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  1 / 4483 MEDLINE  
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PMID:28452155
Autor:Ikeno T; Nagano T; Hanaoka K
Endereço:Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Título:Silicon-substituted Xanthene Dyes and Their Unique Photophysical Properties for Fluorescent Probes.
Fonte:Chem Asian J; 12(13):1435-1446, 2017 Jul 04.
ISSN:1861-471X
País de publicação:Germany
Idioma:eng
Resumo:Silicon-substituted xanthene dyes, with Si in place of the O atom at the xanthene 10-position, are practically useful as far-red to near-infrared fluorophores. Many fluorescent probes based on them have recently been reported. These fluorophores retain the advantages of typical xanthene dyes and also show unique properties suitable for applications such as multi-color and super-resolution imaging.
Tipo de publicação: JOURNAL ARTICLE; REVIEW
Nome de substância:0 (Fluorescent Dyes); 0 (Xanthenes); Z4152N8IUI (Silicon)


  2 / 4483 MEDLINE  
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PMID:28470516
Autor:Ivanov DP; Grabowska AM; Garnett MC
Endereço:Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK. delyan.ivanov@nottingham.ac.uk.
Título:High-Throughput Spheroid Screens Using Volume, Resazurin Reduction, and Acid Phosphatase Activity.
Fonte:Methods Mol Biol; 1601:43-59, 2017.
ISSN:1940-6029
País de publicação:United States
Idioma:eng
Resumo:Mainstream adoption of physiologically relevant three-dimensional models has been slow in the last 50 years due to long, manual protocols with poor reproducibility, high price, and closed commercial platforms. This chapter describes high-throughput, low-cost, open methods for spheroid viability assessment which use readily available reagents and open-source software to analyze spheroid volume, metabolism, and enzymatic activity. We provide two ImageJ macros for automated spheroid size determination-for both single images and images in stacks. We also share an Excel template spreadsheet allowing users to rapidly process spheroid size data, analyze plate uniformity (such as edge effects and systematic seeding errors), detect outliers, and calculate dose-response. The methods would be useful to researchers in preclinical and translational research planning to move away from simplistic monolayer studies and explore 3D spheroid screens for drug safety and efficacy without substantial investment in money or time.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Indicators and Reagents); 0 (Oxazines); 0 (Xanthenes); 1FN9YD6968 (resazurin); EC 3.1.3.2 (Acid Phosphatase)


  3 / 4483 MEDLINE  
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PMID:28470513
Autor:Präbst K; Engelhardt H; Ringgeler S; Hübner H
Endereço:Institute of Bioprocess Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052, Erlangen, Germany. konstantin.praebst@fau.de.
Título:Basic Colorimetric Proliferation Assays: MTT, WST, and Resazurin.
Fonte:Methods Mol Biol; 1601:1-17, 2017.
ISSN:1940-6029
País de publicação:United States
Idioma:eng
Resumo:This chapter describes selected assays for the evaluation of cellular viability and proliferation of cell cultures. The underlying principle of these assays is the measurement of a biochemical marker to evaluate the cell's metabolic activity. The formation of the omnipresent reducing agents NADH and NADPH is used as a marker for metabolic activity in the following assays. Using NADH and NADPH as electron sources, specific dyes are biochemically reduced which results in a color change that can be determined with basic photometrical methods. The assays selected for this chapter include MTT, WST, and resazurin. They are applicable for adherent or suspended cell lines, easy to perform, and comparably economical. Detailed protocols and notes for easier handling and avoiding pitfalls are enclosed to each assay.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium monosodium salt); 0 (Indicators and Reagents); 0 (Oxazines); 0 (Tetrazolium Salts); 0 (Thiazoles); 0 (Xanthenes); 0U46U6E8UK (NAD); 1FN9YD6968 (resazurin); 53-59-8 (NADP); EUY85H477I (thiazolyl blue)


  4 / 4483 MEDLINE  
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PMID:27776597
Autor:Pina RZ; Caleffi-Ferracioli KR; Campanerut-Sá PA; Ghiraldi-Lopez LD; Pavan FR; Siqueira VL; Scodro RB; Cardoso RF
Endereço:Post-Graduate Programme in Health Sciences, State University of Maringá, Maringá, Brazil.
Título:Pyrazinamide susceptibility testing in Mycobacterium tuberculosis using the fast resazurin microtiter assay plate.
Fonte:Int J Tuberc Lung Dis; 20(11):1535-1538, 2016 Nov.
ISSN:1815-7920
País de publicação:France
Idioma:eng
Resumo:SETTING: Department of Clinical Analysis and Biomedicine, State University of Maringa, Maringa, PR, Brazil. OBJECTIVE: To evaluate the performance of the resazurin microtiter assay (REMA) plate at pH 5.5 in detecting Mycobacterium tuberculosis susceptibility to pyrazinamide (PZA). DESIGN: The minimal inhibitory concentration (MIC) of PZA in M. tuberculosis H Rv and M. bovis AN5 reference strains and in 34 clinical M. tuberculosis isolates (26 PZA-susceptible and eight PZA-resistant) was determined using REMA at pH 5.5 and compared to REMA at pH 6.0. RESULTS: REMA at pH 5.5 was helpful in discriminating PZA-susceptible from resistant M. tuberculosis isolates when â©¿50 µg/ml PZA was considered as the cut-off for PZA susceptibility. Furthermore, it provided results in 8 days. However, two PZA-resistant isolates failed to grow at pH 5.5. CONCLUSION: As the REMA method is rapid, inexpensive, easy to perform and read, it would be of great usefulness in low-income countries for detecting PZA-resistant M. tuberculosis. REMA at pH 5.6-5.9 should be evaluated on an extended panel of clinical M. tuberculosis isolates with a greater range of MIC values in different laboratories for a better understanding of its utility in differentiating PZA-resistant from PZA-susceptible isolates.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antitubercular Agents); 0 (Oxazines); 0 (Xanthenes); 1FN9YD6968 (resazurin); 2KNI5N06TI (Pyrazinamide)


  5 / 4483 MEDLINE  
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PMID:29186951
Autor:Vismeh R; Haddad D; Moore J; Nielson C; Bals B; Campbell T; Julian A; Teymouri F; Jones AD; Bringi V
Endereço:Michigan Biotechnology Institute , Lansing, Michigan 48910, United States.
Título:Exposure Assessment of Acetamide in Milk, Beef, and Coffee Using Xanthydrol Derivatization and Gas Chromatography/Mass Spectrometry.
Fonte:J Agric Food Chem; 66(1):298-305, 2018 Jan 10.
ISSN:1520-5118
País de publicação:United States
Idioma:eng
Resumo:Acetamide has been classified as a possible human carcinogen, but uncertainties exist about its levels in foods. This report presents evidence that thermal decomposition of N-acetylated sugars and amino acids in heated gas chromatograph injectors contributes to artifactual acetamide in milk and beef. An alternative gas chromatography/mass spectrometry protocol based on derivatization of acetamide with 9-xanthydrol was optimized and shown to be free of artifactual acetamide formation. The protocol was validated using a surrogate analyte approach based on d -acetamide and applied to analyze 23 pasteurized whole milk, 44 raw sirloin beef, and raw milk samples from 14 different cows, and yielded levels about 10-fold lower than those obtained by direct injection without derivatization. The xanthydrol derivatization procedure detected acetamide in every food sample tested at 390 ± 60 ppb in milk, 400 ± 80 ppb in beef, and 39 000 ± 9000 ppb in roasted coffee beans.
Tipo de publicação: EVALUATION STUDIES; JOURNAL ARTICLE
Nome de substância:0 (Acetamides); 0 (Coffee); 0 (Xanthenes); 7131M69IKF (xanthydrol); 8XOE1JSO29 (acetamide)


  6 / 4483 MEDLINE  
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PMID:29235815
Autor:Tarasenko AS
Título:Effect of nitric oxide donor SNAP on GABA release from rat brain nerve terminals.
Fonte:Ukr Biochem J; 88(5):82-9, 2016 Sep-Oct.
ISSN:2409-4943
País de publicação:Ukraine
Idioma:eng
Resumo:In this work we investigated the effect of nanomolar concentrations of nitric oxide on the release of gamma-aminobutyric acid (GABA) from rat brain nerve terminals using a radioisotope method with [3H]GABA and a spectrofluorimetric method with Ca2+-sensitive probe Fluo-4 AM. It was shown that in the presen­ce of dithiothreitol (DTT), nitric oxide donor SNAP at concentration, in which it produces NO in the nanomolar range, caused Ca2+-independent [3H]GABA release from nerve terminals. The applications of 4-aminopyridine (4-AP) and nipecotic acid (NA), as the inducers of GABA release from vesicular and cytoplasmic pools, showed that the maximum of SNAP/+DTT-induced [3H]GABA release was registered at 10th min of incubation and coincided in time with significant increase (almost double) in NA-induced [3H]GABA release. At this time point, 4-AP-induced release of [3H]GABA was drastically reduced. At the 15th min of incubation of nerve terminals with SNAP/+DTT, the opposite picture was observed: the decrease in NA- and increase in 4-AP-induced [3H]GABA release. Thus, nitric oxide in the form of S-nitrosothiols at nanomolar concentrations causes Ca2+-independent GABA leakage from synaptic vesicles into cytosol with subsequent release from nerve terminals. The reuptake of the neurotransmitter and its re-accumulation in synaptic vesicles occur later.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Aniline Compounds); 0 (Fluo 4); 0 (Fluorescent Dyes); 0 (Nipecotic Acids); 0 (Xanthenes); 1U1QTN40SY (nipecotic acid); 31C4KY9ESH (Nitric Oxide); 56-12-2 (gamma-Aminobutyric Acid); 79032-48-7 (S-Nitroso-N-Acetylpenicillamine); BH3B64OKL9 (4-Aminopyridine); SY7Q814VUP (Calcium); T8ID5YZU6Y (Dithiothreitol)


  7 / 4483 MEDLINE  
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PMID:28915422
Autor:Legrand T; Rakotoson MG; Galactéros F; Bartolucci P; Hulin A
Endereço:Laboratoire de Pharmacologie-Toxicologie, Hôpitaux Universitaires Henri Mondor, Assistance Publique des Hôpitaux de Paris, 94000 Créteil, France. Electronic address: tiphaine.legrand@aphp.fr.
Título:Determination of hydroxyurea in human plasma by HPLC-UV using derivatization with xanthydrol.
Fonte:J Chromatogr B Analyt Technol Biomed Life Sci; 1064:85-91, 2017 Oct 01.
ISSN:1873-376X
País de publicação:Netherlands
Idioma:eng
Resumo:A simple and rapid high performance liquid chromatography (HPLC) method using ultraviolet (UV) detection was developed to determine hydroxyurea (HU) concentration in plasma sample after derivatization with xanthydrol. Two hundred microliters samples were spiked with methylurea (MeU) as internal standard and proteins were precipitated by adding methanol. Derivatization of HU and MeU was immediately performed by adding 0.02M xanthydrol and 1.5M HCl in order to obtain xanthyl-derivatives of HU and MeU that can be further separated using HPLC and quantified using UV detection at 240nm. Separation was achieved using a C18 column with a mobile phase composed of 20mM ammonium acetate and acetonitrile in gradient elution mode at a flow rate of 1mL/min. The total analysis time did not exceed 18min. The method was found linear from 5 to 400µM and all validation parameters fulfilled the international requirements. Between- and within-run accuracy error ranged from -4.7% to 3.2% and precision was lower than 12.8%. This simple method requires small volume samples and can be easily implemented in most clinical laboratories to develop pharmacokinetics studies of HU and to promote its therapeutic monitoring.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Xanthenes); 7131M69IKF (xanthydrol); X6Q56QN5QC (Hydroxyurea)


  8 / 4483 MEDLINE  
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PMID:28818206
Autor:Travers JG; Kamal FA; Valiente-Alandi I; Nieman ML; Sargent MA; Lorenz JN; Molkentin JD; Blaxall BC
Endereço:Department of Pediatrics, Division of Molecular Cardiovascular Biology, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
Título:Pharmacological and Activated Fibroblast Targeting of Gßγ-GRK2 After Myocardial Ischemia Attenuates Heart Failure Progression.
Fonte:J Am Coll Cardiol; 70(8):958-971, 2017 Aug 22.
ISSN:1558-3597
País de publicação:United States
Idioma:eng
Resumo:BACKGROUND: Cardiac fibroblasts are a critical cell population responsible for myocardial extracellular matrix homeostasis. Upon injury or pathological stimulation, these cells transform to an activated myofibroblast state and play a fundamental role in myocardial fibrosis and remodeling. Chronic sympathetic overstimulation, a hallmark of heart failure (HF), induces pathological signaling through G protein ßγ (Gßγ) subunits and their interaction with G protein-coupled receptor kinase 2 (GRK2). OBJECTIVES: This study investigated the hypothesis that Gßγ-GRK2 inhibition and/or ablation after myocardial injury would attenuate pathological myofibroblast activation and cardiac remodeling. METHODS: The therapeutic potential of small molecule Gßγ-GRK2 inhibition, alone or in combination with activated fibroblast- or myocyte-specific GRK2 ablation-each initiated after myocardial ischemia-reperfusion (I/R) injury-was investigated to evaluate the possible salutary effects on post-I/R fibroblast activation, pathological remodeling, and cardiac dysfunction. RESULTS: Small molecule Gßγ-GRK2 inhibition initiated 1 week post-injury was cardioprotective in the I/R model of chronic HF, including preservation of cardiac contractility and a reduction in cardiac fibrotic remodeling. Systemic small molecule Gßγ-GRK2 inhibition initiated 1 week post-I/R in cardiomyocyte-restricted GRK2 ablated mice (also post-I/R) still demonstrated significant cardioprotection, which suggested a potential protective role beyond the cardiomyocyte. Inducible ablation of GRK2 in activated fibroblasts (i.e., myofibroblasts) post-I/R injury demonstrated significant functional cardioprotection with reduced myofibroblast transformation and fibrosis. Systemic small molecule Gßγ-GRK2 inhibition initiated 1 week post-I/R provided little to no further protection in mice with ablation of GRK2 in activated fibroblasts alone. Finally, Gßγ-GRK2 inhibition significantly attenuated activation characteristics of failing human cardiac fibroblasts isolated from end-stage HF patients. CONCLUSIONS: These findings suggested consideration of a paradigm shift in the understanding of the therapeutic role of Gßγ-GRK2 inhibition in treating HF and the potential therapeutic role for Gßγ-GRK2 inhibition in limiting pathological myofibroblast activation, interstitial fibrosis, and HF progression.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Xanthenes); 8L0084U2QR (gallein); EC 2.7.11.15 (ADRBK1 protein, human); EC 2.7.11.16 (G-Protein-Coupled Receptor Kinase 2)


  9 / 4483 MEDLINE  
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PMID:28793293
Autor:Al Mamun Bhuyan A; Cao H; Lang F
Endereço:Department of Internal Medicine III, Tuebingen, Germany.
Título:Triggering of Eryptosis, the Suicidal Erythrocyte Death by Mammalian Target of Rapamycin (mTOR) inhibitor Temsirolimus.
Fonte:Cell Physiol Biochem; 42(4):1575-1591, 2017.
ISSN:1421-9778
País de publicação:Switzerland
Idioma:eng
Resumo:BACKGROUND/AIMS: The mammalian target of rapamycin (mTOR) inhibitor temsirolimus is utilized for the treatment of malignancy. Temsirolimus is at least in part effective by triggering suicidal tumor cell death. The most common side effect of temsirolimus treatment is anemia. At least in theory, the anemia following temsirolimus treatment could result from stimulation of eryptosis, the suicidal erythrocyte death. Hallmarks of eryptosis include cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Signaling involved in the orchestration of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i), oxidative stress, ceramide, as well as activation of staurosporine and chelerythrine sensitive protein kinase C, SB203580 sensitive p38 kinase, D4476 sensitive casein kinase 1, and zVAD sensitive caspases. The purpose of the present study was to test whether temsirolimus influences eryptosis and, if so, to shed light on the signaling involved. METHODS: Flow cytometry was employed to estimate cell volume from forward scatter, phosphatidylserine exposure at the cell surface from annexin-V-binding, [Ca2+]i from Fluo3-fluorescence, reactive oxygen species (ROS) abundance from DCFDA dependent fluorescence, and ceramide abundance utilizing specific antibodies. Hemolysis was determined from hemoglobin concentration in the supernatant. RESULTS: A 48 hours exposure of human erythrocytes to temsirolimus (5 - 20 µg/ml) significantly decreased forward scatter and significantly increased the percentage of annexin-V-binding cells. Temsirolimus significantly increased Fluo3-fluorescence, DCFDA fluorescence and ceramide abundance at the erythrocyte surface. The effect of temsirolimus on annexin-V-binding was significantly blunted but not abolished by removal of extracellular Ca2+ and by addition of staurosporine (1 µM) or chelerythrine (10 µM) but not significantly modified by addition of SB203580 (2 µM), D4476 (10 µM), or zVAD (10 µM). Chelerythrine (10 µM) further significantly blunted the effect of temsirolimus on DCFDA fluorescence but not ceramide formation. Removal of extracellular Ca2+ had no effect on temsirolimus induced ROS formation or ceramide abundance. CONCLUSIONS: Temsirolimus triggers eryptosis with cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part due to Ca2+ entry, oxidative stress, ceramide and activation of staurosporine/Chelerythrine sensitive kinase(s).
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (4-(4-(2,3-dihydrobenzo(1,4)dioxin-6-yl)-5-pyridin-2-yl-1H-imidazol-2-yl)benzamide); 0 (Aniline Compounds); 0 (Annexin A5); 0 (Antineoplastic Agents); 0 (Benzamides); 0 (Benzophenanthridines); 0 (Ceramides); 0 (Fluoresceins); 0 (Imidazoles); 0 (Oligopeptides); 0 (Phosphatidylserines); 0 (Protein Kinase Inhibitors); 0 (Pyridines); 0 (Reactive Oxygen Species); 0 (Xanthenes); 0 (benzyloxycarbonyl-valyl-alanyl-aspartic acid); 2044-85-1 (diacetyldichlorofluorescein); 23D4W0B50Y (Fluo-3); 624KN6GM2T (temsirolimus); E3B045W6X0 (chelerythrine); EC 2.7.1.1 (MTOR protein, human); EC 2.7.1.1 (TOR Serine-Threonine Kinases); EC 2.7.11.1 (Casein Kinase I); EC 2.7.11.24 (p38 Mitogen-Activated Protein Kinases); EC 3.4.22.- (Caspases); H88EPA0A3N (Staurosporine); OU13V1EYWQ (SB 203580); SY7Q814VUP (Calcium); W36ZG6FT64 (Sirolimus)


  10 / 4483 MEDLINE  
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PMID:28781167
Autor:Koren D; Grove JCR; Wei W
Endereço:Department of Neurobiology, The University of Chicago, Chicago, IL 60637, USA; Interdisciplinary Scientist Training Program, The University of Chicago, Chicago, IL 60637, USA.
Título:Cross-compartmental Modulation of Dendritic Signals for Retinal Direction Selectivity.
Fonte:Neuron; 95(4):914-927.e4, 2017 Aug 16.
ISSN:1097-4199
País de publicação:United States
Idioma:eng
Resumo:Compartmentalized signaling in dendritic subdomains is critical for the function of many central neurons. In the retina, individual dendritic sectors of a starburst amacrine cell (SAC) are preferentially activated by different directions of linear motion, indicating limited signal propagation between the sectors. However, the mechanism that regulates this propagation is poorly understood. Here, we find that metabotropic glutamate receptor 2 (mGluR2) signaling, which acts on voltage-gated calcium channels in SACs, selectively restricts cross-sector signal propagation in SACs, but does not affect local dendritic computation within individual sectors. mGluR2 signaling ensures sufficient electrotonic isolation of dendritic sectors to prevent their depolarization during non-preferred motion, yet enables controlled multicompartmental signal integration that enhances responses to preferred motion. Furthermore, mGluR2-mediated dendritic compartmentalization in SACs is important for the functional output of direction-selective ganglion cells (DSGCs). Therefore, our results directly link modulation of dendritic compartmentalization to circuit-level encoding of motion direction in the retina.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Amino Acids); 0 (Calcium Channel Blockers); 0 (Excitatory Amino Acid Antagonists); 0 (LY 341495); 0 (Receptors, AMPA); 0 (Xanthenes); 0 (glutamate receptor ionotropic, AMPA 2); 92078-76-7 (omega-Conotoxin GVIA); J6K4F9V3BA (Cadmium Chloride)



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