17 research outputs found

    Staphylococcus aureus Induces Eosinophil Cell Death Mediated by α-hemolysin

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    Staphylococcus aureus, a major human pathogen, exacerbates allergic disorders, including atopic dermatitis, nasal polyps and asthma, which are characterized by tissue eosinophilia. Eosinophils, via their destructive granule contents, can cause significant tissue damage, resulting in inflammation and further recruitment of inflammatory cells. We hypothesised that the relationship between S. aureus and eosinophils may contribute to disease pathology. We found that supernatants from S. aureus (SH1000 strain) cultures cause rapid and profound eosinophil necrosis, resulting in dramatic cell loss within 2 hours. This is in marked contrast to neutrophil granulocytes where no significant cell death was observed (at equivalent dilutions). Supernatants prepared from a strain deficient in the accessory gene regulator (agr) that produces reduced levels of many important virulence factors, including the abundantly produced α-hemolysin (Hla), failed to induce eosinophil death. The role of Hla in mediating eosinophil death was investigated using both an Hla deficient SH1000-modified strain, which did not induce eosinophil death, and purified Hla, which induced concentration-dependent eosinophil death via both apoptosis and necrosis. We conclude that S. aureus Hla induces aberrant eosinophil cell death in vitro and that this may increase tissue injury in allergic disease

    Some Dynamic Graphics for Spatial Data (with Multiple Attributes) in a GIS

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    . This paper discusses some multivariate exploratory spatial data analysis tools for detecting spatial dependence. The ideas explored are related to canonical correlation analysis and the graphical tools are related to the dynamic method called the grand tour. The work is implemented with a link between a Geographic Information System, ARC/INFO TM , and software for exploring multivariate data, XGobi. Keywords. canonical correlations, correlation tour, exploratory spatial data analysis, spatial dependence, spatial statistics 1 Introduction 1.1 Terminology and Notation for Spatial Data Spatial methods involve acknowledgement of the spatial location s of the attribute Z(s); s 2 D, where D is a subset of d-dimensional space. In what follows we shall mainly be interested in a multivariate attribute: Z(s) = (Z 1 (s); : : : ; Z p (s)) 0 : When we investigate how average values of Z vary with s, then we are considering the trend or large-scale variation in the attribute. One could t..

    First data about the preimaginal morphology of Austroscaeva occidentalis

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    Preimaginal morphology of Austroscaeva occidentalis (Shannon, 1927) is described for the first time, and the morphology of larvae and pupae of Dioprosopa clavata (Fabricius, 1794) is updated based on material obtained from captive rearing of wild females from Argentina and Venezuela, respectively. We describe the morphology of the third instar larva, head skeleton and puparium using optical microscopy, cryo-scanning and scanning electron microscope. The immature stages of both New World flower fly species are analysed and compared with the known preimaginal morphology of other taxa that belong to the evolutionary lineage of Eupeodes-Scaeva, where Austroscaeva Láska, Mazánek & Mengual, 2018, and Dioprosopa Hull, 1949, form a Neotropical radiation within, together with the genus Notosyrphus Vockeroth, 1969. Larvae of all members of this lineage have abdominal segments 5 and 6 with the tips of the locomotory prominences facing posteriorly, and the anal segment with a characteristic U-shaped grasping organ. Two other larval synapomorphies of this group of genera are the presence of metathoracic setae accompanying ventral sensilla, and the abdominal segments 1–7 with an extra lobe on each locomotory prominence. These two last characters cannot be assessed for Macrosyrphus Matsumura, 1917, and Lapposyrphus Dušek & Láska, 1967, based on published information on larval descriptions. Despite a similar colouration pattern of the fully grown larvae, larval morphology of A. occidentalis and D. clavata are quite distinct. The preimaginal morphology of A. occidentalis has a mixture of morphological characters from the taxa Scaeva Fabricius, 1805, Semiscaeva Kuznetzov, 1985, and Dioprosopa. The larvae of D. clavata show several unique diagnostic features, such as the presence of a slightly serrate outline due to the great development of the segmental spines and a pinnate ornamentation of the setae of its dorsal and dorsolateral sensilla. Regarding their biological cycle, the length of the preadult stages of A. occidentalis is almost 5 days longer than the length observed for D. clavata. In addition, new DNA barcodes are provided for A. occidentalis.Financial support was provided by the programme ‘Doctorar en el extranjero’ of the National University of Cuyo, Mendoza, Argentina

    Imunologia da hanseníase Immunology of leprosy

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    A hanseníase é doença crônica infecciosa que se caracteriza por apresentar formas clínicas contrastantes, que são dependentes da interação do bacilo com a resposta imune do hospedeiro. O estudo dos processos imunológicos torna-se fundamental para o entendimento dos mecanismos envolvidos na apresentação e no desenvolvimento da doença. Neste artigo, é revisada a imunopatogênese da hanseníase.<br>Leprosy is a chronic infectious disease characterized by contrasting clinical forms that are dependent on the interactions between the bacillus and the host immune response. Thus, the study of the immunological process is extremely relevant for the comprehension of the mechanisms involved in leprosy presentation and development. In this paper, the immunopathogenesis of leprosy is reviewed
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