Dissertazioni sopra la storia ecclesiastica lucchese,

Vol. [2] by Domenico Barsocchini.

Biomechanics of the rostrum in crocodilians: A comparative analysis using finite-element modeling

This article reports the use of simple beam and finite-element models to investigate the relationship between rostral shape and biomechanical performance in living crocodilians under a range of loading conditions. Load cases corresponded to simple biting, lateral head shaking, and twist feeding behaviors. The six specimens were chosen to reflect, as far as possible, the full range of rostral shape in living crocodilians: a juvenile Caiman crocodilus, subadult Alligator mississippiensis and Crocodylus johnstoni, and adult Caiman crocodilus, Melanosuchus niger, and Paleosuchus palpebrosus. The simple beam models were generated using morphometric landmarks from each specimen. Three of the finite-element models, the A. mississippiensis, juvenile Caiman crocodilus, and the Crocodylus johnstoni, were based on CT scan data from respective specimens, but these data were not available for the other models and so these-the adult Caiman crocodilus, M. niger, and P. palpebrosus-were generated by morphing the juvenile Caiman crocodilus mesh with reference to three-dimensional linear distance measured from specimens. Comparison of the mechanical performance of the six finite-element models essentially matched results of the simple beam models: relatively tall skulls performed best under vertical loading and tall and wide skulls performed best under torsional loading. The widely held assumption that the platyrostral (dorsoventrally flattened) crocodilian skull is optimized for torsional loading was not supported by either simple beam theory models or finite-element modeling. Rather than being purely optimized against loads encountered while subduing and processing food, the shape of the crocodilian rostrum may be significantly affected by the hydrodynamic constraints of catching agile aquatic prey. This observation has important implications for our understanding of biomechanics in crocodilians and other aquatic reptiles.

Design Strategies and Modelling of Low-Power Sigma-Delta Analog-to-Digital Converters

Oggi, i dispositivi portatili sono diventati la forza trainante del mercato consumer e nuove sfide stanno emergendo per aumentarne le prestazioni, pur mantenendo un ragionevole tempo di vita della batteria. Il dominio digitale è la miglior soluzione per realizzare funzioni di elaborazione del segnale, grazie alla scalabilità della tecnologia CMOS, che spinge verso l'integrazione a livello sub-micrometrico. Infatti, la riduzione della tensione di alimentazione introduce limitazioni severe per raggiungere un range dinamico accettabile nel dominio analogico. Minori costi, minore consumo di potenza, maggiore resa e una maggiore riconfigurabilità sono i principali vantaggi dell'elaborazione dei segnali nel dominio digitale. Da più di un decennio, diverse funzioni puramente analogiche sono state spostate nel dominio digitale. Ciò significa che i convertitori analogico-digitali (ADC) stanno diventando i componenti chiave in molti sistemi elettronici. Essi sono, infatti, il ponte tra il mondo digitale e analogico e, di conseguenza, la loro efficienza e la precisione spesso determinano le prestazioni globali del sistema. I convertitori Sigma-Delta sono il blocco chiave come interfaccia in circuiti a segnale-misto ad elevata risoluzione e basso consumo di potenza. I tools di modellazione e simulazione sono strumenti efficaci ed essenziali nel flusso di progettazione. Sebbene le simulazioni a livello transistor danno risultati più precisi ed accurati, questo metodo è estremamente lungo a causa della natura a sovracampionamento di questo tipo di convertitore. Per questo motivo i modelli comportamentali di alto livello del modulatore sono essenziali per il progettista per realizzare simulazioni veloci che consentono di identificare le specifiche necessarie al convertitore per ottenere le prestazioni richieste. Obiettivo di questa tesi è la modellazione del comportamento del modulatore Sigma-Delta, tenendo conto di diverse non idealità come le dinamiche dell'integratore e il suo rumore termico. Risultati di simulazioni a livello transistor e dati sperimentali dimostrano che il modello proposto è preciso ed accurato rispetto alle simulazioni comportamentali.

Mechanisms of Mycoplasma-induced inflammation and cellular transformation

There is a growing interest in “medical gasses” for their antibacterial and anti-inflammatory properties. Hydrogen sulfide (H2S), a member of the family of gasotransmitters, is in fact increasingly being recognized as an important signaling molecule, but its precise role in the regulation of the inflammatory response is still not clear. For this reason, the aim of the first part of this thesis was to investigate the effects of H2S on the expression of pro-inflammatory cytokines, such as MCP-1, by using an in vitro model composed by both primary monocytes-derived macrophages cultures and the human monocytic cell line U937 infected with Mycoplasma fermentans, a well-known pro-inflammatory agent. In our experiments, we observed a marked increase in the production of pro-inflammatory cytokines in infected cells. In particular, MCP-1 was induced both at the RNA and at the protein level. To test the effects of H2S on infected cells, we treated the cells with two different H2S donors (NaHS and GYY4137), showing that both H2S treatments had anti-inflammatory effects in Mycoplasma-infected cells: the levels of MCP-1, both mRNA expression and protein production, were reduced. Our subsequent studies aimed at understanding the molecular mechanisms responsible for these effects, focused on two specific molecular pathways, both involved in inflammation: the NF-κB and the Nrf2 pathway. After treatment with pharmacological inhibitors, we demonstrated that Mycoplasma fermentans induces MCP-1 expression through the TLR-NF-κB pathway with the nuclear translocation of its subunits, while treatment with H2S completely blocked the nuclear translocation of NF-κB heterodimer p65/p50. Then, once infected cells were treated with H2S donors, we observed an increased protective effect of Nrf2 and also a decrease in ROS production. These results highlight the importance of H2S in reducing the inflammatory process caused by Mycoplasma fermentans. To this regard, it should be noted that several projects are currently ongoing to develop H2S-releasing compounds as candidate drugs capable of alleviating cell deterioration and to reduce the rate of decline in organ function. In the second part of this study, we investigated the role of Mycoplasma infection in cellular transformation. Infectious agents are involved in the etiology of many different cancers and a number of studies are still investigating the role of microbiota in tumor development. Mycoplasma has been associated with some human cancers, such as prostate cancer and non-Hodgkin’s lymphoma in HIV-seropositive people, and its potential causative role and molecular mechanisms involved are being actively investigated. To this regard, in vitro studies demonstrated that, upon infection, Mycoplasma suppresses the transcriptional activity of p53, key protein in the cancer suppression. As a consequence, infected cells were less susceptible to apoptosis and proliferated more than the uninfected cells. The mechanism(s) responsible for the Mycoplasma-induced inhibitory effect on p53 were not determined. Aim of the second part of this thesis was to better understand the tumorigenic role of the microorganism, by investigating more in details the effect(s) of Mycoplasma on p53 activity in an adenocarcinoma HCT116 cell line. Treatment of Mycoplasma-infected cells with 5FU or with Nutlin, two molecules that induce p53 activity, resulted in cellular proliferation comparable to untreated controls. These results suggested that Mycoplasma infection inhibited p53 activity. Immunoprecipitation of p53 with specific antibodies, and subsequent Gas Chromatography and Mass Spectroscopy (GC-MS) assays, allowed us to identify several Mycoplasma-specific proteins interacting with p53, such as DnaK, a prokaryotic heat shock protein and stress inducible chaperones. In cells transfected with DnaK we observed i) reduced p53 protein levels; ii) reduced activity and expression of p21, Bax and PUMA, iii) a marked increase in cells leaving G1 phase. Taken together, these data show an interaction between the human p53 and the Mycoplasma protein DnaK, with the consequent decreased p53 activity and decreased capability to respond to DNA damage and prevent cell proliferation. Our data indicate that Mycoplasma could be involved in cancer formation and the mechanism(s) has the potential to be a target for cancer diagnosis and treatment(s).

La geochimica degli isotopi stabili applicata a reperti scheletrici fossili per ricostruzioni paleoambientali (sito archeologico di Arslantepe –Turchia).

Il sito archeologico di Arslantepe (provincia di Malatya, Turchia) rappresenta un caso di studio di potenziale interesse per l’interazione tra i mutamenti climatici e la storia della civiltà. Il sito, occupato quasi ininterrottamente per un periodo di tempo relativamente lungo (6250-2700 BP), ha fornito una grande quantità di reperti ossei, distribuiti lungo una stratigrafia archeologica relativamente dettagliata e supportata da datazioni al radiocarbonio. Tali reperti, indagati con le tecniche della geochimica degli isotopi stabili, possono costituire degli efficaci proxy paleoclimatici. In questo lavoro è stata studiata la composizione isotopica di 507 campioni di resti ossei umani e animali (prevalentemente pecore, capre, buoi). I rapporti isotopici studiati sono relativi a ossigeno (δ18Ocarb, δ18Oph), carbonio (δ13Ccarb, δ13Ccoll) e azoto (δ15N), misurati nella frazione minerale e organica dell’osso; la variabilità nel tempo di questi parametri, principalmente legati alla paleonutrizione, può essere correlata, direttamente o indirettamente, a cambiamenti dei parametri ambientali quali temperatura e umidità atmosferiche. I risultati indicano che la dieta degli animali selvatici e domestici di Arslantepe era quasi esclusivamente a base di piante a ciclo fotosintetico C3, generalmente tipiche di climi umidi o temperati. La presenza di piante C4, più tipiche di condizioni aride, sembrerebbe essere riconoscibile solamente nella dieta del bue (Bos taurus). La dieta umana era esclusivamente terrestre a base di cereali e carne di caprini con una percentuale esigua o del tutto assente di carne di maiale e bue. Dal punto di vista paleoclimatico il principale risultato del lavoro consiste nel riconoscimento della preservazione di un segnale paleoclimatico a lungo termine (δ18OW, composizione isotopica dell’ossigeno dell’acqua ingerita), che identifica un massimo relativo di umidità attorno al 5000 BP e che si correla, per andamento e ampiezza della variazione a record paleoclimatici di sedimenti lacustri collocati in regioni adiacenti all’area di studio. Sulla base del confronto dei tre segnali isotopici sono state inoltre riconosciute due anomalie climatiche siccitose a breve termine, apparentemente riferibili a due episodi di aridità a scala regionale documentati in letteratura.

Spectroscopic analysis of terrestrial analogues for the interpretation of surface composition of rocky bodies in the solar system. Effects of mineral mixing and particle size. Applications to moon, mars and implications for mercury.

Among the Solar System’s bodies, Moon, Mercury and Mars are at present, or have been in the recent years, object of space missions aimed, among other topics, also at improving our knowledge about surface composition. Between the techniques to detect planet’s mineralogical composition, both from remote and close range platforms, visible and near-infrared reflectance (VNIR) spectroscopy is a powerful tool, because crystal field absorption bands are related to particular transitional metals in well-defined crystal structures, e.g., Fe2+ in M1 and M2 sites of olivine or pyroxene (Burns, 1993). Thanks to the improvements in the spectrometers onboard the recent missions, a more detailed interpretation of the planetary surfaces can now be delineated. However, quantitative interpretation of planetary surface mineralogy could not always be a simple task. In fact, several factors such as the mineral chemistry, the presence of different minerals that absorb in a narrow spectral range, the regolith with a variable particle size range, the space weathering, the atmosphere composition etc., act in unpredictable ways on the reflectance spectra on a planetary surface (Serventi et al., 2014). One method for the interpretation of reflectance spectra of unknown materials involves the study of a number of spectra acquired in the laboratory under different conditions, such as different mineral abundances or different particle sizes, in order to derive empirical trends. This is the methodology that has been followed in this PhD thesis: the single factors previously listed have been analyzed, creating, in the laboratory, a set of terrestrial analogues with well-defined composition and size. The aim of this work is to provide new tools and criteria to improve the knowledge of the composition of planetary surfaces. In particular, mixtures composed with different content and chemistry of plagioclase and mafic minerals have been spectroscopically analyzed at different particle sizes and with different mineral relative percentages. The reflectance spectra of each mixture have been analyzed both qualitatively (using the software ORIGIN®) and quantitatively applying the Modified Gaussian Model (MGM, Sunshine et al., 1990) algorithm. In particular, the spectral parameter variations of each absorption band have been evaluated versus the volumetric FeO% content in the PL phase and versus the PL modal abundance. This delineated calibration curves of composition vs. spectral parameters and allow implementation of spectral libraries. Furthermore, the trends derived from terrestrial analogues here analyzed and from analogues in the literature have been applied for the interpretation of hyperspectral images of both plagioclase-rich (Moon) and plagioclase-poor (Mars) bodies.

Efficacy and Safety of Ticagrelor for Long-term Secondary Prevention of Atherothrombotic Events in Relation to Renal Function: Insights from the PEGASUS TIMI-54 trial

Aims: We evaluated the relationship of renal function and ischaemic and bleeding risk as well as the efficacy and safety of the P2Y12 platelet receptor inhibitor ticagrelor in stable patients with prior myocardial infarction (MI). Methods & Results: Patients with a history of MI 1-3 years prior from the Prevention of Cardiovascular Events in Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin (PEGASUS)-TIMI 54 were stratified based on estimated glomerular filtration rate (eGFR), with<60 ml/min/1.73m2 prespecified for analysis of the effect of ticagrelor on the primary efficacy composite of cardiovascular death, MI, or stroke (MACE) and the primary safety endpoint of TIMI major bleeding. Of 20,898 patients, those with eGFR<60 (N=4,849, 23.2%) had a greater risk of MACE at 3 years relative to those without, which remained significant after multivariable adjustment (HRadj 1.54, 95% CI 1.27–1.85, p<0.001). The relative risk reduction in MACE with ticagrelor was similar in those with eGFR<60 (ticagrelor pooled vs. placebo: HR 0.81; 95% CI 0.68–0.96) vs. ≥60 (HR 0.88; 95% CI 0.77–1.00, pinteraction=0.44). However, due to the greater absolute risk in the former group, the absolute risk reduction with ticagrelor was higher: 2.7% vs. 0.63%. Bleeding tended to occur more frequently in patients with renal dysfunction. The absolute increase in TIMI major bleeding with ticagrelor was similar in those with and without eGFR<60 (1.19% vs. 1.43%), whereas the excess of minor bleeding tended to be more pronounced (1.93% vs. 0.69%). Conclusion: In patients with a history of MI, patients with renal dysfunction are at increased risk of MACE and consequently experience a particularly robust absolute risk reduction with long-term treatment with ticagrelor.

Determinants of biological activity of nanomaterials in innate immunity cells: the role of aspect ratio, environmental contaminants and protein corona

As defined by the European Union, “ ’Nanomaterial’ (NM) means a natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or agglomerate, where, for 50 % or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm-100 nm ” (2011/696/UE). Given their peculiar physico-chemical features, nanostructured materials are largely used in many industrial fields (e.g. cosmetics, electronics, agriculture, biomedical) and their applications have astonishingly increased in the last fifteen years. Nanostructured materials are endowed with very large specific surface area that, besides making them very useful in many industrial processes, renders them very reactive towards the biological systems and, hence, potentially endowed with significant hazard for human health. For these reasons, in recent years, many studies have been focused on the identification of toxic properties of nanostructured materials, investigating, in particular, the mechanisms behind their toxic effects as well as their determinants of toxicity. This thesis investigates two types of nanostructured TiO2 materials, TiO2 nanoparticles (NP), which are yearly produced in tonnage quantities, and TiO2 nanofibres (NF), a relatively novel nanomaterial. Moreover, several preparations of MultiWalled Carbon Nanotubes (MWCNT), another nanomaterial widely present in many products, are also investigated.- Although many in vitro and in vivo studies have characterized the toxic properties of these materials, the identification of their determinants of toxicity is still incomplete. The aim of this thesis is to identify the structural determinants of toxicity, using several in vitro models. Specific fields of investigation have been a) the role of shape and the aspect ratio in the determination of biological effects of TiO2 nanofibres of different length; b) the synergistic effect of LPS and TiO2 NP on the expression of inflammatory markers and the role played therein by TLR-4; c) the role of functionalization and agglomeration in the biological effects of MWCNT. As far as biological effects elicited by TiO2 NF are concerned, the first part of the thesis demonstrates that long TiO2 nanofibres caused frustrated phagocytosis, cytotoxicity, hemolysis, oxidative stress and epithelial barrier perturbation. All these effects were mitigated by fibre shortening through ball-milling. However, short TiO2 NF exhibited enhanced ability to activate acute pro-inflammatory effects in macrophages, an effect dependent on phagocytosis. Therefore, aspect ratio reduction mitigated toxic effects, while enhanced macrophage activation, likely rendering the NF more prone to phagocytosis. These results suggest that, under in vivo conditions, short NF will be associated with acute inflammatory reaction, but will undergo a relatively rapid clearance, while long NF, although associated with a relatively smaller acute activation of innate immunity cells, are not expected to be removed efficiently and, therefore, may be associated to chronic inflammatory responses. As far as the relationship between the effects of TiO2 NP and LPS, investigated in the second part of the thesis, are concerned, TiO2 NP markedly enhanced macrophage activation by LPS through a TLR-4-dependent intracellular pathway. The adsorption of LPS onto the surface of TiO2 NP led to the formation of a specific bio-corona, suggesting that, when bound to TiO2 NP, LPS exerts a much more powerful pro-inflammatory effect. These data suggest that the inflammatory changes observed upon exposure to TiO2 NP may be due, at least in part, to their capability to bind LPS and, possibly, other TLR agonists, thus enhancing their biological activities. Finally, the last part of the thesis demonstrates that surface functionalization of MWCNT with amino or carboxylic groups mitigates the toxic effects of MWCNT in terms of macrophage activation and capability to perturb epithelial barriers. Interestingly, surface chemistry (in particular surface charge) influenced the protein adsorption onto the MWCNT surface, allowing to the formation of different protein coronae and the tendency to form agglomerates of different size. In particular functionalization a) changed the amount and the type of proteins adsorbed to MWCNT and b) enhanced the tendency of MWCNT to form large agglomerates. These data suggest that the different biological behavior of functionalized and pristine MWCNT may be due, at least in part, to the different tendency to form large agglomerates, which is significantly influenced by their different capability to interact with proteins contained in biological fluids. All together, these data demonstrate that the interaction between physico-chemical properties of nanostructured materials and the environment (cells + biological fluids) in which these materials are present is of pivotal importance for the understanding of the biological effects of NM. In particular, bio-persistence and the capability to elicit an effective inflammatory response are attributable to the interaction between NM and macrophages. However, the interaction NM-cells is heavily influenced by the formation at the nano-bio interface of specific bio-coronae that confer a novel biological identity to the nanostructured materials, setting the basis for their specific biological activities.

Nanotossicologia dei quantum dot di CdS in linee cellulari umane

Le nanotecnologie sono un settore emergente in rapida crescita, come dimostra l'esplosione del mercato dei prodotti ad esso collegati. I quantum dot di cadmio solfuro (CdS QD) sono ampiamente utilizzati per la produzione di materiali semiconduttori e dispositivi optoelettronici; tuttavia, non sono ancora completamente chiari gli effetti di questi nanomateriali sulla salute umana. Questo lavoro di dottorato si pone l'obbiettivo di definire il potenziale citotossico e genotossico dei CdS QD in linee cellulari umane e definirne il meccanismo implicato. A questo scopo, essendo il fegato uno dei principali organi di accumulo del cadmio e dei nanomateriali a base di cadmio, è stata utilizzata la linea cellulare HepG2 derivante da un epatocarcinoma umano. È stato evidenziato, in seguito all'assorbimento, da parte delle cellule, dei CdS QD, un effetto citotossico, con conseguente modulazione dell'espressione genica di una serie di geni coinvolti sia nei processi di rescue (autofagia, risposta allo stress) sia in quelli di morte cellulare programmata. È stato, inoltre, dimostrata l'assenza di un rilevante effetto genotossico dipendente da questi nanomateriali. Infine, è stato osservato che cellule esposte ai CdS QD presentano mitocondri con un potenziale di membrana alterato, con conseguente alterazione della funzionalità di tale organello, pur conservando l'integrità del DNA mitocondriale.

Monitoring inflammation and airway remodeling by FMT in a chronic asthma model

Asthma is a multifactorial disease for which a variety of mouse models have been developed. A major drawback of these models is represented by the transient nature of the airway pathology peaking 24 to 72 hours after challenge and resolving in 1 to 2 weeks. The objective of this study is to characterize the temporal evolution of pulmonary inflammation and remodeling in a recently described mouse model of chronic asthma (8 week treatment with 3 allergens relevant for the human pathology: Dust mite, Ragweed, and Aspergillus; DRA). We studied the DRA model taking advantage of fluorescence molecular tomography (FMT) imaging using near-infrared probes to non-invasively evaluate lung inflammation and airway remodeling. At 4, 6, 8 or 11 weeks, cathepsin- and metalloproteinase-dependent fluorescence was evaluated in vivo. A subgroup of animals, after 4 weeks of DRA, was treated with Budesonide (100 µg/kg intranasally) daily for 4 weeks. Cathepsin-dependent fluorescence in DRA-sensitized mice resulted significantly increased at 6 and 8 weeks, and was markedly inhibited by budesonide. This fluorescent signal well correlated with ex vivo analysis such as bronchoalveolar lavage eosinophils and alveolar cell infiltration. Metalloproteinase-dependent fluorescence was significantly increased at 8 and 11 weeks, nicely correlated with collagen deposition, as evaluated histologically by Masson’s Trichrome staining, and airway epithelium hypertrophy, and was also partly inhibited by budesonide. In conclusion, FMT proved suitable for longitudinal study to evaluate asthma progression, both in terms of inflammatory cell infiltration and airway remodeling, allowing the determination of treatment efficacy in a chronic asthma model in mice.

Caratterizzazione dei fenotipi e della risposta infiammatoria delle vie aeree nell'asma da isocianati

RIASSUNTO Premesse: Nonostante l’asma sia stata considerata per anni come un’unica malattia, studi recenti ne dimostrano l’eterogeneità. L’intento di caratterizzare tale eterogeneità ha condotto a studiare molteplici sottogruppi ovvero “fenotipi”. Nell’asma comune questo approccio è stato utilizzato da svariati anni, meno invece nell’asma occupazionale. Poco è noto anche riguardo alle caratteristiche della risposta infiammatoria nel corso dei test di provocazione bronchiale specifici (SIC) con isocianati valutata con metodiche non invasive; in particolare l’origine dell’incremento di ossido nitrico misurato ad un flusso espiratorio di 50 ml/s (FeNO50) precedentemente riscontrato, se sia alveolare o bronchiale, i livelli di dimetilarginina asimmetrica (ADMA) e la temperatura dell’aria espirata (EBT). Scopi dello studio: 1) verificare se anche per l’asma occupazionale (OA) da isocianati siano individuabili dei fenotipi o se essa ne rappresenti uno unico 2) studiare l’infiammazione delle vie aeree sperimentalmente indotta tramite:  la misurazione dell’NO frazionato mediante i parametri “flow-independent” che stimano sia la regione alveolare, ovvero la concentrazione di NO alveolare (CaNO), che la regione bronchiale ovvero il flusso di NO a livello bronchiale (JawNO), la concentrazione di NO a livello della parete bronchiale (CawNO) e la diffusione di NO all’interfaccia lume-parete bronchiale (DawNO);  la misurazione dell’ADMA nel condensato dell’aria esalata (EBC);  la misurazione dell’EBT. Materiali e metodi: Per lo studio sulla fenotipizzazione dell’asma da isocianati sono stati esaminati pazienti risultati positivi al test di provocazione bronchiale specifico con isocianati nel periodo compreso tra il 1988 e il 2013. Mediante l’utilizzo di un approccio multivariato dato dall’analisi gerarchica dei cluster e di un ampio pool di variabili appropriate abbiamo studiato se i soggetti affetti da asma professionale da isocianati rappresentino uno o più cluster. Mediante un altro approccio multivariato, dato dall’analisi delle k-medie, si sono individuate le caratteristiche che differenziano in maniera significativa i soggetti distribuiti nei diversi cluster. Per il secondo scopo dello studio dal 2012 al 2015 abbiamo reclutato soggetti afferiti presso il nostro centro per sospetta asma professionale. In questi pazienti in corso di sham-test e di SIC con isocianati fino a 24 post test sono stati monitorati e misurati: la funzionalità respiratoria incluso il test di provocazione bronchiale aspecifico con metacolina, l’NO frazionato, l’ADMA nell’EBC e l’EBT. Risultati: L’utilizzo dell’analisi gerarchica dei cluster ci ha portati a stabilire che i 187 pazienti studiati non costituiscono un unico gruppo omogeneo ma possono essere suddivisi in 3 cluster. L’applicazione poi del metodo multivariato delle k-medie, su tre cluster, ci ha consentito di individuare due cluster di pazienti sensibilizzati a TDI con prevalente risposta late al SIC e un cluster di pazienti sensibilizzati a MDI con prevalente risposta early al SIC. I soggetti appartenenti ai due cluster dei TDI differiscono fra di loro in maniera significativa per l’età alla diagnosi e all’esordio dei sintomi respiratori, la distribuzione per sesso, il BMI, la distribuzione in quanto abitudine al fumo, l’IT, il FEV1 basale % del predetto, l’età di inizio esposizione, gli anni di latenza e la durata dell’esposizione. Per quanto riguarda invece lo studio del profilo infiammatorio delle vie aeree abbiamo reclutato 25 pazienti, 18 maschi e 7 femmine. Nel gruppo dei SIC-positivi FeNO50 è aumentato significativamente a 24 ore dal test (mediana 111.8 ppb [IQR, 167.5]; p<0.05) se confrontato con lo sham (58.6 ppb [74.7]). I livelli di JawNO hanno manifestato il medesimo time-course con un incremento significativo post 24 ore dall’esposizione (6.6 nL/s [81]; p <0.05) se confrontato con lo sham (3.3 nL/s [3.7]). Non sono state riscontrate significative variazioni negli altri parametri. Non sono state riscontrate significative variazioni dell’ADMA nell’EBC e dell’EBT in entrambi i gruppi. Conclusioni: L’asma da isocianati è una patologia eterogenea come l’asma comune. Gli elementi principali che differenziano i cluster di asma professionale da isocianati sono l’agente sensibilizzante e il tipo di risposta al SIC (cluster 3 vs cluster 1 e 2). Anche nell’ambito dell’asma indotta dallo stesso agente (TDI) si sono evidenziati due cluster in cui quello con peggiore funzionalità respiratoria è rappresentato da soggetti più anziani alla diagnosi e con maggiore durata dell’esposizione. I motivi per cui l’asma occupazionale risulta essere eterogenea possono essere un differente meccanismo d’azione dei monomeri o una diversa suscettibilità degli individui appartenenti ai diversi cluster sia in termini di insorgenza della malattia sia in termini di evoluzione della stessa. L’assetto infiammatorio delle vie aeree nel corso del SIC non si caratterizza nei soggetti sensibilizzati ad isocianati né con un incremento dell’ADMA né con un incremento dell’EBT. Si riscontra invece un aumento di FeNO50 dovuto esclusivamente ad un aumentato flusso di NO dalla parete bronchiale al lume. Abbiamo perciò dimostrato che la misurazione del FeNO50 nel corso del SIC può fornire informazioni aggiuntive al monitoraggio funzionale spirometrico, anche perché la broncoostruzione e la risposta infiammatoria delle vie aeree si sono rivelate dissociate.