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Pesquisa : D04.345.566.050.111 [Categoria DeCS]
Referências encontradas : 124 [refinar]
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  1 / 124 MEDLINE  
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PMID:28456966
Autor:Uh K; Lee K
Endereço:Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA.
Título:Use of Chemicals to Inhibit DNA Replication, Transcription, and Protein Synthesis to Study Zygotic Genome Activation.
Fonte:Methods Mol Biol; 1605:191-205, 2017.
ISSN:1940-6029
País de publicação:United States
Idioma:eng
Resumo:Maternal-to-zygotic transition is an event that developmental control of early embryos is switched from oocyte-derived factors to the zygotic genome. Ability to inhibit DNA replication, transcription, and translation is an important tool in studying events, such as zygotic genome activation, during embyogenesis. Here, we describe approaches to block DNA replication, transcription, and translation using chemical inhibitors. Then we also demonstrate how the transcript level of a maternally inherited gene, ten-eleven translocation methylcytosine dioxygenase 3, responses to the chemical treatments.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Nucleic Acid Synthesis Inhibitors); 0 (Protein Synthesis Inhibitors); 98600C0908 (Cycloheximide); EC 1.13.11.- (Dioxygenases)


  2 / 124 MEDLINE  
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PMID:28898719
Autor:Li C; Wei F; Muhammad S; Yang G; Wang S; Liu X
Endereço:Food and Drug Research and Test Center, Xi'an Jiaotong University, 76# Yanta West Road, Xi'an, 710061, Shaanxi, PR China.
Título:A cost-effective LC-MS/MS method for identification and quantification of α-amanitin in rat plasma: Application to toxicokinetic study.
Fonte:J Chromatogr B Analyt Technol Biomed Life Sci; 1064:36-39, 2017 Oct 01.
ISSN:1873-376X
País de publicação:Netherlands
Idioma:eng
Resumo:α-Amanitin is the main lethal component of amanita mushrooms, and data on its toxicokinetics are few. The aim of this study was to develop a sensitive and cost-effective method to identify α-amanitin and investigate its toxicokinetic parameters using liquid chromatography-triple quadrupole tandem mass spectrometry. The colchicine was used as the internal standard (IS). The compounds were extracted from plasma samples by protein precipitation with acetonitrile (containing 1% formic acid). The analysis was performed through multiple reactions monitoring. The molecular ions and fragment ions of α-amanitin could be used as characteristic ions to perform qualitative analysis of α-amanitin. The assay was successfully validated by selectivity, linearity, matrix effect, precision and accuracy, recovery and stability according to the U.S. Food and Drug Administration Guidance, and applied to study the toxicokinetic profile of α-amanitin in rats after a single intraperitoneal administration.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin)


  3 / 124 MEDLINE  
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PMID:28887385
Autor:Radiske A; Gonzalez MC; Conde-Ocazionez SA; Feitosa A; Köhler CA; Bevilaqua LR; Cammarota M
Endereço:Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil.
Título:Prior Learning of Relevant Nonaversive Information Is a Boundary Condition for Avoidance Memory Reconsolidation in the Rat Hippocampus.
Fonte:J Neurosci; 37(40):9675-9685, 2017 Oct 04.
ISSN:1529-2401
País de publicação:United States
Idioma:eng
Resumo:Reactivated memories can be modified during reconsolidation, making this process a potential therapeutic target for posttraumatic stress disorder (PTSD), a mental illness characterized by the recurring avoidance of situations that evoke trauma-related fears. However, avoidance memory reconsolidation depends on a set of still loosely defined boundary conditions, limiting the translational value of basic research. In particular, the involvement of the hippocampus in fear-motivated avoidance memory reconsolidation remains controversial. Combining behavioral and electrophysiological analyses in male Wistar rats, we found that previous learning of relevant nonaversive information is essential to elicit the participation of the hippocampus in avoidance memory reconsolidation, which is associated with an increase in theta- and gamma-oscillation power and cross-frequency coupling in dorsal CA1 during reactivation of the avoidance response. Our results indicate that the hippocampus is involved in memory reconsolidation only when reactivation results in contradictory representations regarding the consequences of avoidance and suggest that robust nesting of hippocampal theta-gamma rhythms at the time of retrieval is a specific reconsolidation marker. Posttraumatic stress disorder (PTSD) is characterized by maladaptive avoidance responses to stimuli or behaviors that represent or bear resemblance to some aspect of a traumatic experience. Disruption of reconsolidation, the process by which reactivated memories become susceptible to modifications, is a promising approach for treating PTSD patients. However, much of what is known about fear-motivated avoidance memory reconsolidation derives from studies based on fear conditioning instead of avoidance-learning paradigms. Using a step-down inhibitory avoidance task in rats, we found that the hippocampus is involved in memory reconsolidation only when the animals acquired the avoidance response in an environment that they had previously learned as safe and showed that increased theta- and gamma-oscillation coupling during reactivation is an electrophysiological signature of this process.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Nucleic Acid Synthesis Inhibitors)


  4 / 124 MEDLINE  
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PMID:28767681
Autor:Thongbai B; Miller SL; Stadler M; Wittstein K; Hyde KD; Lumyong S; Raspé O
Endereço:Centre of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai, Thailand.
Título:Study of three interesting Amanita species from Thailand: Morphology, multiple-gene phylogeny and toxin analysis.
Fonte:PLoS One; 12(8):e0182131, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal "death caps" and "destroying angels". Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (DNA, Fungal); 0 (Mycotoxins); 17466-45-4 (Phalloidine)


  5 / 124 MEDLINE  
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PMID:28624889
Autor:Aoki M; Shimizu T
Endereço:Division of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
Título:Transcriptional control of unequal cleavage in early Tubifex embryos.
Fonte:Dev Genes Evol; 227(4):279-287, 2017 Jul.
ISSN:1432-041X
País de publicação:Germany
Idioma:eng
Resumo:Early embryos of the clitellate annelid Tubifex (oligochaete) undergo a series of unequal spiral cell divisions before the descendants of the D quadrant micromeres (cells 2d and 4d) divide bilaterally. Here, we show that inhibition of zygotic transcription by microinjection of α-amanitin (transcription inhibitor) exclusively converts unequal cleavage in cell 2d (granddaughter of 2d) into equal cleavage while other unequal cleavages and ensuing bilateral cleavages in cells 4d and 2d (great-granddaughter of 2d) all proceed in a normal fashion in the presence of this inhibitor. These results differ significantly from those reported for embryos of another clitellate annelid Helobdella (leech), in which inhibition of transcription converts bilateral (symmetric) cleavages in cells DNOPQ"' and DM" (equivalent to 2d and 4d) into unequal (asymmetric) cleavages while having no apparent effect on unequal cleavage in DNOPQ" (equivalent to 2d ). These differences imply distinct mechanisms for the control of the unequal-to-bilateral transition in the two clitellate annelids.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin)


  6 / 124 MEDLINE  
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PMID:28445845
Autor:Mináriková M; Fojtikova V; Vyskocilová E; Sedlácek J; Sikut M; Borek-Dohalska L; Stiborová M; Martinkova M
Endereço:Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic.
Título:The capacity and effectiveness of diosmectite and charcoal in trapping the compounds causing the most frequent intoxications in acute medicine: A comparative study.
Fonte:Environ Toxicol Pharmacol; 52:214-220, 2017 Jun.
ISSN:1872-7077
País de publicação:Netherlands
Idioma:eng
Resumo:The aim of the study was to compare the adsorption ability of two adsorbent materials, namely diosmectite and activated charcoal towards selected model compounds that are most commonly involved in acute intoxication. Eleven model compounds were selected: acetylsalicylic acid, α-amanitin, amlodipine, digoxin, phenobarbital, ibuprofen, imipramine, carbamazepine, oxazepam, promethazine, and theophylline. Of the tested compounds, promethazine and imipramine were the most effectively adsorbed to diosmectite. Their adsorption to diosmectite (0.356±0.029mg promethazine/mg diosmectite and 0.354±0.019mg imipramine/mg diosmectite, respectively) was significantly higher than their adsorption to activated charcoal. The effect of temperature and pH on the adsorption efficiencies was also evaluated. In the case of experiments with mixture of both adsorbents, they mostly behaved in a solution independently or in a slightly antagonistic way. Using various methods such as N adsorption and thermogravimetric analysis, the structure and texture of diosmectite and activated charcoal were attained.
Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Antidotes); 0 (Silicates); 16291-96-6 (Charcoal); 1J444QC288 (Amlodipine); 33CM23913M (Carbamazepine); 6GOW6DWN2A (Oxazepam); 73K4184T59 (Digoxin); A3N5ZCN45C (Smectite); C137DTR5RG (Theophylline); FF28EJQ494 (Promethazine); OGG85SX4E4 (Imipramine); R16CO5Y76E (Aspirin); WK2XYI10QM (Ibuprofen); YQE403BP4D (Phenobarbital)


  7 / 124 MEDLINE  
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PMID:28292928
Autor:Weems JC; Slaughter BD; Unruh JR; Boeing S; Hall SM; McLaird MB; Yasukawa T; Aso T; Svejstrup JQ; Conaway JW; Conaway RC
Endereço:From the Stowers Institute for Medical Research, Kansas City, Missouri 64110.
Título:Cockayne syndrome B protein regulates recruitment of the Elongin A ubiquitin ligase to sites of DNA damage.
Fonte:J Biol Chem; 292(16):6431-6437, 2017 Apr 21.
ISSN:1083-351X
País de publicação:United States
Idioma:eng
Resumo:Elongin A performs dual functions as the transcriptionally active subunit of RNA polymerase II (Pol II) elongation factor Elongin and as the substrate recognition subunit of a Cullin-RING E3 ubiquitin ligase that ubiquitylates Pol II in response to DNA damage. Assembly of the Elongin A ubiquitin ligase and its recruitment to sites of DNA damage is a tightly regulated process induced by DNA-damaging agents and α-amanitin, a drug that induces Pol II stalling. In this study, we demonstrate (i) that Elongin A and the ubiquitin ligase subunit CUL5 associate in cells with the Cockayne syndrome B (CSB) protein and (ii) that this interaction is also induced by DNA-damaging agents and α-amanitin. In addition, we present evidence that the CSB protein promotes stable recruitment of the Elongin A ubiquitin ligase to sites of DNA damage. Our findings are consistent with the model that the Elongin A ubiquitin ligase and the CSB protein function together in a common pathway in response to Pol II stalling and DNA damage.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (CUL5 protein, human); 0 (Cullin Proteins); 0 (ELOA protein, human); 0 (Elongin); 0 (Poly-ADP-Ribose Binding Proteins); 0 (Transcription Factors); 147336-22-9 (Green Fluorescent Proteins); EC 2.3.2.27 (Ubiquitin-Protein Ligases); EC 2.7.7.- (RNA Polymerase II); EC 3.6.4.- (DNA Helicases); EC 3.6.4.12 (ERCC6 protein, human); EC 6.5.1.- (DNA Repair Enzymes)


  8 / 124 MEDLINE  
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PMID:28241077
Autor:Mitchell CL; Latuszek CE; Vogel KR; Greenlund IM; Hobmeier RE; Ingram OK; Dufek SR; Pecore JL; Nip FR; Johnson ZJ; Ji X; Wei H; Gailing O; Werner T
Endereço:Department of Biological Sciences, Michigan Technological University, 1400 Townsend Dr., Houghton, MI, United States of America.
Título:α-amanitin resistance in Drosophila melanogaster: A genome-wide association approach.
Fonte:PLoS One; 12(2):e0173162, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:We investigated the mechanisms of mushroom toxin resistance in the Drosophila Genetic Reference Panel (DGRP) fly lines, using genome-wide association studies (GWAS). While Drosophila melanogaster avoids mushrooms in nature, some lines are surprisingly resistant to α-amanitin-a toxin found solely in mushrooms. This resistance may represent a pre-adaptation, which might enable this species to invade the mushroom niche in the future. Although our previous microarray study had strongly suggested that pesticide-metabolizing detoxification genes confer α-amanitin resistance in a Taiwanese D. melanogaster line Ama-KTT, none of the traditional detoxification genes were among the top candidate genes resulting from the GWAS in the current study. Instead, we identified Megalin, Tequila, and widerborst as candidate genes underlying the α-amanitin resistance phenotype in the North American DGRP lines, all three of which are connected to the Target of Rapamycin (TOR) pathway. Both widerborst and Tequila are upstream regulators of TOR, and TOR is a key regulator of autophagy and Megalin-mediated endocytosis. We suggest that endocytosis and autophagy of α-amanitin, followed by lysosomal degradation of the toxin, is one of the mechanisms that confer α-amanitin resistance in the DGRP lines.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Drosophila Proteins); 0 (Low Density Lipoprotein Receptor-Related Protein-2); 0 (Pesticides); 63231-63-0 (RNA); EC 2.7.1.1 (TOR Serine-Threonine Kinases)


  9 / 124 MEDLINE  
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PMID:27910775
Autor:Wu H; Tang S; Huang Z; Zhou Q; Zhang P; Chen Z
Endereço:Life Science College, Hunan Normal University, Changsha, China.
Título:Hepatoprotective Effects and Mechanisms of Action of Triterpenoids from Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) on α-Amanitin-Induced Liver Injury in Mice.
Fonte:Int J Med Mushrooms; 18(9):841-850, 2016.
ISSN:1940-4344
País de publicação:United States
Idioma:eng
Resumo:Most fatal mushroom poisonings are caused by species of the genus Amanita; the amatoxins are responsible for acute liver failure and death in humans. Ganoderma lucidum is a well-known traditional medicinal mushroom that has been shown to have obvious hepatoprotective effects. This study evaluated the hepatoprotective effects of triterpenoids from G. lucidum on liver injury induced by a-amanitin (α-AMA) in mice and the mechanisms of action of these triterpenoids, including radical scavenging and antiapoptosis activities. Mice were treated with α-AMA, followed by G. lucidum total triterpenoids or individual triterpenoids, and their hepatoprotective effects were compared with those of the reference drug silibinin (SIL). Treatment with SIL, G. lucidum total triterpenoids, and each of the 5 individual triterpenoids significantly reduced serum alanine aminotransaminase and aspartate ami- notransaminase concentrations and reduced mortality rates 20-40%. Moreover, triterpenoids and SIL significantly enhanced superoxide dismutase and catalase activity and reduced malondialdehyde content in livers. Treatment with ganoderic acid C2 significantly inhibited DNA fragmentation and decreased caspase-3, -8, and -9 activities. The results demonstrated that triterpenoids have hepatoprotective effects on α-AMA-induced liver injury and that their hepatoprotective mechanisms may be the result of their antioxidative and radical scavenging activities and their inhibition of apoptosis.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Triterpenes); EC 2.6.1.1 (Aspartate Aminotransferases); EC 2.6.1.2 (Alanine Transaminase)


  10 / 124 MEDLINE  
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PMID:27394089
Autor:Tan L; He R; Li Y; Liang Y; Li H; Tang Y
Endereço:MOE Key Laboratory of Laser Life Science, South China Normal University, Guangzhou 510006, China; Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China. Electronic address: jsutanlei@gmail.com.
Título:Fabrication of a biomimetic adsorbent imprinted with a common specificity determinant for the removal of α- and ß-amanitin from plasma.
Fonte:J Chromatogr A; 1459:1-8, 2016 Aug 12.
ISSN:1873-3778
País de publicação:Netherlands
Idioma:eng
Resumo:α-Amanitin and ß-amanitin are the main toxins of mushroom poisoning. The application of traditional non-selective adsorbents is not satisfactory in clinical treatment of amanita mushroom poisoning due to lack of specificity adsorption capability of these adsorbents toward amanitin toxins. In the current work, we introduce a novel molecularly imprinted biomimetic adsorbent based on a ligand specificity determinant through surface imprinted strategy. Owing to the expensive price of the amanitin sources, we selected a typical common moiety of α, ß-amanitin as specificity determinant to synthesize a template necessary for the preparation of molecularly imprinted polymers (MIPs). Computer simulation was used to initially select acidic methacrylic acid (MAA) and basic 4-vinyl pyridine (4-VP) together as functional monomers. The experiments further demonstrated that the synergistic interaction of MAA and 4-VP played a primary role in the recognition of α, ß-amanitin by MIPs. By means of batch and packed-bed column experiment and the hemocompatibility evaluation, the resultant biomimetic adsorbent has been proved to be capable of selectively removing α, ß-amanitin and possess good hemocompatibility. This novel adsorbent has great potential to find application in human plasma purification.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Alpha-Amanitin); 0 (Amanitins); 0 (Polymers); 21150-22-1 (beta-amanitin); 7631-86-9 (Silicon Dioxide)



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