keyword
MENU ▼
Read by QxMD icon Read
search

Efflux pumps

keyword
https://www.readbyqxmd.com/read/28210464/evaluation-of-efflux-pumps-gene-expression-in-resistant-pseudomonas-aeruginosa-isolates-in-an-iranian-referral-hospital
#1
Babak Pourakbari, Sahar Yaslianifard, Somaye Yaslianifard, Shima Mahmoudi, Sepideh Keshavarz-Valian, Setareh Mamishi
BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa (PA) is one of the most important causes of nosocomial infections and has an intrinsic resistance to many antibiotics. Among all the resistance-nodulation-division (RND) pumps of P. aeruginosa, MexAB-OprM is the first efflux pump found to target multiple classes of antibiotics. This study was aimed to evaluate the expression level of genes expressing MexAB-OprM in clinical isolates of P. aeruginosa. MATERIALS AND METHODS: In this study, 45 P...
August 2016: Iranian Journal of Microbiology
https://www.readbyqxmd.com/read/28205290/development-and-qualification-of-an-lc-ms-ms-method-for-investigating-the-biological-implications-of-micelle-entrapped-paclitaxel-in-cell-culture-and-rats
#2
Amal Kaddoumi, Kanwaldeep K Gill, Khaled Elfakhri, Sami Nazzal
Paclitaxel is a front-line antineoplastic drug used in chemotherapeutic modalities for treatment of various types of malignancies. However, its efficacy is limited by dose related toxicities. In this study, we have explored two important biological aspects of entrapping paclitaxel in PEG2000 -DSPE micelles. First, we evaluated the impact of this micellar delivery system on P-glycoprotein (P-gp)-paclitaxel interaction, and we investigated differences in plasma pharmacokinetics of free and micelle entrapped paclitaxel...
February 15, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28202577/nimesulide-and-4-hydroxynimesulide-as-bile-acid-transporters-inhibitors-are-contributory-factors-for-drug-induced-cholestasis
#3
Lei Zhou, Xiaoyan Pang, Jingfang Jiang, Dafang Zhong, Xiaoyan Chen
Nimesulide (NIM) is a classic nonsteroidal anti-inflammatory drug. However, some patients treated with NIM suffered from cholestatic liver injury. For this reason, we investigated the potential mechanism underlying NIM-induced cholestasis by using in vivo and in vitro models. Oral administration of 100 mg/kg/day NIM to Wistar rats for 5 days increased the levels of plasma total bile acids, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase by 1.49-, 1.31-, 1.60-, and 1.29-fold, respectively...
February 15, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28193669/overexpression-of-smedef-efflux-pump-decreases-aminoglycoside-resistance-in-stenotrophomonas-maltophilia
#4
Yi-Wei Huang, Cheng-Wen Lin, Hsiao-Chen Ning, Yi-Tsung Lin, Yi-Chih Chang, Tsuey-Ching Yang
The SmeDEF pump of Stenotrophomonas maltophilia is negatively regulated by SmeT. Strains KJΔT (smeT deletion mutant) and KJT-D(m) (mutant with defective SmeT-binding site) showed increased resistance to chloramphenicol/nalidixic acid/macrolides and susceptibility to aminoglycoside. Overexpression of the SmeDEF pump, in either KJΔT or KJT-D(m), downregulated smeYZ expression, which is responsible for the reduced aminoglycoside resistance. Furthermore, the SmeRySy two-component regulatory system was downregulated in response to SmeDFE overexpression, supporting its involvement in the regulatory circuit...
February 13, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28193667/whole-genome-sequencing-of-a-large-panel-of-contemporary-neisseria-gonorrhoeae-clinical-isolates-indicates-that-a-wild-type-mtra-gene-is-common-implications-for-inducible-antimicrobial-resistance
#5
Eshaw Vidyaprakash, A Jeanine Abrams, William M Shafer, David L Trees
Previous studies (1) have shown that the expression of the mtrCDE efflux pump operon is inducible at the transcriptional level in gonococci during incubation in sub-lethal concentrations of the nonionic detergent Triton X-100, which along with antibiotics, bile salts, progesterone and antimicrobial peptides, is a substrate of the MtrCDE efflux pump (2).….
February 13, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28191714/solid-state-nmr-and-epr-spectroscopy-of-mn-2-substituted-atp-fueled-protein-engines
#6
Thomas Wiegand, Denis Lacabanne, Katharina Keller, Riccardo Cadalbert, Lauriane Lecoq, Maxim Yulikov, Laurent Terradot, Gunnar Jeschke, Beat H Meier, Anja Böckmann
Paramagnetic metal ions deliver structural information both in EPR and solid-state NMR experiments, offering a profitable synergetic approach to study bio-macromolecules. We demonstrate the spectral consequences of Mg(2+) / Mn(2+) substitution and the resulting information contents for two different ATP:Mg(2+) -fueled protein engines, a DnaB helicase from Helicobacter pylori active in the bacterial replisome, and the ABC transporter BmrA, a bacterial efflux pump. We show that, while EPR spectra report on metal binding and provide information on the geometry of the metal centers in the proteins, paramagnetic relaxation enhancements identified in the NMR spectra can be used to localize residues at the binding site...
February 13, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28176270/polymers-in-the-co-delivery-of-sirna-and-anticancer-drugs-for-the-treatment-of-drug-resistant-cancers
#7
REVIEW
Haotian Sun, Iven Yarovoy, Meghan Capeling, Chong Cheng
Recently, co-delivery of siRNA and anticancer drugs has drawn much attention in the treatment of drug-resistant cancers. Drug resistance is exhibited by cancer cells, which limits the efficacy of chemotherapy. When siRNA and anticancer drugs are delivered into cancer cells simultaneously, the siRNA is expected to silence the genes related to drug resistance, decreasing the drug efflux pumps and activating the cell's apoptosis pathways. In a timeframe following the release of siRNA, the accumulation of the co-delivered anti-cancer drug inside of the cancer cells will increase, resulting in promoted chemotherapeutic effects...
April 2017: Topics in Current Chemistry (Journal)
https://www.readbyqxmd.com/read/28173641/effects-of-adamantyl-derivatives-on-pharmacokinetic-behavior-of-paclitaxel-in-rats
#8
Kyung Mi Kim, Kyeong Lee, Kyusic Jang, Yae Seul Moon, Hwa Jeong Lee, Sandy Jeong Rhie
Paclitaxel (PTX) is one of the most frequently used anticancer agent for treating refractory ovarian cancer, metastatic breast cancer and non-small cell lung cancer. However, its oral administration is impeded by very low bioavailability (<5%) due to the P-glycopprotein (P-gp) efflux pump effect. This study investigated in vitro and in vivo P-gp inhibitory effects of adamantyl derivatives AC-603 and AC-786 in rats. Two adamantyl derivatives tested in this study increased the cytotoxicity of daunomycin (DNM) in P-gp overexpressed cell line by inhibiting P-gp efflux function...
February 6, 2017: Biomolecules & Therapeutics
https://www.readbyqxmd.com/read/28169223/insights-into-the-ion-coupling-mechanism-in-the-mate-transporter-norm-vc
#9
Alexander Krah, Ulrich Zachariae
Bacteria have developed a variety of different mechanisms to defend themselves from compounds that are toxic to them, such as antibiotics. One of these defence mechanisms is the expulsion of drugs or other noxious compounds by multidrug efflux pumps. Multidrug and toxic compound extrusion (MATE) transporters are efflux pumps that extrude metabolic waste and a variety of antibiotics out of the cell, using an ion gradient as energy source. They function via an alternative-access mechanism. When ions bind in the outward facing conformation, a large conformational change to the inward facing conformation is induced, from which the ion is released and the extruded chemical compound is bound...
February 7, 2017: Physical Biology
https://www.readbyqxmd.com/read/28167562/tenofovir-disoproxil-fumarate-tdf-a-new-substrate-of-atp-binding-cassette-subfamily-c11-abcc11-mrp8
#10
Wisith Tun-Yhong, Chatchai Chinpaisal, Perayot Pamonsinlapatham, Sindchai Kaewkitichai
Tenofovir disoproxil fumarate (TDF), a nucleotide reverse transcriptase inhibitor, after conversion to TFV, is mainly eliminated by glomerular filtration and active tubular secretion. The major adverse effect of tenofovir is nephrotoxicity, however, the exact mechanism remains poorly understood. In this study, ABCC11 (MRP8) transporter, a member of ATP-binding cassette subfamily C11, which is abundant in proximal tubular cells, was demonstrated to efflux tenofovir. Real-time polymerase chain reaction (rt-PCR) and indirect immunofluorescence assays were used to determine MRP8 overexpression in a continuous cell line...
February 6, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28162983/activity-of-moxifloxacin-and-linezolid-against-mycobacterium-tuberculosis-in-combination-with-potentiator-drugs-verapamil-timcodar-colistin-and-sq109
#11
Gerjo J de Knegt, Aart van der Meijden, Corné P de Vogel, Rob E Aarnoutse, Jurriaan E M de Steenwinkel
Current treatment for tuberculosis (TB) is complicated by the emergence of multidrug resistant TB (MDR-TB). As a result, there is an urgent need for new powerful anti-TB regimens and novel strategies. In this study, we aimed to potentiate a moxifloxacin + linezolid backbone as treatment for MDR-TB with the efflux pump inhibitors verapamil and timcodar as well as with drugs that act on mycobacterial cell wall stability such as colistin and SQ109. Using a time-kill kinetics assay, the activities of moxifloxacin, linezolid, verapamil, timcodar, colistin and SQ109 as single drugs against Mycobacterium tuberculosis were evaluated...
February 2, 2017: International Journal of Antimicrobial Agents
https://www.readbyqxmd.com/read/28161596/polygoni-multiflori-radix-derived-anthraquinones-alter-bile-acid-disposition-in-sandwich-cultured-rat-hepatocytes
#12
Li Kang, Luqin Si, Jing Rao, Dan Li, Ya Wu, Sanlan Wu, Minghui Wu, Sijie He, Wenwen Zhu, Yang Wu, Jiaqiang Xu, Gao Li, Jiangeng Huang
Hepatic adverse reaction associated with Polygoni Multiflori Radix (PMR) has been frequently reported in recent years. Highly-enriched anthraquinones (AQs) in PMR, such as emodin, chrysophanol and physcion, have been found to be hepatotoxic. In the present study, sandwich-cultured rat hepatocytes (SCRHs) were employed to investigate the effect of individual and combined AQs on the disposition of endogenous bile acids (BAs) and exogenous probe substrates including deuterium-labeled taurocholate (d5-TCA), glycochenodeoxycholic acid (d4-GCDCA) and 5 (and 6)-carboxy-2,7'dichlorofluorescein (CDF)...
February 1, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28160861/antibacterial-activity-of-epigallocatechin-3-gallate-egcg-and-its-synergism-with-%C3%AE-lactam-antibiotics-sensitizing-carbapenem-associated-multidrug-resistant-clinical-isolates-of-acinetobacter-baumannii
#13
Spencer Lee, Ghaida Saleh Al Razqan, Dong H Kwon
BACKGROUND: Infections caused by Acinetobacter baumannii were responsive to conventional antibiotic therapy. However, recently, carbapenem-associated multidrug resistant isolates have been reported worldwide and present a major therapeutic challenge. Epigallocatechin-3-Gallate (EGCG) extracted from green tea exhibits antibacterial activity. PURPOSE: We evaluated the antibacterial activity of EGCG and possible synergism with antibiotics in carbapenem-associated multidrug resistant A...
January 15, 2017: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
https://www.readbyqxmd.com/read/28159755/role-of-ectopic-gene-conversion-in-the-evolution-of-a-candida-krusei-pleiotropic-drug-resistance-transporter-family
#14
Erwin Lamping, Jing-Yi Zhu, Masakazu Niimi, Richard David Cannon
Gene duplications enable the evolution of novel gene function, but strong positive selection is required to preserve advantageous mutations in a population. This is because frequent ectopic gene conversions (EGCs) between highly similar, tandem-duplicated, sequences, can rapidly remove fate determining mutations by replacing them with the neighbouring parent gene sequences. Unfortunately, the high sequence similarities between tandem-duplicated genes severely hamper empirical studies of this important evolutionary process because deciphering their correct sequences is challenging...
February 3, 2017: Genetics
https://www.readbyqxmd.com/read/28157581/survival-of-listeria-monocytogenes-with-different-antibiotic-resistance-patterns-to-food-associated-stresses
#15
Norton Komora, Carolina Bruschi, Rui Magalhães, Vânia Ferreira, Paula Teixeira
The ongoing rise of antibiotic resistant microbial pathogens has become one of the major public health threats worldwide. Despite all the effort and actions taken so far, a proliferation of antibiotic resistant (AR) and multi-antibiotic resistant (MAR) strains is still observed, including in foodborne pathogens. This trend has been also noted recently for isolates of Listeria monocytogenes, a species that, although remaining largely sensitive to clinically relevant antimicrobials, has been reported to develop increased tolerance to antibiotics, particularly in isolates recovered from the food-chain...
January 24, 2017: International Journal of Food Microbiology
https://www.readbyqxmd.com/read/28155846/rationalizing-the-permeation-of-polar-antibiotics-into-gram-negative-bacteria
#16
Mariano Andrea Scorciapino, Silvia Acosta-Gutierrez, Dehbia Benkerrou, Tommaso D'Agostino, Giuliano Malloci, Susruta Samanta, Igor Bodrenko, Matteo Ceccarelli
The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds...
March 22, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28154323/exploration-of-molecular-targets-in-the-development-of-new-therapeutics-aimed-at-overcoming-multidrug-resistance
#17
Shozo Nishida, Masanobu Tsubaki
 Multidrug resistance (MDR) in cancer is a major problem in clinical settings: MDR correlates with a patient's poor prognosis and decreased quality of life. Recently, MDR was found to be involved in various signal pathways, so the inhibition of signal molecules by molecular targeting drugs may help overcome MDR. In addition, the acquisition of MDR is shown to be associated with the overexpression of drug efflux pumps such as P-glycoprotein (MDR1), which in turn affects the regulation of the expression of cell survival factors, B-cell leukemia protein 2 (Bcl-2) family proteins, etc...
2017: Yakugaku Zasshi: Journal of the Pharmaceutical Society of Japan
https://www.readbyqxmd.com/read/28153721/mir-138-indirectly-regulates-the-mdr1-promoter-by-nf-%C3%AE%C2%BAb-p65-silencing
#18
J L Requenez-Contreras, E S López-Castillejos, R Hernández-Flores, M A Moreno-Eutimio, J T Granados-Riveron, G U Martinez-Ruiz, G Aquino-Jarquin
MicroRNAs (miRNAs) are known to mediate post-transcriptional gene silencing in the cytoplasm and recent evidence indicates that may also possess nuclear roles in regulating gene expression. A recent study showed that miR-138 is involved in the multidrug resistance of leukemia cells through down-regulation of the drug efflux pump P-glycoprotein (P-gp), the protein encoded by the human multidrug-resistant ABCB1/MDR1 gene. However, the transcriptional regulatory mechanisms responsible remain to be elucidated. To deepen the description of the mechanism of transcriptional gene silencing on the MDR1 promoter, we initially performed a bioinformatics search for potential miR-138 binding sites in the MDR1 gene promoter sequence...
January 30, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28152547/neratinib-resistance-and-cross-resistance-to-other-her2-targeted-drugs-due-to-increased-activity-of-metabolism-enzyme-cytochrome-p4503a4
#19
Susan Breslin, Michelle C Lowry, Lorraine O'Driscoll
BACKGROUND: Neratinib is in Phase 3 clinical trials but, unfortunately, the development of resistance is inevitable. Here, we investigated the effects of acquired neratinib resistance on cellular phenotype and the potential mechanism of this resistance. METHODS: Neratinib-resistant variants of HER2-positive breast cancer cells were developed and their cross-resistance investigated using cytotoxicity assays. Similarly, sensitivity of trastuzumab-resistant and lapatinib-resistant cells to neratinib was assessed...
February 2, 2017: British Journal of Cancer
https://www.readbyqxmd.com/read/28146280/assessment-of-bile-salt-export-pump-bsep-inhibition-in-membrane-vesicles-using-radioactive-and-lc-ms-based-detection-methods
#20
Lisa D Marroquin, Paul D Bonin, Julie Keefer, Thomas Schroeter
The bile salt export pump (BSEP, ABCB11) belongs to the ATP-binding-cassette superfamily of transporters and is predominately found in the liver. BSEP is an efflux transporter that plays a critical role in the secretion of bile salts into the bile. Inhibition of BSEP function by drugs can result in the buildup of bile salts in the liver and eventually leads to cholestasis and drug-induced liver injury (DILI). DILI is a major cause of withdrawal of drugs from the pharmaceutical market and accounts for >50% of acute liver failures...
February 1, 2017: Current Protocols in Toxicology
keyword
keyword
34167
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"