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1.
Curr Microbiol ; 81(9): 269, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39003672

RESUMO

The escalation of antimicrobial resistance (AMR) due to the excessive and inappropriate use of antimicrobials has prompted the urgent need for more rapid and effective antimicrobial susceptibility testing (AST) methods. Conventional AST techniques often take 16-24 h, leading to empirical prescription practices and the potential emergence of AMR. The study aimed to develop a rapid disk diffusion (RDD) method utilizing laser speckle formation (LSF) technology to expedite AST results. The study aimed to evaluate the performance of LSF technology in determining antimicrobial susceptibility. In this study, preclinical and clinical settings were established to compare the LSF technology with conventional disk diffusion (DD) methods to measure the inhibition zones. Preclinical experiments with different bacterial strains demonstrated more than 70% categorical agreement (CA) against most antimicrobials. Further, clinical experiments with multiple strains and antibiotics revealed CA ranging from 40 to 79%, while major and minor discrepancies were observed around 30% and 11%, respectively. These observations revealed high concordance between RDD and DD for multiple antimicrobials in multiple species. The results underscore the potential of RDD-based LSF technology for hastening AST procedures. The current study is marked by a unique equipment setup and analysis approach. Collectively, the suggested laser-based RDD showed greater potential than previously developed comparable methods. The proposed method and design have a higher application potential than formerly developed similar technologies. Together, the study contributes to the ongoing development of rapid AST methods.


Assuntos
Antibacterianos , Bactérias , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Lasers , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Humanos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos
2.
Am J Gastroenterol ; 114(9): 1478-1487, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31425154

RESUMO

OBJECTIVES: Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are 2 commonly ordered liver function tests, and ALT has long been considered more liver-specific than AST. Between the 2, the one which is better in predicting liver or non-liver-related mortality remains unsettled. METHODS: The cohort, 416,122 adults, came from a self-paying comprehensive health surveillance program during 1994-2008 and was followed up till 2008. Mortality came from National Death Index, with 10,412 deaths identified. Hazard ratios (HRs), computed by Cox model, and life expectancy, by life table method, were presented for 5 levels of AST and ALT with elevated AST or ALT defined as ≥40 IU/L. Liver disease included liver cancer and other liver conditions. RESULTS: There were 3 times more elevated ALT (15.4%) than AST (5.7%). However, those with elevated AST had higher mortality for all-cause (HR = 2.44), for liver disease (HR = 27.2), and for liver cancer (HR = 47.6) than its ALT counterparts (HR = 1.69, 10.8, and 20.2, respectively). Elevated AST also lost more years of life expectancy (10.2) than those lost by ALT (5.2) and larger than most common risks. Elevated AST had increased mortality from all cancers (HR = 3.57), stroke (HR = 1.36), respiratory diseases (HR = 1.34), and injuries (HR = 1.82), other than just liver disease. All-cause mortality remained significantly increased, when high risk groups were excluded, such as frequent drinkers, hepatitis carriers, those died from nonmedical conditions, those died in the first 3 years, or advanced fibrosis index based on 4 factors or aspartate transaminase-to-platelet ratio index. Results were consistent between those returned for second visits and those analyzed in initial visits. DISCUSSION: Those with elevated AST (≥40 IU/L) had life expectancy cut short by 10.2 years, doubled the number of years lost with elevated ALT. For all-cause and for liver-related mortality, AST was an important predictor, better than ALT.


Assuntos
Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , Expectativa de Vida , Hepatopatias/mortalidade , Adulto , Causas de Morte , Feminino , Humanos , Hepatopatias/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Mortalidade , Prognóstico , Modelos de Riscos Proporcionais
3.
Proc Natl Acad Sci U S A ; 109(39): 15900-5, 2012 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-23019374

RESUMO

Efficient worldwide swine surveillance for influenza A viruses is urgently needed; the emergence of a novel reassortant pandemic H1N1 (pH1N1) virus in 2009 demonstrated that swine can be the direct source of pandemic influenza and that the pandemic potential of viruses prevalent in swine populations must be monitored. We used the ferret model to assess the pathogenicity and transmissibility of predominant Korean triple-reassortant swine (TRSw) H1N2 and H3N2 influenza viruses genetically related to North American strains. Although most of the TRSw viruses were moderately pathogenic, one [A/Swine/Korea/1204/2009; Sw/1204 (H1N2)] was virulent in ferrets, causing death within 10 d of inoculation, and was efficiently transmitted to naive contact ferrets via respiratory droplets. Although molecular analysis did not reveal known virulence markers, the Sw/1204 virus acquired mutations in hemagglutinin (HA) (Asp-225-Gly) and neuraminidase (NA) (Ser-315-Asn) proteins during the single ferret passage. The contact-Sw/1204 virus became more virulent in mice, replicated efficiently in vitro, extensively infected human lung tissues ex vivo, and maintained its ability to replicate and transmit in swine. Reverse-genetics studies further indicated that the HA(225G) and NA(315N) substitutions contributed substantially in altering virulence and transmissibility. These findings support the continuing threat of some field TRSw viruses to human and animal health, reviving concerns on the capacity of pigs to create future pandemic viruses. Apart from warranting continued and enhanced global surveillance, this study also provides evidence on the emerging roles of HA(225G) and NA(315N) as potential virulence markers in mammals.


Assuntos
Furões/virologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A Subtipo H1N2/patogenicidade , Mutação , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/veterinária , Suínos/virologia , Fatores de Virulência/metabolismo , Animais , Linhagem Celular , Cães , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H1N2/metabolismo , Camundongos , Infecções por Orthomyxoviridae/genética , Doenças dos Suínos , Fatores de Virulência/genética
4.
Nat Commun ; 15(1): 243, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38172119

RESUMO

The thermal Hall effect in magnetic insulators has been considered a powerful method for examining the topological nature of charge-neutral quasiparticles such as magnons. Yet, unlike the kagome system, the triangular lattice has received less attention for studying the thermal Hall effect because the scalar spin chirality cancels out between adjacent triangles. However, such cancellation cannot be perfect if the triangular lattice is distorted. Here, we report that the trimerized triangular lattice of multiferroic hexagonal manganite YMnO3 produces a highly unusual thermal Hall effect under an applied magnetic field. Our theoretical calculations demonstrate that the thermal Hall conductivity is related to the splitting of the otherwise degenerate two chiralities of its 120˚ magnetic structure. Our result is one of the most unusual cases of topological physics due to this broken Z2 symmetry of the chirality in the supposedly paramagnetic state of YMnO3, due to strong topological spin fluctuations with the additional intricacy of a Dzyaloshinskii-Moriya interaction.

5.
Virol J ; 10: 104, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-23551908

RESUMO

BACKGROUND: Influenza vaccines are prepared annually based on global epidemiological surveillance data. However, since there is no method by which to predict the influenza strain that will cause the next pandemic, the demand to develop new vaccination strategies with broad cross-reactivity against influenza viruses are clearly important. The ectodomain of the influenza M2 protein (M2e) is an attractive target for developing a vaccine with broad cross-reactivity. For these reasons, we investigated the efficacy of an inactivated H9N2 virus vaccine (a-H9N2) mixed with M2e (1xM2e or 4xM2e) proteins expressed in Escherichia coli, which contains the consensus of sequence the extracellular domain of matrix 2 (M2e) of A/chicken/Vietnam/27262/09 (H5N1) avian influenza virus, and investigated its humoral immune response and cross-protection against influenza A viruses. RESULTS: Mice were intramuscularly immunized with a-H9N2, 1xM2e alone, 4xM2e alone, a-H9N2/1xM2e, or a-H9N2/4xM2e. Three weeks post-vaccination, mice were challenged with lethal homologous (A/ chicken /Korea/ma163/04, H9N2) or heterosubtypic virus (A/Philippines/2/82, H3N2 and A/aquatic bird/Korea/maW81/05, H5N2). Our studies demonstrate that the survival of mice immunized with a-H9N2/1xM2e or with a-H9N2/4xM2e (100% survival) was significantly higher than that of mouse-adapted H9N2 virus-infected mice vaccinated with 1xM2e alone or with 4xM2e alone (0% survival). We also evaluated the protective efficacy of the M2e + vaccine against infection with mouse-adapted H5N2 influenza virus. Protection from death in the control group (0% survival) was similar to that of the 1×M2e alone and 4xM2e alone-vaccinated groups (0% survival). Only 40% of mice vaccinated with vaccine alone survived challenge with H5N2, while the a-H9N2/1×M2e and a-H9N2/4×M2e groups showed 80% and 100% survival following mouse-adapted H5N2 challenge, respectively. We also examined cross-protection against human H3N2 virus and found that the a-H9N2/1×M2e group displayed partial cross-protection against H3N2 (40% survival), whereas vaccine alone, 1×M2e alone, 4×M2e alone, or H9N2/1×M2e groups showed incomplete protection (0% survival) in response to challenge with a lethal dose of human H3N2 virus. CONCLUSIONS: Taken together, these results suggest that prokaryote-expressed M2e protein improved inactivated H9N2 virus vaccine efficacy and achieved cross-protection against lethal influenza A virus infection in mice.


Assuntos
Vírus da Influenza A Subtipo H9N2/imunologia , Vacinas contra Influenza/imunologia , Proteínas da Matriz Viral/imunologia , Animais , Anticorpos Antivirais/sangue , Proteção Cruzada , Reações Cruzadas , Feminino , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/administração & dosagem , Injeções Intramusculares , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sobrevida , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
6.
Brain ; 135(Pt 4): 1055-69, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22434214

RESUMO

Inflammatory microenvironment signalling plays a crucial role in tumour progression (i.e. cancer cell proliferation, survival, angiogenesis and metastasis) in many types of human malignancies. However, the role of inflammation in brain tumour pathology remains poorly understood. Here, we report that interferon regulatory factor 7 is a crucial regulator of brain tumour progression and heterogeneity. Ectopic expression of interferon regulatory factor 7 in glioma cells promotes tumorigenicity, angiogenesis, microglia recruitment and cancer stemness in vivo and in vitro through induction of interleukin 6, C-X-C motif chemokine 1 and C-C motif chemokine 2. In particular, interferon regulatory factor 7-driven interleukin 6 plays a pivotal role in maintaining glioma stem cell properties via Janus kinase/signal transducer and activator of transcription-mediated activation of Jagged-Notch signalling in glioma cells and glioma stem cells derived from glioma patients. Accordingly, the short hairpin RNA-mediated depletion of interferon regulatory factor 7 in glioma stem cells markedly suppressed interleukin 6-Janus kinase/signal transducer and activator of transcription-mediated Jagged-Notch-signalling pathway, leading to decreases in glioma stem cell marker expression, tumoursphere-forming ability, and tumorigenicity. Furthermore, in a mouse model of wound healing, depletion of interferon regulatory factor 7 suppressed tumour progression and decreased cellular heterogeneity. Finally, interferon regulatory factor 7 was overexpressed in patients with high-grade gliomas, suggesting its potential as an independent prognostic marker for glioma progression. Taken together, our findings indicate that interferon regulatory factor 7-mediated inflammatory signalling acts as a major driver of brain tumour progression and cellular heterogeneity via induction of glioma stem cell genesis and angiogenesis.


Assuntos
Glioma/patologia , Fator Regulador 7 de Interferon/metabolismo , Interleucina-6/metabolismo , Células-Tronco Neoplásicas/fisiologia , Receptor Notch1/metabolismo , Transdução de Sinais/fisiologia , Antígeno AC133 , Antígenos CD/metabolismo , Astrócitos/metabolismo , Encéfalo/citologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células , Células Cultivadas , Quimiocina CCL2/metabolismo , Quimiocina CXCL1/metabolismo , Imunoprecipitação da Cromatina , Biologia Computacional , Células Endoteliais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Glicoproteínas/metabolismo , Humanos , Fator Regulador 7 de Interferon/genética , Neovascularização Patológica/induzido quimicamente , Neovascularização Patológica/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/fisiologia , Peptídeos/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução Genética/métodos , Ensaio Tumoral de Célula-Tronco
7.
J Virol ; 85(13): 6275-86, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21507962

RESUMO

Gene mutations and reassortment are key mechanisms by which influenza A virus acquires virulence factors. To evaluate the role of the viral polymerase replication machinery in producing virulent pandemic (H1N1) 2009 influenza viruses, we generated various polymerase point mutants (PB2, 627K/701N; PB1, expression of PB1-F2 protein; and PA, 97I) and reassortant viruses with various sources of influenza viruses by reverse genetics. Although the point mutations produced no significant change in pathogenicity, reassortment between the pandemic A/California/04/09 (CA04, H1N1) and current human and animal influenza viruses produced variants possessing a broad spectrum of pathogenicity in the mouse model. Although most polymerase reassortants had attenuated pathogenicity (including those containing seasonal human H3N2 and high-pathogenicity H5N1 virus segments) compared to that of the parental CA04 (H1N1) virus, some recombinants had significantly enhanced virulence. Unexpectedly, one of the five highly virulent reassortants contained a A/Swine/Korea/JNS06/04(H3N2)-like PB2 gene with no known virulence factors; the other four had mammalian-passaged avian-like genes encoding PB2 featuring 627K, PA featuring 97I, or both. Overall, the reassorted polymerase complexes were only moderately compatible for virus rescue, probably because of disrupted molecular interactions involving viral or host proteins. Although we observed close cooperation between PB2 and PB1 from similar virus origins, we found that PA appears to be crucial in maintaining viral gene functions in the context of the CA04 (H1N1) virus. These observations provide helpful insights into the pathogenic potential of reassortant influenza viruses composed of the pandemic (H1N1) 2009 influenza virus and prevailing human or animal influenza viruses that could emerge in the future.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Infecções por Orthomyxoviridae/virologia , Pandemias , RNA Polimerase Dependente de RNA/genética , Vírus Reordenados/patogenicidade , Animais , Linhagem Celular , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação Puntual , RNA Polimerase Dependente de RNA/metabolismo , Vírus Reordenados/genética , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência/genética , Replicação Viral/genética
8.
Arch Virol ; 157(6): 1039-50, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22402914

RESUMO

Human respiratory syncytial virus (HRSV) is the most common respiratory pathogen among infants and young children. To investigate the prevalence and genetic characteristics of HRSVs circulating in South Korea, we analyzed medical records of patients and performed molecular analysis of the G-protein gene of viruses detected from nasopharyngeal aspirates (NPA) of admitted patients at the Pediatrics Department of Chungbuk National University Hospital from April 2008 to April 2010. Epidemiological data revealed that the prevalence of HRSV infection was high during both winter seasons (October 2008 to February 2009 and November 2009 to February 2010). Of the 297 positive NPA specimens from infants or children tested, 67% were identified as HRSV-A while 33% were HRSV-B. The HRSV subgroup B was the most dominant in December 2008, but its dominance was dramatically replaced by HRSV subgroup A strains by February 2009. Phylogenetic analysis of the G protein sequences of HRSVs revealed novel genotypes within the HRSV-A (genotype CB-A) and B (genotypes BA11 and CB-B) subgroups in South Korea in addition to other strains identified in other countries. Molecular analysis also revealed genetic variability at the C-terminal end of the G proteins of the two HRSV subgroups, suggesting selection pressure in this region, which may potentially impact immune recognition. This is the first report of these HRSV variants in South Korea, indicating active genetic evolution of HRSV strains. Therefore, this study provides information on the molecular epidemiology of current HRSVs in the country and presents data for comparative analysis with other HRSV strains circulating worldwide.


Assuntos
Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/isolamento & purificação , Sequência de Aminoácidos , Criança , Criança Hospitalizada , Pré-Escolar , Variação Genética , Humanos , Lactente , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , República da Coreia/epidemiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/terapia , Vírus Sincicial Respiratório Humano/classificação , Alinhamento de Sequência , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
9.
Adv Mater ; 34(42): e2205825, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36069028

RESUMO

Interaction between dipoles often emerges intriguing physical phenomena, such as exchange bias in the magnetic heterostructures and magnetoelectric effect in multiferroics, which lead to advances in multifunctional heterostructures. However, the defect-dipole tends to be considered the undesired to deteriorate the electronic functionality. Here, deterministic switching between the ferroelectric and the pinched states by exploiting a new substrate of cubic perovskite, BaZrO3 is reported, which boosts the square-tensile-strain to BaTiO3 and promotes four-variants in-plane spontaneous polarization with oxygen vacancy creation. First-principles calculations propose a complex of an oxygen vacancy and two Ti3+ ions coins a charge-neutral defect-dipole. Cooperative control of the defect-dipole and the spontaneous polarization reveals ternary in-plane polar states characterized by biased/pinched hysteresis loops. Furthermore, it is experimentally demonstrated that three electrically controlled polar-ordering states lead to switchable and nonvolatile dielectric states for application of nondestructive electro-dielectric memory. This discovery opens a new route to develop functional materials via manipulating defect-dipoles and offers a novel platform to advance heteroepitaxy beyond the prevalent perovskite substrates.

10.
J Gen Virol ; 92(Pt 1): 36-50, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20861321

RESUMO

To investigate whether currently circulating H9N2 avian influenza viruses (AIVs) in domestic poultry have evolved in Korean poultry since 2007, genetic and serological comparisons were conducted of H9N2 isolates from poultry slaughterhouses from January 2008 to December 2009. The isolation rate was relatively low in 2008 but increased gradually from January 2009 onwards. Genetic and phylogenetic analyses revealed that reassortant viruses had emerged, generating at least five novel genotypes, mostly containing segments of a previously prevalent domestic H9N2 virus lineage (Ck/Korea/04116/04-like). It was noteworthy that the N2 genes of some H9N2 isolates (genotypes D, E and F) were derived from those of H3N2-like viruses commonly isolated among domestic ducks in live-poultry markets. Animal challenge studies demonstrated that the pathogenicity of Ck/Korea/SH0906/09 (genotype B) and Ck/Korea/SH0912/09 (genotype F) in domestic avian species was altered due to reassortment. Furthermore, serological analysis revealed that the isolates were antigenically distinct from previous Korean H9N2 viruses including Ck/Korea/01310/01. Such antigenic diversity was illustrated further in experiments using H9N2-immunized chickens, which could not inhibit the replication and transmission of challenge viruses from each genotype. These results suggest that H9N2 viruses from domestic poultry have undergone substantial evolution since 2007 by immune selection as a result of vaccinal and natural immunity, coupled with reassortment. Taken together, this study demonstrates that periodical updating of vaccine strains, based on continuous surveillance data, is an important issue in order to provide sufficient protectivity against AIV infections.


Assuntos
Evolução Molecular , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Matadouros , Animais , Análise por Conglomerados , Genótipo , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/patogenicidade , Influenza Aviária/patologia , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Aves Domésticas , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Vírus Reordenados/patogenicidade , República da Coreia , Análise de Sequência de DNA , Proteínas Virais/genética , Virulência
11.
Biochem Biophys Res Commun ; 414(1): 153-8, 2011 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-21945618

RESUMO

Staufen1 (Stau1), a host cellular protein, along with non-structural protein 1 (NS1), an influenza viral protein, associate with each other during influenza viral infection and down-regulation of Stau1 by RNA interference reduces the yield of influenza A virus, suggesting a role for Stau1 in viral replication. In order to develop a new tool to control influenza A virus, we determined the specific regions of Staufen1 protein involved in the interaction with NS1. The linker between RBD3 and 4 was isolated as the binding regions. Expression of RBD3L, the linker including RBD3, inhibited the interaction between Stau1 and NS1, reducing the colocalization of the two proteins in the cytosol and nucleus regions. In addition, yield of influenza A virus in RBD3L-expressing cells was significantly reduced 36 h after infection. These results suggest that disruption of the Stau1-NS1 interaction can be used to control replication of influenza A virus, thereby providing a target for the development of antiviral drugs.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Domínios e Motivos de Interação entre Proteínas , Proteínas de Ligação a RNA/metabolismo , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Células HEK293 , Humanos , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética
12.
Biochem Biophys Res Commun ; 414(3): 569-74, 2011 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-21982772

RESUMO

Influenza A virus infection stimulates a wide range of virus-supportive or antiviral mechanisms in host cells. p21-Activated kinase 1 (PAK1) is a serine/threonine kinase that regulates a number of fundamental cellular processes and has been implicated in the modulation of virus replication. Here, we investigated the role of PAK1 activation during influenza A virus infection and found that virus propagation corresponded to stimulated PAK1 phosphorylation. Moreover, transfection of the active form of PAK1 (PAK1-T423E) in A549 cells induced higher viral titers (∼10-fold differences) compared to that in the control vector or inactive PAK1 (PAK1-K299R)-transfected cells. PAK1-specific siRNA knockdown also resulted in 10-100-fold reductions in virus yields compared to that in the control siRNA-treatment (p<0.05). We further showed that treatment with PAK18, a PAK1 peptide inhibitor, resulted in marked suppression of both ERK 1/2 phosphorylation and infectious virus production, which was comparable to that by U0126, a specific MEK/ERK inhibitor. These results provide evidence for the importance of PAK1 activation during influenza virus infection and its association with ERK in regulating virus replication. The present study also implicates PAK1 as a potential therapeutic target for managing influenza virus infections.


Assuntos
Vírus da Influenza A/fisiologia , Influenza Humana/enzimologia , Influenza Humana/virologia , Replicação Viral , Quinases Ativadas por p21/fisiologia , Linhagem Celular , Ativação Enzimática , Deleção de Genes , Técnicas de Silenciamento de Genes , Humanos , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases , RNA Interferente Pequeno/genética , Quinases Ativadas por p21/genética , Quinases raf/metabolismo
13.
J Am Chem Soc ; 132(4): 1216-7, 2010 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-20052975

RESUMO

We report a two-photon fluorescent probe (ASS) that can be excited by 780 nm femtosecond pulses and detect thiols in live cells and living tissues at a 90-180 microm depth without interference from other biologically relevant species by two-photon microscopy.


Assuntos
Corantes Fluorescentes/química , Compostos de Sulfidrila/análise , Animais , Química Encefálica , Células HeLa , Humanos , Metilaminas/química , Microscopia de Fluorescência , Estrutura Molecular , Naftalenos/química , Fótons , Ratos
14.
J Clin Microbiol ; 48(9): 3204-11, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20610681

RESUMO

As the pandemic (H1N1) 2009 influenza virus continues to infect human populations globally, reports on epidemiologically linked animal infections are also on the rise. Since December 2009, pandemic (H1N1) 2009-like viruses have been isolated in pigs from different swine farms of South Korea. Genetic and phylogenetic analyses of viral segments demonstrated several events of human-to-swine transmission with no apparent signs of reassortment. These events were also supported by serological surveillance in pig sera collected from April to December, suggesting that reverse transmission probably started between June and July with a drastic increase in prevalence the following months. Although molecular characterization indicates that the swine isolates are generally stable, some viruses are genetically evolving, most notably in their surface proteins. Animal studies (ferrets and mice) reveal that swine pandemic isolates epitomize biological properties attributed to the currently circulating human pandemic viruses, including replication kinetics and efficient transmission, indicating their potential to return to circulation among humans. Overall, these results indicate widespread human-to-animal transmission of pandemic (H1N1) 2009 influenza viruses in South Korea. With the significant role of pigs in the ecology of influenza viruses, these transmission events should be closely monitored and minimized to prevent the risk of generating viruses with greater human health concerns.


Assuntos
Transmissão de Doença Infecciosa , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/transmissão , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Animais , Anticorpos Antivirais/sangue , Análise por Conglomerados , Modelos Animais de Doenças , Furões , Humanos , Influenza Humana/virologia , Camundongos , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Prevalência , RNA Viral/genética , República da Coreia/epidemiologia , Análise de Sequência de DNA , Homologia de Sequência , Suínos
15.
J Virol ; 83(9): 4205-15, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19359528

RESUMO

Due to dual susceptibility to both human and avian influenza A viruses, pigs are believed to be effective intermediate hosts for the spread and production of new viruses with pandemic potential. In early 2008, two swine H5N2 viruses were isolated from our routine swine surveillance in Korea. The sequencing and phylogenetic analysis of surface proteins revealed that the Sw/Korea/C12/08 and Sw/Korea/C13/08 viruses were derived from avian influenza viruses of the Eurasian lineage. However, although the Sw/Korea/C12/08 isolate is an entirely avian-like virus, the Sw/Korea/C13/08 isolate is an avian-swine-like reassortant with the PB2, PA, NP, and M genes coming from a 2006 Korean swine H3N1-like virus. The molecular characterization of the two viruses indicated an absence of significant mutations that could be associated with virulence or binding affinity. However, animal experiments showed that the reassortant Sw/Korea/C13/08 virus was more adapted and was more readily transmitted than the purely avian-like virus in a swine experimental model but not in ferrets. Furthermore, seroprevalence in swine sera from 2006 to 2008 suggested that avian H5 viruses have been infecting swine since 2006. Although there are no known potential clinical implications of the avian-swine reassortant virus for pathogenicity in pigs or other species, including humans, at present, the efficient transmissibility of the swine-adapted H5N2 virus could facilitate virus spread and could be a potential model for pandemic, highly pathogenic avian influenza (e.g., H5N1 and H7N7) virus outbreaks or a pandemic strain itself.


Assuntos
Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Doenças dos Suínos/virologia , Suínos/virologia , Sequência de Aminoácidos , Animais , Antígenos Virais/imunologia , Furões , Vírus da Influenza A Subtipo H5N2/imunologia , Coreia (Geográfico) , Infecções por Orthomyxoviridae/sangue , Infecções por Orthomyxoviridae/patologia , Filogenia , Homologia de Sequência , Suínos/sangue , Suínos/imunologia , Doenças dos Suínos/sangue , Doenças dos Suínos/imunologia , Doenças dos Suínos/patologia , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo
16.
J Virol ; 83(23): 12325-35, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19793828

RESUMO

Adaptation of influenza A viruses to a new host species usually involves the mutation of one or more of the eight viral gene segments, and the molecular basis for host range restriction is still poorly understood. To investigate the molecular changes that occur during adaptation of a low-pathogenic avian influenza virus subtype commonly isolated from migratory birds to a mammalian host, we serially passaged the avirulent wild-bird H5N2 strain A/Aquatic bird/Korea/W81/05 (W81) in the lungs of mice. The resulting mouse-adapted strain (ma81) was highly virulent (50% mouse lethal dose = 2.6 log(10) 50% tissue culture infective dose) and highly lethal. Nonconserved mutations were observed in six viral genes (those for PB2, PB1, PA, HA, NA, and M). Reverse genetic experiments substituting viral genes and mutations demonstrated that the PA gene was a determinant of the enhanced virulence in mice and that a Thr-to-Iso substitution at position 97 of PA played a key role. In growth kinetics studies, ma81 showed enhanced replication in mammalian but not avian cell lines; the PA(97I) mutation in strain W81 increased its replicative fitness in mice but not in chickens. The high virulence associated with the PA(97I) mutation in mice corresponded to considerably enhanced polymerase activity in mammalian cells. Furthermore, this characteristic mutation is not conserved among avian influenza viruses but is prevalent among mouse-adapted strains, indicating a host-dependent mutation. To our knowledge, this is the first study that the isoleucine residue at position 97 in PA plays a key role in enhanced virulence in mice and is implicated in the adaptation of avian influenza viruses to mammalian hosts.


Assuntos
Adaptação Biológica , Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N2/patogenicidade , RNA Polimerase Dependente de RNA/fisiologia , Proteínas Virais/fisiologia , Fatores de Virulência/fisiologia , Animais , Doenças das Aves/virologia , Aves , Linhagem Celular , Engenharia Genética , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Influenza Aviária/virologia , Coreia (Geográfico) , Dose Letal Mediana , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação de Sentido Incorreto , Infecções por Orthomyxoviridae/virologia , RNA Polimerase Dependente de RNA/genética , Inoculações Seriadas , Análise de Sobrevida , Proteínas Virais/genética , Fatores de Virulência/genética
17.
Arch Virol ; 155(2): 229-41, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20033463

RESUMO

Surveillance of H9 avian influenza viruses in Korean live-poultry markets from September 2004 through October 2007 was carried out to investigate active reassortment between wild migratory birds and domestic poultry in Korea. Antigenic and phylogenetic analyses showed that most of the isolates belong to the previous Korean H9N2-like lineage and differ from the southeastern Chinese strains. Interestingly, the Ck/Korea/LPM77/06 group (genotype B) and Dk/Korea/LPM248/07 group (genotype C) showed unique properties distinct from those of other Korean H9N2 strains. Although the HA genes of these two groups belong to Korean H9N2-like lineage, the PA genes closely resemble those of the Chinese Y280-like lineage. In addition, the PB2 genes of the Dk/Korea/LPM248/07 group were closely related to those isolated from migratory birds. Several other isolates also clustered within the H9N2 B genotype, an indication that there are at least two predominant H9N2 influenza genotypes in Korea. Another isolate, Dk/Korea/LPM71/06, was identified as an H9N1 subtype, the first ever discovered in Korean live-poultry markets. These findings reveal that reassortment of Korean H9 influenza viruses has occurred frequently in live-poultry markets and may have been mediated by introduction of genetic material from viruses circulating among migratory wild birds to domestic birds. Consequently, the new dominant H9N2 genotypes have become established in Korean live-poultry markets through continued reassortment.


Assuntos
Doenças das Aves/virologia , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Vírus Reordenados/genética , Recombinação Genética , Animais , Antígenos Virais/análise , Aves , Análise por Conglomerados , Genótipo , Hemaglutininas Virais/genética , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/imunologia , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Orthomyxoviridae , Filogenia , RNA Polimerase Dependente de RNA/genética , Vírus Reordenados/isolamento & purificação , República da Coreia , Proteínas Virais/genética
18.
Electrolyte Blood Press ; 18(1): 1-9, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32655650

RESUMO

BACKGROUND: Urinary concentration impairment is a major feature of cyclosporine nephrotoxicity. METHODS: We explored two possible mechanisms that may underlie cyclosporine-induced polyuria; water, and/or osmotic diuresis. Cyclosporine was subcutaneously injected to normal salt-fed Sprague-Dawley rats at a daily dose of 25mg/kg for 2 weeks (Experiment I) and 7.5mg/kg for 6 weeks (Experiment II). RESULTS: In Experiment I, cyclosporine treatment caused an increase in urine volume (2.7±0.5 vs. 10.3±1.13mL/d/100 g BW, p<0.001) and a decrease in urine osmolality (2,831±554 vs. 1,379±478mOsm/kg H2O, p<0.05). Aquaporin-2 (AQP2) protein expression decreased in cyclosporine-treated rat kidneys (cortex, 78±8%, p<0.05; medulla, 80±1%, p<0.05). Experiment II also showed that urine volume was increased by cyclosporine treatment (4.97±0.66 vs. 9.65±1.76mL/d/100 g BW, p<0.05). Whereas urine osmolality was not affected, urinary excretion of osmoles was increased (7.5±0.4 vs. 14.9±1.4mosmoles/d/100 g BW, p<0.005). Notably, urinary excretion of glucose increased in cyclosporine-treated rats (7±1 vs. 10,932±2,462 mg/d/100 g BW, p<0.005) without a significant elevation in plasma glucose. In both Experiment I and II, GLUT2 protein expression in the renal cortex was decreased by cyclosporine treatment (Experiment I, 55±6%, p<0.005; Experiment II, 88±3%, p<0.05). CONCLUSION: Both water diuresis and osmotic diuresis are induced by cyclosporine nephrotoxicity. AQP2 and GLUT2 downregulation may underlie water and osmotic diuresis, respectively.

19.
Head Neck ; 41(4): 924-929, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30723988

RESUMO

BACKGROUND: Salivary gland neoplasms are relatively rare and comprise only 1%-4% of all human neoplasms. Salivary gland neoplasms also show an extremely wide range of morphological diversity. Currently, the genetic alterations and corresponding molecular mechanisms underlying salivary gland neoplasms development remain largely unknown. METHOD: We generated an inducible Tet-MAP3K8::MMTV-rTA mouse model by crossing the MAP3K8 transgenic mice with MMTR-rTA transgenic mice to express MAP3K8 in the salivary gland. RESULTS: MAP3K8 overexpression in the murine salivary glands of Tet-MAP3K8::MMTR-rTA transgenic mice induces tumorigenesis. Pathological investigations reveal partial fibrosis and adenosis of salivary glands, and foci of atypical squamoid cellular proliferation, which represent invasive squamous cell carcinoma (SCC). CONCLUSION: MAP3K8 overexpression is associated with SCC development in murine salivary glands. It provides an in vivo framework for the understanding of molecular mechanisms underlying SCC development in the salivary glands and also for the development of a future therapeutic strategy targeting this tumor type.


Assuntos
Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/genética , MAP Quinase Quinase Quinases/genética , Proteínas Proto-Oncogênicas/genética , Neoplasias das Glândulas Salivares/patologia , Regulação para Cima/genética , Animais , Biópsia por Agulha , Carcinoma de Células Escamosas/genética , Transformação Celular Neoplásica/patologia , Células Cultivadas , Modelos Animais de Doenças , Células Epiteliais , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Transgênicos , Distribuição Aleatória , República da Coreia , Neoplasias das Glândulas Salivares/genética , Sensibilidade e Especificidade
20.
Adv Mater ; 31(24): e1808104, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31034128

RESUMO

Ferroelectricity occurs in crystals with broken spatial inversion symmetry. In conventional perovskite oxides, concerted ionic displacements within a 3D network of transition-metal-oxygen polyhedra (MOx ) manifest spontaneous polarization. Meanwhile, some 2D networks of MOx foster geometric ferroelectricity with magnetism, owing to the distortion of the polyhedra. Because of the fundamentally different mechanism of ferroelectricity in a 2D network, one can further challenge an uncharted mechanism of ferroelectricity in a 1D channel of MOx and estimate its feasibility. Here, ferroelectricity and coupled ferromagnetism in a 1D FeO4 tetrahedral chain network of a brownmillerite SrFeO2.5 epitaxial thin film are presented. The result provides a new paradigm for designing low-dimensional MOx networks, which is expected to benefit the realization of macroscopic ferro-ordering materials including ferroelectric ferromagnets.

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