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Allemang A, Lester C, Roth T, Pfuhler S, Peuschel H, Kosemund K, Mahony C, Bergeland T, O'Keeffe L. Assessing the genotoxicity and carcinogenicity of 2-chloroethanol through structure activity relationships and in vitro testing approaches. Food Chem Toxicol 2022; 168:113290. [PMID: 35863484 DOI: 10.1016/j.fct.2022.113290] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/16/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022]
Abstract
The detection of 2-chloroethanol in foods generally follows an assumption that the pesticide ethylene oxide has been used at some stage in the supply chain. In this situation the Pesticide Residues in Food Regulation (EC) 396/2005 requires 2-chloroethanol to be assessed as if equivalent to ethylene oxide, which has been classified as a genotoxic carcinogen. This review investigated whether this is an appropriate risk assessment approach for 2-chloroethanol. This involved an assessment of existing genotoxicity and carcinogenicity data, application of Structure Activity Based Read Across for carcinogenicity assessment, biological reactivity in the ToxTracker assay and micronuclei formation in HepaRG cells. Although we identified there is an absence of a standard oral bioassay for 2-chloroethanol, carcinogenicity weight-of-evidence assessment along with data on relevant structural analogues do not show evidence for carcinogenicity for 2-chloroethanol. The absence of genotoxicity was demonstrated for 2-chloroethanol and suitable analogues. In contrast, ethylene oxide showed reactivity towards markers indicative of direct DNA damage which is consistent with what is known about its mode-of-action. These data facilitate the understanding of 2-chloroethanol and given that it is not a genotoxic carcinogen suggest it must be assessed relative to non-cancer endpoints and a health protective Reference Dose should be established on that basis.
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Affiliation(s)
| | - Cathy Lester
- The Procter & Gamble Company, Cincinnati, OH, USA
| | - Thomas Roth
- SCC Scientific Consulting Company GmbH, Am Grenzgraben 11, 55545, Bad Kreuznach, Germany
| | | | - Henrike Peuschel
- SCC Scientific Consulting Company GmbH, Am Grenzgraben 11, 55545, Bad Kreuznach, Germany
| | - Kirstin Kosemund
- Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65824, Schwalbach am Taunus, Germany
| | | | | | - Lara O'Keeffe
- The Procter & Gamble Company, Reading, Berkshire, UK.
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2
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Colldén H, Landin A, Wallenius V, Elebring E, Fändriks L, Nilsson ME, Ryberg H, Poutanen M, Sjögren K, Vandenput L, Ohlsson C. The gut microbiota is a major regulator of androgen metabolism in intestinal contents. Am J Physiol Endocrinol Metab 2019; 317:E1182-E1192. [PMID: 31689143 PMCID: PMC6962501 DOI: 10.1152/ajpendo.00338.2019] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Androgens exert important effects both in androgen-responsive tissues and in the intestinal tract. To determine the impact of the gut microbiota (GM) on intestinal androgen metabolism, we measured unconjugated (free) and glucuronidated androgen levels in intestinal contents from the small intestine, with a low bacterial density, and from cecum and colon, with a high bacterial density. Using a specific, sensitive gas chromatography-tandem mass spectrometry method, we detected high levels of glucuronidated testosterone (T) and dihydrotestosterone (DHT) in small intestinal content of mice of both sexes, whereas in the distal intestine we observed remarkably high levels of free DHT, exceeding serum levels by >20-fold. Similarly, in young adult men high levels of unconjugated DHT, >70-fold higher than in serum, were detected in feces. In contrast to mice with a normal GM composition, germ-free mice had high levels of glucuronidated T and DHT, but very low free DHT levels, in the distal intestine. These findings demonstrate that the GM is involved in intestinal metabolism and deglucuronidation of DHT and T, resulting in extremely high free levels of the most potent androgen, DHT, in the colonic content of young and healthy mice and men.
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Affiliation(s)
- Hannah Colldén
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andreas Landin
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ville Wallenius
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Erik Elebring
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lars Fändriks
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Maria E Nilsson
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Henrik Ryberg
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Matti Poutanen
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Biomedicine, Research Centre for Integrative Physiology and Pharmacology and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Klara Sjögren
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Liesbeth Vandenput
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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3
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Hatley OJD, Jones CR, Galetin A, Rostami-Hodjegan A. Optimization of intestinal microsomal preparation in the rat: A systematic approach to assess the influence of various methodologies on metabolic activity and scaling factors. Biopharm Drug Dispos 2017; 38:187-208. [PMID: 28207929 PMCID: PMC5413848 DOI: 10.1002/bdd.2070] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/31/2017] [Accepted: 02/11/2017] [Indexed: 01/27/2023]
Abstract
The metabolic capacity of the intestine and its importance as the initial barrier to systemic exposure can lead to underestimation of first‐pass, and thus overestimation of oral bioavailability. However, the in vitro tools informing estimates of in vivo intestinal metabolism are limited by the complexity of the in vitro matrix preparation and uncertainty with the scaling factors for in vitro to in vivo extrapolation. A number of methods currently exist in the literature for the preparation of intestinal microsomes; however, the impact of key steps in the preparation procedure has not been critically assessed. In the current study, changes in enterocyte isolation, the impact of buffer constituents heparin and glycerol, as well as sonication as a direct method of homogenization were assessed systematically. Furthermore, fresh vs. frozen tissue samples and the impact of microsome freeze thawing was assessed. The rat intestinal microsomes were characterized for CYP content as well as metabolic activity using testosterone and 4‐nitropheonol as probes for CYP and UGT activity, respectively. Comparisons in metabolic activity and scaled unbound intestinal intrinsic clearance (CLintu,gut) were made to commercially available microsomes using 25 drugs with a diverse range of metabolic pathways and intestinal metabolic stabilities. An optimal, robust and reproducible microsomal preparation method for investigation of intestinal metabolism is proposed. The importance of characterization of the in vitro matrix and the potential impact of intestinal scaling factors on the in vitro–in vivo extrapolation of FG needs to be investigated further. © 2017 The Authors Biopharmaceutics & Drug Disposition Published by John Wiley & Sons Ltd.
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Affiliation(s)
- Oliver J D Hatley
- Certara, Blades Enterprise Centre, Sheffield, S2 4SU, UK.,Centre for Applied Pharmacokinetic Research, University of Manchester, Manchester, M13 9PT, UK
| | | | - Aleksandra Galetin
- Centre for Applied Pharmacokinetic Research, University of Manchester, Manchester, M13 9PT, UK
| | - Amin Rostami-Hodjegan
- Certara, Blades Enterprise Centre, Sheffield, S2 4SU, UK.,Centre for Applied Pharmacokinetic Research, University of Manchester, Manchester, M13 9PT, UK
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4
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Peters SA, Jones CR, Ungell AL, Hatley OJD. Predicting Drug Extraction in the Human Gut Wall: Assessing Contributions from Drug Metabolizing Enzymes and Transporter Proteins using Preclinical Models. Clin Pharmacokinet 2016; 55:673-96. [PMID: 26895020 PMCID: PMC4875961 DOI: 10.1007/s40262-015-0351-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intestinal metabolism can limit oral bioavailability of drugs and increase the risk of drug interactions. It is therefore important to be able to predict and quantify it in drug discovery and early development. In recent years, a plethora of models-in vivo, in situ and in vitro-have been discussed in the literature. The primary objective of this review is to summarize the current knowledge in the quantitative prediction of gut-wall metabolism. As well as discussing the successes of current models for intestinal metabolism, the challenges in the establishment of good preclinical models are highlighted, including species differences in the isoforms; regional abundances and activities of drug metabolizing enzymes; the interplay of enzyme-transporter proteins; and lack of knowledge on enzyme abundances and availability of empirical scaling factors. Due to its broad specificity and high abundance in the intestine, CYP3A is the enzyme that is frequently implicated in human gut metabolism and is therefore the major focus of this review. A strategy to assess the impact of gut wall metabolism on oral bioavailability during drug discovery and early development phases is presented. Current gaps in the mechanistic understanding and the prediction of gut metabolism are highlighted, with suggestions on how they can be overcome in the future.
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Affiliation(s)
- Sheila Annie Peters
- Translational Quantitative Pharmacology, BioPharma, R&D Global Early Development, Merck KGaA, Frankfurter Str. 250, F130/005, 64293, Darmstadt, Germany.
| | | | - Anna-Lena Ungell
- Investigative ADME, Non-Clinical Development, UCB New Medicines, BioPharma SPRL, Braine l'Alleud, Belgium
| | - Oliver J D Hatley
- Simcyp Limited (A Certara Company), Blades Enterprise Centre, Sheffield, UK
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5
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Shi R, Ma B, Wu J, Wang T, Ma Y. Rapid and accurate liquid chromatography and tandem mass spectrometry method for the simultaneous quantification of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes. J Sep Sci 2015; 38:3363-73. [DOI: 10.1002/jssc.201500418] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/03/2015] [Accepted: 07/21/2015] [Indexed: 12/23/2022]
Affiliation(s)
- Rong Shi
- Department of Pharmacology; Shanghai University of Traditional Chinese Medicine; Shanghai China
| | - Bingliang Ma
- Department of Pharmacology; Shanghai University of Traditional Chinese Medicine; Shanghai China
| | - Jiasheng Wu
- Department of Pharmacology; Shanghai University of Traditional Chinese Medicine; Shanghai China
| | - Tianming Wang
- Department of Pharmacology; Shanghai University of Traditional Chinese Medicine; Shanghai China
| | - Yueming Ma
- Department of Pharmacology; Shanghai University of Traditional Chinese Medicine; Shanghai China
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6
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Huang Y, Hu N, Gao X, Yan Z, Li S, Jing W, Yan R. Alterations of testosterone metabolism in microsomes from rats with experimental colitis induced by dextran sulfate sodium. Chem Biol Interact 2015; 232:38-48. [DOI: 10.1016/j.cbi.2015.02.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 02/13/2015] [Accepted: 02/17/2015] [Indexed: 01/22/2023]
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7
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Ye N, Tang M, Ye H, Wang C, Wang C, Yang Q, Wan L, Chen L. 13C stable isotope labeling followed by ultra-high performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF MS) was applied to identify the metabolites of honokiol in rat small intestines. ANALYTICAL METHODS 2015. [DOI: 10.1039/c4ay02403f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Honokiol, as a pharmacological active small-molecule, has received significant attention for its strong pharmacological effects without remarkable toxicity.
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Affiliation(s)
- Na Ye
- School of Pharmacy
- Chengdu University of TCM
- The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
| | - Minghai Tang
- State Key Laboratory of Biotherapy
- West China Hospital
- West China Medical School
- Sichuan University
- Chengdu 610041
| | - Haoyu Ye
- State Key Laboratory of Biotherapy
- West China Hospital
- West China Medical School
- Sichuan University
- Chengdu 610041
| | - Chunyan Wang
- School of Pharmacy
- Chengdu University of TCM
- The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
| | - Chunyu Wang
- State Key Laboratory of Biotherapy
- West China Hospital
- West China Medical School
- Sichuan University
- Chengdu 610041
| | - Qiunan Yang
- School of Pharmacy
- Chengdu University of TCM
- The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
| | - Li Wan
- School of Pharmacy
- Chengdu University of TCM
- The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
| | - Lijuan Chen
- State Key Laboratory of Biotherapy
- West China Hospital
- West China Medical School
- Sichuan University
- Chengdu 610041
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Tzankova V, Ivanova C, Dragoni S, Danchev N, Valoti M. Precision-Cut Slices as a Tool for Studying Phase II Drug Metabolism in Rat Small Intestinein Vitro. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.5504/bbeq.2011.0002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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9
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Gundert-Remy U, Bernauer U, Blömeke B, Döring B, Fabian E, Goebel C, Hessel S, Jäckh C, Lampen A, Oesch F, Petzinger E, Völkel W, Roos PH. Extrahepatic metabolism at the body's internal–external interfaces. Drug Metab Rev 2014; 46:291-324. [DOI: 10.3109/03602532.2014.900565] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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10
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Bagul P, Khomane KS, Bansal AK. Investigating permeability related hurdles in oral delivery of 11-keto-β-boswellic acid. Int J Pharm 2014; 464:104-10. [PMID: 24463070 DOI: 10.1016/j.ijpharm.2014.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/09/2014] [Accepted: 01/10/2014] [Indexed: 01/15/2023]
Abstract
11-Keto-β-boswellic acid (KBA) is an important and potent boswellic acids responsible for anti-inflammatory action of Boswellia extract. However, its pharmaceutical development has been severely limited by its poor oral bioavailability. The present work aims to investigate the permeability related hurdles in oral delivery of KBA. Gastrointestinal stability, gastrointestinal metabolism, adsorption-desorption kinetics and Caco-2 permeability studies have been carried out. KBA was found poorly permeable with Papp value of 2.85 ± 0.14 × 10(-6)cm/s. Higher absorptive transport indicated role of carrier mediated transport. Moreover, KBA transport across monolayer showed saturation kinetics at higher concentrations. KBA exposed to 1α,25-(OH)2 vitamin D3 treated cell monolayer showed the lowest Papp value of 2.01×10(-6) ± 0.02 × 10(-6)cm/s indicating role of CYP3A4 mediated metabolism during KBA transport. Metabolic stability experiments in jejunum S9 fractions further confirmed this. KBA was found unstable in simulated gastrointestinal fluids and also got accumulated in the enterocytes. Sorption and desorption kinetic studies using Caco-2 cells further confirmed accumulation of KBA inside the enterocytes. KBA also showed pH dependent permeability with higher flux at gradient pH condition of pH 6.5 at apical and 7.4 at basolateral. Taken as whole, the major permeability related hurdles that hampered oral bioavailability of KBA included its gastrointestinal instability, CYP3A4 mediated intestinal metabolism, accumulation within the enterocytes and saturable kinetics. The present investigation may help in designing novel drug delivery system for KBA.
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Affiliation(s)
- Pravin Bagul
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Mohali, Punjab 160 062, India
| | - Kailas S Khomane
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Mohali, Punjab 160 062, India
| | - Arvind K Bansal
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Mohali, Punjab 160 062, India.
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van de Kerkhof EG, de Graaf IAM, de Jager MH, Meijer DKF, Groothuis GMM. CHARACTERIZATION OF RAT SMALL INTESTINAL AND COLON PRECISION-CUT SLICES AS AN IN VITRO SYSTEM FOR DRUG METABOLISM AND INDUCTION STUDIES. Drug Metab Dispos 2005; 33:1613-20. [PMID: 16051733 DOI: 10.1124/dmd.105.005686] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to characterize rat small intestinal and colon tissue slices as a tool to study intestinal metabolism and to investigate gradients of drug metabolism along the intestinal tract as well as drug-induced inhibition and induction of biotransformation. Tissue morphology and the intestinal mucus layer remained intact in small intestinal and colon slices during 3 h of incubation, while alkaline phosphatase was retained and the rate of metabolism of three model compounds (7-hydroxycoumarin, 7-ethoxycoumarin, and testosterone) appeared constant. Phase I and phase II metabolic gradients, decreasing from stomach toward colon were shown to be clearly different for the model compounds used. Furthermore, the observed slice activities were similar or even higher compared with the literature data concerning metabolism of in vitro intestinal systems. Preincubation with beta-naphthoflavone for 24 h induced the O-deethylation of 7-ethoxycoumarin from nearly undetectable to 140 pmol/min/mg protein in small intestine (fresh slices, 43 pmol/min/mg protein) and to 100 pmol/min/mg protein in colon slices (fresh slices, undetectable). Ketoconazole inhibited metabolism of testosterone by 40% and that of 7-ethoxycoumarin by 100%. In conclusion, we showed that the intestinal slice model is an excellent model to study drug metabolism in the intestine in vitro, since we found that the viability parameters remain constant and the measured enzyme activities are relevant, sensitive to inhibitors, and inducible. Therefore, it is a promising tool to study intestinal drug metabolism in human intestine in vitro in the future.
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Affiliation(s)
- Esther G van de Kerkhof
- Department of Pharmacokinetics & Drug Delivery, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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