Base de dados : MEDLINE
Pesquisa : D09.698.718 [Categoria DeCS]
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[PMID]:28450249
[Au] Autor:Kurt A; Toker OS; Tornuk F
[Ad] Endereço:Department of Food Engineering, Engineering Faculty, Ondokuz Mayis University, 55139, Samsun, Turkey; Department of Food Engineering, Engineering and Architecture Faculty, Bitlis Eren University, 13000 Bitlis, Turkey. Electronic address: abdullahkurt48@gmail.com.
[Ti] Título:Effect of xanthan and locust bean gum synergistic interaction on characteristics of biodegradable edible film.
[So] Source:Int J Biol Macromol;102:1035-1044, 2017 Sep.
[Is] ISSN:1879-0003
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The present study was aimed to use different combinations of xanthan (XG) and locust bean gum (LBG) in the biodegradable edible film preparation by benefitting from their synergistic interactions for the first time. Concentrations of LBG, XG and glycerol of the optimized film sample were found to be 89.6%, 10.4% and 20%, respectively. At the optimum point the WVP, TS, E% and EM values of film were found 0.22gmmh m kPa, 86.97MPa, 33.34% and 177.25MPa, respectively. The optimized film was characterized for its physical, thermal and structural behavior. The scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR) analyses exhibited miscibility and presence of interaction between polymers. In conclusion, XG and LBG interaction was used successfully to get biodegradable films and coatings with improved characteristics.
[Mh] Termos MeSH primário: Materiais Biocompatíveis/química
Galactanos/química
Mananas/química
Gomas Vegetais/química
Polissacarídeos Bacterianos/química
Embalagem de Produtos
[Mh] Termos MeSH secundário: Materiais Biocompatíveis/metabolismo
Composição de Medicamentos
Glicerol/química
Fenômenos Mecânicos
Permeabilidade
Reologia
Vapor
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biocompatible Materials); 0 (Galactans); 0 (Mannans); 0 (Plant Gums); 0 (Polysaccharides, Bacterial); 0 (Steam); PDC6A3C0OX (Glycerol); TTV12P4NEE (xanthan gum); V4716MY704 (locust bean gum)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE


  2 / 16200 MEDLINE  
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[PMID]:28461446
[Au] Autor:Pequegnat B; Laird RM; Ewing CP; Hill CL; Omari E; Poly F; Monteiro MA; Guerry P
[Ad] Endereço:Department of Chemistry, University of Guelph, Guelph, Ontario, Canada.
[Ti] Título:Phase-Variable Changes in the Position of -Methyl Phosphoramidate Modifications on the Polysaccharide Capsule of Campylobacter jejuni Modulate Serum Resistance.
[So] Source:J Bacteriol;199(14), 2017 07 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:polysaccharide capsules (CPS) are characterized by the presence of nonstoichiometric -methyl phosphoramidate (MeOPN) modifications. The lack of stoichiometry is due to phase variation at homopolymeric tracts within the MeOPN transferase genes. strain 81-176 contains two MeOPN transferase genes and has been shown previously to contain MeOPN modifications at the 2 and 6 positions of the galactose (Gal) moiety in the CPS. We demonstrate here that one of the two MeOPN transferases, encoded by CJJ81176_1435, is bifunctional and is responsible for the addition of MeOPN to both the 2 and the 6 positions of Gal. A new MeOPN at the 4 position of Gal was observed in a mutant lacking the CJJ81176_1435 transferase and this was encoded by the CJJ81176_1420 transferase. During routine growth of 81-176, the CJJ81176_1420 transferase was predominantly in an off configuration, while the CJJ81176_1435 transferase was primarily on. However, exposure to normal human serum selected for cells expressing the CJJ81176_1420 transferase. MeOPN modifications appear to block binding of naturally occurring antibodies to the 81-176 CPS. The absence of MeOPN-4-Gal resulted in enhanced sensitivity to serum killing, whereas the loss of MeOPN-2-Gal and MeOPN-6-Gal resulted in enhanced resistance to serum killing, perhaps by allowing more MeOPN to be put onto the 4 position of Gal. undergoes phase variation in genes encoding surface antigens, leading to the concept that a strain of this organism consists of multiple genotypes that are selected for fitness in various environments. Methyl phosphoramidate modifications on the capsule of block access of preexisting antibodies in normal human sera to the polysaccharide chain, thus preventing activation of the classical arm of the complement cascade. We show that the capsule of strain 81-176 contains more sites of MeOPN modifications than previously recognized and that one site, on the 4 position of galactose, is more critical to complement resistance than the others. Exposure to normal human serum selects for variants in the population expressing this MeOPN modification.
[Mh] Termos MeSH primário: Amidas
Cápsulas Bacterianas/fisiologia
Campylobacter jejuni/metabolismo
Soros Imunes/imunologia
Ácidos Fosfóricos
Polissacarídeos Bacterianos/metabolismo
[Mh] Termos MeSH secundário: Animais
Anticorpos Antibacterianos
Clonagem Molecular
Regulação Bacteriana da Expressão Gênica/fisiologia
Epitopos Imunodominantes
Mutação
Polissacarídeos Bacterianos/química
Polissacarídeos Bacterianos/imunologia
Coelhos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amides); 0 (Antibodies, Bacterial); 0 (Immune Sera); 0 (Immunodominant Epitopes); 0 (Phosphoric Acids); 0 (Polysaccharides, Bacterial); 9Q189608GB (phosphoramidic acid)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:180306
[Lr] Data última revisão:
180306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE


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[PMID]:28448633
[Au] Autor:Scoffield JA; Duan D; Zhu F; Wu H
[Ad] Endereço:Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
[Ti] Título:A commensal streptococcus hijacks a Pseudomonas aeruginosa exopolysaccharide to promote biofilm formation.
[So] Source:PLoS Pathog;13(4):e1006300, 2017 Apr.
[Is] ISSN:1553-7374
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Pseudomonas aeruginosa causes devastating chronic pulmonary infections in cystic fibrosis (CF) patients. Although the CF airway is inhabited by diverse species of microorganisms interlaced within a biofilm, many studies focus on the sole contribution of P. aeruginosa pathogenesis in CF morbidity. More recently, oral commensal streptococci have been identified as cohabitants of the CF lung, but few studies have explored the role these bacteria play within the CF biofilm. We examined the interaction between P. aeruginosa and oral commensal streptococci within a dual species biofilm. Here we report that the CF P. aeruginosa isolate, FRD1, enhances biofilm formation and colonization of Drosophila melanogaster by the oral commensal Streptococcus parasanguinis. Moreover, production of the P. aeruginosa exopolysaccharide, alginate, is required for the promotion of S. parasanguinis biofilm formation and colonization. However, P. aeruginosa is not promoted in the dual species biofilm. Furthermore, we show that the streptococcal adhesin, BapA1, mediates alginate-dependent enhancement of the S. parasanguinis biofilm in vitro, and BapA1 along with another adhesin, Fap1, are required for the in vivo colonization of S. parasanguinis in the presence of FRD1. Taken together, our study highlights a new association between streptococcal adhesins and P. aeruginosa alginate, and reveals a mechanism by which S. parasanguinis potentially colonizes the CF lung and interferes with the pathogenesis of P. aeruginosa.
[Mh] Termos MeSH primário: Biofilmes
Fibrose Cística/microbiologia
Polissacarídeos Bacterianos/metabolismo
Infecções por Pseudomonas/microbiologia
Pseudomonas aeruginosa/fisiologia
[Mh] Termos MeSH secundário: Adesinas Bacterianas/genética
Adesinas Bacterianas/metabolismo
Animais
Drosophila melanogaster
Seres Humanos
Pseudomonas aeruginosa/genética
Pseudomonas aeruginosa/crescimento & desenvolvimento
Pseudomonas aeruginosa/isolamento & purificação
Sistema Respiratório/microbiologia
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Adhesins, Bacterial); 0 (Polysaccharides, Bacterial); 128531-82-8 (exopolysaccharide, Pseudomonas)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:180306
[Lr] Data última revisão:
180306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170428
[St] Status:MEDLINE
[do] DOI:10.1371/journal.ppat.1006300


  4 / 16200 MEDLINE  
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[PMID]:29352301
[Au] Autor:Shah BS; Ashwood HE; Harrop SJ; Farrugia DN; Paulsen IT; Mabbutt BC
[Ad] Endereço:Department of Molecular Sciences, Macquarie University, Sydney, Australia.
[Ti] Título:Crystal structure of a UDP-GlcNAc epimerase for surface polysaccharide biosynthesis in Acinetobacter baumannii.
[So] Source:PLoS One;13(1):e0191610, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:With new strains of Acinetobacter baumannii undergoing genomic analysis, it has been possible to define regions of genomic plasticity (RGPs), encoding specific adaptive elements. For a selected RGP from a community-derived isolate of A. baumannii, we outline sequences compatible with biosynthetic machinery of surface polysaccharides, specifically enzymes utilized in the dehydration and conversion of UDP-N-acetyl-D-glucosamine (UDP-D-GlcNAc). We have determined the crystal structure of one of these, the epimerase Ab-WbjB. This dehydratase belongs to the 'extended' short-chain dehydrogenase/reductase (SDR) family, related in fold to previously characterised enzymes CapE and FlaA1. Our 2.65Å resolution structure of Ab-WbjB shows a hexamer, organised into a trimer of chain pairs, with coenzyme NADP+ occupying each chain. Specific active-site interactions between each coenzyme and a lysine quaternary group of a neighbouring chain interconnect adjacent dimers, so stabilising the hexameric form. We show UDP-GlcNAc to be a specific substrate for Ab-WbjB, with binding evident by ITC (Ka = 0.23 µmol-1). The sequence of Ab-WbjB shows variation from the consensus active-site motifs of many SDR enzymes, demonstrating a likely catalytic role for a specific threonine sidechain (as an alternative to tyrosine) in the canonical active site chemistry of these epimerases.
[Mh] Termos MeSH primário: Acinetobacter baumannii/enzimologia
Proteínas de Bactérias/química
Carboidratos Epimerases/química
[Mh] Termos MeSH secundário: Acinetobacter baumannii/genética
Acinetobacter baumannii/isolamento & purificação
Sequência de Aminoácidos
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Carboidratos Epimerases/genética
Carboidratos Epimerases/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Seres Humanos
Modelos Moleculares
Polissacarídeos Bacterianos/biossíntese
Conformação Proteica
Domínios Proteicos
Estrutura Quaternária de Proteína
Homologia de Sequência de Aminoácidos
Eletricidade Estática
Homologia Estrutural de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Polysaccharides, Bacterial); EC 5.1.3.- (Carbohydrate Epimerases)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180121
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191610


  5 / 16200 MEDLINE  
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[PMID]:29406121
[Au] Autor:Wang L; Wang L; Shi Q; Yu H
[Ad] Endereço:State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China.
[Ti] Título:Purification and molecular weight distribution of a key exopolysaccharide component of Bacillus megaterium TF10.
[So] Source:J Environ Sci (China);63:9-15, 2018 Jan.
[Is] ISSN:1001-0742
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Extracellular polymeric substances (EPS) are organic metabolic compounds excreted by microorganisms. They largely impact microbial aggregate structures and functions. Extracellular polysaccharides (EP) in EPS are responsible for the formation of microbial aggregates. In this work, we successfully separated and characterized EP from EPS of the bacterium Bacillus megaterium TF10. Extraction of EP from EPS was optimized using Sevag's reagent. Chemical characteristics, functional groups, and molecular weight (MW) distribution of EP were compared with the harvested EPS and soluble microbial products (SMP). We found that the polymers of lower MW and free proteins were successfully removed by Sevag's reagent. The higher MW components of EPS were predominantly polysaccharides, while the polymers of lower MW tended to secrete to the supernatant and were described as SMP. A part of the proteins in the EP was polysaccharide-bonded. Our results can be further used in elucidating the complex flocculation mechanisms in which EP play a major role.
[Mh] Termos MeSH primário: Bacillus megaterium/fisiologia
Polímeros/química
Polissacarídeos Bacterianos/química
[Mh] Termos MeSH secundário: Transporte Biológico
Floculação
Peso Molecular
Polímeros/metabolismo
Polissacarídeos Bacterianos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Polymers); 0 (Polysaccharides, Bacterial); 0 (exopolysaccharide, Bacillus)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180216
[Lr] Data última revisão:
180216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180207
[St] Status:MEDLINE


  6 / 16200 MEDLINE  
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[PMID]:29406116
[Au] Autor:Nguyen TN; Chen PC; Huang C
[Ad] Endereço:Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Chinese Taipei.
[Ti] Título:Nitrate removal and extracellular polymeric substances of autohydrogenotrophic bacteria under various pH and hydrogen flow rates.
[So] Source:J Environ Sci (China);63:50-57, 2018 Jan.
[Is] ISSN:1001-0742
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:In recent years there has been an increasing interest in the use of autohydrogenotrophic bacteria to treat nitrate from wastewater. However, our knowledge about the characteristics of extracellular polymeric substances (EPS) releasing by these activities is not yet very advanced. This study aimed to investigate the change in EPS compositions under various pH values and hydrogen flow rates, taking into consideration nitrogen removal. Results showed that pH7.5 and a hydrogen flow rate of 90mL/min were the optimal operating conditions, resulting in 100% nitrogen removal after 6hr of operation. Soluble and bound polysaccharides decreased, while bound proteins increased with increasing pH. Polysaccharides increased with increasing hydrogen flow rate. No significant change of bound proteins was observed at various hydrogen flow rates.
[Mh] Termos MeSH primário: Polissacarídeos Bacterianos/química
Eliminação de Resíduos Líquidos/métodos
Águas Residuais/química
[Mh] Termos MeSH secundário: Bactérias
Hidrogênio/química
Concentração de Íons de Hidrogênio
Nitratos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nitrates); 0 (Polysaccharides, Bacterial); 0 (Waste Water); 7YNJ3PO35Z (Hydrogen)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180216
[Lr] Data última revisão:
180216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180207
[St] Status:MEDLINE


  7 / 16200 MEDLINE  
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[PMID]:29372802
[Au] Autor:Petrova LP; Prilipov AG; Katsy EI
[Ti] Título:[Detection of putative polysaccharide biosynthesis genes in Azospirillum brasilense strains from serogroups I and II].
[So] Source:Genetika;53(1):31-42, 2017 Jan.
[Is] ISSN:0016-6758
[Cp] País de publicação:Russia (Federation)
[La] Idioma:rus
[Ab] Resumo:It is known that in Azospirillum brasilense strains Sp245 and SR75 included in serogroup I, the repeat units of their O-polysaccharides consist of five residues of D-rhamnose, and in strain SR15, of four; and the heteropolymeric O-polysaccharide of A. brasilense type strain Sp7 from serogroup II contains not less than five types of repeat units. In the present work, a complex of nondegenerate primers to the genes of A. brasilense Sp245 plasmids AZOBR_p6, AZOBR_p3, and AZOBR_p2, which encode putative enzymes for the biosynthesis of core oligosaccharide and O-polysaccharide of lipopolysaccharide, capsular polysaccharides, and exopolysaccharides, was proposed. By using the designed primers, products of the expected sizes were synthesized in polymerase chain reactions on genomic DNA of A. brasilense Sp245, SR75, SR15, and Sp7 in 36, 29, 23, and 12 cases, respectively. As a result of sequencing of a number of amplicons, a high (86­99%) level of identity of the corresponding putative polysaccharide biosynthesis genes in three A. brasilense strains from serogroup I was detected. In a blotting-hybridization reaction with the biotin-labeled DNA of the A. brasilense gene AZOBR_p60122 coding for putative permease of the ABC transporter of polysaccharides, localization of the homologous gene in ~120-MDa plasmids of the bacteria A. brasilense SR15 and SR75 was revealed.
[Mh] Termos MeSH primário: Azospirillum brasilense
DNA Bacteriano
Genes Bacterianos/fisiologia
Genoma Bacteriano/fisiologia
Plasmídeos
Polissacarídeos Bacterianos
Sorogrupo
[Mh] Termos MeSH secundário: Azospirillum brasilense/genética
Azospirillum brasilense/metabolismo
DNA Bacteriano/genética
DNA Bacteriano/metabolismo
Plasmídeos/genética
Plasmídeos/metabolismo
Polissacarídeos Bacterianos/biossíntese
Polissacarídeos Bacterianos/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (Polysaccharides, Bacterial)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180216
[Lr] Data última revisão:
180216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180127
[St] Status:MEDLINE


  8 / 16200 MEDLINE  
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[PMID]:29025664
[Au] Autor:Tsai W; Tsai H; Wong Y; Hong J; Chang S; Lee M
[Ad] Endereço:Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Taiwan.
[Ti] Título:Preparation and characterization of gellan gum/glucosamine/clioquinol film as oral cancer treatment patch.
[So] Source:Mater Sci Eng C Mater Biol Appl;82:317-322, 2018 Jan 01.
[Is] ISSN:1873-0191
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:To administer cancer drugs with improved convenience to patients and to enhance the bioavailability of cancer drugs for oral cancer therapy, this study prepared gellan gum/glucosamine/clioquinol (GG/GS/CQ) film as the oral cancer treatment patch. GG/GS/CQ film fabricated through the EDC-mediated coupling reactions (GG/GS/CQ/EDC film). The film of the physicochemical properties and drug release kinetics were studied. The effectiveness of GG/GS/CQ/EDC film as oral cancer treatment patch were evaluated with the animal model. The results confirmed that CQ can be incorporated via EDC-mediated covalent conjugation to gellan gum/glucosamine. Mechanical testing revealed that the maximum tensile strength and elongation percentage at break were 1.91kgf/mm and 5.01% for GG/GS/CQ/EDC film. After a drug release experiment lasting 45days, 86.8% of CQ was released from GG/GS/CQ/EDC film. The Huguchi model fit the GG/GS/CQ/EDC drug release data with high correlation coefficients (R =0.9994, respectively). The effect of the CQ dose on oral cancer cells (OC-2) was tested, and the IC of CQ alone and CQ with 10µM CuCl were 9.59 and 2.22µM, respectively. The animal testing indicated that GG/GS/CQ/EDC film was decreased epidermal growth factor receptor (EGFR) expression and suppress tumor progression. These findings provide insights into a possible use for GG/GS/CQ/EDC film for oral ca in clinical practice. The GG/GS/CQ/EDC film is suitable as the dressing for use in the treatment of early-stage cancer or as wound care after surgery in late-stage of oral cancer treatment.
[Mh] Termos MeSH primário: Antineoplásicos/química
Clioquinol/química
Portadores de Fármacos/química
Glucosamina/química
Polissacarídeos Bacterianos/química
[Mh] Termos MeSH secundário: 9,10-Dimetil-1,2-benzantraceno/toxicidade
Animais
Antineoplásicos/uso terapêutico
Antineoplásicos/toxicidade
Carbodi-Imidas/química
Linhagem Celular Tumoral
Sobrevivência Celular/efeitos dos fármacos
Clioquinol/uso terapêutico
Clioquinol/toxicidade
Cobre/química
Cobre/toxicidade
Cricetinae
Modelos Animais de Doenças
Liberação Controlada de Fármacos
Seres Humanos
Neoplasias Bucais/induzido quimicamente
Neoplasias Bucais/tratamento farmacológico
Neoplasias Bucais/patologia
Receptor do Fator de Crescimento Epidérmico/metabolismo
Espectroscopia de Infravermelho com Transformada de Fourier
Resistência à Tração
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antineoplastic Agents); 0 (Carbodiimides); 0 (Drug Carriers); 0 (Polysaccharides, Bacterial); 141650-20-6 (1-ethyl-3-(3-dimethylaminoethyl)carbodiimide); 57-97-6 (9,10-Dimethyl-1,2-benzanthracene); 7593U09I4D (gellan gum); 789U1901C5 (Copper); 7BHQ856EJ5 (Clioquinol); EC 2.7.10.1 (Receptor, Epidermal Growth Factor); N08U5BOQ1K (Glucosamine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180205
[Lr] Data última revisão:
180205
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171014
[St] Status:MEDLINE


  9 / 16200 MEDLINE  
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[PMID]:29287062
[Au] Autor:Arcuri M; Di Benedetto R; Cunningham AF; Saul A; MacLennan CA; Micoli F
[Ad] Endereço:GSK Vaccines Institute for Global Health (GVGH), Siena, Italy.
[Ti] Título:The influence of conjugation variables on the design and immunogenicity of a glycoconjugate vaccine against Salmonella Typhi.
[So] Source:PLoS One;12(12):e0189100, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In recent years there have been major efforts to develop glycoconjugate vaccines based on the Vi polysaccharide that will protect against Salmonella enterica Typhi infections, particularly typhoid fever, which remains a major public health concern in low-income countries. The design of glycoconjugate vaccines influences the immune responses they elicit. Here we systematically test the response in mice to Vi glycoconjugates that differ in Vi chain length (full-length and fragmented), carrier protein, conjugation chemistry, saccharide to protein ratio and size. We show that the length of Vi chains, but not the ultimate size of the conjugate, has an impact on the anti-Vi IgG immune response induced. Full-length Vi conjugates, independent of the carrier protein, induce peak IgG responses rapidly after just one immunization, and secondary immunization does not enhance the magnitude of these responses. Fragmented Vi linked to CRM197 and diphtheria toxoid, but not to tetanus toxoid, gives lower anti-Vi antibody responses after the first immunization than full-length Vi conjugates, but antibody titres are similar to those induced by full-length Vi conjugates following a second dose. The chemistry to conjugate Vi to the carrier protein, the linker used, and the saccharide to protein ratio do not significantly alter the response. We conclude that Vi length and carrier protein are the variables that influence the anti-Vi IgG response to immunization the most, while other parameters are of lesser importance.
[Mh] Termos MeSH primário: Glicoconjugados/imunologia
Salmonella typhi/imunologia
Vacinas Tíficas-Paratíficas/imunologia
Vacinas Conjugadas/imunologia
[Mh] Termos MeSH secundário: Animais
Proteínas de Bactérias/imunologia
Imunoglobulina G/imunologia
Camundongos
Polissacarídeos Bacterianos/imunologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Glycoconjugates); 0 (Immunoglobulin G); 0 (Polysaccharides, Bacterial); 0 (Typhoid-Paratyphoid Vaccines); 0 (Vaccines, Conjugate)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180129
[Lr] Data última revisão:
180129
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171230
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189100


  10 / 16200 MEDLINE  
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[PMID]:28468829
[Au] Autor:Kuttel MM; Cescutti P; Distefano M; Rizzo R
[Ad] Endereço:From the Department of Computer Science, University of Cape Town, Rondebosch 7701, South Africa and.
[Ti] Título:Fluorescence and NMR spectroscopy together with molecular simulations reveal amphiphilic characteristics of a biofilm exopolysaccharide.
[So] Source:J Biol Chem;292(26):11034-11042, 2017 06 30.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Biofilms are a collective mode of bacterial life in which a self-produced matrix confines cells in close proximity to each other. Biofilms confer many advantages, including protection from chemicals (including antibiotics), entrapment of useful extracellular enzymes and nutrients, as well as opportunities for efficient recycling of molecules from dead cells. Biofilm matrices are aqueous gel-like structures composed of polysaccharides, proteins, and DNA stabilized by intermolecular interactions that may include non-polar connections. Recently, polysaccharides extracted from biofilms produced by species of the complex were shown to possess clusters of rhamnose, a 6-deoxy sugar with non-polar characteristics. Molecular dynamics simulations are well suited to characterizing the structure and dynamics of polysaccharides, but only relatively few such studies exist of their interaction with non-polar molecules. Here we report an investigation into the hydrophobic properties of the exopolysaccharide produced by strain C1576. Fluorescence experiments with two hydrophobic fluorescent probes established that this polysaccharide complexes hydrophobic species, and NMR experiments confirmed these interactions. Molecular simulations to model the hydrodynamics of the polysaccharide and the interaction with guest species revealed a very flexible, amphiphilic carbohydrate chain that has frequent dynamic interactions with apolar molecules; both hexane and a long-chain fatty acid belonging to the quorum-sensing system of were tested. A possible role of the non-polar domains of the exopolysaccharide in facilitating the diffusion of aliphatic species toward specific targets within the biofilm aqueous matrix is proposed.
[Mh] Termos MeSH primário: Biofilmes/crescimento & desenvolvimento
Burkholderia/fisiologia
Polissacarídeos Bacterianos/metabolismo
[Mh] Termos MeSH secundário: Burkholderia/química
Espectroscopia de Ressonância Magnética/métodos
Polissacarídeos Bacterianos/química
Espectrometria de Fluorescência/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Polysaccharides, Bacterial)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.785048



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