Base de dados : MEDLINE
Pesquisa : D02.078.370.570 [Categoria DeCS]
Referências encontradas : 280 [refinar]
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[PMID]:28241998
[Au] Autor:Bosco AM; Almeida BF; Pereira PP; Dos Santos DB; Neto ÁJ; Ferreira WL; Ciarlini PC
[Ad] Endereço:Department of Clinical Practice, Surgery and Animal Reproduction, Araçatuba College of Veterinary Medicine, São Paulo State University (UNESP), Araçatuba, SP, Brazil. Electronic address: anebosco@hotmail.com.
[Ti] Título:The uremic toxin methylguanidine increases the oxidative metabolism and accelerates the apoptosis of canine neutrophils.
[So] Source:Vet Immunol Immunopathol;185:14-19, 2017 Mar.
[Is] ISSN:1873-2534
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:We investigated the hypothesis that the increased concentration of plasma methylguanidine (MG) increases oxidative metabolism and accelerates apoptosis of neutrophils from dogs with chronic kidney disease (CKD). To achieve this, the levels of MG were quantified in healthy (n=16) and uremic dogs with CKD stage 4 of according to the guidelines of the International Renal Interest Society (IRIS, 2015) (n=16) using high performance liquid chromatography (HPLC). To evaluate the isolated effect of MG on neutrophil oxidative metabolism and apoptosis, neutrophils isolated from 12 healthy dogs were incubated with the highest concentration of plasma MG (0.005g/L) observed in dogs with CKD. Neutrophil oxidative metabolism was assessed by flow cytometry, using the probes hydroethidine for superoxide production and 2',7'-dichlorofluorescein diacetate for hydrogen peroxide production, with or without phorbol myristate acetate (PMA) stimulus. Neutrophil apoptosis and viability were also evaluated in flow cytometer using the Annexin V-PE system, with or without the apoptosis-inducing effect of camptothecin. Uremic dogs presented higher concentrations of MG (p<0.0001), increased oxidative stress and primed neutrophils with higher apoptosis rate. The neutrophil abnormalities observed in vivo were also reproduced in vitro, using cells isolated from healthy dogs and incubated with MG. We obtained strong evidence that in dogs with CKD, increased MG levels contributed to oxidative stress and potentially compromised the non-specific immune response by altering the oxidative metabolism and viability of canine neutrophils.
[Mh] Termos MeSH primário: Apoptose
Metilguanidina/sangue
Neutrófilos
Insuficiência Renal Crônica/veterinária
[Mh] Termos MeSH secundário: Animais
Cães
Feminino
Masculino
Estresse Oxidativo
Insuficiência Renal Crônica/sangue
Insuficiência Renal Crônica/imunologia
Uremia/imunologia
Uremia/veterinária
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
5L0H5Q9VAG (Methylguanidine)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170623
[Lr] Data última revisão:
170623
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170301
[St] Status:MEDLINE


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[PMID]:27383162
[Au] Autor:Skliarova EI; Popova TN; Shulgin KK
[Ad] Endereço:Voronezh State University, Voronezh, Russia. katttilda@mail.ru.
[Ti] Título:Effects of N-[Imino(1-Piperidinyl)Methyl] Guanidine on the Intensity of Free Radical Processes, Aconitase Activity, and Citrate Level in the Tissues of Rats with Experimental Type 2 Diabetes Mellitus.
[So] Source:Bull Exp Biol Med;161(2):261-5, 2016 Jun.
[Is] ISSN:1573-8221
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Effects of a synthetic biguanide derivative N-[imino(1-piperidinyl)methyl] guanidine (NIPMG) on free radical homeostasis, aconitase activity, and citrate concentration were studied in the liver and blood serum of rats with type 2 diabetes mellitus. Analysis of biochemiluminescence parameters showed that administration of this agent (10 mg/kg body weight) to animals with diabetes reduced the intensity of free radical processes in study tissues relative to the increased values in untreated diabetic animals. Under these conditions, aconitase activity, a principal target of ROS effects, and citrate level in the liver and blood serum of rats approached the control levels. The results show that NIPMG can positively regulate free radical homeostasis and reduce the intensity of oxidative stress in type 2 diabetes mellitus, which was accompanied by normalization of the studied parameters.
[Mh] Termos MeSH primário: Aconitato Hidratase/metabolismo
Citratos/metabolismo
Diabetes Mellitus Experimental/tratamento farmacológico
Diabetes Mellitus Tipo 2/tratamento farmacológico
Hipoglicemiantes/farmacologia
Metilguanidina/análogos & derivados
Piperidinas/farmacologia
[Mh] Termos MeSH secundário: Animais
Diabetes Mellitus Experimental/sangue
Diabetes Mellitus Tipo 2/sangue
Avaliação Pré-Clínica de Medicamentos
Fígado/metabolismo
Masculino
Metilguanidina/farmacologia
Ratos
Espécies Reativas de Oxigênio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Citrates); 0 (Hypoglycemic Agents); 0 (N-(imino(1-piperidinyl)methyl)guanidine); 0 (Piperidines); 0 (Reactive Oxygen Species); 5L0H5Q9VAG (Methylguanidine); EC 4.2.1.3 (Aconitate Hydratase)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170207
[Lr] Data última revisão:
170207
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160708
[St] Status:MEDLINE
[do] DOI:10.1007/s10517-016-3391-5


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[PMID]:26860556
[Au] Autor:Zounr RA; Khuhawar MY; Jahangir TM; Alamgir M
[Ad] Endereço:Institute of Advanced Research Studies in Chemical Sciences, University of Sindh.
[Ti] Título:Improved Gas Chromatographic Determination of Guanidino Compounds Using Isovaleroylacetone and Ethyl Chloroformate as Derivatizing Reagents.
[So] Source:Anal Sci;32(2):141-6, 2016.
[Is] ISSN:1348-2246
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:An improved GC method in terms of sensitivity and decrease in the analysis time has been developed for the analysis of eight guanidino compounds: guanidine (G), methylguanidine (MG), creatinine (CTN), guanidinoacetic acid (GAA), guanidinobutyric acid (GBA), guanidinopropionic acid (GPA), argenine (Arg), and guanidinosuccinic acid (GSA), using isovaleroylacetone (IVA) and ethyl chloroformate (ECF) as derivatizing reagents. The separation was obtained from column HP-5 (30 m × 0.32 mm i.d.) with film thickness of 0.25 µm within 11 min. The linear calibrations were obtained with 0.5 to 50 µg/mL with coefficient of determination (R(2)) within 0.9969 - 0.9998. Limits of detections (LODs) were within 5 - 140 ng/mL. The derivatization, separation and determination was repeatable (n = 6) with relative standard deviation (RSD) within 1.2 - 3.1%. The guanidino compounds were determined in deproteinized serum of healthy volunteers and uremic patients within below LOD to 8.8 µg/mL and below LOD to 43.99 µg/mL with RSD within 1.4 - 3.6%. The recovery of guanidino compounds calculated by standard addition from serum was within 96.1 - 98.9%, with RSD 1.4 - 3.6%.
[Mh] Termos MeSH primário: Arginina/análise
Ácido Butírico/análise
Cromatografia Gasosa/métodos
Creatinina/análise
Guanidina/análise
Uremia/sangue
[Mh] Termos MeSH secundário: Acetona/química
Ácidos Bóricos/química
Butiratos/análise
Calibragem
Ésteres do Ácido Fórmico/química
Glicina/análogos & derivados
Glicina/análise
Guanidinas/análise
Voluntários Saudáveis
Seres Humanos
Concentração de Íons de Hidrogênio
Cetonas/química
Limite de Detecção
Metilguanidina/análise
Propionatos/análise
Valores de Referência
Reprodutibilidade dos Testes
Succinatos/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Boric Acids); 0 (Butyrates); 0 (Formic Acid Esters); 0 (Guanidines); 0 (Ketones); 0 (Propionates); 0 (Succinates); 09601EZP9R (ethyl chloroformate); 107-92-6 (Butyric Acid); 1364PS73AF (Acetone); 5L0H5Q9VAG (Methylguanidine); 6133-30-8 (guanidinosuccinic acid); 94ZLA3W45F (Arginine); AYI8EX34EU (Creatinine); GO52O1A04E (glycocyamine); JU58VJ6Y3B (Guanidine); R57ZHV85D4 (boric acid); TE7660XO1C (Glycine); UL1984YRKA (guanidinopropionic acid)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:170103
[Lr] Data última revisão:
170103
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160211
[St] Status:MEDLINE
[do] DOI:10.2116/analsci.32.141


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[PMID]:26588360
[Au] Autor:Naumiec GR; Jenko KJ; Zoghbi SS; Innis RB; Cai L; Pike VW
[Ad] Endereço:Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health , Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States.
[Ti] Título:N'-3-(Trifluoromethyl)phenyl Derivatives of N-Aryl-N'-methylguanidines as Prospective PET Radioligands for the Open Channel of the N-Methyl-d-aspartate (NMDA) Receptor: Synthesis and Structure-Affinity Relationships.
[So] Source:J Med Chem;58(24):9722-30, 2015 Dec 24.
[Is] ISSN:1520-4804
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-Methyl-d-aspartate (NMDA) receptor dysfunction has been linked to several neuropsychiatric disorders, including Alzheimer's disease, epilepsy, drug addiction, and schizophrenia. A radioligand that could be used with PET to image and quantify human brain NMDA receptors in the activated "open channel" state would be useful for research on such disorders and for the development of novel therapies. To date, no radioligands have shown well-validated efficacy for imaging NMDA receptors in human subjects. In order to discover improved radioligands for PET imaging, we explored structure-affinity relationships in N'-3-(trifluoromethyl)phenyl derivatives of N-aryl-N'-methylguanidines, seeking high affinity and moderate lipophilicity, plus necessary amenability for labeling with a positron-emitter, either carbon-11 or fluorine-18. Among a diverse set of 80 prepared N'-3-(trifluoromethyl)phenyl derivatives, four of these compounds (13, 19, 20, and 36) displayed desirable low nanomolar affinity for inhibition of [(3)H](+)-MK801 at the PCP binding site and are of interest for candidate PET radioligand development.
[Mh] Termos MeSH primário: 1-Naftilamina/análogos & derivados
Guanidinas/química
Metilguanidina/análogos & derivados
Metilguanidina/química
Naftalenos/química
Compostos Radiofarmacêuticos/química
Receptores de N-Metil-D-Aspartato/metabolismo
[Mh] Termos MeSH secundário: 1-Naftilamina/química
1-Naftilamina/metabolismo
Animais
Ligação Competitiva
Radioisótopos de Carbono
Maleato de Dizocilpina/metabolismo
Radioisótopos de Flúor
Guanidinas/metabolismo
Técnicas In Vitro
Ativação do Canal Iônico
Ligantes
Metilguanidina/metabolismo
Naftalenos/metabolismo
Fenciclidina/metabolismo
Tomografia por Emissão de Pósitrons
Ensaio Radioligante
Compostos Radiofarmacêuticos/metabolismo
Ratos
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., INTRAMURAL
[Nm] Nome de substância:
0 (Carbon Radioisotopes); 0 (Fluorine Radioisotopes); 0 (Guanidines); 0 (Ligands); 0 (Naphthalenes); 0 (Radiopharmaceuticals); 0 (Receptors, N-Methyl-D-Aspartate); 5L0H5Q9VAG (Methylguanidine); 6LR8C1B66Q (Dizocilpine Maleate); 9753I242R5 (1-Naphthylamine); J1DOI7UV76 (Phencyclidine)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151121
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jmedchem.5b01510


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[PMID]:26208844
[Au] Autor:Oshima N; Onimaru H; Matsubara H; Uchida T; Watanabe A; Takechi H; Nishida Y; Kumagai H
[Ad] Endereço:Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan. Electronic address: oshima@ndmc.ac.jp.
[Ti] Título:Uric acid, indoxyl sulfate, and methylguanidine activate bulbospinal neurons in the RVLM via their specific transporters and by producing oxidative stress.
[So] Source:Neuroscience;304:133-45, 2015 Sep 24.
[Is] ISSN:1873-7544
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Patients with chronic renal failure often have hypertension, but the cause of hypertension, other than an excess of body fluid, is not well known. We hypothesized that the bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are stimulated by uremic toxins in patients with chronic renal failure. To investigate whether RVLM neurons are sensitive to uremic toxins, such as uric acid, indoxyl sulfate, or methylguanidine, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons of Wister rats using the whole-cell patch-clamp technique during superfusion with these toxins. A brainstem-spinal cord preparation that preserved the sympathetic nervous system was used for the experiments. During uric acid, indoxyl sulfate, or methylguanidine superfusion, almost all the RVLM neurons were depolarized. To examine the transporters for these toxins on RVLM neurons, histological examinations were performed. The uric acid-, indoxyl sulfate-, and methylguanidine-depolarized RVLM neurons showed the presence of urate transporter 1 (URAT 1), organic anion transporter (OAT)1 or OAT3, and organic cation transporter (OCT)3, respectively. Furthermore, the toxin-induced activities of the RVLM neurons were suppressed by the addition of an anti-oxidation drug (VAS2870, an NAD(P)H oxidase inhibitor), and a histological examination revealed the presence of NAD(P)H oxidase (nox)2 and nox4 in these RVLM neurons. The present results show that uric acid, indoxyl sulfate, and methylguanidine directly stimulate bulbospinal RVLM neurons via specific transporters on these neurons and by producing oxidative stress. These uremic toxins may cause hypertension by activating RVLM neurons.
[Mh] Termos MeSH primário: Indicã/toxicidade
Bulbo/efeitos dos fármacos
Metilguanidina/toxicidade
Neurônios/efeitos dos fármacos
Neurotoxinas/toxicidade
Ácido Úrico/toxicidade
[Mh] Termos MeSH secundário: Animais
Proteínas de Transporte de Ânions/metabolismo
Benzoxazóis/farmacologia
Inibidores Enzimáticos/farmacologia
Bulbo/patologia
Bulbo/fisiopatologia
Glicoproteínas de Membrana/antagonistas & inibidores
Glicoproteínas de Membrana/metabolismo
Potenciais da Membrana/efeitos dos fármacos
Potenciais da Membrana/fisiologia
NADPH Oxidase 2
NADPH Oxidase 4
NADPH Oxidases/antagonistas & inibidores
NADPH Oxidases/metabolismo
Neurônios/patologia
Neurônios/fisiologia
Fármacos Neuroprotetores/farmacologia
Proteína 1 Transportadora de Ânions Orgânicos/metabolismo
Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo
Estresse Oxidativo/efeitos dos fármacos
Estresse Oxidativo/fisiologia
Técnicas de Patch-Clamp
Ratos Wistar
Insuficiência Renal Crônica
Sistema Nervoso Simpático/efeitos dos fármacos
Sistema Nervoso Simpático/patologia
Sistema Nervoso Simpático/fisiopatologia
Triazóis/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (3-benzyl-7-(2-benzoxazolyl)thio-1,2,3-triazolo(4,5-d)pyrimidine); 0 (Anion Transport Proteins); 0 (Benzoxazoles); 0 (Enzyme Inhibitors); 0 (Membrane Glycoproteins); 0 (Neuroprotective Agents); 0 (Neurotoxins); 0 (Organic Anion Transport Protein 1); 0 (Organic Anion Transporters, Sodium-Independent); 0 (Slc22a6 protein, rat); 0 (Triazoles); 0 (URAT1 protein, rat); 0 (organic anion transport protein 3); 268B43MJ25 (Uric Acid); 5L0H5Q9VAG (Methylguanidine); EC 1.6.3.- (Cybb protein, rat); EC 1.6.3.- (NADPH Oxidase 2); EC 1.6.3.- (NADPH Oxidase 4); EC 1.6.3.- (NADPH Oxidases); EC 1.6.3.- (Nox4 protein, rat); N187WK1Y1J (Indican)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150726
[St] Status:MEDLINE


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[PMID]:26049456
[Au] Autor:Lotze S; Bakker HJ
[Ad] Endereço:FOM-Institute for Atomic and Molecular Physics AMOLF, Science Park 104, 1098XG Amsterdam, The Netherlands.
[Ti] Título:Structure and dynamics of a salt-bridge model system in water and DMSO.
[So] Source:J Chem Phys;142(21):212436, 2015 Jun 07.
[Is] ISSN:1089-7690
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We study the interaction between the ions methylguanidinium and trifluoroacetate dissolved in D2O and dimethylsulfoxide with linear infrared spectroscopy and femtosecond two-dimensional infrared spectroscopy. These ions constitute model systems for the side chains of arginine and glutamic and aspartic acid that are known to form salt bridges in proteins. We find that the salt-bridge formation of methylguanidinium and trifluoroacetate leads to a significant acceleration of the vibrational relaxation dynamics of the antisymmetric COO stretching vibration of the carboxyl moiety of trifluoroacetate. Salt-bridge formation has little effect on the rate of the spectral fluctuations of the CN stretching vibrations of methylguanidinium. The anisotropy of the cross peaks between the antisymmetric COO stretching vibration of trifluoroacetate and the CN stretching vibrations of methylguanidinium reveals that the salt-bridge is preferentially formed in a bidentate end-on configuration in which the two C=O groups of the carboxylate moiety form strong hydrogen bonds with the two -NH2 groups of methylguanidinium.
[Mh] Termos MeSH primário: Dimetil Sulfóxido/química
Água/química
[Mh] Termos MeSH secundário: Anisotropia
Metilguanidina/química
Modelos Moleculares
Estrutura Molecular
Sais/química
Espectrofotometria Infravermelho
Termodinâmica
Ácido Trifluoracético/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Salts); 059QF0KO0R (Water); 5L0H5Q9VAG (Methylguanidine); E5R8Z4G708 (Trifluoroacetic Acid); YOW8V9698H (Dimethyl Sulfoxide)
[Em] Mês de entrada:1603
[Cu] Atualização por classe:150608
[Lr] Data última revisão:
150608
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150608
[St] Status:MEDLINE
[do] DOI:10.1063/1.4918904


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[PMID]:25973582
[Au] Autor:Armbruster D; Happel O; Scheurer M; Harms K; Schmidt TC; Brauch HJ
[Ad] Endereço:DVGW-Technologiezentrum Wasser (TZW), Karlsruher Str. 84, 76139 Karlsruhe, Germany; University of Duisburg-Essen, Instrumental Analytical Chemistry, Universitätsstr. 5, 45141 Essen, Germany.
[Ti] Título:Emerging nitrogenous disinfection byproducts: Transformation of the antidiabetic drug metformin during chlorine disinfection of water.
[So] Source:Water Res;79:104-18, 2015 Aug 01.
[Is] ISSN:1879-2448
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:As an environmental contaminant of anthropogenic origin metformin is present in the high ng/L- up to the low µg/L-range in most surface waters. Residues of metformin may lead to the formation of disinfection by-products during chlorine disinfection, when these waters are used for drinking water production. Investigations on the underlying chemical processes occurring during treatment of metformin with sodium hypochlorite in aqueous medium led to the discovery of two hitherto unknown transformation products. Both substances were isolated and characterized by HPLC-DAD, GC-MS, HPLC-ESI-TOF, (1)H-NMR and single-crystal X-ray structure determination. The immediate major chlorination product is a cyclic dehydro-1,2,4-triazole-derivate of intense yellow color (Y; C4H6ClN5). It is a solid chlorimine of limited stability. Rapid formation was observed between 10 °C and 30 °C, as well as between pH 3 and pH 11, in both ultrapure and tap water, even at trace quantities of reactants (ng/L-range for metformin, mg/L-range for free chlorine). While Y is degraded within a few hours to days in the presence of light, elevated temperature, organic solvents and matrix constituents within tap water, a secondary degradation product was discovered, which is stable and colorless (C; C4H6ClN3). This chloroorganic nitrile has a low photolysis rate in ambient day light, while being resistant to heat and not readily degraded in the presence of organic solvents or in the tap water matrix. In addition, the formation of ammonia, dimethylamine and N,N-dimethylguanidine was verified by cation exchange chromatography.
[Mh] Termos MeSH primário: Hipoglicemiantes/química
Metformina/química
Poluentes Químicos da Água/química
Purificação da Água/métodos
[Mh] Termos MeSH secundário: Amônia/química
Dimetilaminas/química
Desinfecção
Água Potável/química
Halogenação
Metilguanidina/análogos & derivados
Metilguanidina/química
Fotólise
Hipoclorito de Sódio/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Dimethylamines); 0 (Drinking Water); 0 (Hypoglycemic Agents); 0 (Water Pollutants, Chemical); 5L0H5Q9VAG (Methylguanidine); 6145-42-2 (N,N-dimethylguanidine); 7664-41-7 (Ammonia); 9100L32L2N (Metformin); ARQ8157E0Q (dimethylamine); DY38VHM5OD (Sodium Hypochlorite)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:150526
[Lr] Data última revisão:
150526
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150515
[St] Status:MEDLINE


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[PMID]:25886160
[Au] Autor:Assis RP; Castro JF; Gutierres VO; Arcaro CA; Brotto RS; Oliveira OM; Baviera AM; Brunetti IL
[Ad] Endereço:Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Rua Expedicionários do Brasil 1621, Araraquara, CEP 14801-902, São Paulo, Brazil. renatapires_17@hotmail.com.
[Ti] Título:Effects of uremic solutes on reactive oxygen species in vitro model systems as a possibility of support the renal function management.
[So] Source:BMC Nephrol;16:50, 2015 Apr 11.
[Is] ISSN:1471-2369
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: In view of the prevalence of oxidative stress in chronic kidney disease (CKD) patients, the loss of low-molecular-weight biomolecules by hemodialysis and the antioxidant potential of some uremic solutes that accumulate in CKD, we used in vitro model systems to test the antioxidant potential of the following uremic solutes: uric acid, hippuric acid, p-cresol, phenol, methylguanidine, L-arginine, L-tyrosine, creatinine and urea. METHODS: The in vitro antioxidant efficiencies of the uremic solutes, isolated or in mixtures, were tested with the following assays: i) ABTS radical cation decolorization assay; ii) hypochlorous acid (HOCl/OCl(-)) scavenging activity; iii) superoxide anion radical (O2(•-)) scavenging activity; iv) crocin bleaching assay (capture of peroxyl radical, ROO(•)); v) hydrogen peroxide (H2O2) scavenging activity. RESULTS: Four of the tested uremic solutes (p-cresol, phenol, L-tyrosine, uric acid) were effective antioxidants and their IC50 were found in three model systems: ABTS(•+), HOCl/OCl(-) and crocin bleaching assay. In the 4-solutes mixtures, each one of the solute captured 12.5% for the IC50 of the mixture to ABTS(•+) or HOCl/OCl(-), exhibiting a virtually exact additive effect. In the 2-solutes mixtures, for ROO(•) capture, it was observed the need of more mass of uremic solutes to reach an IC50 value that was higher than the projected IC50, obtained from the IC50 of single solutes (25% of each, in the binary mixtures) in the same assay. In model systems for O2(•-) and H2O2, none of the uremic solutes showed scavenging activity. CONCLUSIONS: The use of the IC50 as an analytical tool to prepare and analyze mixtures allows the determination of their scavenging capacities and may be useful for the assessment of the antioxidant status of biological samples under conditions of altered levels of the endogenous antioxidant network and/or in the employment and monitoring of exogenous antioxidant therapy.
[Mh] Termos MeSH primário: Estresse Oxidativo/fisiologia
Espécies Reativas de Oxigênio/metabolismo
Diálise Renal/métodos
Insuficiência Renal Crônica/terapia
[Mh] Termos MeSH secundário: Arginina/metabolismo
Biomarcadores/urina
Creatinina/metabolismo
Cresóis/metabolismo
Hipuratos/metabolismo
Seres Humanos
Técnicas In Vitro
Testes de Função Renal
Metilguanidina/metabolismo
Diálise Renal/efeitos adversos
Insuficiência Renal Crônica/urina
Sensibilidade e Especificidade
Índice de Gravidade de Doença
Tirosina/metabolismo
Ureia/metabolismo
Ácido Úrico/metabolismo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Biomarkers); 0 (Cresols); 0 (Hippurates); 0 (Reactive Oxygen Species); 1MXY2UM8NV (4-cresol); 268B43MJ25 (Uric Acid); 42HK56048U (Tyrosine); 5L0H5Q9VAG (Methylguanidine); 8W8T17847W (Urea); 94ZLA3W45F (Arginine); AYI8EX34EU (Creatinine); TE0865N2ET (hippuric acid)
[Em] Mês de entrada:1601
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150418
[St] Status:MEDLINE
[do] DOI:10.1186/s12882-015-0029-1


  9 / 280 MEDLINE  
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[PMID]:25675216
[Au] Autor:Echeverria I; Papoian GA
[Ad] Endereço:Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States of America; Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, United States of America.
[Ti] Título:DNA exit ramps are revealed in the binding landscapes obtained from simulations in helical coordinates.
[So] Source:PLoS Comput Biol;11(2):e1003980, 2015 Feb.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:DNA molecules are highly charged semi-flexible polymers that are involved in a wide variety of dynamical processes such as transcription and replication. Characterizing the binding landscapes around DNA molecules is essential to understanding the energetics and kinetics of various biological processes. We present a curvilinear coordinate system that fully takes into account the helical symmetry of a DNA segment. The latter naturally allows to characterize the spatial organization and motions of ligands tracking the minor or major grooves, in a motion reminiscent of sliding. Using this approach, we performed umbrella sampling (US) molecular dynamics (MD) simulations to calculate the three-dimensional potentials of mean force (3D-PMFs) for a Na+ cation and for methyl guanidinium, an arginine analog. The computed PMFs show that, even for small ligands, the free energy landscapes are complex. In general, energy barriers of up to ~5 kcal/mol were measured for removing the ligands from the minor groove, and of ~1.5 kcal/mol for sliding along the minor groove. We shed light on the way the minor groove geometry, defined mainly by the DNA sequence, shapes the binding landscape around DNA, providing heterogeneous environments for recognition by various ligands. For example, we identified the presence of dissociation points or "exit ramps" that naturally would terminate sliding. We discuss how our findings have important implications for understanding how proteins and ligands associate and slide along DNA.
[Mh] Termos MeSH primário: DNA/química
DNA/metabolismo
DNA/ultraestrutura
[Mh] Termos MeSH secundário: Metilação de DNA
Proteínas de Ligação a DNA/química
Proteínas de Ligação a DNA/metabolismo
Metilguanidina/química
Metilguanidina/metabolismo
Simulação de Dinâmica Molecular
Conformação de Ácido Nucleico
Sódio/química
Sódio/metabolismo
Termodinâmica
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (DNA-Binding Proteins); 5L0H5Q9VAG (Methylguanidine); 9007-49-2 (DNA); 9NEZ333N27 (Sodium)
[Em] Mês de entrada:1509
[Cu] Atualização por classe:151028
[Lr] Data última revisão:
151028
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150213
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1003980


  10 / 280 MEDLINE  
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[PMID]:25499436
[Au] Autor:Naumiec GR; Cai L; Pike VW
[Ad] Endereço:Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD 20892, United States.
[Ti] Título:New N-aryl-N'-(3-(substituted)phenyl)-N'-methylguanidines as leads to potential PET radioligands for imaging the open NMDA receptor.
[So] Source:Bioorg Med Chem Lett;25(2):225-8, 2015 Jan 15.
[Is] ISSN:1464-3405
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:An expansive set of N-aryl-N'-(3-(substituted)phenyl)-N'-methylguanidines was prepared in a search for new leads to prospective PET ligands for imaging of the open channel of the N-methyl-d-aspartate (NMDA) receptor in vivo. The N-aryl rings and their substituents were varied, whereas the N-methyl group was maintained as a site for potential labeling with the positron-emitter, carbon-11 (t1/2=20.4min). At micromolar concentration, over half of the prepared compounds strongly inhibited the binding of [(3)H]TCP to its binding site in the open NMDA receptor in vitro. Four ligands displayed affinities that are similar or superior to those of the promising SPECT radioligand ([(123)I]CNS1261). The 3'-dimethylamino (19; Ki 36.7nM), 3'-trifluoromethyl (20; Ki 18.3nM) and 3'-methylthio (2; Ki 39.8nM) derivatives of N-1-naphthyl-N'-(phenyl)-N'-methylguanidine were identified as especially attractive leads for PET radioligand development.
[Mh] Termos MeSH primário: Metilguanidina/química
Tomografia por Emissão de Pósitrons
Radioisótopos/química
Receptores de N-Metil-D-Aspartato/análise
Receptores de N-Metil-D-Aspartato/química
[Mh] Termos MeSH secundário: Sítios de Ligação/fisiologia
Metilguanidina/metabolismo
Radioisótopos/metabolismo
Ensaio Radioligante/métodos
Receptores de N-Metil-D-Aspartato/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Radioisotopes); 0 (Receptors, N-Methyl-D-Aspartate); 5L0H5Q9VAG (Methylguanidine)
[Em] Mês de entrada:1509
[Cu] Atualização por classe:161025
[Lr] Data última revisão:
161025
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141216
[St] Status:MEDLINE



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