1,571 research outputs found

    Genetic heterogeneity of porcine enteric caliciviruses identified from diarrhoeic piglets

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    Enteric caliciviruses (noroviruses and sapoviruses) are responsible for the majority of non-bacterial gastroenteritis in humans of all age groups. Analysis of the polymerase and capsid genes has provided evidence for a huge genetic diversity, but the understanding of their ecology is limited. In this study, we investigated the presence of porcine enteric caliciviruses in the faeces of piglets with diarrhoea. A total of 209 samples from 118 herds were analyszd and calicivirus RNA was detected by RT-PCR in 68 sample (32.5%) and in 46 herds (38.9%), alone or in mixed infection with group A and C rotaviruses. Sequence and phylogenetic analysis of the calicivirus-positive samples characterized the majority as genogroup III (GGIII) sapoviruses. Unclassified caliciviruses, distantly related to the representatives of the other sapovirus genogroups, were identified in five herds, while one outbreak was associated with a porcine sapovirus related genetically to human GGII and GGIV sapovirus strains. By converse, norovirus strains were not detected. Altogether, these data suggest the epidemiological relevance of porcine enteric caliciviruses and suggest a role in the etiology of piglets diarrhoe

    An Isolated Water Droplet in the Aqueous Solution of a Supramolecular Tetrahedral Cage

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    Water under nanoconfinement at ambient conditions has exhibited low-dimensional ice formation and liquid-solid phase transitions, but with structural and dynamical signatures which map onto known regions of waters phase diagram. Using THz absorption spectroscopy and ab initio molecular dynamics, we have investigated the ambient water confined in a supramolecular tetrahedral assembly, and determined that a distinct network of 9-10 water molecules is present within the nanocavity of the host. The low-frequency absorption spectrum and theoretical analysis of the water in the Ga4Ga_4L6L_612^{-12} host demonstrate that the structure and dynamics of the encapsulated droplet is distinct from any known phase of water. A further inference is that the release of the highly unusual encapsulated water droplet creates a strong thermodynamic driver for the high affinity binding of guests in aqueous solution for the Ga4Ga_4L6L_612^{-12} supramolecular construct

    Pilot Study on Quantitative Cervical Cord and Muscular MRI in Spinal Muscular Atrophy: Promising Biomarkers of Disease Evolution and Treatment?

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    Introduction: Nusinersen is a recent promising therapy approved for the treatment of spinal muscular atrophy (SMA), a rare disease characterized by the degeneration of alpha motor neurons (αMN) in the spinal cord (SC) leading to progressive muscle atrophy and dysfunction. Muscle and cervical SC quantitative magnetic resonance imaging (qMRI) has never been used to monitor drug treatment in SMA. The aim of this pilot study is to investigate whether qMRI can provide useful biomarkers for monitoring treatment efficacy in SMA. Methods: Three adult SMA 3a patients under treatment with nusinersen underwent longitudinal clinical and qMRI examinations every 4 months from baseline to 21-month follow-up. The qMRI protocol aimed to quantify thigh muscle fat fraction (FF) and water-T2 (w-T2) and to characterize SC volumes and microstructure. Eleven healthy controls underwent the same SC protocol (single time point). We evaluated clinical and imaging outcomes of SMA patients longitudinally and compared SC data between groups transversally. Results: Patient motor function was stable, with only Patient 2 showing moderate improvements. Average muscle FF was already high at baseline (50%) and progressed over time (57%). w-T2 was also slightly higher than previously published data at baseline and slightly decreased over time. Cross-sectional area of the whole SC, gray matter (GM), and ventral horns (VHs) of Patients 1 and 3 were reduced compared to controls and remained stable over time, while GM and VHs areas of Patient 2 slightly increased. We found altered diffusion and magnetization transfer parameters in SC structures of SMA patients compared to controls, thus suggesting changes in tissue microstructure and myelin content. Conclusion: In this pilot study, we found a progression of FF in thigh muscles of SMA 3a patients during nusinersen therapy and a concurrent slight reduction of w-T2 over time. The SC qMRI analysis confirmed previous imaging and histopathological studies suggesting degeneration of αMN of the VHs, resulting in GM atrophy and demyelination. Our longitudinal data suggest that qMRI could represent a feasible technique for capturing microstructural changes induced by SMA in vivo and a candidate methodology for monitoring the effects of treatment, once replicated on a larger cohort

    Graph Layouts by t‐SNE

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    We propose a new graph layout method based on a modification of the t-distributed Stochastic Neighbor Embedding (t-SNE) dimensionality reduction technique. Although t-SNE is one of the best techniques for visualizing high-dimensional data as 2D scatterplots, t-SNE has not been used in the context of classical graph layout. We propose a new graph layout method, tsNET, based on representing a graph with a distance matrix, which together with a modified t-SNE cost function results in desirable layouts. We evaluate our method by a formal comparison with state-of-the-art methods, both visually and via established quality metrics on a comprehensive benchmark, containing real-world and synthetic graphs. As evidenced by the quality metrics and visual inspection, tsNET produces excellent layouts

    BrainScope: interactive visual exploration of the spatial and temporal human brain transcriptome

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    Spatial and temporal brain transcriptomics has recently emerged as an invaluable data source for molecular neuroscience. The complexity of such data poses considerable challenges for analysis and visualization. We present BrainScope: a web portal for fast, interactive visual exploration of the Allen Atlases of the adult and developing human brain transcriptome. Through a novel methodology to explore high-dimensional data (dual t-SNE), BrainScope enables the linked, all-in-one visualization of genes and samples across the whole brain and genome, and across developmental stages. We show that densities in t-SNE scatter plots of the spatial samples coincide with anatomical regions, and that densities in t-SNE scatter plots of the genes represent gene co-expression modules that are significantly enriched for biological functions. We also show that the topography of the gene t-SNE maps reflect brain region-specific gene functions, enabling hypothesis and data driven research. We demonstrate the discovery potential of BrainScope through three examples: (i) analysis of cell type specific gene sets, (ii) analysis of a set of stable gene co-expression modules across the adult human donors and (iii) analysis of the evolution of co-expression of oligodendrocyte specific genes over developmental stages. BrainScope is publicly accessible at www.brainscope.nl.FSW – Publicaties zonder aanstelling Universiteit Leide

    Salmonella enterica serovar typhimurium exploits inflammation to modify swine intestinal microbiota

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    Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis. We compared the effects on the intestinal microbiota induced by a wild type and an attenuated S. Typhimurium in order to evaluate whether the modifications are correlated with the virulence of the strain. This study showed that Salmonella alters microbiota in a virulence-dependent manner. We found that the wild type S. Typhimurium induced inflammation and a reduction of specific protecting microbiota species (SCFA-producing bacteria) normally involved in providing a barrier against pathogens. Both these effects could contribute to impair colonization resistance, increasing the host susceptibility to wild type S. Typhimurium colonization. In contrast, the attenuated S. Typhimurium, which is characterized by a reduced ability to colonize the intestine, and by a very mild inflammatory response, was unable to successfully sustain competition with the microbiota

    Reproductive cycle, number of parities and faecal Salmonella spp. excretion in sows: a longitudinal study

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    The aim of the study was to evaluate the fecal excretion of Salmonella spp in sows with different number of parties, in distinct periods of the reproductive cycle. Two integrated farms in central Italy have been included in the study. The target populations were primaparous and multiparous (1-5 and more than 5 parities) sows, tested in different periods of the reprouductive cycle: 14 days before parturition (pre-partum), 2-5 days (post-partum), 20 days after parturition (post-partum 2) and gestation (24-31 days post-partum)

    Viral and murine interleukin-10 are correctly processed and retain their biological activity when produced in tobacco

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    Background: Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, with therapeutic applications in several autoimmune and inflammatory diseases. Oral administration of this cytokine alone, or in combination with disease-associated autoantigens could confer protection form the onset of a specific autoimmune disease through the induction of oral tolerance. Transgenic plants are attractive systems for production of therapeutic proteins because of the ability to do large scale-up at low cost, and the low maintenance requirements. They are highly amenable to oral administration and could become effective delivery systems without extensive protein purification. We investigated the ability of tobacco plants to produce high levels of biologically-active viral and murine IL-10. Results: Three different subcellular targeting strategies were assessed in transient expression experiments, and stable transgenic tobacco plants were generated with the constructs that yielded the highest accumulation levels by targeting the recombinant proteins to the endoplasmic reticulum. The best yields using this strategy in T1 plants were 10.8 and 37.0 \u3bcg/g fresh leaf weight for viral and murine IL-10, respectively. The recombinant proteins were purified from transgenic leaf material and characterized in terms of their N-glycan composition, dimerization and biological activity in in vitro assays. Both molecules formed stable dimers, were able to activate the IL-10 signaling pathway and to induce specific anti-inflammatory responses in mouse J774 macrophage cells. Conclusion: Tobacco plants are able to correctly process viral and murine IL-10 into biologically active dimers, therefore representing a suitable platform for the production for these cytokines. The accumulation levels obtained are high enough to allow delivery of an immunologically relevant dose of IL-10 in a reasonable amount of leaf material, without extensive purification. This study paves the way to performing feeding studies in mouse models of autoimmune diseases, that will allow the evaluation the immunomodulatory properties and effectiveness of the viral IL-10 in inducing oral tolerance compared to the murine protein

    Combination antiretroviral therapy and the risk of myocardial infarction

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