133 research outputs found

    The thickness of the ground: four micro-stories on the project of the open urban ground floor in SĂŁo Paulo from 1892 until nowadays

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    The research is framed thematically in the field of urban open space design in the contemporary city, mainly dealing with the system of urban voids. The hypothesis from which the search starts is that it is in the thickness of the ground of the city that architecture, as a spatial configuration, can operate in a more effective and incisive way to the city project. Consequently we also want to investigate the possibility of related project devices. In order to do that, we take São Paulo as the field of enquiry, because the two meanings associated to the expression “the thickness of the ground” are particularly relevant in this city

    Increased Neutrophil Extracellular Trap-Mediated Staphylococcus aureus Clearance Through Inhibition of Nuclease Activity by Clindamycin and Immunoglobulin

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    The Gram-positive human pathogen Staphylococcus aureus causes a variety of human diseases such as skin infections, pneumonia, and endocarditis. The micrococcal nuclease Nuc1 is one of the major S. aureus virulence factors and allows the bacterium to avoid neutrophil extracellular trap (NET)-mediated killing. We found that addition of the protein synthesis inhibitor clindamycin to S. aureus LAC cultures decreased nuc1 transcription and subsequently blunted nuclease activity in a molecular beacon-based fluorescence assay. We also observed reduced NET degradation through Nuc1 inhibition translating into increased NET-mediated clearance. Similarly, pooled human immunoglobulin specifically inhibited nuclease activity in a concentration-dependent manner. Inhibition of nuclease activity by clindamycin and immunoglobulin enhanced S. aureus clearance and should be considered in the treatment of S. aureus infection

    Evaluation of a kDNA-Based qPCR Assay for the Detection and Quantification of Old World Leishmania Species

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    none10noThe parasite protozoan Leishmania, the causative agent of leishmaniasis, includes two subgenera of medical interest: Leishmania (Leishmania) and Leishmania (Viannia). Parasite species detection and characterization is crucial to choose treatment protocols and to monitor the disease evolution. Molecular approaches can speed up and simplify the diagnostic process. In particular, several molecular assays target the mitochondrial DNA minicircle network (kDNA) that characterizes the Leishmania genus. We previously proposed a qPCR assay targeting kDNA, followed by high resolution melt (HRM) analysis (qPCR-ML) to distinguish L. (L.) infantum and L. (L.) amazonensis from L. Viannia species. Successively, this assay has been integrated with other qPCR assays, to differentiate L. (L.) infantum, L. (L.) amazonensis and L. (L.) mexicana. In this work, we tested the applicability of our qPCR-ML assay on L. (L.) donovani, L. (L.) major, L. (L.) tropica and L. (L.) aethiopica, showing that the qPCR-ML assay can also amplify Old World species, different from L. (L.) infantum, with good quantification limits (1 Ă— 10-4-1 Ă— 10-6 ng/pcr tube). Moreover, we evaluated 11 L. (L.) infantum strains/isolates, evidencing the variability of the kDNA minicircle target molecules among the strains/isolates of the same species, and pointing out the possibility of quantification using different strains as reference. Taken together, these data account for the consideration of qPCR-ML as a quantitative pan-Leishmania assay.openCeccarelli, Marcello; Buffi, Gloria; Diotallevi, Aurora; Andreoni, Francesca; Bencardino, Daniela; Vitale, Fabrizio; Castelli, Germano; Bruno, Federica; Magnani, Mauro; Galluzzi, LucaCeccarelli, Marcello; Buffi, Gloria; Diotallevi, Aurora; Andreoni, Francesca; Bencardino, Daniela; Vitale, Fabrizio; Castelli, Germano; Bruno, Federica; Magnani, Mauro; Galluzzi, Luc

    Coiled-coil irregularities of the M1 protein structure promote M1-fibrinogen interaction and influence group A Streptococcus host cell interactions and virulence

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    Group A Streptococcus (GAS) is a human pathogen causing a wide range of mild to severe and life-threatening diseases. The GAS M1 protein is a major virulence factor promoting GAS invasiveness and resistance to host innate immune clearance. M1 displays an irregular coiled-coil structure, including the B-repeats that bind fibrinogen. Previously, we found that B-repeat stabilisation generates an idealised version of M1 (M1*) characterised by decreased fibrinogen binding in vitro. To extend these findings based on a soluble truncated version of M1, we now studied the importance of the B-repeat coiled-coil irregularities in full length M1 and M1* expressed in live GAS and tested whether the modulation of M1-fibrinogen interactions would open up novel therapeutic approaches. We found that altering either the M1 structure on the GAS cell surface or removing its target host protein fibrinogen blunted GAS virulence. GAS expressing M1* showed an impaired ability to adhere to and to invade human endothelial cells, was more readily killed by whole blood or neutrophils and most importantly was less virulent in a murine necrotising fasciitis model. M1-mediated virulence of wild-type GAS was strictly dependent on the presence and concentration of fibrinogen complementing our finding that M1-fibrinogen interactions are crucial for GAS virulence. Consistently blocking M1-fibrinogen interactions by fragment D reduced GAS virulence in vitro and in vivo. This supports our conclusion that M1-fibrinogen interactions are crucial for GAS virulence and that interference may open up novel complementary treatment options for GAS infections caused by the leading invasive GAS strain M

    The group A Streptococcus interleukin-8 protease SpyCEP promotes bacterial intracellular survival by evasion of autophagy

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    Autophagy serves an innate immune function in defending the host against invading bacteria, including group A Streptococcus (GAS). Autophagy is regulated by numerous host proteins, including the endogenous negative regulator calpain, a cytosolic protease. Globally disseminated serotype M1T1 GAS strains associated with high invasive disease potential express numerous virulence factors and resist autophagic clearance. Upon in vitro infection of human epithelial cell lines with representative wild-type GAS M1T1 strain 5448 (M1.5448), we observed increased calpain activation linked to a specific GAS virulence factor, the IL-8 protease SpyCEP. Calpain activation inhibited autophagy and decreased capture of cytosolic GAS in autophagosomes. In contrast, the serotype M6 GAS strain JRS4 (M6.JRS4), which is highly susceptible to host autophagy-mediated killing, expresses low levels of SpyCEP and does not activate calpain. Overexpression of SpyCEP in M6.JRS4 stimulated calpain activation, inhibited autophagy and significantly decreased bacterial capture in autophagosomes. These paired loss- and gain-of-function studies reveal a novel role for the bacterial protease SpyCEP in enabling GAS M1 evasion of autophagy and host innate immune clearance

    Development and Application of a High Resolution Melt (HRM) based test for the Rapid Screening of Leishmania infantum Genotypes

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    INTRODUCTION Leishmaniasis includes anthropo zoonotic infectious diseases caused by a protozoan of the Leishmania genus, associated with different clinical manifestations, affecting both humans and other vertebrates, including dogs The Mediterranean basin, including Italy, is considered an endemic area for both visceral and cutaneous leishmaniasis caused by L infantum The multi locus enzyme electrophoresis ( based on the electrophoretic mobility of several enzymes from promastigotes cultures, is considered the reference method for parasite typing Through this method, about 45 L infantum zymodemes (also termed MON) have been identified in humans in the Mediterranean basin 1 Among these, L infantum MON 1 is the most widespread, representing about 70 of all identified strains In Italy, canine infections showed a high prevalence of MON 1 91 with the remaining composed almost exclusively of MON 72 2 Since MLEE technique is cumbersome, time consuming and requires parasites isolation, several biomolecular approaches have been developed In particular, we identified the SNP 390 T>G in malic enzyme ( gene as a potential marker to differentiate the most common L infantum genotype, i e 390 T (corresponding to zymodemes MON 1 72 201 from all others. AIMS This study aimed to develop a Rapid Genotype Screening ( assay for L infantum genetic characterization in clinical samples using high resolution melt ( analysis, exploiting the polymorphism 390 T>G in the ME gene

    Recent transmission clustering of HIV-1 C and CRF17_BF strains characterized by NNRTI-related mutations among newly diagnosed men in central Italy

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    Increased evidence of relevant HIV-1 epidemic transmission in European countries is being reported, with an increased circulation of non-B-subtypes. Here, we present two recent HIV-1 non-B transmission clusters characterized by NNRTI-related amino-acidic mutations among newly diagnosed HIV-1 infected men, living in Rome (Central-Italy)

    Presto-Color: A Photometric Survey Cadence for Explosive Physics and Fast Transients

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    We identify minimal observing cadence requirements that enable photometric astronomical surveys to detect and recognize fast and explosive transients and fast transient features. Observations in two different filters within a short time window (e.g., g-and-i, or r-and-z, within 1.5 hr) are desirable for this purpose. Such an observing strategy delivers both the color and light curve evolution of transients on the same night. This allows the identification and initial characterization of fast transient—or fast features of longer timescale transients—such as rapidly declining supernovae, kilonovae, and the signatures of SN ejecta interacting with binary companion stars or circumstellar material. Some of these extragalactic transients are intrinsically rare and generally all hard to find, thus upcoming surveys like the Large Synoptic Survey Telescope (LSST) could dramatically improve our understanding of their origin and properties. We colloquially refer to such a strategy implementation for the LSST as the Presto-Color strategy (rapid-color). This cadence's minimal requirements allow for overall optimization of a survey for other science goals

    Analysis of the Relationship between Road Accidents and Psychophysical State of Drivers through Wearable Devices

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    A driver's behavior and their psychophysical state are the most common causes of road accidents. The research presented in the paper proposes a method that allows the identification of highly dangerous road stretches/intersections in advance, based on the localization of stressful/relaxing situations measured on drivers. These were measured through the collection of physiological parameters using wearable devices. A correlation between stressful/relaxing situations and locations with high accident rates, based on a historical statistical database (black spots), was investigated. A series of driving tests was conducted in the city of Milan. The first set was mostly oriented to the research and validation of the parameters related to the driver's psychophysical state. Subsequent tests allowed the definition of a correlation between black spots and relaxing/stressful areas. The results showed that the most stressful areas for drivers fell mainly within those with high accident rates. Furthermore, 80% of the most dangerous zones of the route were identified using this method, thus confirming the validity of the approach as a support tool for a priori preventive analysis for road safety. The wearable devices allowed the study and the integration of specific elements relating to human behavior in the field of road safety, which typically involves a technical-engineering approach

    Development and application of a MLST panel for the identification of informative polymorphisms in Leishmania infantum strains in the Mediterranean region

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    Background. Leishmaniasis is a zoonotic disease endemic in the Mediterranean region, where the causative agent of human and canine infection is Leishmania infantum. The spread of leishmaniasis is associated with population movements, ecology of phlebotomine vectors, and reservoir host. We used multilocus sequence typing (MLST) to explore the genetic variability of L. infantum strains in the Mediterranean region, including the borderline territory of Pantelleria island, and identify informative polymorphisms for rapid identification of genotypes through high-resolution melt (HRM)-based assays. Material and Methods. A customized sequencing panel targeting 14 housekeeping genes was designed and MLST analysis was performed using the Ion Torrent S5 on 9 L. infantum strains/isolates: 5 canine isolates (3 from Pantelleria Island and 2 from central Italy), and 4 human isolates/strains from Tunisia, France, central and southern Italy. MLST results and in silico analysis of sequences available in Genbank allowed to select two informative polymorphisms on ME and GPI genes (390T/G and 1834A/G, respectively) used to develop two HRM-based assays for fast screening of 28 clinical samples. Results. The MLST analysis identified a single L. infantum clonal complex regardless of the geographic origin or host (human or canine), except for the human isolate from central Italy that showed polymorphisms in 11 out of 14 housekeeping genes, and clustered independently in a molecular phylogenetic analysis. Successively, the screening through HRM-based assays of 28 clinical samples from central/south Italy and Pantelleria island allowed to identify 6 diploid sequence types (DSTs). Interestingly, the sequence type 390T/1834A was found only in Pantelleria island (prevalence 75%). Conclusion. This study represents a description of the genetic variability of L. infantum through a first approach based on MLST and then by HRM analysis on selected polymorphisms. The HRM assays could be used as fast and cheap tools for epidemiological surveillance of L. infantum
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