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1.
Int J Biol Macromol ; 267(Pt 1): 131201, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554921

RESUMO

As a promising green and sustainable coating material, gum was extracted from durian seed to produce eutectogel, which the properties were tunable using natural deep eutectic solvent (NADES). Ten different eutectogels were successfully synthesized using durian seed gum (DSG) and xanthan gum (XG) gelators at different composition (5, 10, 15 %) to gel choline chloride-glucose (1:1), choline chloride-fructose (1:2) and betaine-glucose-water (1:1:1) NADESs. Results revealed that eutectogel was non-Newtonian and weak gel material with excellent thermostability up to 200 °C. When the gum content increased, the resulted eutectogel showed higher viscosity, yield stress, hardness, gumminess, adhesiveness, and weight holding capacity. In overall, choline chloride-fructose (1:2) NADES and 10 % of DSG formed an excellent eutectogel which remained stable and compatible upon 12 weeks of storage. It displayed superior viscoelastic, texture, gases and moisture barrier properties which were beneficial for food coating application. This eutectogel was able to extend the shelf life of fresh-cut apples during storage with lower weight loss and higher total phenolic content (TPC). The potential future of this well-characterized tunable DSG-derived eutectogel includes, but not limited to, food and pharmaceutical industries, smart sensing, flexible wearable electronics, water purification, supercapacitors and batteries.


Assuntos
Bombacaceae , Conservação de Alimentos , Géis , Gomas Vegetais , Reologia , Sementes , Gomas Vegetais/química , Sementes/química , Géis/química , Bombacaceae/química , Conservação de Alimentos/métodos , Viscosidade , Polissacarídeos Bacterianos/química , Temperatura
3.
Elife ; 4: e07735, 2015 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-26287480

RESUMO

Actin filaments assemble inside the nucleus in response to multiple cellular perturbations, including heat shock, protein misfolding, integrin engagement, and serum stimulation. We find that DNA damage also generates nuclear actin filaments-detectable by phalloidin and live-cell actin probes-with three characteristic morphologies: (i) long, nucleoplasmic filaments; (ii) short, nucleolus-associated filaments; and (iii) dense, nucleoplasmic clusters. This DNA damage-induced nuclear actin assembly requires two biologically and physically linked nucleation factors: Formin-2 and Spire-1/Spire-2. Formin-2 accumulates in the nucleus after DNA damage, and depletion of either Formin-2 or actin's nuclear import factor, importin-9, increases the number of DNA double-strand breaks (DSBs), linking nuclear actin filaments to efficient DSB clearance. Nuclear actin filaments are also required for nuclear oxidation induced by acute genotoxic stress. Our results reveal a previously unknown role for nuclear actin filaments in DNA repair and identify the molecular mechanisms creating these nuclear filaments.


Assuntos
Citoesqueleto de Actina/metabolismo , Dano ao DNA , Reparo do DNA , Proteínas dos Microfilamentos/metabolismo , Proteínas Nucleares/metabolismo , Multimerização Proteica , Linhagem Celular , Núcleo Celular/metabolismo , Forminas , Humanos
4.
PLoS Pathog ; 10(3): e1003961, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24604090

RESUMO

The Herpes Simplex Virus 1 (HSV-1) glycoprotein gE-gI is a transmembrane Fc receptor found on the surface of infected cells and virions that binds human immunoglobulin G (hIgG). gE-gI can also participate in antibody bipolar bridging (ABB), a process by which the antigen-binding fragments (Fabs) of the IgG bind a viral antigen while the Fc binds to gE-gI. IgG Fc binds gE-gI at basic, but not acidic, pH, suggesting that IgG bound at extracellular pH by cell surface gE-gI would dissociate and be degraded in acidic endosomes/lysosomes if endocytosed. The fate of viral antigens associated with gE-gI-bound IgG had been unknown: they could remain at the cell surface or be endocytosed with IgG. Here, we developed an in vitro model system for ABB and investigated the trafficking of ABB complexes using 4-D confocal fluorescence imaging of ABB complexes with transferrin or epidermal growth factor, well-characterized intracellular trafficking markers. Our data showed that cells expressing gE-gI and the viral antigen HSV-1 gD endocytosed anti-gD IgG and gD in a gE-gI-dependent process, resulting in lysosomal localization. These results suggest that gE-gI can mediate clearance of infected cell surfaces of anti-viral host IgG and viral antigens to evade IgG-mediated responses, representing a general mechanism for viral Fc receptors in immune evasion and viral pathogenesis.


Assuntos
Antígenos Virais/imunologia , Herpes Simples/imunologia , Evasão da Resposta Imune/imunologia , Receptores Fc/imunologia , Proteínas Virais/imunologia , Membrana Celular/imunologia , Imunofluorescência , Células HeLa , Herpesvirus Humano 1/imunologia , Humanos , Microscopia Confocal , Transfecção
5.
J Anal Methods Chem ; 2014: 271970, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24563804

RESUMO

Fourier Transform Infrared (FTIR) and Gas Chromatography Mass Spectrometry (GCMS) are two common instruments used for analysis of edible oils. The output signal is often analysed on the software attached to the workstations. The processing software is usually individualised for a specific source. The output of GCMS cannot be analysed on the FTIR hence analysts often need to juggle between instruments when multiple techniques are employed. This could become exhaustive when a large dataset is involved. This paper reports a synchronised approach for analysis of signal from FTIR and GCMS. The algorithm is demonstrated on a dataset of edible oils to investigate the thermal degradation of seven types of edible oils treated at 100°C and 150°C. The synchronised routines identify peaks present in FTIR and GCMS spectra/chromatograms where the information is subsequently extracted onto peak tables for further analysis. In this study, it is found that palm based products and corn oils were relatively more stable with higher content of antioxidants tocopherols and squalene. As a conclusion, this approach allows simultaneous analysis of signal from multiple sources and samples enhancing the efficiency of the signal processing process.

6.
Int Sch Res Notices ; 2014: 870187, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-27437493

RESUMO

This paper reports the metals content in water, sediment, macroalgae, aquatic plant, and fish of Batang Ai Hydroelectric Reservoir in Sarawak, Malaysia. The samples were acid digested and subjected to atomic absorption spectrometry analysis for Na, K, Mn, Cr, Ni, Zn, Mg, Fe, Sn, Al, Ca, As, Se, and Hg. The total Hg content was analysed on the mercury analyser. Results showed that metals in water, sediment, macroalgae, aquatic plant, and fish are distinguishable, with sediment and biota samples more susceptible to metal accumulation. The distributions of heavy metals in water specifically Se, Sn, and As could have associated with the input of fish feed, boating, and construction activities. The accumulation of heavy metals in sediment, macroalgae, and aquatic plant on the other hand might be largely influenced by the redox conditions in the aquatic environment. According to the contamination factor and the geoaccumulation index, sediment in Batang Ai Reservoir possesses low risk of contamination. The average metal contents in sediment and river water are consistently lower than the literature values reported and well below the limit of various guidelines. For fishes, trace element Hg was detected; however, the concentration was below the permissible level suggested by the Food and Agriculture Organization.

7.
J Exp Med ; 210(6): 1235-49, 2013 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-23712429

RESUMO

Recently identified broadly neutralizing antibodies (bNAbs) that potently neutralize most HIV-1 strains are key to potential antibody-based therapeutic approaches to combat HIV/AIDS in the absence of an effective vaccine. Increasing bNAb potencies and resistance to common routes of HIV-1 escape through mutation would facilitate their use as therapeutics. We previously used structure-based design to create the bNAb NIH45-46(G54W), which exhibits superior potency and/or breadth compared with other bNAbs. We report new, more effective NIH45-46(G54W) variants designed using analyses of the NIH45-46-gp120 complex structure and sequences of NIH45-46(G54W)-resistant HIV-1 strains. One variant, 45-46m2, neutralizes 96% of HIV-1 strains in a cross-clade panel and viruses isolated from an HIV-infected individual that are resistant to all other known bNAbs, making it the single most broad and potent anti-HIV-1 antibody to date. A description of its mechanism is presented based on a 45-46m2-gp120 crystal structure. A second variant, 45-46m7, designed to thwart HIV-1 resistance to NIH45-46(G54W) arising from mutations in a gp120 consensus sequence, targets a common route of HIV-1 escape. In combination, 45-46m2 and 45-46m7 reduce the possible routes for the evolution of fit viral escape mutants in HIV-1YU-2-infected humanized mice, with viremic control exhibited when a third antibody, 10-1074, was added to the combination.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/genética , Linhagem Celular , Células HEK293 , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/genética , HIV-1/genética , Humanos , Camundongos , Mutação/genética , Mutação/imunologia , Relação Estrutura-Atividade
8.
Proc Natl Acad Sci U S A ; 110(15): 6049-54, 2013 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-23524883

RESUMO

Efforts to design an effective antibody-based vaccine against HIV-1 would benefit from understanding how germ-line B-cell receptors (BCRs) recognize the HIV-1 gp120/gp41 envelope spike. Potent VRC01-like (PVL) HIV-1 antibodies derived from the VH1-2*02 germ-line allele target the conserved CD4 binding site on gp120. A bottleneck for design of immunogens capable of eliciting PVL antibodies is that VH1-2*02 germ-line BCR interactions with gp120 are uncharacterized. Here, we report the structure of a VH1-2*02 germ-line antibody alone and a germ-line heavy-chain/mature light-chain chimeric antibody complexed with HIV-1 gp120. VH1-2*02 residues make extensive contacts with the gp120 outer domain, including all PVL signature and CD4 mimicry interactions, but not critical CDRH3 contacts with the gp120 inner domain and bridging sheet that are responsible for the improved potency of NIH45-46 over closely related clonal variants, such as VRC01. Our results provide insight into initial recognition of HIV-1 by VH1-2*02 germ-line BCRs and may facilitate the design of immunogens tailored to engage and stimulate broad and potent CD4 binding site antibodies.


Assuntos
Anticorpos Neutralizantes/química , Anticorpos Anti-HIV/química , Proteína gp120 do Envelope de HIV/química , Receptores de Antígenos de Linfócitos B/química , Alelos , Sequência de Aminoácidos , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Sítios de Ligação de Anticorpos/imunologia , Linfócitos T CD4-Positivos/citologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Anticorpos Anti-HIV/imunologia , HIV-1 , Humanos , Fragmentos de Imunoglobulinas/química , Fragmentos de Imunoglobulinas/imunologia , Imunoglobulina G/química , Imunoglobulina G/imunologia , Dados de Sequência Molecular , Mutação , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Ressonância de Plasmônio de Superfície
9.
Am J Infect Control ; 40(4): 296-303, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22541852

RESUMO

Professional competency has traditionally been divided into 2 essential components: knowledge and skill. More recent definitions have recommended additional components such as communication, values, reasoning, and teamwork. A standard, widely accepted, comprehensive definition remains an elusive goal. For infection preventionists (IPs), the requisite elements of competence are most often embedded in the IP position description, which may or may not reference national standards or guidelines. For this reason, there is widespread variation among these elements and the criteria they include. As the demand for IP expertise continues to rapidly expand, the Association for Professionals in Infection Control and Epidemiology, Inc, made a strategic commitment to develop a conceptual model of IP competency that could be applicable in all practice settings. The model was designed to be used in combination with organizational training and evaluation tools already in place. Ideally, the Association for Professionals in Infection Control and Epidemiology, Inc, model will complement similar competency efforts undertaken in non-US countries and/or international organizations. This conceptual model not only describes successful IP practice as it is today but is also meant to be forward thinking by emphasizing those areas that will be especially critical in the next 3 to 5 years. The paper also references a skill assessment resource developed by Community and Hospital Infection Control Association (CHICA)-Canada and a competency model developed by the Infection Prevention Society (IPS), which offer additional support of infection prevention as a global patient safety mission.


Assuntos
Infecção Hospitalar/prevenção & controle , Controle de Infecções/métodos , Controle de Infecções/normas , Competência Profissional/normas , Humanos
10.
J Geriatr Psychiatry Neurol ; 22(1): 62-70, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19196632

RESUMO

The Mini-Mental State Examination is a widely used cognitive screening measure. The purpose of the present study was to assess how 5 specific clusters of Mini-Mental State Examination items (ie, subscores) correlate with and predict specific areas of daily functioning in dementia patients, 61 patients with varied forms of dementia were administered the Mini-Mental State Examination and an observation-based daily functional test (the Direct Assessment of Functional Status). The results revealed that the orientation and attention subscores of the Mini-Mental State Examination correlated most significantly with most functional domains. The Mini-Mental State Examination language items correlated with all but the shopping and time orientation tasks, while the Mini-Mental State Examination recall items correlated with the Direct Assessment of Functional Status time orientation and shopping tasks. Stepwise regression analyses found that among the Mini-Mental State Examination subscores, orientation was the single, best independent predictor of daily functioning.


Assuntos
Atividades Cotidianas/psicologia , Demência/psicologia , Avaliação Geriátrica/métodos , Testes Neuropsicológicos/estatística & dados numéricos , Idoso , Atenção , Cognição , Feminino , Avaliação Geriátrica/estatística & dados numéricos , Humanos , Idioma , Masculino , Memória , Rememoração Mental , Orientação , Valor Preditivo dos Testes , Análise e Desempenho de Tarefas
11.
Neurocase ; 15(1): 53-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19085559

RESUMO

Clinical characteristics of autosomal dominant Alzheimer's disease often differ clinically from sporadic disease with the onset of seizures, spasticity and myoclonus early in the disease course. Similarly imaging characteristics may also differ. We report the findings of relative hyperperfusion by Tc-99m HMPAO SPECT in the medial orbitofrontal cortex and anterior temporal lobe in four affected family members carrying a presenilin 1 mutation. SPECT of the four individuals was compared to an age-matched normal database. We speculate that the findings of relative medial orbitofrontal and anterior temporal lobe hyperperfusion may be a marker of early onset Alzheimer's disease in this family.


Assuntos
Encéfalo/diagnóstico por imagem , Mutação de Sentido Incorreto , Presenilina-1/genética , Adulto , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Linhagem , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único
12.
Neurosci Lett ; 398(3): 251-2, 2006 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-16469444

RESUMO

We report a presenilin-1 mutation (T245P) in a Japanese-American family with autosomal dominant Alzheimer's disease with an onset age in the early 40s. The early clinical features were remarkable for their purely amnestic nature. The position of the mutation is in the transmembrane domain that harbors the aspartic acid residue which is believed to be part of the active site of gamma-secretase.


Assuntos
Doença de Alzheimer/genética , Proteínas de Membrana/genética , Adulto , Idade de Início , Amnésia/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Presenilina-1 , Estrutura Terciária de Proteína
13.
Mol Pharmacol ; 67(6): 2102-14, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15788742

RESUMO

Gqalpha family members (Gqalpha, G11alpha, G14alpha, and G15/16alpha) stimulate phospholipase Cbeta (PLCbeta) and inositol lipid signaling but differ markedly in amino acid sequence and tissue distribution predicting unappreciated functional diversity. To examine functional differences, we compared the signaling properties of Gqalpha, G14alpha, and G15alpha and their cellular responses in vascular smooth muscle cells (VSMC). Constitutively active forms of Gqalpha, G14alpha, or G15alpha elicit markedly different responses when introduced to VSMC. Whereas each Galpha stimulated PLCbeta to similar extents when expressed at equal protein levels, Gqalpha and G14alpha but not G15alpha initiated profound cell death within 48 h. This response was the result of activation of apoptotic pathways, because Gqalpha and G14alpha, but not G15alpha, stimulated caspase-3 activation and did not alter phospho-Akt, a regulator of cell survival pathways. Gqalpha and G14alpha stimulate nuclear factor of activated T cell (NFAT) activation in VSMC, but Galpha-induced cell death seems independent of PKC, InsP(3)/Ca(2+), and NFAT, in that pharmacological inhibitors of these pathways did not block cell death. Gene expression analysis indicates that Gqalpha, G14alpha, and G15alpha each elicit markedly different profiles of altered gene sets in VSMC after 24 h. Whereas all three Galpha stimulated changes (> or =2-fold) in 50 shared mRNA, Gqalpha and G14alpha (but not G15alpha) stimulated changes in 221 shared mRNA, many of which are reported to be pro-apoptotic and/or involved with TNF-alpha signaling. We were surprised to find that each Galpha also stimulated changes in nonoverlapping Galpha-specific gene sets. These findings demonstrate that Gqalpha family members activate both overlapping and distinct signaling pathways and are more functionally diverse than previously thought.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/biossíntese , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Perfilação da Expressão Gênica/métodos , Músculo Liso Vascular/metabolismo , Tioléster Hidrolases/biossíntese , Tioléster Hidrolases/genética , Animais , Linhagem Celular , Sobrevivência Celular/fisiologia , Subunidades alfa de Proteínas de Ligação ao GTP/biossíntese , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica/fisiologia , Ratos
14.
FEBS Lett ; 576(3): 325-30, 2004 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-15498556

RESUMO

Severe acute respiratory syndrome associated coronavirus main protease (SARS-CoV Mpro) has been proposed as a prime target for anti-SARS drug development. We have cloned and overexpressed the SARS-CoV Mpro in Escherichia coli, and purified the recombinant Mpro to homogeneity. The kinetic parameters of the recombinant SARS-CoV Mpro were characterized by high performance liquid chromatography-based assay and continuous fluorescence-based assay. Two novel small molecule inhibitors of the SARS-CoV Mpro were identified by high-throughput screening using an internally quenched fluorogenic substrate. The identified inhibitors have Ki values at low microM range with comparable anti-SARS-CoV activity in cell-based assays.


Assuntos
Endopeptidases/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/enzimologia , Proteínas Virais/metabolismo , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Proteases 3C de Coronavírus , Cisteína Endopeptidases , Primers do DNA , Escherichia coli/enzimologia , Escherichia coli/genética , Cinética , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/metabolismo , Espectrometria de Fluorescência/métodos , Proteínas Virais/antagonistas & inibidores
15.
Chem Biol ; 11(9): 1293-9, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15380189

RESUMO

The severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infected more than 8,000 people across 29 countries and caused more than 900 fatalities. Based on the concept of chemical genetics, we screened 50,240 structurally diverse small molecules from which we identified 104 compounds with anti-SARS-CoV activity. Of these 104 compounds, 2 target the SARS-CoV main protease (M(pro)), 7 target helicase (Hel), and 18 target spike (S) protein-angiotensin-converting enzyme 2 (ACE2)-mediated viral entry. The EC(50) of the majority of the 104 compounds determined by SARS-CoV plaque reduction assay were found to be at low micromolar range. Three selected compounds, MP576, HE602, and VE607, validated to be inhibitors of SARS-CoV M(pro), Hel, and viral entry, respectively, exhibited potent antiviral activity (EC(50) < 10 microM) and comparable inhibitory activities in target-specific in vitro assays.


Assuntos
Antivirais/química , Antivirais/farmacologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Enzima de Conversão de Angiotensina 2 , Animais , Antivirais/síntese química , Carboxipeptidases/antagonistas & inibidores , Carboxipeptidases/metabolismo , Chlorocebus aethiops , Técnicas de Química Combinatória , Modelos Moleculares , Estrutura Molecular , Peptidil Dipeptidase A , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/crescimento & desenvolvimento , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Células Vero , Proteínas da Matriz Viral/antagonistas & inibidores , Proteínas da Matriz Viral/metabolismo , Replicação Viral/efeitos dos fármacos
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