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1.
Int J Mol Sci ; 23(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35328733

RESUMO

Voltage-gated Kv1.3 potassium channels are essential for maintaining negative membrane potential during T-cell activation. They interact with membrane-associated guanylate kinases (MAGUK-s) via their C-terminus and with TCR/CD3, leading to enrichment at the immunological synapse (IS). Molecular interactions and mobility may impact each other and the function of these proteins. We aimed to identify molecular determinants of Kv1.3 mobility, applying fluorescence correlation spectroscopy on human Jurkat T-cells expressing WT, C-terminally truncated (ΔC), and non-conducting mutants of mGFP-Kv1.3. ΔC cannot interact with MAGUK-s and is not enriched at the IS, whereas cells expressing the non-conducting mutant are depolarized. Here, we found that in standalone cells, mobility of ΔC increased relative to the WT, likely due to abrogation of interactions, whereas mobility of the non-conducting mutant decreased, similar to our previous observations on other membrane proteins in depolarized cells. At the IS formed with Raji B-cells, mobility of WT and non-conducting channels, unlike ΔC, was lower than outside the IS. The Kv1.3 variants possessing an intact C-terminus had lower mobility in standalone cells than in IS-engaged cells. This may be related to the observed segregation of F-actin into a ring-like structure at the periphery of the IS, leaving much of the cell almost void of F-actin. Upon depolarizing treatment, mobility of WT and ΔC channels decreased both in standalone and IS-engaged cells, contrary to non-conducting channels, which themselves caused depolarization. Our results support that Kv1.3 is enriched at the IS via its C-terminal region regardless of conductivity, and that depolarization decreases channel mobility.


Assuntos
Canal de Potássio Kv1.3/metabolismo , Linfócitos T , Actinas/metabolismo , Humanos , Canal de Potássio Kv1.3/genética , Potenciais da Membrana , Sinapses/metabolismo , Linfócitos T/metabolismo
2.
Antimicrob Agents Chemother ; 65(12): e0116721, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34516245

RESUMO

4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA, MK-8591, islatravir) is a nucleoside reverse transcriptase translocation inhibitor (NRTTI) with exceptional potency against wild-type (WT) and drug-resistant HIV-1 in phase III clinical trials. EFdA resistance is not well characterized. To study EFdA resistance patterns that may emerge in naive or tenofovir (TFV)-, emtricitabine/lamivudine (FTC/3TC)-, or zidovudine (AZT)-treated patients, we performed viral passaging experiments starting with WT, K65R, M184V, or D67N/K70R/T215F/K219Q HIV-1. Regardless of the starting viral sequence, all selected EFdA-resistant variants included the M184V reverse transcriptase (RT) mutation. Using recombinant viruses, we validated the role for M184V as the primary determinant of EFdA resistance; none of the observed connection subdomain (R358K and E399K) or RNase H domain (A502V) mutations significantly contributed to EFdA resistance. A novel EFdA resistance mutational pattern that included A114S was identified in the background of M184V. A114S/M184V exhibited higher EFdA resistance (∼24-fold) than either M184V (∼8-fold) or A114S alone (∼2-fold). Remarkably, A114S/M184V and A114S/M184V/A502V resistance mutations were up to 50-fold more sensitive to tenofovir than was WT HIV-1. These mutants also had significantly lower specific infectivities than did WT. Biochemical experiments confirmed decreases in the enzymatic efficiency (kcat/Km) of WT versus A114S (2.1-fold) and A114S/M184V/A502V (6.5-fold) RTs, with no effect of A502V on enzymatic efficiency or specific infectivity. The rather modest EFdA resistance of M184V or A114S/M184V (8- and 24-fold), their hypersusceptibility to tenofovir, and strong published in vitro and in vivo data suggest that EFdA is an excellent therapeutic candidate for naive, AZT-, FTC/3TC-, and especially tenofovir-treated patients.


Assuntos
HIV-1 , Inibidores da Transcriptase Reversa , Desoxiadenosinas/farmacologia , HIV-1/genética , Humanos , Lamivudina , Inibidores da Transcriptase Reversa/farmacologia
3.
Vet Res ; 52(1): 60, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883034

RESUMO

Influenza A viruses (IAVs) are common causes of respiratory infection in pigs. The objective of this study was to characterize the circulation of IAVs between weaning and market age on the basis of development of antibody response and molecular epidemiology of detected viruses. Two batches of weaned pigs were followed in the nursery and finisher barns with a sample of 81 and 75 pigs. Nasal swabs and blood samples were collected from individual pigs for virological and serological analyses. A H3N2 subtype virus, of cluster IV, was detected in Study 1, with a maximum of 97.9% identity to HA gene of viruses previously isolated in Ontario. In Study 2, a H1N1 subtype virus, of 2009 H1N1 pandemic lineage, was detected, with a maximum of 97.8% identity to HA gene of viruses previously isolated in Ontario. On the basis of HA gene, it was observed that pigs were being detected with the same virus over time. The existence of antibody titers for IAV other than the isolated one confirmed that more than one subtype can circulate in the same population. In Study 1, pigs with higher numbers of IAV detection had lower serological titers for the same virus that was confirmed to circulate in the nursery (P < 0.01). Thorough knowledge of all endemic viral strains is fundamental for development of infection and disease control, particularly in complex production systems. This may include consideration of sampling and testing strategies which could detect circulation of all IAV variants, even if they have low prevalence.


Assuntos
Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/fisiologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/epidemiologia , Criação de Animais Domésticos , Animais , Anticorpos Antivirais/sangue , Formação de Anticorpos , Feminino , Incidência , Epidemiologia Molecular , Ontário/epidemiologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Prevalência , Sus scrofa/crescimento & desenvolvimento , Suínos , Doenças dos Suínos/virologia , Desmame
4.
Adv Exp Med Biol ; 1334: 1-22, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34476742

RESUMO

The flipped classroom (where students prepare before and then develop understanding during class) and technology-enhanced learning (audio-visual learning tools) are increasingly used to supplement anatomy teaching. However, the supporting literature lacks robust methodology and is conflicting in demonstrating efficacy outcomes. Contrastingly, near-peer teaching (where senior students teach juniors on the same academic programme) is well researched and reported to be both effective and versatile. This provides an ideal vehicle in which to investigate and potentially optimise these approaches.This study aims to assess educational impact of the peer-led flipped model and student engagement and perceptions regarding traditional and TEL resources.A quasi-randomised, cross-sectional study was conducted with 281 second-year University of Southampton medical students. Students were randomly allocated to 3 groups: traditional lecture (control), flipped text resource, or flipped video resource. The first group received no pre-teaching material, but the flipped groups received a text or video pre-teaching resource. Objective outcomes measured were: Knowledge gain and retention via multiple-choice questionnaires and formative exams Student perceptions and engagement using questionnaires and 2 focus groups All groups demonstrated significant knowledge gain post-teaching (p < 0.0001). However, regardless of engagement with pre-teaching material, no significant difference was found in knowledge gain or retention between the groups. Students engaged 21.1% more with the text rather than video resource (p = 0.0019), but spent equal time using both (p = 0.0948). All resources and teaching approaches were perceived 'very useful' with no significant differences found between groups. A qualitative approach utilising thematic analysis of focus groups identified 4 themes, including 'Attitudes towards flipped classroom', which revealed mixed reviews and perceptions from participants.This study has found the peer-led flipped model is of no detriment to educational impact compared to peer-led traditional approaches in a well-established peer teaching programme in undergraduate medicine at the University of Southampton. Students value traditional and video resources but engage with them differently. Additionally, it was reported that in this experiment, NPT did not seem well suited to the flipped classroom, suggesting a rare limitation of the utility of NPT application within an anatomy curriculum.


Assuntos
Neuroanatomia , Estudantes de Medicina , Estudos Transversais , Currículo , Humanos , Aprendizagem
5.
Genome Res ; 27(6): 1063-1073, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28341774

RESUMO

The impact of R-loops on the physiology and pathology of chromosomes has been demonstrated extensively by chromatin biology research. The progress in this field has been driven by technological advancement of R-loop mapping methods that largely relied on a single approach, DNA-RNA immunoprecipitation (DRIP). Most of the DRIP protocols use the experimental design that was developed by a few laboratories, without paying attention to the potential caveats that might affect the outcome of RNA-DNA hybrid mapping. To assess the accuracy and utility of this technology, we pursued an analytical approach to estimate inherent biases and errors in the DRIP protocol. By performing DRIP-sequencing, qPCR, and receiver operator characteristic (ROC) analysis, we tested the effect of formaldehyde fixation, cell lysis temperature, mode of genome fragmentation, and removal of free RNA on the efficacy of RNA-DNA hybrid detection and implemented workflows that were able to distinguish complex and weak DRIP signals in a noisy background with high confidence. We also show that some of the workflows perform poorly and generate random answers. Furthermore, we found that the most commonly used genome fragmentation method (restriction enzyme digestion) led to the overrepresentation of lengthy DRIP fragments over coding ORFs, and this bias was enhanced at the first exons. Biased genome sampling severely compromised mapping resolution and prevented the assignment of precise biological function to a significant fraction of R-loops. The revised workflow presented herein is established and optimized using objective ROC analyses and provides reproducible and highly specific RNA-DNA hybrid detection.


Assuntos
Linfócitos T CD4-Positivos/química , Mapeamento Cromossômico/métodos , DNA/isolamento & purificação , Imunoprecipitação/métodos , RNA/isolamento & purificação , Artefatos , Pareamento de Bases , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Misturas Complexas/química , DNA/genética , DNA/metabolismo , Enzimas de Restrição do DNA/química , Fixadores/química , Formaldeído/química , Humanos , Células Jurkat , Extração Líquido-Líquido/métodos , Hibridização de Ácido Nucleico , Cultura Primária de Células , RNA/genética , RNA/metabolismo , Curva ROC , Extração em Fase Sólida/métodos
6.
Virol J ; 17(1): 16, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005267

RESUMO

BACKGROUND: Aquatic bird bornavirus 1 (ABBV-1) has been associated with neurological diseases in wild waterfowls. In Canada, presence of ABBV-1 was demonstrated by RT-qPCR and immunohistochemistry in tissues of waterfowls with history of neurological disease and inflammation of the central and peripheral nervous tissue, although causation has not been proven by pathogenesis experiments, yet. To date, in vitro characterization of ABBV-1 is limited to isolation in primary duck embryo fibroblasts. The objectives of this study were to describe isolation of ABBV-1 in primary duck embryonic fibroblasts (DEF), and characterize replication in DEF and three immortalized avian fibroblast cell lines (duck CCL-141, quail QT-35, chicken DF-1) in order to evaluate cellular permissivity and identify suitable cell lines for routine virus propagation. METHODS: The virus was sequenced, and phylogenetic analysis performed on a segment of the N gene coding region. Virus spread in cell cultures, viral RNA and protein production, and titres were evaluated at different passages using immunofluorescence, RT-qPCR, western blotting, and tissue culture dose 50% (TCID50) assay, respectively. RESULTS: The isolated ABBV-1 showed 97 and 99% identity to European ABBV-1 isolate AF-168 and North American ABBV-1 isolates 062-CQ and CG-N1489, and could infect and replicate in DEF, CCL-141, QT-35 and DF-1 cultures. Viral RNA was detected in all four cultures with highest levels observed in DEF and CCL-141, moderate in QT-35, and lowest in DF-1. N protein was detected in western blots from infected DEF, CCL-141 and QT-35 at moderate to high levels, but minimally in infected DF-1. Infectious titre was highest in DEF (between approximately 105 to 106 FFU / 106 cells). Regarding immortalized cell lines, CCL-141 showed the highest titre between approximately 104 to 105 FFU / 106 cells. DF-1 produced minimal infectious titre. CONCLUSIONS: This study confirms the presence of ABBV-1 among waterfowl in Canada and reported additional in vitro characterization of this virus in different avian cell lines. ABBV-1 replicated to highest titre in DEF, followed by CCL-141 and QT-35, and poorly in DF-1. Our results showed that CCL-141 can be used instead of DEF for routine ABBV-1 production, if a lower titre is an acceptable trade-off for the simplicity of using immortalized cell line over primary culture.


Assuntos
Bornaviridae/isolamento & purificação , Bornaviridae/fisiologia , Fibroblastos/virologia , Replicação Viral , Animais , Doenças das Aves/virologia , Bornaviridae/classificação , Canadá , Técnicas de Cultura de Células , Linhagem Celular Transformada , Galinhas/virologia , Patos/virologia , Filogenia , Codorniz/virologia
7.
Int J Mol Sci ; 21(5)2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32106594

RESUMO

The immunological synapse (IS) is a specialized contact area formed between a T cell and an antigen presenting cell (APC). Besides molecules directly involved in antigen recognition such as the TCR/CD3 complex, ion channels important in the membrane potential and intracellular free Ca2+ concentration control of T cells are also recruited into the IS. These are the voltage-gated Kv1.3 and Ca2+-activated KCa3.1 K+ channels and the calcium release-activated Ca2+ channel (CRAC). However, the consequence of this recruitment on membrane potential and Ca2+ level control is not known. Here we demonstrate that the membrane potential (MP) of murine T cells conjugated with APCs in an IS shows characteristic oscillations. We found that depolarization of the membrane by current injection or by increased extracellular K+ concentration produced membrane potential oscillations (MPO) significantly more frequently in conjugated T cells than in lone T cells. Furthermore, oscillation of the free intracellular Ca2+ concentration could also be observed more frequently in cells forming an IS than in lone cells. We suggest that in the IS the special arrangement of channels and the constrained space between the interacting cells creates a favorable environment for these oscillations, which may enhance the signaling process leading to T cell activation.


Assuntos
Sinalização do Cálcio , Sinapses Imunológicas/metabolismo , Potenciais da Membrana , Linfócitos T/metabolismo , Animais , Células Apresentadoras de Antígenos/metabolismo , Células Apresentadoras de Antígenos/fisiologia , Cálcio/metabolismo , Canais de Cálcio Ativados pela Liberação de Cálcio/metabolismo , Linhagem Celular , Sinapses Imunológicas/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Canal de Potássio Kv1.3/metabolismo , Camundongos , Potássio/metabolismo , Linfócitos T/fisiologia
8.
Biophys J ; 114(10): 2473-2482, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29754714

RESUMO

The high electric field across the plasma membrane might influence the conformation and behavior of transmembrane proteins that have uneven charge distributions in or near their transmembrane regions. Membrane depolarization of T cells occurs in the tumor microenvironment and in inflamed tissues because of K+ release from necrotic cells and hypoxia affecting the expression of K+ channels. However, little attention has been given to the effect of membrane potential (MP) changes on membrane receptor function. Therefore, we studied the influence of membrane de- and hyperpolarization on the biophysical properties and signaling of interleukin-2 (IL-2) and interleukin-15 (IL-15) receptors, which play important roles in T cell function. We investigated the mobility, clustering, and signaling of these receptors and major histocompatibility complex (MHC) I/II glycoproteins forming coclusters in lipid rafts of T cells. Depolarization by high K+ buffer or K+ channel blockers resulted in a decrease in the mobility of IL-2Rα and MHC glycoproteins, as shown by fluorescence correlation spectroscopy, whereas hyperpolarization by the K+ ionophore valinomycin increased their mobility. Contrary to this, the mobility of IL-15Rα decreased upon both de- and hyperpolarization. These changes in protein mobility are not due to an alteration of membrane fluidity, as evidenced by fluorescence anisotropy measurements. Förster resonance energy transfer measurements showed that most homo- or heteroassociations of IL-2R, IL-15R, and MHC I did not change considerably, either. MP changes modulated signaling by the two cytokines in distinct ways: depolarization caused a significant increase in the IL-2-induced phosphorylation of signal transducer and activator of transcription 5, whereas hyperpolarization evoked a decrease only in the IL-15-induced signal. Our data imply that the MP may be an important modulator of interleukin receptor signaling and dynamics. Enhanced IL-2 signaling in depolarized Treg cells highly expressing IL-2R may contribute to suppression of antitumor immune surveillance.


Assuntos
Potenciais da Membrana , Receptores de Interleucina-15/metabolismo , Receptores de Interleucina-2/metabolismo , Transdução de Sinais , Linfócitos T/citologia , Linfócitos T/metabolismo , Linhagem Celular Tumoral , Humanos , Fluidez de Membrana , Microambiente Tumoral
9.
Virol J ; 15(1): 43, 2018 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-29530062

RESUMO

BACKGROUND: Toll like receptor (TLR) 3 is a critically important innate pattern recognizing receptor that senses many viral infections. Although, it has been shown that double stranded (ds) RNA can be used for the stimulation of TLR3 signaling pathway in a number of host-viral infection models, it's effectiveness as an antiviral agent against low pathogenic avian influenza virus (LPAIV) needs further investigation. METHODS: In this study, first, we delivered TLR3 ligand, dsRNA, in ovo at embryo day (ED)18 since in ovo route is routinely used for vaccination against poultry viral and parasitic infections and infected with H4N6 LPAIV 24-h post-treatment. A subset of in ovo dsRNA treated and control groups were observed for the expressions of TLR3 and type I interferon (IFN)s, mRNA expression of interleukin (IL)-1ß and macrophage recruitment coinciding with the time of H4N6 LPAIV infection (24 h post-treatment). Additionally, Day 1 chickens were given dsRNA intra-tracheally along with a control group and a subset of chickens were infected with H4N6 LPAIV 24-h post-treatment whereas the rest of the animals were observed for macrophage and type 1 IFN responses coinciding with the time of viral infection. RESULTS: Our results demonstrate that the pre-hatch treatment of eggs with dsRNA reduces H4N6 replication in lungs. Further studies revealed that in ovo delivery of dsRNA increases TLR3 expression, type I IFN production and number of macrophages in addition to mRNA expression of IL-1ß in lung 24-h post-treatment. The same level of induction of innate response was not evident in the spleen. Moreover, we discovered that dsRNA elicits antiviral response against LPAIV correlating with type I IFN activity in macrophages in vitro. Post-hatch, we found no difference in H4N6 LPAIV genome loads between dsRNA treated and control chickens although we observed higher macrophage recruitment and IFN-ß response coinciding with the time of viral infection. CONCLUSIONS: Our findings imply that the TLR3 ligand, dsRNA has antiviral activity in ovo and in vitro but not in chickens post-hatch and dsRNA-mediated innate host response is characterized by macrophage recruitment and expressions of TLR3 and type 1 IFNs.


Assuntos
Imunidade Inata , Vírus da Influenza A/imunologia , Influenza Aviária/imunologia , Influenza Aviária/metabolismo , RNA de Cadeia Dupla/imunologia , Animais , Galinhas , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Influenza Aviária/virologia , Interferon Tipo I/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia , Receptor 3 Toll-Like/metabolismo
10.
J Gen Virol ; 98(6): 1209-1223, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28613150

RESUMO

Cytosine-guanosinedeoxynucleotide (CpG) DNA can be used for the stimulation of the toll-like receptor (TLR)21 signalling pathway in avian species which ultimately leads to up-regulation of gene transcription for pro-inflammatory molecules including nitric oxide and recruitment of innate immune cells. The objective of this study was to determine the antiviral effect of NO, produced in response to in ovo delivery of CpG DNA, against avian influenza virus (AIV) infection. We found that when CpG DNA is delivered at embryo day (ED)18 in ovo and subsequently challenged with H4N6 AIV at ED19 pre-hatch and day 1 post-hatching, CpG DNA reduces H4N6 AIV replication associated with enhanced NO production and macrophage recruitment in lungs. In vitro, we showed that NO originating from macrophages is capable of eliciting an antiviral response against H4N6 AIV infection. This study provides insights into the mechanisms of CpG DNA-mediated antiviral response, particularly against AIV infection in avian species.


Assuntos
DNA/metabolismo , Vírus da Influenza A/imunologia , Influenza Aviária/prevenção & controle , Macrófagos/imunologia , Óxido Nítrico/metabolismo , Receptores Toll-Like/metabolismo , Zigoto/metabolismo , Animais , Embrião de Galinha , Galinhas , Influenza Aviária/imunologia , Transdução de Sinais
12.
J Virol ; 90(8): 3953-3965, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26842471

RESUMO

UNLABELLED: Autographa californicamultiple nucleopolyhedrovirus (AcMNPV) is in the familyBaculoviridae, genusAlphabaculovirus AcMNPVme53is a highly conserved immediate early gene in all lepidopteran baculoviruses that have been sequenced and is transcribed up to late times postinfection. Althoughme53is not essential for viral DNA synthesis, infectious budded virus (BV) production is greatly attenuated when it is deleted. ME53 associates with the nucleocapsid on both budded virus and occlusion-derived virus, but not with the virus envelope. ME53 colocalizes in plasma membrane foci with the envelope glycoprotein GP64 in a GP64-dependent manner. ME53 localizes in the cytoplasm early postinfection, and despite the lack of a reported nuclear localization signal (NLS), ME53 translocates to the nucleus at late times postinfection. To map determinants of ME53 that facilitate its nuclear translocation, recombinant AcMNPV bacmids containing a series of ME53 truncations, internal deletions, and peptides fused with hemagglutinin (HA) or green fluorescent protein (GFP) tags were constructed. Intracellular-localization studies identified residues within amino acids 109 to 137 at the N terminus of ME53 that acted as the nuclear translocation sequence (NTS), facilitating its nuclear transport at late times postinfection. The first 100 N-terminal amino acids and the last 50 C-terminal amino acids of ME53 are dispensable for high levels of budded virus production. The region within amino acids 101 to 398, which also contains the NTS, is critical for optimal levels of budded virus production. IMPORTANCE: Baculovirusme53is a conserved immediate early gene found in all sequenced lepidopteran alpha- and betabaculoviruses. We first identified residues within amino acids 109 to 137 at the N terminus that act as the ME53 nuclear translocation sequence (NTS) to facilitate its nuclear translocation and defined an internal region within amino acids 101 to 398, which includes the NTS, as being necessary for optimal budded virus production. Altogether, these results indicate a previously unidentified nuclear role that ME53 plays in virus replication.


Assuntos
DNA Viral , Proteínas de Ligação a DNA/genética , Sinais de Localização Nuclear , Nucleopoliedrovírus/genética , Proteínas Virais/genética , Replicação Viral , Animais , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Escherichia coli , Genes Virais , Mutagênese Sítio-Dirigida , Spodoptera/virologia , Transfecção , Proteínas Virais/metabolismo
13.
Biochim Biophys Acta Gen Subj ; 1861(11 Pt A): 2619-2629, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28844983

RESUMO

DJ-1 (PARK7) is a multifunctional protein linked to the onset and progression of a number of diseases, most of which are associated with high oxidative stress. The Cys106 of DJ-1 is unusually reactive and thus sensitive to oxidation, and due to high oxidative stress it was observed to be in various oxidized states in disease condition. The oxidation state of Cys106 of DJ-1 is believed to determine the specific functions of the protein in normal and disease conditions. Here we report molecular dynamics simulation and biophysical experimental studies on DJ-1 in reduced (Cys106, S-), oxidized (Cys106, SO2-), and over-oxidized (Cys106, SO3-) states. To simulate the different oxidation states of Cys106 in DJ-1, AMBER related force field parameters were developed and reported for 3-sulfinoalanine and cysteine sulfonic acid. Our studies found that the overall structure of DJ-1 in different oxidation states was similar globally, while it differed locally significantly, which have implications on its stability, function and its link to disease on-set. Importantly, the results suggest that over-oxidation may trigger loss of functions due to local structural modification in the Cys106 containing pocket of DJ-1 and structurally destabilize the dimeric state of DJ-1, which is believed to be its bioactive conformation. Such loss of functions would result in reduced ability of DJ-1 to protect from oxidative stress insults and may lead to increased progression of disease.


Assuntos
Cisteína/metabolismo , Estresse Oxidativo/genética , Conformação Proteica , Proteína Desglicase DJ-1/metabolismo , Fenômenos Biofísicos , Cisteína/genética , Humanos , Simulação de Dinâmica Molecular , Mutação , Oxirredução , Proteína Desglicase DJ-1/química , Proteína Desglicase DJ-1/genética
14.
Vet Res ; 48(1): 63, 2017 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-29017603

RESUMO

Commercial production of swine often involves raising animals in large groups through the use of multi-stage production systems. In such systems, pigs can experience different degrees of contact with animals of the same or different ages. Population size and degree of contact can greatly influence transmission of endemic pathogens, including influenza A virus (IAV). IAV can display high genetic variability, which can further complicate population-level patterns. Yet, the IAV transmission in large multi-site swine production systems has not been well studied. The objectives of this study were to describe the IAV circulation in a multi-source nursery facility and identify factors associated with infection in nursery pigs. Pigs from five sow herds were mixed in one all-in/all-out nursery barn, with 81 and 75 pigs included in two longitudinal studies. Virus isolation was performed in Madin-Darby canine kidney cells and serology was performed using hemagglutination inhibition assays. Risk factor analysis for virological positivity was conducted using logistic regression and stratified Cox's regression for recurrent events. In Study 1, at ≈30 days post-weaning, 100% of pigs were positive, with 43.2% of pigs being positive recurrently over the entire study period. In study 2, 48% of pigs were positive at the peak of the outbreak, and 10.7% were positive recurrently over the entire study period. The results suggest that IAV can circulate during the nursery phase in an endemic pattern and that the likelihood of recurrent infections was associated in a non-linear way with the level of heterologous (within-subtype) maternal immunity (p < 0.05). High within-pen intracluster correlation coefficients (> 0.75) were also observed for the majority of sampling times suggesting that pen-level factors played a role in infection dynamics in this study.


Assuntos
Vírus da Influenza A , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Criação de Animais Domésticos , Animais , Animais Recém-Nascidos/virologia , Cães , Vírus da Influenza A/genética , Estudos Longitudinais , Células Madin Darby de Rim Canino/virologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Fatores de Risco , Suínos , Doenças dos Suínos/transmissão
15.
Comput Inform Nurs ; 35(11): 582-589, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28570286

RESUMO

Intensive care electronic registries have been instrumental in quality measurement, improvement, and assurance of intensive care. In this article, the development and pilot implementation of the Intensive Care Unit Quality Management Registry are described, with a particular focus on monitoring the quality and operational cost in an adult ICU at a northern Greek state hospital. A relational database was developed for a hospital ICU so that qualitative and financial data are recorded for further analysis needed for planning quality care improvement and enhanced efficiency. Key features of this database registry were low development cost, user friendliness, maximum data security, and interoperability in existing hospital information systems. The database included patient demographics, nursing and medical parameters, and quality and performance indicators as established in many national registries worldwide. Cost recording was based on a mixed approach: at patient level ("bottom-up" method) and at department level ("top-down" method). During the pilot phase of the database operation, regular monitoring of quality and cost data revealed several fields of quality excellence, while indicating room for improvement for others. Parallel recording and trending of multiple parameters showed that the database can be utilized for optimum ICU quality and cost management and also for further research purposes by nurses, physicians, and administrators.


Assuntos
Bases de Dados Factuais/estatística & dados numéricos , Hospitais Estaduais , Unidades de Terapia Intensiva/organização & administração , Informática Médica/economia , Sistema de Registros , Bases de Dados Factuais/economia , Grécia , Humanos , Unidades de Terapia Intensiva/normas , Melhoria de Qualidade , Indicadores de Qualidade em Assistência à Saúde/organização & administração , Indicadores de Qualidade em Assistência à Saúde/normas
16.
Can J Microbiol ; 62(12): 993-1002, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27781484

RESUMO

Fowl aviadenoviruses, many of which are of importance in veterinary medicine, are classified into 5 species. In this study, a pathogenic isolate and a nonpathogenic isolate of fowl aviadenovirus serotype 11 (FAdV-11) of species Fowl aviadenovirus D were characterized. Growth rates were analyzed for the 2 isolates, showing notable differences. The complete genomic sequences of the viruses were fully determined and were analyzed. The genomes of the 2 isolates showed 98.1% sequence identity and revealed 6 nonsynonymous mutations between the Ontario isolates. Two of the 6 mutations were also found in the sequences of recently published pathogenic Chinese fowl aviadenovirus 11 isolates, suggesting potential molecular markers that could be associated with pathogenesis. Deletions were found in the L5 region within the overlapping coding sequences for the 100, 22, and 33 kDa proteins, and these were found in only the nonpathogenic isolates. This molecular pattern was identified in FAdV-9, another nonpathogenic FAdV-D species virus. Furthermore, the tandem repeat regions varied dramatically; the pathogenic isolates contained a reduced number of tandem repeats compared with the nonpathogenic isolates. Lastly, a protein produced early in infection was analyzed using bioinformatics to determine its role in disease. This study highlights several candidate molecular determinants of avian adenovirus genomes related to pathogenicity.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/genética , Genoma/genética , Infecções por Adenoviridae/virologia , Sequência de Aminoácidos , Animais , Aviadenovirus/classificação , Aviadenovirus/patogenicidade , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Biologia Computacional , DNA Viral/química , Marcadores Genéticos , Mutação , Filogenia , Aves Domésticas , Alinhamento de Sequência/veterinária , Análise de Sequência de DNA , Sorogrupo , Sequências de Repetição em Tandem
17.
Ideggyogy Sz ; 68(9-10): 339-45, 2015 Sep 30.
Artigo em Húngaro | MEDLINE | ID: mdl-26665496

RESUMO

The classic anterior (frontal) opercular syndrome (Foix-Chavany-Marie sy.) is a cortical pseudobulbar palsy mainly due to bilateral lesions of anterior brain operculum. In 2000 the authors had a 70-year old female patient with acute onset of swallowing and speaking difficulty. Neurological examination established a left facial central palsy, the palsy of the tongue and the soft palate, dysarthry, difficulty in chewing with left side hemiparesis. The CT scan showed a right side (one-sided) frontal opercular ischemic lesion. This event switched their attention especially to this group of cases and subsequently the authors collected 12 patients with these symptoms. Authors discuss the patomechanism of transient pseudobulbar palsy that occurs due to unilateral opercular lesion that the diaschisis effect might explain.


Assuntos
Encéfalo/patologia , Infarto Cerebral/complicações , Infarto Cerebral/diagnóstico , Paralisia Pseudobulbar/diagnóstico , Paralisia Pseudobulbar/etiologia , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/patologia , Infarto Cerebral/fisiopatologia , Transtornos de Deglutição/etiologia , Feminino , Lobo Frontal/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Paralisia Pseudobulbar/diagnóstico por imagem , Paralisia Pseudobulbar/patologia , Paralisia Pseudobulbar/fisiopatologia , Recuperação de Função Fisiológica , Fatores de Risco , Distúrbios da Fala/etiologia , Síndrome , Tomografia Computadorizada por Raios X
18.
Virol J ; 11: 194, 2014 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-25416300

RESUMO

BACKGROUND: Data about molecular diversity of commonly circulating type A influenza viruses in Ontario swine are scarce. Yet, this information is essential for surveillance of animal and public health, vaccine updates, and for understanding virus evolution and its large-scale spread. METHODS: The study population consisted of 21 swine herds with clinical problems due to respiratory disease. Nasal swabs from individual pigs were collected and tested by virus isolation in MDCK cells and by rtRT-PCR. All eight segments of 10 H3N2 viruses were sequenced using high-throughput sequencing and molecularly characterized. RESULTS: Within-herd prevalence ranged between 2 and 100%. Structurally, Ontario H3N2 viruses could be classified into three different groups. Group 1 was the most similar to the original trH3N2 virus from 2005. Group 2 was the most similar to the Ontario turkey H3N2 isolates with PB1 and NS genes originating from trH3N2 virus and M, PB2, PA and NP genes originating from the A(H1N1)pdm09 virus. All Group 3 internal genes were genetically related to A(H1N1)pdm09. Analysis of antigenic sites of HA1 showed that Group 1 had 8 aa changes within 4 antigenic sites, A(1), B(3), C(2) and E(2). The Group 2 viruses had 8 aa changes within 3 antigenic sites A(3), B(3) and C(2), while Group 3 viruses had 4 aa changes within 3 antigenic sites, B(1), D(1) and E(2), when compared to the cluster IV H3N2 virus [A/swine/Ontario/33853/2005/(H3N2)]. CONCLUSIONS: The characterization of the Ontario H3N2 viruses clearly indicates reassortment of gene segments between the North American swine trH3N2 from cluster IV and the A(H1N1)pdm09 virus.


Assuntos
Variação Genética , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Infecções por Orthomyxoviridae/veterinária , RNA Viral/genética , Doenças dos Suínos/virologia , Sequência de Aminoácidos , Animais , Genótipo , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Dados de Sequência Molecular , Ontário , Infecções por Orthomyxoviridae/virologia , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência , Suínos
19.
Virus Genes ; 48(1): 74-80, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24142408

RESUMO

Fowl adenoviruses (FAdVs) are common in broiler operations, and the most frequently isolated FAdVs belong to serotypes 1, 8, and 11. Serotype 1 viruses are considered nonpathogenic. While some serotype 8 and 11 viruses cause inclusion body hepatitis (IBH), these virus serotypes can also be isolated from non-IBH cases. The fiber protein is one of the major constituents of the adenoviral capsid, involved in virus entry, and it has been implicated in the variation of virulence of FAdVs. The fiber gene sequences of four FAdV-8 and four FAdV-11 isolates from both IBH and non-IBH cases were determined and analyzed for a possible association of the fiber gene sequence in virulence. The fiber protein can be divided into tail, shaft, and head domains comprising some specific features. The conserved "RKRP" sequence motif (aa 17-aa 20) fit the consensus sequence predicted for the nuclear localization signal, while the "VYPF" motif (aa 53-aa 56), involved in the penton base interaction, was also found. Similar to mammalian adenoviruses, 17 pseudo-repeats with an average length of 16 aa were detected in the FAdV-8 fiber shaft region, while 20 pseudo-repeats with an average length of 18 aa were found in FAdV-11 fibers. There was a 144-147 nt difference between the fiber genes of the two FAdV serotypes. In the shaft region, the TLWT motif that marks the beginning of the fiber head domain of the mastadenovirus was not evident among examined FAdVs. The FAdV-11 isolates had 99.1 % aa sequence identity and 99.3 % similarity to each other, and there was no conserved aa substitution within the fibers. The FAdV-8 fiber proteins showed an overall lower, 89 % aa sequence identity and 93.4 % similarity, to each other and 22 nonsynonymous mutations were detected. Virulence markers were not detected in the analyzed fiber gene sequences of the different pathotypes of the two FAdV serotypes.


Assuntos
Infecções por Adenoviridae/veterinária , Adenoviridae/classificação , Adenoviridae/genética , Proteínas do Capsídeo/genética , Variação Genética , Adenoviridae/isolamento & purificação , Infecções por Adenoviridae/virologia , Sequência de Aminoácidos , Animais , DNA Viral/química , DNA Viral/genética , Hepatite Viral Animal/virologia , Corpos de Inclusão/virologia , Dados de Sequência Molecular , Aves Domésticas , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
20.
Avian Pathol ; 43(4): 301-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24801979

RESUMO

To investigate the possibility of in ovo infection with avian bornavirus (ABV) in wild Canada geese (Branta canadensis), 53 eggs were opportunistically collected at various stages of embryonic development from 16 free-ranging goose nests at a large urban zoo site where ABV infection is known to be present in this species. ABV RNA was detected in the yolk of one of three unembryonated eggs using real-time reverse transcription polymerase chain reaction. ABV RNA was not identified in the brains from 23 newly hatched goslings or 19 embryos, nor from three early whole embryos. Antibodies against ABV were not detected in the plasma of any of the hatched goslings using an enzyme-linked immunosorbent assay. Possible reasons for the failure to detect ABV RNA in hatchlings or embryos include low sample size, eggs deriving from parents not actively infected with ABV, the testing of only brain tissue, and failure of the virus to replicate in Canada goose embryos. In conclusion, this preliminary investigation demonstrating the presence of ABV RNA in the yolk of a Canada goose egg provides the first evidence for the potential for vertical transmission of ABV in waterfowl.


Assuntos
Doenças das Aves/transmissão , Bornaviridae/isolamento & purificação , Gansos , Transmissão Vertical de Doenças Infecciosas/veterinária , Infecções por Mononegavirales/veterinária , Animais , Doenças das Aves/virologia , Bornaviridae/genética , Infecções por Mononegavirales/transmissão , Infecções por Mononegavirales/virologia , Óvulo/virologia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
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