66 resultados para viral fitness


Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marine sponges have never been directly examined with respect to the presence of viruses or their potential involvement in horizontal gene transfer. Here we demonstrate for the first time, the presence of viruses in the marine sponge Hymeniacidon perlevis. Moreover, bacterial 16s rDNA was detected in DNA isolated from these viruses, indicating that phage-derived transduction appears to occur in H. perlevis. Phylogenetic analysis revealed that bacterial 16s rDNA isolated from sponge-derived viral and total DNA differed significantly, indicating that not all species are equally involved in transduction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Porcine circovirus type 2 (PCV2) was retrospectively identified by serology in swine populations as an asymptomatic infection at least 25 years prior to the first reported case of PCV2-associated postweaning multisystemit wasting syndrome (PMWS). To investigate the sudden emergence of PMWS, viral sequences were amplified from frozen archived (1970-1971) porcine tissues and the complete genome of archival PCV2 was determined. The ORF1 gene product (viral DNA replicase) was homologous to contemporary PCV2 ORF1. In ORF2 (viral nucleocapsid gene) archival PCV2, a consistent linear nine-base sequence difference at base positions 1331 through 1339 was observed.The deduced amino acid sequence from these base changes alters the nucleocapsid conformation within the second immunogenic epitope from a hydrophobic (contemporary PCV2) to a hydrophilic (archival PCV2) configuration.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the past decades, numerous types of nanomedicines have been developed for the efficient and safe delivery of nucleic acid-based drugs for cancer therapy. Given that the destination sites for nucleic acid-based drugs are inside cancer cells, delivery systems need to be both targeted and shielded in order to overcome the extracellular and intracellular barriers. One of the major obstacles that has hindered the translation of nanotechnology-based gene-delivery systems into the clinic has been the complexity of the design and assembly processes, resulting in non-uniform nanocarriers with unpredictable surface properties and efficiencies. Consequently, no product has reached the clinic yet. In order to address this shortcoming, a multifunctional targeted biopolymer is genetically engineered in one step, eliminating the need for multiple chemical conjugations. Then, by systematic modulation of the ratios of the targeted recombinant vector to PEGylated peptides of different sizes, a library of targeted-shielded viral-mimetic nanoparticles (VMNs) with diverse surface properties are assembled. Through the use of physicochemical and biological assays, targeted-shielded VMNs with remarkably high transfection efficiencies (>95%) are screened. In addition, the batch-to-batch variability of the assembled targeted-shielded VMNs in terms of uniformity and efficiency is examined and, in both cases, the coefficient of variation is calculated to be below 20%, indicating a highly reproducible and uniform system. These results provide design parameters for engineering uniform, targeted-shielded VMNs with very high cell transfection rates that exhibit the important characteristics for in vivo translation. These design parameters and principles could be used to tailor-make and assemble targeted-shielded VMNs that could deliver any nucleic acid payload to any mammalian cell type.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To examine the effects of 30 min of self-paced, non-supervised, brisk walking, 5 days per week on the health and fitness of people aged 50-65 years.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Toll-like receptors (TLRs) sense pathogen-associated molecules and respond by inducing cytokines and type I interferon. Here we show that genetic ablation of the E3 ubiquitin ligase Pellino3 augmented the expression of type I interferon but not of proinflammatory cytokines in response to TLR3 activation. Pellino3-deficient mice had greater resistance against the pathogenic and lethal effects of encephalomyocarditis virus (EMCV). TLR3 signaling induced Pellino3, which in turn interacted with and ubiquitinated TRAF6. This modification suppressed the ability of TRAF6 to interact with and activate IRF7, resulting in downregulation of type I interferon expression. Our findings highlight a new physiological role for Pellino3 and define a new autoregulatory network for controlling type I interferon expression. © 2012 Nature America, Inc. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rationale: Ex vivo, bronchial epithelial cells from people with asthma are more susceptible to rhinovirus infection caused by deficient induction of the antiviral protein, IFN-b. Exogenous IFN-b restores antiviral activity.

Objectives: To compare the efficacy and safety of inhaled IFN-b with placebo administered to people with asthma after onset of cold symptoms to prevent or attenuate asthma symptoms caused by respiratory viruses.

Methods: A total of 147 people with asthma on inhaled corticosteroids (British Thoracic Society Steps 2–5), with a history of virus-associated exacerbations, were randomized to 14-day treatment with inhaled IFN-b (n = 72) or placebo (n = 75) within 24 hours of developing cold symptoms and were assessed clinically, with relevant samples collected to assess virus infection and antiviral responses.

Measurements and Main Results: A total of 91% of randomized patients developed a defined cold. In this modified intention-to-treat population, asthma symptoms did not get clinically significantly worse
(mean change in six-item Asthma Control Questionnaire ,0.5) and IFN-b treatment had no significant effect on this primary endpoint, although it enhanced morning peak expiratory flow recovery (P = 0.033), reduced the need for additional treatment, and boosted innate immunity as assessed by blood and sputum biomarkers. In an exploratory analysis of the subset ofmore difficult-to-treat, Step 4-5 peoplewith asthma (n = 27 IFN-b; n = 31 placebo), Asthma Control Questionnaire-6 increased significantly on placebo; this was prevented by IFN-b (P = 0.004).

Conclusions: Although the trial did not meet its primary endpoint, it suggests that inhaled IFN-b is a potential treatment for virus-induced deteriorations of asthma in difficult-to-treat people with asthma and supports the needforfurther, adequately powered, trialsin this population. Clinical trial registered with www.clinicaltrials.gov (NCT 01126177).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Effectiveness of brief/minimal contact self-activation interventions that encourage participation in physical activity (PA) for chronic low back pain (CLBP >12 weeks) is unproven. The primary objective of this assessor-blinded randomized controlled trial was to investigate the difference between an individualized walking programme (WP), group exercise class (EC), and usual physiotherapy (UP, control) in mean change in functional disability at 6 months. A sample of 246 participants with CLBP aged 18 to 65 years (79 men and 167 women; mean age ± SD: 45.4 ± 11.4 years) were recruited from 5 outpatient physiotherapy departments in Dublin, Ireland. Consenting participants completed self-report measures of functional disability, pain, quality of life, psychosocial beliefs, and PA were randomly allocated to the WP (n = 82), EC (n = 83), or UP (n = 81) and followed up at 3 (81%; n = 200), 6 (80.1%; n = 197), and 12 months (76.4%; n = 188). Cost diaries were completed at all follow-ups. An intention-to-treat analysis using a mixed between-within repeated-measures analysis of covariance found significant improvements over time on the Oswestry Disability Index (Primary Outcome), the Numerical Rating Scale, Fear Avoidance-PA scale, and the EuroQol EQ-5D-3L Weighted Health Index (P < 0.05), but no significant between-group differences and small between-group effect sizes (WP: mean difference at 6 months, 6.89 Oswestry Disability Index points, 95% confidence interval [CI] -3.64 to -10.15; EC: -5.91, CI: -2.68 to -9.15; UP: -5.09, CI: -1.93 to -8.24). The WP had the lowest mean costs and the highest level of adherence. Supervised walking provides an effective alternative to current forms of CLBP management.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Farmed fish are typically genetically different from wild conspecifics. Escapees from fish farms may contribute one-way gene flow from farm to wild gene pools, which can depress population productivity, dilute local adaptations and disrupt coadapted gene complexes. Here, we reanalyse data from two experiments (McGinnity et al., 1997, 2003) where performance of Atlantic salmon (Salmo salar) progeny originating from experimental crosses between farm and wild parents (in three different cohorts) were measured in a natural stream under common garden conditions. Previous published analyses focussed on group-level differences but did not account for pedigree structure, as we do here using modern mixed-effect models. Offspring with one or two farm parents exhibited poorer survival in their first and second year of life compared with those with two wild parents and these group-level inferences were robust to excluding outlier families. Variation in performance among farm, hybrid and wild families was generally similar in magnitude. Farm offspring were generally larger at all life stages examined than wild offspring, but the differences were moderate (5–20%) and similar in magnitude in the wild versus hatchery environments. Quantitative genetic analyses conducted using a Bayesian framework revealed moderate heritability in juvenile fork length and mass and positive genetic correlations (>0.85) between these morphological traits. Our study confirms (using more rigorous statistical techniques) previous studies showing that offspring of wild fish invariably have higher fitness and contributes fresh insights into family-level variation in performance of farm, wild and hybrid Atlantic salmon families in the wild. It also adds to a small, but growing, number of studies that estimate key evolutionary parameters in wild salmonid populations. Such information is vital in modelling the impacts of introgression by escaped farm salmon.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Respiratory viral infections are a common cause of acute coughing, an irritating symptom for the patient and an important mechanism of transmission for the virus. Although poorly described, the inflammatory consequences of infection likely induce coughing by chemical (inflammatory mediator) or mechanical (mucous) activation of the cough-evoking sensory nerves that innervate the airway wall. For some individuals, acute cough can evolve into a chronic condition, in which cough and aberrant airway sensations long outlast the initial viral infection. This suggests that some viruses have the capacity to induce persistent plasticity in the neural pathways mediating cough. In this brief review we present the clinical evidence of acute and chronic neural dysfunction following viral respiratory tract infections and explore possible mechanisms by which the nervous system may undergo activation, sensitization and plasticity.