211 research outputs found

    Radio telemetry devices to monitor breathing in non-sedated animals

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    Radio telemetry equipment has significantly improved over the last 10-15 years and is increasingly being used in research for monitoring a variety of physiological parameters in non-sedated animals. The aim of this review is to provide an update on the current state of development of radio telemetry for recording respiration. Our literature review found only rare reports of respiratory studies via radio telemetry. Much of this article will hence report our experience with our custom-built radio telemetry devices designed for recording respiratory signals, together with numerous other physiological signals in lambs. Our current radio telemetry system allows to record 24 simultaneous signals 24h/day for several days. To our knowledge, this is the highest number of physiological signals, which can be recorded wirelessly. Our devices have been invaluable for studying respiration in our ovine models of preterm birth, reflux laryngitis, postnatal exposure to cigarette smoke, respiratory syncytial virus infection and nasal ventilation, all of which are relevant to neonatal respiratory problems

    A NAC domain mutation (E83Q) unlocks the pathogenicity of human alpha-synuclein and recapitulates its pathological diversity

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    The alpha-synuclein mutation E83Q, the first in the NAC domain of the protein, was recently identified in a patient with dementia with Lewy bodies. We investigated the effects of this mutation on the aggregation of aSyn monomers and the structure, morphology, dynamic, and seeding activity of the aSyn fibrils in neurons. We found that it markedly accelerates aSyn fibrillization and results in the formation of fibrils with distinct structural and dynamic properties. In cells, this mutation is associated with higher levels of aSyn, accumulation of pS129, and increased toxicity. In a neuronal seeding model of Lewy body (LB) formation, the E83Q mutation significantly enhances the internalization of fibrils into neurons, induces higher seeding activity, and results in the formation of diverse aSyn pathologies, including the formation of LB-like inclusions that recapitulate the immunohistochemical and morphological features of brainstem LBs observed in brains of patients with Parkinson’s disease

    Selective amplification of Brucella melitensis mRNA from a mixed host-pathogen total RNA

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    <p>Abstract</p> <p>Background</p> <p>Brucellosis is a worldwide anthropozoonotic disease caused by an in vivo intracellular pathogen belonging to genus <it>Brucella</it>. The characterization of brucelae transcriptome's during host-pathogen interaction has been limited due to the difficulty of obtaining an adequate quantity of good quality eukaryotic RNA-free pathogen RNA for downstream applications.</p> <p>Findings</p> <p>Here, we describe a combined protocol to prepare RNA from intracellular <it>B. melitensis </it>in a quantity and quality suitable for pathogen gene expression analysis. Initially, <it>B. melitensis </it>total RNA was enriched from a host:pathogen mixed RNA sample by reducing the eukaryotic RNA..Then, to increase the <it>Brucella </it>RNA concentration and simultaneously minimize the contaminated host RNA in the mixed sample, a specific primer set designed to anneal to all <it>B. melitensis </it>ORF allows the selective linear amplification of sense-strand prokaryotic transcripts in a previously enriched RNA sample.</p> <p>Conclusion</p> <p>The novelty of the method we present here allows analysis of the gene expression profile of <it>B. melitensis </it>when limited amounts of pathogen RNA are present, and is potentially applicable to both <it>in vivo </it>and <it>in vitro </it>models of infection, even at early infection time points.</p

    Current and emerging treatment of osteoporosis

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    The goal of treating a patient with recent fragility fracture should not only be to treat the patient in the acute phase but also to prevent further fractures. Interventions to increase bone mass to preventing further fragility fractures can be classified as non-pharmacological and pharmacological. All European and international guidelines base the need for treatment, not on the diagnosis of osteoporosis (based on the T-score), but on the risk of fracture, which is strongly influenced by the presence of a fragility fracture, especially vertebral or femoral fractures. Before treatment, it is important to make a differential diagnosis between primary and secondary osteoporosis because anti-osteoporotic drug treatment would be useless if the primary illness causing osteoporosis is not treated too. Some studies show that anti-osteoporotic drugs are frequently interrupted within 1 month of their prescription; this happens not so much due to the occurrence of adverse events but mostly because patients have not been sufficiently informed about the importance of taking the drug and because are not receiving personalised treatment. All data confirm that, in older people, vitamin D deficiency is highly prevalent and calcium intake is often not adequate. So, osteoporosis guidelines recommend calcium and vitamin D for all patients in association with antiosteoporotic therapy. We have many drugs for the treatment of patients at high risk of fracture, but we should use drugs based on evidence of their efficacy and safety in older-age subgroups, provided by targeted studies or extrapolated data. In this chapter, we describe efficacy, route of administration, adverse events and recent technical remarks of current antiresorptive and anabolic osteoporosis therapies. Furthermore, we describe emerging therapies, such as Abaloparatide and Romosozumab

    Understanding Communication Signals during Mycobacterial Latency through Predicted Genome-Wide Protein Interactions and Boolean Modeling

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    About 90% of the people infected with Mycobacterium tuberculosis carry latent bacteria that are believed to get activated upon immune suppression. One of the fundamental challenges in the control of tuberculosis is therefore to understand molecular mechanisms involved in the onset of latency and/or reactivation. We have attempted to address this problem at the systems level by a combination of predicted functional protein∶protein interactions, integration of functional interactions with large scale gene expression studies, predicted transcription regulatory network and finally simulations with a Boolean model of the network. Initially a prediction for genome-wide protein functional linkages was obtained based on genome-context methods using a Support Vector Machine. This set of protein functional linkages along with gene expression data of the available models of latency was employed to identify proteins involved in mediating switch signals during dormancy. We show that genes that are up and down regulated during dormancy are not only coordinately regulated under dormancy-like conditions but also under a variety of other experimental conditions. Their synchronized regulation indicates that they form a tightly regulated gene cluster and might form a latency-regulon. Conservation of these genes across bacterial species suggests a unique evolutionary history that might be associated with M. tuberculosis dormancy. Finally, simulations with a Boolean model based on the regulatory network with logical relationships derived from gene expression data reveals a bistable switch suggesting alternating latent and actively growing states. Our analysis based on the interaction network therefore reveals a potential model of M. tuberculosis latency

    Ultra-Rare Genetic Variation in the Epilepsies : A Whole-Exome Sequencing Study of 17,606 Individuals

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    Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA(A) receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNAIG, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.Peer reviewe

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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