34 research outputs found

    Difetti costruttivi negli edifici della provincia di Pisa: indagini e valutazioni critiche

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    L’interesse per l’argomento che si propone di sviluppare in questo lavoro di tesi nasce dall’evidente calo qualitativo che i nostri edifici hanno subito negli ultimi vent’anni e, di conseguenza, dalla necessità di individuare i difetti costruttivi più frequenti ed evidenziare in quale delle fasi del processo costruttivo il danno è stato originato. Questa tesi si presenta quindi come uno strumento informativo sulla reale qualità edilizia delle nostre costruzioni. Per raggiungere lo scopo proposto è stato necessario individuare lo strumento d’indagine che fosse in grado di fornire risultati il più possibile oggettivi ed effettivamente riscontrabili nella realtà. Nello sviluppo della ricerca è stato così utilizzato, come fonte informativa, l’archivio del Tribunale di Pisa, che ci ha consentito di analizzare i problemi emergenti nel tempo evidenziati dai fruitori del fabbricato. Tale scelta ha permesso di ottenere informazioni veritiere e riscontrabili, offrendo, altresì, una panoramica di tutto il territorio scelto in tempi altrimenti molto più lunghi e difficilmente inquadrabili nell’ambito di una tesi. La disamina di un consistente numero di Accertamenti Tecnici Preventivi, i cosiddetti ATP, ci ha così permesso di delineare i principali problemi e di capirne le cause. Tutti i casi esaminati sono stati quelli verificatisi dal 2000 fino ad oggi. Nel corso della ricerca sul territorio in esame abbiamo analizzato circa centoventi ATP in cui si sono riscontrati vizi e difetti costruttivi, sia negli edifici esistenti che di nuova o recente costruzione

    Tyrosine-phosphorylated caveolin is a physiological substrate of the low M(r) protein-tyrosine Phosphatase

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    Low M(r) phosphotyrosine-protein phosphatase is involved in the regulation of several tyrosine kinase growth factor receptors. The best characterized action of this enzyme is on the signaling pathways activated by platelet-derived growth factor, where it plays multiple roles. In this study we identify tyrosine-phosphorylated caveolin as a new potential substrate for low M(r) phosphotyrosine-protein phosphatase. Caveolin is tyrosine-phosphorylated in vivo by Src kinases, recruits into caveolae, and hence regulates the activities of several proteins involved in cellular signaling cascades. Our results demonstrate that caveolin and low M(r) phosphotyrosine-protein phosphatase coimmunoprecipitate from cell lysates, and that a fraction of the enzyme localizes in caveolae. Furthermore, in a cell line sensitive to insulin, the overexpression of the C12S dominant negative mutant of low M(r) phosphotyrosine-protein phosphatase (a form lacking activity but able to bind substrates) causes the enhancement of tyrosine-phosphorylated caveolin. Insulin stimulation of these cells induces a strong increase of caveolin phosphorylation. The localization of low M(r) phosphotyrosine-protein phosphatase in caveolae, the in vivo interaction between this enzyme and caveolin, and the capacity of this enzyme to rapidly dephosphorylate phosphocaveolin, all indicate that tyrosine-phosphorylated caveolin is a relevant substrate for this phosphatase

    Adenosine receptor expression in an experimental animal model of myocardial infarction with preserved left ventricular ejection fraction.

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    Adenosine, a purine nucleoside and a "retaliatory metabolite" in ischemia, is ubiquitous in the body and increases 100-fold during ischemia. Its biological actions are mediated by four adenosine receptors (ARs): A(1), A(2A), A(2B) and A(3). The aim of this study was to determine possible myocardial alterations in AR expression in an experimental animal model of myocardial infarction (MI) with a preserved left ventricular (LV) ejection fraction. LV tissue was collected from sexually mature male farm pigs with MI (n = 6) induced by permanent surgical ligation of the left anterior descending coronary artery and from five healthy pigs (C). mRNA expression of A(1)R, A(2A)R, A(2B)R, A(3)R and TNF-? was determined by real-time PCR in tissue collected from border (BZ) and remote zones (RZ) of the infarcted area and from LV of C. BZ, RZ and samples of C were stained immunohistochemically to investigate A(3)R immunoreaction. After 4 weeks a different regulation of ARs was observed. A(1)R mRNA expression was significantly lower in the infarct regions than in controls (C = 0.75 ? 0.2, BZ = 0.05 ? 0.2, RZ = 0.07 ? 0.02 p = 0.0025, p = 0.0016, C vs. BZ and RZ, respectively). Conversely A(3)R was higher in infarct areas (C = 0.94 ? 0.2, BZ = 2.85 ? 0.5, RZ = 3.48 ? 1.0, p = 0.048 C vs. RZ). No significant differences were observed for A(2A)R (C = 1.58 ? 0.6, BZ = 0.42 ? 0.1, RZ = 1.37 ? 0.6) and A(2B)R (C = 1.66 ? 0.2, BZ = 1.54 ? 0.5, RZ = 1.25 ? 0.4). A(3)R expression was confirmed by immunohistochemical analysis and was principally localized in cardiomyocytes. TNF-? mRNA results were: C 0.41 ? 0.25; BZ 1.60 ? 0.19; RZ 0.17 ? 0.04. The balance between A(1)R and A(3)R as well as between A(2A)R and A(2B)R was consistent with adaptative retaliatory anti-ischemic adenosinergic changes in the infarcted heart with preserved LV function

    The effects of CA IX catalysis products within tumor microenvironment

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    Solid tumors are composed of both cancer cells and various types of accessory cells, mainly fibroblasts, that collectively compose the so called tumor-microenvironment. Cancer-associated fibroblasts have been described to actively participate in cancer progression by establishing a cytokine-mediated as well as metabolic crosstalk with cancer cells. In the present paper we show that activated human fibroblasts are able to boost tumor cells proliferation and that this effect is greatly dependent on stromal carbonic anhydrase IX (CA IX) activity. In fact fibroblasts show a strong upregulation of CA IX expression upon activation by cancer cells, while CA IX products, protons and bicarbonate, exert differential effects on cancer cells proliferation. While acidification of extracellular pH, a typical condition of rapidly growing solid tumors, is detrimental for tumor cells proliferation, bicarbonate, through its organication, supplies cancer cells with intermediates useful to sustain their high proliferation rate. Here we propose a new kind of fibroblasts/tumor cells crosstalk within tumor microenvironment, mediated by stromal CA IX products, aimed to favor cancer cells growth, opening new perspectives on CA IX role in tumor microenvironment

    High concentration of C-type natriuretic peptide promotes VEGF-dependent vasculogenesis in the remodeled region of infarcted swine heart with preserved left ventricular ejection fraction.

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    Abstract BACKGROUND: Vasculogenesis is a hallmark of myocardial restoration. Post-ischemic late remodeling is associated with pathology and function worsening. At the same time, neo-vasculogenesis helps function improving and requires the release of vascular endothelial growth factor type A (VEGF-A). The vasculogenic role of C-type natriuretic peptide (CNP), a cardiac paracrine hormone, is unknown in infarcted hearts with preserved left ventricular (LV) ejection fraction (EF). We explored whether myocardial VEGF-dependent vasculogenesis is affected by CNP. METHODS AND RESULTS: To this end, infarcted swine hearts were investigated by magnetic resonance imaging (MRI), histological and molecular assays. At the fourth week, MRI showed that transmural myocardial infarction (MI) affected approximately 13% of the LV wall mass without impairing global function (LVEF>50%, n=9). Increased fibrosis, metalloproteases and capillary density were localized to the infarct border zone (BZ), and were associated with increased expression of CNP (p=0.03 vs. remote zone (RZ)), VEGF-A (p<0.001 vs. RZ), BNP, a marker of myocardial dysfunction (p<0.01 vs. RZ) and the endothelial marker, factor VIII-related antigen (p<0.01 vs. RZ). In vitro, CNP 1000 nM promoted VEGF-dependent vasculogenesis without affecting the cell growth and survival, although CNP 100 nM or a high concentration of VEGF-A halted vascular growth. CONCLUSIONS: CNP expression is locally increased in infarct remodeled myocardium in the presence of dense capillary network. The vasculogenic response requires the co-exposure to high concentration of CNP and VEGF-A. Our data will be helpful to develop combined myocardial delivery of CNP and VEGF-A genes in order to reverse the remodeling process

    Severe exacerbations of chronic obstructive pulmonary disease: management with noninvasive ventilation on a general medicine ward

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    Introduction: Recent evidence suggests that, with a well-trained staff, severe exacerbations of chronic obstructive pulmonary disease (COPD) with moderate respiratory acidosis (pH > 7.3) can be successfully treated with noninvasive mechanical ventilation (NIMV) on a general respiratory care ward. We conducted an open prospective study to evaluate the efficacy of this approach on a general medicine ward. Material and methods: This study population consisted in 27 patients admitted to a general medicine ward (median nurse:patient ratio 1:12) December 1, 2004 May 31, 2006 for acute COPD exacerbation with hypercapnic respiratory failure and acidosis (arterial pH 45 mmHg). All received assist-mode NIMV (average 12 h / day) via oronasal masks (inspiratory pressure 10-25 cm H2O, expiratory pressure 4-6 cm H2O) to maintain O2 saturation at 90-95%. Treatment was supervised by an experienced pulmonologist, who had also provided specific training in NIMV for medical and nursing staffs (90-day course followed by periodic refresher sessions). Arterial blood pressure, O2 saturation, and respiratory rate were continuously monitored during NIMV. Based on baseline arterial pH, the COPD was classified as moderate (7.25-7.34) or severe (< 7.25). Results: In patients with moderate and severe COPD, significant improvements were seen in arterial pH after 2 (p < 0.05) and 24 h (p< 0.05) of NIMV and in the PaC02 after 24 hours (p < 0.05). Four (15%) of the 27 patients died during the study hospitalization (in-hospital mortality 15%), in 2 cases due to NIMV failure. For the other 23, mean long-term survival was 14.5 months (95% CI 10.2 to 18.8), and no significant differences were found between the moderate and severe groups. Over half (61%) the patients were alive 1 year after admission. Conclusions: NIMV can be a cost-effective option for management of moderate or severe COPD on a general medicine ward. Its proper use requires: close monitoring of ventilated subjects, optimum staff:patient ratio, well-trained staff dedicated to NIMV, and supervision by a pulmonologist with experience in NIMV. The treatment was effective at improving arterial blood gases in both groups of COPD patients. The severity of the COPD did not significantly affect length of hospital stay, in-hospital mortality, or long-term survival

    SHMT2-mediated mitochondrial serine metabolism drives 5-FU resistance by fueling nucleotide biosynthesis

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    5-Fluorouracil (5-FU) is a key component of chemotherapy for colorectal cancer (CRC). 5-FU efficacy is established by intracellular levels of folate cofactors and DNA damage repair strategies. However, drug resistance still represents a major challenge. Here, we report that alterations in serine metabolism affect 5-FU sensitivity in in vitro and in vivo CRC models. In particular, 5-FU-resistant CRC cells display a strong serine dependency achieved either by upregulating endogenous serine synthesis or increasing exogenous serine uptake. Importantly, regardless of the serine feeder strategy, serine hydroxymethyltransferase-2 (SHMT2)-driven compartmentalization of one-carbon metabolism inside the mitochondria represents a specific adaptation of resistant cells to support purine biosynthesis and potentiate DNA damage response. Interfering with serine availability or affecting its mitochondrial metabolism revert 5-FU resistance. These data disclose a relevant mechanism of mitochondrial serine use supporting 5-FU resistance in CRC and provide perspectives for therapeutic approaches

    Il monastero di Sant'Antonio in Polesine a Ferrara e l'iconografia della passione di Cristo

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    Targeting of tumor cells by custom antigen transfer: a novel approach for immunotherapy of cancer

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    In the early stages of carcinogenesis, the transformed cells become "invisible" to the immune system. From this moment on, the evolution of the tumor depends essentially on the genotype of the primitive cancer cells and their subsequent genetic drift. The role of the immune system in blocking tumor progression from the earliest stages is largely underestimated because by the time tumors are clinically detectable, the immune system has already completely failed its task. Therefore, a clinical treatment capable of restoring the natural anti-tumor role of the immune system could prove to be the "ultimate weapon" against cancer. Herein, we propose a novel therapeutic approach for the treatment of solid cancer that exploits the capability of activated monocytes to transfer major histocompatibility complex I (MHC-I) molecules bound to antigenic peptides to cancer cells using microvesicles as cargo, making tumor cells target of a "natural" CD8+ T lymphocyte cytotoxic response
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