Base de dados : MEDLINE
Pesquisa : D08.811.682.655.750 [Categoria DeCS]
Referências encontradas : 1280 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 128 ir para página                         

  1 / 1280 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
[PMID]:29283238
[Au] Autor:Gusakova SV; Smagliy LV; Birulina YG; Kovalev IV; Nosarev V; Petrova IV; Reutov VP
[Ti] Título:Molecular Mechanisms of Action of Gas Transmitters NO, CO and H2S in Smooth Muscle Cells and Effect of NO-generating Compounds (Nitrates and Nitrites) on Average Life Expectancy.
[So] Source:Usp Fiziol Nauk;48(1):24-52, 2017 Jan-Mar.
[Is] ISSN:0301-1798
[Cp] País de publicação:Russia (Federation)
[La] Idioma:rus
[Ab] Resumo:Gaseous signaling molecules (gas transmitters) take an especial position among the numerous signaling molecules involved in the regulation of both intracellular processes that occur in different types of cells and cell-cell interactions. At present time, gas transmitters include three molecules whose enzymatic systems of synthesis and degradation, physiological action and intracellular effectors, the change of which under the action of gas transmitters may result in physiological and/or pathophysiological effects are well- determined. These molecules include nitrogen oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S). They are involved in the regulation of functions of various organs and systems of the human body, including the circulatory system. Interaction of NO, CO and H2S with various enzymatic and structural components of endothelial and, especially, smooth muscle cells has a significant impact on vascular tone and blood pressure. Furthermore, the crossing of NO-, CO- and H2S-mediated signaling pathways at common effectors and interaction with each other can determine the end, resulting functional response of the cell. The knowledge of the molecular targets of gas transmitters' action, the structure of the binding centers for gas transmitters and their interaction with each other may be essential in the development of methods of regulation of these signaling systems by targeted, directed action. This review summarizes the molecular mechanisms of the NO, CO and H2S interaction with the main targets, which carry out their regulatory effect on vascular smooth muscle cells. Also we describe here different ways of cross-regulation of NO-, CO- and H2S-dependent signaling pathways. We analyzed NO-synthase and nitrite reductase systems of nitric oxide cycle and discuss the nitrate-nitrite background of the existence of modern man, which can substantially modify the signaling system, the metabolism of virtually all cell ultrastructure of neurons, neuron-neuron and neuron-glial interactions and exerts its influence on socially significant diseases that can affect the quality and the average life expectancy.
[Mh] Termos MeSH primário: Monóxido de Carbono/metabolismo
Gasotransmissores/metabolismo
Sulfeto de Hidrogênio/metabolismo
Expectativa de Vida/tendências
Miócitos de Músculo Liso/efeitos dos fármacos
Doadores de Óxido Nítrico/toxicidade
Óxido Nítrico/metabolismo
[Mh] Termos MeSH secundário: Animais
Canais de Cálcio/genética
Canais de Cálcio/metabolismo
Comunicação Celular
Regulação da Expressão Gênica
Seres Humanos
Miócitos de Músculo Liso/citologia
Miócitos de Músculo Liso/metabolismo
Neuroglia/citologia
Neuroglia/efeitos dos fármacos
Neuroglia/metabolismo
Neurônios/citologia
Neurônios/efeitos dos fármacos
Neurônios/metabolismo
Óxido Nítrico Sintase Tipo III/genética
Óxido Nítrico Sintase Tipo III/metabolismo
Nitrito Redutases/genética
Nitrito Redutases/metabolismo
Transdução de Sinais
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Calcium Channels); 0 (Gasotransmitters); 0 (Nitric Oxide Donors); 31C4KY9ESH (Nitric Oxide); 7U1EE4V452 (Carbon Monoxide); EC 1.14.13.39 (NOS3 protein, human); EC 1.14.13.39 (Nitric Oxide Synthase Type III); EC 1.7.- (Nitrite Reductases); YY9FVM7NSN (Hydrogen Sulfide)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180116
[Lr] Data última revisão:
180116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171229
[St] Status:MEDLINE


  2 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28510595
[Au] Autor:Popinako A; Antonov M; Tikhonov A; Tikhonova T; Popov V
[Ad] Endereço:Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt. 33, bld. 2, Moscow, Russian Federation.
[Ti] Título:Structural adaptations of octaheme nitrite reductases from haloalkaliphilic Thioalkalivibrio bacteria to alkaline pH and high salinity.
[So] Source:PLoS One;12(5):e0177392, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Bacteria Tv. nitratireducens and Tv. paradoxus from soda lakes grow optimally in sodium carbonate/NaCl brines at pH range from 9.5 to 10 and salinity from 0.5 to 1.5 M Na+. Octaheme nitrite reductases (ONRs) from haloalkaliphilic bacteria of genus Thioalkalivibrio are stable and active in a wide range of pH (up to 11) and salinity (up to 1 M NaCl). To establish adaptation mechanisms of ONRs from haloalkaliphilic bacteria a comparative analysis of amino acid sequences and structures of ONRs from haloalkaliphilic bacteria and their homologues from non-halophilic neutrophilic bacteria was performed. The following adaptation strategies were observed: (1) strategies specific for halophilic and alkaliphilic proteins (an increase in the number of aspartate and glutamate residues and a decrease in the number of lysine residues on the protein surface), (2) strategies specific for halophilic proteins (an increase in the arginine content and a decrease in the number of hydrophobic residues on the solvent-accessible protein surface), (3) strategies specific for alkaliphilic proteins (an increase in the area of intersubunit hydrophobic contacts). Unique adaptation mechanism inherent in the ONRs from bacteria of genus Thioalkalivibrio was revealed (an increase in the core in the number of tryptophan and phenylalanine residues, and an increase in the number of small side chain residues, such as alanine and valine, in the core).
[Mh] Termos MeSH primário: Gammaproteobacteria/enzimologia
Concentração de Íons de Hidrogênio
Nitrito Redutases/química
Salinidade
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Aminoácidos/química
Sítios de Ligação
Modelos Moleculares
Conformação Molecular
Ligação Proteica
Multimerização Proteica
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); EC 1.7.- (Nitrite Reductases)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170517
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0177392


  3 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28234468
[Au] Autor:Gao B; Chi L; Mahbub R; Bian X; Tu P; Ru H; Lu K
[Ad] Endereço:Department of Environmental Health Science, University of Georgia , Athens, Georgia 30602, United States.
[Ti] Título:Multi-Omics Reveals that Lead Exposure Disturbs Gut Microbiome Development, Key Metabolites, and Metabolic Pathways.
[So] Source:Chem Res Toxicol;30(4):996-1005, 2017 Apr 17.
[Is] ISSN:1520-5010
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lead exposure remains a global public health issue, and the recent Flint water crisis has renewed public concern about lead toxicity. The toxicity of lead has been well established in a variety of systems and organs. The gut microbiome has been shown to be highly involved in many critical physiological processes, including food digestion, immune system development, and metabolic homeostasis. However, despite the key role of the gut microbiome in human health, the functional impact of lead exposure on the gut microbiome has not been studied. The aim of this study is to define gut microbiome toxicity induced by lead exposure in C57BL/6 mice using multiomics approaches, including 16S rRNA sequencing, whole genome metagenomics sequencing, and gas chromatography-mass spectrometry (GC-MS) metabolomics. 16S rRNA sequencing revealed that lead exposure altered the gut microbiome trajectory and phylogenetic diversity. Metagenomics sequencing and metabolomics profiling showed that numerous metabolic pathways, including vitamin E, bile acids, nitrogen metabolism, energy metabolism, oxidative stress, and the defense/detoxification mechanism, were significantly disturbed by lead exposure. These perturbed molecules and pathways may have important implications for lead toxicity in the host. Taken together, these results demonstrated that lead exposure not only altered the gut microbiome community structures/diversity but also greatly affected metabolic functions, leading to gut microbiome toxicity.
[Mh] Termos MeSH primário: Microbioma Gastrointestinal/efeitos dos fármacos
Trato Gastrointestinal/microbiologia
Chumbo/toxicidade
Redes e Vias Metabólicas/efeitos dos fármacos
Metaboloma/efeitos dos fármacos
[Mh] Termos MeSH secundário: Animais
Bactérias/genética
Bactérias/isolamento & purificação
Bactérias/metabolismo
Proteínas de Bactérias/metabolismo
Ácidos e Sais Biliares/metabolismo
Proteínas de Transporte/metabolismo
Metabolismo Energético/efeitos dos fármacos
Feminino
Cromatografia Gasosa-Espectrometria de Massas
Metabolômica
Camundongos
Camundongos Endogâmicos C57BL
Nitrito Redutases/metabolismo
Estresse Oxidativo/efeitos dos fármacos
RNA Ribossômico 16S/química
RNA Ribossômico 16S/genética
RNA Ribossômico 16S/metabolismo
Análise de Sequência de DNA
Vitamina E/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Bile Acids and Salts); 0 (Carrier Proteins); 0 (RNA, Ribosomal, 16S); 0 (UreE protein, Bacteria); 1406-18-4 (Vitamin E); 2P299V784P (Lead); EC 1.7.- (Nitrite Reductases)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170225
[St] Status:MEDLINE
[do] DOI:10.1021/acs.chemrestox.6b00401


  4 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28211111
[Au] Autor:Godfrey RE; Lee DJ; Busby SJW; Browning DF
[Ad] Endereço:Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
[Ti] Título:Regulation of nrf operon expression in pathogenic enteric bacteria: sequence divergence reveals new regulatory complexity.
[So] Source:Mol Microbiol;104(4):580-594, 2017 05.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The Escherichia coli K-12 nrf operon encodes a periplasmic nitrite reductase, the expression of which is driven from a single promoter, pnrf. Expression from pnrf is activated by the FNR transcription factor in response to anaerobiosis and further increased in response to nitrite by the response regulator proteins, NarL and NarP. FNR-dependent transcription is suppressed by the binding of two nucleoid associated proteins, IHF and Fis. As Fis levels increase in cells grown in rich medium, the positioning of its binding site, overlapping the promoter -10 element, ensures that pnrf is sharply repressed. Here, we investigate the expression of the nrf operon promoter from various pathogenic enteric bacteria. We show that pnrf from enterohaemorrhagic E. coli is more active than its K-12 counterpart, exhibits substantial FNR-independent activity and is insensitive to nutrient quality, due to an improved -10 element. We also demonstrate that the Salmonella enterica serovar Typhimurium core promoter is more active than previously thought, due to differences around the transcription start site, and that its expression is repressed by downstream sequences. We identify the CsrA RNA binding protein as being responsible for this, and show that CsrA differentially regulates the E. coli K-12 and Salmonella nrf operons.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Nitrito Redutases/genética
Regiões Promotoras Genéticas/genética
Proteínas de Ligação a RNA/genética
Proteínas de Ligação a RNA/metabolismo
Proteínas Repressoras/genética
Proteínas Repressoras/metabolismo
[Mh] Termos MeSH secundário: Sequência de Bases/genética
Sítios de Ligação/genética
Grupo dos Citocromos c/genética
Grupo dos Citocromos c/metabolismo
Enterobacteriaceae/metabolismo
Escherichia coli/genética
Escherichia coli K12/genética
Regulação Bacteriana da Expressão Gênica/genética
Dados de Sequência Molecular
Nitrito Redutases/metabolismo
Nitritos/metabolismo
Óperon/genética
Proteínas Periplásmicas
Fatores de Transcrição/metabolismo
Sítio de Iniciação de Transcrição
Transcrição Genética/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (CsrA protein, E coli); 0 (Cytochrome c Group); 0 (Escherichia coli Proteins); 0 (Nitrites); 0 (Periplasmic Proteins); 0 (RNA-Binding Proteins); 0 (Repressor Proteins); 0 (Transcription Factors); 9048-78-6 (cytochrome C-552); EC 1.7.- (Nitrite Reductases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170218
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13647


  5 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28192486
[Au] Autor:Li Y; Zhuang S; Wu Y; Ren H; Chen F; Lin X; Wang K; Beardall J; Gao K
[Ad] Endereço:State Key Laboratory of Marine Environmental Science (Xiamen University), College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
[Ti] Título:Ocean acidification modulates expression of genes and physiological performance of a marine diatom.
[So] Source:PLoS One;12(2):e0170970, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Ocean Acidification (OA) is known to affect various aspects of physiological performances of diatoms, but little is known about the underlining molecular mechanisms involved. Here, we show that in the model diatom Phaeodactylum tricornutum, the expression of key genes associated with photosynthetic light harvesting as well as those encoding Rubisco, carbonic anhydrase, NADH dehydrogenase and nitrite reductase, are modulated by OA (1000 µatm, pHnbs 7.83). Growth and photosynthetic carbon fixation were enhanced by elevated CO2. OA treatment decreased the expression of ß-carbonic anhydrase (ß-ca), which functions in balancing intracellular carbonate chemistry and the CO2 concentrating mechanism (CCM). The expression of the genes encoding fucoxanthin chlorophyll a/c protein (lhcf type (fcp)), mitochondrial ATP synthase (mtATP), ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit gene (rbcl) and NADH dehydrogenase subunit 2 (ndh2), were down-regulated during the first four days (< 8 generations) after the cells were transferred from LC (cells grown under ambient air condition; 390 µatm; pHnbs 8.19) to OA conditions, with no significant difference between LC and HC treatments with the time elapsed. The expression of nitrite reductase (nir) was up-regulated by the OA treatment. Additionally, the genes for these proteins (NiR, FCP, mtATP synthase, ß-CA) showed diel expression patterns. It appeared that the enhanced photosynthetic and growth rates under OA could be attributed to stimulated nitrogen assimilation, increased CO2 availability or saved energy from down-regulation of the CCM and consequently lowered cost of protein synthesis versus that of non-nitrogenous cell components.
[Mh] Termos MeSH primário: Diatomáceas/genética
Diatomáceas/metabolismo
Regulação da Expressão Gênica no Desenvolvimento
Fotossíntese/genética
[Mh] Termos MeSH secundário: Carbono/metabolismo
Dióxido de Carbono/metabolismo
Anidrases Carbônicas/genética
Clorofila/metabolismo
Diatomáceas/crescimento & desenvolvimento
Regulação para Baixo
Concentração de Íons de Hidrogênio
NADH Desidrogenase/genética
Nitrito Redutases/genética
Nitrogênio/metabolismo
Oceanos e Mares
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Ribulose-Bifosfato Carboxilase/genética
Água do Mar/química
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
1406-65-1 (Chlorophyll); 142M471B3J (Carbon Dioxide); 7440-44-0 (Carbon); EC 1.6.99.3 (NADH Dehydrogenase); EC 1.7.- (Nitrite Reductases); EC 4.1.1.39 (Ribulose-Bisphosphate Carboxylase); EC 4.2.1.1 (Carbonic Anhydrases); N762921K75 (Nitrogen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170824
[Lr] Data última revisão:
170824
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170214
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0170970


  6 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28117584
[Au] Autor:Matsuoka M; Kumar A; Muddassar M; Matsuyama A; Yoshida M; Zhang KY
[Ad] Endereço:Chemical Genomics Research Group, Center for Sustainable Resource Science, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
[Ti] Título:Discovery of Fungal Denitrification Inhibitors by Targeting Copper Nitrite Reductase from Fusarium oxysporum.
[So] Source:J Chem Inf Model;57(2):203-213, 2017 Feb 27.
[Is] ISSN:1549-960X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The efficient application of nitrogenous fertilizers is urgently required, as their excessive and inefficient use is causing substantial economic loss and environmental pollution. A significant amount of applied nitrogen in agricultural soils is lost as nitrous oxide (N O) in the environment due to the microbial denitrification process. The widely distributed fungus Fusarium oxysporum is a major denitrifier in agricultural soils and its denitrification activity could be targeted to reduce nitrogen loss in the form of N O from agricultural soils. Here, we report the discovery of first small molecule inhibitors of copper nitrite reductase (NirK) from F. oxysporum, which is a key enzyme in the fungal denitrification process. The inhibitors were discovered by a hierarchical in silico screening approach consisting of pharmacophore modeling and molecular docking. In vitro evaluation of F. oxysporum NirK activity revealed several pyrimidone and triazinone based compounds with potency in the low micromolar range. Some of these compounds suppressed the fungal denitrification in vivo as well. The compounds reported here could be used as starting points for the development of nitrogenous fertilizer supplements and coatings as a means to prevent nitrogen loss by targeting fungal denitrification.
[Mh] Termos MeSH primário: Desnitrificação/efeitos dos fármacos
Descoberta de Drogas
Inibidores Enzimáticos/farmacologia
Fusarium/efeitos dos fármacos
Fusarium/metabolismo
Nitrito Redutases/antagonistas & inibidores
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Inibidores Enzimáticos/química
Inibidores Enzimáticos/metabolismo
Simulação de Acoplamento Molecular
Nitrito Redutases/química
Nitrito Redutases/metabolismo
Conformação Proteica
Homologia de Sequência de Aminoácidos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); EC 1.7.- (Nitrite Reductases); EC 1.7.2.1 (nitrite reductase, copper-containing)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170821
[Lr] Data última revisão:
170821
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170125
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jcim.6b00649


  7 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28109837
[Au] Autor:Jensen FB; Kolind RA; Jensen NS; Montesanti G; Wang T
[Ad] Endereço:Department of Biology, University of Southern Denmark, DK-5230, Odense M, Denmark. Electronic address: fbj@biology.sdu.dk.
[Ti] Título:Interspecific variation and plasticity in hemoglobin nitrite reductase activity and its correlation with oxygen affinity in vertebrates.
[So] Source:Comp Biochem Physiol A Mol Integr Physiol;206:47-53, 2017 Apr.
[Is] ISSN:1531-4332
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Deoxygenated hemoglobin (Hb) is a nitrite reductase that reduces naturally occurring nitrite to nitric oxide (NO), supplying physiological relevant NO under hypoxic conditions. The nitrite reductase activity is modulated by the allosteric equilibrium between the R and T structures of Hb that also determines oxygen affinity. In the present study we investigated nitrite reductase activity and O affinity in Hbs from ten different vertebrate species under identical conditions to disclose interspecific variations and allow an extended test for a correlation between the rate constant for nitrite reduction and O affinity. We also tested plastic changes in Hb properties via addition of T-structure-stabilizing organic phosphates (ATP and GTP). The decay in deoxyHb during its reaction with nitrite was exponential-like in ectotherms (Atlantic hagfish, carp, crucian carp, brown trout, rainbow trout, cane toad, Indian python and red-eared slider turtle), while it was sigmoid in mammals (harbor porpoise and rabbit). Typically, hypoxia-tolerant species showed a faster reaction than intolerant species. Addition of ATP and GTP decreased O affinity and slowed the rate of nitrite reduction in a concentration-dependent manner. The initial second order rate constant of the deoxyHb-mediated nitrite reduction showed a strong curvilinear correlation with oxygen affinity among all ectothermic vertebrates, and the relationship also applied to plastic variations of Hb properties via organic phosphates. The relationship predicts high nitrite reductase activity in hypoxic tolerant species with high Hb-O affinity and reveals that the decrease in erythrocyte ATP and/or GTP during acclimation to hypoxia in ectotherms increases the erythrocyte NO generating capacity.
[Mh] Termos MeSH primário: Proteínas de Anfíbios/metabolismo
Proteínas de Peixes/metabolismo
Hemoglobinas/metabolismo
Nitrito Redutases/metabolismo
Oxigênio/metabolismo
Proteínas de Répteis/metabolismo
[Mh] Termos MeSH secundário: Aclimatação
Trifosfato de Adenosina/metabolismo
Animais
Anuros/fisiologia
Boidae/fisiologia
Hipóxia Celular
Peixes
Guanosina Trifosfato/metabolismo
Cinética
Óxido Nítrico/metabolismo
Nitritos/metabolismo
Oxirredução
Phocoena
Coelhos
Especificidade da Espécie
Tartarugas/fisiologia
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amphibian Proteins); 0 (Fish Proteins); 0 (Hemoglobins); 0 (Nitrites); 0 (Reptilian Proteins); 31C4KY9ESH (Nitric Oxide); 86-01-1 (Guanosine Triphosphate); 8L70Q75FXE (Adenosine Triphosphate); 9008-02-0 (deoxyhemoglobin); EC 1.7.- (Nitrite Reductases); S88TT14065 (Oxygen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170801
[Lr] Data última revisão:
170801
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170123
[St] Status:MEDLINE


  8 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28099525
[Au] Autor:Jani VP; Jelvani A; Moges S; Nacharaju P; Roche C; Dantsker D; Palmer A; Friedman JM; Cabrales P
[Ad] Endereço:Bioengineering, University of California San Diego, La Jolla, California, United States of America.
[Ti] Título:Polyethylene Glycol Camouflaged Earthworm Hemoglobin.
[So] Source:PLoS One;12(1):e0170041, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals' systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the colloid osmotic pressure or blood volume expansion capacity compared to LtEc, due to LtEc's already large molecular size. Taken together, these results further encourage the development of PEG-LtEc as an O2 carrying therapeutic.
[Mh] Termos MeSH primário: Hemoglobinas/química
Hemoglobinas/farmacocinética
Oligoquetos/metabolismo
Polietilenoglicóis/química
[Mh] Termos MeSH secundário: Animais
Arteríolas/efeitos dos fármacos
Velocidade do Fluxo Sanguíneo/efeitos dos fármacos
Substitutos Sanguíneos
Capilares/efeitos dos fármacos
Meia-Vida
Infusões Intravenosas
Masculino
Mesocricetus
Nitrito Redutases/química
Oxigênio/metabolismo
Vênulas/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Blood Substitutes); 0 (Hemoglobins); 0 (erythrocruorin); 30IQX730WE (Polyethylene Glycols); EC 1.7.- (Nitrite Reductases); S88TT14065 (Oxygen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170811
[Lr] Data última revisão:
170811
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170119
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0170041


  9 / 1280 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28087525
[Au] Autor:Murdock SA; Juniper SK
[Ad] Endereço:School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada smurdock@uvic.ca.
[Ti] Título:Capturing Compositional Variation in Denitrifying Communities: a Multiple-Primer Approach That Includes Epsilonproteobacteria.
[So] Source:Appl Environ Microbiol;83(6), 2017 Mar 15.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Denitrifying may dominate nitrogen loss processes in marine habitats with intense redox gradients, but assessment of their importance is limited by the currently available primers for nitrite reductase genes. Nine new primers targeting the gene of denitrifying were designed and tested for use in sequencing and quantitative PCR on two microbial mat samples (vent 2 and vent 4) from the Calypso hydrothermal vent field, Bay of Plenty, New Zealand. Commonly used and primer sets nirS1F/nirS6R, cd3aF/R3cd, nirK1F/nirK5R, and F1aCu/R3Cu were also tested to determine what may be missed by the common single-primer approach to assessing denitrifier diversity. The relative importance of in these samples was evaluated by 16S rRNA gene sequencing. represented up to 75.6% of 16S rRNA libraries, but genes from this group were not found with commonly used primers. Pairing of the new primer EPSnirS511F with either EPSnirS1100R or EPSnirS1105R recovered sequences from members of the genera , , and The new quantitative PCR primers EPSnirS103F/EPSnirS530R showed dominance of denitrifying in vent 4 compared to vent 2, which had greater representation by "standard" denitrifiers measured with the cd3aF/R3cd primers. Limited results from commonly used primers suggest biased amplification between primers. Future application of multiple and primers, including the new epsilonproteobacterial primers, will improve the detection of denitrifier diversity and the capability to identify changes in dominant denitrifying communities. Estimating the potential for increasing nitrogen limitation in the changing global ocean is reliant on understanding the microbial community that removes nitrogen through the process of denitrification. This process is favored under oxygen limitation, which is a growing global-ocean phenomenon. Current methods use the nitrite reductase genes and to assess denitrifier diversity and abundance using primers that target only a few known denitrifiers and systematically exclude denitrifying , a group known to dominate in reducing environments, such as hydrothermal vents and anoxic basins. As oxygen depletion expands in the oceans, it is important to study denitrifier community dynamics within those areas to predict future global ocean changes. This study explores the design and testing of new primers that target epsilonproteobacterial and reveals the varied success of existing primers, leading to the recommendation of a multiple-primer approach to assessing denitrifier diversity.
[Mh] Termos MeSH primário: Primers do DNA/genética
Desnitrificação/genética
Epsilonproteobacteria/genética
Epsilonproteobacteria/metabolismo
Sedimentos Geológicos/microbiologia
Fontes Hidrotermais/microbiologia
Nitrito Redutases/genética
[Mh] Termos MeSH secundário: Sequência de Bases
Desnitrificação/fisiologia
Ecossistema
Nova Zelândia
Técnicas de Amplificação de Ácido Nucleico
Oceanos e Mares
Oxigênio/metabolismo
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA Primers); 0 (RNA, Ribosomal, 16S); EC 1.7.- (Nitrite Reductases); S88TT14065 (Oxygen)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170115
[St] Status:MEDLINE


  10 / 1280 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28040856
[Au] Autor:López MF; Cabrera JJ; Salas A; Delgado MJ; López-García SL
[Ad] Endereço:Instituto de Biotecnología y Biología Molecular (IBBM), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT La Plata-CONICET, Calles 47 y 115, B1900AJL, La Plata, Argentina.
[Ti] Título:Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens.
[So] Source:Antonie Van Leeuwenhoek;110(4):531-542, 2017 Apr.
[Is] ISSN:1572-9699
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Bradyrhizobium diazoefficiens, a nitrogen-fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZ or nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. A B. diazoefficiens rpoN mutant, lacking both copies of the gene encoding the alternative sigma factor σ , was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Bradyrhizobium/metabolismo
Nitrato Redutase/metabolismo
Nitrito Redutases/metabolismo
Fator sigma/genética
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Bradyrhizobium/genética
Bradyrhizobium/crescimento & desenvolvimento
Desnitrificação/fisiologia
Nitrato Redutase/genética
Nitrito Redutases/genética
Feijão de Soja/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Sigma Factor); EC 1.7.- (Nitrite Reductases); EC 1.7.99.4 (Nitrate Reductase)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170328
[Lr] Data última revisão:
170328
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170102
[St] Status:MEDLINE
[do] DOI:10.1007/s10482-016-0821-3



página 1 de 128 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde