10 research outputs found

    Infectious Offspring: How Birds Acquire and Transmit an Avian Polyomavirus in the Wild

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    Detailed patterns of primary virus acquisition and subsequent dispersal in wild vertebrate populations are virtually absent. We show that nestlings of a songbird acquire polyomavirus infections from larval blowflies, common nest ectoparasites of cavity-nesting birds, while breeding adults acquire and renew the same viral infections via cloacal shedding from their offspring. Infections by these DNA viruses, known potential pathogens producing disease in some bird species, therefore follow an ‘upwards vertical’ route of an environmental nature mimicking horizontal transmission within families, as evidenced by patterns of viral infection in adults and young of experimental, cross-fostered offspring. This previously undescribed route of viral transmission from ectoparasites to offspring to parent hosts may be a common mechanism of virus dispersal in many taxa that display parental care

    The Membrane Fusion Step of Vaccinia Virus Entry Is Cooperatively Mediated by Multiple Viral Proteins and Host Cell Components

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    For many viruses, one or two proteins allow cell attachment and entry, which occurs through the plasma membrane or following endocytosis at low pH. In contrast, vaccinia virus (VACV) enters cells by both neutral and low pH routes; four proteins mediate cell attachment and twelve that are associated in a membrane complex and conserved in all poxviruses are dedicated to entry. The aim of the present study was to determine the roles of cellular and viral proteins in initial stages of entry, specifically fusion of the membranes of the mature virion and cell. For analysis of the role of cellular components, we used well characterized inhibitors and measured binding of a recombinant VACV virion containing Gaussia luciferase fused to a core protein; viral and cellular membrane lipid mixing with a self-quenching fluorescent probe in the virion membrane; and core entry with a recombinant VACV expressing firefly luciferase and electron microscopy. We determined that inhibitors of tyrosine protein kinases, dynamin GTPase and actin dynamics had little effect on binding of virions to cells but impaired membrane fusion, whereas partial cholesterol depletion and inhibitors of endosomal acidification and membrane blebbing had a severe effect at the later stage of core entry. To determine the role of viral proteins, virions lacking individual membrane components were purified from cells infected with members of a panel of ten conditional-lethal inducible mutants. Each of the entry protein-deficient virions had severely reduced infectivity and except for A28, L1 and L5 greatly impaired membrane fusion. In addition, a potent neutralizing L1 monoclonal antibody blocked entry at a post-membrane lipid-mixing step. Taken together, these results suggested a 2-step entry model and implicated an unprecedented number of viral proteins and cellular components involved in signaling and actin rearrangement for initiation of virus-cell membrane fusion during poxvirus entry

    Carpal Tunnel Syndrome: A Review of the Recent Literature

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    Carpal Tunnel Syndrome (CTS) remains a puzzling and disabling condition present in 3.8% of the general population. CTS is the most well-known and frequent form of median nerve entrapment, and accounts for 90% of all entrapment neuropathies. This review aims to provide an overview of this common condition, with an emphasis on the pathophysiology involved in CTS. The clinical presentation and risk factors associated with CTS are discussed in this paper. Also, the various methods of diagnosis are explored; including nerve conduction studies, ultrasound, and magnetic resonance imaging

    Toxicological perspectives of inhaled therapeutics and nanoparticles

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    Introduction: The human respiratory system is an important route for the entry of inhaled therapeutics into the body to treat diseases. Inhaled materials may consist of gases, vapours, aerosols and particulates. In all cases, assessing the toxicological effect of inhaled therapeutics has many challenges. Areas covered: This article provides an overview of in vivo and in vitro models for testing the toxicity of inhaled therapeutics and nanoparticles implemented in drug delivery. Traditionally, inhalation toxicity has been performed on test animals to identify the median lethal concentration of airborne materials. Later maximum tolerable concentration denoted by LC0 has been introduced as a more ethically acceptable end point. More recently, in vitro methods have been developed, allowing the direct exposure of airborne material to cultured human target cells on permeable porous membranes at the air–liquid interface. Expert opinion: Modifications of current inhalation therapies, new pulmonary medications for respiratory diseases and implementation of the respiratory tract for systemic drug delivery are providing new challenges when conducting well-designed inhalation toxicology studies. In particular, the area of nanoparticles and nanocarriers is of critical toxicological concern. There is a need to develop toxicological test models, which characterise the toxic response and cellular interaction between inhaled particles and the respiratory system

    Avaliação do questionário de Boston aplicado no pós-operatório tardio da síndrome do tunel do carpo operados pela técnica de retinaculótomo de paine por via palmar Evaluation of Boston questionnaire applied at late pos-operative period of carpal tunnel syndrome operated with the paine retinaculatome through palmar port

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    Entre os anos de 1995 e 1998, foram realizadas 112 cirurgias para tratamento da Síndrome do Túnel do Carpo (STC) pela técnica de incisão palmar e utilização do retináculo de Paine. Com o objetivo de avaliar os resultados em longo prazo, os pacientes foram convocados. Houve o retorno de 44 pacientes. Deste total, três pacientes, por terem doenças associadas, foram excluídos, resultando, um total de 53 mãos analisadas. Apresentaremos os resultados da avaliação subjetiva, obtidos através da aplicação de um teste de auto-avaliação chamado de questionário de Boston. Este questionário consiste em perguntas que avaliam a gravidade dos sintomas e o estado funcional no momento da aplicação do mesmo. Através da aplicação do referido questionário encontramos um escore de 1,41 ± 0,57 para gravidade dos sintomas e 1,59 ± 0,93 para o estado funcional. Como este questionário não foi aplicado no pré-operatório deste grupo de pacientes analisados, comparou-se a pontuação obtida com as encontradas na literatura pertinente. Os resultados obtidos demonstraram que as pontuações pós-operatórias são similares àquelas existentes na literatura, mesmo sendo referidas a tempos diferentes de seguimento pós-operatórios, concluindo que havendo uma melhora dos sintomas, o questionário de Boston é sensível a esta mudança clínica.<br>Between the years of 1995 and 1998, 112 surgeries were performed for treating Carpal Tunnel Syndrome (CTS) using the technique of palmar incision employing the Paine retinaculum. With the objective of analyzing results in the long-term, the patients were called for review. Forty four patients returned. From these, three patients were excluded due to associated diseases, thus resulting in a total of 53 hands assessed. Here we present the results of the subjective evaluation achieved by applying a self-assessment test called Boston questionnaire. This questionnaire consists of questions evaluating symptoms severity and functional status at the moment of its application. By applying this questionnaire, we found a score of 1.41 ± 0.57 for symptoms severity and of 1.59 ± 0.93 for functional status. As this questionnaire was not applied at the pre-operative period for those patients assessed, its scores were thus compared to those found in pertinent literature. The achieved results show that post-operative scores are similar to those described in literature, even when reported in different postoperative follow-up times, thereby concluding that when symptoms are improved, the Boston questionnaire is sensitive to that clinical change

    Spondylolysis and spondylolytic spondylolisthesis

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