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https://www.readbyqxmd.com/read/29331654/in-vitro-and-in-vivo-metabolic-activation-of-rhein-and-characterization-of-glutathione-conjugates-derived-from-rhein
#1
Yang Xu, Xu Mao, Boyang Qin, Ying Peng, Jiang Zheng
Rhein (RH), 4,5-dihydroxyanthrauinone-2-carboxylic acid, is found in rhubarb (Dahuang), a traditional herbal medicine. RH has reportedly demonstrated multiple pharmacologic properties. Previous studies have also shown that RH induced hepatotoxicity, but the mechanisms of the adverse effect remain unknown. The major objective of the present study was to study the metabolic pathways of RH in order to identify potential reactive metabolites. One mono-hydroxylation metabolite (M1) was detected in urine and bile of rats given RH...
January 10, 2018: Chemico-biological Interactions
https://www.readbyqxmd.com/read/29330881/cocaine-and-hiv-1-tat-disrupt-cholesterol-homeostasis-in-astrocytes-implications-for-hiv-associated-neurocognitive-disorders-in-cocaine-user-patients
#2
Bianca Cotto, Kalimuthusamy Natarajaseenivasan, Kimberly Ferrero, Leroy Wesley, Matthew Sayre, Dianne Langford
Cholesterol synthesis and clearance by astrocytes are tightly regulated to maintain constant levels within the brain. In this context, liver X receptors (LXRs) are the master regulators of cholesterol homeostasis in the central nervous system (CNS). Increasing levels of cholesterol in astrocytes trigger LXR activation leading to the transcription of target genes involved in cholesterol trafficking and efflux, including apolipoprotein E, cytochrome P450 enzymes, sterol regulatory binding protein, and several ATP-binding cassette transporter proteins...
January 13, 2018: Glia
https://www.readbyqxmd.com/read/29330782/characterization-of-the-pharmacokinetics-of-vilaprisan-bioavailability-excretion-biotransformation-and-drug-drug-interaction-potential
#3
Marcus-Hillert Schultze-Mosgau, Joachim Höchel, Olaf Prien, Torsten Zimmermann, Ashley Brooks, Jim Bush, Antje Rottmann
BACKGROUND AND OBJECTIVES: In-vitro data suggest that clearance of vilaprisan is mediated by cytochrome P450 3A4 (oxidation) and aldoketoreductases (reduction). To fully understand the elimination and biotransformation pathways of vilaprisan, a selective progesterone receptor modulator, and to quantify the impact of cytochrome P450 3A4 inhibition on the pharmacokinetics of vilaprisan, two clinical studies in healthy postmenopausal women were conducted. METHODS: In study 1, pharmacokinetics, mass balance, and metabolite patterns were determined after single oral administration of 5 mg of [14C]-labeled vilaprisan in six subjects...
January 12, 2018: Clinical Pharmacokinetics
https://www.readbyqxmd.com/read/29330715/case-series-analysis-of-new-zealand-reports-of-rapid-intense-potentiation-of-warfarin-by-roxithromycin
#4
Ruth L Savage, Michael V Tatley
INTRODUCTION: We undertook an analysis of all the reports to the New Zealand Centre for Adverse Reactions Monitoring of a roxithromycin/warfarin interaction after two recent reports described intense rapid warfarin potentiation. The interaction was first published in 1995. Cytochrome P450 3A4 inhibition has been the proposed mechanism but has limited biologic plausibility. There are suggestions that the clinical significance of the interaction may be increased by severe illness, polypharmacy, renal dysfunction, older age and increased warfarin sensitivity...
January 12, 2018: Drug Safety: An International Journal of Medical Toxicology and Drug Experience
https://www.readbyqxmd.com/read/29330355/fatty-acids-and-related-lipid-mediators-in-the-regulation-of-cutaneous-inflammation
#5
REVIEW
Magdalena Kiezel-Tsugunova, Alexandra C Kendall, Anna Nicolaou
Human skin has a distinct profile of fatty acids and related bioactive lipid mediators that regulate many aspects of epidermal and dermal homeostasis, including immune and inflammatory reactions. Sebum lipids act as effective antimicrobial agents, shape immune cell communications and contribute to the epidermal lipidome. The essential fatty acid linoleic acid is crucial for the structure of the epidermal barrier, while polyunsaturated fatty acids act as precursors to eicosanoids, octadecanoids and docosanoids through cyclooxygenase, lipoxygenase and cytochrome P450 monooxygenase-mediated reactions, and endocannabinoids and N-acyl ethanolamines...
January 12, 2018: Biochemical Society Transactions
https://www.readbyqxmd.com/read/29330218/a-study-on-pharmacokinetics-of-bosentan-with-systems-modeling-part-1-translating-systemic-plasma-concentration-to-liver-exposure-in-healthy-subjects
#6
Rui Li, Mark Niosi, Nathaniel Johnson, David A Tess, Emi Kimoto, Jian Lin, Xin Yang, Keith A Riccardi, Sangwoo Ryu, Ayman F El-Kattan, Tristan S Maurer, Larry M Tremaine, Li Di
Understanding liver exposure of hepatic transporter substrates in clinical studies is often critical as it typically governs pharmacodynamics, drug-drug interactions, and toxicity for certain drugs. However, this is a challenging task since there is currently no easy method to directly measure drug concentration in the human liver. Using bosentan as an example, a new approach has been demonstrated to estimate liver exposure based on observed systemic pharmacokinetics from clinical studies using physiologically-based pharmacokinetic modeling...
January 12, 2018: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/29329665/bioactivation-of-1-chloro-2-hydroxy-3-butene-an-in-vitro-metabolite-of-1-3-butadiene-by-rat-liver-microsomes
#7
Ye Wang, Ying-Xin Yu, Yang Luan, Jing An, Dong-Guang Yin, Xin-Yu Zhang
1-Chloro-2-hydroxy-3-butene (CHB) is an in vitro metabolite of 1,3-butadiene, a rodent/human carcinogen. To search for an approach detecting CHB in vivo, it is vital to obtain a full understanding of CHB metabolism. Previously, we demonstrated that CHB was bioactivated to 1-chloro-3-buten-2-one (CBO) by alcohol dehydrogenase. However, CHB metabolism by cytochrome P450s has not been reported. Thus, in the present study, CHB metabolism by rat liver microsomes was investigated. The results showed that CHB was converted to 1-chloro-3,4-epoxy-2-butanol (CEB) and CBO...
January 9, 2018: Chemico-biological Interactions
https://www.readbyqxmd.com/read/29329342/ternary-copper-ii-complex-nci60-screening-toxicity-studies-and-evaluation-of-efficacy-in-xenograft-models-of-nasopharyngeal-carcinoma
#8
Munirah Ahmad, Shazlan-Noor Suhaimi, Tai-Lin Chu, Norazlin Abdul Aziz, Noor-Kaslina Mohd Kornain, D S Samiulla, Kwok-Wai Lo, Chew-Hee Ng, Alan Soo-Beng Khoo
Copper(II) ternary complex, [Cu(phen)(C-dmg)(H2O)]NO3 was evaluated against a panel of cell lines, tested for in vivo efficacy in nasopharyngeal carcinoma xenograft models as well as for toxicity in NOD scid gamma mice. The Cu(II) complex displayed broad spectrum cytotoxicity against multiple cancer types, including lung, colon, central nervous system, melanoma, ovarian, and prostate cancer cell lines in the NCI-60 panel. The Cu(II) complex did not cause significant induction of cytochrome P450 (CYP) 3A and 1A enzymes but moderately inhibited CYP isoforms 1A2, 2C9, 2C19, 2D6, 2B6, 2C8 and 3A4...
2018: PloS One
https://www.readbyqxmd.com/read/29328974/novel-approach-for-evaluating-pharmaceuticals-toxicity-using-daphnia-model-analysis-of-the-mode-of-cytochrome-p450-generated-metabolite-action-after-acetaminophen-exposure
#9
Ryeo-Ok Kim, Min-A Jo, Jinhaeng Song, Il-Chan Kim, Seokjoo Yoon, Woo-Keun Kim
Because of its widespread use, the pharmaceutical acetaminophen (APAP) is frequently detected in aquatic environments. APAP can have serious physiological effects, such as reduced reproduction, low growth rates, and abnormal behavior, in aquatic organisms. However, the methods available for evaluation of the aquatic toxicity of APAP are of limited usefulness. The present study aimed to develop reliable and sensitive markers for evaluation of APAP toxicity using Daphnia as a model organism. We focused on N-acetyl-p-benzoquinoneimine (NAPQI) production from APAP via cytochrome P450 metabolism because NAPQI causes APAP toxicity...
December 30, 2017: Aquatic Toxicology
https://www.readbyqxmd.com/read/29328413/prevalence-of-the-cyp2c19-2-681-g-a-3-636-g-a-and-17-%C3%A2-806-c-t-alleles-among-an-iranian-population-of-different-ethnicities
#10
Mahshid Dehbozorgi, Behnam Kamalidehghan, Iman Hosseini, Zahra Dehghanfard, Mohammad Hossein Sangtarash, Maryam Firoozi, Fatemeh Ahmadipour, Goh Yong Meng, Massoud Houshmand
Polymorphisms in the cytochrome P (CYP) 450 family may cause adverse drug responses in individuals. Cytochrome P450 2C19 (CYP2C19) is a member of the CYP family, where the presence of the 681 G>A, 636 G>A and 806 C>T polymorphisms result in the CYP2C19*2, CYP2C19*3 and CYP2C19*17 alleles, respectively. In the current study, the frequency of the CYP2C19*2, CYP2C19*3 and CYP2C19*17 alleles in an Iranian population cohort of different ethnicities were examined and then compared with previously published frequencies within other populations...
January 5, 2018: Molecular Medicine Reports
https://www.readbyqxmd.com/read/29328376/identification-of-a-novel-compound-heterozygous-mutation-of-the-cyp21a2-gene-causing-21%C3%A2-hydroxylase-deficiency-in-a-chinese-pedigree
#11
Jia Liu, Xiujuan Zhang, Haiqing Zhang, Li Fang, Jin Xu, Qingbo Guan, Chao Xu
21‑Hydroxylase deficiency (21‑OHD) is the most common cause of congenital adrenal hyperplasia. Inherited in an autosomal recessive manner, 21‑OHD is caused by mutations in the cytochrome P450 family 21 subfamily A member 2 (CYP21A2) gene. The present study was designed to investigate the genetic characteristics of one Chinese pedigree and to identify the genotype‑phenotype association, thereby facilitating the precise diagnosis of 21‑OHD at the molecular level. Members of a Chinese family with 21‑OHD were screened for mutations in the CYP21A2 gene...
January 8, 2018: Molecular Medicine Reports
https://www.readbyqxmd.com/read/29327817/ketonization-of-proline-residues-in-the-peptide-chains-of-actinomycins-by-a-4-oxoproline-synthase
#12
Siamak Semsary, Ivana Crnovčić, Ronja Driller, Joachim Vater, Bernhard Loll, Ullrich Keller
X-type actinomycins (Acms) contain 4-hydroxyproline (Acm X0) or 4-oxoproline (Acm X2) in their ß-pentapeptide lactone rings whereas their α-ring contains proline. We demonstrate that these Acms are formed through asymmetric condensation of Acm half molecules (Acm halves) containing proline with 4-hydroxyproline- or 4-oxo-proline-containing Acm halves. In turn we show - using an artificial Acm half analogue (PPL 1) with proline in its peptide chain - its conversion into the 4-hydroxyproline and 4-oxoproline-containing Acm halves, PPL 0 and PPL 2, in mycelial suspensions of Streptomyces antibioticus...
January 12, 2018: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/29327633/biochemical-basis-for-the-age-related-sensitivity-of-broilers-to-aflatoxin-b1
#13
He Wang, Wei Li, Ishfaq Muhammad, Xiaoqi Sun, Xiaoxu Cui, Ping Cheng, Qayum Abdul, Xiuying Zhang
In this study, we investigated the mechanism underlying age-related susceptibility in broilers to aflatoxin B1 (AFB1). The results showed that AFB1 induced significant changes in serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) activity & liver superoxide dismutase (SOD), malonaldehyde (MDA), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST) activity at day 7, 21 and 42 relative to control group. However, AFB1-induced changes in serum biochemical parameters and liver antioxidant activities becomes less severe with increasing age of broilers...
January 12, 2018: Toxicology Mechanisms and Methods
https://www.readbyqxmd.com/read/29327353/increased-risk-of-congestive-heart-failure-in-patients-with-acetaminophen-poisoning-a-nationwide-cohort-study
#14
Wei-Sheng Chung, Cheng-Li Lin
Acetaminophen poisoning increases cytochrome P450 2E1 expression and reactive oxygen species production, which may lead to maladaptive myocardial remodeling and congestive heart failure (CHF). We conducted a nationwide cohort study to investigate the incidence and risk of CHF in patients with acetaminophen poisoning. We identified a cohort of adult patients with newly diagnosed acetaminophen poisoning in the inpatient claims of the Taiwan National Health Insurance Research Database for the 1998-2011 period...
January 11, 2018: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/29327113/storage-stability-study-of-porcine-hepatic-and-intestinal-cytochrome-p450-isoenzymes-by-use-of-a-newly-developed-and-fully-validated-highly-sensitive-hplc-ms-ms-method
#15
Wim Schelstraete, Mathias Devreese, Siska Croubels
Microsomes are an ideal medium to investigate cytochrome P450 (CYP450) enzyme-mediated drug metabolism. However, before microsomes are prepared, tissues can be stored for a long time. Studies about the stability of these enzymes in porcine hepatic and intestinal tissues upon storage are lacking. To be able to investigate CYP450 stability in microsomes prepared from these tissues, a highly sensitive and rapid HPLC-MS/MS method for the simultaneous determination of six CYP450 metabolites in incubation medium was developed and validated...
January 11, 2018: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29326811/impact-of-liver-volume-and-liver-function-on-posthepatectomy-liver-failure-after-portal-vein-embolization-a-multivariable-cohort-analysis
#16
Patrick H Alizai, Annabel Haelsig, Philipp Bruners, Florian Ulmer, Christian D Klink, Cornelis H C Dejong, Ulf P Neumann, Maximilian Schmeding
Background: Liver failure remains a life-threatening complication after liver resection, and is difficult to predict preoperatively. This retrospective cohort study evaluated different preoperative factors in regard to their impact on posthepatectomy liver failure (PHLF) after extended liver resection and previous portal vein embolization (PVE). Methods: Patient characteristics, liver function and liver volumes of patients undergoing PVE and subsequent liver resection were analyzed...
January 2018: Annals of Medicine and Surgery
https://www.readbyqxmd.com/read/29326367/organic-anion-transporter-2-mediates-hepatic-uptake-of-tolbutamide-a-cytochrome-p450-2c9-probe-drug
#17
Yi-An Bi, Sumathy Mathialagan, Laurie Tylaska, Myra Fu, Julie Keefer, Anna Vildhede, Chester Costales, A David Rodrigues, Manthena Varma
Tolbutamide is primarily metabolized by cytochrome P450 (CYP)2C9, and thus, frequently applied as a clinical probe substrate for CYP2C9 activity. However, there is a marked discrepancy in the in vitro-in vivo extrapolation of its metabolic clearance implying potential for additional clearance mechanisms. The goal of this study was to evaluate the role of hepatic uptake transport in the pharmacokinetics of tolbutamide and identify the molecular mechanism thereof. Transport studies using singly-transfected cells expressing six major hepatic uptake transporters showed that tolbutamide is a substrate to organic anion transporter (OAT)2 alone -- with transporter affinity (Km) of 19...
January 11, 2018: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/29326229/genomic-understanding-of-an-infectious-brain-disease-from-the-desert
#18
Leandro F Moreno, Abdalla A O Ahmed, Balázs Brankovics, Christina A Cuomo, Steph B J Menken, Saad J Taj-Aldeen, Hani Faidah, J Benjamin Stielow, Marcus de M Teixeira, Francesc X Prenafeta-Boldú, Vania A Vicente, Sybren de Hoog
Rhinocladiella mackenziei accounts for the majority of fungal brain infections in the Middle East and is restricted to the arid climate zone between Saudi Arabia and Pakistan. Neurotropic dissemination caused by this fungus has been reported in immunocompromised, but also immunocompetent individuals. If untreated, the infection is fatal. Outside of humans, the environmental niche of R. mackenziei is unknown, and the fungus has been only cultured from brain biopsies. In this paper we describe the whole genome re-sequencing of two Rhinocladiella mackenziei strains from patients in Saudi Arabia and Qatar...
January 11, 2018: G3: Genes—Genomes—Genetics
https://www.readbyqxmd.com/read/29325731/pharmacogenomic-testing-in-child-and-adolescent-psychiatry-an-evidence-based-review
#19
Anna M Wehry, Laura Ramsey, Shane E Dulemba, Sarah A Mossman, Jeffrey R Strawn
Significant advances have been made in the application of pharmacogenomic testing for the treatment of patients with psychiatric disorders. Over the past decade, a number of studies have evaluated the utility of pharmacogenomic testing in pediatric patients with psychiatric disorders. The evidence base for pharmacogenomic testing in youth with depressive and anxiety disorders as well as attention/deficit hyperactivity disorder (ADHD) is reviewed in this article. General pharmacogenomic principles are summarized and functional polymorphisms in P450 enzymes (and associated metabolizer phenotypes), the serotonin transporter promoter polymorphisms, serotonin 2 A receptor genes (e...
January 8, 2018: Current Problems in Pediatric and Adolescent Health Care
https://www.readbyqxmd.com/read/29325225/influence-of-cyp2d6-cyp3a4-cyp3a5-and-abcb1-polymorphisms-on-pharmacokinetics-and-safety-of-aripiprazole-in-healthy-volunteers
#20
Carmen Belmonte, Dolores Ochoa, Manuel Román, Miriam Saiz-Rodríguez, Aneta Wojnicz, Clara Isabel Gómez-Sánchez, Samuel Martín-Vilchez, Francisco Abad-Santos
The aim of this study was to investigate the effect of polymorphisms in cytochrome P450 (CYP) 2D6, CYP3A4 and CYP3A5 enzymes and in P-glycoprotein (P-gp) on the pharmacokinetics and safety of aripiprazole and, its active metabolite, dehydro-aripiprazole, in 148 healthy volunteers from 6 bioequivalence trials receiving a single oral dose of aripiprazole. The plasma concentrations of both analytes were measured by LC-MS/MS. CYP2D6 (*3,*4,*5,*6,*7,*9 and copy number variations), CYP3A4 (*20 and *22), CYP3A5*3 and C3435T, C1236T and G2677T/A in ABCB1 gene were determined...
January 11, 2018: Basic & Clinical Pharmacology & Toxicology
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