108 research outputs found

    NS3 Variability in Hepatitis C Virus Genotype 1A Isolates from Liver Tissue and Serum Samples of Treatment-NaĂŻve Patients with Chronic Hepatitis C.

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    Background: Hepatitis C virus (HCV) NS3 resistance-associated substitutions (RASs) reduce HCV susceptibility to protease inhibitors. Little is known about NS3 RASs in viral isolates from the liver of chronic hepatitis C (CHC) patients infected with HCV genotype-1a (G1a). Aim: The objective of this work was to study NS3 variability in isolates from the serum and liver of HCV-G1a-infected patients naĂŻve to direct-acting antivirals (DAAs). Methods: NS3 variability of HCV-G1a isolates from the serum and liver of 11 naĂŻve CHC patients, and from sera of an additional 20 naĂŻve CHC patients, was investigated by next-generation sequencing. Results: At a cutoff of 1%, NS3 RASs were detected in all the samples examined. At a cutoff of 15%, they were found in 54.5% (6/11) and 27.3% (3/11) of the paired liver and serum samples, respectively, and in 22.5% (7/31) of the overall serum samples examined. Twenty-six out of thirty-one (84%) patients showed NS3 variants with multiple RASs. Phylogenetic analysis showed that NS3 sequences clustered within 2 clades, with 10/31 (32.2%) patients infected by clade I, 15/31 (48.8%) by clade II, and 6/31 (19.3%) by both clades. Conclusions: Though the number of patients examined was limited, NS3 variants with RASs appear to be major components of both intrahepatic and circulating viral quasispecies populations in DAA-naĂŻve patients

    Protective Activity of Streptococcus pneumoniae Spr1875 Protein Fragments Identified Using a Phage Displayed Genomic Library

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    There is considerable interest in pneumococcal protein antigens capable of inducing serotype-independent immunoprotection and of improving, thereby, existing vaccines. We report here on the immunogenic properties of a novel surface antigen encoded by ORF spr1875 in the R6 strain genome. An antigenic fragment encoded by spr1875, designated R4, was identified using a Streptococcus pneumoniae phage displayed genomic library after selection with a human convalescent serum. Immunofluorescence analysis with anti-R4 antisera showed that Spr1875 was expressed on the surface of strains belonging to different serotypes. Moreover, the gene was present with little sequence variability in 27 different pneumococcal strains isolated worldwide. A mutant lacking Spr1875 was considerably less virulent than the wild type D39 strain in an intravenous mouse model of infection. Moreover, immunization with the R4 recombinant fragment, but not with the whole Spr1875 protein, induced significant protection against sepsis in mice. Lack of protection after immunization with the whole protein was related to the presence of immunodominant, non-protective epitopes located outside of the R4 fragment. In conclusion, our data indicate that Spr1875 has a role in pneumococcal virulence and is immunogenic. As the R4 fragment conferred immunoprotection from experimental sepsis, selected antigenic fragments of Spr1875 may be useful for the development of a pneumococcal protein-based vaccine

    Caratterizzazione biochimica e molecolare di glicoproteine di Cryptoccus neoformans

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    Dottorato di ricerca in scienze microbiologiche. 12. ciclo. A.a. 1998-99. Coordinatore F. Galdiero. Tutore G. TetiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    Gradual Exposure to Salinity Improves Tolerance to Salt Stress in Rapeseed (Brassica napus L.)

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    Soil salinity is considered one of the most severe abiotic stresses in plants; plant acclimation to salinity could be a tool to improve salt tolerance even in a sensitive genotype. In this work we investigated the physiological mechanisms underneath the response to gradual and prolonged exposure to sodium chloride in cultivars of Brassica napus L. Fifteen days old seedlings of the cultivars Dynastie (salt tolerant) and SY Saveo (salt sensitive) were progressively exposed to increasing soil salinity conditions for 60 days. Salt exposed plants of both cultivars showed reductions of biomass, size and number of leaves. However, after 60 days the relative reduction in biomass was lower in sensitive cultivar as compared to tolerant ones. An increase of chlorophylls content was detected in both cultivars; the values of the quantum eciency of PSII photochemistry (FPSII) and those of the electron transport rate (ETR) indicated that the photochemical activity was only partially reduced by NaCl treatments in both cultivars. Ascorbate peroxidase (APX) activity was higher in treated samples with respect to the controls, indicating its activation following salt exposure, and confirming its involvement in salt stress response. A gradual exposure to salt could elicit dierent salt stress responses, thus preserving plant vitality and conferring a certain degree of tolerance, even though the genotype was salt sensitive at the seed germination stage. An improvement of salt tolerance in B. napus could be obtained by acclimation to saline conditions

    The dual role of innate immunity during influenza

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    One of the distinguishing features of the 1918 pandemic is the occurrence of massive, potentially detrimental, activation of the innate immune system in critically ill patients. Whether this reflects an intrinsic capacity of the virus to induce an exaggerated inflammatory responses or its remarkable ability to reproduce in vivo is still open to debate. Tremendous progress has recently been made in our understanding of innate immune responses to influenza infection and it is now time to translate this knowledge into therapeutic strategies, particularly in view of the possible occurrence of future outbreaks caused by virulent strains. : We summarize here current knowledge of the mechanisms whereby the human body detects the presence of influenza virus infection, controls viral replication and repairs damaged tissue. We discuss the possibility of using this knowledge to treat patients with severe forms of the disease. Keywords: Toll-like receptors, RIG-I-like receptors, Interferon, Inflammasome, Inflammatio

    The Relevance of IL-1-Signaling in the Protection against Gram-Positive Bacteria

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    Previous studies performed using a model of group B streptococcus (GBS)-induced peritoneal inflammation indicate that the interleukin-1 receptor (IL-1R) family plays an important role in the innate host defense against this encapsulated Gram-positive bacteria. Since the role of IL-1-dependent signaling in peritoneal infections induced by other Gram-positive bacteria is unknown, in the present study we sought to investigate the contribution of IL-1R signaling in host defenses against Streptococcus pyogenes (group A streptococcus or GAS) or Staphylococcus aureus, two frequent and global human Gram-positive extracellular pathogens. We analyzed here the outcome of GAS or S. aureus infection in IL-1R-deficient mice. After inoculated intraperitoneal (i.p.) inoculation with group A Streptococcus or S. aureus, all the wild-type (WT) control mice survived the challenge, while, respectively, 63% or 50% of IL-1-defective mice died. Lethality was due to the ability of both bacterial species to replicate and disseminate to the target organs of IL-1R-deficient mice. Moreover, the experimental results indicate that IL-1 signaling promotes the production of leukocyte attractant chemokines CXCL-1 and CXCL-2 and recruitment of neutrophils to bacterial infection sites. Accordingly, the reduced neutrophil recruitment in IL-1R-deficient mice was linked with decreased production of neutrophil chemokines. Collectively, our findings indicate that IL-1 signaling, as previously showed in host defense against GBS, plays a fundamental role also in controlling the progression and outcome of GAS or S. aureus disease

    The Relevance of IL-1-Signaling in the Protection against Gram-Positive Bacteria

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    Previous studies performed using a model of group B streptococcus (GBS)-induced peritoneal inflammation indicate that the interleukin-1 receptor (IL-1R) family plays an important role in the innate host defense against this encapsulated Gram-positive bacteria. Since the role of IL-1-dependent signaling in peritoneal infections induced by other Gram-positive bacteria is unknown, in the present study we sought to investigate the contribution of IL-1R signaling in host defenses against Streptococcus pyogenes (group A streptococcus or GAS) or Staphylococcus aureus, two frequent and global human Gram-positive extracellular pathogens. We analyzed here the outcome of GAS or S. aureus infection in IL-1R-deficient mice. After inoculated intraperitoneal (i.p.) inoculation with group A Streptococcus or S. aureus, all the wild-type (WT) control mice survived the challenge, while, respectively, 63% or 50% of IL-1-defective mice died. Lethality was due to the ability of both bacterial species to replicate and disseminate to the target organs of IL-1R-deficient mice. Moreover, the experimental results indicate that IL-1 signaling promotes the production of leukocyte attractant chemokines CXCL-1 and CXCL-2 and recruitment of neutrophils to bacterial infection sites. Accordingly, the reduced neutrophil recruitment in IL-1R-deficient mice was linked with decreased production of neutrophil chemokines. Collectively, our findings indicate that IL-1 signaling, as previously showed in host defense against GBS, plays a fundamental role also in controlling the progression and outcome of GAS or S. aureus disease

    In Vivo Role of Two-Component Regulatory Systems in Models of Urinary Tract Infections

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    Two-component signaling systems (TCSs) are finely regulated mechanisms by which bacteria adapt to environmental conditions by modifying the expression of target genes. In bacterial pathogenesis, TCSs play important roles in modulating adhesion to mucosal surfaces, resistance to antibiotics, and metabolic adaptation. In the context of urinary tract infections (UTI), one of the most common types infections causing significant health problems worldwide, uropathogens use TCSs for adaptation, survival, and establishment of pathogenicity. For example, uropathogens can exploit TCSs to survive inside bladder epithelial cells, sense osmolar variations in urine, promote their ascension along the urinary tract or even produce lytic enzymes resulting in exfoliation of the urothelium. Despite the usefulness of studying the function of TCSs in in vitro experimental models, it is of primary necessity to study bacterial gene regulation also in the context of host niches, each displaying its own biological, chemical, and physical features. In light of this, the aim of this review is to provide a concise description of several bacterial TCSs, whose activity has been described in mouse models of UTI

    The Lègami/Legàmi Service—An Experience of Psychological Intervention in Maternal and Child Care during COVID-19

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    This study provides a descriptive analysis of the Lègami/Legàmi service, a free psychological support service in maternal and childcare, offered through the internet and by telephone that was initiated by the Italian Society of Pediatric Psychology (S.I.P.Ped.) during the COVID-19 medical emergency as an act of solidarity, first independently, and then in collaboration with the Italian Ministry of Health. This paper presents findings related to the “universe” of people who called the toll-free service, from the sociocultural characteristics of the users to the information collected by the professionals during the psychological pathways until human satisfaction was achieved. We provide a retrospective description of an experience that took place between April and June 2020,and which involved users of the maternal-infant area calling from the whole Italy. (1) Methods: The aims of this study were to investigate the configuration of the indicators identified and to detect the possible correlations between them in the sample. There were 193 users who took advantage of the Service, 160 of whom continued beyond the reception service; it is this group that we report the findings from here. The tool used was a form reporting access to care and interventions, and the resulting data underwent a content analysis and the indicators were subject to non-parametric statistical analysis to analyze differences and relationships. (2) Results: There were many correlations among the indicators that revealed a high prevalence of calls due to personal motivations and requests for support, which later allowed users to gain a greater understanding of the underlying problems they were facing. The professionals running the service noticed a prevalence of weaknesses attributable to the negative emotions of its users, alongside a presence of cognitive and relational resources. The professionals’ interventions, which can be characterized by a prevalence of social support, psychological rehabilitation, and psychoeducation, achieved outcomes of redefining users’ relationships with themselves and others. All of the service’s users have expressed a high level of satisfaction with it. (3) Discussion: Our results revealed the protective and transformative effects of the service for its users and the underlying importance of having an easily accessible psychological support system in place during emergencies, like the recent pandemic. In conditions like these, the great value of a remote support service should be noted, and despite its limitations, assures its own efficacy when a medical emergency precludes closer in-person forms of psychological assistance
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