106 research outputs found

    Influence of aquatic microorganisms on Legionella pneumophila survival

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    The ability of aquatic bacteria Pseudomonas fluorescens SSD (Ps-D) and Pseudomonas putida SSC (Ps-C) to support the persistence of Legionella pneumophila (Lp-1) in an artificial water microcosm was investigated for 42 day, at two different incubation temperatures. At 4 °C, individually suspended Lp-1 was no longer detectable just after 24 hours, while in co-cultures with Pseudomonas, Lp1 showed a better survival capability. At 30 °C, Lp-1 alone displayed high survival rates over the entire period of observation. When Lp-1 was inoculated with Ps-C and Ps-D, its count showed a marked decrease, followed by a gradual and costant decline

    Castleman's disease in childhood: report of three cases and review of the literature

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    Castleman's disease (CD) is a rare, localized or generalized, lymphoproliferative disorder with a frequent mediastinal location, but possible in any lymph node or extra nodal site. It usually appears in young adults whilst it rarely occurs in childhood. There are only about 100 pediatric cases published, five of them in Italy. We report 3 cases of localized Castleman's disease, investigated in our Department in a 3 years period and reviewed the literature

    Ants Discriminate Between Different Hydrocarbon Concentrations

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    Social insects typically discriminate nestmates from non-nestmates using colony-specific blends of cuticular hydrocarbons, which may be considered as a chemical label. Within a species, the cuticular profile shows approximately the same qualitative set of compounds, although these differ quantitatively among colonies. Thus, the relative proportions of particular hydrocarbons may be higher in individuals of one colony compared to those of another (conspecific) colony. Social insects must perceive these differences in ratios in order to efficiently recognize non-nestmates. However, little is known about the underlying perceptual mechanisms. Here we investigated whether ants can discriminate between different doses of individual linear or methyl-branched hydrocarbons. We used the ant Camponotus aethiops as our study organism and differential conditioning of the maxilla-labium extension response as the experimental procedure, to test olfactory discrimination between two concentrations of the same compound (one rewarded and the other punished), using large (wide range, 1:100) and small differences (narrow range, 1:10) in hydrocarbon concentrations. Ants discriminated well between wide-range concentrations of the same compound, but showed asymmetric generalization between narrow-range concentrations. These results indicate that a certain differential in hydrocarbon concentration is essential for efficient discrimination

    Impiego dell'elettroforesicapillare per la caratterizzazione di microrganismi: l'analisi di ceppi di Saccharomyces cerevisiae

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    La possibilità di analizzare e determinare microrganismi, quali batteri e lieviti, in maniera rapida e riproducibile, suscita notevole interesse scientifico data la loro versatilità nel campo della ricerca e dell’industria. Rispetto alle classiche tecniche impiegate in microbiologia, i metodi basati sull’elettroforesi capillare appaiono a tutt'oggi alquanto promettenti poiché in grado non solo di separare con elevata efficienza molecole, ma anche particelle colloidali e quindi cellule. In particolari condizioni, infatti, le cellule microbiche evidenziano in superficie una propria carica netta, grazie alla composizione della loro parete cellulare, e conseguentemente si comportano alla stregua dei colloidi [1,2] il ché rende possibile la loro analisi elettroforetica [2-4]. Nella presente attività di ricerca è stato messo a punto un originale metodo di analisi basato su elettroforesi capillare con rivelazione a diode array applicato alla caratterizzazione di ceppi di lievito Saccharomyces cerevisiae. L'implementazione della metodica ha previsto l'ottimizzazione di una serie di parametri elettroforetici quali ad es. la viscosità del tampone di corsa, il volume di campione e l’intensità del campo elettrico applicato. Successivamente si è focalizzato l’interesse sullo studio del comportamento elettroforetico di diversi ceppi di Saccharomyces cerevisiae cresciuti in terreno liquido YPD (Yeast extract, Peptone, D-glucose). Lo studio ha evidenziato una variabilità significativa dei profili elettroforetici, imputata alle differenti velocità di crescita di ciascun ceppo. In particolare, la crescita del ceppo selvaggio 4LBI3 ha evidenziato, inoltre, che esiste una relazione tra il profilo elettroforetico e la fase di crescita in cui si trova la popolazione cellulare esaminata. L’analisi delle dimensioni cellulari mediante microscopia ottica ha evidenziato infine una correlazione tra il profilo elettroforetico del campione e l’effettiva eterogeneità dimensionale della popolazione cellulare analizzata. I risultati sperimentali ottenuti dimostrano la validità dell’elettroforesi capillare per lo studio delle dinamiche di crescita dei lieviti e ne incoraggiano una futura applicazione per analisi quantitative anche di altre specie microbiche. [1] Radko S.P., Chrambach A., Electrophoresis, (2002) 23: pp. 1957-1972 [2] Rodriguez M.A., Armstrong D.W., J. of Chromatography B, 800, 7 (2004). [3] Armstrong D.W., Girod L.H., Rodriguez M.A. et al., Analy. Chem., 74, 5523 (2002). [4] Armstrong D.W., Schulte G., Schneiderheinze J.M., Westenberg D.J., Anal. Chem., 71, 5465 (1999)

    Palliative splenic irradiation in primary and post PV/ET myelofibrosis: outcomes and toxicity of three radiation schedules

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    Splenectomy and splenic irradiation (SI) are the sole treatment modalities to control drug resistant splenomegaly in patients with myelofibrosis (MF). SI has been used in poor surgical candidates but optimal total dose and fractionation are unclear. We retrospectively reviewed 14 MF patients with symptomatic splenomegaly. Patients received a median of 10 fractions in two weeks. Fraction size ranged from 0.2–1.4 Gy, and total dose varied from 2–10.8 Gy per RT course. Overall results indicate that 81.8% of radiation courses achieved a significant spleen reduction. Splenic pain relief and gastrointestinal symptoms reduction were obtained in 94% and 91% of courses, respectively. Severe cytopenias occurred in 13% of radiation courses. Furthermore patients were divided in three groups according to the radiation dose they received: 6 patients in the low-dose group (LDG) received a normalized dose of 1.67 Gy; 4 patients in the intermediate-dose group (IDG) received a normalized dose 4.37 Gy; the remaining 4 patients in the high-dose group (HDG) received a normalized dose of 9.2 Gy. Subgroup analysis showed that if no differences in terms of treatment efficacy were seen among dose groups, hematologic toxicity rates distributed differently. Severe cytopenias occurred in 50% of courses in the HDG, and in the 14.3% and in 0% of the IDG and LDG, respectively. Spleen reduction and pain relief lasted for a median of 5.5 months in all groups. Due to the efficacy and tolerability of the low-dose irradiation 4 patients from the LDG and IDG were retreated and received on the whole 12 RT courses. Multiple retreatments did not show decremental trends in terms of rates of response to radiation nor in terms of duration of clinical response. Moreover, retreatment courses did not cause an increased rate of adverse effects and none of the retreated patients experienced severe hematologic toxicities. The average time of clinical benefit in retreated patients was much longer (21 months, range 44–10) than patients who were not retreated (5.75 months, range 3–6)

    Minimally invasive vs. open segmental resection of the splenic flexure for cancer: a nationwide study of the Italian Society of Surgical Oncology-Colorectal Cancer Network (SICO-CNN)

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    Background Evidence on the efficacy of minimally invasive (MI) segmental resection of splenic flexure cancer (SFC) is not available, mostly due to the rarity of this tumor. This study aimed to determine the survival outcomes of MI and open treatment, and to investigate whether MI is noninferior to open procedure regarding short-term outcomes. Methods This nationwide retrospective cohort study included all consecutive SFC segmental resections performed in 30 referral centers between 2006 and 2016. The primary endpoint assessing efficacy was the overall survival (OS). The secondary endpoints included cancer-specific mortality (CSM), recurrence rate (RR), short-term clinical outcomes (a composite of Clavien-Dindo > 2 complications and 30-day mortality), and pathological outcomes (a composite of lymph nodes removed >= 12, and proximal and distal free resection margins length >= 5 cm). For these composites, a 6% noninferiority margin was chosen based on clinical relevance estimate. Results A total of 606 patients underwent either an open (208, 34.3%) or a MI (398, 65.7%) SFC segmental resection. At univariable analysis, OS and CSM were improved in the MI group (log-rank test p = 0.004 and Gray's tests p = 0.004, respectively), while recurrences were comparable (Gray's tests p = 0.434). Cox multivariable analysis did not support that OS and CSM were better in the MI group (p = 0.109 and p = 0.163, respectively). Successful pathological outcome, observed in 53.2% of open and 58.3% of MI resections, supported noninferiority (difference 5.1%; 1-sided 95%CI - 4.7% to infinity). Successful short-term clinical outcome was documented in 93.3% of Open and 93.0% of MI procedures, and supported noninferiority as well (difference - 0.3%; 1-sided 95%CI - 5.0% to infinity). Conclusions Among patients with SFC, the minimally invasive approach met the criterion for noninferiority for postoperative complications and pathological outcomes, and was found to provide results of OS, CSM, and RR comparable to those of open resection

    COVID-19 Severity in Multiple Sclerosis: Putting Data Into Context

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    Background and objectives: It is unclear how multiple sclerosis (MS) affects the severity of COVID-19. The aim of this study is to compare COVID-19-related outcomes collected in an Italian cohort of patients with MS with the outcomes expected in the age- and sex-matched Italian population. Methods: Hospitalization, intensive care unit (ICU) admission, and death after COVID-19 diagnosis of 1,362 patients with MS were compared with the age- and sex-matched Italian population in a retrospective observational case-cohort study with population-based control. The observed vs the expected events were compared in the whole MS cohort and in different subgroups (higher risk: Expanded Disability Status Scale [EDSS] score > 3 or at least 1 comorbidity, lower risk: EDSS score ≤ 3 and no comorbidities) by the χ2 test, and the risk excess was quantified by risk ratios (RRs). Results: The risk of severe events was about twice the risk in the age- and sex-matched Italian population: RR = 2.12 for hospitalization (p < 0.001), RR = 2.19 for ICU admission (p < 0.001), and RR = 2.43 for death (p < 0.001). The excess of risk was confined to the higher-risk group (n = 553). In lower-risk patients (n = 809), the rate of events was close to that of the Italian age- and sex-matched population (RR = 1.12 for hospitalization, RR = 1.52 for ICU admission, and RR = 1.19 for death). In the lower-risk group, an increased hospitalization risk was detected in patients on anti-CD20 (RR = 3.03, p = 0.005), whereas a decrease was detected in patients on interferon (0 observed vs 4 expected events, p = 0.04). Discussion: Overall, the MS cohort had a risk of severe events that is twice the risk than the age- and sex-matched Italian population. This excess of risk is mainly explained by the EDSS score and comorbidities, whereas a residual increase of hospitalization risk was observed in patients on anti-CD20 therapies and a decrease in people on interferon

    SARS-CoV-2 serology after COVID-19 in multiple sclerosis: An international cohort study

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    DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

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    We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon
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