2,480 research outputs found

    Spatially and genetically distinct African trypanosome virulence variants defined by host interferon-g response

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    We describe 2 spatially distinct foci of human African trypansomiasis in eastern Uganda. The Tororo and Soroti foci of <i>Trypanosoma brucei rhodesiense</i> infection were genetically distinct as characterized by 6 microsatellite and 1 minisatellite polymorphic markers and were characterized by differences in disease progression and host-immune response. In particular, infections with the Tororo genotype exhibited an increased frequency of progression to and severity of the meningoencephalitic stage and higher plasma interferon (IFN)–γ concentration, compared with those with the Soroti genotype. We propose that the magnitude of the systemic IFN-γ response determines the time at which infected individuals develop central nervous system infection and that this is consistent with the recently described role of IFN-γ in facilitating blood-brain barrier transmigration of trypanosomes in an experimental model of infection. The identification of trypanosome isolates with differing disease progression phenotypes provides the first field-based genetic evidence for virulence variants in T. <i>brucei rhodesiense</i>

    A Comprehensive Workflow for General-Purpose Neural Modeling with Highly Configurable Neuromorphic Hardware Systems

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    In this paper we present a methodological framework that meets novel requirements emerging from upcoming types of accelerated and highly configurable neuromorphic hardware systems. We describe in detail a device with 45 million programmable and dynamic synapses that is currently under development, and we sketch the conceptual challenges that arise from taking this platform into operation. More specifically, we aim at the establishment of this neuromorphic system as a flexible and neuroscientifically valuable modeling tool that can be used by non-hardware-experts. We consider various functional aspects to be crucial for this purpose, and we introduce a consistent workflow with detailed descriptions of all involved modules that implement the suggested steps: The integration of the hardware interface into the simulator-independent model description language PyNN; a fully automated translation between the PyNN domain and appropriate hardware configurations; an executable specification of the future neuromorphic system that can be seamlessly integrated into this biology-to-hardware mapping process as a test bench for all software layers and possible hardware design modifications; an evaluation scheme that deploys models from a dedicated benchmark library, compares the results generated by virtual or prototype hardware devices with reference software simulations and analyzes the differences. The integration of these components into one hardware-software workflow provides an ecosystem for ongoing preparative studies that support the hardware design process and represents the basis for the maturity of the model-to-hardware mapping software. The functionality and flexibility of the latter is proven with a variety of experimental results

    A Phase 1 Randomized, Placebo-controlled, Observer-blinded Trial to Evaluate the Safety and Immunogenicity of Inactivated Streptococcus pneumoniae Whole-cell Vaccine in Adults

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    BACKGROUND: Broadly protective pneumococcal vaccines that are affordable for low-resource countries are needed. Streptococcus pneumoniae whole cell vaccine (wSp) is an investigational vaccine that contains killed cells from a nonencapsulated strain of S. pneumoniae (SPn) with aluminum hydroxide adjuvant. Studies in mice demonstrated protection against nasopharyngeal carriage (T-cell-mediated) and invasive pneumococcal disease (antibody-mediated). The aim of this randomized, double-blind, placebo-controlled Phase 1 study was to assess safety, tolerability and immunogenicity of wSp in healthy adults. METHODS: Forty-two participants were randomized into 3 dose cohorts to receive 0.1, 0.3, or 0.6 mg of wSp or saline intramuscularly. Participants received a 3-dose vaccination schedule spaced by 4-week intervals. Postvaccination assessments included solicited reactogenicity events through day 7, blood chemistry and hematology assessments at day 7, and adverse events (AEs) through day 84. Participants were monitored for serum antibody and peripheral blood mononuclear cell cytokine responses to pneumococcal antigens. A 6-month telephone follow-up was completed to assess for any additional AEs. RESULTS: wSp was safe and well tolerated. Reactogenicity was acceptable and no untoward safety signals were observed. wSp elicited potentially clinically significant rises (defined arbitrarily as at least a 2-fold rise) in immunoglobulin G responses to multiple pneumococcal antigens, including pneumococcal surface protein A and pneumolysin. Functional antibody responses were observed with the highest dose of wSp (0.6 mg). Increases in T-cell cytokine responses, including interleukin 17A, were also seen among wSp vaccines. CONCLUSIONS: wSp was safe and well tolerated in healthy US adults, eliciting pneumococcal antigen-specific antibody and T-cell cytokine responses

    Protocol for a double-blind randomised placebo-controlled trial of lithium carbonate in patients with amyotrophic lateral sclerosis (LiCALS) [Eudract number: 2008-006891-31].

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    BACKGROUND: Amyotrophic lateral sclerosis is a rapidly progressive neurodegenerative disorder characterised by loss of motor neurons leading to severe weakness and death from respiratory failure within 3-5 years. Riluzole prolongs survival in ALS. A published report has suggested a dramatic effect of lithium carbonate on survival. 44 patients were studied, with 16 randomly selected to take LiCO3 and riluzole and 28 allocated to take riluzole alone. In the group treated with lithium, no patients had died (i.e., 100% survival) at the end of the study (15 months from entry), compared to 71% surviving in the riluzole-only group. Although the trial can be criticised on several grounds, there is a substantial rationale from other laboratory studies that lithium is worth investigating therapeutically in amyotrophic lateral sclerosis. METHODS/DESIGN: LiCALS is a multi-centre double-blind randomised parallel group controlled trial of the efficacy, safety, and tolerability of lithium carbonate (LiCO3) at doses to achieve stable 'therapeutic' plasma levels (0.4-0.8 mmol/L), plus standard treatment, versus matched placebo plus standard treatment, in patients with amyotrophic lateral sclerosis. The study will be based in the UK, in partnership with the MND Association and DeNDRoN (the Dementias and Neurodegnerative Diseases Clinical Research Network). 220 patients will be recruited. All patients will be on the standard treatment for ALS of riluzole 100 mg daily. The primary outcome measure will be death from any cause at 18 months defined from the date of randomisation. Secondary outcome measures will be changes in three functional rating scales, the ALS Functional Rating Scale-Revised, The EuroQOL (EQ-5D), and the Hospital Anxiety and Depression Scale.Eligible patients will have El Escorial Possible, Laboratory-supported Probable, Probable or Definite amyotrophic lateral sclerosis with disease duration between 6 months and 36 months (inclusive), vital capacity ≥ 60% of predicted within 1 month prior to randomisation and age at least18 years. DISCUSSION: Patient recruitment began in June 2009 and the last patient is expected to complete the trial protocol in November 2011. TRIAL REGISTRATION: Current controlled trials ISRCTN83178718

    Population genetics of trypanosoma brucei rhodesiense: clonality and diversity within and between foci

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    African trypanosomes are unusual among pathogenic protozoa in that they can undergo their complete morphological life cycle in the tsetse fly vector with mating as a non-obligatory part of this development. Trypanosoma brucei rhodesiense, which infects humans and livestock in East and Southern Africa, has classically been described as a host-range variant of the non-human infective Trypanosoma brucei that occurs as stable clonal lineages. We have examined T. b. rhodesiense populations from East (Uganda) and Southern (Malawi) Africa using a panel of microsatellite markers, incorporating both spatial and temporal analyses. Our data demonstrate that Ugandan T. b. rhodesiense existed as clonal populations, with a small number of highly related genotypes and substantial linkage disequilibrium between pairs of loci. However, these populations were not stable as the dominant genotypes changed and the genetic diversity also reduced over time. Thus these populations do not conform to one of the criteria for strict clonality, namely stability of predominant genotypes over time, and our results show that, in a period in the mid 1990s, the previously predominant genotypes were not detected but were replaced by a novel clonal population with limited genetic relationship to the original population present between 1970 and 1990. In contrast, the Malawi T. b. rhodesiense population demonstrated significantly greater diversity and evidence for frequent genetic exchange. Therefore, the population genetics of T. b. rhodesiense is more complex than previously described. This has important implications for the spread of the single copy T. b. rhodesiense gene that allows human infectivity, and therefore the epidemiology of the human disease, as well as suggesting that these parasites represent an important organism to study the influence of optional recombination upon population genetic dynamics

    Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies

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    Funding: This study was funded by Mars Petcare and is part of a PhD studentship funded by the Scottish Funding Council Research Excellence Grant (REG). Authors WR and MN receive salary support from the Rural and Environment Science and Analytical Services Division (RESAS). With the exception of PH (employed by the funding organization), the funding organization did not have any additional role in the conceptualization, methodology, investigation, data curation, formal analysis, decision to publish, or preparation of the manuscript. PH was involved in study design, data interpretation, and manuscript preparation.Peer reviewedPublisher PD

    Stage progression and neurological symptoms in Trypanosoma brucei rhodesiense sleeping sickness: role of the CNS inflammatory response

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    Background: Human African trypanosomiasis progresses from an early (hemolymphatic) stage, through CNS invasion to the late (meningoencephalitic) stage. In experimental infections disease progression is associated with neuroinflammatory responses and neurological symptoms, but this concept requires evaluation in African trypanosomiasis patients, where correct diagnosis of the disease stage is of critical therapeutic importance. Methodology/Principal Findings: This was a retrospective study on a cohort of 115 T.b.rhodesiense HAT patients recruited in Eastern Uganda. Paired plasma and CSF samples allowed the measurement of peripheral and CNS immunoglobulin and of CSF cytokine synthesis. Cytokine and immunoglobulin expression were evaluated in relation to disease duration, stage progression and neurological symptoms. Neurological symptoms were not related to stage progression (with the exception of moderate coma). Increases in CNS immunoglobulin, IL-10 and TNF-α synthesis were associated with stage progression and were mirrored by a reduction in TGF-β levels in the CSF. There were no significant associations between CNS immunoglobulin and cytokine production and neurological signs of disease with the exception of moderate coma cases. Within the study group we identified diagnostically early stage cases with no CSF pleocytosis but intrathecal immunoglobulin synthesis and diagnostically late stage cases with marginal CSF pleocytosis and no detectable trypanosomes in the CSF. Conclusions: Our results demonstrate that there is not a direct linkage between stage progression, neurological signs of infection and neuroinflammatory responses in rhodesiense HAT. Neurological signs are observed in both early and late stages, and while intrathecal immunoglobulin synthesis is associated with neurological signs, these are also observed in cases lacking a CNS inflammatory response. While there is an increase in inflammatory cytokine production with stage progression, this is paralleled by increases in CSF IL-10. As stage diagnostics, the CSF immunoglobulins and cytokines studied do not have sufficient sensitivity to be of clinical value

    Evaluation of DSD training schools organized by cost action BM1303 "DSDnet"

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    Abstract Background The Differences of Sex Development network (DSDnet) aims to establish interactive relationships between clinicians, scientists, support groups and people with a difference of sex development (DSD) to improve the overall care for people affected by such condition. DSDnet has hosted three Training Schools (TSs) in Ghent, Bologna and Budapest between 2015 and 2017 with the primary purpose of providing multidisciplinary training to young professionals and encouraging ongoing activity in the field of DSD. The aim of our study was to evaluate the success and long-term effect effectiveness of these three TSs. Methods and results Eighty-seven trainees (70 women, 17 men) attended one of three TSs. The distribution of trainees according to their professional field was: 47 (54.0%) from Pediatrics/Endocrinology, 13 (14.9%) from Biology/Genetics, 12 (13.8%) from Psychology/Psychiatry and 15 (17.2%) from Surgical Professions. All trainees were asked to complete an evaluation form on the last day of the TS to gain feedback on how to improve the next one. A further survey was sent at the end of 2017 to provide information about the overall long-term impact of the TSs. Seventy-eight (89.7%) trainees completed evaluation forms at the end of the respective TSs. Replies to the subsequent survey were received from 76 (87.4%) of trainees. A total of 72/76 (94.7%) responders reported that they continue to be active in the field of DSD. The vast majority (64/68, 94.1%) reported that the TSs had enlarged their professional networks. Among the 76 respondent trainees, 11.8% (n = 9) had applied for a research grant and 10.5% (n = 8) had received a fellowship related to DSD since their TS attendance. Conclusions According to our results, the majority of TS participants continue to be active in the field of DSD and have enlarged their professional networks following participation at the TS. These findings indicate the need of this type of educational program and justify ongoing efforts to provide postgraduate multidisciplinary training in rare diseases such as DSD
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