keyword
MENU ▼
Read by QxMD icon Read
search

cytochrom p450

keyword
https://www.readbyqxmd.com/read/28102888/genetic-polymorphisms-in-estrogen-metabolic-pathway-associated-with-risks-of-alzheimer-s-disease-evidence-from-a-southern-chinese-population
#1
Lu Hua Chen, Yan Hui Fan, Patrick Yu Ping Kao, Deborah Tip Yin Ho, Joyce Cheuk Tung Ha, Leung Wing Chu, You-Qiang Song
OBJECTIVES: To investigate whether genetic variations on the estrogen metabolic pathway would be associated with risk of Alzheimer's disease (AD). DESIGN: Cross-sectional study. SETTING: Individuals were recruited at the Memory Clinic, Queen Mary Hospital, Hong Kong. PARTICIPANTS: Chinese individuals with (n = 426) and without (n = 350) AD. MEASUREMENTS: All subjects underwent a standardized cognitive assessment and genotyping of four candidate genes on the estrogen metabolic pathway (estrogen receptor α gene (ESR1), estrogen receptor β gene (ESR2), cytochrome P450 19A1 gene (CYP19A1), cytochrome P450 11A1 gene (CYP11A1))...
January 19, 2017: Journal of the American Geriatrics Society
https://www.readbyqxmd.com/read/28101244/celery-extract-inhibits-mouse-cyp2a5-and-human-cyp2a6-activities-via-different-mechanisms
#2
Xiao Deng, Qianghong Pu, Erhao Wang, Chao Yu
Human cytochrome P450 (CYP) 2A6 participates in the metabolism of nicotine and precarcinogens, thus the deliberate inhibition of CYP2A6 may reduce cigarette consumption and therefore reduce the risk of developing the types of cancer associated with smoking. The inhibitory effects and mechanisms of celery (Apium graveolens) extract on mouse CYP2A5 and human CYP2A6 activity remain unclear. These effects were investigated in mouse and human liver microsomes using coumarin 7-hydroxylation in a probe reaction. Celery extract reduced CYP2A5 and CYP2A6 activities in vitro in a dose-dependent manner...
December 2016: Oncology Letters
https://www.readbyqxmd.com/read/28099882/the-35-year-odyssey-of-beta-blockers-in-cirrhosis-any-gender-difference-in-sight
#3
REVIEW
Maria Antonella Burza, Hanns-Ulrich Marschall, Laura Napoleone, Antonio Molinaro
Cirrhosis is the end-stage of chronic liver disease and leads to the development of portal hypertension and its complications such as esophagogastric varices. Non-selective beta blockers (NSBB) are the keystone for the treatment of portal hypertension since the 1980s and, over the decades, several studies have confirmed their beneficial effect on the prevention of variceal (re)bleeding. Pharmacological studies showed effects of gender, sex hormones, oral contraceptives, and pregnancy on cytochrome P450 (CYPs) enzymes that metabolise NSBB, suggesting that gender differences might exist in the effect of NSBB...
January 15, 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/28099803/deep-learning-to-predict-the-formation-of-quinone-species-in-drug-metabolism
#4
Tyler B Hughes, S Joshua Swamidass
Many adverse drug reactions are thought to be caused by electrophilically reactive drug metabolites that conjugate to nucleophilic sites within DNA and proteins, causing cancer or toxic immune responses. Quinone species, including quinone-imines, quinone-methides, and imine-methides, are electrophilic Michael acceptors that are of- ten highly reactive, and comprise over 40% of all known reactive metabolites. Quinone metabolites are created by cytochromes P450 and peroxidases. For example, cy- tochromes P450 oxidize acetaminophen to N-acetyl-p-benzoquinone imine, which is electrophilically reactive and covalently binds to nucleophilic sites within proteins...
January 18, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28099407/effects-of-functional-cyp2c8-cyp2c9-cyp3a5-and-abcb1-genetic-variants-on-the-pharmacokinetics-of-insulin-sensitizer-pioglitazone-in-chinese-han-individuals
#5
Sheng-Ju Yin, Hui-Min Qi, Xin Wang, Pu Zhang, Yuan Lu, Min-Ji Wei, Pu Li, Guang-Zhao Qi, Ya-Qing Lou, Chuang Lu, Guo-Liang Zhang
BACKGROUND AND OBJECTIVES: Pioglitazone is a thiazolidinedione antihyperglycemic drug with insulin-sensitizing properties. We investigated whether the variant genotypes of cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP3A5 and transporter ABCB1 influence the pharmacokinetic phenotype of the substrate pioglitazone in Chinese individuals. PARTICIPANTS AND METHODS: Single-nucleotide polymorphisms were determined by the PCR-restriction fragment length polymorphism method in 244 (CYP2C8 and CYP2C9) healthy Chinese Han individuals...
January 17, 2017: Pharmacogenetics and Genomics
https://www.readbyqxmd.com/read/28098172/structural-diversity-of-anti-pancreatic-cancer-capsimycins-identified-in-mangrove-derived-streptomyces-xiamenensis-318-and-post-modification-via-a-novel-cytochrome-p450-monooxygenase
#6
He-Lin Yu, Shu-Heng Jiang, Xu-Liang Bu, Jia-Hua Wang, Jing-Yi Weng, Xiao-Mei Yang, Kun-Yan He, Zhi-Gang Zhang, Ping Ao, Jun Xu, Min-Juan Xu
Polycyclic tetramate macrolactams (PTMs) were identified as distinct secondary metabolites of the mangrove-derived Streptomyces xiamenensis 318. Together with three known compounds-ikarugamycin (1), capsimycin (2) and capsimycin B (3)-two new compounds, capsimycin C (4) with trans-diols and capsimycin D (5) with trans-configurations at C-13/C-14, have been identified. The absolute configurations of the tert/tert-diols moiety was determined in 4 by NMR spectroscopic analysis, CD spectral comparisons and semi-synthetic method...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28097004/rifampicin-decreases-exposure-to-sublingual-buprenorphine-in-healthy-subjects
#7
Nora M Hagelberg, Mari Fihlman, Tuija Hemmilä, Janne T Backman, Jouko Laitila, Pertti J Neuvonen, Kari Laine, Klaus T Olkkola, Teijo I Saari
Buprenorphine is mainly metabolized by the cytochrome P450 (CYP) 3A4 enzyme. The aim of this study was to evaluate the role of first-pass metabolism in the interaction of rifampicin and analgesic doses of buprenorphine. A four-session paired cross-over study design was used. Twelve subjects ingested either 600 mg oral rifampicin or placebo once daily in a randomized order for 7 days. In the first part of the study, subjects were given 0.6-mg (placebo phase) or 0.8-mg (rifampicin phase) buprenorphine sublingually on day 7...
December 2016: Pharmacology Research & Perspectives
https://www.readbyqxmd.com/read/28095715/an-overview-of-aldehyde-oxidase-an-enzyme-of-emerging-importance-in-novel-drug-discovery
#8
Mohammad-Reza Rashidi, Somaieh Soltani
Given the rising trend in medicinal chemistry strategy to reduce cytochrome P450-dependent metabolism, aldehyde oxidase (AOX) has recently gained increased attention in drug discovery programs and the number of drug candidates that are metabolized by AOX is steadily growing. Areas covered: Despite the emerging importance of AOX in drug discovery, there are certain major recognized problems associated with AOX-mediated metabolism of drugs. Intra- and inter-species variations in AOX activity, the lack of reliable and predictive animal models using the common experimental animals, and failure in the predictions of in vivo metabolic activity of AOX using traditional in vitro methods are among these issues that are covered in this article...
January 17, 2017: Expert Opinion on Drug Discovery
https://www.readbyqxmd.com/read/28094799/activation-of-wnt-%C3%AE-catenin-signalling-via-gsk3-inhibitors-direct-differentiation-of-human-adipose-stem-cells-into-functional-hepatocytes
#9
Jieqiong Huang, Xinyue Guo, Weihong Li, Haiyan Zhang
The generation of hepatocytes that are derived from human adipose stem cells (hASCs) represents an alternative to human hepatocytes for individualized therapeutic and pharmaceutical applications. However, the mechanisms facilitating hepatocyte differentiation from hASCs are not well understood. Here, we show that upon exposure to glycogen synthase kinase 3 (GSK3) inhibitors alone, the expression of definitive endoderm specific genes GATA4, FOXA2, and SOX17 in hASCs significantly increased in a manner with activation of Wnt/β-catenin signalling...
January 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28092943/context-matters-contribution-of-specific-dna-adducts-to-the-genotoxic-properties-of-the-tobacco-specific-nitrosamine-nnk
#10
Lisa A Peterson
The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent pulmonary carcinogen in laboratory animals. It is classified as a Group 1 human carcinogen by the International Agency for Cancer Research. NNK is bioactivated upon cytochrome P450 catalyzed hydroxylation of the carbon atoms adjacent to the nitrosamino group to both methylating and pyridyloxobutylating agents. Both pathways generate a spectrum of DNA damage that contributes to the overall mutagenic and toxic properties of this compound...
January 17, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28091754/a-new-look-at-the-role-of-thiolate-ligation-in-cytochrome-p450
#11
Timothy H Yosca, Aaron P Ledray, Joanna Ngo, Michael T Green
Protonated ferryl (or iron(IV)hydroxide) intermediates have been characterized in several thiolate-ligated heme proteins that are known to catalyze C-H bond activation. The basicity of the ferryl intermediates in these species has been proposed to play a critical role in facilitating this chemistry, allowing hydrogen abstraction at reduction potentials below those that would otherwise lead to oxidative degradation of the enzyme. In this contribution, we discuss the events that led to the assignment and characterization of the unusual iron(IV)hydroxide species, highlighting experiments that provided a quantitative measure of the ferryl basicity, the iron(IV)hydroxide pKa...
January 16, 2017: Journal of Biological Inorganic Chemistry: JBIC
https://www.readbyqxmd.com/read/28089783/characterization-of-rat-or-human-hepatocytes-cultured-in-microphysiological-systems-mps-to-identify-hepatotoxicity
#12
Shih-Yu Chang, Jenna L Voellinger, Kirk P Van Ness, Brian Chapron, Rachel M Shaffer, Thomas Neumann, Collin C White, Terrance J Kavanagh, Edward J Kelly, David L Eaton
The liver is the main site for drug and xenobiotics metabolism, including inactivation or bioactivation. In order to improve the predictability of drug safety and efficacy in clinical development, and to facilitate the evaluation of the potential human health effects from exposure to environmental contaminants, there is a critical need to accurately model human organ systems such as the liver in vitro. We are developing a microphysiological system (MPS) based on a new commercial microfluidic platform (Nortis, Inc...
January 12, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28089731/investigation-of-polymorphisms-in-genes-involved-in-estrogen-metabolism-in-menstrual-migraine
#13
Heidi G Sutherland, Morgane Champion, Amelie Plays, Shani Stuart, Larisa M Haupt, Alison Frith, E Anne MacGregor, Lyn R Griffiths
Migraine is a common, disabling headache disorder, which is influenced by multiple genes and environmental triggers. After puberty, the prevalence of migraine in women is three times higher than in men and >50% of females suffering from migraine report a menstrual association, suggesting hormonal fluctuations can influence the risk of migraine attacks. It has been hypothesized that the drop in estrogen during menses is an important trigger for menstrual migraine. Catechol-O-methyltransferase (COMT) and Cytochrome P450 (CYP) enzymes are involved in estrogen synthesis and metabolism...
January 13, 2017: Gene
https://www.readbyqxmd.com/read/28089686/simulations-of-cytochrome-p450-3a4-mediated-drug-drug-interactions-by-simple-two-compartment-model-assisted-static-method
#14
Katsumi Iga, Akiko Kiriyama
In order to predict cytochrome P450 3A4 (CYP3A4)-mediated drug-drug interactions (DDIs), a simple two-compartment model assisted, overall inhibition-activity (Ai, overall) method was derived based upon two concepts. One concept was that the increase in blood victim-level and fold increase in the area under the blood victim-level curve (AUCR) produced by DDI are determined entirely by Ai, overall, the hepatic availability of the victim and fraction of urinary excreted unchanged victim, where Ai, overall is determined by the perpetrator-specific CYP isoform inhibition activities (Ai,CYPs, DDI predictor-1) and victim-specific fractional CYP isoform contributions (fm,CYPs, predictor-2)...
January 12, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28089047/cypome-of-the-conifer-pathogen-heterobasidion-irregulare-inventory-phylogeny-and-transcriptional-analysis-of-the-response-to-biocontrol
#15
Anthony C Mgbeahuruike, Andriy Kovalchuk, Wimal Ubhayasekera, David R Nelson, Jagjit S Yadav
The molecular mechanisms underlying the interaction of the pathogen, Heterobasidion annosum s.l., the conifer tree and the biocontrol fungus, Phlebiopsis gigantea have not been fully elucidated. Members of the cytochrome P450 (CYP) protein family may contribute to the detoxification of components of chemical defence of conifer trees by H. annosum during infection. Additionally, they may also be involved in the interaction between H. annosum and P. gigantea. A genome-wide analysis of CYPs in Heterobasidion irregulare was carried out alongside gene expression studies...
February 2017: Fungal Biology
https://www.readbyqxmd.com/read/28088650/assessing-the-identity-and-expression-level-of-the-cytochrome-p450-20a1-cyp20a1-gene-in-the-bpa-bde-47-and-waf-exposed-copepods-tigriopus-japonicus-and-paracyclopina-nana
#16
Jeonghoon Han, Duck-Hyun Kim, Jung Soo Seo, Il-Chan Kim, David R Nelson, Jayesh Puthumana, Jae-Seong Lee
CYP20A1 is a member of the cytochrome P450 (CYP) superfamily, identified as an orphan P450 without any assigned biological function; hence, its continued status as an "orphan" gene. In order to address this shortcoming in our understanding of this superfamily, we sought to characterize the CYP20A1 gene in the copepods Tigriopus japonicus (Tj-CYP20A1) and Paracyclopina nana (Pn-CYP20A1) at their mRNA transcriptional level. We assessed the response of this gene's expression in various developmental stages and in response to treatment with bisphenol A (BPA), 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47), and water accommodated fractions (WAFs) of crude oil...
January 11, 2017: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
https://www.readbyqxmd.com/read/28088302/the-cyp79a1-catalyzed-conversion-of-tyrosine-to-e-p-hydroxyphenylacetaldoxime-unravelled-using-an-improved-method-for-homology-modeling
#17
Dario Vazquez-Albacete, Marco Montefiori, Stefan Kol, Mohammed Saddik Motawia, Birger Lindberg Møller, Lars Olsen, Morten H H Nørholm
The vast diversity and membrane-bound nature of plant P450s makes it challenging to study the structural characteristics of this class of enzymes especially with respect to accurate intermolecular enzyme-substrate interactions. To address this problem we here apply a modified hybrid structure strategy for homology modeling of plant P450s. This allows for structural elucidation based on conserved motifs in the protein sequence and secondary structure predictions. We modeled the well-studied Sorghum bicolor cytochrome P450 CYP79A1 catalyzing the first step in the biosynthesis of the cyanogenic glucoside dhurrin...
January 11, 2017: Phytochemistry
https://www.readbyqxmd.com/read/28087752/deficient-retinoid-driven-angiogenesis-may-contribute-to-failure-of-adult-human-lung-regeneration-in-emphysema
#18
John-Poul Ng-Blichfeldt, Joana Alçada, M Angeles Montero, Charlotte H Dean, Uta Griesenbach, Mark J Griffiths, Matthew Hind
BACKGROUND: Molecular pathways that regulate alveolar development and adult repair represent potential therapeutic targets for emphysema. Signalling via retinoic acid (RA), derived from vitamin A, is required for mammalian alveologenesis, and exogenous RA can induce alveolar regeneration in rodents. Little is known about RA signalling in the human lung and its potential role in lung disease. OBJECTIVES: To examine regulation of human alveolar epithelial and endothelial repair by RA, and characterise RA signalling in human emphysema...
January 13, 2017: Thorax
https://www.readbyqxmd.com/read/28087463/effect-of-22-cyp2d6-variants-found-in-the-chinese-population-on-tolterodine-metabolism-in-vitro
#19
Hao Wang, Da-Peng Dai, Peng Sun, Li-Ping Xu, Bing-Qing Liang, Jian-Ping Cai, Guo-Xin Hu
Cytochrome P450 2D6 (CYP2D6) is an important member of the cytochrome P450 enzyme superfamily. We recently identified 22 novel variants in the Chinese population using PCR and bidirectional sequencing methods. The aim of this study is to characterize the enzymatic activity of these variants and their effects on the metabolism of the antimuscarinic drug tolterodine in vitro. A baculovirus-mediated expression system was used to express wild-type CYP2D6 and 24 variants (CYP2D6*2, CYP2D6*10, and 22 novel CYP2D6 variants) at high levels...
January 10, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28086840/evidence-of-multiple-insecticide-resistance-mechanisms-in-anopheles-gambiae-populations-in-bangui-central-african-republic
#20
Marina Lidwine Olé Sangba, Aboubakar Sidick, Renaud Govoetchan, Christian Dide-Agossou, Razaki A Ossè, Martin Akogbeto, Mamadou Ousmane Ndiath
BACKGROUND: Knowledge of insecticide resistance status in the main malaria vectors is an essential component of effective malaria vector control. This study presents the first evaluation of the status of insecticide resistance in Anopheles gambiae populations from Bangui, the Central African Republic. METHODS: Anopheles mosquitoes were reared from larvae collected in seven districts of Bangui between September to November 2014. The World Health Organisation's bioassay susceptibility tests to lambda-cyhalothrin (0...
January 13, 2017: Parasites & Vectors
keyword
keyword
100850
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"