271 resultados para anti-viral
Resumo:
Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen in animal models of myocarditis and is released from the heart during viral myocarditis, the characterization, role and significance of anti-cardiac myosin autoantibodies is poorly defined. In our study, we define the human cardiac myosin epitopes in human myocarditis and cardiomyopathies and establish a mechanism to explain how anti-cardiac myosin autoantibodies may contribute to heart disease. We show that autoantibodies to cardiac myosin in sera from myocarditis and dilated cardiomyopathies in humans targeted primarily epitopes in the S2 hinge region of cardiac myosin. In addition, anti-cardiac myosin antibodies in sera or purified IgG from myocarditis and cardiomyopathy targeted the beta-adrenergic receptor and induced antibody-mediated cAMP-dependent protein kinase A (PKA) cell signaling activity in heart cells. Antibody-mediated PKA activity in sera was abrogated by absorption with anti-human IgG. Antibody-mediated cell signaling of PKA was blocked by antigen-specific inhibition by human cardiac myosin or the beta-adrenergic receptor but not the alpha adrenergic receptor or bovine serum albumin. Propranolol, a beta blocker and inhibitor of the beta-adrenergic receptor pathway also blocked the antibody-mediated signaling of the beta-adrenergic receptor and PKA. The data suggest that IgG antibody against human cardiac myosin reacts with the beta-adrenergic receptor and triggers PKA signaling in heart cells. In summary, we have identified a new class of crossreactive autoantibodies against human cardiac myosin and the beta-adrenergic receptor in the heart. In addition, we have defined disease specific peptide epitopes in the human cardiac myosin rod S2 region in human myocarditis and cardiomyopathy as well as a mechanistic role of autoantibody in the pathogenesis of disease.
Resumo:
This study analyses the narrative elements of a little-known report into anti-venereal trials written by an Irish military physician-surgeon, Daniel O'Sullivan (1760–c.1797). It explores the way in which O'Sullivan as the narrator of the Historico-critical report creates medical heroes and anti-heroes as a means to criticise procedures initiated by staff in the Hospital General de San Andrés, Mexico City. The resulting work depicts a much less positive picture of medical trials and hospital authorities in this period than has been recorded to date, and provides a critical and complicated assessment of one of Spain's leading physicians of the nineteenth century, Francisco Javier Balmis (1753–1819).
Resumo:
Non-steroidal anti-inflammatory drugs (NSAIDs) have many anticarcinogenic properties via the inhibition of cyclooxygenase 2 (COX-2). Only one study, a cohort study examining risk of all cancers, investigated their role in cervical cancer with inconsistent findings between non-aspirin NSAIDs and aspirin. The aim of this study was to further investigate NSAID/aspirin use and cervical cancer risk.
Resumo:
Host defence peptides (HDPs) are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs) that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells). However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects.
Resumo:
Sera from seals infected during the 1988 European epizootic of phocine distemper virus and sera from Canadian seals collected since 1972 have been tested for the presence of antibodies to morbillivirus. Approximately one third of the Canadian sera have been shown to contain anti-morbillivirus antibodies; the possibility that these populations of seals provided a source of infection for European seals is discussed.
Resumo:
Purpose: The aetiology of primary brain tumours is largely unknown; the role of non-steroidal anti-inflammatory drugs (NSAIDs) or aspirin use and glioma risk has been inconclusive, but few population-based studies with reliable prescribing data have been conducted, and the association with meningioma risk has yet to be assessed. Methods: The UK Clinical Practice Research Datalink was used to assess the association between aspirin and non-aspirin NSAID use and primary brain tumour risk using a nested case-control study design. Conditional logistic regression analysis was performed on 5,052 brain tumour patients aged 16 years and over, diagnosed between 1987 and 2009 and 42,678 controls matched on year of birth, gender and general practice, adjusting for history of allergy and hormone replacement therapy use in the glioma and meningioma models, respectively.
Results: In conditional logistic regression analysis, excluding drug use in the year preceding the index date, there was no association with non-aspirin NSAID use (OR 0.96, 95 % CI 0.81-1.13) or glioma risk comparing the highest category of daily defined dose to non-users; however, non-aspirin NSAID use was positively associated with meningioma risk (OR 1.35, 95 % CI 1.06-1.71). No association was seen with high- or low-dose aspirin use irrespective of histology.
Conclusions: This large nested case-control study finds no association between aspirin or non-aspirin NSAID use and risk of glioma but a slight increased risk with non-aspirin NSAIDs and meningioma. © 2013 Springer Science+Business Media Dordrecht.
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.
Resumo:
Anti-islanding protection is becoming increasingly important due to the rapid installation of distributed generation from renewable resources like wind, tidal and wave, solar PV, bio-fuels, as well as from other resources like diesel. Unintentional islanding presents a potential risk for damaging utility plants and equipment connected from the demand side, as well as to public and personnel in utility plants. This paper investigates automatic islanding detection. This is achieved by deploying a statistical process control approach for fault detection with the real-time data acquired through a wide area measurement system, which is based on Phasor Measurement Unit (PMU) technology. In particular, the principal component analysis (PCA) is used to project the data into principal component subspace and residual space, and two statistics are used to detect the occurrence of fault. Then a fault reconstruction method is used to identify the fault and its development over time. The proposed scheme has been used in a real system and the results have confirmed that the proposed method can correctly identify the fault and islanding site.