85 research outputs found

    Ordered structure of the transcription network inherited from the yeast whole-genome duplication

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    <p>Abstract</p> <p>Background</p> <p>Gene duplication, a major evolutionary path to genomic innovation, can occur at the scale of an entire genome. One such "whole-genome duplication" (WGD) event among the Ascomycota fungi gave rise to genes with distinct biological properties compared to small-scale duplications.</p> <p>Results</p> <p>We studied the evolution of transcriptional interactions of whole-genome duplicates, to understand how they are wired into the yeast regulatory system. Our work combines network analysis and modeling of the large-scale structure of the interactions stemming from the WGD.</p> <p>Conclusions</p> <p>The results uncover the WGD as a major source for the evolution of a complex interconnected block of transcriptional pathways. The inheritance of interactions among WGD duplicates follows elementary "duplication subgraphs", relating ancestral interactions with newly formed ones. Duplication subgraphs are correlated with their neighbours and give rise to higher order circuits with two elementary properties: newly formed transcriptional pathways remain connected (paths are not broken), and are preferentially cross-connected with ancestral ones. The result is a coherent and connected "WGD-network", where duplication subgraphs are arranged in an astonishingly ordered configuration.</p

    Generalized Species Sampling Priors with Latent Beta reinforcements

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    Many popular Bayesian nonparametric priors can be characterized in terms of exchangeable species sampling sequences. However, in some applications, exchangeability may not be appropriate. We introduce a {novel and probabilistically coherent family of non-exchangeable species sampling sequences characterized by a tractable predictive probability function with weights driven by a sequence of independent Beta random variables. We compare their theoretical clustering properties with those of the Dirichlet Process and the two parameters Poisson-Dirichlet process. The proposed construction provides a complete characterization of the joint process, differently from existing work. We then propose the use of such process as prior distribution in a hierarchical Bayes modeling framework, and we describe a Markov Chain Monte Carlo sampler for posterior inference. We evaluate the performance of the prior and the robustness of the resulting inference in a simulation study, providing a comparison with popular Dirichlet Processes mixtures and Hidden Markov Models. Finally, we develop an application to the detection of chromosomal aberrations in breast cancer by leveraging array CGH data.Comment: For correspondence purposes, Edoardo M. Airoldi's email is [email protected]; Federico Bassetti's email is [email protected]; Michele Guindani's email is [email protected] ; Fabrizo Leisen's email is [email protected]. To appear in the Journal of the American Statistical Associatio

    An Evaluation of the Effectiveness of Risk Minimization Measures for Tigecycline in the European Union

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    Background: Risk minimization measures (RMM) were implemented from February 2011 in the European Union to address risks of superinfection, off-label use and lack of efficacy associated with tigecycline. The objective of this study was to evaluate RMM effectiveness by describing prescription patterns among adults and children treated with any dose of tigecycline for any indication pre- and post-RMM implementation; incidence proportions of superinfection and lack of efficacy among adults treated with approved doses of tigecycline for complicated intra-abdominal infection and complicated skin and soft tissue infection were also evaluated. Methods: This was an observational, retrospective chart-abstraction study, including charts from 777 patients (399 pre-RMM, 378 post-RMM) at 13 sites across Austria, Germany, Italy, Greece and the United Kingdom (UK). Potential superinfection and lack of efficacy cases among those using tigecycline for on-label indication, age, dose, and duration were adjudicated. The distribution of indications for tigecycline was analyzed overall (i.e. across both study periods) and stratified by study period. Numbers and incidence proportions of superinfection and lack of efficacy cases (potential and adjudicated) were calculated overall and by study period. Results: Off-label use (indication or age) decreased from 54.2% [95% confidence interval (95% CI): 49.0, 59.3%] pre-RMM to 35.7% (95% CI 30.4, 41.2%) post-RMM. Overall, 45.7% (95% CI 41.9, 49.5%) of patients were prescribed tigecycline off-label; the most commonly reported off-label indications were characterized as \u201cother\u201d (25.5%), hospital acquired pneumonia (8.2%), other pneumonia (6.3%), bacteremia (5.2%) and diabetic foot infection (1.5%). Across study periods, incidence proportions of definite or probable superinfection and lack of efficacy in adults treated for approved indications, authorized treatment doses and duration were 4.5% (95% CI 2.1, 8.4%) and 5.5% (95% CI 2.8, 9.7%), respectively. Conclusions: Off-label use of tigecycline decreased following RMM implementation. Overall incidence proportions of definite or probable superinfection and lack of efficacy were low. EU PAS register number: EUPAS3674

    NEW EARLY HOLOCENE SETTLEMENT IN CENTRAL ITALY: THE MESOLITHIC SITE OF CONTRADA PACE (MARCHE REGION)

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    Early Holocene hunter-gatherer settlements are spread throughout Italy and testify to the exploitation of very different landscapes. Nonetheless, their preservation state is not always exceptional. This is not the case for Contrada Pace, an archaeological site recently discovered on a terrace of the Chienti river in central-eastern Italy. This paper reports on the geomorphological, pedo-stratigraphic, and archaeological record of one of the most complete and well-preserved Early Mesolithic open-air sites in Italy and southern Europe. Micro-stratigraphic excavations extended over more than 500 square meters have exposed a buried paleosol with anthropogenic features, which contained thousand lithic artefacts and organic remains framed in the context of a primary forest. These findings appear clustered in different functional areas that yielded multiple structured features. The field evidence integrated by radiocarbon dating and archaeobotanical, archaeomalacological and zooarchaeological data allowed to propose a first interpretation of the general structure of the site and the most significant featuresThe archaeological excavation of the site was carried out by ArcheoLAB (Macerata, Italy) in the framework of construction activities promoted by the Province of Macerata and the Municipality of Tolentino. DV has received funding from the European Union's Horizon 2020 research and innovation programme (Grant Agreement number: 886476 - LiMPH - H2020-MSCA-IF-2019). The archaeobotanical study and 14C dates were funded by the European Research Council (ERC) as part of the Research and Innovation program of the European Community Horizon 2020 (HIDDEN FOODS no.639286 to EC)

    Epidemiology, Species Distribution, Antifungal Susceptibility and Outcome of Nosocomial Candidemia in a Tertiary Care Hospital in Italy

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    Candida is an important cause of bloodstream infections (BSI), causing significant mortality and morbidity in health care settings. From January 2008 to December 2010 all consecutive patients who developed candidemia at San Martino University Hospital, Italy were enrolled in the study. A total of 348 episodes of candidaemia were identified during the study period (January 2008–December 2010), with an incidence of 1,73 episodes/1000 admissions. Globally, albicans and non-albicans species caused around 50% of the cases each. Non-albicans included Candida parapsilosis (28.4%), Candida glabrata (9.5%), Candida tropicalis (6.6%), and Candida krusei (2.6%). Out of 324 evaluable patients, 141 (43.5%) died within 30 days from the onset of candidemia. C. parapsilosis candidemia was associated with the lowest mortality rate (36.2%). In contrast, patients with C. krusei BSI had the highest mortality rate (55.5%) in this cohort. Regarding the crude mortality in the different units, patients in Internal Medicine wards had the highest mortality rate (54.1%), followed by patients in ICU and Hemato-Oncology wards (47.6%)

    Ceftolozane/Tazobactam for Treatment of Severe ESBL-Producing Enterobacterales Infections: A Multicenter Nationwide Clinical Experience (CEFTABUSE II Study)

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    Background. Few data are reported in the literature about the outcome of patients with severe extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) infections treated with ceftolozane/tazobactam (C/T), in empiric or definitive therapy.Methods. A multicenter retrospective study was performed in Italy (June 2016-June 2019). Successful clinical outcome was defined as complete resolution of clinical signs/symptoms related to ESBL-E infection and lack of microbiological evidence of infection. The primary end point was to identify predictors of clinical failure of C/T therapy.Results. C/T treatment was documented in 153 patients: pneumonia was the most common diagnosis (n = 46, 30%), followed by 34 cases of complicated urinary tract infections (22.2%). Septic shock was observed in 42 (27.5%) patients. C/T was used as empiric therapy in 46 (30%) patients and as monotherapy in 127 (83%) patients. Favorable clinical outcome was observed in 128 (83.7%) patients; 25 patients were considered to have failed C/T therapy. Overall, 30-day mortality was reported for 15 (9.8%) patients. At multivariate analysis, Charlson comorbidity index &gt;4 (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-3.5; P = .02), septic shock (OR, 6.2; 95% CI, 3.8-7.9; P &lt; .001), and continuous renal replacement therapy (OR, 3.1; 95% CI, 1.9-5.3; P = .001) were independently associated with clinical failure, whereas empiric therapy displaying in vitro activity (OR, 0.12; 95% CI, 0.01-0.34; P &lt; .001) and adequate source control of infection (OR, 0.42; 95% CI, 0.14-0.55; P &lt; .001) were associated with clinical success.Conclusions. Data show that C/T could be a valid option in empiric and/or targeted therapy in patients with severe infections caused by ESBL-producing Enterobacterales. Clinicians should be aware of the risk of clinical failure with standard-dose C/T therapy in septic patients receiving CRRT

    Antifungal susceptibility of invasive yeast isolates in Italy: the GISIA3 study in critically ill patients

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    <p>Abstract</p> <p>Background</p> <p>Yeasts are a common cause of invasive fungal infections in critically ill patients. Antifungal susceptibility testing results of clinically significant fungal strains are of interest to physicians, enabling them to adopt appropriate strategies for empiric and prophylactic therapies. We investigated the antifungal susceptibility of yeasts isolated over a 2-year period from hospitalised patients with invasive yeast infections.</p> <p>Methods</p> <p>638 yeasts were isolated from the blood, central venous catheters and sterile fluids of 578 patients on general and surgical intensive care units and surgical wards. Etest strips and Sensititre panels were used to test the susceptibility of the isolates to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole in 13 laboratories centres (LC) and two co-ordinating centres (CC). The Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method was used at the CCs for comparison.</p> <p>Results</p> <p>Etest and Sensititre (LC/CC) MIC<sub>90 </sub>values were, respectively: amphotericin B 0.5/0.38, 1/1 mg/L; anidulafungin 2/1.5 and 1/1 mg/L; caspofungin 1/0.75 and 0.5/0.5 mg/L; fluconazole 12/8 and 16/16 mg/L; itraconazole 1/1.5, 0.5/0.5 mg/L; posaconazole 0.5 mg/L and voriconazole 0.25 mg/L for all. The overall MIC<sub>90 </sub>values were influenced by the reduced susceptibility of <it>Candida parapsilosis </it>isolates to echinocandins and a reduced or lack of susceptibility of <it>Candida glabrata </it>and <it>Candida krusei </it>to azoles, in particular fluconazole and itraconazole. Comparison of the LC and CC results showed good Essential Agreement (90.3% for Etest and 92.9% for Sensititre), and even higher Categorical Agreement (93.9% for Etest and 96% for Sensititre); differences were observed according to the species, method, and antifungal drug. No cross-resistance between echinocandins and triazoles was detected.</p> <p>Conclusions</p> <p>Our data confirm the different antifungal susceptibility patterns among species, and highlight the need to perform antifungal susceptibility testing of clinically relevant yeasts. With the exception of a few species (e.g. <it>C. glabrata </it>for azoles and <it>C. parapsilosis </it>for echinocandins), the findings of our study suggest that two of the most widely used commercial methods (Etest and Sensititre) provide valid and reproducible results.</p

    Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19

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    Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage
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