Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Am Chem Soc ; 145(17): 9840-9849, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37089019

RESUMO

Polysaccharides have been successfully used as immunogens for the development of vaccines against bacterial infection; however, there are no oligosaccharide-based vaccines available to date and no previous studies of their processing and presentation. We reported here the intracellular enzymatic processing and antigen presentation of an oligosaccharide-conjugate cancer vaccine prepared from the glycan of Globo-H (GH), a globo-series glycosphingolipid (GSL). This oligosaccharide-conjugate vaccine was shown to elicit antibodies against the glycan moieties of all three globo-series GSLs that are exclusively expressed on many types of cancer and their stem cells. To understand the specificity and origin of cross-reactivity of the antibodies elicited by the vaccine, we found that the vaccine is first processed by fucosidase 1 in the early endosome of dendritic cells to generate a common glycan antigen of the GSLs along with GH for MHC class II presentation. This work represents the first study of oligosaccharide processing and presentation and is expected to facilitate the design and development of glycoconjugate vaccines based on oligosaccharide antigens.


Assuntos
Vacinas Anticâncer , Neoplasias , Humanos , Vacinas Conjugadas , Apresentação de Antígeno , Anticorpos , Polissacarídeos , Oligossacarídeos
2.
Nanotechnology ; 30(28): 284002, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30913543

RESUMO

Understanding the growth mechanism of heterojunctions in silicon-germanium alloy (Si-Ge) nanowires is helpful for designing adequate physical properties in the material for device applications. We examine the formation of the heterojunction in low Ge-content Si-Ge nanowires by an approach of thermal oxidation, which produces an atomically abrupt interface with an obvious concentration change. Forming heterojunctions in Si-Ge nanowires by this approach involves more complicated reaction routes than direct growth of heterojunction nanowires using the vapor-liquid-solid method. At the beginning of the oxidation process, the AuGeSi eutectic liquid at the nanowire tip significantly etches the Si-Ge alloy nanowires. Selective oxidation of Si results in a change of the relative amount of Ge to Si in the eutectic liquid, which further modulates the solubility of Ge and Si atoms. The compositional variation in the Au-Ge-Si ternary alloy system during the oxidation process accounts for the observed concentration profile in the heterojunction nanowire. The thermal oxidation approach is applied on a low Ge-content Si-Ge thin film that is coated with Au nanoparticles. Si-Ge nanodots, which exhibit a higher Ge concentration, are precipitated epitaxially in the film, as a result of compositional modulation in the AuGeSi eutectic liquid.

3.
Int J Mol Sci ; 20(7)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30987025

RESUMO

BACKGROUND: S1P has been shown to improve the endothelialization of decellularized vascular grafts in vitro. Here, we evaluated the potential of tissue-engineered vascular grafts (TEVGs) constructed by ECs and S1P on decellularized vascular scaffolds in a rat model. METHODS: Rat aorta was decellularized mainly by 0.1% SDS and characterized by histology. Rat ECs, were seeded onto decellularized scaffolds, and the viability of the ECs was evaluated by biochemical assays. Then, we investigated the in vivo patency rate and endothelialization for five groups of decellularized vascular grafts (each n = 6) in a rat abdominal aorta model for 14 days. The five groups included (1) rat allogenic aorta (RAA); (2) decellularized RAA (DRAA); (3) DRAA with S1P (DRAA/S1P); (4) DRAA with EC recellularization (DRAA/EC); and (5) DRAA with S1P and EC recellularization (DRAA/EC/S1P). RESULTS: In vitro, ECs were identified by the uptake of Dil-Ac-LDL. S1P enhanced the expression of syndecan-1 on ECs and supported the proliferation of ECs on decellularized vascular grafts. In vivo, RAA and DRAA/EC/S1P both had 100% patency without thrombus formation within 14 days. Better endothelialization, more wall structure maintenance and less inflammation were noted in the DRAA/EC/S1P group. In contrast, there was thrombus formation in the DRAA, DRAA/S1P and DRAA/EC groups. CONCLUSION: S1P could inhibit thrombus formation to improve the patency rate of EC-covered decellularized vascular grafts in vivo and may play an important role in the construction of TEVGs.


Assuntos
Prótese Vascular , Células Endoteliais/metabolismo , Lisofosfolipídeos/metabolismo , Esfingosina/análogos & derivados , Grau de Desobstrução Vascular , Animais , Aorta/transplante , Implante de Prótese Vascular , Proliferação de Células , Forma Celular , Feminino , Macrófagos/metabolismo , Ratos Sprague-Dawley , Esfingosina/metabolismo , Análise de Sobrevida , Sindecana-1/metabolismo
4.
Bioorg Med Chem Lett ; 28(16): 2682-2687, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29731364

RESUMO

Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide using S-adenosyl-L-methionine (SAM) as a methyl donor and, through doing so, can modulate cellular methylation potential to impact diverse epigenetic processes. NNMT has been implicated in a range of diseases, including cancer and metabolic disorders. Potent, selective, and cell-active inhibitors would constitute valuable probes to study the biological functions and therapeutic potential of NNMT. We previously reported the discovery of electrophilic small molecules that inhibit NNMT by reacting with an active-site cysteine residue in the SAM-binding pocket. Here, we have used activity-based protein profiling (ABPP)-guided medicinal chemistry to optimize the potency and selectivity of NNMT inhibitors, culminating in the discovery of multiple alpha-chloroacetamide (αCA) compounds with sub-µM IC50 values in vitro and excellent proteomic selectivity in cell lysates. However, these compounds showed much weaker inhibition of NNMT in cells, a feature that was not shared by off-targets of the αCAs. Our results show the potential for developing potent and selective covalent inhibitors of NNMT, but also highlight challenges that may be faced in targeting this enzyme in cellular systems.


Assuntos
Acetamidas/farmacologia , Inibidores Enzimáticos/farmacologia , Nicotinamida N-Metiltransferase/antagonistas & inibidores , Acetamidas/síntese química , Domínio Catalítico , Linhagem Celular Tumoral , Cisteína/química , Inibidores Enzimáticos/síntese química , Humanos , Nicotinamida N-Metiltransferase/química
6.
Nano Lett ; 17(12): 7494-7499, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29185770

RESUMO

Compositional abruptness of the interfaces is one of the important factors to determine the performance of Group IV semiconductor heterojunction (Si/Ge or Si/SiGe) nanowire devices. However, forming abrupt interfaces in the nanowires using the common vapor-liquid-solid (VLS) method is restricted because large solubility of Si and Ge in the Au eutectic liquid catalyst makes gradual composition change at the heterojunction after switching the gas phase components. According to the VLS growth mechanism, another possible approach to form an abrupt interface is making a change of the semiconductor concentration in the eutectic liquid before precipitation of the second phase. Here we show that the composition in AuSiGe eutectic liquid on SiGe nanowires of low Ge concentration (≤6%) can be altered by thermal oxidation at 700 °C. During the oxidation process, only Si is oxidized on the surface of the eutectic liquid, and the Ge/Si ratio in the eutectic liquid is increased. The subsequently precipitated SiGe step at the liquid/solid interface has a higher Ge concentration (∼20%), and a compositionally abrupt interface is produced in the nanowires. The growth mechanism of the heterojunction includes diffusion of Si and Ge atoms on nanowire surface into the AuSiGe eutectic liquid and step nucleation at the liquid/nanowire interface.

7.
Proc Natl Acad Sci U S A ; 110(7): 2517-22, 2013 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-23355685

RESUMO

Globo H (GH) is a hexasaccharide specifically overexpressed on a variety of cancer cells and therefore, a good candidate for cancer vaccine development. To identify the optimal carrier and adjuvant combination, we chemically synthesized and linked GH to a carrier protein, including keyhole limpet hemocyanion, diphtheria toxoid cross-reactive material (CRM) 197 (DT), tetanus toxoid, and BSA, and combined with an adjuvant, and it was administered to mice for the study of immune response. Glycan microarray analysis of the antiserum obtained indicated that the combination of GH-DT adjuvanted with the α-galactosylceramide C34 has the highest enhancement of anti-GH IgG. Compared with the phase III clinical trial vaccine, GH-keyhole limpet hemocyanion/QS21, the GH-DT/C34 vaccine elicited more IgG antibodies, which are more selective for GH and the GH-related epitopes, stage-specific embryonic antigen 3 (SSEA3) and SSEA4, all of which were specifically overexpressed on breast cancer cells and breast cancer stem cells with SSEA4 at the highest level (>90%). We, therefore, further developed SSEA4-DT/C34 as a vaccine candidate, and after immunization, it was found that the elicited antibodies are also IgG-dominant and very specific for SSEA4.


Assuntos
Antígenos Glicosídicos Associados a Tumores/farmacologia , Proteínas de Bactérias/imunologia , Neoplasias da Mama/prevenção & controle , Vacinas Anticâncer/química , Antígenos Embrionários Estágio-Específicos/imunologia , Animais , Antígenos Glicosídicos Associados a Tumores/administração & dosagem , Antígenos Glicosídicos Associados a Tumores/química , Antígenos Glicosídicos Associados a Tumores/imunologia , Neoplasias da Mama/imunologia , Feminino , Citometria de Fluxo , Hemocianinas , Soros Imunes/análise , Imunoglobulina G/imunologia , Camundongos , Análise em Microsséries , Estrutura Molecular , Células-Tronco Neoplásicas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Toxoide Tetânico
8.
Eur J Public Health ; 25(6): 1024-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25841034

RESUMO

BACKGROUND: Certain factors originating from the perinatal and childhood periods are suspected of contributing to the recent increasing trend of childhood type 1 diabetes (T1D) incidence. This study sought to investigate the relationships between various perinatal and childhood risk factors and T1D incidence in young children (<10 years). METHODS: We used a nested case-control design based on 1,478,573 live births born in 2000-05 in Taiwan. Cases were 632 incident cases of T1D between 2000 and 2008. Ten matched controls for each case were randomly selected. Information on various perinatal risk factors was also identified from claim data. Multiple conditional logistic regression was employed to estimate odds ratio (OR) and 95 confidence interval (CI) of T1D. RESULTS: Childhood infection was significantly associated with an increased risk of T1D (OR = 1.46, 95% CI = 1.23-1.73). Increased risk of T1D was also noted in children born to younger mothers (<25 years) (OR = 1.94, 95% CI = 1.34-2.81), older fathers (>30 years) (OR = 1.56 (95% CI = 1.16-2.10) to 1.57 (95% CI = 1.19-2.05), mothers with Caesarean section (CS) (OR = 2.35, 95% CI = 1.52-3.64), and mothers with gestational diabetes mellitus (OR = 4.36, 95% CI = 2.76-7.77). Fathers with T1D (OR = 7.36, 95% CI = 1.02-57.21) or type 2 diabetes (OR = 1.54, 95% CI = 1.04-2.26) were observed to substantially increase the risk of offspring T1D. CONCLUSIONS: Certain modifiable perinatal factors such as infection and CS may predispose incidence of T1D in young children.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Peso ao Nascer , Estudos de Casos e Controles , Cesárea/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Infecções/epidemiologia , Modelos Logísticos , Masculino , Idade Materna , Razão de Chances , Idade Paterna , Fatores de Risco , Taiwan
9.
J Am Chem Soc ; 136(48): 16844-53, 2014 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-25371992

RESUMO

Globo H-based therapeutic cancer vaccines have been tested in clinical trials for the treatment of late stage breast, ovarian, and prostate cancers. In this study, we explored Globo H analogue antigens with an attempt to enhance the antigenic properties in vaccine design. The Globo H analogues with modification at the reducing or nonreducing end were synthesized using chemoenzymatic methods, and these modified Globo H antigens were then conjugated with the carrier protein diphtheria toxoid cross-reactive material (CRM) 197 (DT), and combined with a glycolipid C34 as an adjuvant designed to induce a class switch to form the vaccine candidates. After Balb/c mice injection, the immune response was studied by a glycan array and the results showed that modification at the C-6 position of reducing end glucose of Globo H with the fluoro, azido, or phenyl group elicited IgG antibody response to specifically recognize Globo H (GH) and the GH-related epitopes, stage-specific embryonic antigen 3 (SSEA3) (also called Gb5) and stage-specific embryonic antigen 4 (SSEA4). However, only the modification of Globo H with the azido group at the C-6 position of the nonreducing end fucose could elicit a strong IgG immune response. Moreover, the antibodies induced by these vaccines were shown to recognize GH expressing tumor cells (MCF-7) and mediate the complement-dependent cell cytotoxicity against tumor cells. Our data suggest a new potential approach to cancer vaccine development.


Assuntos
Antígenos Glicosídicos Associados a Tumores/química , Antígenos Glicosídicos Associados a Tumores/imunologia , Vacinas Anticâncer/imunologia , Animais , Antígenos Glicosídicos Associados a Tumores/farmacologia , Vacinas Anticâncer/química , Vacinas Anticâncer/farmacologia , Configuração de Carboidratos , Proliferação de Células/efeitos dos fármacos , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Oxirredução , Relação Estrutura-Atividade
10.
Int J Antimicrob Agents ; 63(2): 107067, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38141835

RESUMO

OBJECTIVES: To investigate the prevalence of polypharmacy and potential drug-drug interactions (DDIs), and the factors associated with DDIs among people living with human immunodeficiency virus (HIV; PLWH) in the modern era of antiretroviral therapy (ART). METHODS: This cross-sectional study included PLWH who had been on ART for ≥3 months at two designated HIV hospitals in Taiwan. All ART and non-ART prescriptions were collected from the NHI-MediCloud System and screened for DDIs using the University of Liverpool HIV drug interactions database. A case-control analysis was conducted to investigate the factors associated with DDIs. RESULTS: In total, 1007 PLWH were included in this study from June 2021 to August 2022. The median age was 40 (interquartile range 33-49) years, and 96.2% were taking integrase strand transfer inhibitor (INSTI)-based ART. The proportions of PLWH with at least one non-communicable disease and polypharmacy were 50.0% and 18.7%, respectively. Seven (0.7%) PLWH had red-flagged DDIs, and 159 (15.8%) had amber-flagged DDIs. In multi-variable models, the prevalence of DDIs was associated with older age [adjusted odds ratio (aOR) per 1-year increase 1.022), number of co-medications (aOR 1.097), use of boosted INSTI-based ART (vs unboosted INSTI, aOR 8.653), and concomitant medications in the alimentary tract and metabolism category (aOR 11.058) and anti-neoplastic and immunomodulating agents (aOR 14.733). CONCLUSIONS: In the INSTI era, the prevalence of potential DDIs is lower than noted previously, but remains substantial. Clinicians should monitor DDIs routinely, especially in older PLWH, those taking a higher number of co-medications, and those who are taking booster-containing ART or medications from specific categories.


Assuntos
Infecções por HIV , HIV , Humanos , Idoso , Adulto , Pessoa de Meia-Idade , Polimedicação , Estudos Transversais , Infecções por HIV/complicações , Interações Medicamentosas , Integrases
11.
J Am Chem Soc ; 135(39): 14831-9, 2013 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-24044869

RESUMO

We report here the development of chemoenzymatic methods for the large-scale synthesis of cancer-associated antigens globopentaose (Gb5), fucosyl-Gb5 (Globo H), and sialyl-Gb5 (SSEA4) by using overexpressed glycosyltransferases coupled with effective regeneration of sugar nucleotides, including UDP-Gal, UDP-GalNAc, GDP-Fuc, and CMP-Neu5Ac. The enzymes used in the synthesis were first identified from different species through comparative studies and then overexpressed in E. coli and isolated for synthesis. These methods provide multigram quantities of products in high yield with only two or three purification steps and are suitable for the evaluation and development of cancer vaccines and therapeutics.


Assuntos
Antígenos Glicosídicos Associados a Tumores/metabolismo , Escherichia coli/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Antígenos Glicosídicos Associados a Tumores/química , Clonagem Molecular , Glicosiltransferases/isolamento & purificação , Microbiologia Industrial , Regulação para Cima
12.
Hum Vaccin Immunother ; 19(1): 2171231, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36919452

RESUMO

Guillain-Barré syndrome (GBS) is a rare but severe complication of COVID-19 vaccination. We report two cases of GBS following vaccination with the adenovirus vector vaccine ChAdOx1 nCoV-19 (Vaxzevria, AstraZeneca) and review the relevant literature. Relevant studies published between December 2020 and May 2022 including 881 patients with GBS were reviewed. GBS incidence and the need for mechanical ventilation were reported at a higher level among patients receiving Vaxzevria (n = 400). However, incidence cannot be accurately estimated from case reports. Thus, the true GBS rates following COVID-19 vaccination should be determined by population-based data.


Assuntos
COVID-19 , Síndrome de Guillain-Barré , Vacinas contra Influenza , Humanos , Síndrome de Guillain-Barré/etiologia , Síndrome de Guillain-Barré/epidemiologia , Vacinas contra COVID-19/efeitos adversos , ChAdOx1 nCoV-19 , COVID-19/prevenção & controle , COVID-19/complicações , Vacinação/efeitos adversos
13.
J Biomed Sci ; 19: 63, 2012 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-22776023

RESUMO

BACKGROUND: Dysmorphogenesis and multiple organ defects are well known in zebrafish (Danio rerio) embryos with T-box transcription factor 5 (tbx5) deficiencies, mimicking human Holt-Oram syndrome. METHODS: Using an oligonucleotide-based microarray analysis to study the expression of special genes in tbx5 morphants, we demonstrated that GH and some GH-related genes were markedly downregulated. Zebrafish embryos microinjected with tbx5-morpholino (MO) antisense RNA and mismatched antisense RNA in the 1-cell stage served as controls, while zebrafish embryos co-injected with exogenous growth hormone (GH) concomitant with tbx5-MO comprised the treatment group. RESULTS: The attenuating effects of GH in tbx5-MO knockdown embryos were quantified and observed at 24, 30, 48, 72, and 96 h post-fertilization. Though the understanding of mechanisms involving GH in the tbx5 functioning complex is limited, exogenous GH supplied to tbx5 knockdown zebrafish embryos is able to enhance the expression of downstream mediators in the GH and insulin-like growth factor (IGF)-1 pathway, including igf1, ghra, and ghrb, and signal transductors (erk1, akt2), and eventually to correct dysmorphogenesis in various organs including the heart and pectoral fins. Supplementary GH also reduced apoptosis as determined by a TUNEL assay and decreased the expression of apoptosis-related genes and proteins (bcl2 and bad) according to semiquantitative reverse-transcription polymerase chain reaction and immunohistochemical analysis, respectively, as well as improving cell cycle-related genes (p27 and cdk2) and cardiomyogenetic genes (amhc, vmhc, and cmlc2). CONCLUSIONS: Based on our results, tbx5 knockdown causes a pseudo GH deficiency in zebrafish during early embryonic stages, and supplementation of exogenous GH can partially restore dysmorphogenesis, apoptosis, cell growth inhibition, and abnormal cardiomyogenesis in tbx5 knockdown zebrafish in a paracrine manner.


Assuntos
Desenvolvimento Embrionário , Hormônio do Crescimento , Morfogênese , Proteínas com Domínio T , Peixe-Zebra , Anormalidades Múltiplas , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/genética , Hormônio do Crescimento/metabolismo , Coração/efeitos dos fármacos , Coração/crescimento & desenvolvimento , Cardiopatias Congênitas , Comunicação Interatrial , Humanos , Deformidades Congênitas das Extremidades Inferiores , Morfogênese/efeitos dos fármacos , Morfogênese/genética , Morfolinos , Comunicação Parácrina , RNA Antissenso/administração & dosagem , Somatomedinas/genética , Somatomedinas/metabolismo , Proteínas com Domínio T/deficiência , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Deformidades Congênitas das Extremidades Superiores , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
14.
PLoS One ; 17(3): e0264946, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35303001

RESUMO

INTRODUCTION: Although infection was the most common symptom in patients returning to the ED, whether intravenous antibiotic administration at the index visit could serve as an indicator of patients with infectious diseases at high risk for hospital admission after returning to the ED within a short period of time remains unclear. The study aimed to investigate the potential risk factors for hospital admission in patients returning to the ED within 72 hours with a final diagnosis of infectious diseases. MATERIAL AND METHODS: This retrospective cohort study analyzed return visits to the ED from January to December 2019. Adult patients aged >20 years who had a return visit to the ED within 72 hours with an infectious disease were included herein. In total, 715 eligible patients were classified into the intravenous antibiotics and non-intravenous antibiotics group (reference group). The outcome studied was hospital admission to general ward and intensive care unit (ICU) at the return visits. RESULTS: Patients receiving intravenous antibiotics at index visits had significantly higher risk-approximately two times-for hospital admission at the return visits than those did not (adjusted odds ratio = 2.47, 95% CI = 1.34-4.57, p = 0.004). For every 10 years increase in age, the likelihood for hospital admission increased by 38%. Other factors included abnormal respiratory rate and high C-reactive protein levels. CONCLUSIONS: Intravenous antibiotic administration at the index visit was an independent risk factor for hospital admission at return visits in patients with an infection disease. Physicians should consider carefully before discharging patients receiving intravenous antibiotics.


Assuntos
Doenças Transmissíveis , Readmissão do Paciente , Adulto , Antibacterianos/uso terapêutico , Serviço Hospitalar de Emergência , Hospitais , Humanos , Estudos Retrospectivos , Fatores de Risco
15.
J Am Chem Soc ; 132(38): 13371-80, 2010 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-20822102

RESUMO

A new type of glycan array covalently or noncovalently attached to aluminum oxide-coated glass (ACG) slides has been developed for studies of enzymatic reactions and protein binding. To prepare the noncovalent array, glycans with a polyfluorinated hydrocarbon (-C(8)F(17)) tail are spotted robotically onto the ACG slide surface containing a layer of polyfluorinated hydrocarbon terminated with phosphonate. After incubation and washing, the noncovalent array can be characterized by MS-TOF via ionization/desorption at a low laser energy without addition of matrix. A representative cellotetraose array was developed to study the activity and specificity of different cellulases and to differentiate the exo- and endoglucanase activities. To prepare the covalent array, glycans with a phosphonic acid tail were synthesized and spotted robotically onto the ACG slide surface. After incubation, the slides can be used directly for quantitative protein binding analysis. Compared to the preparation of glycan arrays on glass slides and other surfaces, this method of arraying using phosphonic acid reacting with ACG is more direct, convenient, and effective and represents a new platform for the high-throughput analysis of protein-glycan interactions.


Assuntos
Óxido de Alumínio/química , Vidro , Organofosfonatos/química , Polissacarídeos/química , Celulase/química , Espectrometria de Massas
16.
Healthcare (Basel) ; 8(4)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321949

RESUMO

Coronavirus disease 2019 (COVID-19) has caused a global pandemic and exerted a profound physiological and mental impact on the public. Due to anxiety from being bombarded by information from the news and social media, people may constantly read and repost, with a fear of missing out (FOMO), information about COVID-19 on social media. So far, there has been little research on COVID-19 FOMO. We therefore compiled the COVID-19 information fear of missing out scale (CIFS) and administered it to 1178 adults in Taiwan to identify the possible factors influencing CIFS scores. We demonstrated that the CIFS had good reliability, factor validity, and criterion validity. With regard to demographic variables, we found that gender, marital status, travel time to the nearest hospital, and educational background influenced CIFS scores. In contrast, the participant age and whether he or she lived in an urban area did not affect the CIFS scores. With regard to social media usage, social media usage time (r = 0.025) and the numbers of COVID-19-related posts read on social media (r = 0.117) or instant messaging (r = 0.169) were not highly correlated with CIFS scores. Rather, CIFS scores were found to be significantly correlated to the frequency of reposting COVID-19-related information on social media (r = 0.497) and on instant messaging (r = 0.447). These results indicate that CIFS scores are closely associated not with passive browsing on social media but with the frequency at which an individual actively reposts information. In other words, what creates CIF is not an overabundance of information (i.e., an infodemic) but the active reposting and interpretation of information. Individual autonomy for interpretation of the received information and self-determination about reposting are key factors for COVID-19 information FOMO. When facing the COVID-19-related news on social media, it is the active information-related FOMO, not the passive infodemic, that influences our social media usage.

17.
Nat Chem ; 11(12): 1113-1123, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659311

RESUMO

A fundamental challenge in chemical biology and medicine is to understand and expand the fraction of the human proteome that can be targeted by small molecules. We recently described a strategy that integrates fragment-based ligand discovery with chemical proteomics to furnish global portraits of reversible small-molecule/protein interactions in human cells. Excavating clear structure-activity relationships from these 'ligandability' maps, however, was confounded by the distinct physicochemical properties and corresponding overall protein-binding potential of individual fragments. Here, we describe a compelling solution to this problem by introducing a next-generation set of fully functionalized fragments differing only in absolute stereochemistry. Using these enantiomeric probe pairs, or 'enantioprobes', we identify numerous stereoselective protein-fragment interactions in cells and show that these interactions occur at functional sites on proteins from diverse classes. Our findings thus indicate that incorporating chirality into fully functionalized fragment libraries provides a robust and streamlined method to discover ligandable proteins in cells.


Assuntos
Sondas Moleculares/química , Proteínas/química , Proteoma/química , Bibliotecas de Moléculas Pequenas/química , Humanos , Ligantes , Estrutura Molecular , Estereoisomerismo
18.
Oncogene ; 38(28): 5580-5598, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31152147

RESUMO

Gram-negative bacteria have been found to be a major population in prostatitis and prostate cancer (PCa) tissues. Lipopolysaccharide (LPS), a major compound of Gram-negative bacteria, with stimulatory activities in some cancer types, but has not been fully studied in PCa. In this study, we examined the effect of LPS on the invasion of PCa cells. Interestingly, LPS can enhance the invasiveness of PCa, but had no significant effect on PCa cell viability. Using protease inhibitor screening and biochemical analyses, matriptase, a member of the membrane-anchored serine protease family, is found to play a key role in LPS-induced PCa cell invasion. Mechanistically, Toll-like receptor 4 (TLR4, LPS receptor)-sphingosine kinase 1 (SphK1) signaling underlies LPS-induced matriptase activation and PCa cell invasion. Specifically, LPS induced the S225 phosphorylation of SphK1 and the translocation of SphK1 to plasma membrane, leading to the production of sphingosine 1-phosphate (S1P), ERK1/2 and matriptase activation via S1P receptor 4 (S1PR4). This phenomenon is further validated using the patient-derived explant (PDE) model. Indeed, there is a significant correlation among the elevated SphK1 levels, the Gleason grades of PCa specimens, and the poor survival of PCa patients. Taken together, this study demonstrates a potential impact of LPS on PCa progression. Our results provide not only a new finding of the role of bacterial infection in PCa progression but also potential therapeutic target(s) associated with PCa metastasis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Polissacarídeos/farmacologia , Neoplasias da Próstata/patologia , Serina Endopeptidases/metabolismo , Receptores de Esfingosina-1-Fosfato/metabolismo , Progressão da Doença , Ativação Enzimática , Humanos , Masculino , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/metabolismo
19.
J Chin Med Assoc ; 69(4): 146-52, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16689194

RESUMO

BACKGROUND: Many reports in the literature suggest that chronic hepatitis C virus (HCV) infection is associated with diabetes, but the results are conflicting. The aim of our study was to investigate the seroprevalence of hepatitis B virus (HBV) and HCV infections in type 2 diabetes mellitus (DM) patients. METHODS: We collected 820 consecutive type 2 diabetic patients attending 2 of 5 outpatient endocrinology clinics in Far Eastern Memorial Hospital from March to July 2003. The control group consisted of 905 subjects who came for medical check-ups at the Family Medicine Department. We determined hepatitis B surface antigen (HBsAg) and anti-HCV in both groups, using third-generation microparticle enzyme immunoassay. RESULTS: No significant difference was found between type 2 DM patients and the control group for seropositivity of HBsAg (13.5% versus 12.4%; odds ratio [OR] = 1.09; 95% confidence interval [CI]: 0.77-1.55; p = 0.441), but anti-HCV seropositivity was detected in 6.8% of patients and 2.6% of the control subjects (OR = 2.87; 95% CI: 1.51-5.46; p < 0.001). In anti-HCV-positive DM patients, abnormal alanine aminotransferase was observed in 61.8%, compared with only 34.2% of anti-HCV-negative DM patients (p < 0.001). We did not observe any difference in risk factors for HCV infection between anti-HCV-positive and -negative DM patients. CONCLUSION: The rate of seropositive anti-HCV is 2.8 times higher in type 2 DM patients than non-diabetic control subjects.


Assuntos
Diabetes Mellitus Tipo 2/virologia , Anticorpos Anti-Hepatite B/sangue , Anticorpos Anti-Hepatite C/sangue , Adulto , Idoso , Alanina Transaminase/sangue , Índice de Massa Corporal , Estudos Transversais , Feminino , Antígenos de Superfície da Hepatite B/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos
20.
Oncogene ; 23(1): 122-9, 2004 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-14712217

RESUMO

The lipid growth factor lysophosphatidic acid (LPA) is produced by ovarian cancer cells in quantities sufficient to attain concentrations of up to 10 microM. An autocrine circuit was demonstrated when ovarian cancer cells, but not normal ovarian surface epithelial cells, were proven to express LPA(2) (Edg-4) and LPA(3) (Edg-7) G protein-coupled receptors for LPA. Human LPA(2) now has been expressed transgenically in C57BL/6 mouse ovaries under direction of the alpha-inhibin large promoter. Human LPA(2) mRNA and protein were detected in all transgenic (TG) mouse ovaries at levels far higher than in other tissues and at least fivefold higher than in cultured lines of human ovarian cancer cells, with the expected sex cord-stromal distribution. Most LPA(2) TG ovaries produced significantly higher levels than non-TG ovaries of type A, but not type B, vascular endothelial growth factor (VEGF), isomers of VEGF-A, and urokinase-type plasminogen activator (uPA). Many LPA(2) TG ovaries had elevated expression of VEGF receptors 1 and 2, and a depressed level of type 2 PA inhibitor. Thus, the LPA-LPA(2) circuit regulates ovarian cells both directly and through increases in protein growth factor systems.


Assuntos
Lisofosfolipídeos/biossíntese , Ovário/metabolismo , Receptores Acoplados a Proteínas G/biossíntese , Animais , Feminino , Lisofosfolipídeos/análise , Lisofosfolipídeos/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Inibidor 2 de Ativador de Plasminogênio/análise , RNA Mensageiro/análise , Receptores Acoplados a Proteínas G/análise , Receptores Acoplados a Proteínas G/genética , Ativador de Plasminogênio Tipo Uroquinase/análise , Fator A de Crescimento do Endotélio Vascular/análise , Fator B de Crescimento do Endotélio Vascular/análise , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/análise , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA