975 research outputs found

    Envelope Determinants of Equine Lentiviral Vaccine Protection

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    Lentiviral envelope (Env) antigenic variation and associated immune evasion present major obstacles to vaccine development. The concept that Env is a critical determinant for vaccine efficacy is well accepted, however defined correlates of protection associated with Env variation have yet to be determined. We reported an attenuated equine infectious anemia virus (EIAV) vaccine study that directly examined the effect of lentiviral Env sequence variation on vaccine efficacy. The study identified a significant, inverse, linear correlation between vaccine efficacy and increasing divergence of the challenge virus Env gp90 protein compared to the vaccine virus gp90. The report demonstrated approximately 100% protection of immunized ponies from disease after challenge by virus with a homologous gp90 (EV0), and roughly 40% protection against challenge by virus (EV13) with a gp90 13% divergent from the vaccine strain. In the current study we examine whether the protection observed when challenging with the EV0 strain could be conferred to animals via chimeric challenge viruses between the EV0 and EV13 strains, allowing for mapping of protection to specific Env sequences. Viruses containing the EV13 proviral backbone and selected domains of the EV0 gp90 were constructed and in vitro and in vivo infectivity examined. Vaccine efficacy studies indicated that homology between the vaccine strain gp90 and the N-terminus of the challenge strain gp90 was capable of inducing immunity that resulted in significantly lower levels of post-challenge virus and significantly delayed the onset of disease. However, a homologous N-terminal region alone inserted in the EV13 backbone could not impart the 100% protection observed with the EV0 strain. Data presented here denote the complicated and potentially contradictory relationship between in vitro virulence and in vivo pathogenicity. The study highlights the importance of structural conformation for immunogens and emphasizes the need for antibody binding, not neutralizing, assays that correlate with vaccine protection. © 2013 Craigo et al

    The clinical features of the piriformis syndrome: a systematic review

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    Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis

    Nonequilibrium Dynamics in Noncommutative Spacetime

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    We study the effects of spacetime noncommutativity on the nonequilibrium dynamics of particles in a thermal bath. We show that the noncommutative thermal bath does not suffer from any further IR/UV mixing problem in the sense that all the finite-temperature non-planar quantities are free from infrared singularities. We also point out that the combined effect of finite temperature and noncommutative geometry has a distinct effect on the nonequilibrium dynamics of particles propagating in a thermal bath: depending on the momentum of the mode of concern, noncommutative geometry may switch on or switch off their decay and thermalization. This momentum dependent alternation of the decay and thermalization rates could have significant impacts on the nonequilibrium phenomena in the early universe at which spacetime noncommutativity may be present. Our results suggest a re-examination of some of the important processes in the early universe such as reheating after inflation, baryogenesis and the freeze-out of superheavy dark matter candidates.Comment: 24 pages, 2 figure

    DNA sense-and-respond protein modules for mammalian cells

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    We generated synthetic protein components that can detect specific DNA sequences and subsequently trigger a desired intracellular response. These modular sensors exploit the programmability of zinc-finger DNA recognition to drive the intein-mediated splicing of an artificial trans-activator that signals to a genetic circuit containing a given reporter or response gene. We used the sensors to mediate sequence recognition−induced apoptosis as well as to detect and report a viral infection. This work establishes a synthetic biology framework for endowing mammalian cells with sentinel capabilities, which provides a programmable means to cull infected cells. It may also be used to identify positively transduced or transfected cells, isolate recipients of intentional genomic edits and increase the repertoire of inducible parts in synthetic biology.United States. Defense Advanced Research Projects Agency (DARPA-BAA-11-23)Defense Threat Reduction Agency (DTRA) (HDTRA1-14-1-0006)United States. Air Force Office of Scientific Research (FA9550-14-1-0060

    Adiponectin SNP45TG is associated with gestational diabetes mellitus

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    INTRODUCTION: Diabetes and pregnancy can be associated in two ways: pregnancy that occurs in women who are already diabetic (diabetes of pre-gestational origin); and diabetes that occur in women who are already pregnant [gestational diabetes mellitus (GDM) (O'sullivan 1961)]. Patients with previous GDM history have higher risk of developing diabetes outside of pregnancy. Accumulating literature had suggested that adiponectin plays a role in the pathophysiology of this metabolic syndrome, and several of the common single nucleotide polymorphisms (SNP) in adiponectin gene have been identified in type 2 diabetes. Thus, one of the commonly found SNP was studied to determine its association with GDM. OBJECTIVE: To identify the association of SNP45TG with GDM. METHODS: This is a cross-sectional study involving pregnant mothers of <18 gestational weeks, who were recruited from three local antenatal clinics in Selangor, Malaysia. Their genomic DNA was extracted from EDTA treated whole blood using commercialized kit. Adiponectin gene was amplified through conventional PCR and SNP was detected using restriction enzyme SmaI. Plasma adiponectin level, fructosamine level and HbA(1c) percentage were also examined. RESULTS: Among the 79 antenatal patients recruited, 53 patients were normal and 26 were diagnosed with GDM. Among the 53 normal patients, 18 carry TG/GG genotype. Meanwhile, among the 26 patients that were diagnosed with GDM 15 carry TG/GG genotype. Significant association was found between SNP45TG with GDM ( χ(2) = 4.038; P < 0.05). In addition, normal patients with TT genotype have significantly higher plasma adiponectin level compared to other groups. CONCLUSION: We concluded that SNP45TG in adiponectin gene is associated with the occurrence of GDM

    Valacyclovir in the treatment of acute retinal necrosis

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    Background: To report the outcome of oral valacyclovir as the sole antiviral therapy for patients with acute retinal necrosis (ARN). Methods: This study reports a retrospective, interventional case series of nine consecutive patients with ten eyes with newly diagnosed ARN treated with oral valacyclovir as the sole antiviral agent. Eight patients received oral valacyclovir 2 g tid (Valtrex, GlaxoSmithKline) and one patient with impaired renal function received oral 1 g tid. The main outcome measures were response to treatment, time to initial response to treatment, time to complete resolution of retinitis, best corrected visual acuity (BCVA) at final follow-up, retinal detachment and development of recurrent or second eye disease. Results: Retinitis resolved in ten of ten (100%) affected eyes. The median time to initial detectable response was seven days and the median time to complete resolution was 21 days. A final BCVA of 20/40 or better was achieved in 6/10 (60%) of eyes. 3/10 eyes (30%) developed a retinal detachment. No patients developed either disease reactivation or second eye involvement over the course of the study (mean follow up 31 weeks, range 7 to 104 weeks). Conclusions: Treatment with oral valacyclovir as the sole antiviral therapy resulted in complete resolution of retinitis. Final BCVA and retinal detachment rate were comparable with previously reported outcomes for intravenous acyclovi

    Evaluation of invasive and non-invasive methods for the diagnosis of Helicobacter pylori infection in symptomatic children and adolescents

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    CONTEXT: Multiple diagnostic methods are available for the detection of Helicobacter pylori infection, but at present no single one can be used as the gold standard. OBJECTIVE: The aim of this study was to evaluate the diagnostic accuracy of 3 invasive and 2 non-invasive methods for detection of Helicobacter pylori infection in symptomatic children and adolescents. DESIGN: Prospective cohort study SETTING: Peptic Disease outpatients service, Discipline of Pediatric Gastroenterology, Universidade Federal de São Paulo (UNIFESP) / Escola Paulista de Medicina. PATIENTS: Forty-seven patients who underwent endoscopy because of dyspeptic symptoms. DIAGNOSTIC METHODS: Endoscopy with gastric biopsies for 3 invasive (rapid urease test, histology and culture) and 2 non-invasive methods (a commercial ELISA serology and 13carbon urea breath test - isotope ratio mass spectrometry) for detection of Helicobacter pylori infection. MAIN MEASUREMENTS: Sensitivity, specificity, positive and negative predictive values of each method and agreement and disagreement rates between the methods. RESULTS: Forty-seven patients [mean age, 11y9mo (SD 2y10mo), 27 female and 20 male]; 62% of them were Helicobacter pylori-positive. All methods agreed in 61%, and were negative in 21% and positive in 40%. The greatest concordance between 2 methods occurred between the invasive methods: histology and rapid urease test (89.6%) and histology and culture (87.5%). The greatest sensitivity, considering Helicobacter pylori-positive cases, for any combination of 3 or more tests, was achieved by the rapid urease test (S=100%), followed by histology, serology and 13carbon-urea breath test (S=93.1%) and lastly by culture (S=79.3%). The highest specificity was obtained by histology (100%) and culture (100%), followed by the rapid urease test (84.2%), serology (78.9%) and 13carbon-urea breath test (78.9%). CONCLUSIONS: Our results suggest that among invasive methods, an association between the rapid urease test and histology constituted the best choice for the detection of Helicobacter pylori infection. If results of histology and the rapid urease test are different, serology may be recommended.CONTEXTO: Vários métodos diagnósticos estão disponíveis para a detecção da infecção por Helicobacter pylori (Hp), porém, até o presente momento, não há um teste que possa ser utilizado isoladamente como padrão-ouro. OBJETIVO: Avaliar a acurácia de três métodos invasivos e dois não-invasivos na detecção da infecção por Hp em crianças e adolescentes sintomáticos. TIPO DE ESTUDO: Estudo coorte prospectivo. LOCAL: Ambulatório de Doença Péptica, Disciplina de Gastroenterologia Pediátrica, Universidade Federal de São Paulo (UNIFESP) / Escola Paulista de Medicina. PACIENTES: 47 pacientes sintomáticos que realizaram exame endoscópico devido a sintomas dispépticos. MÉTODOS DIAGNÓSTICOS: Exame endoscópico com biopsias gástricas para três métodos invasivos (teste rápido da urease, histologia e cultura) e dois métodos não-invasivos (teste sorológico ELISA industrializado e teste respiratório com uréia marcada com Carbono13). VARIÁVEIS ESTUDADAS: Sensibilidade, especificidade, valor preditivo positivo e negativo de cada método e taxas de concordância e discordância entre os métodos. RESULTADOS: 47 pacientes [idade média de 11a9m (DP 2a10m), 27 do sexo feminino e 20 do masculino], 62% deles com infecção por Hp. Todos os 5 métodos concordaram em 61%, sendo negativo em 21% e positivo em 40%. As maiores concordâncias entre dois métodos ocorreram entre os métodos invasivos: histologia e teste rápido da urease (89,6%) e entre a histologia e cultura (87,5%). A maior sensibilidade, considerando como Hp positivo, qualquer combinação de 3 ou mais testes, foi encontrada no teste rápido da urease (S=100%), seguido pela histologia, sorologia e o teste respiratório com uréia marcada com Carbono13 (S=93,1%) e por fim a cultura (S=79,3%). A maior especificidade foi obtida pela histologia e cultura (100%), seguidos pelo teste rápido da urease (84,2%), sorologia (78,9%) e teste respiratório com uréia marcada com Carbono13 (78,9%). CONCLUSÕES: Nossos resultados sugerem que, entre os métodos invasivos, a associação do teste rápido da urease e histologia constituem a melhor escolha para a detecção da infecção por Hp. Se os resultados da histologia e do teste rápido da urease forem discordantes é recomendada a sorologia.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Pediatric DepartmentUNIFESP, EPM, Pediatric DepartmentSciEL

    Role of oxidative stress in the pathology and management of human tuberculosis

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    Copyright © 2018 Madhur D. Shastri et al. Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis, is the leading cause of mortality worldwide due to a single infectious agent. The pathogen spreads primarily via aerosols and especially infects the alveolar macrophages in the lungs. The lung has evolved various biological mechanisms, including oxidative stress (OS) responses, to counteract TB infection. M. tuberculosis infection triggers the generation of reactive oxygen species by host phagocytic cells (primarily macrophages). The development of resistance to commonly prescribed antibiotics poses a challenge to treat TB; this commonly manifests as multidrug resistant tuberculosis (MDR-TB). OS and antioxidant defense mechanisms play key roles during TB infection and treatment. For instance, several established first-/second-line antitubercle antibiotics are administered in an inactive form and subsequently transformed into their active form by components of the OS responses of both host (nitric oxide, S-oxidation) and pathogen (catalase/peroxidase enzyme, EthA). Additionally, M. tuberculosis has developed mechanisms to survive high OS burden in the host, including the increased bacterial NADH/NAD+ ratio and enhanced intracellular survival (Eis) protein, peroxiredoxin, superoxide dismutases, and catalases. Here, we review the interplay between lung OS and its effects on both activation of antitubercle antibiotics and the strategies employed by M. tuberculosis that are essential for survival of both drug-susceptible and drug-resistant bacterial subtypes. We then outline potential new therapies that are based on combining standard antitubercular antibiotics with adjuvant agents that could limit the ability of M. tuberculosis to counter the host's OS response

    A distinct role for B1b lymphocytes in T cell-independent immunity

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    Pathogenesis of infectious disease is not only determined by the virulence of the microbe but also by the immune status of the host. Vaccination is the most effective means to control infectious diseases. A hallmark of the adaptive immune system is the generation of B cell memory, which provides a long-lasting protective antibody response that is central to the concept of vaccination. Recent studies revealed a distinct function for B1b lymphocytes, a minor subset of mature B cells that closely resembles that of memory B cells in a number of aspects. In contrast to the development of conventional B cell memory, which requires the formation of germinal centers and T cells, the development of B1b cell-mediated long-lasting antibody responses occurs independent of T cell help. T cell-independent (TI) antigens are important virulence factors expressed by a number of bacterial pathogens, including those associated with biological threats. TI antigens cannot be processed and presented to T cells and therefore are known to possess restricted T cell-dependent (TD) immunogenicity. Nevertheless, specific recognition of TI antigens by B1b cells and the highly protective antibody responses mounted by them clearly indicate a crucial role for this subset of B cells. Understanding the mechanisms of long-term immunity conferred by B1b cells may lead to improved vaccine efficacy for a variety of TI antigens

    Re-examining the Unified Theory of Acceptance and Use of Technology (UTAUT): Towards a Revised Theoretical Model

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    YesBased on a critical review of the Unified Theory of Acceptance and Use of Technology (UTAUT), this study first formalized an alternative theoretical model for explaining the acceptance and use of information system (IS) and information technology (IT) innovations. The revised theoretical model was then empirically examined using a combination of meta-analysis and structural equation modelling (MASEM) techniques. The meta-analysis was based on 1600 observations on 21 relationships coded from 162 prior studies on IS/IT acceptance and use. The SEM analysis showed that attitude: was central to behavioural intentions and usage behaviours, partially mediated the effects of exogenous constructs on behavioural intentions, and had a direct influence on usage behaviours. A number of implications for theory and practice are derived based on the findings
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