INCREASED SURVIVAL OF CLL B CELLS IN THE PRESENCE OF MARROW MESENCHYMAL STROMAL CELLS: A NOVEL MODEL TO DEFINE NEW TARGETS FOR THERAPY

Chronic Lymphocytic Leukemia (CLL) is the most common leukemia in the Western World, accounting for about 30% of adult leukemia, and it is characterized by the clonal expansion and accumulation of mature CD19+/CD5+/CD23+ B lymphocytes in the peripheral blood, bone marrow and secondary lymphoid organs. Despite their apparent longevity in patients, in vitro CLL leukemic B cells rapidly undergo spontaneous apoptosis. The selective survival advantage is due both to intrinsic defects on apoptosis mechanism and to signals delivered by accessory cells at the active site of the disease. Previous studies demonstrated that mesenchymal stromal cells (MSCs), derived from bone marrow, and CD68+ nurse-like cells, derived from peripheral blood, are involved in CLL clone longevity and migration, suggesting a crucial role of MSCs on favouring disease progression. Therefore, in this thesis we evaluated the effect of MSCs, the main stromal population in the bone marrow of CLL patients, on the survival of leukemic B cells and their role in drug resistance. MSCs were isolated from the bone marrow of 46 CLL patients; their immunophenotypic characterization was based on the expression of CD105, CD73 and CD90 and the negativity of CD14, CD34, CD45 and CD31. Co-culturing MSCs and CLL B cells, we confirmed that MSCs are able to support malignant B cell survival, providing an in vitro culture system that closely approximates CLL microenvironment in vivo. We observed that different leukemic clones demonstrated a large variety in the pro-survival effect. Evaluating the cleavage pattern of PARP, we revealed two subsets of CLL clones with different sensitivity to MSCs pro-survival signals. Our results indicate that both cell-cell contact and soluble molecules are actors in the relationship between malignant B cells and the MSCs, promoting CLL B cell survival and migration. Later, we evaluated the role of the MSCs on CLL B cells during the most common cytotoxic therapy used in clinical practice. Our data demonstrate that MSCs are able to protect leukemic B cells from apoptosis during Fludarabine and Cyclophosphamide treatment, both in vitro and in vivo. We tested MSCs protective role also during CLL B cells treatment with Ibrutinib, a novel inhibitor of Btk involved in the BCR signaling pathway, and we found that the treatment counteracts the MSC pro-survival effect. To better understand the effect of Ibrutinib on the cross-talk between CLL B cells and MSCs, we evaluated its role on leukemic B cell migration, also analyzing the expression levels of CCR7 and CXCR4, two chemokine receptors that are central in the homing of the neoplastic clone. We demonstrated that malignant B cell migration is not significantly affected by the Btk inhibitor; since cell-cell contact with MSC is crucial for CLL B cell survival, we analyzed the adhesion of leukemic B cells to MSCs after treatment with Ibrutinib. We found a significant reduction in leukemic B cells and MSCs interactions mediated by the CD49d integrin. In this thesis, we demonstrate that MSCs enhance the survival of leukemic B cells through the release of soluble factors and cell-cell direct contact and that each CLL clone reveals a peculiar response to the anti-apoptotic signals delivered by MSCs. These observations could be relevant to identify patients more responsive to druggable targets on marrow microenvironment and also to find putative new strategies for CLL therapy. A better understanding on the complexity of the cross-talk between CLL cells and their microenvironment during CLL therapy could also help to define mechanisms of drug resistance and treatment failure, as well to plan randomized clinical trials comparing new compounds and their combinations with standard chemo-immunotherapy

A simple procedure to calibrate soil parameters for slope stability modelling: the Langhe (1994) case study

Shallow landslides triggered by rainfall represent common geotechnical hazards in Italy. In this context, the hundreds of landslides which occurred in the Piedmont Langhe area in November 1994, still identified among the most extensive areal event in the last 30 years in Italy, are investigated. Exploiting data from the surveys of Campus et al. (1998), here we calibrate simple soil water and mechanical properties (i.e., the saturated permeability and cohesion values) to overcome the large uncertainty affecting the determination of parameters to be used as inputs for physically based soil slip models. This work aims to contribute to the development of reliable soil data inventory that may be of direct interest in slope stability modelling, following Vannocci et al. (2020). The analysis was conducted on a small number of cases selected from a sample of 238 observed landslides, to which geometries and geotechnical features were attributed from a regional database. The calibration was performed using a simple hydrological model, i.e. that of Rosso et al. (2006), since it allows a reasonable check on the sensitivity of soil parameter values to the instability conditions. For saturated conductivity, a variation range was obtained, whose upper limit referred to the so-called bucket model. Assuming that part of the rainfall contributes to surface runoff, a lower permeability value was derived using the proportional flow method ψ, consistently with the real dynamics of the processes. Soil cohesion was calibrated by mechanical analysis based on the infinite slope theory, by targeting the Safety Factor SF to assume the value 0.99. When comparing locally calibrated parameters and the reference ones found in the database some differences arise; in particular, in several cases, based on calibrated values, SFs quite lower than 1 were derived. It must be pointed out that the calibration procedure allowed us to characterize shallow soils, made up of remolded and often vegetated soil, while the regional dataset provide information on undisturbed soil samples, typically collected at depths greater than those of interest. The possibility of getting reliable soil parameters to be used in physically based modelling of shallow landslides is a complex task. Here we use a calibration method to obtain meaningful saturated hydraulic conductivity and cohesion values, compatible with the observed instabilities. The implications of the differences found between the calibrated parameters and those published in the regional dataset will lay the foundations for subsequent investigations, as this analysis will be part of the research framework of the RETURN Extended Partnership Project

A Novel Approach to Assess the Influence of Rockfall Source Areas: The Case Study of Bardonecchia (Italy)

In this research article, we propose a practical methodology for evaluating the affecting potential of detachment areas in rockfalls. Our innovative approach combines an assessment of the visibility of rockfall source areas, with reference to specific rockfall scenarios and elements at risk, considering the rockfall Susceptibility Index to Failure (SIF) of these areas. The result is the characterization of source areas through a rockfall Source Affecting Index (SAI), which considers both the morphology of the slope and the geostructural conditions of the rock walls. This information can be very useful since it aids in optimizing more in-depth analyses, as well as the placement of monitoring instruments or stabilization systems. The proposed methodology has been implemented in the open-source software QGIS through the development of an easy-to-use plugin named Ranking of the Affecting Potential of Detachment Areas in Rockfalls, or “RADAR”. RADAR is designed to be used in conjunction with QPROTO, a well-known QGIS plugin for preliminary rockfall susceptibility/hazard analyses based on a visibility analysis and a simplified mechanical method. To demonstrate the effectiveness of the proposed approach, an application to a case study located in the Western Alps (Bardonecchia, Italy) is presented and discussed in the paper

What's the best treatment setting for stable PE patients?

Review of: Roy PM, Corsi DJ, Carrier M, et al. Net clinical benefit of hospitalization versus outpatient management of patients with acute pulmonary embolism. J Thromb Haemost. 2017;15:685-694.3 pagesWhat's the best treatment setting for stable PE patients? The answer seems to be the outpatient setting. Here's why. PRACTICE CHANGER: Manage patients with acute pulmonary embolism (PE) who are hemodynamically stable in the outpatient setting to decrease adverse events--regardless of their initial risk category. STRENGTH OF RECOMMENDATION: B: Based upon a good-quality retrospective cohort propensity score analysis.Authors: Monica Schaffer, MD; Gregory Castelli, PharmD, BCPS, BC-ADM UPMC St. Margaret, Pittsburgh, Pa

A Quick QGIS-Based Procedure to Preliminarily Define Time-Independent Rockfall Risk: The Case Study of Sorba Valley, Italy

Rockfalls are widespread, rapid, and high-energy landslide phenomena that could poten- tially affect large portions of populated lands. The preliminary identification of the most rockfall- prone zones is a challenging task, especially in times of extreme and unpredictable climate change. Even slight environmental modifications can produce significant consequences in terms of exposure, hazard, and risk. Therefore, a timely risk assessment is paramount for territorial administrators to plan and prioritize adequate countermeasures. Risk assessment is crucial to guaranteeing the safety of human lives, the integrity of structures and infrastructures, the preservation of historic and environmental heritage, and the safeguard of economic activities. Hence, new and rapid evaluation methods for rockfall hazard, vulnerability, and risk are needed to identify the most critical areas where more indepth analyses aimed at the design of protective works should be carried out. This study proposes a quick, innovative, and completely GIS-based procedure to preliminarily assess rockfall time-independent hazard and risk in large areas. Propagation analysis is performed by integrating powerful QGIS plugin QPROTO, which can estimate rockfall energy within the invasion area in a simplified way, with the slope units polygons of the Italian territory for the definition of the input parameters. The quantification of risk was obtained by the application of the multidisciplinary IMIRILAND methodology, again within a free and open QGIS environment. Lastly, to test the capabilities of the method, the procedure was applied to a case study of the Sorba Valley (Piemonte, Italy), a tourist region in the northwestern Italian Alps. The findings offer an important contribution to the field of land-planning activities and risk-management strategies

Fighting tertiary mutations in EGFR-driven lung-cancers: Current advances and future perspectives in medicinal chemistry

Third-generation inhibitors of the epidermal growth factor receptor (EGFR), best exemplified by osimertinib, have been developed to selectively target variants of EGFR bearing activating mutations and the mutation of gatekeeper T790 in patients with EGFR-mutated forms of Non-Small Cell Lung Cancer (NSCLC). While the application of third-generation inhibitors has represented an effective first- and second-line treatment, the efficacy of this class of inhibitors has been hampered by the novel, tertiary mutation C797S, which may occur after the treatment with osimertinib. More recently, other point mutations, including L718Q, G796D, G724S, L792 and G719, have emerged as mutations mediating resistance to third-generation inhibitors. The challenge of overcoming newly developed and recurrent resistances mediated by EGFR-mutations is thus driving the search of alternative strategies in the design of new therapeutic agents able to block EGFR-driven tumor growth. In this manuscript we review the recently emerged EGFR-dependent mechanisms of resistance to third-generation inhibitors, and the achievements lately obtained in the development of next-generation EGFR inhibitors

Cross-talk between chronic lymphocytic leukemia (CLL) tumor B cells and mesenchymal stromal cells (MSCs): implications for neoplastic cell survival

Leukemic cells from Chronic Lymphocytic Leukemia (CLL) patients interact with stromal cells of the surrounding microenvironment. Mesenchymal Stromal Cells (MSCs) represent the main population in CLL marrow stroma, which may play a key role for disease support and progression. In this study we evaluated whether MSCs influence in vitro CLL cell survival. MSCs were isolated from the bone marrow of 46 CLL patients and were characterized by flow cytometry analysis. Following co-culture of MSCs and leukemic B cells, we demonstrated that MSCs were able to improve leukemic B cell viability, this latter being differently dependent from the signals coming from MSCs. In addition, we found that the co-culture of MSCs with leukemic B cells induced an increased production of IL-8, CCL4, CCL11, and CXCL10 chemokines.As far as drug resistance is concerned, MSCs counteract the cytotoxic effect of Fludarabine/Cyclophosphamide administration in vivo, whereas they do not protect CLL cells from the apoptosis induced by the kinase inhibitors Bafetinib and Ibrutinib. The evidence that leukemic clones are conditioned by environmental stimuli suggest new putative targets for therapy in CLL patients

Association between a genetic variant of type-1 cannabinoid receptor and inflammatory neurodegeneration in multiple sclerosis

Genetic ablation of type-1 cannabinoid receptors (CB1Rs) exacerbates the neurodegenerative damage of experimental autoimmune encephalomyelitis, the rodent model of multiple sclerosis (MS). To address the role on CB1Rs in the pathophysiology of human MS, we first investigated the impact of AAT trinucleotide short tandem repeat polymorphism of CNR1 gene on CB1R cell expression, and secondly on the inflammatory neurodegeneration process responsible for irreversible disability in MS patients. We found that MS patients with long AAT repeats within the CNR1 gene (≥12 in both alleles) had more pronounced neuronal degeneration in response to inflammatory white matter damage both in the optic nerve and in the cortex. Optical Coherence Tomography (OCT), in fact, showed more severe alterations of the retinal nerve fiber layer (RNFL) thickness and of the macular volume (MV) after an episode of optic neuritis in MS patients carrying the long AAT genotype of CNR1. MS patients with long AAT repeats also had magnetic resonance imaging (MRI) evidence of increased gray matter damage in response to inflammatory lesions of the white matter, especially in areas with a major role in cognition. In parallel, visual abilities evaluated at the low contrast acuity test, and cognitive performances were negatively influenced by the long AAT CNR1 genotype in our sample of MS patients. Our results demonstrate the biological relevance of the (AAT)n CNR1 repeats in the inflammatory neurodegenerative damage of MS

L’evoluzione degli atteggiamenti verso la matematica e il suo insegnamento degli insegnanti di scuola elementare in formazione iniziale

Il percorso formativo come docenti di scuola elementare in didattica della matematica può essere fortemente influenzato da fattori di natura affettiva, che, a loro volta, risultano spesso legati ad esperienze scolastiche negative vissute con la matematica. Il progetto di ricerca-azione qui descritto ha approfondito proprio questo fenomeno, focalizzandosi sui futuri docenti di scuola elementare del Canton Ticino, con un duplice obiettivo: da un lato, progettare e implementare efficaci pratiche formative per lo svilup- po di atteggiamenti positivi verso la matematica e il suo insegnamento; dall’altro, studiare l’evoluzione di tali atteggiamenti nell’arco dei primi due anni della formazione. Sono stati sviluppati specifici interventi didattici e strumenti di osservazione che hanno permesso di rilevare e monitorare gli atteggiamenti degli studenti e di analizzare quali dimensioni – disposizione emozionale, senso di autoefficacia, visione della disciplina (Di Martino & Zan, 2011) – sono state più o meno influenti sul cambiamento di atteggiamento, e su quali componenti quindi la formazione può cercare di intervenire in modo più incisivo ed efficace