370 research outputs found

    Folding mechanisms steer the amyloid fibril formation propensity of highly homologous proteins

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    Significant advances in the understanding of the molecular determinants of fibrillogenesis can be expected from comparative studies of the aggregation propensities of proteins with highly homologous structures but different folding pathways. Here, we fully characterize, by means of stopped-flow, T-jump, CD and DSC experiments, the unfolding mechanisms of three highly homologous proteins, zinc binding Ros87 and Ml153-149 and zinc-lacking Ml452-151. The results indicate that the three proteins significantly differ in terms of stability and (un)folding mechanisms. Particularly, Ros87 and Ml153-149 appear to be much more stable to guanidine denaturation and are characterized by folding mechanisms including the presence of an intermediate. On the other hand, metal lacking Ml452-151 folds according to a classic two-state model. Successively, we have monitored the capabilities of Ros87, Ml452-151 and Ml153-149 to form amyloid fibrils under native conditions. Particularly, we show, by CD, fluorescence, DLS, TEM and SEM experiments, that after 168 hours, amyloid formation of Ros87 has started, while Ml153-149 has formed only amorphous aggregates and Ml452-151 is still monomeric in solution. This study shows how metal binding can influence protein folding pathways and thereby control conformational accessibility to aggregation-prone states, which in turn changes aggregation kinetics, shedding light on the role of metal ions in the development of protein deposition diseases

    Italian adaptation of the Edinburgh Social Cognition Test (ESCoT):A new tool for the assessment of theory of mind and social norm understanding

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    The relevance of social cognition assessment has been formally described in the Diagnostic and Statistical Manual of Mental Disorders-5. However, social cognition tools evaluating different socio-cognitive components for Italian-speaking populations are lacking. The Edinburgh Social Cognition Test (ESCoT) is a new social cognition measure that uses animations of everyday social interactions to assess (i) cognitive theory of mind, (ii) affective theory of mind, (iii) interpersonal social norm understanding, and (iv) intrapersonal social norm understanding. Previous studies have shown that the ESCoT is a sensitive measure of social cognition in healthy and clinical populations in the United Kingdom. This work aimed to adapt and validate the ESCoT in an Italian population of healthy adults. A translation-back-translation procedure was followed to create and refine the Italian version. Then, 94 healthy adults (47 females, mean age  35 ± 15.9) completed the ESCoT, a battery of conventional social cognition tests (Yoni; Reading the Mind in the Eyes Strange Stories, and Social Norm Questionnaire, SNQ) and measures of intelligence and executive functions. Reliability, convergent validity, and predictors of performance on the ESCoT were examined. Results demonstrated good reliability of the ESCoT and an association between the ESCoT scores and some traditional social cognition tests (Yoni cognitive subscale, SNQ). Hierarchical regression results showed that the ESCoT total score was associated with age. Also, the ESCoT subscore (intrapersonal social norm understanding) was associated with education. These findings support the ESCoT as a valid tool testing social norm understanding, a reliable measure of social cognition for an adult Italian population, and provides further evidence that the ESCoT is sensitive to age- and education-related changes in social cognition, and it is a task not affected by general cognitive functioning

    Modeling and Processing L-Band Ground Based Radar Data for Landslides Early Warning

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    L-band radars have been proposed as possible way for monitoring landslides. In this paper, we examine and solve the principal difficulties arising in modeling and processing radar data, evidencing differences with more usual SAR imaging. Numerical examples in support of the proposed processing procedure are finally provided

    Probing the Residual Structure in Avian Prion Hexarepeats by CD, NMR and MD Techniques

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    Many proteins perform essential biological functions by means of regions that lacking specific organized structure exist as an ensemble of interconverting transient conformers. The characterization of such regions, including the description of their structural propensities, number of conformations and relative populations can provide useful insights. Prion diseases result from the conversion of a normal glycoprotein into a misfolded pathogenic isoform. The structures of mammal and chicken prion proteins show a similar fold with a globular domain and a flexible N-terminal portion that contains different repeated regions: octarepeats (PHGGGWGQ) in mammals and hexarepeats (PHNPGY) in chickens. The higher number of prolines in the hexarepeat region suggests that this region may retain a significant amount of residual secondary structure. Here, we report the CD, NMR and MD characterization of a peptide (2-HexaPY) composed of two hexarepeats. We combine experimental NMR data and MD to investigate at atomic level its ensemble-averaged structural properties, demonstrating how each residue of both repeats has a different quantified PPII propensity that shows a periodicity along the sequence. This feature explains the absence of cooperativity to stabilize a PPII conformation. Nonetheless, such residual structure can play a role in nucleating local structural transitions as well as modulating intra-molecular or inter-molecular interactions

    Sex Influence on Fenestrated and Branched Endovascular Aortic Aneurysm Repair: Outcomes From a National Multicenter Registry

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    Introduction: Women are generally underrepresented in trials focusing on aortic aneurysm. Nevertheless, sex-related differences have recently emerged from several studies and registries. The aim of this research was to assess whether sex-related anatomical disparities existed in fenestrated and branched aortic repair candidates and whether these discrepancies could influence endovascular repair outcomes. Methods: Data from all consecutive patients treated during the 2008–2019 period within the Italian Multicenter fenestrated or branched endovascular aortic repair (F/BEVAR) Registry were included in the present study. Propensity matching was performed using a logistic regression model adjusted for demographic data and comorbidities to obtain comparable male and female samples. The selection model led to a final study population of 176 patients (88 women and 88 men) among the total initial cohort of 596. Study endpoints were technical and clinical success, overall survival, aneurysm-related death, and reintervention rates evaluated at 30 days and during follow-up. Results: Twenty-eight patients (15.9%) received urgent/emergent repair. In most of the cases (71.6%), women received treatment for extensive thoracoabdominal pathology (Crawford type I, II, or III aneurysm rather than type IV or juxta-pararenal) versus 46.6% of men (p=0.001). Female patients presented with more challenging iliac accesses with at least one side considered hostile in 27.3% of the cases (vs 13.6% in male patients, p=0.039). Finally, women had significantly smaller visceral vessels. Women had significantly worse operative outcomes, with an 86.2% technical success rate versus 96.6% in the male population (p=0.016). No differences were recorded in terms of 30-day reinterventions between men and women. The 5-year estimate of freedom from late reintervention, according to Kaplan-Meier analysis, was 85.6% in men versus 81.6% in women (p=ns). No aneurysm-related death was recorded during follow-up (median observational time, 23 months [interquartile range, 7–45 months]). Conclusion: Women presented a significantly higher incidence of thoracoabdominal aneurysms, smaller visceral vessels, and more complex iliofemoral accesses, resulting in a significantly lower technical success after F/BEVAR. Further studies assessing sex-related differences are needed to properly determine the impact on outcomes and stratify procedural risks. Clinical Impact: Women are generally underrepresented in trials focusing on aortic aneurysms. Aiming to assess whether sex may affect outcomes after a complex endovascular aortic repair, a propensity score selection was applied to a total population of 596 patients receiving F/BEVAR aortic repair with the Cook platform, matching each treated female patient with a corresponding male patient. Women presented more frequently a thoracoabdominal aneurysm extent, smaller visceral vessels, and complex iliofemoral accesses, resulting in significantly worse operative outcomes, with an 86.2% technical success versus 96.6% (p=0.016). No differences were recorded in terms of short-term and mid-term reinterventions. According to these results, careful and critical assessment should be posed in case of female patients receiving complex aortic repair, especially regarding preoperative anatomical evaluation and clinical selection with appropriate surgical risk stratification

    Penumbra indigo percutaneous aspiration thrombectomy system in the treatment of aortic endograft iliac limb occlusion: results from an Italian Multicentre Registry

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    Objective: This study aimed to evaluate the safety and effectiveness of the Penumbra Indigo percutaneous aspiration thrombectomy (PAT) system in the clinical presentation of iliac limb occlusion (ILO) after endovascular aortic repair (EVAR).Methods: A retrospective, observational, multicentre study conducted in eight Italian vascular centres. Consecutive patients presenting with ILO after EVAR were eligible. To assess vessel revascularisation, Thrombo-aspiration In Peripheral Ischaemia (TIPI) classification (score 0-3) was used at presentation (t1), after PAT (t2), and after adjunctive procedures (t3). Successful revascularisation was considered TIPI 2-3 (near complete or complete). Primary intra-operative outcomes were technical success (TS) of Indigo PAT and combined TS of PAT associated with adjunctive procedures when needed. Primary follow up outcomes were safety and effectiveness at one, six, and 12 months.Results: From September 2019 to December 2021, there were 48 ILO and 17 patients (35%) [median age 75 years, IQR 71, 83 years; male, 14 (82%); urgent, 8 (47%)] were treated and enrolled. The median time after primary EVAR was 24 months (IQR 0, 42 months). The median clot age from ILO diagnosis to PAT was three days (IQR 1, 12 days). Ten patients (59%) presented with limb threatening ischaemia. At t1, TIPI 0 and 1 was present in 13 (76%) and four (24%) cases, respectively. At t2, primary TS (TIPI 2-3) was achieved in 14 cases (82%) after Indigo PAT (p < .001). Fifteen patients (88%) required adjunctive procedures (14 re-linings, one surgical patch angioplasty). At t3, combined TS was achieved in 16 cases (94%). Intra-operative complication included one (6%) distal embolisation, treated successfully. The 30 day mortality was one case (6%) due to pneumonia. At one, six, and 12 months, clinical success was 100% without ILO recurrence. The median follow up was 23 months (IQR 11, 41 months): at 18 months, survival and freedom from re-intervention were 91 + 8% and 90 + 9%, respectively.Conclusion: This study reports for the first time the efficacy and safety of Penumbra Indigo PAT for ILO after EVAR, with promising technical and clinical success up to one year

    Cisplatin-based first-line treatment of elderly patients with advanced non-small-cell lung cancer: Joint analysis of MILES-3 and MILES-4 phase III trials

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    Purpose: To test the efficacy of adding cisplatin to first-line treatment for elderly patients with advanced non-small-cell lung cancer (NSCLC) within a combined analysis of two parallel phase III trials, MILES-3 and MILES-4. Patients and Methods: Patients with advanced NSCLC who were older than age 70 years with Eastern Cooperative Oncology Group performance status 0 to 1 were randomly assigned to gemcitabine or pemetrexed, without or with cisplatin. In each trial, 382 events were required to detect a hazard ratio (HR) of death of 0.75, with 80% power and two-tailed a of .05. Trials were closed prematurely because of slow accrual, but the joint database allowed us to analyze the efficacy of cisplatin on the basis of intention-to-treat and adjusted by trial, histotype, non-platinum companion drug, stage, performance status, sex, age, and size of the study center. Results: From March 2011 to August 2016, 531 patients (MILES-3, 299; MILES-4, 232) were assigned to gemcitabine or pemetrexed without (n = 268) or with cisplatin (n = 263). Median age was 75 years, 79% were male, and 70% had nonsquamous histology. At a median 2-year follow-up, 384 deaths and 448 progression-free survival events were recorded. Overall survival was not significantly prolonged with cisplatin (HR, 0.86; 95% CI, 0.70 to 1.05; P = .14) and global health status score of quality of life was not improved, whereas progression-free survival (HR, 0.76; 95% CI, 0.63 to 0.92; P = .005) and objective response rate (15.5% v 8.5%; P = .02) were significantly better. Significantly more severe hematologic toxicity, fatigue, and anorexia were found with cisplatin. Conclusion: The addition of cisplatin to single-agent chemotherapy does not significantly prolong overall survival, and it does not improve global health status score of quality of life in elderly patients with advanced NSCLC

    Does discussion lead to opinion change within Political Science students? A pedagogical exercise of deliberative democracy

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    While the model of deliberative democracy gives a crucial role to dialog, empirical evidence has not yet established if discussion helps to reach a better understanding of political issues and, above all, if individuals are prepared to change their views. It is still unclear when the deliberative model, and more specifically discussion, could be usefully employed as a teaching tool, to improve students’ knowledge. This article presents an exercise performed within the Department of Political and Social Sciences at the LUISS University of Rome. Students were asked to discuss in the classroom the issues related to the course, and to cast a vote on selected issues before and after deliberation. Although our sample is not representative, we have gathered evidence from the same population on a rather large number of issues. Students changed their view in 24.6% of cases, and they agreed that discussion increased their understanding, while those with strong ex-ante views resulted more reluctant to change their opinions because of discussion. The analysis also showed the presence of individuals that are more likely to be permeable to discussion while others that are more likely to be impermeable
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