642 research outputs found

    CODING AND CHARGING SPECIFICITIES OF sRNA's ISOLATED BY COUNTERCURRENT DISTRIBUTION

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    Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact

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    INTRODUCTION: The presence of Livestock Associated MRSA (LA-MRSA) in humans is associated with intensity of animal contact. It is unknown whether the presence of LA-MRSA is a result of carriage or retention of MRSA-contaminated dust. We conducted a longitudinal study among 155 veal farmers in which repeated nasal and throat swabs were taken for MRSA detection. Periods with and without animal exposure were covered. METHODS: Randomly, 51 veal calf farms were visited from June-December 2008. Participants were asked to fill in questionnaires (n = 155) to identify potential risk factors for MRSA colonisation. Nasal and throat swabs were repeatedly taken from each participant for approximately 2 months. Swabs were analysed for MRSA and MSSA by selective bacteriological culturing. Spa-types of the isolates were identified and a ST398 specific PCR was performed. Data were analyzed using generalized estimation equations (GEE) to allow for correlated observations within individuals. RESULTS: Mean MRSA prevalence was 38% in farmers and 16% in family members. Presence of MRSA in farmers was strongly related to duration of animal contact and was strongly reduced in periods with absence of animal contact (-58%). Family members, especially children, were more often carriers when the farmer was a carrier (OR = 2,

    The Skeletal Organic Matrix from Mediterranean Coral Balanophyllia europaea Influences Calcium Carbonate Precipitation

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    Scleractinian coral skeletons are made mainly of calcium carbonate in the form of aragonite. The mineral deposition occurs in a biological confined environment, but it is still a theme of discussion to what extent the calcification occurs under biological or environmental control. Hence, the shape, size and organization of skeletal crystals from the cellular level through the colony architecture, were attributed to factors as diverse as mineral supersaturation levels and organic mediation of crystal growth. The skeleton contains an intra-skeletal organic matrix (OM) of which only the water soluble component was chemically and physically characterized. In this work that OM from the skeleton of the Balanophyllia europaea, a solitary scleractinian coral endemic to the Mediterranean Sea, is studied in vitro with the aim of understanding its role in the mineralization of calcium carbonate. Mineralization of calcium carbonate was conducted by overgrowth experiments on coral skeleton and in calcium chloride solutions containing different ratios of water soluble and/or insoluble OM and of magnesium ions. The precipitates were characterized by diffractometric, spectroscopic and microscopic techniques. The results showed that both soluble and insoluble OM components influence calcium carbonate precipitation and that the effect is enhanced by their co-presence. The role of magnesium ions is also affected by the presence of the OM components. Thus, in vitro, OM influences calcium carbonate crystal morphology, aggregation and polymorphism as a function of its composition and of the content of magnesium ions in the precipitation media. This research, although does not resolve the controversy between environmental or biological control on the deposition of calcium carbonate in corals, sheds a light on the role of OM, which appears mediated by the presence of magnesium ions

    Characterization of human lymphocyte N -acetyltransferase and its relationship to the isoniazid acetylator polymorphism

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    Characterization of human lymphocyte N -acetyltransferase (NAT) for specific activity, substrate specificity, inhibition, pH optimum, apparent K m , kinetic mechanism, trypsin stability, freezing stability, and heat stability was carried out in rapid and slow isoniazid (INH) acetylators. There is a statistically significant difference in the heat stability of lymphocyte NAT from rapid and slow INH phenotypes. The lymphocyte enzyme from rapid INH acetylators is less heat stable than the lymphocyte enzyme from slow INH acetylators. This is an indication of a structural, possibly polymorphic, difference in lymphocyte NAT from the two acetylator phenotypes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44137/1/10528_2004_Article_BF00500122.pd

    Chairman's Introduction: Some Facts and Problems

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