130 research outputs found

    Hyperexpression of CDRs and HWP1 genes negatively impacts on Candida albicans virulence

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    C. albicans is a commensal organism present in the human microbiome of more than 60% of the healthy population. Transition from commensalism to invasive candidiasis may occur after a local or a general failure of host's immune system. This transition to a more virulent phenotype may reside either on the capacity to form hyphae or on an acquired resistance to antifungal drugs. Indeed, overexpression of genes coding drug efflux pumps or adhesins, cell wall proteins facilitating the contact between the fungus and the host, usually marks the virulence profile of invasive Candida spp. In this paper, we compare virulence of two clinical isolates of C. albicans with that of laboratory-induced resistant strains by challenging G. mellonella larvae with these pathogens along with monitoring transcriptional profiles of drug efflux pumps genes CDR1, CDR2, MDR1 and the adhesin genes ALS1 and HWP1. Although both clinical isolates were found resistant to both fluconazole and micafungin they were found less virulent than laboratory-induced resistant strains. An unexpected behavior emerged for the former clinical isolate in which three genes, CDR1, CDR2 and HWP1, usually correlated with virulence, although hyperexpressed, conferred a less aggressive phenotype. On the contrary, in the other isolate, we observed a decreased expression of CDR1, CDR2 and HWP1as well as of MDR1 and ALS1 that may be consistent with the less aggressive performance observed in this strain. These altered gene expressions might directly influence Candida virulence or they might be an epiphenomenon of a vaster rearrangement occurred in these strains during the challenge with the host's environment. An in-deepth comprehension of this scenario could be crucial for developing interventions able to counteract C. albicans invasiveness and lethality.C. albicans is a commensal organism present in the human microbiome of more than 60% of the healthy population. Transition from commensalism to invasive candidiasis may occur after a local or a general failure of host's immune system. This transition to a more virulent phenotype may reside either on the capacity to form hyphae or on an acquired resistance to antifungal drugs. Indeed, overexpression of genes coding drug efflux pumps or adhesins, cell wall proteins facilitating the contact between the fungus and the host, usually marks the virulence profile of invasive Candida spp. In this paper, we compare virulence of two clinical isolates of C. albicans with that of laboratory-induced resistant strains by challenging G. mellonella larvae with these pathogens along with monitoring transcriptional profiles of drug efflux pumps genes CDR1, CDR2, MDR1 and the adhesin genes ALS1 and HWP1. Although both clinical isolates were found resistant to both fluconazole and micafungin they were found less virulent than laboratory-induced resistant strains. An unexpected behavior emerged for the former clinical isolate in which three genes, CDR1, CDR2 and HWP1, usually correlated with virulence, although hyperexpressed, conferred a less aggressive phenotype. On the contrary, in the other isolate, we observed a decreased expression of CDR1, CDR2 and HWP1as well as of MDR1 and ALS1 that may be consistent with the less aggressive performance observed in this strain. These altered gene expressions might directly influence Candida virulence or they might be an epiphenomenon of a vaster rearrangement occurred in these strains during the challenge with the host's environment. An in-deepth comprehension of this scenario could be crucial for developing interventions able to counteract C. albicans invasiveness and lethality

    Perturbative and non-perturbative aspects of the two-dimensional string/Yang-Mills correspondence

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    It is known that YM_2 with gauge group SU(N) is equivalent to a string theory with coupling g_s=1/N, order by order in the 1/N expansion. We show how this results can be obtained from the bosonization of the fermionic formulation of YM_2, improving on results in the literature, and we examine a number of non-perturbative aspects of this string/YM correspondence. We find contributions to the YM_2 partition function of order exp{-kA/(\pi\alpha' g_s)} with k an integer and A the area of the target space, which would correspond, in the string interpretation, to D1-branes. Effects which could be interpreted as D0-branes are instead stricly absent, suggesting a non-perturbative structure typical of type 0B string theories. We discuss effects from the YM side that are interpreted in terms of the stringy exclusion principle of Maldacena and Strominger. We also find numerically an interesting phase structure, with a region where YM_2 is described by a perturbative string theory separated from a region where it is described by a topological string theory.Comment: 24 pages, 5 figure

    Risk Factors for Lung Cancer in the Province of Lecce: Results from the PROTOS Case–Control Study in Salento (Southern Italy)

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    In the province of Lecce (southern Italy), a higher incidence of lung cancer (LC) among men compared to regional and national data was reported. In a sub-area in the center of the province (cluster area), the incidence and mortality for LC was even higher. PROTOS is a case-control study aimed at investigating possible risk factors for LC in the province area. A total of 442 patients with LC and 1326 controls matched by sex and age living in the province of Lecce for at least 10 years were enrolled and georeferenced; they filled in a questionnaire with their personal information and exposures. For each risk factor, an Odds Ratio adjusted for all the other variables was calculated. The risk of LC increased with excessive use of alcohol in women, for those subjects with a family cancer history, for each increase in pack/year of cigarettes, for men more exposed considering the industrial district in the cluster area, and for those using pesticides in agriculture without wearing personal protective equipment. The higher incidence of adenocarcinoma in both sexes suggests that, in addition to cigarette smoking, concurrent exposures to other environmental, occupational, and life-style factors may play a role in increased cancer risk and should be more deeply explored

    Evaluation of Radon Exposure Risk and Lung Cancer Incidence/Mortality in South-Eastern Italy

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    Introduction: Radon and its decay products may cause substantial health damage after long-term exposure. The aim of the study was to perform a spatial analysis of radon concentration in the Salento peninsula, province of Lecce (South-eastern Italy) in order to better characterize possible risk for human health, with specific focus on lung cancer.Methods: Based on previous radon monitoring campaigns carried out in 2006 on behalf of the Local Health Authority (ASL Lecce) involving 419 schools and through the application of kriging estimation method, a radon risk map was obtained for the province of Lecce, in order to determine if areas with higher radon concentrations were overlapping with those characterized by the highest pulmonary cancer incidence and mortality rates.Results: According to our data, areas at higher radon concentrations seem to overlap with those characterized by the highest pulmonary cancer mortality and incidence rates, thus indicating that human exposure to radon could possibly enhance other individual or environmental pro-carcinogenic risk factors (i.e. cigarette smoking, air pollution and other exposures).Conclusions: The radon risk should be further assessed in the evaluation of the causes resulting in higher mortality and incidence rates for pulmonary cancer in Salento area vs Italian average national data. For these reasons, ASL Lecce in cooperation with ARPA Puglia and CNR-IFC has included the monitoring of individual indoor radon concentrations in the protocol of PROTOS case-control Study, aimed at investigating the role of different personal and environmental risk factors for lung cancer in Salento

    Preclinical development of a bispecific TNFα/IL-23 neutralising domain antibody as a novel oral treatment for inflammatory bowel disease.

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    Anti-TNFα and anti-IL-23 antibodies are highly effective therapies for Crohn's disease or ulcerative colitis in a proportion of patients. V56B2 is a novel bispecific domain antibody in which a llama-derived IL-23p19-specific domain antibody, humanised and engineered for intestinal protease resistance, V900, was combined with a previously-described TNFα-specific domain antibody, V565. V56B2 contains a central protease-labile linker to create a single molecule for oral administration. Incubation of V56B2 with trypsin or human faecal supernatant resulted in a complete separation of the V565 and V900 monomers without loss of neutralising potency. Following oral administration of V900 and V565 in mice, high levels of each domain antibody were detected in the faeces, demonstrating stability in the intestinal milieu. In ex vivo cultures of colonic biopsies from IBD patients, treatment with V565 or V900 inhibited tissue phosphoprotein levels and with a combination of the two, inhibition was even greater. These results support further development of V56B2 as an oral therapy for IBD with improved safety and efficacy in a greater proportion of patients as well as greater convenience for patients compared with traditional monoclonal antibody therapies

    Constraining Primordial Non-Gaussianity with High-Redshift Probes

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    We present an analysis of the constraints on the amplitude of primordial non-Gaussianity of local type described by the dimensionless parameter fNLf_{\rm NL}. These constraints are set by the auto-correlation functions (ACFs) of two large scale structure probes, the radio sources from NRAO VLA Sky Survey (NVSS) and the quasar catalogue of Sloan Digital Sky Survey Release Six (SDSS DR6 QSOs), as well as by their cross-correlation functions (CCFs) with the cosmic microwave background (CMB) temperature map (Integrated Sachs-Wolfe effect). Several systematic effects that may affect the observational estimates of the ACFs and of the CCFs are investigated and conservatively accounted for. Our approach exploits the large-scale scale-dependence of the non-Gaussian halo bias. The derived constraints on {fNLf_{\rm NL}} coming from the NVSS CCF and from the QSO ACF and CCF are weaker than those previously obtained from the NVSS ACF, but still consistent with them. Finally, we obtain the constraints on fNL=53±25f_{\rm NL}=53\pm25 (1σ1\,\sigma) and fNL=58±24f_{\rm NL}=58\pm24 (1σ1\,\sigma) from NVSS data and SDSS DR6 QSO data, respectively.Comment: 16 pages, 8 figures, 1 table, Accepted for publication on JCA

    High Yield Production Process for Shigella Outer Membrane Particles

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    Gram-negative bacteria naturally shed particles that consist of outer membrane lipids, outer membrane proteins, and soluble periplasmic components. These particles have been proposed for use as vaccines but the yield has been problematic. We developed a high yielding production process of genetically derived outer membrane particles from the human pathogen Shigella sonnei. Yields of approximately 100 milligrams of membrane-associated proteins per liter of fermentation were obtained from cultures of S. sonnei ΔtolR ΔgalU at optical densities of 30–45 in a 5 L fermenter. Proteomic analysis of the purified particles showed the preparation to primarily contain predicted outer membrane and periplasmic proteins. These were highly immunogenic in mice. The production of these outer membrane particles from high density cultivation of bacteria supports the feasibility of scaling up this approach as an affordable manufacturing process. Furthermore, we demonstrate the feasibility of using this process with other genetic manipulations e.g. abolition of O antigen synthesis and modification of the lipopolysaccharide structure in order to modify the immunogenicity or reactogenicity of the particles. This work provides the basis for a large scale manufacturing process of Generalized Modules of Membrane Antigens (GMMA) for production of vaccines from Gram-negative bacteria

    Solid Organ Transplantation During COVID-19 Pandemic: An International Web-based Survey on Resources’ Allocation

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    Background. Solid organ transplants (SOTs) are life-saving interventions, recently challenged by coronavirus disease 2019 (COVID-19). SOTs require a multistep process, which can be affected by COVID-19 at several phases. Methods. SOT-specialists, COVID-19-specialists, and medical ethicists designed an international survey according to CHERRIES guidelines. Personal opinions about continuing SOTs, safe managing of donors and recipients, as well as equity of resources' allocation were investigated. The survey was sent by e-mail. Multiple approaches were used (corresponding authors from Scopus, websites of scientific societies, COVID-19 webinars). After the descriptive analysis, univariate and multivariate ordinal regression analysis was performed. Results. There were 1819 complete answers from 71 countries. The response rate was 49%. Data were stratified according to region, macrospecialty, and organ of interest. Answers were analyzed using univariate- multivariate ordinal regression analysis and thematic analysis. Overall, 20% of the responders thought SOTs should not stop (continue transplant without restriction); over 70% suggested SOTs should selectively stop, and almost 10% indicated they should completely stop. Furthermore, 82% agreed to shift resources from transplant to COVID-19 temporarily. Briefly, main reason for not stopping was that if the transplant will not proceed, the organ will be wasted. Focusing on SOT from living donors, 61% stated that activity should be restricted only to "urgent"cases. At the multivariate analysis, factors identified in favor of continuing transplant were Italy, ethicist, partially disagreeing on the equity question, a high number of COVID-19- related deaths on the day of the answer, a high IHDI country. Factors predicting to stop SOTs were Europe except-Italy, public university hospital, and strongly agreeing on the equity question. Conclusions. In conclusion, the majority of responders suggested that transplant activity should be continued through the implementation of isolation measures and the adoption of the COVID-19-free pathways. Differences between professional categories are less strong than supposed
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