294 research outputs found

    Dynamics and molecular evolution of HIV-1 strains in Sicily among antiretroviral na\uefve patients.

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    HIV-1 subtype B is the most frequent strain in Sicily. To date, there is no available data about the genetic diversity of HIV-1 viral strains circulating in Sicily among antiretroviral (ARV) na\uefve subjects and the role of immigration as potential determinant of evolutionary dynamics of HIV-1 molecular epidemiology. For this purpose, HIV-1 polymerase (pol) sequences obtained from 155 ARV na\uefve individuals from 2004 to 2009 were phylogenetically analysed. The overall rate of HIV-1 non-B infections was 31.0% (n = 48/155), increasing from 7.8% in 2004\u20132006 to 40.9% in 2009, and about one-third were identified as unique recombinant forms. CRF02_AG was the prevalent non-B clade (n = 28/48, 58.3%), while subtype C-related strains were responsible for about 30% HIV-1 infections. Non-B viruses strictly associated with heterosexual transmission (85.4%) and were mostly found among immigrants (77.1%). Phylogenetic analysis of non-B sequences found in foreign-born subjects was geographically correlated to the respective country of origin. Moreover, the detection of non-B viral variants in the autochthonous population may support an increasing genetic diversity in Sicily as well as a local circulation of HIV strains also uncommon in our country. In Sicily, HIV-1 epidemic is still mostly attributable to the B subtype. Nevertheless, migration and population movements are progressively introducing novel HIV-1 subtypes causing a continuous increase of HIV-1 molecular dynamic at local level. Molecular surveillance is needed to monitor the genetic evolution of HIV-1 epidemic

    A survey on knowledge and perceptions regarding head lice on a sample of teachers and students in primary schools of north and south of Italy

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    High rates of pediculosis are found in every part of the world. The age-range most affected is between 3 and 12 years. No-nit policies are ineffective in preventing infestations. On the other hand, misdiagnosis and overuse of pediculicides, increase resistance to treatment. Lack of information leads people to consider this kind of infestation to be associated to low social classes and immigrants. This research has been implemented to find out about the information level on pediculosis on a sample of students (722) and teachers (408) of some primary schools in northern and southern Italy, and to highlight the role of personal aspects such as age, gender, cultural level, geographical position which may influence this topic and, eventually, allow the use of the correct knowledge in developing appropriate procedures within the school district. Data was obtained through a questionnaire containing 21 multiple choice questions for the teachers and 14 for the students. Standard descriptive statistics were computed. ?2 tests were applied to highlight statistical association among observed variables; test for the difference of two proportions were applied to confirm significant differences among the observed proportions. The level of information for students seems to be, approximately, the same both for northern and southern Italy. There was a slight prevalence of correct answers from southern teachers, probably because the phenomenon of pediculosis has a positive trend of growth in the south. The number of correct answers was, for all, on average about 60.0%; a negative result in itself, considering the simplicity of the questions. Knowledge about the biology of the louse was virtually absent. The area of prevention showed lack of information and need for improvement. Most of the teachers believe that there are specific products that can prevent infestation by louse. Most of the teachers have information which does not come from scientific sources. Students receive some short and incomplete information from their parents. Deficiencies in teachers? knowledge indicate that they are inadequately equipped to manage lice infestation. Educational interventions with teachers and families and, as a consequence, with students should be taught at school to allow a correct understanding of the pediculosis, increasing the teachers? competence and, consequently, as soon as the infestation should manifest, a rapid alert of the Health Service so that proper treatment could be provided

    Electromagnetic response of LaO_0.94F_0.06FeAs: AC susceptibility and microwave surface resistance

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    We discuss on the electromagnetic response of a polycrystalline sample of LaO_0.94F_0.06FeAs exposed to DC magnetic fields up to 10 kOe. The low- and high-frequency responses have been investigated by measuring the AC susceptibility at 100 kHz and the microwave surface resistance at 9.6 GHz. At low as well as high DC magnetic fields, the susceptibility strongly depends on the amplitude of the AC driving field, highlighting enhanced nonlinear effects. The field dependence of the AC susceptibility exhibits a magnetic hysteresis that can be justified considering the intragrain-field-penetration effects on the intergrain critical current density. The microwave surface resistance exhibits a clockwise magnetic hysteresis, which cannot be justified in the framework of the critical-state models of the Abrikosov-fluxon lattice; it may have the same origin as that detected in the susceptibility.Comment: 8 pages, 4 embedded eps figures; Proceedings of the 9th EUCAS Conference (Dresden, Germany, September 13-17, 2009

    Staphylococcal cassette chromosome mec typing and meca sequencing in methicillin-resistant staphylococci from Algeria: A highly diversified element with new mutations in mecA

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    Genetic mechanisms of methicillin resistance are still relevant in staphylococci. The aims of this study are to assess the possible exchanges of staphylococcal cassette chromosome mec (SCCmec) among isolates of methicillin-resistant staphylococci (MRS) and to check for known or new mutations in mecA DNA. A total of 35 MRS non-repetitive isolates were recovered, including 20 Staphylococcus haemolyticus, 7 Staphylococcus aureus, 4 Staphylococcus sciuri, 2 Staphylococcus saprophyticus and 1 isolate each of Staphylococcus xylosus and Staphylococcus lentus. Only 16 of the 35 strains were assigned to known SCCmec types: 7 SCCmec VII, 6 SCCmec IV and 3 SCCmec III, with possible horizontal transfer of the SCCmec VII from methicillin-resistant S. haemolyticus to methicillin-susceptible S. aureus. mecA gene sequencing in ten selected isolates allowed description of nine punctual mutations, seven of which were reported for the first time. The most frequent mutation was G246E, identified in isolates of methicillin-resistant S. aureus, S. sciuri, S. saprophyticus and S. lentus. These results emphasized the high degree of genetic diversity of SCCmec element in MRS and describe new missense mutations in mecA, which might be important in understanding the evolution of methicillin and new b-lactam resistance

    Sorveglianza delle gastroenteriti da Norovirus in Italia: comparsa e diffusione della nuova variante GII.4 Sydney 2012

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    In the 2012-2013 winter season, global surveillance for norovirus circulation evidenced the onset of a new norovirus GII.4 variant, termed Sydney 2012. In Italy, ISGEV hospital-based surveillance revealed that this variant already circulated at low frequency in the winter season 2011-2012 and emerged definitively only in the late 2012. This lag-time pattern mirrors the findings reported elsewhere and suggests that the novel variant circulated at low prevalence before spreading globally

    Fine characterization of immunological mechanisms mediated by the major allergens of Parietaria judaica and hypoallergenic hybrid, rPjEDcys

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    Purpose: Allergy is a hypersensitivity disease IgE-mediated, affecting more than 25% of the population. The symptoms of IgE-mediated allergies reactions can be transiently ameliorated pharmacologically, but the only curative treatment of allergies is Allergen-Specific Immunotherapy (SIT). Recombinant hypoallergenic allergen derivatives with reduced allergenic activity have been engineered to reduce side effects during SIT. Parietaria judaica (Pj) pollen contains two major allergens belonging to the family of Lipid Tranfer Proteins (Par j 1 and Par j 2). By means of DNA recombinant technology, a hybrid hypoallergenic (PjEDcys), expressing disulphide bond variants of Par j 1 and Par j 2, was generated. The aim of this research project is to study the immunological mechanisms activated by the major allergens of Parietaria judaica, Par j 1 and Par j 2, and hypoallergenic hybrid rPjEDcys. Moreover, the project I am involved is trying to address the question whether this engineered hypoallergenic derivative can be a potential products for safer Allergen Specific Immunotherapy (SIT). Methods: Par j 1, Par j 2 and PjEDcys were produced as recombinant proteins. Human Peripheral Blood Mononuclear Cell (PBMC) from P. judaica allergic patients were stimulated in vitro with wild-type recombinant allergens and hybrid. PBMC proliferation assay, cytokine secretion assay, magnetic cell sorting of different subset of regulatory T cells, multiparametric flow cytometric analysis and molecular characterization using Real Time-PCR on sorted cells allow to study the biological properties of wild-type recombinant allergens and hybrid hypoallergenic derivate. Results: In vitro analysis suggested that PjEDcys have a reduced allergenity and maintained T cells reactivity. PBMC of P. judaica allergic patients stimulated in vitro with the hybrid and the wild-type recombinant allergens scored a percentage of proliferating CD4+ and CD56+ cell higher than unstimulated sample. Consistent with these data, cytokine secretion assay on CD4+ cells demonstrated that PBMC stimulation with rPjEDcys showed a percentage of IL-5 and IL-13 secreting T CD4+ cells lower than the wild-type allergens. Both rPjEDcys and wild-type stimulation promote the secretion of IFN- \u3b3 and IL-10 by T CD4+ cells. Finally whit the aim to study which subset of regulatory cells respond to wild-tipe allergens and hypoallergenic hybrid new experiment are setting. Discussion: In this experimental setting, the use of the major allergens of Pj and the hybrid polypeptides, rPjEDcys allows me to study the immunological mechanisms activated by the two different antigen stimulation and to investigate differences between the wild-type allergen and the hypoallergenic mutant rPjEDcys. Our data showed that CD4+ cells are clearly the predominant cell population proliferating in response to mixture of Par j 1 and Par j 2 allergens. The hypoallergenic derivate rPjEDcys retain the ability to stimulate CD4+ cells proliferation like the mixture of allergens (rPar j 1 and rPar j 2). Moreover these results highlighted a particular interesting datum; the mixture of allergens and the rPjEDcys hybrid showed the ability to stimulate an innate immune response, inducing CD56+ cells proliferative response. Cytokine secretion assay demonstrate that rPjEDcys reduce the secretion of IL-5 and IL-13, Th2 cytokines with a critical role in the development of allergy, compared to wild-type allergens. This may reflect the different biological function exerted by rPjEDcys. Conclusion: Collectivelly, our findings demonstrate that PjEDcys show a reduced allergenicity but maintained its immunogenicity and maybe it is also capable to regulate and redirect the immune response. These results suggest that PjEDcys represent a useful approach for immunotherapy of allergic disease

    Descriptive Epidemiology of Nasal Carriage of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Among Patients Admitted to Two Healthcare Facilities in Algeria

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    Aim: To evaluate nasal carriage rate and variables associated with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted in two healthcare facilities. Results: S. aureus was isolated from 159 (26%) of the enrolled patients. Methicillin-susceptible S. aureus was isolated from 150 (24.5%) patients, and MRSA was isolated from 9 (1.5%). Cancer and previous hospitalization were associated with a significantly higher frequency of nasal S. aureus carriage among the patients admitted to the general hospital and the nephrology department, respectively. MRSA isolates were heterogeneous with respect to their staphylococcal cassette chromosome mec element (SCCmec) type, sequence type (ST), and toxin genes (pvl and tst1) content. Four isolates were attributed with the ST80-MRSA-IV clone, which is known to be predominant in Algeria. Conclusions: This is the first assessment of S. aureus and MRSA nasal carriage and associated variables in Algeria. Our findings provide also a picture of the MRSA strains circulating in the community in this geographic area. They can be useful as a guide for implementing screening and control procedures against S. aureus/MRSA in the Algerian healthcare facilities

    Genetic heterogeneity and recombination in human type 2 astroviruses

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    Novel lineages of human astrovirus (HAstV) types 2, 2c, and 2d have been identified. Upon sequencing of the 3= end of the genome, the type 2c and 2d HAstVs were found to be open reading frame 1b (ORF1b)-ORF2 recombinant, with ORF1b being derived from type 3 and type 1 HAstVs, respectively. An ORF2 interlineage recombinant strain, 2c/2b, was also identified

    Ci8 short, a novel LPS-induced peptide from the ascidian Ciona intestinalis,modulates responses of the human immune system

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    The selective modulation of immunity is an emerging concept driven by the vast advances in our understanding of this crucial host defense system. Invertebrates have raised researchers’ interest as potential sources of new bioactive molecules owing to their antibacterial, anticancer and immunomodulatory activities. A LipoPolySaccharide (LPS) challenge in the ascidian Ciona intestinalis generates the transcript, Ci8 short, with cisregulatory elements in the 3′ UTR region that are essential for shaping innate immune responses. The derived amino acidic sequence in silico analysis showed specific binding to human Major Histocompatibility Complex (MHC) Class I and Class II alleles. The role of Ci8 short peptide was investigated in a more evolved immune system using human Peripheral Blood Mononuclear Cells (PBMCs) as in vitro model. The biological activities of this molecule include the activation of 70 kDa TCR ζ chain Associated Protein kinase (ZAP-70) and T Cell Receptor (TCR) Vβ oligo clonal selection on CD4+ T lymphocytes as well as increased proliferation and IFN-γ secretion. Furthermore Ci8 short affects CD4+/CD25high induced regulatory T cells (iTreg) subset selection which co-expressed the functional markers TGF-β1/Latency Associated Protein (LAP) and CD39/CD73. This paper describes a new molecule that modulates important responses of the human adaptive immune system

    An Analysis of the Neutralizing Antibodies against the Main SARS-CoV-2 Variants in Healthcare Workers (HCWs) Vaccinated against or Infected by SARS-CoV-2

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    : Although the anti-COVID-19 vaccination has proved to be an effective preventive tool, "breakthrough infections" have been documented in patients with complete primary vaccination courses. Most of the SARS-CoV-2 neutralizing antibodies produced after SARS-CoV-2 infection target the spike protein receptor-binding domain which has an important role in facilitating viral entry and the infection of the host cells. SARS-CoV-2 has demonstrated the ability to evolve by accumulating mutations in the spike protein to escape the humoral response of a host. The aim of this study was to compare the titers of neutralizing antibodies (NtAbs) against the variants of SARS-CoV-2 by analyzing the sera of recovered and vaccinated healthcare workers (HCWs). A total of 293 HCWs were enrolled and divided into three cohorts as follows: 91 who had recovered from SARS-CoV-2 infection (nVP); 102 that were vaccinated and became positive after the primary cycle (VP); and 100 that were vaccinated with complete primary cycles and concluded the follow-up period without becoming positive (VN). Higher neutralization titers were observed in the vaccinated subjects' arms compared to the nVP subjects' arms. Differences in neutralization titers between arms for single variants were statistically highly significant (p < 0.001), except for the differences between titers against the Alpha variant in the nVP and in VP groups, which were also statistically significant (p < 0.05). Within the nVP group, the number of subjects with an absence of neutralizing antibodies was high. The presence of higher titers in patients with a complete primary cycle compared to patients who had recovered from infection suggested the better efficacy of artificial immunization compared to natural immunization, and this further encourages the promotion of vaccination even in subjects with previous infections
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