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Chemical Research in Toxicology

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https://www.readbyqxmd.com/read/29148816/assessment-of-anti-piperacillin-igg-binding-to-structurally-related-drug-protein-adducts
#1
Mohammed Amali, Rosalind Jenkins, Xioali Meng, Lee Faulkner, Paul Whitaker, Daniel Peckham, B Kevin Park, Dean John Naisbitt
The risk of developing hypersensitivity to alternative antibiotics is a concern for penicillin hypersensitive patients and healthcare pro-viders. Herein we use piperacillin hypersensitivity as a model to explore the reactivity of drug-specific IgG against alternative β-lactam protein adducts. Mass spectrometry was used to show the drugs (amoxicillin, flucloxacillin, benzyl penicillin, aztreonam and pipera-cillin) bind to similar lysine residues on the protein carrier bovine serum albumin. However, the hapten-specific IgG antibodies found in piperacillin hypersensitive patient plasma did not bind to other β-lactam protein conjugates...
November 17, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29092396/refinement-of-a-methodology-for-untargeted-detection-of-serum-albumin-adducts-in-human-populations
#2
George W Preston, Michelle Plusquin, Osman Sozeri, Karin van Veldhoven, Lilian Bastian, Tim S Nawrot, Marc Chadeau-Hyam, David H Phillips
Covalently modified blood proteins (e.g., serum albumin adducts) are increasingly being viewed as potential biomarkers via which the environmental causes of human diseases may be understood. The notion that some (perhaps many) modifications have yet to be discovered has led to the development of untargeted adductomics methods, which attempt to capture entire populations of adducts. One such method is fixed-step selected reaction monitoring (FS-SRM), which analyses distributions of serum albumin adducts via shifts in the mass of a tryptic peptide [Li et al...
November 17, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29035044/nicotine-alters-the-gut-microbiome-and-metabolites-of-gut-brain-interactions-in-a-sex-specific-manner
#3
Liang Chi, Ridwan Mahbub, Bei Gao, Xiaoming Bian, Pengcheng Tu, Hongyu Ru, Kun Lu
As the primary active substance in tobacco, nicotine affects the activity of the central nervous system, and its effects are sex-dependent. There are complex interactions between the gut and brain, and the gut microbiome can influence neuronal activity and host behavior, with diverse chemical signaling being involved. However, it is unclear whether nicotine can affect the normal gut microbiome and associated chemical signaling of the gut-brain axis. Sex is an important factor that shapes the gut microbiome, but the role of sex in the interaction among nicotine, gut bacteria, and related metabolites remains unknown...
November 16, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29137457/monoclonal-antibody-that-recognizes-diethoxyphospho-tyrosine-modified-proteins-and-peptides-independent-of-surrounding-amino-acids
#4
Seda Onder, Alicia J Dafferner, Lawrence M Schopfer, Gaoping Xiao, Udaya Yerramalla, Ozden Tacal, Thomas A Blake, Rudolph C Johnson, Oksana Lockridge
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are irreversibly inhibited by organophosphorus pesticides through formation of a covalent bond with the active site serine. Proteins that have no active site serine, for example albumin, are covalently modified on tyrosine and lysine. Chronic illness from pesticide exposure is not explained by inhibition of AChE and BChE. Our goal was to produce a monoclonal antibody that recognizes proteins diethoxyphosphorylated on tyrosine. Diethoxyphosphate-tyrosine adducts for 13 peptides were synthesized...
November 14, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29131934/methyl-dna-phosphate-adduct-formation-in-rats-treated-chronically-with-4-methylnitrosamino-1-3-pyridyl-1-butanone-and-enantiomers-of-its-metabolite-4-methylnitrosamino-1-3-pyridyl-1-butanol
#5
Bin Ma, Adam T Zarth, Erik S Carlson, Peter W Villalta, Pramod Upadhyaya, Irina Stepanov, Stephen S Hecht
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 tobacco users. NNK is stereoselectively and reversibly metabolized to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which is also a lung carcinogen. Both NNK and NNAL undergo metabolic activation by α-hydroxylation on their methyl groups to form pyridyloxobutyl and pyridylhydroxybutyl DNA base and phosphate adducts, respectively...
November 13, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29129070/molecular-signatures-associated-with-treatment-of-triple-negative-mda-mb231-breast-cancer-cells-with-histone-deacetylase-inhibitors-jaha-and-saha
#6
Mariangela Librizzi, Fabio Caradonna, Ilenia Cruciata, Janusz Dębski, Supojjanee Sansook, Michał Dadlez, John Spencer, Claudio Luparello
Jay Amin hydroxamic acid (JAHA; N8-ferrocenylN(1)-hydroxy-octanediamide) is a ferrocene-containing analogue of the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA). JAHA's cytotoxic activity on MDA-MB231 triple negative breast cancer (TNBC) cells at 72 h has been previously demonstrated with an IC50 of 8.45 μM. JAHA's lethal effect was found linked to perturbations of cell cycle, mitochondrial activity, signal transduction, and autophagy mechanisms. To glean novel insights on how MDA-MB231 breast cancer cells respond to the cytotoxic effect induced by JAHA, and to compare the biological effect with the related compound SAHA, we have employed a combination of differential display-PCR, proteome analysis, and COMET assay techniques and shown some differences in the molecular signature profiles induced by exposure to either HDACis...
November 12, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29120619/a-rapid-throughput-method-to-extract-dna-from-formalin-fixed-paraffin-embedded-tissues-for-biomonitoring-carcinogenic-dna-adducts-in-humans
#7
Byeong Hwa Yun, Shun Xiao, Lihua Yao, Sesha Krishnamachari, Thomas A Rosenquist, Kathleen G Dickman, Arthur P Grollman, Paari Murugan, Christopher J Weight, Robert J Turesky
Formalin-fixed paraffin-embedded (FFPE) tissues are rarely used for screening DNA adducts of carcinogens because the harsh conditions required to reverse the formaldehyde-mediated DNA cross-links can destroy DNA adducts. We recently adapted a commercial silica-based column kit used in genomics to manually isolate DNA under mild conditions from FFPE tissues of rodents and humans and successfully measured DNA adducts of several carcinogens including aristolochic acid I (AA-I), 4-aminobiphenyl (4-ABP), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (Yun et al...
November 9, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29116760/the-relative-propensities-of-cytochrome-c-oxidase-and-cobalt-corrins-for-reaction-with-cyanide-and-oxygen-implications-for-amelioration-of-cyanide-toxicity
#8
Quan Yuan, Linda Lorraine Pearce, Jim Peterson
In aqueous media at neutral pH, the binding of two cyanide molecules per cobinamide can be described by two formation constants, Kf1 = 1.1 (±0.6) × 105 M-1 and Kf2 = 8.5 (±0.1) × 104 M-1, or an overall cyanide binding constant of ~1 × 1010 M-2. In comparison, the cyanide binding constants for cobalamin and a fully oxidized form of cytochrome c oxidase, each binding a single cyanide anion, were found to be 7.9 (±0.5) × 104 M-1 and 1.6 (±0.2) × 107 M-1, respectively. An examination of the cyanide-binding properties of cobinamide at neutral pH by stopped-flow spectrophotometry revealed two kinetic phases, rapid and slow, with apparent second-order rate constants of 3...
November 8, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29116755/capture-of-cadmium-by-reactive-polysulfides-attenuates-cadmium-induced-adaptive-responses-and-hepatotoxicity
#9
Masahiro Akiyama, Yasuhiro Shinkai, Takamitsu Unoki, Ilseob Shim, Isao Ishii, Yoshito Kumagai
Cadmium (Cd) is an environmental electrophile modifying protein nucleophiles, thereby modulating cellular signaling and toxicity. While reactive persulfides/polysulfides exhibit relatively high nucleophilic properties, their roles in the altered gene expression and toxicity caused by Cd remain unclear. Exposing primary mouse hepatocytes to Cd caused heat shock protein 70 (HSP70) and metallothionein (MT)-I/II to be upregulated and cytotoxicity to occur. These effects were blocked in the presence of polysulfide sodium tetrasulfide (Na2S4)...
November 8, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29111684/correction-to-a-chemoproteomic-platform-to-assess-bioactivation-potential-of-drugs
#10
Rui Sun, Fuguo Shi, Keke Liu, Ling Fu, Caiping Tian, Yong Yang, Keri A Tallman, Ned A Porter, Jing Yang
No abstract text is available yet for this article.
November 7, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29099997/early-metabolome-profiling-and-prognostic-value-in-paraquat-poisoned-patients-based-on-ultra-performance-liquid-chromatography-coupled-to-quadrupole-time-of-flight-mass-spectrometry
#11
Lufeng Hu, Guangliang Hong, Yahui Tang, Xianqin Wang, Congcong Wen, Feiyan Lin, Zhongqiu Lu
Paraquat (PQ) has caused countless deaths throughout the world. There remains no effective treatment for PQ poisoning. Here we study the blood metabolome of PQ-poisoned patient using ultra performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Patients were divided into groups according blood PQ concentration. Healthy subjects served as controls. Metabolic features were statistically analyzed using multivariate pattern-recognition techniques to identify the most important metabolites...
November 3, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29064675/age-dependent-effects-of-acute-alcohol-administration-in-the-hippocampal-phosphoproteome
#12
Ana Contreras, Lidia Morales, Ali Tebourbi, Miguel Miguéns, Nuria Del Olmo, Carmen Pérez-García
Alcohol consumption during adolescence is deleterious to the developing brain and leads to persistent deficits in adulthood. Several results provide strong evidence for ethanol-associated alterations in glutamatergic signaling and impaired synaptic plasticity in the hippocampus. Protein phosphorylation is a well-known and well-documented mechanism in memory processes, but information on phosphoprotein alterations in hippocampus after ethanol exposure is limited. This study focuses on age-related changes in the hippocampal phosphoproteome after acute alcohol administration...
November 3, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29088535/sulfide-toxicity-and-its-modulation-by-nitric-oxide-in-bovine-pulmonary-artery-endothelial-cells
#13
Kristin L Frawley, Andrea A Cronican, Linda Lorraine Pearce, Jim Peterson
Bovine pulmonary artery endothelial cells (BPAEC) respond in a dose-dependent manner to millimolar (0-10) levels of sodium sulfide (NaHS). No measurable increase in caspase-3 activity and no change in the extent of autophagy (or mitophagy) was observed in BPAEC. However, lactate dehydrogenase levels increased in the BPAEC exposed NaHS indicating necrotic cell death. In the case of galactose-conditioned BPAEC, the toxicity of NaHS was increased by 30% compared to that observed in BPAEC maintained in the regular glucose-containing culture medium, indicating a link between mitochondrial oxidative phosphorylation and the mechanism of toxicant action...
October 31, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29035516/potential-metabolic-activation-of-representative-alkylated-polycyclic-aromatic-hydrocarbons-1-methylphenanthrene-and-9-ethylphenanthrene-associated-with-the-deepwater-horizon-oil-spill-in-human-hepatoma-hepg2-cells
#14
Meng Huang, Clementina Mesaros, Linda C Hackfeld, Richard P Hodge, Ian A Blair, Trevor M Penning
Exposure to petrogenic polycyclic aromatic hydrocarbons (PPAHs) is the major human health hazard associated with the Deepwater Horizon oil spill. Alkylated phenanthrenes are the most abundant PPAHs present in the crude oil and could contaminate the food chain. We describe the metabolism of a C1-phenanthrene regioisomer 1-methylphenanthrene (1-MP) and a C2-phenanthrene regioisomer 9-ethylphenanthrene (9-EP) in human HepG2 cells. The structures of the metabolites were identified by HPLC-UV-fluorescence detection and LC-MS/MS...
October 27, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29068672/effects-of-black-raspberry-extract-and-berry-compounds-on-repair-of-dna-damage-and-mutagenesis-induced-by-chemical-and-physical-agents-in-human-oral-leukoplakia-and-rat-oral-fibroblasts
#15
Joseph Guttenplan, Kun-Ming Chen, Yuan-Wan Sun, Braulio Lajara, Nora Ae Shalaby, Wieslawa Kosinska, Gabrielle Benitez, Krishne Gowda, Shantu Amin, Gary David Stoner, Karam El-Bayoumy
Black raspberries (BRB) have been shown to inhibit carcinogenesis in a number of systems, with most studies focusing on progression. Previously we reported that an anthocyanin-enriched black raspberry extract (BE) enhanced repair of dibenzo[a,l]pyrene dihydrodiol (DBP-diol) induced DNA adducts and inhibited DBP-diol and DBP-diolepoxide (DBPDE)-induced mutagenesis in a lacI rat oral fibroblast cell line, suggesting a role for BRB in the inhibition of initiation of carcinogenesis. Here we extend this work to protection by BE, against DNA adduct formation induced by dibenzo[a,l]pyrene (DBP) in a human oral leukoplakia cell line (MSK) and to second carcinogen, UV light...
October 25, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29053918/active-site-interactions-impact-phosphoryl-transfer-during-replication-of-damaged-and-undamaged-dna-by-escherichia-coli-dna-polymerase-i
#16
A S Prakasha Gowda, Thomas E Spratt
Replicative DNA polymerases are able to discriminate between very similar substrates with high accuracy. One mechanism by which E. coli DNA polymerase I checks for Watson-Crick geometry is through a hydrogen bonding fork between Arg668 and the incoming dNTP and the minor groove of the primer terminus. The importance of the Arg-fork was examined by disrupting it with either a guanine to 3-deazaguanine substitution at the primer terminus or the use of a carbocyclic deoxyribose analog of dUTP. Using thio-substituted dNTPs and differential quench techniques, we determined that when the Arg-fork was disrupted, the rate-limiting step changed from a conformational change to phosphodiester bond formation...
October 25, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28985473/red-clover-aryl-hydrocarbon-receptor-ahr-and-estrogen-receptor-er-agonists-enhance-genotoxic-estrogen-metabolism
#17
Tareisha L Dunlap, Caitlin E Howell, Nita Mukand, Shao-Nong Chen, Guido F Pauli, Birgit M Dietz, Judy L Bolton
Many women consider botanical dietary supplements (BDSs) as safe alternatives to hormone therapy for menopausal symptoms. However, the effect of BDSs on breast cancer risk is largely unknown. In the estrogen chemical carcinogenesis pathway, P450 1B1 metabolizes estrogens to 4-hydroxylated catechols, which are oxidized to genotoxic quinones that initiate and promote breast cancer. In contrast, P450 1A1 catalyzed 2-hydroxylation represents a detoxification pathway. The current study evaluated the effects of red clover, a popular BDS used for women's health, and its isoflavones, biochanin A (BA), formononetin (FN), genistein (GN), and daidzein (DZ), on estrogen metabolism...
October 19, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29045131/dapsone-and-nitroso-dapsone-activation-of-na%C3%A3-ve-t-cells-from-healthy-donors
#18
Abdulaziz Alzahrani, Monday O Ogese, Xioali Meng, James Waddington, Arun Tailor, John Farrell, James L Maggs, Catherine J Betts, B Kevin Park, Dean John Naisbitt
Dapsone (DDS) causes hypersensitivity reactions in 0.5-3.6% of patients. Although clinical diagnosis is indicative of a hypersensitivity reaction, studies have not been performed to define whether dapsone or a metabolite activates specific T-cells. Thus, the aims of this study were to explore the immunogenicity DDS and nitroso DDS (DDS-NO) using PBMC from healthy donors and splenocytes from mice and generate human T-cell clones to characterize mechanisms of T-cell activation. DDS-NO was synthesized from DDS-hydroxylamine and shown to bind to the thiol group of glutathione and human and mouse albumin through sulfonamide and N-hydroxyl sulphonamide adducts...
October 18, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28968073/simultaneous-mass-spectrometric-analysis-of-methylated-and-ethylated-peptides-in-human-hemoglobin-correlation-with-cigarette-smoking
#19
Hauh-Jyun Candy Chen, Sun Wai Ip, Fu-Di Lin
Alkylating agents contained in cigarettes smoke might be related to cancer development. Post-translational protein methylation and ethylation may cause alteration of protein functions. Human hemoglobin (Hb) has been a target for molecular dosimetry because of its easy accessibility. The goal of this study is to investigate the relationship between the levels of methylation and ethylation at specific sites of Hb with smoking. Because of the low extent of modification of Hb isolated from blood, the methylation and ethylation sites were identified in Hb incubated with a methylating agent (methyl methanesulfonate, MMS) and ethylating agent (ethyl methanesulfonate, EMS), respectively, by accurate mass measurements...
October 12, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/29020440/influence-of-dna-lesions-on-polymerase-mediated-dna-replication-at-single-molecule-resolution
#20
Hailey Gahlon, Louis J Romano, David Rueda
Faithful replication of DNA is a critical aspect in maintaining genome integrity. DNA polymerases are responsible for replicating DNA, and high fidelity polymerases do this rapidly and at low error rates. For example, the holoenzyme of DNA polymerase III in E. coli can replicate at speeds of 600-1,000 bases per second and an error rate of 1 mistake per million nucleotides inserted.1-2 Upon exposure to exogenous or endogenous substances, DNA can become damaged and this can alter the speed and fidelity of a DNA polymerase...
October 11, 2017: Chemical Research in Toxicology
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