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1.
Digit Health ; 8: 20552076221097513, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35558638

RESUMO

Objective: Respiratory illnesses have information-rich acoustic biomarkers, such as cough, that can potentially play an important role in screening populations for disease risk. To realize that potential, datasets of paired acoustic-clinical samples are needed for the development and validation of acoustic screening models, and protocols for collecting acoustic samples must be efficient and safe. We collected cough acoustic signatures at a high-throughput SARS-CoV-2 testing site on a college campus. Here, we share logistical details and the dataset of acoustic cough signatures paired with the gold standard in SARS-CoV-2 testing of SARS-CoV-2 genomic sequences using qRT-PCR. Methods: Cough recordings were collected in winter-spring 2021 at a rural residential college (Sewanee, TN, USA), where approximately 2000 students were tested for SARS-CoV-2 on a weekly basis. Cough collection was managed by student volunteers using custom software. Results: 4302 coughs were recorded from 960 participants over 11 weeks. All coughs were COVID-19 negative. Approximately 30 s were required to check-in a participant and collect their cough. Conclusion: The value of acoustic screening tools depends upon our ability to develop and implement them reliably and quickly. For that to happen, high-quality datasets and logistical insights must be collected and shared on an ongoing basis.

2.
Viruses ; 13(12)2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34960622

RESUMO

Hendra virus (HeV) is a zoonotic enveloped member of the family Paramyoxviridae. To successfully infect a host cell, HeV utilizes two surface glycoproteins: the attachment (G) protein to bind, and the trimeric fusion (F) protein to merge the viral envelope with the membrane of the host cell. The transmembrane (TM) region of HeV F has been shown to have roles in F protein stability and the overall trimeric association of F. Previously, alanine scanning mutagenesis has been performed on the C-terminal end of the protein, revealing the importance of ß-branched residues in this region. Additionally, residues S490 and Y498 have been demonstrated to be important for F protein endocytosis, needed for the proteolytic processing of F required for fusion. To complete the analysis of the HeV F TM, we performed alanine scanning mutagenesis to explore the residues in the N-terminus of this region (residues 487-506). In addition to confirming the critical roles for S490 and Y498, we demonstrate that mutations at residues M491 and L492 alter F protein function, suggesting a role for these residues in the fusion process.


Assuntos
Vírus Hendra/genética , Infecções por Henipavirus/virologia , Fusão de Membrana , Proteínas Virais de Fusão/metabolismo , Alanina/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Membrana Celular/metabolismo , Chlorocebus aethiops , Endocitose , Endossomos/metabolismo , Genes Reporter , Vírus Hendra/fisiologia , Humanos , Mutagênese Sítio-Dirigida , Domínios Proteicos , Estabilidade Proteica , Células Vero , Proteínas Virais de Fusão/genética
3.
J Clin Med ; 10(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806626

RESUMO

This article explores the clinical implications of the three different classes drawn from a Rasch analysis of the general movements optimality scores (GMOS) of 383 infants. Parametric analysis of the class membership examines four variables: age of assessment, brain injury presence, general movement patterns, and 2-year-old outcomes. GMOS separated infants with typical (class 3) from atypical development, and further separated cerebral palsy (class 2) from other neurodevelopmental disorders (class 1). Each class is unique regarding its quantitative and qualitative representations on the four variables. The GMOS has strong psychometric properties and provides a quantitative measure of early motor functions. The GMOS can be confidently used to assist with early diagnosis and predict distinct classes of developmental outcomes, grade motor behaviors, and provide a solid base to study individual general movement developmental trajectories.

4.
J Appl Meas ; 21(1): 17-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32129767

RESUMO

AIM: To explore the psychometric properties of the general movements optimality score (GMOS) by examining its dimensionality, rating scale functioning, and item hierarchies using Rasch measurement. METHODS: Secondary data analysis of the GMOS data for video-recording of 383 infants with uni-, multidimensional, and mixed Rasch partial credit models. Videos were scored based on the global General Movement Assessment categories, and on the amplitude, speed, spatial range, proximal and distal rotations, onset and offset, tremulous and cramped components of the upper and lower extremities (21 items), resulting in the GMOS. RESULTS: The GMOS data fits best to a unidimensional mixed Rasch model with three different classes of infants, with all but two items contributing to the infants' separation. Rating scales functioned well for 19 items. Item difficulty hierarchies varied depending on infants' class. No floor effect and no substantive gaps between item difficulty estimates were found. CONCLUSION: The GMOS has strong psychometric properties to distinguish infants with different functional motor performance and provides a quantitative measure of quality of movement. INTERPRETATION: The GMOS can be confidently used to assist with early diagnosis, grade motor performance, and provide a solid base to study individual general movement developmental trajectories.


Assuntos
Movimento , Psicometria , Humanos , Lactente , Modelos Logísticos , Registros , Reprodutibilidade dos Testes , Inquéritos e Questionários
5.
Int J Health Care Qual Assur ; ahead-of-print(ahead-of-print)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32083408

RESUMO

PURPOSE: There is a growing interest in applying continuous quality improvement (CQI) methodologies and tools to medical education contexts. One such tool, the "Are We Making Progress" questionnaire from the Malcolm Baldrige National Quality Award framework, adequately captures the dimensions critical for performance excellence and allows organizations to assess their performance and identify areas for improvement. Its results have been widely validated in business, education, and health care and might be applicable in medical education contexts. The measurement properties of the questionnaire data were analyzed using Rasch modeling to determine if validity evidence, based on Messick's framework, supports the interpretation of results in medical education contexts. Rasch modeling was performed since the questionnaire uses Likert-type scales whose estimates might not be amenable to parametric statistical analyses. DESIGN/METHODOLOGY/APPROACH: Leaders and teachers at 16 of the 17 Canadian medical schools were invited in 2015-2016 to complete the 40-item questionnaire. Data were analyzed using the ConQuest Rasch calibration program, rating scale model. FINDINGS: 491 faculty members from 11 (69 percent) schools participated. A seven-dimensional, four-point response scale model better fit the data. Overall data fit to model requirements supported the use of person measures with parametric statistics. The structural, content, generalizability, and substantive validity evidence supported the interpretation of results in medical education contexts. ORIGINALITY/VALUE: For the first time, the Baldrige questionnaire results were validated in medical education contexts. Medical education leaders are encouraged to serially use this questionnaire to measure progress on their school's CQI focus.


Assuntos
Educação de Graduação em Medicina/normas , Psicometria/instrumentação , Melhoria de Qualidade , Gestão da Qualidade Total , Adulto , Canadá , Docentes de Medicina/psicologia , Humanos , Modelos Teóricos , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Gerontol Geriatr Educ ; 41(4): 480-493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30058943

RESUMO

Interprofessional education (IPE) is critical for ensuring that students are prepared to collaborate with team members across disciplines once they enter clinical practice; particularly, in the complex care of the geriatric population. This qualitative study explored the experiences of interdisciplinary students in a clinical based IPE experience at a senior housing residence. Reflective journals were examined from students (n = 23) in nursing, social work, pharmacy, and medicine participating in an IPE program. Four core themes emerged in the analysis: exposure to geriatrics, IPE advantages for students, IPE advantages for older adults, and IPE challenges. Findings from this study confirmed advantages of IPE in a real-world clinical setting in terms of students learning the value and scope of practice of interdisciplinary team members. The exposure to geriatrics helped students to gain an in-depth understanding of issues affecting older adults in the community and increase professional confidence in their future clinical practice.


Assuntos
Comportamento Cooperativo , Geriatria , Educação Interprofissional , Percepção , Estudantes de Ciências da Saúde , Idoso , Humanos , Aprendizagem , Pesquisa Qualitativa , Instituições Residenciais , Redação
7.
Identity (Mahwah, N J) ; 19(1): 44-61, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31391792

RESUMO

The authors examined the dimensionality and psychometric properties of the Multigroup Ethnic Identity Measure (MEIM) among Black South African adolescents (ages = 13-14; 52% female) representing several ethnic groups (Ndebele, Pedi, Sotho, Swati, Tsonga, Tswana, Venda, Xhosa, Zulu) and evaluated the measure for differential item functioning primarily among four ethnic groups (Sotho, Tswana, Xhosa, and Zulu). Results indicated that a two-dimensional model best represented the data, reflecting ethnic search/clarity and ethnic affirmations. Subsequently, we evaluated the equivalence of the MEIM among the four South African ethnic groups and a sample of African American adolescents (Mage  = 15.57 years; SD = 1.22; 51% female). Further analyses revealed that configural and metric models were excellent across the four South African ethnic groups and the African American group. However, scalar invariance (i.e., intercept) was not found; the item intercepts were different for the South African ethnic groups and African Americans. Findings are discussed with consideration for conducting research on ethnic identity among youth in South Africa.

8.
West J Nurs Res ; 41(2): 258-278, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29808772

RESUMO

The aim of this study was to examine the psychometric properties of the job embeddedness instrument (JEI) using a Rasch perspective in a sample of Registered Nurses (RNs). A secondary analysis of data was conducted from a previous study examining the job embeddedness of rural and urban RNs. A Rasch analysis supported the six underlying dimensions: organizational fit, community fit, organizational links, community links, organizational sacrifice, and community sacrifice. The results of this study also demonstrate additional evidence of the validity, reliability, and generalizability of the JEI inferences with a sample of RNs. In total, 38 of 39 items of the original JEI were retained in the model. The psychometric evaluation attained through this multidimensional Rasch analysis provided support for using the JEI to assess the level of job embeddedness for RNs.


Assuntos
Satisfação no Emprego , Reorganização de Recursos Humanos/estatística & dados numéricos , Psicometria/normas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Meio-Oeste dos Estados Unidos , Lealdade ao Trabalho , Psicometria/instrumentação , Psicometria/métodos , Reprodutibilidade dos Testes , Inquéritos e Questionários
9.
J Appl Meas ; 19(1): 93-105, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29561744

RESUMO

Social perspective-taking (SPT), which involves the ability infer others' intentions, is a consequential social cognitive process. The purpose of this study is to evaluate the psychometric properties of a web-based social perspective-taking (SELweb SPT) assessment designed for children in kindergarten through third grade. Data were collected from two separate samples of children. The first sample included 3224 children and the second sample included 4419 children. Data were calibrated using Rasch dichotomous model (Rasch, 1960). Differential item and test functioning were also evaluated across gender and ethnicity groups. Across both samples, we found: evidence of consistent item fit; unidimensional item structure; and adequate item targeting. Poor item targeting at high and low ability levels suggests that more items are needed to distinguish low and high ability respondents. Analyses of DIF found some significant item-level DIF across gender, but no DIF across ethnicity. The analyses of person measure calibrations with and without DIF items evidenced negligible differential test functioning (DTF) across gender and ethnicity groups in both samples.


Assuntos
Internet , Modelos Estatísticos , Psicometria/métodos , Psicometria/normas , Comportamento Social , Criança , Feminino , Humanos , Masculino , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Inquéritos e Questionários
10.
mBio ; 9(2)2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511076

RESUMO

Emerging coronaviruses (CoVs) cause severe disease in humans, but no approved therapeutics are available. The CoV nsp14 exoribonuclease (ExoN) has complicated development of antiviral nucleosides due to its proofreading activity. We recently reported that the nucleoside analogue GS-5734 (remdesivir) potently inhibits human and zoonotic CoVs in vitro and in a severe acute respiratory syndrome coronavirus (SARS-CoV) mouse model. However, studies with GS-5734 have not reported resistance associated with GS-5734, nor do we understand the action of GS-5734 in wild-type (WT) proofreading CoVs. Here, we show that GS-5734 inhibits murine hepatitis virus (MHV) with similar 50% effective concentration values (EC50) as SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). Passage of WT MHV in the presence of the GS-5734 parent nucleoside selected two mutations in the nsp12 polymerase at residues conserved across all CoVs that conferred up to 5.6-fold resistance to GS-5734, as determined by EC50 The resistant viruses were unable to compete with WT in direct coinfection passage in the absence of GS-5734. Introduction of the MHV resistance mutations into SARS-CoV resulted in the same in vitro resistance phenotype and attenuated SARS-CoV pathogenesis in a mouse model. Finally, we demonstrate that an MHV mutant lacking ExoN proofreading was significantly more sensitive to GS-5734. Combined, the results indicate that GS-5734 interferes with the nsp12 polymerase even in the setting of intact ExoN proofreading activity and that resistance can be overcome with increased, nontoxic concentrations of GS-5734, further supporting the development of GS-5734 as a broad-spectrum therapeutic to protect against contemporary and emerging CoVs.IMPORTANCE Coronaviruses (CoVs) cause severe human infections, but there are no approved antivirals to treat these infections. Development of nucleoside-based therapeutics for CoV infections has been hampered by the presence of a proofreading exoribonuclease. Here, we expand the known efficacy of the nucleotide prodrug remdesivir (GS-5734) to include a group ß-2a CoV. Further, GS-5734 potently inhibits CoVs with intact proofreading. Following selection with the GS-5734 parent nucleoside, 2 amino acid substitutions in the nsp12 polymerase at residues that are identical across CoVs provide low-level resistance to GS-5734. The resistance mutations decrease viral fitness of MHV in vitro and attenuate pathogenesis in a SARS-CoV animal model of infection. Together, these studies define the target of GS-5734 activity and demonstrate that resistance is difficult to select, only partial, and impairs fitness and virulence of MHV and SARS-CoV, supporting further development of GS-5734 as a potential effective pan-CoV antiviral.


Assuntos
Alanina/análogos & derivados , Antivirais/farmacologia , Coronavirus/efeitos dos fármacos , Coronavirus/enzimologia , Exorribonucleases/metabolismo , Ribonucleotídeos/farmacologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Monofosfato de Adenosina/análogos & derivados , Alanina/farmacologia , Animais , Exorribonucleases/química , Exorribonucleases/genética , Camundongos , Mutação/genética , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Replicação Viral/efeitos dos fármacos , Replicação Viral/genética
11.
J Virol ; 92(1)2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29046453

RESUMO

Coronaviruses (CoVs) are positive-sense RNA viruses that infect numerous mammalian and avian species and are capable of causing severe and lethal disease in humans. CoVs encode several innate immune antagonists that counteract the host innate immune response to facilitate efficient viral replication. CoV nonstructural protein 14 (nsp14) encodes 3'-to-5' exoribonuclease activity (ExoN), which performs a proofreading function and is required for high-fidelity replication. Outside of the order Nidovirales, arenaviruses are the only RNA viruses that encode an ExoN, which functions to degrade double-stranded RNA (dsRNA) replication intermediates. In this study, we tested the hypothesis that CoV ExoN also functions to antagonize the innate immune response. We demonstrate that viruses lacking ExoN activity [ExoN(-)] are sensitive to cellular pretreatment with interferon beta (IFN-ß) in a dose-dependent manner. In addition, ExoN(-) virus replication was attenuated in wild-type bone marrow-derived macrophages (BMMs) and partially restored in interferon alpha/beta receptor-deficient (IFNAR-/-) BMMs. ExoN(-) virus replication did not result in IFN-ß gene expression, and in the presence of an IFN-ß-mediated antiviral state, ExoN(-) viral RNA levels were not substantially reduced relative to those of untreated samples. However, ExoN(-) virus generated from IFN-ß-pretreated cells had reduced specific infectivity and decreased relative fitness, suggesting that ExoN(-) virus generated during an antiviral state is less viable to establish a subsequent infection. Overall, our data suggest murine hepatitis virus (MHV) ExoN activity is required for resistance to the innate immune response, and antiviral mechanisms affecting the viral RNA sequence and/or an RNA modification act on viruses lacking ExoN activity.IMPORTANCE CoVs encode multiple antagonists that prevent or disrupt an efficient innate immune response. Additionally, no specific antiviral therapies or vaccines currently exist for human CoV infections. Therefore, the study of CoV innate immune antagonists is essential for understanding how CoVs overcome host defenses and to maximize potential therapeutic interventions. Here, we sought to determine the contributions of nsp14 ExoN activity in the induction of and resistance to the innate immune response. We show that viruses lacking nsp14 ExoN activity are more sensitive than wild-type MHV to restriction by exogenous IFN-ß and that viruses produced in the presence of an antiviral state are less capable of establishing a subsequent viral infection. Our results support the hypothesis that murine hepatitis virus ExoN activity is required for resistance to the innate immune response.


Assuntos
Exorribonucleases/genética , Exorribonucleases/metabolismo , Imunidade Inata , Vírus da Hepatite Murina/enzimologia , Vírus da Hepatite Murina/imunologia , Proteínas não Estruturais Virais/metabolismo , Animais , Antivirais/farmacologia , Genoma Viral , Interferon beta/farmacologia , Camundongos , Vírus da Hepatite Murina/efeitos dos fármacos , Vírus da Hepatite Murina/genética , Mutagênese , Mutação , RNA Viral/metabolismo , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Replicação Viral/efeitos dos fármacos
12.
mBio ; 8(6)2017 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-29114026

RESUMO

The coronavirus (CoV) RNA genome is the largest among the single-stranded positive-sense RNA viruses. CoVs encode a proofreading 3'-to-5' exoribonuclease within nonstructural protein 14 (nsp14-ExoN) that is responsible for CoV high-fidelity replication. Alanine substitution of ExoN catalytic residues [ExoN(-)] in severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and murine hepatitis virus (MHV) disrupts ExoN activity, yielding viable mutant viruses with defective replication, up to 20-fold-decreased fidelity, and increased susceptibility to nucleoside analogues. To test the stability of the ExoN(-) genotype and phenotype, we passaged MHV-ExoN(-) 250 times in cultured cells (P250), in parallel with wild-type MHV (WT-MHV). Compared to MHV-ExoN(-) P3, MHV-ExoN(-) P250 demonstrated enhanced replication and increased competitive fitness without reversion at the ExoN(-) active site. Furthermore, MHV-ExoN(-) P250 was less susceptible than MHV-ExoN(-) P3 to multiple nucleoside analogues, suggesting that MHV-ExoN(-) was under selection for increased replication fidelity. We subsequently identified novel amino acid changes within the RNA-dependent RNA polymerase and nsp14 of MHV-ExoN(-) P250 that partially accounted for the reduced susceptibility to nucleoside analogues. Our results suggest that increased replication fidelity is selected in ExoN(-) CoVs and that there may be a significant barrier to ExoN(-) reversion. These results also support the hypothesis that high-fidelity replication is linked to CoV fitness and indicate that multiple replicase proteins could compensate for ExoN functions during replication.IMPORTANCE Uniquely among RNA viruses, CoVs encode a proofreading exoribonuclease (ExoN) in nsp14 that mediates high-fidelity RNA genome replication. Proofreading-deficient CoVs with disrupted ExoN activity [ExoN(-)] either are nonviable or have significant defects in replication, RNA synthesis, fidelity, fitness, and virulence. In this study, we showed that ExoN(-) murine hepatitis virus can adapt during long-term passage for increased replication and fitness without reverting the ExoN-inactivating mutations. Passage-adapted ExoN(-) mutants also demonstrate increasing resistance to nucleoside analogues that is explained only partially by secondary mutations in nsp12 and nsp14. These data suggest that enhanced resistance to nucleoside analogues is mediated by the interplay of multiple replicase proteins and support the proposed link between CoV fidelity and fitness.


Assuntos
Coronavirus/enzimologia , Coronavirus/genética , Exorribonucleases/genética , Aptidão Genética , Mutação , Animais , Antivirais/farmacologia , Azacitidina/farmacologia , Linhagem Celular , Coronavirus/efeitos dos fármacos , Coronavirus/patogenicidade , Infecções por Coronavirus/virologia , Exorribonucleases/metabolismo , Genoma Viral , Genótipo , Camundongos , Fenótipo , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Ribavirina/farmacologia , Replicação Viral/genética
14.
mBio ; 8(1)2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28143984

RESUMO

Coronavirus (CoV) replication and transcription are carried out in close proximity to restructured endoplasmic reticulum (ER) membranes in replication/transcription complexes (RTC). Many of the CoV nonstructural proteins (nsps) are required for RTC function; however, not all of their functions are known. nsp15 contains an endoribonuclease domain that is conserved in the CoV family. While the enzymatic activity and crystal structure of nsp15 are well defined, its role in replication remains elusive. nsp15 localizes to sites of RNA replication, but whether it acts independently or requires additional interactions for its function remains unknown. To begin to address these questions, we created an in situ tagged form of nsp15 using the prototypic CoV, mouse hepatitis virus (MHV). In MHV, nsp15 contains the genomic RNA packaging signal (P/S), a 95-bp RNA stem-loop structure that is not required for viral replication or nsp15 function. Utilizing this knowledge, we constructed an internal hemagglutinin (HA) tag that replaced the P/S. We found that nsp15-HA was localized to discrete perinuclear puncta and strongly colocalized with nsp8 and nsp12, both well-defined members of the RTC, but not the membrane (M) protein, involved in virus assembly. Finally, we found that nsp15 interacted with RTC-associated proteins nsp8 and nsp12 during infection, and this interaction was RNA independent. From this, we conclude that nsp15 localizes and interacts with CoV proteins in the RTC, suggesting it plays a direct or indirect role in virus replication. Furthermore, the use of in situ epitope tags could be used to determine novel nsp-nsp interactions in coronaviruses. IMPORTANCE: Despite structural and biochemical data demonstrating that the coronavirus nsp15 protein contains an endoribonuclease domain, its precise function during coronavirus infection remains unknown. In this work, we created a novel in situ tagged form of nsp15 to study interactions and localization during infection. This in situ tag was tolerated by MHV and did not affect viral replication. Utilizing this tag, we established that nsp15 localized to sites of replication but not sites of assembly throughout infection. Furthermore, we found that nsp15 interacted with the putative viral primase nsp8 and polymerase nsp12 during CoV infection. The strong association of nsp15 with replication complexes and interactions with replicative CoV enzymes suggest nsp15 is involved in CoV replication. These data and tools developed in this study help elucidate the function of nsp15 during infection and may be used to uncover other novel viral protein interactions.


Assuntos
Vírus da Hepatite Murina/fisiologia , Multimerização Proteica , Transcrição Gênica , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Animais , Linhagem Celular , Humanos , Vírus da Hepatite Murina/genética , Ligação Proteica
15.
J Virol ; 90(21): 9683-9692, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27535047

RESUMO

RNA viruses present an extraordinary threat to human health, given their sudden and unpredictable appearance, the potential for rapid spread among the human population, and their ability to evolve resistance to antiviral therapies. The recent emergence of chikungunya virus, Zika virus, and Ebola virus highlights the struggles to contain outbreaks. A significant hurdle is the availability of antivirals to treat the infected or protect at-risk populations. While several compounds show promise in vitro and in vivo, these outbreaks underscore the need to accelerate drug discovery. The replication of several viruses has been described to rely on host polyamines, small and abundant positively charged molecules found in the cell. Here, we describe the antiviral effects of two molecules that alter polyamine levels: difluoromethylornithine (DFMO; also called eflornithine), which is a suicide inhibitor of ornithine decarboxylase 1 (ODC1), and diethylnorspermine (DENSpm), an activator of spermidine/spermine N1-acetyltransferase (SAT1). We show that reducing polyamine levels has a negative effect on diverse RNA viruses, including several viruses involved in recent outbreaks, in vitro and in vivo These findings highlight the importance of the polyamine biosynthetic pathway to viral replication, as well as its potential as a target in the development of further antivirals or currently available molecules, such as DFMO. IMPORTANCE: RNA viruses present a significant hazard to human health, and combatting these viruses requires the exploration of new avenues for targeting viral replication. Polyamines, small positively charged molecules within the cell, have been demonstrated to facilitate infection for a few different viruses. Our study demonstrates that diverse RNA viruses rely on the polyamine pathway for replication and highlights polyamine biosynthesis as a promising drug target.


Assuntos
Antivirais/farmacologia , Poliaminas/metabolismo , Vírus de RNA/efeitos dos fármacos , Acetiltransferases/metabolismo , Animais , Linhagem Celular , Febre de Chikungunya/tratamento farmacológico , Febre de Chikungunya/virologia , Vírus Chikungunya/efeitos dos fármacos , Vírus Chikungunya/metabolismo , Surtos de Doenças , Ebolavirus/efeitos dos fármacos , Ebolavirus/metabolismo , Eflornitina/farmacologia , Doença pelo Vírus Ebola/tratamento farmacológico , Doença pelo Vírus Ebola/virologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Espermina/análogos & derivados , Espermina/farmacologia , Replicação Viral/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Infecção por Zika virus/tratamento farmacológico , Infecção por Zika virus/virologia
16.
J Virol ; 90(16): 7415-7428, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27279608

RESUMO

UNLABELLED: Positive-sense RNA viruses encode RNA-dependent RNA polymerases (RdRps) essential for genomic replication. With the exception of the large nidoviruses, such as coronaviruses (CoVs), RNA viruses lack proofreading and thus are dependent on RdRps to control nucleotide selectivity and fidelity. CoVs encode a proofreading exonuclease in nonstructural protein 14 (nsp14-ExoN), which confers a greater-than-10-fold increase in fidelity compared to other RNA viruses. It is unknown to what extent the CoV polymerase (nsp12-RdRp) participates in replication fidelity. We sought to determine whether homology modeling could identify putative determinants of nucleotide selectivity and fidelity in CoV RdRps. We modeled the CoV murine hepatitis virus (MHV) nsp12-RdRp structure and superimposed it on solved picornaviral RdRp structures. Fidelity-altering mutations previously identified in coxsackie virus B3 (CVB3) were mapped onto the nsp12-RdRp model structure and then engineered into the MHV genome with [nsp14-ExoN(+)] or without [nsp14-ExoN(-)] ExoN activity. Using this method, we identified two mutations conferring resistance to the mutagen 5-fluorouracil (5-FU): nsp12-M611F and nsp12-V553I. For nsp12-V553I, we also demonstrate resistance to the mutagen 5-azacytidine (5-AZC) and decreased accumulation of mutations. Resistance to 5-FU, and a decreased number of genomic mutations, was effectively masked by nsp14-ExoN proofreading activity. These results indicate that nsp12-RdRp likely functions in fidelity regulation and that, despite low sequence conservation, some determinants of RdRp nucleotide selectivity are conserved across RNA viruses. The results also indicate that, with regard to nucleotide selectivity, nsp14-ExoN is epistatic to nsp12-RdRp, consistent with its proposed role in a multiprotein replicase-proofreading complex. IMPORTANCE: RNA viruses have evolutionarily fine-tuned replication fidelity to balance requirements for genetic stability and diversity. Responsibility for replication fidelity in RNA viruses has been attributed to the RNA-dependent RNA polymerases, with mutations in RdRps for multiple RNA viruses shown to alter fidelity and attenuate virus replication and virulence. Coronaviruses (CoVs) are the only known RNA viruses to encode a proofreading exonuclease (nsp14-ExoN), as well as other replicase proteins involved in regulation of fidelity. This report shows that the CoV RdRp (nsp12) likely functions in replication fidelity; that residue determinants of CoV RdRp nucleotide selectivity map to similar structural regions of other, unrelated RNA viral polymerases; and that for CoVs, the proofreading activity of the nsp14-ExoN is epistatic to the function of the RdRp in fidelity.


Assuntos
Vírus da Hepatite Murina/enzimologia , Mutagênicos/metabolismo , Mutação , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Modelos Moleculares , Conformação Molecular , Vírus da Hepatite Murina/efeitos dos fármacos , Vírus da Hepatite Murina/genética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Picornaviridae/enzimologia , RNA Polimerase Dependente de RNA/química , Genética Reversa
17.
Bone ; 85: 115-22, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26855374

RESUMO

Increased bone formation resulting from mechanical loading is well documented; however, the interactions of the mechanotransduction pathways are less well understood. Endothelin-1, a ubiquitous autocrine/paracrine signaling molecule promotes osteogenesis in metastatic disease. In the present study, it was hypothesized that exposure to big endothelin-1 (big ET1) and/or mechanical loading would promote osteogenesis in ex vivo trabecular bone cores. In a 2×2 factorial trial of daily mechanical loading (-2000µÎµ, 120cycles daily, "jump" waveform) and big ET1 (25ng/mL), 48 bovine sternal trabecular bone cores were maintained in bioreactor chambers for 23days. The bone cores' response to the treatment stimuli was assessed with percent change in core apparent elastic modulus (ΔEapp), static and dynamic histomorphometry, and prostaglandin E2 (PGE2) secretion. Two-way ANOVA with a post hoc Fisher's LSD test found no significant treatment effects on ΔEapp (p=0.25 and 0.51 for load and big ET1, respectively). The ΔEapp in the "no load + big ET1" (CE, 13±12.2%, p=0.56), "load + no big ET1" (LC, 17±3.9%, p=0.14) and "load + big ET1" (LE, 19±4.2%, p=0.13) treatment groups were not statistically different than the control group (CC, 3.3%±8.6%). Mineralizing surface (MS/BS), mineral apposition (MAR) and bone formation rates (BFR/BS) were significantly greater in LE than CC (p=0.037, 0.0040 and 0.019, respectively). While the histological bone formation markers in LC trended to be greater than CC (p=0.055, 0.11 and 0.074, respectively) there was no difference between CE and CC (p=0.61, 0.50 and 0.72, respectively). Cores in LE and LC had more than 50% greater MS/BS (p=0.037, p=0.055 respectively) and MAR (p=0.0040, p=0.11 respectively) than CC. The BFR/BS was more than two times greater in LE (p=0.019) and LC (p=0.074) than CC. The PGE2 levels were elevated at 8days post-osteotomy in all groups and the treatment groups remained elevated compared to the CC group on days 15, 19 and 23. The data suggest that combined exposure to big ET1 and mechanical loading results in increased osteogenesis as measured in biomechanical, histomorphometric and biochemical responses.


Assuntos
Endotelina-1/farmacologia , Osteogênese/efeitos dos fármacos , Esterno/fisiologia , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Bovinos , Meios de Cultura , Dinoprostona/metabolismo , Módulo de Elasticidade/efeitos dos fármacos , Esterno/efeitos dos fármacos , Suporte de Carga/fisiologia
18.
Cannabis Cannabinoid Res ; 1(1): 252-261, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28861497

RESUMO

Introduction: Rates of cannabis use disorder (CUD) among vulnerable populations have increased in recent years, highlighting a need to equip providers with an efficient screening tool. Materials and Methods: A short form of the Cannabis Use Disorder Identification Test-Revised (CUDIT-R) was developed by using item response theory and traditional statistical methods, with data from two community samples of cannabis users representing two countries. Four item selection methods (Rasch regression, test characteristic curve, logistic regression, discriminant function analysis) were employed to identify the optimal three-item shortened version. The diagnostic ability of the short form was evaluated by using receiver operating characteristic curves. Results: Using a cut score of 2, the 3-item CUDIT-Short Form (CUDIT-SF; reliability alpha=0.66, Sample 1; 0.80, Sample 2) identified 78.26% of participants in Sample 1 and 78.31% of participants in Sample 2 who met DSM-5 criteria for CUD, with 98% agreement in Sample 1 and 93% agreement in Sample 2 with the full CUDIT-R on CUD classifications using a cut score of 13. Specificity was 76.70 and 78.00 in Samples 1 and 2, respectively. Conclusions: The CUDIT-SF may be useful in busy clinical settings for a stepwise screening. Further validation of this shortened version with larger samples and in different settings is warranted.

19.
Pediatr Phys Ther ; 27(4): 337-48, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26397075

RESUMO

PURPOSE: The Pediatric Balance Scale (PBS) is a 14-item measure of functional balance for children. This study examined PBS dimensionality, rating scale function, and hierarchical properties using Rasch analysis. METHODS: The PBS data were analyzed retrospectively for 823 children, aged 2 to 13 years, with uni- and multidimensional Rasch partial credit models. RESULTS: The PBS best fits a unidimensional model based on the Bayesian information criterion analysis (12,400.73 vs 12,404.48), strong correlations between 3 proposed dimensions (r = 0.946-0.979), and high internal consistency (Cronbach α = 0.94). Analysis of rating scale functioning is limited by small numbers of children achieving low scores on easy items. Item maps indicated a ceiling effect but no substantive gaps between item difficulty estimates. CONCLUSION: The PBS items are best targeted to preschool-age children; additional children with known balance dysfunction are required to fully assess functioning of the easiest PBS items. Revisions may improve PBS utility in older children.


Assuntos
Deficiências do Desenvolvimento/reabilitação , Modalidades de Fisioterapia , Psicometria/métodos , Fatores Etários , Teorema de Bayes , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Equilíbrio Postural , Reprodutibilidade dos Testes , Estudos Retrospectivos
20.
J Virol ; 89(17): 8701-12, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26109733

RESUMO

UNLABELLED: Mammalian orthoreoviruses (reoviruses) are nonenveloped double-stranded RNA viruses that infect most mammalian species, including humans. Reovirus binds to cell surface glycans, junctional adhesion molecule A (JAM-A), and the Nogo-1 receptor (depending on the cell type) and enters cells by receptor-mediated endocytosis. Within the endocytic compartment, reovirus undergoes stepwise disassembly, which is followed by release of the transcriptionally active viral core into the cytoplasm. In a small-molecule screen to identify host mediators of reovirus infection, we found that treatment of cells with 5-nonyloxytryptamine (5-NT), a prototype serotonin receptor agonist, diminished reovirus cytotoxicity. 5-NT also blocked reovirus infection. In contrast, treatment of cells with methiothepin mesylate, a serotonin antagonist, enhanced infection by reovirus. 5-NT did not alter cell surface expression of JAM-A or attachment of reovirus to cells. However, 5-NT altered the distribution of early endosomes with a concomitant impairment of reovirus transit to late endosomes and a delay in reovirus disassembly. Consistent with an inhibition of viral disassembly, 5-NT treatment did not alter infection by in vitro-generated infectious subvirion particles, which bind to JAM-A but bypass a requirement for proteolytic uncoating in endosomes to infect cells. We also found that treatment of cells with 5-NT decreased the infectivity of alphavirus chikungunya virus and coronavirus mouse hepatitis virus. These data suggest that serotonin receptor signaling influences cellular activities that regulate entry of diverse virus families and provides a new, potentially broad-spectrum target for antiviral drug development. IMPORTANCE: Identification of well-characterized small molecules that modulate viral infection can accelerate development of antiviral therapeutics while also providing new tools to increase our understanding of the cellular processes that underlie virus-mediated cell injury. We conducted a small-molecule screen to identify compounds capable of inhibiting cytotoxicity caused by reovirus, a prototype double-stranded RNA virus. We found that 5-nonyloxytryptamine (5-NT) impairs reovirus infection by altering viral transport during cell entry. Remarkably, 5-NT also inhibits infection by an alphavirus and a coronavirus. The antiviral properties of 5-NT suggest that serotonin receptor signaling is an important regulator of infection by diverse virus families and illuminate a potential new drug target.


Assuntos
Infecções por Reoviridae/tratamento farmacológico , Reoviridae/patogenicidade , Antagonistas da Serotonina/farmacologia , Triptaminas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Animais , Antivirais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Vírus Chikungunya/efeitos dos fármacos , Vírus Chikungunya/patogenicidade , Chlorocebus aethiops , Toxina da Cólera/metabolismo , Cricetinae , Citoesqueleto/efeitos dos fármacos , Endossomos/fisiologia , Endossomos/virologia , Células HeLa , Humanos , Interferon gama/biossíntese , Células L , Metiotepina/farmacologia , Camundongos , Vírus da Hepatite Murina/efeitos dos fármacos , Vírus da Hepatite Murina/patogenicidade , Reoviridae/efeitos dos fármacos , Reoviridae/fisiologia , Transferrina/metabolismo , Células Vero , Montagem de Vírus/efeitos dos fármacos , Ligação Viral/efeitos dos fármacos
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