56 research outputs found

    Polymerizing activity and regulation of group B Streptococcus pilus 2a sortase C1

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    Group B Streptococcus [GBS; Streptococcus agalactiae] is the leading cause of life-threatening diseases in newborn and is also becoming a common cause of invasive diseases in non-pregnant, elderly and immune-compromised adults. Pili, long filamentous fibers protruding from the bacterial surface, have been discovered in GBS, as important virulence factors and vaccine candidates. Gram-positive bacteria build pili on their cell surface via a class C sortase-catalyzed transpeptidation mechanism from pilin protein substrates. Despite the availability of several crystal structures, pilus-related C sortases remain poorly characterized to date and their mechanisms of transpeptidation and regulation need to be further investigated. The available three-dimensional structures of these enzymes reveal a typical sortase fold except for the presence of a unique feature represented by an N-terminal highly flexible loop, known as the “lid”. This region interacts with the residues composing the catalytic triad and covers the active site, thus maintaining the enzyme in an auto-inhibited state and preventing the accessibility to the substrate. It is believed that enzyme activation may occur only after lid displacement from the catalytic domain. In this work we provide the first direct evidence of the regulatory role of the lid, demonstrating that it is possible to obtain in vitro an efficient polymerization of pilin subunits using an active C sortase lid mutant carrying a single residue mutation in the lid region. Moreover, biochemical analyses of this recombinant mutant reveal that the lid confers thermodynamic and proteolytic stability to the enzyme. A further characterization of this sortase active mutant showed promiscuity in the substrate recognition, as it is able to polymerize different LPXTG-proteins in vitro

    Role of cardiac magnetic resonance in MINOCA of unclear etiology: A case report of a suspicious paradoxical coronary embolism

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    The acronym MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) refers to myocardial infarction with normal or near-normal coronary arteries on invasive angiography. The broad spectrum of pathological mechanisms responsible for myocardial injury in MINOCA makes defining the exact underlying etiology challenging. We report the uncommon case of an acute myocardial infarction with normal coronary arteries suggestive of MINOCA caused by paradoxical coronary embolism due to a wide right-to- left shunting through a patent fossa ovalis. Integrated multimodality imaging diagnostic work-up, including cardiac magnetic resonance, transesophageal contrast echocardiography, and transcranial contrast Doppler, has been crucial for identifying the most likely mechanism underlying MINOCA

    Lifestyles and socio-cultural factors among children aged 6-8 years from five Italian towns: The MAPEC-LIFE study cohort

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    Background: Lifestyles profoundly determine the quality of an individual’s health and life since his childhood. Many diseases in adulthood are avoidable if health-risk behaviors are identified and improved at an early stage of life. The aim of the present research was to characterize a cohort of children aged 6–8 years selected in order to perform an epidemiological molecular study (the MAPEC_LIFE study), investigate lifestyles of the children that could have effect on their health status, and assess possible association between lifestyles and socio-cultural factors. Methods: A questionnaire composed of 148 questions was administered in two different seasons to parents of children attending 18 primary schools in five Italian cities (Torino, Brescia, Pisa, Perugia and Lecce) to obtain information regarding the criteria for exclusion from the study, demographic, anthropometric and health information on the children, as well as some aspects on their lifestyles and parental characteristics. The results were analyzed in order to assess the frequency of specific conditions among the different seasons and cities and the association between lifestyles and socio-economic factors. Results: The final cohort was composed of 1,164 children (50.9 boys, 95.4% born in Italy). Frequency of some factors appeared different in terms of the survey season (physical activity in the open air, the ways of cooking certain foods) and among the various cities (parents’ level of education and rate of employment, sport, traffic near the home, type of heating, exposure to passive smoking, ways of cooking certain foods). Exposure to passive smoking and cooking fumes, obesity, residence in areas with heavy traffic, frequency of outdoor play and consumption of barbecued and fried foods were higher among children living in families with low educational and/or occupational level while children doing sports and consuming toasted bread were more frequent in families with high socio-economic level. Conclusions: The socio-economic level seems to affect the lifestyles of children enrolled in the study including those that could cause health effects. Many factors are linked to the geographical area and may depend on environmental, cultural and social aspects of the city of residence

    Neuromarketing: emotion and unconscious underlying the decision making process

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    openLa presente tesi di laurea svolge un'indagine approfondita nel campo del neuromarketing, per comprendere come il cervello dei consumatori reagisce agli stimoli di marketing e come queste reazioni influenzino le decisioni d'acquisto. Il lavoro si articola in tre parti principali. La prima sezione introduce il neuromarketing, analizzando la sua definizione, la sua storia evolutiva e le sue tecniche di applicazione. Nella seconda parte, la tesi esplora il concetto di "brand" e la sua importanza nel contesto del neuromarketing. Si analizza come le emozioni e il subconscio siano fondamentali e influenzino le decisioni d'acquisto dei consumatori. Nella terza parte, la ricerca prosegue con la creazione di un questionario volto a comprendere quanto le decisioni d'acquisto dei consumatori siano influenzate dal brand e quali siano le loro percezioni e preferenze riguardo ai brand e alle scelte d'acquisto

    what does marketing competencies mean

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    examines how companies can market their competencies to downstream partner

    Competence-based value framing for business-to-business customers

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    .The paper highlight how business suppliers set up processes allowing the translation of firm competencies in value for customer
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