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1.
Nano Lett ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950351

RESUMO

Layered lithiated oxides are promising materials for next generation Li-ion battery cathode materials; however, instability during cycling results in poor performance over time compared to the high capacities theoretically possible with these materials. Here we report the characterizations of a Li1.47Mn0.57Al0.13Fe0.095Co0.105Ni0.095O2.49 high-entropy layered oxide (HELO) with the Li2MO3 structure where M = Mn, Al, Fe, Co, and Ni. Using electron microscopy and X-ray spectroscopy, we identify a homogeneous Li2MO3 structure stabilized by the entropic contribution of oxygen vacancies. This defect-driven entropy would not be attainable in the LiMO2 structure sometimes observed in similar materials as a secondary phase owing to the presence of fewer O sites and a 3+ oxidation state for the metal site; instead, a Li2-γMO3-δ is produced. Beyond Li2MO3, this defect-driven entropy approach to stabilizing novel compositions and phases can be applied to a wide array of future cathode materials including spinel and rock salt structures.

2.
J Med Virol ; 93(7): 4488-4495, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33768594

RESUMO

To describe the factors associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in mild-to-moderate patients attending for assessment. This observational study was conducted in a Model 4 tertiary referral center in Ireland. All patients referred for SARS-CoV-2 assessment over a 4-week period were included. Patient demographics, presenting symptoms, comorbidities, medications, and outcomes (including length of stay, discharge, and mortality) were collected. Two hundred and seventy-nine patients were assessed. These patients were predominantly female (62%) with a median age of 50 years (SD 16.9). Nineteen (6.8%) patients had SARS-CoV-2 detected. Dysgeusia was associated with a 16-fold increased prediction of SARS-CoV-2 positivity (p = .001; OR, 16.8; 95% CI, 3.82-73.84). Thirteen patients with SARS-COV-2 detected (68.4%) were admitted, in contrast with 38.1% (99/260) of patients with SARS-CoV-2 non-detectable or not tested (p = .001). Female patients were more likely to be hospitalized (p = .01) as were current and ex-smokers (p = .05). We describe olfactory disturbance and fever as the main presenting features in SARS-CoV-2 infection. These patients are more likely to be hospitalized with increased length of stay; however, they make up a minority of the patients assessed. "Non-detectable" patients remain likely to require prolonged hospitalization. Knowledge of predictors of hospitalization in a "non-detectable" cohort will aid future planning and discussion of patient assessment in a SARS-CoV-2 era.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/patologia , Feminino , Hospitalização , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/isolamento & purificação , Fatores Sexuais , Centros de Atenção Terciária
3.
Stroke ; 50(7): 1766-1773, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31167623

RESUMO

Background and Purpose- Plaque inflammation contributes to stroke and coronary events. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) identifies plaque inflammation-related metabolism. Almost no prospective data exist on the relationship of carotid 18F-FDG uptake and early recurrent stroke. Methods- We did a multicenter prospective cohort study BIOVASC (Biomarkers/Imaging Vulnerable Atherosclerosis in Symptomatic Carotid disease) of patients with carotid stenosis and recent stroke/transient ischemic attack with 90-day follow-up. On coregistered carotid 18F-FDG PET/computed tomography angiography, 18F-FDG uptake was expressed as maximum standardized uptake value (SUVmax) in the axial single hottest slice. We then conducted a systematic review of similar studies and pooled unpublished individual-patient data with 2 highly similar independent studies (Dublin and Barcelona). We analyzed the association of SUVmax with all recurrent nonprocedural stroke (before and after PET) and with recurrent stroke after PET only. Results- In BIOVASC (n=109, 14 recurrent strokes), after adjustment (for age, sex, stenosis severity, antiplatelets, statins, diabetes mellitus, hypertension, and smoking), the hazard ratio for recurrent stroke per 1 g/mL SUVmax was 2.2 (CI, 1.1-4.5; P=0.025). Findings were consistent in the independent Dublin (n=52, hazard ratio, 2.2; CI, 1.1-4.3) and Barcelona studies (n=35, hazard ratio, 2.8; CI, 0.98-5.5). In the pooled cohort (n=196), 37 recurrent strokes occurred (29 before and 8 after PET). Plaque SUVmax was higher in patients with all recurrence ( P<0.0001) and post-PET recurrence ( P=0.009). The fully adjusted hazard ratio of any recurrent stroke was 2.19 (CI, 1.41-3.39; P<0.001) and for post-PET recurrent stroke was 4.57 (CI, 1.5-13.96; P=0.008). Recurrent stroke risk increased across SUVmax quartiles (log-rank P=0.003). The area under receiver operating curve for all recurrence was 0.70 (CI, 0.59-0.78) and for post-PET recurrence was 0.80 (CI, 0.64-0.96). Conclusions- Plaque inflammation-related 18F-FDG uptake independently predicted future recurrent stroke post-PET. Although further studies are needed, 18F-FDG PET may improve patient selection for carotid revascularization and suggest that anti-inflammatory agents may have benefit for poststroke vascular prevention.


Assuntos
Estenose das Carótidas , Fluordesoxiglucose F18/administração & dosagem , Placa Aterosclerótica , Tomografia por Emissão de Pósitrons , Acidente Vascular Cerebral , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/epidemiologia , Feminino , Seguimentos , Humanos , Inflamação/complicações , Inflamação/diagnóstico por imagem , Inflamação/epidemiologia , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/complicações , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/epidemiologia , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia
4.
Evol Appl ; 17(2): e13640, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38333553

RESUMO

Evaluating salmon hatchery supplementation programs requires assessing not only program objectives but identifying potential risks to wild populations as well. Such evaluations can be hampered by difficulty in distinguishing between hatchery- and wild-born returning adults. Here, we conducted 3 years (2011-2013) of experimental hatchery supplementation of sockeye salmon in Auke Lake, Juneau, Alaska where a permanent weir allows sampling and genotyping of every returning adult (2008-2019). We identified both hatchery- and wild-born returning adults with parentage assignment, quantified the productivity (adult offspring/spawner) of hatchery spawners relative to that of wild spawners, and compared run timing, age, and size at age between hatchery- and wild-born adults. Hatchery-spawning females produced from approximately six to 50 times more returning adults than did naturally spawning females. Supplementation had no discernable effect on run timing and limited consequences for size at age, but we observed a distinct shift to younger age at maturity in the hatchery-born individuals in all three brood years. The shift appeared to be driven by hatchery-born fish being more likely to emigrate after one, rather than two, years in the lake but the cause is unknown. In cases when spawning or incubation habitat is limiting sockeye salmon production, hatchery supplementation can be effective for enhancing the number of returning adult fish but not without the risk of phenotypic change in the recipient population, which can be an undesired outcome of hatchery supplementation. This study adds to a growing body of evidence suggesting that phenotypic change within a single generation of captive spawning might be widespread in salmon hatchery programs.

5.
J Neurol Neurosurg Psychiatry ; 84(3): 271-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23178505

RESUMO

BACKGROUND: Increasing age is the single largest non-modifiable risk factor for ischaemic stroke. Animal models have substantiated the view that age related neuron vulnerability to ischaemia plays a role in stroke and other age related neurological diseases. Given the key role of the ischaemic penumbra in stroke pathophysiology, we hypothesised that age has an impact on penumbral tissue and its acute determinants. METHODS: We studied a prospective cohort of patients (n=39) at a mean time of 154.7 min from stroke onset, using state of the art whole brain perfusion CT and CT angiography. Penumbral and core were defined using quantitative voxel based thresholds for mean transit time and cerebral blood volume (CBV). Collateral vessel scores were assessed and haemodynamic variables (ie, cerebral blood flow and CBV) were measured in affected and unaffected tissues. RESULTS: While age correlated negatively with normalised penumbral volume (Kendall's τ b=-0.234, p=0.048) and lesion volume (Kendall's τ b=0.238, p=0.045), core volume remained unchanged, accompanied by an incremental collateral response with age (Kendall's τ b=0.496, p<0.0001). Haemodynamic variables remained unaffected by age in our cohort. CONCLUSIONS: These findings, described for the first time in a clinical cohort using whole brain CT perfusion and concomitant vascular imaging, suggest that age has a differential effect on acute tissue compartments in the wake of a preserved collateral vascular response and haemodynamic parameters. In agreement with the preclinical literature, the results point to a distinct tissue response to acute ischaemia in the ageing brain and merit validation studies in larger cohorts, particularly in relation to clinical outcomes.


Assuntos
Isquemia Encefálica/fisiopatologia , Circulação Colateral/fisiologia , Hemodinâmica/fisiologia , Meninges/fisiopatologia , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Volume Sanguíneo , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/patologia , Angiografia Cerebral/métodos , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Masculino , Meninges/diagnóstico por imagem , Pessoa de Meia-Idade , Projetos Piloto , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
6.
BMJ Open ; 12(8): e056182, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35985777

RESUMO

OBJECTIVES: Multifactorial interventions, which involve assessing an individual's risk of falling and providing treatment or onward referral, require coordination across settings. Using a mixed-methods design, we aimed to develop a process map to examine onward referral pathways following falls risk assessment in primary care. SETTING: Primary care fall risk assessment clinics in the South of Ireland. PARTICIPANTS: Focus groups using participatory mapping techniques with primary care staff (public health nurses (PHNs), physiotherapists (PT),and occupational therapists (OT)) were conducted to plot the processes and onward referral pathways at each clinic (n=5). METHODS: Focus groups were analysed in NVivo V.12 using inductive thematic analysis. Routine administrative data from January to March 2018 included details of client referrals, assessments and demographics sourced from referral and assessment forms. Data were analysed in Stata V.12 to estimate the number, origin and focus of onward referrals and whether older adults received follow-up interventions. Quantitative and qualitative data were analysed separately and integrated to produce a map of the service. RESULTS: Nine staff participated in three focus groups and one interview (PHN n=2; OT n=4; PT n=3). 85 assessments were completed at five clinics (female n=69, 81.2%, average age 77). The average number of risk factors was 5.4 out of a maximum of 10. Following assessment, clients received an average of three onward referrals. Only one-third of referrals (n=135/201, 33%) had data available on intervention receipt. Primary care staff identified variations in how formally onward referrals were managed and barriers, including a lack of client information, inappropriate referral and a lack of data management support. CONCLUSION: Challenges to onward referral manifest early in an integrated care pathway, such as clients with multiple risk factors sent for initial assessment and the lack of an integrated IT system to share information across settings.


Assuntos
Acidentes por Quedas , Fisioterapeutas , Acidentes por Quedas/prevenção & controle , Idoso , Feminino , Grupos Focais , Humanos , Terapeutas Ocupacionais , Encaminhamento e Consulta
7.
Cureus ; 13(2): e13280, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33728213

RESUMO

We present a case of an iris sphincter tear with iridodialysis, mydriasis, and hyphema secondary to a traumatic injury from a bungee cord. The correlation between the mechanism of injury and physical exam findings as well as the emergency department evaluation and management are discussed.

8.
BMJ Open ; 10(2): e033069, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32075829

RESUMO

OBJECTIVES: Multifactorial falls risk assessments reduce the rate of falls in older people and are recommended by international guidelines. Despite their effectiveness, their potential impact is often constrained by barriers to implementation. Attendance is an issue. The aim of this study was to explore why older people attend community-based multifactorial falls risk assessment clinics, and to map these reasons to a theoretical framework. DESIGN: This is a qualitative study. Semi-structured interviews were conducted and analysed thematically. Each theme and subtheme were then mapped onto the Theoretical Domains Framework (TDF) to identify the determinants of behaviour. PARTICIPANTS: Older adults (aged 60 and over) who attended community-based multifactorial falls risk assessments. RESULTS: Sixteen interviews were conducted. Three main themes explained participants' reasons for attending the multifactorial risk assessment; being that 'type of person', being 'linked in' with health and community services and having 'strong social support'. Six other themes were identified, but these themes were not as prominent during interviews. These were knowing what to expect, being physically able, having confidence in and being positive towards health services, imagining the benefits given previous positive experiences, determination to maintain or regain independence, and being 'crippled' by the fear of falling. These themes mapped on to nine TDF domains: 'knowledge', 'skills', 'social role and identity', 'optimism', 'beliefs about consequences', 'goals', 'environmental context and resources', 'social influences' and 'emotion'. There were five TDF domains that were not relevant to the reasons for attending. CONCLUSIONS: These findings provide theoretically based factors that influence attendance which can be used to inform the development of interventions to improve attendance to falls prevention programmes.


Assuntos
Acidentes por Quedas/prevenção & controle , Avaliação Geriátrica , Conhecimentos, Atitudes e Prática em Saúde , Serviços de Saúde para Idosos , Motivação , Aceitação pelo Paciente de Cuidados de Saúde , Idoso , Idoso de 80 Anos ou mais , Medo , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Personalidade , Pesquisa Qualitativa , Medição de Risco , Apoio Social
9.
Curr Psychiatry Rep ; 10(1): 37-43, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18269893

RESUMO

Inappropriate prescribing in older people is a common condition associated with significant morbidity, mortality, and financial costs. Medication use increases with age, and this, in conjunction with an increasing disease burden, is associated with adverse drug reactions. This review outlines why older people are more likely to develop adverse drug reactions and how common the problem is. The use of different tools to identify and measure the problem is reviewed. Common syndromes seen in older adults (eg, falling, cognitive impairment, sleep disturbance) are considered, and recent evidence in relation to medication use for these conditions is reviewed. Finally, we present a brief summary of significant developments in the recent literature for those caring for older people.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Acidentes por Quedas , Idoso , Anti-Inflamatórios não Esteroides/efeitos adversos , Biotransformação/fisiologia , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/tratamento farmacológico , Relação Dose-Resposta a Droga , Interações Medicamentosas , Quimioterapia Combinada , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Hipoglicemiantes/efeitos adversos , Limitação da Mobilidade , Farmacocinética , Psicotrópicos/efeitos adversos , Fatores de Risco , Rosiglitazona , Transtornos do Sono-Vigília/induzido quimicamente , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/tratamento farmacológico , Tiazolidinedionas/efeitos adversos , Resultado do Tratamento
10.
Mol Ecol Resour ; 15(5): 1020-30, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25913195

RESUMO

We show that the algorithm in the program flock (Duchesne & Turgeon 2009) can be interpreted as an estimation procedure based on a model essentially identical to the structure (Pritchard et al. 2000) model with no admixture and without correlated allele frequency priors. Rather than using MCMC, the flock algorithm searches for the maximum a posteriori estimate of this structure model via a simulated annealing algorithm with a rapid cooling schedule (namely, the exponent on the objective function →∞). We demonstrate the similarities between the two programs in a two-step approach. First, to enable rapid batch processing of many simulated data sets, we modified the source code of structure to use the flock algorithm, producing the program flockture. With simulated data, we confirmed that results obtained with flock and flockture are very similar (though flockture is some 200 times faster). Second, we simulated multiple large data sets under varying levels of population differentiation for both microsatellite and SNP genotypes. We analysed them with flockture and structure and assessed each program on its ability to cluster individuals to their correct subpopulation. We show that flockture yields results similar to structure albeit with greater variability from run to run. flockture did perform better than structure when genotypes were composed of SNPs and differentiation was moderate (FST= 0.022-0.032). When differentiation was low, structure outperformed flockture for both marker types. On large data sets like those we simulated, it appears that flock's reliance on inference rules regarding its 'plateau record' is not helpful. Interpreting flock's algorithm as a special case of the model in structure should aid in understanding the program's output and behaviour.


Assuntos
Análise por Conglomerados , Biologia Computacional/métodos , Técnicas de Genotipagem/métodos , Software , Algoritmos , Bioestatística/métodos , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único
11.
Mitochondrial DNA ; 26(5): 672-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24148019

RESUMO

The Canada goose (Branta canadensis) entire mitochondrial genome of a bird from Western Pennsylvania has 16,760 bp (GenBank accession number NC 007011) and has been analyzed for gene locations, length, start codon and stop codons. This genome from a bird harvested during the non-migratory season is the REFSEQ and the haplotype is designated GCC-A. There are two rRNAs, 22 tRNAs, 13 protein-coding regions, and 1 displacement loop region. The base composition of mtDNA was A (30.2%), G (15.1%), C (32.1%), and T (22.6%), so the percentage of A and T (52.8%) was slightly higher than G and C. All genes except ND6 and eight tRNA genes (Gln, Ala, Asn, Cys, Tyr, Ser, Pro and Glu) are encoded on the heavy strand. The gene arrangement is the same as most birds and differs from mammals by an inversion of the mtDNA at the connection between the D-loop and the ND5 junctions.


Assuntos
Gansos/genética , Genoma Mitocondrial , Mitocôndrias/genética , Animais , Composição de Bases , Ordem dos Genes
12.
J Am Heart Assoc ; 3(1): e000408, 2014 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-24572251

RESUMO

BACKGROUND: The majority of established telestroke services are based on "hub-and-spoke" models for providing acute clinical assessment and thrombolysis. We report results from the first year of the successful implementation of a locally based telemedicine network, without the need of 1 or more hub hospitals, across a largely rural landscape. METHODS AND RESULTS: Following a successful pilot phase that demonstrated safety and feasibility, the East of England telestroke project was rolled out across 7 regional hospitals, covering an area of 7500 square miles and a population of 5.6 million to enable out-of-hours access to thrombolysis. Between November 2010 and November 2011, 142 telemedicine consultations were recorded out-of-hours. Seventy-four (52.11%) cases received thrombolysis. Median (IQR) onset-to-needle and door-to-needle times were 169 (141.5 to 201.5) minutes and 94 (72 to 113.5) minutes, respectively. Symptomatic hemorrhage rate was 7.3% and stroke mimic rate was 10.6%. CONCLUSIONS: We demonstrate the safety and effectiveness of a horizontal networking approach for stroke telemedicine, which may be applicable to areas where traditional "hub-and-spoke" models may not be geographically feasible.


Assuntos
Atenção à Saúde , Fibrinolíticos/uso terapêutico , Medicina Estatal , Acidente Vascular Cerebral/tratamento farmacológico , Telemedicina/métodos , Terapia Trombolítica , Plantão Médico , Idoso , Idoso de 80 Anos ou mais , Inglaterra , Feminino , Fibrinolíticos/efeitos adversos , Acessibilidade aos Serviços de Saúde , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Regionalização da Saúde , Consulta Remota , Características de Residência , Serviços de Saúde Rural , Acidente Vascular Cerebral/diagnóstico , Terapia Trombolítica/efeitos adversos , Fatores de Tempo , Tempo para o Tratamento , Resultado do Tratamento
13.
J Ultrasound Med ; 24(4): 475-82, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15784766

RESUMO

OBJECTIVE: The purpose of this study was to determine the reproducibility of measurements on duplex ultrasonography (DU) and air plethysmography (APG) in subjects with post-thrombotic syndrome. METHODS: Duplex ultrasonography and APG were used to measure indices of lower limb venous reflux in 15 limbs with a history of deep vein thrombosis and evidence of venous insufficiency as diagnosed by ultrasonography. Three limbs were in class 0; 4 were in classes 1 to 3; and 8 were in classes 4 to 6, according to clinical, etiologic, anatomic, and pathophysiologic clinical classification. Duplex ultrasonography was performed 3 times on the same day, and venous diameter, area, peak reflux velocity, reflux flow volume, and reflux duration measurements were obtained. Air plethysmography was performed on 2 days, 7 to 10 days apart, with 1 measurement on the first day and 2 measurements on the second day. Values obtained from APG included outflow fraction, venous filling index, ejection fraction, and residual volume fraction. The measurements were performed by a vascular technologist blinded to the previous test results. One-way analysis of variance, the Student paired t test, and Bland-Altman plots were used to examine the statistical differences of the DU and APG parameters for all measurements. RESULTS: The mean coefficient of variation for within-subject measurements of all DU and APG parameters measured was less than 10%. Bland-Altman plots showed that there were no apparent trends with increasing values over a wide range for any of the DU parameters, nor were there any for the APG parameters. CONCLUSIONS: Under ideal conditions, when measured by a highly trained technologist, both DU and APG showed satisfactory reproducibility.


Assuntos
Perna (Membro)/irrigação sanguínea , Pletismografia , Ultrassonografia Doppler Dupla , Insuficiência Venosa/diagnóstico por imagem , Insuficiência Venosa/diagnóstico , Adulto , Idoso , Ar , Análise de Variância , Velocidade do Fluxo Sanguíneo , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
14.
J Gen Virol ; 85(Pt 4): 863-868, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15039529

RESUMO

Cell lines derived from polydnavirus-associated wasps should constitute a valuable tool for investigations of polydnavirus replication, but none is yet available. In this work, we describe the first cell lines, named Hd-AA, -AD, -BBA and -K, to have been established from the ichneumonid wasp Hyposoter didymator, associated with the polydnavirus H. didymator ichnovirus (HdIV). Southern blot analysis indicated that the viral DNA was present in all four cell lines and co-localized with high molecular mass DNA, probably the wasp chromosomes. Northern blot analysis of mRNAs extracted from the AA cell line showed transcription of some HdIV-encoded genes, although at low level. The effects of ecdysone treatment, HdIV re-infection and 42 degrees C heat-shock were analysed in the AA cell line. No effect was detected at the DNA (virus replication) or RNA (gene expression) levels, which may be due to the limitation of the present available tools.


Assuntos
Polydnaviridae/fisiologia , Vespas/virologia , Animais , Sequência de Bases , Linhagem Celular , DNA Viral/genética , DNA Viral/isolamento & purificação , Microscopia Eletrônica , Dados de Sequência Molecular , Polydnaviridae/genética , RNA Viral/genética , RNA Viral/isolamento & purificação , Homologia de Sequência do Ácido Nucleico , Simbiose , Vespas/citologia
15.
J Virol ; 77(20): 11060-71, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14512554

RESUMO

The invertebrate parvovirus Junonia coenia densovirus (JcDNV) shares similarities with terminal hairpins and nonstructural (NS) protein activities of adeno-associated virus (AAV) despite their evolutionary divergence (B. Dumas, M. Jourdan, A. M. Pascaud, and M. Bergoin, Virology, 191:202-222, 1992, and C. Ding, M. Urabe, M. Bergoin, and R. M. Kotin, J. Virol. 76:338-345, 2002). We demonstrate here that persistent transgene expression in insect cells results from stable integration of transfected JcDNV-derived vectors into the host genome. To assess the integrative properties of JcDNV vectors, the green fluorescent protein (GFP) gfp marker gene was fused in frame into the major open reading frame (ORF1) of the viral sequence under the control of the P9 capsid protein promoter. In addition, the influence of the nonstructural proteins on the posttransfection maintenance of the vectors was examined by interruption of one or all three NS ORFs. Following transfection of Sf9 cells with each of the JcDNV constructs, clones showing persistent GFP expression were isolated. Structural analyses revealed that the majority of the JcDNV plasmid sequence was integrated into the genome of the fluorescent clones. Integration was observed whether or not NS proteins were expressed. However, the presence of NS genes in the constructs greatly influenced the number of integrated copies and their distribution in the host genome. Disruption of NS genes expression resulted in integration of head-to-tail concatemers at multiple sites within the genome. Further analyses demonstrated that the cis JcDNV 5' inverted terminal repeat region was the primary site of recombination. Sequence analyses of integration junctions showed rearrangements of both flanking and internal sequences for most integrations. These findings demonstrate that JcDNV vectors integrate into insect cells in a manner similar to AAV plasmids in mammalian cells.


Assuntos
Densovirus/genética , Vetores Genéticos , Transgenes , Integração Viral , Animais , Sequência de Bases , Dosagem de Genes , Genoma Viral , Dados de Sequência Molecular , Plasmídeos , Spodoptera , Transfecção , Proteínas não Estruturais Virais/genética
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