13 research outputs found

    Staphylococcus aureus Protein A Binds to Osteoblasts and Triggers Signals That Weaken Bone in Osteomyelitis

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    Osteomyelitis is a debilitating infectious disease of the bone. It is predominantly caused by S. aureus and is associated with significant morbidity and mortality. It is characterised by weakened bones associated with progressive bone loss. Currently the mechanism through which either bone loss or bone destruction occurs in osteomyelitis patients is poorly understood. We describe here for the first time that the major virulence factor of S. aureus, protein A (SpA) binds directly to osteoblasts. This interaction prevents proliferation, induces apoptosis and inhibits mineralisation of cultured osteoblasts. Infected osteoblasts also increase the expression of RANKL, a key protein involved in initiating bone resorption. None of these effects was seen in a mutant of S. aureus lacking SpA. Complementing the SpA-defective mutant with a plasmid expressing spa or using purified protein A resulted in attachment to osteoblasts, inhibited proliferation and induced apoptosis to a similar extent as wildtype S. aureus. These events demonstrate mechanisms through which loss of bone formation and bone weakening may occur in osteomyelitis patients. This new information may pave the way for the development of new and improved therapeutic agents to treat this disease

    Expanding the diversity of mycobacteriophages: Insights into genome architecture and evolution

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    Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists. © 2011 Hatfull et al

    In vitro

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    Using an Ecological Ethics Framework to Make Decisions about the Relocation of Wildlife

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    Relocation is an increasingly prominent conservation tool for a variety of wildlife, but the technique also is controversial, even among conservation practitioners. An organized framework for addressing the moral dilemmas often accompanying conservation actions such as relocation has been lacking. Ecological ethics may provide such a framework and appears to be an important step forward in aiding ecological researchers and biodiversity managers to make difficult moral choices. A specific application of this framework can make the reasoning process more transparent and give more emphasis to the strong sentiments about non-human organisms held by many potential users. Providing an example of the application of the framework may also increase the appeal of the reasoning process to ecological researchers and biodiversity managers. Relocation as a conservation action can be accompanied by a variety of moral dilemmas that reflect the interconnection of values, ethical positions, and conservation decisions. A model that is designed to address moral dilemmas arising from relocation of humans provides/demonstrates/illustrates a possible way to apply the ecological ethics framework and to involve practicing conservationists in the overall decision-making process

    A contribuição dos estudos transculturais dos países latino-americanos e caribenhos para a revisão da CID-10: resultados preliminares The contribution of Latin American and Caribbean countries on culture bound syndromes studies for the ICD-10 revision: key findings from a working in progress

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    OBJETIVO: Esta revisão visa identificar as evidências dos estudos de países da América Latina e do Caribe para a inclusão das síndromes transculturais na versão da Classificação Internacional de Doenças para sua 11ª Edição. MÉTODO: Os estudos foram identificados nas bases do Medline, LILACS e EMBASE, no período de 1992 a 2008, e classificados segundo o tipo de estudo, tipo de transtorno, país e número de publicações por ano. RESULTADOS: Foram selecionadas e classificadas 163 publicações: 33 no Medline, 90 no EMBASE e 40 no LILACS. A percentagem das síndromes transculturais ("culture bound-syndrome") correspondeu a 9% no Medline, 12% no EMBASE e 2,5% no LILACS. Dos 15 estudos sobre síndromes transculturais, dois eram sobre "nervios e ataque de nervios", dois sobre "susto", quatro sobre a relação entre crenças religiosas, "feitiçaria", transe e apresentação dos transtornos mentais, um sobre proposta de uma nova categoria diagnóstica, três artigos teóricos e três sobre psicopatoplastia dos transtornos mentais. CONCLUSÃO: A escassez de estudos sobre síndromes transculturais pode ter ocorrido pela dificuldade em rastrear os estudos por problema de indexação das publicações, falta de interesse em publicar tais estudos em periódicos indexados e a dificuldade de acesso às publicações. Dentre os estudos identificados, não há uma evidência clara que aponte quais modificações são necessárias nas classificações diagnósticas atuais.<br>OBJECTIVE: This review aims to verify the scientific evidences for the inclusion of culture bound syndromes in the International Classification of Diseases towards its 11th edition based on studies from Latin American and Caribbean countries. METHOD: Studies were identified in Medline, LILACS and EMBASE databases for the period between 1992 and 2008, and then classified according to the type of study, to the mental disorder, country and number of publications per year. RESULTS: 163 studies were selected and classified: 33 in MedlLne, 90 in EMBASE e 40 in LILACS. The percentage of culture bound-syndrome corresponded to 9% in Medline, 12% in EMBASE e 2.5% in LILACS. Among fifteen studies on cultural bound syndromes, two were about "nervios and ataque de nervios", two about "susto", four about the relationship between religion beliefs, witchery, trance and mental disorders, one with a proposal for new diagnostic category, three about theoretic issues and three about the pathoplasty of mental disorders. CONCLUSION: The scarcity of studies on culture bound syndromes might be due to the indexation problems hindering the screening of studies; lack of interest on publishing such studies in indexed journals (publication bias) and due to difficulty to access them. There is no robust evidence identified among cross-cultural studies to recommend changes for International Classification of Diseases-11th edition

    The Effect of Surface Modifications upon the Mechanical Performance of Metals and Alloys

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    Meßergebnisse

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