon content, however, and need to be dialyzed to yield buffers compatible with {sup 14}C-AMS. We describe the processing techniques required to couple FFE to AMS for quantitation of protein adducts.

  3. Synthesis of polymeric derivatives of isoniazid: characterization and in vitro release from a water-soluble adduct with polysuccinimide.

    Science.gov (United States)

    Giammona, G; Giannola, L I; Carlisi, B

    1989-04-01

    Coupling of isoniazid with polysuccinimide afforded a water-insoluble polymeric pro-drug; by reaction with ethanolamine it was chemically transformed in a water-soluble adduct. The in vitro release of isoniazid from the drug-polymer adduct was studied by using an artificial stomach wall lipid membrane. The transfer rate constant from simulated gastric juice to simulated plasma was defined and compared with that of an equivalent dose of pure drug.

  4. Amadori adducts activate nuclear factor-kappaB-related proinflammatory genes in cultured human peritoneal mesothelial cells.

    Science.gov (United States)

    Nevado, Julián; Peiró, Concepción; Vallejo, Susana; El-Assar, Mariam; Lafuente, Nuria; Matesanz, Nuria; Azcutia, Verónica; Cercas, Elena; Sánchez-Ferrer, Carlos F; Rodríguez-Mañas, Leocadio

    2005-09-01

    Diabetes mellitus leads to a high incidence of several so-called complications, sharing similar pathophysiological features in several territories. Previous reports points at early nonenzymatic glycosylation products (Amadori adducts) as mediators of diabetic vascular complications. In the present study, we analysed a possible role for Amadori adducts as stimulators of proinflammatory pathways in human peritoneal mesothelial cells (HPMCs). Cultured HPMCs isolated from 13 different patients (mean age 38.7+/-16 years) were exposed to different Amadori adducts, that is, highly glycated haemoglobin (10 nM) and glycated bovine serum albumin (0.25 mg ml(-1)), as well as to their respective low glycosylation controls. Amadori adducts, but not their respective controls, elicited a marked increase of NF-kappaB activation, as determined by electromobility shift assays and transient transfection experiments. Additionally, Amadori adducts significantly increased the production of NF-kappaB-related proinflammatory molecules, including cytokines, such as TNF-alpha, IL-1beta or IL-6, and enzymes, such as cyclooxygenase-2 and inducible nitric oxide (NO) synthase, this latter leading to the release of NO by HPMCs. The effects of Amadori adducts were mediated by different reactive oxygen and nitrosative species (e.g. superoxide anions, hydroxyl radicals, and peroxynitrite), as they were blunted by coincubation with the appropriate scavengers. Furthermore, NO generated upon exposure to Amadori adducts further stimulated NF-kappaB activation, either directly or after combination with superoxide anions to form peroxynitrite. We conclude that Amadori adducts can favour peritoneal inflammation by exacerbating changes in NO synthesis pathway and triggering NF-kappaB-related proinflammatory signals in human mesothelial cells.

  5. Amadori adducts activate nuclear factor-κB-related proinflammatory genes in cultured human peritoneal mesothelial cells

    Science.gov (United States)

    Nevado, Julián; Peiró, Concepción; Vallejo, Susana; El-Assar, Mariam; Lafuente, Nuria; Matesanz, Nuria; Azcutia, Veronica; Cercas, Elena; Sánchez-Ferrer, Carlos F; Rodríguez-Mañas, Leocadio

    2005-01-01

    Diabetes mellitus leads to a high incidence of several so-called complications, sharing similar pathophysiological features in several territories. Previous reports points at early nonenzymatic glycosylation products (Amadori adducts) as mediators of diabetic vascular complications. In the present study, we analysed a possible role for Amadori adducts as stimulators of proinflammatory pathways in human peritoneal mesothelial cells (HPMCs). Cultured HPMCs isolated from 13 different patients (mean age 38.7±16 years) were exposed to different Amadori adducts, that is, highly glycated haemoglobin (10 nM) and glycated bovine serum albumin (0.25 mg ml−1), as well as to their respective low glycosylation controls. Amadori adducts, but not their respective controls, elicited a marked increase of NF-κB activation, as determined by electromobility shift assays and transient transfection experiments. Additionally, Amadori adducts significantly increased the production of NF-κB-related proinflammatory molecules, including cytokines, such as TNF-α, IL-1β or IL-6, and enzymes, such as cyclooxygenase-2 and inducible nitric oxide (NO) synthase, this latter leading to the release of NO by HPMCs. The effects of Amadori adducts were mediated by different reactive oxygen and nitrosative species (e.g. superoxide anions, hydroxyl radicals, and peroxynitrite), as they were blunted by coincubation with the appropriate scavengers. Furthermore, NO generated upon exposure to Amadori adducts further stimulated NF-κB activation, either directly or after combination with superoxide anions to form peroxynitrite. We conclude that Amadori adducts can favour peritoneal inflammation by exacerbating changes in NO synthesis pathway and triggering NF-κB-related proinflammatory signals in human mesothelial cells. PMID:15997235

  6. Immune Responses of Wistar Rat (Rattus novergicus on Adduction of Humid Acid from Borneo Peat Soil

    Directory of Open Access Journals (Sweden)

    Diah Wulandari Rousdy

    2016-11-01

    Full Text Available Peat soil is a type of soil that dominates the island of Borneo. Typical compounds in peat soil is humic acid. Various in vitro studies performed have shown peat subtropical humic compounds can stimulate the immune system. However, in vivo study on animal has not been done. This study aimed to determine the effect of humic acid extracted from peat soil of Borneo against the immune system, both of non-specific and specific immunity Wistar rats (Rattus novergicus. Research using a completely randomized design with five treatments and five replicates, the normal controls, a positive control (isoprinosine, humic acid 125; 250; 500 mg/kg. Humic acid was administered orally for 10 days. The results showed humic acid adduction did not significantly affect levels of hemoglobin, erythrocytes and hematocrit. Humic acid adduction of 125 mg/kg significantly affects the total leukocyte count and differential leukocyte. Humic acid 125 mg/kg also showed increased phagocytic index better than normal controls. All humic acid treatments do not provide a significant effect on the total amount of antibody. The results of this study can be used for the development of Borneo tropical peat resources as natural imunostimulant.How to CiteRousdy, D. W., Rahmawati, R. & Kurniatuhadi, R. (2016. Immune Responses of Wistar Rat (Rattus novergicus on Adduction of Humid Acid from Borneo Peat Soil. Biosaintifika: Journal of Biology & Biology Education, 8(3, 401-406. 

  7. Characterization and reactivity of a terminal nickel(III)-oxygen adduct.

    Science.gov (United States)

    Pirovano, Paolo; Farquhar, Erik R; Swart, Marcel; Fitzpatrick, Anthony J; Morgan, Grace G; McDonald, Aidan R

    2015-02-23

    High-valent terminal metal-oxygen adducts are hypothesized to be the potent oxidizing reactants in late transition metal oxidation catalysis. In particular, examples of high-valent terminal nickel-oxygen adducts are scarce, meaning there is a dearth in the understanding of such oxidants. A monoanionic Ni(II)-bicarbonate complex has been found to react in a 1:1 ratio with the one-electron oxidant tris(4-bromophenyl)ammoniumyl hexachloroantimonate, yielding a thermally unstable intermediate in high yield (ca. 95%). Electronic absorption, electronic paramagnetic resonance, and X-ray absorption spectroscopies and density functional theory calculations confirm its description as a low-spin (S = 1/2), square planar Ni(III)-oxygen adduct. This rare example of a high-valent terminal nickel-oxygen complex performs oxidations of organic substrates, including 2,6-di-tert-butylphenol and triphenylphosphine, which are indicative of hydrogen atom abstraction and oxygen atom transfer reactivity, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Mechanism of arylating quinone toxicity involving Michael adduct formation and induction of endoplasmic reticulum stress.

    Science.gov (United States)

    Wang, Xinhe; Thomas, Beena; Sachdeva, Rakesh; Arterburn, Linnea; Frye, Lucy; Hatcher, Patrick G; Cornwell, David G; Ma, Jiyan

    2006-03-07

    Quinones permeate our biotic environment, contributing to both homeostasis and cytotoxicity. All quinones generate reactive oxygen species through redox cycling, while partially substituted quinones also undergo arylation (Michael adduct formation) yielding covalent bonds with nucleophiles such as cysteinyl thiols. In contrast to reactive oxygen species, the role of arylation in quinone cytotoxicity is not well understood. We found that the arylating quinones, including unsubstituted 1,4-benzoquinone (1,4-BzQ) and partially substituted vitamin E congener gamma-tocopherol quinone (gamma-TQ), were cytotoxic, with gamma-TQ > 1,4-BzQ, whereas the fully substituted nonarylating vitamin E congener alpha-tocopherol quinone was not. In vitro, both arylating quinones formed Michael adducts with the thiol nucleophile N-acetylcysteine (NAC) at rates where 1,4-BzQ > gamma-TQ. In cultured cells, concurrent addition of NAC eliminated 1,4-BzQ caused toxicity, but preincubation was required for the same NAC detoxification effect on gamma-TQ. These data clearly established the role of arylation in quinone toxicity and revealed that arylating quinone structure affects cytotoxicity by governing detoxification through the rate of adduct formation. Furthermore, arylating quinones induced endoplasmic reticulum (ER) stress by activating the pancreatic ER kinase (PERK) signaling pathway including elF2alpha, ATF4, and C/EBP homologous protein (CHOP). Detoxification by NAC greatly attenuates CHOP induction in arylating quinone-treated cells, suggesting that ER stress is a cellular mechanism for arylating quinone cytotoxicity.

  9. Gingival tissue, an extrasynovial source of malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins.

    Science.gov (United States)

    Bright, R; Thiele, G M; Manavis, J; Mikuls, T R; Payne, J B; Bartold, P M

    2017-10-17

    Postranslational modification of proteins can lead to the production of autoantibodies and loss of immune tolerance. This process has been hypothesised to be a critical factor in the pathogenesis of rheumatoid arthritis. The objective of this study was to demonstrate that inflamed human gingival tissue provides an extrasynovial source of malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins all of which are considered to be linked to the development of rheumatoid arthritis. Identification of such modified proteins in inflamed gingiva may explain, in part, how inflammation of the periodontal tissues may influence the development of rheumatoid arthritis. Gingival biopsies of healthy, mild and moderate periodontitis were triple stained with antibodies against malondialdehyde-acetaldehyde adducts, citrullinated and carbamylated proteins. Assessment of healthy gingival tissue revealed negligible staining for carbamylated, malondialdehyde-acetaldehyde (MAA), or citrullinated proteins. Mild periodontitis was positive for all three modifications. Furthermore, there was an increase in staining intensity for carbamylated, citrullinated and MAA-modified proteins in moderate periodontitis. Negative staining results were observed for the isotype controls. This study provides evidence for the presence of citrullinated, carbamylated and MAA adduct modified proteins in inflamed periodontal tissues. The potential for these proteins to play a role in autoimmunity in a multi-system inflammatory syndromic disease model now needs to be determined. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. The application of psoralens to the study of DNA structure, function and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Spielmann, Peter Hans [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1991-04-01

    A series of six nitroxide spin-labeled psoralens were designed, synthesized and tested as probes for DNA dynamics. The synthesis of these spin-labeled psoralen derivatives and their photoreactivity with double-stranded DNA fragments is described. The spin labels (nitroxides) were demonstrated to survive the uv irradiation required to bind the probe to the target DNA. EPR spectra of the photobound spin-labels indicate that they do not wobble with respect to the DNA on the time-scales investigated. The author has used psoralen modified DNA as a model for the study of DNA repair enzyme systems in human cell free extracts. He has shown that damage-induced DNA synthesis is associated with removal of psoralen adducts and therefore is "repair synthesis" and not an aberrant DNA synthesis reaction potentiated by deformation of the DNA by adducts. He has found that all DNA synthesis induced by psoralen monoadducts is the consequence of removal of these adducts. By the same approach he has obtained evidence that this in vitro system is capable of removing psoralen cross-links as well. Reported here are synthetic methods that make use of high intensity lasers coupled with HPLC purification to make homogeneous and very pure micromole quantities of furan-side monoadducted, cross-linked, and pyrone-side monoadducted DNA oligonucleotide. These molecules are currently being studied by NMR and X-ray crystallography. The application of the site-specifically psoralen modified oligonucleotide synthesized by these methods to the construction of substrates for the investigation of DNA repair is also discussed.

  11. Effect of 2, 5-Substituents on the Stability of Cyclic Nitrone Superoxide Spin Adducts: A Density Functional Theory Approach

    Science.gov (United States)

    Du, Li-Bo; Wang, Lan-Fen; Liu, Yang-Ping; Jia, Hong-Ying; Liu, Yang; Liu, Ke Jian; Tian, Qiu

    2011-01-01

    To design efficient spin traps for superoxide radicals, interest in the elucidation of substituent effects on the stability of superoxide spin adducts has become a necessary priority. In the present study, five cyclic nitrone superoxide spin adducts, i.e. DMPO-OOH, M3PO-OOH, EMPO-OOH, DEPMPO-OOH, and DEPDMPO-OOH, were chosen as model compounds to investigate the effect of 2,5-subsitituents on their stability, through structural analysis and decay thermodynamics using density functional theory (DFT) calculations. Analysis of the optimized geometries reveals that none of the previously proposed stabilizing factors, including intramolecular H-bonds, intramolecular nonbonding interactions, bulky steric protection, nor the C(2)–N(1) bond distance can be used to clearly explain the effect of 2,5-substituents on the stability of the spin adducts. Additionally the effect of the 2,5-substituents on the stability of the superoxide spin adducts cannot be simply clarified by Milliken charges on both atoms (nitroxyl nitrogen and nitroxyl oxygen). Subsequent study found that spin densities on the nitroxyl nitrogen and oxygen are well correlated with the half-life times of the spin adducts, and consequently are the proper parameters to characterize the effect of 2,5-substituents on their stability. Examination of the decomposition thermodynamics further supports the effect of the substituents on the persistence of cyclic nitrone superoxide spin adducts. PMID:20370568

  12. Characterization of glycidol-hemoglobin adducts as biomarkers of exposure and in vivo dose

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Hiroshi, E-mail: honda.hiroshi@kao.co.jp [R and D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497 (Japan); Törnqvist, Margareta [Department of Materials and Environmental Chemistry, Environmental Chemistry Unit, Stockholm University, SE-106 91 Stockholm (Sweden); Nishiyama, Naohiro [R and D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497 (Japan); Kasamatsu, Toshio, E-mail: kasamatsu.toshio@kao.co.jp [R and D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497 (Japan)

    2014-03-15

    Hemoglobin adducts have been used as biomarkers of exposure to reactive chemicals. Glycidol, an animal carcinogen, has been reported to form N-(2,3-dihydroxy-propyl)valine adducts to hemoglobin (diHOPrVal). To support the use of these adducts as markers of glycidol exposure, we investigated the kinetics of diHOPrVal formation and its elimination in vitro and in vivo. Five groups of rats were orally administered a single dose of glycidol ranging from 0 to 75 mg/kg bw, and diHOPrVal levels were measured 24 h after administration. A dose-dependent increase in diHOPrVal levels was observed with high linearity (R{sup 2} = 0.943). Blood sampling at different time points (1, 10, 20, or 40 days) from four groups administered glycidol at 12 mg/kg bw suggested a linear decrease in diHOPrVal levels compatible with the normal turnover of rat erythrocytes (life span, 61 days), with the calculated first-order elimination rate constant (k{sub el}) indicating that the diHOPrVal adduct was chemically stable. Then, we measured the second-order rate constant (k{sub val}) for the reaction of glycidol with N-terminal valine in rat and human hemoglobin in in vitro experiments with whole blood. The k{sub val} was 6.7 ± 1.1 and 5.6 ± 1.3 (pmol/g globin per μMh) in rat and human blood, respectively, indicating no species differences. In vivo doses estimated from k{sub val} and diHOPrVal levels were in agreement with the area under the (concentration–time) curve values determined in our earlier toxicokinetic study in rats. Our results indicate that diHOPrVal is a useful biomarker for quantification of glycidol exposure and for risk assessment. - Highlight: • Glycidol-hemoglobin adduct (diHOPrVal) was characterized for exposure evaluation. • We studied the kinetics of diHOPrVal formation and elimination in vitro and in vivo. • Dose dependent formation and chemical stability were confirmed in the rat study. • In vivo dose (AUC) of glycidol could be estimated from diHOPrVal levels

  13. Accelerated repair and reduced mutagenicity of DNA damage induced by cigarette smoke in human bronchial cells transfected with E.coli formamidopyrimidine DNA glycosylase.

    Directory of Open Access Journals (Sweden)

    Mara Foresta

    Full Text Available Cigarette smoke (CS is associated to a number of pathologies including lung cancer. Its mutagenic and carcinogenic effects are partially linked to the presence of reactive oxygen species and polycyclic aromatic hydrocarbons (PAH inducing DNA damage. The bacterial DNA repair enzyme formamidopyrimidine DNA glycosylase (FPG repairs both oxidized bases and different types of bulky DNA adducts. We investigated in vitro whether FPG expression may enhance DNA repair of CS-damaged DNA and counteract the mutagenic effects of CS in human lung cells. NCI-H727 non small cell lung carcinoma cells were transfected with a plasmid vector expressing FPG fused to the Enhanced Green Fluorescent Protein (EGFP. Cells expressing the fusion protein EGFP-FPG displayed accelerated repair of adducts and DNA breaks induced by CS condensate. The mutant frequencies induced by low concentrations of CS condensate to the Na(+K(+-ATPase locus (oua(r were significantly reduced in cells expressing EGFP-FPG. Hence, expression of the bacterial DNA repair protein FPG stably protects human lung cells from the mutagenic effects of CS by improving cells' capacity to repair damaged DNA.

  14. Mechanistic Studies with DNA Polymerases Reveal Complex Outcomes following Bypass of DNA Damage

    Directory of Open Access Journals (Sweden)

    Robert L. Eoff

    2010-01-01

    Full Text Available DNA is a chemically reactive molecule that is subject to many different covalent modifications from sources that are both endogenous and exogenous in origin. The inherent instability of DNA is a major obstacle to genomic maintenance and contributes in varying degrees to cellular dysfunction and disease in multi-cellular organisms. Investigations into the chemical and biological aspects of DNA damage have identified multi-tiered and overlapping cellular systems that have evolved as a means of stabilizing the genome. One of these pathways supports DNA replication events by in a sense adopting the mantra that one must “make the best of a bad situation” and tolerating covalent modification to DNA through less accurate copying of the damaged region. Part of this so-called DNA damage tolerance pathway involves the recruitment of specialized DNA polymerases to sites of stalled or collapsed replication forks. These enzymes have unique structural and functional attributes that often allow bypass of adducted template DNA and successful completion of genomic replication. What follows is a selective description of the salient structural features and bypass properties of specialized DNA polymerases with an emphasis on Y-family members.

  15. Structure of an aprataxin-DNA complex with insights into AOA1 neurodegenerative disease

    Energy Technology Data Exchange (ETDEWEB)

    Tumbale, Percy; Appel, C Denise; Kraehenbuehl, Rolf; Robertson, Patrick D; Williams, Jessica S; Krahn, Joe; Ahel, Ivan; Williams, R Scott [NIEHS; (Manchester)

    2012-09-17

    DNA ligases finalize DNA replication and repair through DNA nick-sealing reactions that can abort to generate cytotoxic 5'-adenylation DNA damage. Aprataxin (Aptx) catalyzes direct reversal of 5'-adenylate adducts to protect genome integrity. Here the structure of a Schizosaccharomyces pombe Aptx-DNA-AMP-Zn2+ complex reveals active site and DNA interaction clefts formed by fusing a histidine triad (HIT) nucleotide hydrolase with a DNA minor groove-binding C2HE zinc finger (Znf). An Aptx helical 'wedge' interrogates the base stack for sensing DNA ends or DNA nicks. The HIT-Znf, the wedge and an '[F/Y]PK' pivot motif cooperate to distort terminal DNA base-pairing and direct 5'-adenylate into the active site pocket. Structural and mutational data support a wedge-pivot-cut HIT-Znf catalytic mechanism for 5'-adenylate adduct recognition and removal and suggest that mutations affecting protein folding, the active site pocket and the pivot motif underlie Aptx dysfunction in the neurodegenerative disorder ataxia with oculomotor apraxia 1 (AOA1).

  16. Deoxyribonuclease I footprinting reveals different DNA binding modes of bifunctional platinum complexes.

    Science.gov (United States)

    Chválová, Katerina; Kaspárková, Jana; Farrell, Nicholas; Brabec, Viktor

    2006-08-01

    Deoxyribonuclease I (DNase I) footprinting methodology was used to analyze oligodeoxyribonucleotide duplexes containing unique and single, site-specific adducts of trinuclear bifunctional platinum compound, [{trans-PtCl(NH3)2}2 mu-trans-Pt(NH3)2{H2N(CH2)6NH2}2]4+ (BBR3464) and the results were compared with DNase I footprints of some adducts of conventional mononuclear cis-diamminedichloroplatinum(II) (cisplatin). These examinations took into account the fact that the local conformation of the DNA at the sites of the contacts of DNase I with DNA phosphates, such as the minor groove width and depth, sequence-dependent flexibility and bendability of the double helix, are important determinants of sequence-dependent binding to and cutting of DNA by DNase I. It was shown that various conformational perturbations induced by platinum binding in the major groove translated into the minor groove, allowing their detection by DNase I probing. The results also demonstrate the very high sensitivity of DNase I to DNA conformational alterations induced by platinum complexes so that the platinum adducts which induce specific local conformational alterations in DNA are differently recognized by DNase I.

  17. Detection of human butyrylcholinesterase-nerve gas adducts by liquid chromatography-mass spectrometric analysis after in gel chymotryptic digestion.

    Science.gov (United States)

    Tsuge, Kouichiro; Seto, Yasuo

    2006-06-21

    To verify the exposure to nerve gas, a method for detecting human butyrylcholinesterase (BuChE)-nerve gas adduct was developed using LC-electrospray mass spectrometry (ESI-MS). Purified human serum BuChE was incubated with sarin, soman or VX, and the adduct was purified by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and digested in gel by treatment with chymotrypsin. The resulting peptide mixture was subjected to LC-ESI-MS. From the chymotryptic digest of untreated human BuChE, one peak corresponding to the peptide fragment containing the active center serine residue was detected on the extracted ion chromatogram at m/z 948.5, and the sequence was ascertained to be "GESAGAASVSL" by MS/MS analysis. From the chymotryptic digest of the human BuChE-sarin adduct, a singly charged peptide peak was detected on the extracted ion chromatogram at m/z 1,069.5, and the sequence was ascertained to be "GEXAGAASVSL" by MS/MS analysis (X denotes isopropylmethylphosphonylated serine). The difference in molecular weight (120.0 Da) between the active center peptide fragments corresponding to the untreated BuChE and BuChE-sarin adduct was assumed to be derived from the addition of an isopropyl methylphosphonyl moiety to the serine residue. The formation of human BuChE adducts with soman, VX and an aged soman adduct was confirmed by detecting the respective active center peptide fragments using LC-ESI-MS. To apply the established method to an actual biological sample, human serum was incubated with VX, and the adduct was purified by procainamide affinity chromatography followed by SDS-PAGE. After chymotryptic in gel digestion, the ethylphosphonylated active center peptide fragment could be detected, and the structure of the residue was ascertained by LC-ESI-MS analysis.

  18. Further development of 32P-postlabeling for the detection of alkylphosphotriesters: evidence for the long-term nonrandom persistence of ethyl-phosphotriester adducts in vivo.

    Science.gov (United States)

    Le Pla, Rachel C; Guichard, Yves; Bowman, Karen J; Gaskell, Margaret; Farmer, Peter B; Jones, George D D

    2004-11-01

    DNA phosphate oxygens are sites for alkylation leading to phosphotriester adducts (PTEs). PTEs are reported to be both abundant and persistent and so may serve as long-term markers of genotoxicity. Previously, we reported a 32P-postlabeling assay for the specific detection of PTEs plus identification of nucleosides located 5' to PTEs. Using this, we demonstrated the nonrandom nature of ethyl-PTEs (Et-PTEs) in vivo, these results being suggestive of either the nonrandom formation of Et-PTEs in vivo or sequence specific Et-PTE repair. Presently, we report the further development and validation of the 32P-postlabeling assay, to permit the more straightforward determination of nucleosides 5' to PTEs and, using this, have investigated the long-term persistence of PTEs in vivo. Analysis of liver DNA of mice treated in vivo with N-nitrosodiethylamine reveals an initial decline in the level of Et-PTEs (t1/2PTEs remaining 4 and 56 days after treatment, respectively. From this, we conclude that Et-PTEs are suitable as long-term markers of genotoxic exposure and that putative PTE repair is not responsible for their nonrandom manifestation. However, the possibility of active repair contributing to the initial decline of Et-PTEs is considered.

  19. DNA adductomics to study the genotoxic effects of red meat consumption with and without added animal fat in rats.

    Science.gov (United States)

    Hemeryck, Lieselot Y; Van Hecke, Thomas; Vossen, Els; De Smet, Stefaan; Vanhaecke, Lynn

    2017-09-01

    Digestion of red and processed meat has been linked to the formation of genotoxic N-nitroso compounds (NOCs) and lipid peroxidation products (LPOs) in the gut. In this study, rats were fed a meat based diet to compare the possible genotoxic effects of red vs. white meat, and the interfering role of dietary fat. To this purpose, liver, duodenum and colon DNA adductomes were analyzed with UHPLC-HRMS. The results demonstrate that the consumed meat type alters the DNA adductome; the levels of 22 different DNA adduct types significantly increased upon the consumption of beef (compared to chicken) and/or lard supplemented beef or chicken. Furthermore, the chemical constitution of the retrieved DNA adducts hint at a direct link with an increase in NOCs and LPOs upon red (and processed) meat digestion, supporting the current hypotheses on the causal link between red and processed meat consumption and the development of colorectal cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Synthesis and Characterization of the Adducts of Morpholinedithioccarbamate Complexes of Oxovanadium (IV, Nickel(II, and Copper(II with Piperidine and Morpholine

    Directory of Open Access Journals (Sweden)

    Mousami Sharma

    2012-01-01

    Full Text Available A series of 1:1 adducts of bis(morpholinedithiocarbamato complex of VO(IV, 1:1 and 1:2 adducts of bis(morpholinedithiocarbamato complexes of Ni(II and Cu(II with piperidine and morpholine have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility, IR, UV-Vis, and TGA/DTA techniques. Analytical data reveals that VO(IV complex forms only 1:1 adducts with the formula [VO(morphdtc2L].H2O while Ni(II and Cu(II complexes form both 1:1 and 1:2 adducts with 1:1 adducts having general formula Ni(morphdtc2.L and Cu(morphdtc2.L and 1:2 adducts having general formula Ni(morphdtc2.L2 and Cu(morphdtc2.L2 (morphdtc = morpholinedithiocarbamate, L = morpholine and piperidine. Antifungal activity of some complexes has been carried out against the fungal strain Fusarium oxysporium. Thermal studies indicate a continuous weight loss. A square pyramidal geometry has been proposed for the 1:1 adducts of Ni(II and Cu(II complexes while an octahedral geometry has been proposed for the 1:1 adducts of VO(IV and for the 1:2 adducts of Ni(II and Cu(II complexes.

  1. Kinetics of hydroperoxy radical reactions with acetone/HO2 adduct and with acetonylperoxy radical

    Science.gov (United States)

    Grieman, F. J.; VanDerGeest, K.; Newenhouse, E.; Watkins, K.; Noell, A. C.; Hui, A.; Sander, S. P.; Okumura, M.

    2013-12-01

    Reactions of hydroperoxy radical, HO2, with acetone and with acetonylperoxy radical, CH3C(O)CH2OO, may play an important role in the oxidation chemistry of the troposphere. Using a temperature-controlled slow-flow tube cell and laser flash photolysis of Cl2 to produce HO2 and CH3C(O)CH2OO from methanol and acetone, respectively, we studied the chemical kinetics involved over the temperature range of 215 to 298 K at 100 Torr. Rates of chemical reactions were determined by monitoring the HO2 concentration as a function of time by near-IR diode laser wavelength modulation spectroscopy. (See Fig.1.) The primary reactions are rapid (reactions to form the adducts HO2-CH3OH and HO2-CH3C(O)CH3 followed by HO2 reactions with itself, the adducts (chaperone mechanisms), and acetonylperoxy radical. The equilibrium constants for adduct formation were determined in previous work.1,2 In this work, rate coefficients were determined for the acetone chaperone mechanism over the entire temperature range. (E.g., see Fig. 2.) The rate coefficients and energies obtained are very similar to those found for the methanol case.1 Rate coefficients for the CH3C(O)CH2OO/HO2 reaction were also determined over a smaller temperature range, extending the measured value beyond room temperature, and yielding an activation energy. 1. Christensen et al. J. Phys. Chem. A 2006, 110, 6948-6959. 2. Grieman et al. J. Phys. Chem. A 2011, 115, 10527-10538. Fig.1. HO2 decay for HO2/Acetone chemistry at T = 298 K. Fig.2. Determining rate coefficient (k") for HO2/acetone chaperone effect at T = 222.5 K.

  2. Shutdown potential adjustment of modified carbene adducts as additives for lithium ion battery electrolytes

    Science.gov (United States)

    Janssen, Pia; Streipert, Benjamin; Krafft, Roman; Murmann, Patrick; Wagner, Ralf; Lewis-Alleyne, Lesley; Röschenthaler, Gerd-Volker; Winter, Martin; Cekic-Laskovic, Isidora

    2017-11-01

    To improve the intrinsic safety of lithium ion batteries (LIBs) by preventing cells from a thermal runaway, we studied two carbene adduct electrolyte additives. The recently synthesized compounds (1,3-dimethylimidazolidin-2-μm-trifluoroborate (NHC-BF3) and 1,3-dimethylimidazolidin-2-μm-tetrafluorotrifluoromethylphosphate (NHC-PF4CF3)) were investigated on LiNi1/3Co1/3Mn1/3O2 (NMC111) electrodes in Li metal and Li-ion cell setups as overcharge protection shutdown additives in 1M LiPF6 in EC:DEC (3:7, by wt.) electrolyte. By varying the NHC-ligand (-BF3, -PF5, -PF4CF3) in the molecule, the shutdown potential of the investigated carbene adduct electrolyte additives can be tailored for specific applications with different cut-off potentials. NHC-BF3 was identified as a promising candidate for the application with NMC111 electrodes up to 4.4 V vs. Li/Li+, whereas the carbene adduct NHC-PF4CF3 is ideal for the high-voltage application with the NMC-based electrode up to 4.6 V vs. Li/Li+. Next to electrochemical investigations in NMC111/Li and NMC111/graphite cells, Atomic Force Microscopy (AFM) and X-Ray Photoelectron Spectroscopy (XPS) were performed to verify the presence of a decomposition layer on the cathode, responsible for the shutdown effect. Furthermore, it has been proven that the investigated electrolyte additives have no influence on the cell performance under normal conditions in both, Li metal and Li-ion cell setups.

  3. Pneumatic Multi-Pocket Elastomer Actuators for Metacarpophalangeal Joint Flexion and Abduction-Adduction

    Directory of Open Access Journals (Sweden)

    Tapio Veli Juhani Tarvainen

    2017-09-01

    Full Text Available During recent years, interest has been rising towards developing fluidic fiber-reinforced elastomer actuators for wearable soft robotics used in hand rehabilitation and power-assist. However, they do not enable finger abduction-adduction, which plays an important role in activities of daily living, when grasping larger objects. Furthermore, the developed gloves often do not have separate control of joints, which is important for doing various common rehabilitation motions. The main obstacle for the development of a fully-assisting glove is moving a joint with multiple degrees of freedom. If the functions are built into the same structure, they are naturally coupled and affect each other, which makes them more difficult to design and complex to control than a simple flexion-extension actuator. In this study, we explored the key design elements and fabrication of pneumatic multi-pocket elastomer actuators for a soft rehabilitation glove. The goal was to gain more control over the metacarpophalangeal joint’s response by increasing the degree of actuation. Three main functional designs were tested for achieving both flexion and abduction-adduction. Five prototypes, with four different actuator geometries and four different reinforcement types, were designed and fabricated. They were evaluated by recording their free motion with motion capture and measuring their torque output using a dummy finger. Results showed the strengths and weaknesses of each design in separating the control of the two functions. We discuss the different improvements that are needed in order to make each design plausible for developing an actuator that meets the requirements for full assist of the hand’s motions. In conclusion, we show that it is possible to produce multi-pocket actuators for assisting MCP joint motion in both flexion and abduction-adduction, although coupling between the separate functions is still problematic and should be considered further.

  4. Structural identification of imatinib cyanide adducts by mass spectrometry and elucidation of bioactivation pathway.

    Science.gov (United States)

    Li, Austin C; Yu, Erya; Ring, Steven C; Chovan, James P

    2014-01-15

    Recent publications have reported that imatinib forms cyanide and methoxylamine adducts in vitro but without detail structural identification. The current work reports the identification of seven cyanide adducts that elucidate the bioactivation pathways and may provide hints for observed clinical adverse effects of the drug. Imatinib was incubated with human liver microsomal proteins in the presence of a NADPH-regeneration system and the trapping agents reduced GSH, potassium cyanide and methoxylamine. Samples were analyzed by high-performance liquid chromatography (HPLC) coupled with a LTQ-Orbitrap data collection system. Chemical structures were determined and/or postulated based on data-dependent high-resolution tandem mass spectrometric (MS(n)) exact mass measurements in both positive and negative scan modes, as well as in combination with hydrogen-deuterium exchange (HDX). GSH and methoxylamine conjugates were either not detected or were in insufficient quantities for characterization. However, seven cyanide conjugates were identified, indicating that the piperazine and p-toluidine partial structures in imatinib can become bioactivated and subsequently trapped by the nucleophile cyanide ion. The reactive intermediates were postulated as imine and imine-carbonyl conjugate (α,β-unsaturated) structures on the piperazine ring, and imine-methide on the p-toluidine partial structure. Chemical structures of seven cyanide adducts of imatinib have been identified or proposed based on high-resolution MS/MS data. Mechanisms for the formation of the conjugates were also proposed. The findings may help to understand the mechanism of hepatotoxicity of imatinib in humans. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Modelling knee flexion effects on joint power absorption and adduction moment.

    Science.gov (United States)

    Nagano, Hanatsu; Tatsumi, Ichiroh; Sarashina, Eri; Sparrow, W A; Begg, Rezaul K

    2015-12-01

    Knee osteoarthritis is commonly associated with ageing and long-term walking. In this study the effects of flexing motions on knee kinetics during stance were simulated. Extended knees do not facilitate efficient loading. It was therefore, hypothesised that knee flexion would promote power absorption and negative work, while possibly reducing knee adduction moment. Three-dimensional (3D) position and ground reaction forces were collected from the right lower limb stance phase of one healthy young male subject. 3D position was sampled at 100 Hz using three Optotrak Certus (Northern Digital Inc.) motion analysis camera units, set up around an eight metre walkway. Force plates (AMTI) recorded ground reaction forces for inverse dynamics calculations. The Visual 3D (C-motion) 'Landmark' function was used to change knee joint positions to simulate three knee flexion angles during static standing. Effects of the flexion angles on joint kinetics during the stance phase were then modelled. The static modelling showed that each 2.7° increment in knee flexion angle produced 2.74°-2.76° increments in knee flexion during stance. Increased peak extension moment was 6.61 Nm per 2.7° of increased knee flexion. Knee flexion enhanced peak power absorption and negative work, while decreasing adduction moment. Excessive knee extension impairs quadriceps' power absorption and reduces eccentric muscle activity, potentially leading to knee osteoarthritis. A more flexed knee is accompanied by reduced adduction moment. Research is required to determine the optimum knee flexion to prevent further damage to knee-joint structures affected by osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Feasibility of vocal fold abduction and adduction assessment using cine-MRI.

    Science.gov (United States)

    Baki, Marina Mat; Menys, Alex; Atkinson, David; Bassett, Paul; Morley, Simon; Beale, Timothy; Sandhu, Guri; Naduvilethil, Georgekutty; Stevenson, Nicola; Birchall, Martin A; Punwani, Shonit

    2017-02-01

    Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) METHODS: Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. • Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction. • New quantitative metrics are derived from VF position and abduction potential. • Cine-MRI able to depict the difference between normal and abnormal VF mobility. • Cine-MRI derived quantitative metrics have good repeatability.

  7. Characterization of quinone derived protein adducts and their selective identification using redox cycling based chemiluminescence assay.

    Science.gov (United States)

    Elgawish, Mohamed Saleh; Kishikawa, Naoya; Ohyama, Kaname; Kuroda, Naotaka

    2015-07-17

    The cytotoxic mechanism of many quinones has been correlated to covalent modification of cellular proteins. However, the identification of relevant proteins targets is essential but challenging goals. To better understand the quinones cytotoxic mechanism, human serum albumin (HSA) was incubated in vitro with different concentration of menadione (MQ). In this respect, the initial nucleophilic addition of proteins to quinone converts the conjugates to redox-cycling quinoproteins with altered conformation and secondary structure and extended life span than the short lived, free quinones. The conjugation of MQ with nucleophilic sites likewise, free cysteine as well as ɛ-amino group of lysine residue of HSA has been found to be in concentration dependent manner. The conventional methods for modified proteins identification in complex mixtures are complicated and time consuming. Herein, we describe a highly selective, sensitive, simple, and fast strategy for quinoproteins identification. The suggested strategy exploited the unique redox-cycling capability of quinoproteins in presence of a reductant, dithiothreitol (DTT), to generate reactive oxygen species (ROS) that gave sufficient chemiluminescence (CL) when mixed with luminol. The CL approach is highly selective and sensitive to detect the quinoproteins in ten-fold molar excess of native proteins without adduct enrichment. The approach was also coupled with gel filtration chromatography (GFC) and used to identify adducts in complex mixture of proteins in vitro as well as in rat plasma after MQ administration. Albumin was identified as the main protein in human and rat plasma forming adduct with MQ. Overall, the identification of quinoproteins will encourage further studies of toxicological impact of quinones on human health. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Dissociation and reduction of covalent β-lactoglobulin-quinone adducts by dithiothreitol, tris(2-carboxyethyl)phosphine, or sodium sulfite.

    Science.gov (United States)

    Jongberg, Sisse; Lund, Marianne N; Otte, Jeanette

    2015-06-01

    Covalent protein-phenol adducts, generated by reaction of protein nucleophiles with quinones, have recently attracted increased attention because the interactions change the functionality and physicochemical properties of proteins in biological and food systems. The formation of such covalent adducts between β-lactoglobulin (β-LG) and the quinone of 4-methylcatechol, 4-methylbenzoquinone (4MBQ), and subsequent reduction by dithiothreitol (DTT), tris(2-carboxyethyl)phosphine (TCEP), or sodium sulfite was investigated by mass spectrometry. The results showed that 19.0 ± 8.8% of β-LG reacted with 4MBQ when present in equimolar ratio at 20°C (pH 8.0) to yield the protein-phenol adduct (β-LG-Q). Following treatment with sulfite, DTT, or TCEP, 75, 68, or 36%, respectively, of the formed β-LG-Q adduct dissociated. Different reaction mechanisms were proposed for the reduction of β-LG and β-LG-Q by each of the reducing agents. These results show that on reductive sample preparation for analysis of protein samples, not only are protein polymers formed through oxidative disulfide bonds reduced into the individual protein constituents but also a large part of any protein-phenol adducts present will dissociate and, thus, give a false picture of the level of protein-protein interactions that have occurred in the sample. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Sperm quality and DNA integrity of coke oven workers exposed to polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Jeng, Hueiwang Anna; Pan, Chih-Hong; Chao, Mu-Rong; Chiu, Chien-Chih; Zhou, Guodong; Chou, Chon-Kit; Lin, Wen-Yi

    2016-11-18

    The objective of this study was to assess sperm quality and deoxyribonucleic acid (DNA) integrity of coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) as compared to control subjects. The coke oven workers (N = 52) and administrative staff (N = 35) of a steel plant served as the exposed and control groups, respectively. Exposure to PAHs was assessed by measuring 1-hydroxypyren. Analysis of sperm quality (concentration, motility, vitality, and morphology) was performed simultaneously with sperm DNA integrity analysis, including DNA fragmentation, denaturation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo). A questionnaire was conducted to collect demographic and potential confounding data. The coke oven workers had lower percentages of sperm motility, vitality and normal morphology than the control group, but the difference was not significant. For DNA integrity, the coke oven workers had significantly higher concentrations of bulky DNA adducts and 8-oxo-dGuo than the control subjects (p = 0.009 and p = 0.048, respectively). However, DNA fragmentation percentages did not significantly increase as compared to those in the subjects from the control group (p = 0.232). There was no correlation between sperm quality parameters and DNA integrity indicators. Occupational exposure of the coke oven workers to PAHs was associated with decreased sperm DNA integrity. Int J Occup Med Environ Health 2016;29(6):915-926.

  10. Lead tetraacetate oxidation of the Diels-Alder adduct of 7-dehydrocholestryl acetate with maleic anhydride

    Directory of Open Access Journals (Sweden)

    MIHAILO LJ. MIHAILOVIC

    2000-03-01

    Full Text Available The Diels-Alder adduct (3, obtained by cycloaddition of 7-dehydrocholesteryl acetate (1 and maleic anhydride (2, was heated at ca. 90°C with a large excess of lead tetraacetate in pyridine solution for 5 h. Under these conditions, compound 3 underwent lactonization with the participation of the olefinic D6-double bond to give two isomeric monolactone derivatives, 9 and 10 (in a total yield of ca. 6%, and the bislactone product 11 (in 11.5% yield. The starting material was recovered in 36% yield.

  11. Electron Impact Excitation of C60 Adducts: Flourescence From C60OH and C60H Species

    Science.gov (United States)

    Trajmar, S.; Kanik, I.

    1996-01-01

    An investigation concerning possible visible and UV photon emissions by gas phase C(sub 60) ( and C(sub 70)) samples under electron impact excitation was caried out in the 180-750 nm spectral region. Radiation resembling OH (A (sup 2)pi {leads to}X (sup 2){summation}) emission bands and H Balmer series was observed. Based on our investigations, it is concluded that none of the observed emission was associated with the fullerene molecule itself but with the C(sub 60)OH and C(sub 60)H adducts (which are present in the fullerene samples). We also conclude that in these adducts, simultaneous ionization and excitation take place under electron impact and the excited ionic species (C(sub 60)+OH* and C(sub 60)+H*) decay by radiation which was observed in our experiments. These surprising results reveal an interesting new character of buckyball adducts.

  12. Efficient CO2 capture by tertiary amine-functionalized ionic liquids through Li+-stabilized zwitterionic adduct formation

    Directory of Open Access Journals (Sweden)

    Zhen-Zhen Yang

    2014-08-01

    Full Text Available Highly efficient CO2 absorption was realized through formation of zwitterionic adducts, combining synthetic strategies to ionic liquids (ILs and coordination. The essence of our strategy is to make use of multidentate cation coordination between Li+ and an organic base. Also PEG-functionalized organic bases were employed to enhance the CO2-philicity. The ILs were reacted with CO2 to form the zwitterionic adduct. Coordination effects between various lithium salts and neutral ligands, as well as the CO2 capacity of the chelated ILs obtained were investigated. For example, the CO2 capacity of PEG150MeBu2N increased steadily from 0.10 to 0.66 (mol CO2 absorbed per mol of base through the formation of zwitterionic adducts being stabilized by Li+.

  13. Effects of foot orthoses and valgus bracing on the knee adduction moment and medial joint load during gait.

    Science.gov (United States)

    Shelburne, Kevin B; Torry, Michael R; Steadman, J Richard; Pandy, Marcus G

    2008-07-01

    Lateral shoe wedges and valgus knee braces are designed to decrease the force acting in the medial knee compartment by reducing the external adduction moment applied at the knee. The biomechanical changes introduced by these orthoses can be relatively small. Computer modeling and simulation offers an alternative approach for assessing the biomechanical performance of these devices. A three-dimensional model of the lower-limb was used to calculate muscle, ligament, and joint loading at the knee during gait. A lateral shoe wedge was simulated by moving the center of pressure of the ground reaction force up to 5mm laterally. A valgus knee brace was simulated by applying abduction moments of up to 12 Nm at the knee. Knee adduction moment and medial compartment load decreased linearly with lateral displacement of the center of pressure of the ground reaction force. A 1 mm displacement of the center of pressure decreased the peak knee adduction moment by 2%, while the peak medial compartment load was reduced by 1%. Knee adduction moment and medial compartment force also decreased linearly with valgus moments applied about the knee. A 1 Nm increase in brace moment decreased the peak knee adduction moment by 3%, while the peak medial compartment load was reduced by 1%. Changes in knee joint loading due to lateral shoe wedges and valgus bracing are small and may be difficult to measure by conventional gait analysis methods. The relationships between lateral shift in the center of pressure of the ground force, valgus brace moment, knee adduction moment, and medial joint load can be quantified and explained using computer modeling and simulation. These relationships may serve as a useful guide for evaluating the biomechanical efficacy of a generic wedge insole or knee brace.

  14. Feasibility of vocal fold abduction and adduction assessment using cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Baki, Marina Mat [National University of Malaysia, Faculty of Medicine, Kuala Lumpur (Malaysia); Menys, Alex; Morley, Simon; Beale, Timothy [University College London, Centre for Medical Imaging, London (United Kingdom); Atkinson, David; Punwani, Shonit [University College London, Centre for Medical Imaging, London (United Kingdom); Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Bassett, Paul [University College London, London (United Kingdom); Sandhu, Guri [Charing Cross Hospital, Imperial College Healthcare NHS Trust, London (United Kingdom); Naduvilethil, Georgekutty; Stevenson, Nicola [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Birchall, Martin A. [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); University of California, Davis, Department of Otolaryngology, Davis, CA (United States); University College London, Ear Institute, London (United Kingdom)

    2017-02-15

    Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. (orig.)

  15. Formation of vitisins and anthocyanin-flavanol adducts during red grape drying.

    Science.gov (United States)

    Marquez, Ana; Dueñas, Montserrat; Serratosa, María P; Merida, Julieta

    2012-07-11

    This study evaluated the formation of anthocyanin-derived compounds during the production of sweet red wines from Merlot and Syrah grapes previously chamber-dried under controlled-temperature conditions. The musts from both grape varieties were found to contain pelargonidin-3-glucoside throughout the vinification process. Besides, HPLC-DAD-MS revealed the presence of pyranoanthocyanins in unfermented musts from the raisins. These compounds are adducts resulting from the cycloaddition of pyruvic acid (type A vitisins) and acetaldehyde (type B vitisins) to anthocyanin molecules. The analyses additionally revealed the presence of products of the condensation via a methylmethine bridge between anthocyanins and (epi)catechin, which requires the presence of acetaldehyde. The absence of pyruvic acid, acetaldehyde, and ethanol in the musts from fresh grapes and their presence in those from dried grapes support the idea that these compounds result from enzymatic transformations because the vinification of the musts involves no alcoholic fermentation. The drying process alters the permeability of grape membranes by the lipoxygenase activation effect (LOX), a switch to an anaerobic metabolism and the resulting triggering of the alcohol dehydrogenase enzyme (ADH). The activation of these and several other enzymes confirmed the occurrence of enzymatic transformations and the formation of vitisin A, acetylvitisin A, and the B vitisins of malvidin-3-glucoside, peonidin-3-glucoside, peonidin-3-acetylglucoside, and malvidin-3-acetylglucoside, as well as the adducts Pn-3-glc-methylmethine(epi)catechin, Mv-3-glc-methylmethine(epi) catechin, and Mv-3-acetylmethylmethine(epi)catechin.

  16. Role of scaphoid in the abduction and adduction movements of wrist joint.

    Science.gov (United States)

    Chakraborty, Pitbaran; Majumdar, Sudeshna; Baral, Karabi; Dasgupta, Hasi; Gupta, Indrajit; Ghosh, Santanu

    2011-08-01

    Being a carpal bone scaphoid has an important role in wrist movements. Wrist joint is a synovial modified ellipsoid joint where movements like flexion, extension and adduction, abduction take place around two axes (transverse and anteroposterior). These movements at the wrist joint are associated with considerable range of movements at the midcarpal joint, as same group of muscles act on both of these joints. A study has been done amongst 120 persons at the Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal during the period from 1998-2000 to detect the important movements of scaphoid bone specially during the abduction and adduction of wrist joint (which occur in association with the intercarpal joints) and also to detect whether such movements have any speciality in the population of eastern part of India. It was found in this study that the scaphoid acts as a link bone between the two rows of carpal bones and prevents the buckling of midcarpal joint specially of the capitato-lunate joint interface.

  17. Hydrogen-adduction to open-shell graphene fragments: spectroscopy, thermochemistry and astrochemistry.

    Science.gov (United States)

    O'Connor, Gerard D; Chan, Bun; Sanelli, Julian A; Cergol, Katie M; Dryza, Viktoras; Payne, Richard J; Bieske, Evan J; Radom, Leo; Schmidt, Timothy W

    2017-02-01

    We apply a combination of state-of-the-art experimental and quantum-chemical methods to elucidate the electronic and chemical energetics of hydrogen adduction to a model open-shell graphene fragment. The lowest-energy adduct, 1H-phenalene, is determined to have a bond dissociation energy of 258.1 kJ mol(-1), while other isomers exhibit reduced or in some cases negative bond dissociation energies, the metastable species being bound by the emergence of a conical intersection along the high-symmetry dissociation coordinate. The gas-phase excitation spectrum of 1H-phenalene and its radical cation are recorded using laser spectroscopy coupled to mass-spectrometry. Several electronically excited states of both species are observed, allowing the determination of the excited-state bond dissociation energy. The ionization energy of 1H-phenalene is determined to be 7.449(17) eV, consistent with high-level W1X-2 calculations.

  18. The [3 + 3]-cycloaddition alternative for heterocycle syntheses: catalytically generated metalloenolcarbenes as dipolar adducts.

    Science.gov (United States)

    Xu, Xinfang; Doyle, Michael P

    2014-04-15

    The combination of two or more unsaturated structural units to form cyclic organic compounds is commonly referred to as cycloaddition, and the combination of two unsaturated structural units that forms a six-membered ring is formally either a [5 + 1]-, [4 + 2]-, [2 + 2 + 2]-, or [3 + 3]-cycloaddition. Occurring as concerted or stepwise processes, cycloaddition reactions are among the most useful synthetic constructions in organic chemistry. Of these transformations, the concerted [4 + 2]-cycloaddition, the Diels-Alder reaction, is by far the best known and most widely applied. However, although symmetry disallowed as a concerted process and lacking certifiable examples until recently, stepwise [3 + 3]-cycloadditions offer advantages for the synthesis of a substantial variety of heterocyclic compounds, and they are receiving considerable attention. In this Account, we present the development of stepwise [3 + 3]-cycloaddition reactions from virtual invisibility in the 1990s to a rapidly growing synthetic methodology today, involving organocatalysis or transition metal catalysis. With origins in organometallic or vinyliminium ion chemistry, this area has blossomed into a viable synthetic transformation for the construction of six-membered heterocyclic compounds containing one or more heteroatoms. The development of [3 + 3]-cycloaddition transformations has been achieved through identification of suitable and compatible reactive dipolar adducts and stable dipoles. The reactive dipolar species is an energetic dipolar intermediate that is optimally formed catalytically in the reaction. The stepwise process occurs with the reactive dipolar adduct reacting as an electrophile or as a nucleophile to form the first covalent bond, and this association provides entropic assistance for the construction of the second covalent bond and the overall formal [3 + 3]-cycloaddition. Organocatalysis is well developed for both inter- and intramolecular synthetic transformations, but the

  19. The association between submaximal quadriceps force steadiness and the knee adduction moment during walking in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Sørensen, Tina Juul; Langberg, Henning; Aaboe, Jens

    2011-01-01

    STUDY DESIGN: Cross-sectional study. OBJECTIVES: To investigate the relationship between quadriceps force steadiness and knee adduction moment during walking in patients with knee osteoarthritis (OA). BACKGROUND: Studies have shown that quadriceps force steadiness is impaired in patients with knee......, and knee pain was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale and a visual analog scale. RESULTS: Regression analyses showed that quadriceps force steadiness did not predict the peak knee adduction moment (adjusted R2 = 0.05, P = .41). Inclusion of covariates did...

  20. Rhodium fluorapatite catalyst for the synthesis of trisubstituted olefins via cross coupling of Baylis-Hillman adducts and arylboronic acids.

    Science.gov (United States)

    Kantam, M Lakshmi; Kumar, K B Shiva; Sreedhar, B

    2008-01-04

    Treatment of fluorapatite (prepared by incorporating basic species F(-) in apatite in situ by coprecipitation) with an aqueous solution of RhCl(3) resulted in rhodium-exchanged fluorapatite catalyst (RhFAP), which successfully promoted cross coupling of Baylis-Hillman adducts with arylboronic acids to yield trisubstituted olefins. A variety of arylboronic acids and Baylis-Hillman adducts were converted to the corresponding trisubstituted olefins, demonstrating the versatility of the reaction. The reaction is highly stereoselective. RhFAP was recovered quantitatively by simple filtration and reused with almost consistent activity.

  1. Structure of a DNA glycosylase that unhooks interstrand cross-links

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, Elwood A.; Warren, Garrett M.; Bradley, Noah P.; Eichman, Brandt F. (Vanderbilt)

    2017-04-10

    DNA glycosylases are important editing enzymes that protect genomic stability by excising chemically modified nucleobases that alter normal DNA metabolism. These enzymes have been known only to initiate base excision repair of small adducts by extrusion from the DNA helix. However, recent reports have described both vertebrate and microbial DNA glycosylases capable of unhooking highly toxic interstrand cross-links (ICLs) and bulky minor groove adducts normally recognized by Fanconi anemia and nucleotide excision repair machinery, although the mechanisms of these activities are unknown. Here we report the crystal structure of Streptomyces sahachiroi AlkZ (previously Orf1), a bacterial DNA glycosylase that protects its host by excising ICLs derived from azinomycin B (AZB), a potent antimicrobial and antitumor genotoxin. AlkZ adopts a unique fold in which three tandem winged helix-turn-helix motifs scaffold a positively charged concave surface perfectly shaped for duplex DNA. Through mutational analysis, we identified two glutamine residues and a β-hairpin within this putative DNA-binding cleft that are essential for catalytic activity. Additionally, we present a molecular docking model for how this active site can unhook either or both sides of an AZB ICL, providing a basis for understanding the mechanisms of base excision repair of ICLs. Given the prevalence of this protein fold in pathogenic bacteria, this work also lays the foundation for an emerging role of DNA repair in bacteria-host pathogenesis.

  2. NEW TIN (IV, MX2 AND M’Cl3 (M= Zn, Hg; M’= Pr, Er ADDUCTS AND COMPLEXES OF BIS(AMINOMETHYLBENZENE: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    ASSANE TOURE

    2015-10-01

    Full Text Available The new adducts and complexes obtained have discrete or dimeric structures; in these structures the diamine behaves as a monodentate and hydrogen bonds involved or bidentate ligand. In one rare earth halide adduct the high coordination number (7 proposed is common for this family. When extra intermolecular hydrogen bonds are taken into account, supramolecular architectures may be obtained.

  3. STABILITY OF HEMOGLOBIN AND ALBUMIN ADDUCTS OF BENZENE OXIDE AND 1,4-BENZOQUINONE AFTER ADMINISTRATION OF BENZENE TO F344 RATS

    Science.gov (United States)

    The stability of cysteinyl adducts of benzene oxide (BO) and mono-S-substituted cysteinyl adducts of 1,4-benzoquinone (1,4-BQ) was investigated in both hemoglobin (Hb) and albumin (Alb) following administration of a single oral dose of 400 mg [U-14C/13C6]benzene/kg body weight ...

  4. Acute and sub-acute effects of repetitive kicking on hip adduction torque in injury-free elite youth soccer players

    DEFF Research Database (Denmark)

    Jensen, Jesper; Bandholm, Thomas; Hölmich, Per

    2014-01-01

    Hip adduction strength is important for kicking and acceleration in soccer players. Changes in hip adduction strength may therefore have an effect on soccer players' athletic performance. The purpose of this study was to investigate the acute and sub-acute effects of a kicking drill session on hi...

  5. Methyl bromide causes DNA methylation in rats and mice but fails to induce somatic mutations in lambda lacZ transgenic mice.

    NARCIS (Netherlands)

    Pletsa, V.; Steenwinkel, M.J.; van Delft, J.H.M.; Baan, R.A.; Kyrtopoulos, S.A.

    1999-01-01

    Laboratory of Chemical Carcinogenesis, Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece. Following single or multiple oral treatments of rats or lambda lacZ transgenic mice with methyl bromide, methylated DNA adducts (N7- and/or

  6. Mechanism of DNA-protein cross-linking by chromium.

    Science.gov (United States)

    Macfie, Andrea; Hagan, Elizabeth; Zhitkovich, Anatoly

    2010-02-15

    Hexavalent chromium is a known inducer of DNA-protein cross-links (DPCs) that contribute to repression of inducible genes and genotoxicity of this metal. Lymphocytic DPCs have also shown potential utility as biomarkers of human exposure to Cr(VI). Here, we examined the mechanism of DPC formation by Cr(VI) and the impact of its main cellular reducers. In vitro reactions of Cr(VI) with one-electron reducing thiols (glutathione and cysteine) or two-electron donating ascorbate were all efficient at DPC production, indicating a dispensable role of Cr(V). No Cr(VI) reducer was able to generate DPC in the presence of Cr(III)-chelating EDTA or phosphate. A critical role of Cr(III) in DNA-protein linkages was further confirmed by dissociation of Cr(VI)-induced DPC by phosphate. EDTA was very inefficient in DPC dissociation, indicating its poor suitability for testing of Cr(III)-mediated bridging and reversal of complex DPC. Reactions containing only one Cr-modified component (protein or DNA) showed that Cr(III)-DNA adduction was the initial step in DPC formation. Cross-linking proceeded slowly after the rapid formation of Cr-DNA adducts, indicating that protein conjugation was the rate-limiting step in DPC generation. Experiments with depletion of glutathione and restoration of ascorbate levels in human lung A549 cells showed that high cellular reducing capacity promotes DPC yield. Overall, our data provide evidence for a three-step cross-linking mechanism involving (i) reduction of Cr(VI) to Cr(III), (ii) Cr(III)-DNA binding, and (iii) protein capture by DNA-bound Cr(III) generating protein-Cr(III)-DNA cross-links.

  7. National Status and Trends, Benthic Surveillance Project DNA-Xenobiotic Adducts Data, 1991, National Centers for Coastal Ocean Science

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In order to determine the current status of and to detect any long-term trends in the environmental quality of U.S. nearshore waters, NOAA initiated the National...

  8. Effect of real-time biofeedback on peak knee adduction moment in patients with medial knee osteoarthritis: Is direct feedback effective?

    Science.gov (United States)

    Richards, Rosie E; van den Noort, Josien C; van der Esch, Martin; Booij, Marjolein J; Harlaar, Jaap

    2017-07-13

    Gait modifications can reduce the knee adduction moment, a representation of knee loading. Reduced loading may help to slow progression of medial knee osteoarthritis. We aimed to investigate the response of patients with medial knee osteoarthritis to direct feedback on the knee adduction moment as a method for modifying the gait pattern, before and after training with specific gait modifications. Forty patients with medial knee osteoarthritis underwent 3D gait analysis on an instrumented-treadmill, while receiving real-time feedback on the peak knee adduction moment. Patients were trained with three different modifications; toe-in, wider steps and medial thrust gait. The response to real-time feedback on the knee adduction moment was measured before and after training. To evaluate the short term retention effect, we measured the changes without feedback. We also evaluated the effects on the knee flexion moment and at the hip and ankle joints. With direct feedback on the knee adduction moment, patients were initially unable to reduce the knee adduction moment. After training with specific modifications, peak knee adduction moment was reduced by 14% in response to direct feedback. Without feedback a 9% reduction in peak knee adduction moment was maintained. Hip moments were not increased with modified gait, but small increases in ankle adduction moment and knee flexion moment were observed. Real-time biofeedback directly on the knee adduction moment is a promising option for encouraging gait modifications to reduce knee loading, however only when combined with specific instructions on how to modify the gait. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Aprataxin resolves adenylated RNA-DNA junctions to maintain genome integrity

    Science.gov (United States)

    Tumbale, Percy; Williams, Jessica S.; Schellenberg, Matthew J.; Kunkel, Thomas A.; Williams, R. Scott

    2014-01-01

    Faithful maintenance and propagation of eukaryotic genomes is ensured by three-step DNA ligation reactions employed by ATP-dependent DNA ligases1,2. Paradoxically, when DNA ligases encounter nicked DNA structures with abnormal DNA termini, DNA ligase catalytic activity can generate and/or exacerbate DNA damage through abortive ligation that produces chemically adducted, toxic 5′-adenylated (5′-AMP) DNA lesions3–6 (Fig. 1a). Aprataxin (Aptx) reverses DNA-adenylation but the context for deadenylation repair is unclear. Here we examine the importance of Aptx to RNaseH2-dependent excision repair (RER) of a lesion that is very frequently introduced into DNA, a ribonucleotide. We show that ligases generate adenylated 5′-ends containing a ribose characteristic of RNaseH2 incision. Aptx efficiently repairs adenylated RNA-DNA, and acting in an RNA-DNA damage response (RDDR), promotes cellular survival and prevents S-phase checkpoint activation in budding yeast undergoing RER. Structure-function studies of human Aptx/RNA-DNA/AMP/Zn complexes define a mechanism for detecting and reversing adenylation at RNA-DNA junctions. This involves A-form RNA-binding, proper protein folding and conformational changes, all of which are impacted by heritable APTX mutations in Ataxia with Oculomotor Apraxia 1 (AOA1). Together, these results suggest that accumulation of adenylated RNA-DNA may contribute to neurological disease. PMID:24362567

  10. Mitochondrial DNA.

    Science.gov (United States)

    Wright, Russell G.; Bottino, Paul J.

    1986-01-01

    Provides background information for teachers on mitochondrial DNA, pointing out that it may have once been a free-living organism. Includes a ready-to-duplicate exercise titled "Using Microchondrial DNA to Measure Evolutionary Distance." (JN)

  11. ReProComet: a new in vitro method to assess DNA damage in mammalian sperm.

    Science.gov (United States)

    Cordelli, Eugenia; Fresegna, Anna Maria; D'Alessio, Alessia; Eleuteri, Patrizia; Spanò, Marcello; Pacchierotti, Francesca; Villani, Paola

    2007-10-01

    The increasing request of chemical safety assessment demands for the validation of alternative methods to reduce the resort to animal experimentation. Methods that evaluate reproductive toxicity are among those requiring the largest use of animals. Presently, no validated in vitro alternative exists for the assessment of reproductive toxicity. Mammalian sperm are sensitive targets of DNA-reactive chemicals, which form premutagenic adducts. Here, we propose a new method based on comet assay to detect DNA damage induced by potential germ cell mutagens in bull sperm available from assisted reproduction practices. In somatic cells, chemical-induced adducts can be revealed by comet assay that detects DNA breaks produced during adduct repair. Mature sperm, however, are devoid of repair enzymes, and adducts are processed only after fertilization. For this reason, comet assay is not sensitive to detect DNA lesions induced in sperm by most chemicals. To overcome such limitation, we developed a modified comet assay based on the addition of a protein extract from HeLa cells to agarose-embedded sperm on microscopic slides. To test the method, sperm were treated in vitro with methyl methanesulfonate (MMS) or melphalan (MLP) and comet assay was conducted both with and without protein supplementation. No effect of MMS or MLP was detected without protein supplementation; on the contrary, a clear-cut dose-dependent effect was measured after addition of the cell extract. These results represent a proof of concept of a novel in vitro mutagenicity test on sperm that could offer a promising approach to complement previously validated in vivo germ cell genotoxicity assays.

  12. Effect of base sequence on the DNA cross-linking properties of pyrrolobenzodiazepine (PBD) dimers.

    Science.gov (United States)

    Rahman, Khondaker M; James, Colin H; Thurston, David E

    2011-07-01

    Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) dimers are synthetic sequence-selective DNA minor-groove cross-linking agents that possess two electrophilic imine moieties (or their equivalent) capable of forming covalent aminal linkages with guanine C2-NH(2) functionalities. The PBD dimer SJG-136, which has a C8-O-(CH(2))(3)-O-C8'' central linker joining the two PBD moieties, is currently undergoing phase II clinical trials and current research is focused on developing analogues of SJG-136 with different linker lengths and substitution patterns. Using a reversed-phase ion pair HPLC/MS method to evaluate interaction with oligonucleotides of varying length and sequence, we recently reported (JACS, 2009, 131, 13 756) that SJG-136 can form three different types of adducts: inter- and intrastrand cross-linked adducts, and mono-alkylated adducts. These studies have now been extended to include PBD dimers with a longer central linker (C8-O-(CH(2))(5)-O-C8'), demonstrating that the type and distribution of adducts appear to depend on (i) the length of the C8/C8'-linker connecting the two PBD units, (ii) the positioning of the two reactive guanine bases on the same or opposite strands, and (iii) their separation (i.e. the number of base pairs, usually ATs, between them). Based on these data, a set of rules are emerging that can be used to predict the DNA-interaction behaviour of a PBD dimer of particular C8-C8' linker length towards a given DNA sequence. These observations suggest that it may be possible to design PBD dimers to target specific DNA sequences.

  13. Sorocenols G and H, Anti-MRSA Oxygen Heterocyclic Diels-Alder-type Adducts from Sorocea muriculata Roots

    Science.gov (United States)

    Bioassay-guided fractionation of a root extract of Sorocea muriculata led to the isolation and identification of two new oxygen heterocyclic Diels-Alder-type adducts, sorocenols G (1) and H (2), along with lupeol-3-(3'R-hydroxytetradecanoate) and oxyresveratrol. The structures of 1 and 2 were eluci...

  14. Measurement of HNE-protein adducts in human plasma and serum by ELISA-Comparison of two primary antibodies.

    Science.gov (United States)

    Weber, Daniela; Milkovic, Lidija; Bennett, Stuart J; Griffiths, Helen R; Zarkovic, Neven; Grune, Tilman

    2013-01-01

    There is increasing evidence that non-enzymatic post-translational protein modifications might play key roles in various diseases. These protein modifications can be caused by free radicals generated during oxidative stress or by their products generated during lipid peroxidation. 4-Hydroxynonenal (HNE), a major biomarker of oxidative stress and lipid peroxidation, has been recognized as important molecule in pathology as well as in physiology of living organisms. Therefore, its detection and quantification can be considered as valuable tool for evaluating various pathophysiological conditions. The HNE-protein adduct ELISA is a method to detect HNE bound to proteins, which is considered as the most likely form of HNE occurrence in living systems. Since the earlier described ELISA has been validated for cell lysates and the antibody used for detection of HNE-protein adducts is non-commercial, the aim of this work was to adapt the ELISA to a commercial antibody and to apply it in the analysis of human plasma samples. AFTER MODIFICATION AND VALIDATION OF THE PROTOCOL FOR BOTH ANTIBODIES, SAMPLES OF TWO GROUPS WERE ANALYZED: apparently healthy obese (n=62) and non-obese controls (n=15). Although the detected absolute values of HNE-protein adducts were different, depending on the antibody used, both ELISA methods showed significantly higher values of HNE-protein adducts in the obese group.

  15. Fast Fourier Transform IR Characterization of Epoxy GY Systems Crosslinked with Aliphatic and Cycloaliphatic EH Polyamine Adducts

    Science.gov (United States)

    Nikolic, Goran; Zlatkovic, Sasa; Cakic, Milorad; Cakic, Suzana; Lacnjevac, Caslav; Rajic, Zoran

    2010-01-01

    The use of fast FT-IR spectroscopy as a sensitive method to estimate a change of the crosslinking kinetics of epoxy resin with polyamine adducts is described in this study. A new epoxy formulation based on the use of polyamine adducts as the hardeners was analyzed. Crosslinking reactions of the different stoichiometric mixtures of the unmodified GY250 epoxy resin with the aliphatic EH606 and the cycloaliphatic EH637 polyamine adducts were studied using mid FT-IR spectroscopic techniques. As the crosslinking proceeded, the primary amine groups in polyamine adduct are converted to secondary and the tertiary amines. The decrease in the IR band intensity of epoxy groups at about 915 cm−1, as well as at about 3,056 cm−1, was observed due to process. Mid IR spectral analysis was used to calculate the content of the epoxy groups as a function of crosslinking time and the crosslinking degree of resin. The amount of all the epoxy species was estimated from IR spectra to changes during the crosslinking kinetics of epichlorhydrin. PMID:22315562

  16. Hydrolyzable hemoglobin adducts of polyfunctional monocyclic N-substituted arenes as dosimeters of exposure and markers of metabolism.

    Science.gov (United States)

    Zwirner-Baier, I; Kordowich, F J; Neumann, H G

    1994-01-01

    Hemoglobin adducts of 10 polyfunctional amino- and nitro-substituted benzenes and toluenes were analyzed: 2,4,6-trinitrotoluene, 2,4- and 2,6-dinitrotoluene, 2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene, 2,4- and 2,6-diaminotoluene, 1,3-dinitrobenzene, 1-amino-3-nitrobenzene, and 1,3-diaminobenzene. A single dose (0.5 mmole/kg) of the test compounds was administered to female Wistar rats by gavage, and blood extracted and hemoglobin prepared after 24 hr. One or more cleavage products could be obtained in each case by hydrolyzing hemoglobin (Hb). Hemoglobin binding indices (HBI: binding [mmole/mole Hb]/dose [mmole/kg]) and the ratios of hydrolyzable adducts were determined. The HBI ranged between < 0.02 and 69.0. The results indicate the in vivo formation of several, covalently bound, hydrolyzable hemoglobin adducts. Conclusions on prevailing metabolic pathways can be drawn. Total binding of several compounds seems sufficient for biomonitoring of human blood samples. These chemicals are considered representative for environmental contamination with explosives of this type, and we propose their Hb adducts be used as dosimeters for human exposure to these suspected carcinogens. PMID:7889857

  17. The effect of the trolox equivalent antioxidant capacity (TEAC) in plasma on the formation of 4-aminobiphenylhaemoglobin adducts in smokers.

    Science.gov (United States)

    Dallinga, Jan W; Haenen, Guido R M M; Bast, Aalt; Van Schooten, Frederik-Jan

    2002-01-01

    Smokers are exposed to a number of carcinogenic compounds including aromatic amines such as 4-aminobiphenyl. Antioxidants are thought to be involved in the defence against the damaging effect of such carcinogens. Recently it has been shown that plasma antioxidant status in smokers is diminished compared with non-smokers. In this study we investigated in 40 smokers whether the trolox equivalent antioxidant capacity (TEAC) in plasma could be quantitatively related to exposure to cigarette smoke. The biomarkers 4-aminobiphenylhaemoglobin (4-ABP-Hb) adduct and cotinine were determined as indices of cigarette smoke exposure. A correlation between 4-ABP-Hb adduct levels and plasma cotinine levels was found for the whole population studied, who smoked 4-70 cigarettes per day (n = 40, r(2) = 0.12, p = 0.03). A significant inverse relationship was found between TEAC and 4-ABP-Hb levels (n = 40, r(2) = 0.17, p = 0.008). Multiple regression analysis showed a strong relationship between 4-ABP-Hb levels and plasma TEAC and cotinine levels (n = 40, r(2) =0.29, p = 0.002). These findings provide strong evidence that the 4- ABP-Hb adduct represents a valuable biomarker of (internal) exposure to tobacco smoke, and also that the formation of this marker is dependent on the plasma antioxidant status. The multiple regression analysis results show that the measure of effect (4-ABP-Hb adduct formation) is largely determined by dose (cotinine) and protection (TEAC).

  18. The lack of mutagenic properties of patulin and patulin adducts formed with cysteine in Salmonella test systems.

    Science.gov (United States)

    von Wright, A; Lindroth, S

    1978-11-01

    The mutagenic properties of patulin and the patulin adducts formed with cysteine were tested with histidine auxotroph Salmonella typhimurium strains as indicator organisms. The tests were performed by microsomal activation and host-mediated assay. Neither patulin nor patulin--cysteine reaction mixture was mutagenic in these test systems.

  19. Structural aspects, thermal behavior, and stability of a self-assembled supramolecular polymer derived from flunixin-meglumine supramolecular adducts

    Energy Technology Data Exchange (ETDEWEB)

    Cassimiro, Douglas L.; Kobelnik, Marcelo [Institute of Chemistry, Paulista State University, Av. Prof. Francisco Degni, s/n, 14800-900 Araraquara, Sao Paulo (Brazil); Ribeiro, Clovis A., E-mail: ribeiroc@iq.unesp.br [Institute of Chemistry, Paulista State University, Av. Prof. Francisco Degni, s/n, 14800-900 Araraquara, Sao Paulo (Brazil); Crespi, Marisa S.; Boralle, Nivaldo [Institute of Chemistry, Paulista State University, Av. Prof. Francisco Degni, s/n, 14800-900 Araraquara, Sao Paulo (Brazil)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer The thermal behavior of flunixin-meglumine, a potent NSAID, was investigated. Black-Right-Pointing-Pointer This supramolecular adduct self-assembled resulting in a polymer-like material. Black-Right-Pointing-Pointer The supramolecular polymer showed a high molecular weight around 290 {+-} 88 MDa. Black-Right-Pointing-Pointer NMR and FT-IR showed that hydrogen bonding can be responsible for the self-assembly. Black-Right-Pointing-Pointer The stability of the supramolecular polymer was also studied and presented here. - Abstract: Flunixin-meglumine, a potent non-steroidal anti-inflammatory drug (NSAID) and a cyclo-oxygenase inhibitor for Veterinary use, is a hydrogen-bonded supramolecular adduct. Two monotropically related crystalline modifications (Forms I and II) were observed for a flunixin-meglumine sample. During the melt of form I, flunixin-meglumine adducts self-assembled by hydrogen bonds involving the hydroxyl groups from meglumine, resulting in an amorphous rigid glassy supramolecular polymer, which showed a high molecular weight around 290 {+-} 88 MDa and a glass transition around 49.5 Degree-Sign C. Both the adduct and the resulting supramolecular polymer were characterized by differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (NMR), Fourier transform-infrared spectroscopy (FT-IR), and weight-average molecular weight determination by light scattering. The chemical stability and morphological changes of the depolymerization process were also investigated for the supramolecular polymer, by DSC and scanning electron microscopy (SEM), respectively.

  20. Modeling DNA

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Deoxyribonucleic acid (DNA) is life's most amazing molecule. It carries the genetic instructions that almost every organism needs to develop and reproduce. In the human genome alone, there are some three billion DNA base pairs. The most difficult part of teaching DNA structure, however, may be getting students to visualize something as small as a…

  1. Plasma and liver acetaminophen-protein adduct levels in mice after acetaminophen treatment: Dose–response, mechanisms, and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    McGill, Mitchell R.; Lebofsky, Margitta [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Norris, Hye-Ryun K.; Slawson, Matthew H. [Center for Human Toxicology, University of Utah, Salt Lake City, UT (United States); Bajt, Mary Lynn; Xie, Yuchao; Williams, C. David [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Wilkins, Diana G.; Rollins, Douglas E. [Center for Human Toxicology, University of Utah, Salt Lake City, UT (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2013-06-15

    At therapeutic doses, acetaminophen (APAP) is a safe and effective analgesic. However, overdose of APAP is the principal cause of acute liver failure in the West. Binding of the reactive metabolite of APAP (NAPQI) to proteins is thought to be the initiating event in the mechanism of hepatotoxicity. Early work suggested that APAP-protein binding could not occur without glutathione (GSH) depletion, and likely only at toxic doses. Moreover, it was found that protein-derived APAP-cysteine could only be detected in serum after the onset of liver injury. On this basis, it was recently proposed that serum APAP-cysteine could be used as diagnostic marker of APAP overdose. However, comprehensive dose–response and time course studies have not yet been done. Furthermore, the effects of co-morbidities on this parameter have not been investigated. We treated groups of mice with APAP at multiple doses and measured liver GSH and both liver and plasma APAP-protein adducts at various timepoints. Our results show that protein binding can occur without much loss of GSH. Importantly, the data confirm earlier work that showed that protein-derived APAP-cysteine can appear in plasma without liver injury. Experiments performed in vitro suggest that this may involve multiple mechanisms, including secretion of adducted proteins and diffusion of NAPQI directly into plasma. Induction of liver necrosis through ischemia–reperfusion significantly increased the plasma concentration of protein-derived APAP-cysteine after a subtoxic dose of APAP. While our data generally support the measurement of serum APAP-protein adducts in the clinic, caution is suggested in the interpretation of this parameter. - Highlights: • Extensive GSH depletion is not required for APAP-protein binding in the liver. • APAP-protein adducts appear in plasma at subtoxic doses. • Proteins are adducted in the cell and secreted out. • Coincidental liver injury increases plasma APAP-protein adducts at subtoxic doses

  2. Crystal structure of the bis(cyclohexylammonium succinate succinic acid salt adduct

    Directory of Open Access Journals (Sweden)

    Modou Sarr

    2015-08-01

    Full Text Available The crystal structure of the title salt adduct, 2C6H14N+·C4H4O42−·C4H6O4, consists of two cyclohexylammonium cations, one succcinate dianion and one neutral succinic acid molecule. Succinate dianions and succinic acid molecules are self-assembled head-to-tail through O—H...O hydrogen bonds and adopt a syn–syn configuration, leading to a strand-like arrangement along [101]. The cyclohexylammonium cations have a chair conformation and act as multidentate hydrogen-bond donors linking adjacent strands through intermolecular N—H...O interactions to both the succinate and the succinic acid components. This results in two-dimensional supramolecular layered structures lying parallel to (010.

  3. Structure of the Covalent Adduct Formed Between Mycobacterium tuberculosis beta-Lactamase and Clavulanate

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay,L.; Hugonnet, J.; Blanchard, J.

    2008-01-01

    The intrinsic resistance of Mycobacterium tuberculosis to the {beta}-lactam class of antibiotics arises from a chromosomally encoded, extended spectrum, class A {beta}-lactamase, BlaC. Herein, we report the X-ray crystallographic structure of BlaC inhibited with clavulanate at a resolution of 1.7 Angstroms with an R-factor value of 0.180 and R-free value of 0.212 for the m/z +154 clavulanate-derived fragment observed in the active site. Structural evidence reveals the presence of hydrogen bonds to the C1 carbonyl along with a coplanar arrangement of C1, C2, C3, and N4, which favors enolization to generate a trans-a, {beta}-eneamine, stabilizing the +154 adduct from hydrolysis. The irreversible inhibition of BlaC suggests that treatment of M. tuberculosis with a combination of a {beta}-lactam antibiotic and clavulanate may lead to rapid bactericidal activity.

  4. Synthesis and Spectral Characterization of Novel Spiroindan-1,3-Dione: A Diels Alder Adduct

    Directory of Open Access Journals (Sweden)

    N. D. Zargar

    2013-01-01

    Full Text Available DMSO/Ac2O reagent converts 1,3-indandione (1 to an unusual dimer 1H,1′H-2,2′-biindene-1,1′,3,3′(2H,2′H tetrone and a dimeric condensation product along with an ylide (1a at room temperature. This reagent also brings about oxidation of secondary alcohols to corresponding ketones, methyl thiomethylation, and N-hydroxymethylation in phthalimide and converts 4-hydroxycoumarins and dicoumarol to different oxidative and degradation products under varying conditions. However, when 1,3-indandione was refluxed with DMSO/Ac2O reagent at 150°C, it afforded a novel compound, 2-spiroindan 1,3-dione (2, a Diels Alder Adduct, analogous to (3 obtained upon treatment of 1,3-indandione with formaldehyde in presence of primary amines.

  5. Metal-isonitrile adducts for preparing radionuclide complexes for labelling and imaging agents

    Science.gov (United States)

    Jones, Alun G.; Davison, Alan; Abrams, Michael J.

    1987-01-01

    A method for preparing a coordination complex of an isonitrile ligand and radionuclide such as Tc, Ru, Co, Pt, Fe, Os, Ir, W, Re, Cr, Mo, Mn, Ni, Rh, Pd, Nb and Ta is disclosed. The method comprises preparing a soluble metal adduct of said isonitrile ligand by admixing said ligand with a salt of a displaceable metal having a complete d-electron shell selected from the group consisting of Zn, Ga, Cd, In, Sn, Hg, Tl, Pb and Bi to form a soluble metal-isonitrile salt, and admixing said metal isonitrile salt with a salt comprising said radioactive metal in a suitable solvent to displace said displaceable metal with the radioactive metal thereby forming said coordination. The complex is useful as a diagnostic agent for labelling liposomes or vesicles, and selected living cells containing lipid membranes, such as blood clots, myocardial tissue, gall bladder tissue, etc.

  6. Judgment of pure fermented soy sauce by fluorescence resonance energy transfer of OPA-tryptophan adduct.

    Science.gov (United States)

    Gao, You-Syuan; Hsieh, Bo-Chuan; Cheng, Tzong-Jih; Chen, Richie L C

    2015-07-01

    Tryptophan was detected with a flow-injection manifold after reacting with mM order of fluorogenic o-phthalaldehyde (OPA)/thiol reagent (pH 10.0) in the carrier stream (0.63 mL/min). Based on the intra-molecular fluorescence resonance energy transfer of OPA-tryptophan adduct, the difference in fluorescence intensity obtained at 280 and 300 nm excitation was used to detect tryptophan content with satisfactory precision (CVtryptophan will decompose during manufacturing non-fermented soy sauce by acid-hydrolysis procedure, the method was used to discriminate pure fermented soy sauces, adulterated soy sauces and chemical soy sauces in less than 5 min. The ratio of tryptophan to total amino acid content served as the index for the judgment, and the results were validated by capillary electrophoresis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Recyclable thermosetting thermal pad using silicone-based polyurethane crosslinked by Diels-Alder adduct

    Science.gov (United States)

    Kim, Jong-Woong; Lee, Da Hee; Jeon, Hee-Jeong; Jang, Sung Il; Cho, Hyun Min; Kim, Youngmin

    2018-01-01

    The recyclable silicone-based thermoset was successfully synthesized by making use of a Diels-Alder (DA) adduct as a cross-linker. The incorporation of the furan-tethered diol 1 into the polymer backbones realized the crosslinking of polymers via the DA reaction. The thermosetting polymer was dissolved in DMF after the retro DA reaction which was monitored by 1H NMR spectroscopy. Due to the retro DA reaction, polymer showed the mendable behavior when it was scratched followed by being heated. This polymer was mixed with alumina powders to fabricate the thermal pad. The thermal resistance of this pad was measured to be 0.48 K/W by a thermal transient test. The thermosetting composite was recycled via the retro DA reaction. The thermal resistance of the recycled one was similar to that of the original one.

  8. A Tri-O-Bridged Diels-Alder Adduct from Cortex Mori Radicis

    Directory of Open Access Journals (Sweden)

    An-Qi Lu

    2018-01-01

    Full Text Available Sanggenon X, an unusual tri-O-bridged Diels-Alder adduct, was isolated from Cortex Mori Radicis. Its structure was established by spectroscopic analysis, including NMR and HR-MS (High Resolution Mass Spectrometry. Sanggenon X contained three O-bridged rings, where the oxygenated bridgeheads were all quaternary carbons. Chemical methylation was carried out to deduce the linkages of the three O-bridges. The absolute configuration was determined by calculating the ECD (Electronic Circular Dichroism using the TDDFT (Time-Dependent Density Functional Theory method. Sanggenon X showed significant antioxidant activity against Fe2+-Cys-induced lipid peroxidation in rat liver microsomes, and was as effective as the positive control, curcumin.

  9. A Tri-O-Bridged Diels-Alder Adduct from Cortex Mori Radicis.

    Science.gov (United States)

    Lu, An-Qi; Chen, Ming-Hua; Gao, Jie; Wang, Lu; Yang, Han-Yu; Li, Lan; Zhang, Bo; He, Hao-Ke; Wang, Su-Juan

    2018-01-09

    Sanggenon X, an unusual tri-O-bridged Diels-Alder adduct, was isolated from Cortex Mori Radicis. Its structure was established by spectroscopic analysis, including NMR and HR-MS (High Resolution Mass Spectrometry). Sanggenon X contained three O-bridged rings, where the oxygenated bridgeheads were all quaternary carbons. Chemical methylation was carried out to deduce the linkages of the three O-bridges. The absolute configuration was determined by calculating the ECD (Electronic Circular Dichroism) using the TDDFT (Time-Dependent Density Functional Theory) method. Sanggenon X showed significant antioxidant activity against Fe2+-Cys-induced lipid peroxidation in rat liver microsomes, and was as effective as the positive control, curcumin.

  10. Photoinduced formation mechanism of the thymine-thymine (6-4) adduct.

    Science.gov (United States)

    Giussani, Angelo; Serrano-Andrés, Luis; Merchán, Manuela; Roca-Sanjuán, Daniel; Garavelli, Marco

    2013-02-21

    The photoinduced mechanism leading to the formation of the thymine-thymine (6-4) photolesion has been studied by using the CASPT2//CASSCF approach over a dinucleotide model in vacuo. Following light absorption, localization of the excitation on a single thymine leads to fast singlet-triplet crossing that populates the triplet (3)(nπ*) state of thymine. This state, displaying an elongated C(4)═O bond, triggers (6-4) dimer formation by reaction with the C(5)═C(6) double bond of the adjacent thymine, followed by a second intersystem crossing, which acts as a gate between the excited state of the reactant and the ground state of the photoproduct. The requirement of localized excitation on just one thymine, whose main decay channel (by radiationless repopulation of its ground state) is nonphotochemical, can rationalize the experimentally observed low quantum yield of formation for the thymine-thymine (6-4) adduct.

  11. RNA polymerase II is released from the DNA template during transcription-coupled repair in mammalian cells.

    Science.gov (United States)

    Chiou, Yi-Ying; Hu, Jinchuan; Sancar, Aziz; Selby, Christopher P

    2018-02-16

    In mammalian cells, bulky DNA adducts located in the template but not the coding strand of genes block elongation by RNA polymerase II (RNAPII). The blocked RNAPII targets these transcription-blocking adducts to undergo more rapid excision repair than adducts located elsewhere in the genome. In excision repair, coupled incisions are made in the damaged DNA strand on both sides of the adduct. The fate of RNAPII in the course of this transcription-coupled repair (TCR) pathway is unclear. To address the fate of RNAPII, we used methods that control transcription to initiate a discrete "wave" of elongation complexes. Analyzing genome-wide transcription and repair by next-generation sequencing, we identified locations of elongation complexes and transcription-repair coupling events in genes throughout the genome. Using UV-exposed human skin fibroblasts, we found that, at the dose used, a single wave of elongation complexes was blocked within the first 25 kb of genes. TCR occurred where the elongation complexes were blocked, and repair was associated with the dissociation of these complexes. These results indicate that individual elongation complexes do not engage in multiple rounds of TCR with successive lesions. Our results are consistent with a model in which RNAPII is dissociated after the dual incision of the transcription-blocking lesion, perhaps by Cockayne syndrome group B translocase, or during the synthesis of a repair patch. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Albumin adducts and urinary metabolites resulting from occupational exposure to 1,5-naphthalene diisocyanate

    Directory of Open Access Journals (Sweden)

    Ovnair Sepai

    2017-08-01

    Full Text Available Objectives: 1,5-Naphthalene diisocyanate (NDI is used in the plastic industry as a curing agent. 1,5-Naphthalene diisocyanate is classified as a sensitizing agent. The objective of this study has been to develop biomonitoring methods for the evaluation of exposure to NDI. Material and Methods: We obtained blood and urine samples from a group of 20 male workers exposed to NDI. The workers answered a questionnaire about their exposure history, job description, the number of years with the company and the time spent working with NDI over the 10 days of the study. Total plasma, albumin, and urine were analyzed for the presence of 1,5-naphthalenediamine (NDA after acid hydrolysis using gas chromatography-mass spectrometry (GC-MS. Results: 1,5-Naphthalenediamine was found in about 60% of the samples obtained from the workers. 1,5-Naphthalenediamine was obtained after acid hydrolysis of plasma, albumin, and urine at levels up to 1.5 pmol NDA/mg of plasma proteins, 1.15 pmol NDA/mg of albumin, and 55.3 pmol NDA/ml of urine, respectively. Conclusions: 1,5-Naphthalenediamine found in urine correlates best with the plasma levels (r = 0.91, p < 0.01. The albumin-adduct levels did not correlate with the NDI-specific immunoglobulin E (IgE or total IgE present in the workers. The adduct and metabolite levels correlate with the air levels of NDI. Int J Occup Med Environ Health 2017;30(4:579–591

  13. Albumin adducts and urinary metabolites resulting from occupational exposure to 1,5-naphthalene diisocyanate.

    Science.gov (United States)

    Sepai, Ovnair; Sabbioni, Gabriele

    2017-06-19

    1,5-Naphthalene diisocyanate (NDI) is used in the plastic industry as a curing agent. 1,5-Naphthalene diisocyanate is classified as a sensitizing agent. The objective of this study has been to develop biomonitoring methods for the evaluation of exposure to NDI. We obtained blood and urine samples from a group of 20 male workers exposed to NDI. The workers answered a questionnaire about their exposure history, job description, the number of years with the company and the time spent working with NDI over the 10 days of the study. Total plasma, albumin, and urine were analyzed for the presence of 1,5-naphthalenediamine (NDA) after acid hydrolysis using gas chromatography-mass spectrometry (GC-MS). 1,5-Naphthalenediamine was found in about 60% of the samples obtained from the workers. 1,5-Naphthalenediamine was obtained after acid hydrolysis of plasma, albumin, and urine at levels up to 1.5 pmol NDA/mg of plasma proteins, 1.15 pmol NDA/mg of albumin, and 55.3 pmol NDA/ml of urine, respectively. 1,5-Naphthalenediamine found in urine correlates best with the plasma levels (r = 0.91, p < 0.01). The albumin-adduct levels did not correlate with the NDI-specific immunoglobulin E (IgE) or total IgE present in the workers. The adduct and metabolite levels correlate with the air levels of NDI. Int J Occup Med Environ Health 2017;30(4):579-591.

  14. Influence of chlorine substitution on the hydrolytic stability of biaryl ether nucleoside adducts produced by phenolic toxins.

    Science.gov (United States)

    Kuska, Michael S; Majdi Yazdi, Mohadeseh; Witham, Aaron A; Dahlmann, Heidi A; Sturla, Shana J; Wetmore, Stacey D; Manderville, Richard A

    2013-07-19

    A kinetic study is reported for the acid-catalyzed hydrolysis of oxygen (O)-linked biaryl ether 8-2'-deoxyguanosine (dG) adducts produced by phenolic toxins following metabolism into phenoxyl radical intermediates. Strikingly, the reaction rate of hydrolysis at pH 1 decreases as electron-withdrawing chlorine (Cl) substituents are added to the phenoxyl ring. The Hammett plot for hydrolysis at pH 1 shows a linear negative slope with ρX = -0.65, implying that increased Cl-substitution diminishes the rate of hydrolysis by lowering N(7) basicity. Spectrophotometric titration provided an N(7)H(+) pKa value of 1.1 for the unsubstituted adduct 8-phenoxy-dG (Ph-O-dG). Model pyridine compounds suggest N(7)H(+) pKa values of 0.92 and 0.37 for 4-Cl-Ph-O-dG and 2,6-dichloro-Ph-O-dG (DCP-O-dG), respectively. Density functional theory (DFT) calculations also highlight the ability of the 8-phenoxy substituent to lower N(7) basicity and predict a preference for N(3)-protonation for highly chlorinated O-linked 8-dG adducts in water. The calculations also provide a rationale for the hydrolytic reactivity of O-linked 8-dG adducts in the gas-phase, as determined using electrospray mass spectrometry (ESI-MS). The inclusion of our data now establishes that the order of hydrolytic reactivity at neutral pH for bulky 8-dG adducts is N-linked > C-linked > O-linked, which correlates with their relative ease of N(7)-protonation.

  15. DNA damage in lung after oral exposure to diesel exhaust particles in Big Blue (R) rats

    DEFF Research Database (Denmark)

    Müller, Anne Kirstine; Farombi, E.O.; Møller, P.

    2004-01-01

    . Lung tissue is a target organ for DEP induced cancer following inhalation. Recent studies have provided evidence that the lung is also a target organ for DNA damage and cancer after oral exposure to other complex mixtures of PAHs. The genotoxic effect of oral administration of DEP was investigated......Several chemical mutagens and carcinogens, including polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs, are adsorbed to the surface of diesel exhaust particles (DEP). DEP can induce formation of reactive oxygen species and cause oxidative DNA damage as well as bulky carcinogen DNA adducts......, in terms of markers of DNA damage, mutations and repair, in the lung of Big Blue(R) rats fed a diet with 0, 0.2, 0.8, 2, 8, 20 or 80 mg DEP/kg feed for 21 days. There was no significant increase in the mutation frequency in the cII gene. However, an increase of DNA damage measured as DNA strand breaks...

  16. GENETIC AND MOLECULAR ANALYSIS OF DNA DAMAGE REPAIR AND TOLERANCE PATHWAYS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND, B.M.

    2001-07-26

    Radiation can damage cellular components, including DNA. Organisms have developed a panoply of means of dealing with DNA damage. Some repair paths have rather narrow substrate specificity (e.g. photolyases), which act on specific pyrimidine photoproducts in a specific type (e.g., DNA) and conformation (double-stranded B conformation) of nucleic acid. Others, for example, nucleotide excision repair, deal with larger classes of damages, in this case bulky adducts in DNA. A detailed discussion of DNA repair mechanisms is beyond the scope of this article, but one can be found in the excellent book of Friedberg et al. [1] for further detail. However, some DNA damages and paths for repair of those damages important for photobiology will be outlined below as a basis for the specific examples of genetic and molecular analysis that will be presented below.

  17. Aprataxin resolves adenylated RNA–DNA junctions to maintain genome integrity

    Energy Technology Data Exchange (ETDEWEB)

    Tumbale, Percy [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States). Lab. of Structural Biology; Williams, Jessica S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States). Lab. of Structural Biology; Schellenberg, Matthew J. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States). Lab. of Structural Biology; Kunkel, Thomas A. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States). Lab. of Structural Biology and Lab. of Molecular Genetics; Williams, R. Scott [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States). Lab. of Structural Biology and Lab. Molecular Genetics

    2013-12-22

    Faithful maintenance and propagation of eukaryotic genomes is ensured by three-step DNA ligation reactions used by ATP-dependent DNA ligases. Paradoxically, when DNA ligases encounter nicked DNA structures with abnormal DNA termini, DNA ligase catalytic activity can generate and/or exacerbate DNA damage through abortive ligation that produces chemically adducted, toxic 5'-adenylated (5'-AMP) DNA lesions. Aprataxin (APTX) reverses DNA adenylation but the context for deadenylation repair is unclear. Here we examine the importance of APTX to RNase-H2-dependent excision repair (RER) of a lesion that is very frequently introduced into DNA, a ribonucleotide. We show that ligases generate adenylated 5' ends containing a ribose characteristic of RNase H2 incision. APTX efficiently repairs adenylated RNA–DNA, and acting in an RNA–DNA damage response (RDDR), promotes cellular survival and prevents S-phase checkpoint activation in budding yeast undergoing RER. Structure–function studies of human APTX–RNA–DNA–AMP–Zn complexes define a mechanism for detecting and reversing adenylation at RNA–DNA junctions. This involves A-form RNA binding, proper protein folding and conformational changes, all of which are affected by heritable APTX mutations in ataxia with oculomotor apraxia 1. Together, these results indicate that accumulation of adenylated RNA–DNA may contribute to neurological disease.

  18. Formation, Accumulation, and Hydrolysis of Endogenous and Exogenous Formaldehyde-Induced DNA Damage.

    Science.gov (United States)

    Yu, Rui; Lai, Yongquan; Hartwell, Hadley J; Moeller, Benjamin C; Doyle-Eisele, Melanie; Kracko, Dean; Bodnar, Wanda M; Starr, Thomas B; Swenberg, James A

    2015-07-01

    Formaldehyde is not only a widely used chemical with well-known carcinogenicity but is also a normal metabolite of living cells. It thus poses unique challenges for understanding risks associated with exposure. N(2-)hydroxymethyl-dG (N(2)-HOMe-dG) is the main formaldehyde-induced DNA mono-adduct, which together with DNA-protein crosslinks (DPCs) and toxicity-induced cell proliferation, play important roles in a mutagenic mode of action for cancer. In this study, N(2)-HOMe-dG was shown to be an excellent biomarker for direct adduction of formaldehyde to DNA and the hydrolysis of DPCs. The use of inhaled [(13)CD2]-formaldehyde exposures of rats and primates coupled with ultrasensitive nano ultra performance liquid chromatography-tandem mass spectrometry permitted accurate determinations of endogenous and exogenous formaldehyde DNA damage. The results show that inhaled formaldehyde only reached rat and monkey noses, but not tissues distant to the site of initial contact. The amounts of exogenous adducts were remarkably lower than those of endogenous adducts in exposed nasal epithelium. Moreover, exogenous adducts accumulated in rat nasal epithelium over the 28-days exposure to reach steady-state concentrations, followed by elimination with a half-life (t1/2) of 7.1 days. Additionally, we examined artifact formation during DNA preparation to ensure the accuracy of nonlabeled N(2)-HOMe-dG measurements. These novel findings provide critical new data for understanding major issues identified by the National Research Council Review of the 2010 Environmental Protection Agency's Draft Integrated Risk Information System Formaldehyde Risk Assessment. They support a data-driven need for reflection on whether risks have been overestimated for inhaled formaldehyde, whereas underappreciating endogenous formaldehyde as the primary source of exposure that results in bone marrow toxicity and leukemia in susceptible humans and rodents deficient in DNA repair. © The Author 2015

  19. Effect of multiple adduct fullerenes on microstructure and phase behavior of P3HT:fullerene blend films for organic solar cells.

    Science.gov (United States)

    Guilbert, Anne A Y; Reynolds, Luke X; Bruno, Annalisa; MacLachlan, Andrew; King, Simon P; Faist, Mark A; Pires, Ellis; Macdonald, J Emyr; Stingelin, Natalie; Haque, Saif A; Nelson, Jenny

    2012-05-22

    The bis and tris adducts of [6,6]phenyl-C(61)-butyric acid methyl ester (PCBM) offer lower reduction potentials than PCBM and are therefore expected to offer larger open-circuit voltages and more efficient energy conversion when blended with conjugated polymers in photovoltaic devices in place of PCBM. However, poor photovoltaic device performances are commonly observed when PCBM is replaced with higher-adduct fullerenes. In this work, we use transmission electron microscopy (TEM), steady-state and ultrafast time-resolved photoluminescence spectroscopy (PL), and differential scanning calorimetry (DSC) to probe the microstructural properties of blend films of poly(3-hexylthiophene-2,5-diyl) (P3HT) with the bis and tris adducts of PCBM. TEM and PL indicate that, in as-spun blend films, fullerenes become less soluble in P3HT as the number of adducts increases. PL indicates that upon annealing crystallization leads to phase separation in P3HT:PCBM samples only. DSC studies indicate that the interactions between P3HT and the fullerene become weaker with higher-adduct fullerenes and that all systems exhibit eutectic phase behavior with a eutectic composition being shifted to higher molar fullerene content for higher-adduct fullerenes. We propose two different mechanisms of microstructure development for PCBM and higher-adduct fullerenes. P3HT:PCBM blends, phase segregation is the result of crystallization of either one or both components and is facilitated by thermal treatments. In contrast, for blends containing higher adducts, the phase separation is due to a partial demixing of the amorphous phases. We rationalize the lower photocurrent generation by the higher-adduct fullerene blends in terms of film microstructure.

  20. LC-DAD-ESI/MS(n) determination of direct condensation flavanol-anthocyanin adducts in pressure extracted pomegranate (Punica granatum L.) juice.

    Science.gov (United States)

    Sentandreu, Enrique; Navarro, Jose L; Sendra, Jose M

    2010-10-13

    Pomegranate (Punica granatum L.) juice, obtained by pressure extraction of the whole fruit, has been analyzed for its flavanol-anthocyanin adduct content using reversed-phase liquid chromatography with diode array detection, coupled to mass spectrometry (ion trap) with electrospray ionization (HPLC-DAD-ESI/MS(n)), operating in positive ion mode. A total of 35 dimers have been detected, consisting of mono- and disubstituted hexoside derivatives of the adducts between the flavan-3-ols (epi)gallocatechin, (epi)catechin and (epi)afzelechin and the anthocyanidins delphinidin, cyanidin and pelargonidin. In addition, evidence is given for the presence of additional anthocyanin-flavanol adducts in this juice.

  1. One-electron oxidation of a pyrenyl photosensitizer covalently attached to DNA and competition between its further oxidation and DNA hole injection.

    Science.gov (United States)

    Yun, Byeong Hwa; Dedon, Peter C; Geacintov, Nicholas E; Shafirovich, Vladimir

    2010-01-01

    The photosensitized hole injection and guanine base damage phenomena have been investigated in the DNA sequence, 5'-d(CATG(1)(Py)CG(2)TCCTAC) with a site-specifically positioned pyrene-like (Py) benzo[a]pyrene 7,8-diol 9,10-epoxide-derived N(2)-guanine adduct (G(1)(Py)). Generation of the Py radical cation and subsequent hole injection into the DNA strand by a 355 nm nanosecond laser pulses (approximately 4 mJ cm(-2)) results in the transformation of G(1)(Py) to the imidazolone derivative Iz(1)(Py) and a novel G(1)(Py*) photoproduct that has a mass larger by 16 Da (M+16) than the mass (M) of G(1)(Py). In addition, hole transfer and the irreversible oxidation of G(2), followed by the formation of Iz(2) was observed (Yun et al. [2007], J. Am. Chem. Soc., 129, 9321). Oxygen-18 and deuterium isotope labeling methods, in combination with an extensive analysis of the MS/MS fragmentation patterns of the individual dG(Py*) nucleoside adduct and other data show that dG(Py*) has an unusual structure with a ruptured cyclohexenyl ring with a carbonyl group at the rupture site and intact guanine and pyrenyl residues. The formation of this product competes with hole injection and thus diminishes the efficiency of oxidation of guanines within the oligonucleotide strand by at least 15% in comparison with that in the dG(Py) nucleoside adduct.

  2. The stability of DNA intrastrand cross-links of antitumor transplatin derivative containing non-bulky methylamine ligands.

    Science.gov (United States)

    Frybortova, Michaela; Novakova, Olga; Brabec, Viktor

    2014-10-01

    Oligonucleotides modified by clinically ineffective trans-diamminedichloridoplatinum(II) (transplatin) have been shown to be effective modulators of gene expression. This is so because in some nucleotide sequences the 1,3-GNG intrastrand adducts formed by transplatin in double-helical DNA readily rearrange into interstrand cross-links so that they can cross-link the oligonucleotides to their targets. On the other hand, in a number of other sequences these intrastrand adducts are relatively stable, which represents the major difficulty in the clinical use of the antisense transplatin-modified oligonucleotides. Therefore, we examined in this study, the stability of 1,3-GNG intrastrand adducts in double-helical DNA formed by a new antitumor derivative of transplatin, trans-[Pt(CH3NH2)2Cl2], in the sequence contexts in which transplatin formed relatively stable intrastrand cross-links which did not readily rearranged into interstrand cross-links. We have found that 1,3-GNG intrastrand adducts in double-helical DNA formed by trans-[Pt(CH3NH2)2Cl2] even in such sequences readily rearrange into interstrand cross-links. This work also suggests that an enhanced frequency of intrastrand cross-links yielded by trans-[Pt(CH3NH2)2Cl2] is a consequence of the fact that these DNA lesions considerably distort double-helical DNA in far more sequence contexts than parent transplatin. Our results suggest that trans-[Pt(CH3NH2)2Cl2]-modified oligonucleotides represent promising candidates for new agents in antisense or antigene approach.

  3. 8-hydroxydeoxyguanosine as a biomarker of oxidative DNA damage induced by environmental tobacco side-stream smoke and its mechanism.

    Science.gov (United States)

    Xi, Zhu-Ge; Chao, Fu-Huan; Yang, Dan-Feng; Zhang, Hua-Shan; Zhang, Wei

    2005-02-01

    To study the genotoxicity effect of environmental tobacco side-stream smokes (ETSS) on oxidative DNA damage and its molecular mechanism. DNA adduct 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage. The level of 8-OHdG in DNA exposed to ETSS was detected by high performance liquid chromatography with electrochemical detection. Organic and inorganic components in ETSS were analyzed by gas chromatography-mass spectrum and atomic absorption spectrum respectively. Particle matters (PMs) and volatile organic compounds (VOCs) in ETSS could directly induce oxidative DNA damage and formation of 8-OHdG. There were 123 and 84 kinds of organic components in PMs and VOCs respectively, and 7 kinds of inorganic components in ETSS. Some components, especially quinones and polyphenols in ETSS, could produce free radicals in vitro by auto-oxidation without any biological activity systems, and with the catalytic reaction of metals, the DNA adduct 8-OHdG was produced. ETSS have biological oxidative effect on DNA in vitro and in vivo, and expressed direct genotoxicity. 8-OHdG is a valuable biomarker of oxidative DNA damage.

  4. Ddc1 checkpoint protein and DNA polymerase ɛ interact with nick-containing DNA repair intermediate in cell free extracts of Saccharomyces cerevisiae.

    Science.gov (United States)

    Sukhanova, Maria V; D'Herin, Claudine; van der Kemp, Patricia Auffret; Koval, Vladimir V; Boiteux, Serge; Lavrik, Olga I

    2011-08-15

    To characterize proteins that interact with base excision/single-strand interruption repair DNA intermediates in cell free extracts of Saccharomyces cerevisiae, we used a combination of photoaffinity labeling with the protein identification by MALDI-TOF-MS peptide mapping. Photoreactive analogue of dCTP, namely exo-N-[4-(4-azido-2,3,5,6,-tetrafluorobenzylidenehydrazinocarbonyl)-butylcarbamoyl]-2'-deoxycytidine-5'-triphosphate, and [(32)P]-labeled DNA duplex containing one nucleotide gap were used to generate nick-containing DNA with a photoreactive dCMP residue at the 3'-margin of the nick. This photoreactive DNA derivative was incubated with the yeast cell extract and after UV irradiation a number of proteins were labeled. Two of the crosslinked proteins were identified as the catalytic subunit of DNA polymerase ɛ and Ddc1 checkpoint protein. Labeling of DNA polymerase ɛ catalytic subunit with the nick-containing DNA repair intermediate indicates that the DNA polymerase is involved in the DNA repair synthesis in yeast, at least at DNA single-strand interruptions. Crosslinking of Ddc1 to DNA nicks took place independently of the other components of checkpoint clamp, Mec3 and Rad17, suggesting that the protein alone is able to recognize DNA single-strand breaks. Indeed, purified GST-tagged Ddc1 protein was efficiently crosslinked to nick-containing DNA. The interaction of Ddc1 with DNA nicks may provide a link between the DNA damage checkpoint and DNA base excision/single-strand breaks repair pathways in yeast. In addition, we found that absence of Ddc1 protein greatly influences the overall pattern of other proteins crosslinked to DNA nick. We suggested that this last effect of Ddc1 is at least partially due to its capacity to prevent proteolytic degradation of the DNA-protein adducts. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Diversely substituted sugar-linked alpha,beta-unsaturated gamma-lactones from sugar-derived Baylis-Hillman adducts via a RCM.

    Science.gov (United States)

    Krishna, Palakodety Radha; Narsingam, M

    2007-01-01

    A versatile protocol for the production of sugar-linked alpha,beta-unsaturated gamma-lactones with stereochemical and functional group diversity is described starting from sugar-derived Baylis-Hillman adducts via ring-closing metathesis.

  6. DNA glue

    DEFF Research Database (Denmark)

    Filichev, Vyacheslav V; Astakhova, Irina V.; Malakhov, Andrei D.

    2008-01-01

    Significant alterations in thermal stability of parallel DNA triplexes and antiparallel duplexes were observed upon changing the attachment of ethynylpyrenes from para to ortho in the structure of phenylmethylglycerol inserted as a bulge into DNA (TINA). Insertions of two ortho-TINAs as a pseudo...

  7. DNA Vaccines

    Indian Academy of Sciences (India)

    research interests include: eukaryotic gene expres- sion and infectious diseases. Keywords. DNA vaccine, immune response, antibodies, infectious diseases. GENERAL I ... T -cells: Lymphocytes that differentiate primarily in the thymus and are central to the control and ... enhance DNA delivery into skeletal muscle.

  8. Ferrocenyl Quinone Methide-Thiol Adducts as New Antiproliferative Agents: Synthesis, Metabolic Formation from Ferrociphenols, and Oxidative Transformation

    OpenAIRE

    Wang, Yong; Richard, Marie-Aude; Top, Siden; Dansette, Patrick M; Pigeon, Pascal; Vessières, Anne; Mansuy, Daniel; Jaouen, Gérard

    2016-01-01

    International audience; Ferrociphenols (FCs) and their oxidized, electrophilic quinone methide metabolites (FC-QMs) are organometallic compounds related to tamoxifen that exhibit strong antiproliferative properties. To evaluate the reactivity of FC-QMs towards cellular nucleophiles, we studied their reaction with selected thiols. A series of new compounds resulting from the addition of these nucleophiles, the FC-SR adducts, were thus synthesized and completely characterized. Such conjugates a...

  9. Synthesis and NMR Spectral Studies of the 7-C60-Adduct of N,N-(Tetrachlorophthaloyl Dehydroabietylamine

    Directory of Open Access Journals (Sweden)

    Zhi Zhou

    2012-04-01

    Full Text Available The 7-C60-adduct of N,N-(tetrachlorophthaloyldehydroabietylamine was synthesized for the first time and characterized by IR, UV-vis, mass and NMR spectral studies. The 1H-NMR and 13C-NMR resonance signals of the new compound are unambiguously assigned by using homo- and heteronuclear 2D NMR spectroscopic techniques such as COSY, ROESY, HSQC and HMBC. The C1 symmetric structure with 6,6-junction of compound was determined.

  10. A synthesis of oxo-thioxo[3.3.3]propellanes from dithiocarbamates and ninhydrin-malononitrile adduct.

    Science.gov (United States)

    Yavari, Issa; Khajeh-Khezri, Aliyeh

    2017-11-01

    An efficient method for the synthesis of oxo-thioxo[3.3.3]propellanes via reaction of dithiocarbamates, generated from primary amines and carbon disulfide, with the Knoevenagel adduct resulting from ninhydrin and malononitrile in [Formula: see text] at room temperature is described. These transformations are highlighted by their chemo- and regioselectivity, lack of activator or metal promoters, inert atmosphere, and formation of four new bonds in one operation.

  11. Limits of the manipulative-fixed method for measurement of shoulder joint horizontal adduction muscle strength using a handheld dynamometer

    OpenAIRE

    Hirano, Masahiro; Katoh, Munenori

    2015-01-01

    [Purpose] The aim of this study was to verify the limit of isometric muscle strength of shoulder joint horizontal adduction using handheld dynamometer (HHD) manipulated by hand (referred to as the manipulative-fixed method). [Subjects and Methods] The subjects were 33 healthy college students. The examiner was a healthy college student. Shoulder joint horizontal adductor muscle strength was measured using HHD with the subject in the supine position. The belt-fixed and manipulative-fixed metho...

  12. Feasibility of Biomonitoring of Exposure to Permethrin Through Analysis of Long-Lived (Metabolite) Adducts to Proteins

    Science.gov (United States)

    2009-04-01

    particular amino acid residues are modified by penicillin (Yvon et al., 1989), and that the resulting adduct is involved in allergic reactions . On the...biomarkers for chronic exposure to permethrin, since the O-acyl glucuronides represent a unique class of electrophilic metabolites, capable of reaction ...with nucleophilic sites in proteins. Numerous examples of these reactions have been documented in which the O-acyl glucuronides originated from

  13. Dietary and lifestyle determinants of acrylamide and glycidamide hemoglobin adducts in non-smoking postmenopausal women from the EPIC cohort.

    Science.gov (United States)

    Obón-Santacana, Mireia; Lujan-Barroso, Leila; Freisling, Heinz; Cadeau, Claire; Fagherazzi, Guy; Boutron-Ruault, Marie-Christine; Kaaks, Rudolf; Fortner, Renée T; Boeing, Heiner; Ramón Quirós, J; Molina-Montes, Esther; Chamosa, Saioa; Castaño, José María Huerta; Ardanaz, Eva; Khaw, Kay-Tee; Wareham, Nick; Key, Tim; Trichopoulou, Antonia; Lagiou, Pagona; Naska, Androniki; Palli, Domenico; Grioni, Sara; Tumino, Rosario; Vineis, Paolo; De Magistris, Maria Santucci; Bueno-de-Mesquita, H B; Peeters, Petra H; Wennberg, Maria; Bergdahl, Ingvar A; Vesper, Hubert; Riboli, Elio; Duell, Eric J

    2017-04-01

    Acrylamide was classified as 'probably carcinogenic' to humans in 1994 by the International Agency for Research on Cancer. In 2002, public health concern increased when acrylamide was identified in starchy, plant-based foods, processed at high temperatures. The purpose of this study was to identify which food groups and lifestyle variables were determinants of hemoglobin adduct concentrations of acrylamide (HbAA) and glycidamide (HbGA) in 801 non-smoking postmenopausal women from eight countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Biomarkers of internal exposure were measured in red blood cells (collected at baseline) by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) . In this cross-sectional analysis, four dependent variables were evaluated: HbAA, HbGA, sum of total adducts (HbAA + HbGA), and their ratio (HbGA/HbAA). Simple and multiple regression analyses were used to identify determinants of the four outcome variables. All dependent variables (except HbGA/HbAA) and all independent variables were log-transformed (log2) to improve normality. Median (25th-75th percentile) HbAA and HbGA adduct levels were 41.3 (32.8-53.1) pmol/g Hb and 34.2 (25.4-46.9) pmol/g Hb, respectively. The main food group determinants of HbAA, HbGA, and HbAA + HbGA were biscuits, crackers, and dry cakes. Alcohol intake and body mass index were identified as the principal determinants of HbGA/HbAA. The total percent variation in HbAA, HbGA, HbAA + HbGA, and HbGA/HbAA explained in this study was 30, 26, 29, and 13 %, respectively. Dietary and lifestyle factors explain a moderate proportion of acrylamide adduct variation in non-smoking postmenopausal women from the EPIC cohort.

  14. Effect of increased intake of dietary animal fat and fat energy on oxidative damage, mutation frequency, DNA adduct level and DNA repair in rat colon and liver

    DEFF Research Database (Denmark)

    Vogel, Ulla; Daneshvar, Bahram; Autrup, Herman

    2003-01-01

    The effect of high dietary intake of animal fat and an increased fat energy intake on colon and liver genotoxicity and on markers of oxidative damage and antioxidative defence in colon, liver and plasma was investigated in Big Blue rats. The rats were fed ad libitum with semi-synthetic feed suppl...

  15. Observation of CO2 and solvent adduct ions during negative mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometric analysis of monohydric alcohols.

    Science.gov (United States)

    Zhou, Xibin; Zhang, Yahe; Zhao, Suoqi; Hsu, Chang Samuel; Shi, Quan

    2013-12-15

    Monohydric alcohols are common in natural products, bio-oils, and medicine. We have found that monohydric alcohols can form O3 (ions containing three oxygen atoms) and O4 adduct ions in negative electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), which would significantly affect the composition analysis of alcohols, especially in a complex mixture. It is necessary to study the reaction pathways and the method to eliminate or reduce the 'artifact' adducts. Octadecanol, cholesterol, squalanol and two complex monohydric alcohol mixtures were selected as model compounds. These samples were subjected to negative ion ESI FT-ICR MS analysis. The composition and formation mechanism of adducts were studied by the ultrahigh-resolution accurate mass measurement for elemental composition, along with the MS(2) isolation and collision-induced dissociation (CID) experiments for structural determination. The reaction pathway of O3 adduct formation is the coupling of a monohydric alcohol ion with a CO2 to form a stable O3 ionic species by likely a covalent bond (source of CO2 is not clear). The O4 species are formed by O3 ionic species adducted with an alcohol molecule of the solvent, such as methanol or ethanol, by likely a hydrogen bond. These adduct ions could be eliminated or reduced by increasing collision energy. However, excessive collision energy would fragment monohydric alcohol ions. The formation mechanisms of O3 and O4 adducts from monohydric alcohols in negative ion ESI FT-ICR MS were proposed. The solvent adduction effects can be eliminated or reduced by optimizing the collision energy of CID in FT-ICR MS. Copyright © 2013 John Wiley & Sons, Ltd.

  16. S-adenosyl-L-methionine protection of acetaminophen mediated oxidative stress and identification of hepatic 4-hydroxynonenal protein adducts by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, James Mike [Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Huntington, WV (United States); Kuhlman, Christopher [Southwest Environmental Health Sciences Center, Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona Health Sciences Center, Tucson, AZ (United States); Terneus, Marcus V. [Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Huntington, WV (United States); Labenski, Matthew T. [Southwest Environmental Health Sciences Center, Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona Health Sciences Center, Tucson, AZ (United States); Lamyaithong, Andre Benja; Ball, John G. [Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Huntington, WV (United States); Lau, Serrine S. [Southwest Environmental Health Sciences Center, Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona Health Sciences Center, Tucson, AZ (United States); Valentovic, Monica A., E-mail: Valentov@marshall.edu [Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Huntington, WV (United States)

    2014-12-01

    Acetaminophen (APAP) hepatotoxicity is protected by S-adenosyl-L-methionine (SAMe) treatment 1 hour (h) after APAP in C57/Bl6 mice. This study examined protein carbonylation as well as mitochondrial and cytosolic protein adduction by 4-hydroxynonenal (4-HNE) using mass spectrometry (MS) analysis. Additional studies investigated the leakage of mitochondrial proteins and 4-HNE adduction of these proteins. Male C57/Bl6 mice (n = 5/group) were divided into the following groups and treated as indicated: Veh (15 ml/kg water, ip), SAMe (1.25 mmol/kg, ip), APAP (250 mg/kg), and SAMe given 1 h after APAP (S + A). APAP toxicity was confirmed by an increase (p < 0.05) in plasma ALT (U/l) and liver weight/10 g body weight relative to the Veh, SAMe and S + A groups 4 h following APAP treatment. SAMe administered 1 h post-APAP partially corrected APAP hepatotoxicity as ALT and liver weight/10 g body weights were lower in the S + A group compared the APAP group. APAP induced leakage of the mitochondrial protein, carbamoyl phosphate synthase-1 (CPS-1) into the cytosol and which was reduced in the S + A group. SAMe further reduced the extent of APAP mediated 4-HNE adduction of CPS-1. MS analysis of hepatic and mitochondrial subcellular fractions identified proteins from APAP treated mice. Site specific 4-HNE adducts were identified on mitochondrial proteins sarcosine dehydrogenase and carbamoyl phosphate synthase-1 (CPS-1). In summary, APAP is associated with 4-HNE adduction of proteins as identified by MS analysis and that CPS-1 leakage was greater in APAP treated mice. SAMe reduced the extent of 4-HNE adduction of proteins as well as leakage of CPS-1. - Highlights: • Acetaminophen (APAP) toxicity protected by S-adenosylmethionine (SAMe) • 4-Hydroxynonenal adducted to sarcosine dehydrogenase • 4-Hydroxynonenal adducted to carbamoyl phosphate synthetase-1 • SAMe reduced APAP mediated CPS-1 mitochondrial leakage.

  17. Effects of alkyl chain length and substituent pattern of fullerene bis-adducts on film structures and photovoltaic properties of bulk heterojunction solar cells.

    Science.gov (United States)

    Tao, Ran; Umeyama, Tomokazu; Kurotobi, Kei; Imahori, Hiroshi

    2014-10-08

    A series of alkoxycarbonyl-substituted dihydronaphthyl-based [60]fullerene bis-adduct derivatives (denoted as C2BA, C4BA, and C6BA with the alkyl chain of ethyl, n-butyl, and n-hexyl, respectively) have been synthesized to investigate the effects of alkyl chain length and substituent pattern of fullerene bis-adducts on the film structures and photovoltaic properties of bulk heterojunction polymer solar cells. The shorter alkyl chain length caused lower solubility of the fullerene bis-adducts (C6BA > C4BA > C2BA), thereby resulting in the increased separation difficulty of respective bis-adduct isomers. The device performance based on poly(3-hexylthiophene) (P3HT) and the fullerene bis-adduct regioisomer mixtures was enhanced by shortening the alkyl chain length. When using the regioisomerically separated fullerene bis-adducts, the devices based on trans-2 and a mixture of trans-4 and e of C4BA exhibited the highest power conversion efficiencies of ca. 2.4%, which are considerably higher than those of the C6BA counterparts (ca. 1.4%) and the C4BA regioisomer mixture (1.10%). The film morphologies as well as electron mobilities of the P3HT:bis-adduct blend films were found to affect the photovoltaic properties considerably. These results reveal that the alkyl chain length and substituent pattern of fullerene bis-adducts significantly influence the photovoltaic properties as well as the film structures of bulk heterojunction solar cells.

  18. Synthesis of oxa-bridged derivatives from Diels–Alder bis-adducts of butadiene and 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene

    Directory of Open Access Journals (Sweden)

    Faiz Ahmed Khan

    2010-06-01

    Full Text Available Bis-adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene and 1,3-butadiene, generated in situ from 3-sulfolene, have been synthesized in excellent yield. Ruthenium catalyzed oxidation of the bis-adducts followed by a one-pot transformation of the resulting α-diketone furnished oxa-bridged compounds. Unambiguous stereochemical assignments of both diastereomeric series are reported.

  19. An experiment on apoptosis induced by polyamine adducts produced in the presence of serum amine oxidase.

    Science.gov (United States)

    Fajardo; Urdiales; Sánchez-Jiménez; Medina

    2000-03-01

    A two-session experiment is proposed to train students with an easy, economic and educative procedure to detect the typical DNA ladder produced in many apoptotic events. The procedure is accurate enough to provide an easy way to compare degrees of damage in DNA caused by different treatments.

  20. Electron Capture Dissociation of Divalent Metal-adducted Sulfated N-Glycans Released from Bovine Thyroid Stimulating Hormone

    Science.gov (United States)

    Zhou, Wen; Håkansson, Kristina

    2013-11-01

    Sulfated