2,349 research outputs found
Il ruolo dei saggi di ecogenotossicità per la protezione dell'ambiente e della salute umana.
No full textAntonio Tabucchi and the Visual Arts. Images, Visions, and Insights
No full textVisual images and imagery, optical metaphors
and iconic quotations are common features in
the literary work of Antonio Tabucchi, along
with references to the world of painting, photography,
and cinema. This book explores the
«iconic temptation» of the Italian author, pointing
out his visual strategies of representation
and poetic thought. By focusing on the visual
intertextuality of his fiction, it discusses questions
of style and content whilst also emphasizing
the role of images as a privileged means
of narrative knowledge and philosophical insight.
Drawing on the visual studies and on
postmodernist theory and criticism, this study
offers a comprehensive inquiry into the visual
poetics of one of Europe’s most innovative writers
«Il dono della parola». Conversazione con Edith Bruck
No full textIN THIS INTERVIEW, THE HUNGARIAN-BORN AUTHOR AND HOLOCAUST SURVIVOR EDITH BRUCK, DISCUSSES HER LIFELONG COMMITMENT TO TESTIMONY BOTH AS A PUBLIC SPEAKER AND A PROLIFIC NOVELIST, DEDICATED TO HANDING DOWN HER MEMORY TO FUTURE GENERATIONS. WHILE ANSWERING QUESTIONS ABOUT HER LITERARY CAREER, BRUCK ADDRESSES AESTHETIC AND ETHICAL ISSUES, SUCH AS THE VALUE OF POETRY IN HER LIFE, THE FEMININE QUALITY OF HER WRITING, THE CHALLENGES OF NARRATING OLD AGE, THE REASONS BEHIND THE UNPRECEDENT SUCCESS OF HER LATEST NOVEL AND THE IMPACT OF CLASS DIVIDE ON LITERARY CHOICES. SHE ALSO REFLECTS ON HER RELATIONSHIP WITH THE ITALIAN LANGUAGE AND SHARES GLIMPSES OF HER TRANSLATION ACTIVITY OF TWENTIETH-CENTURY HUNGARIAN POETS INTO ITALIAN
Lo stato nutrizionale nel paziente chirurgico. Elaborazione di un indice nutrizionale composto
No full textInhibition of Epstein Barr Virus LMP1 gene expression in B lymphocytes by antisense oligonucleotides: Uptake and efficacy of lipid-based and receptor-mediated delivery systems
No full textEpstein Barr Virus (EBV), is associated with an increasing number of lymphoid and epithelial malignancies. Among the genes expressed by EBV during latency, LMP1 plays a key role for growth transformation and immortalization of B lymphocytes. We have previously shown that antisense oligonucleotides (ONs) directed to LMP1 mRNA, effectively suppressed LMP1 gene expression and substantially reduced proliferation of the infected cells. The use of antisense phosphodiester oligonucleotides as therapeutic agents is limited by inefficient cellular uptake and intracellular transport to the target mRNA. We tested the ability of three cationic carriers internalized by different pathways, to increase the delivery of anti-LMP1-ON to their site of action in EBV-infected B lymphocytes. We report here that liposomes, dendrimers or transferrin-polylysine-conjugated ON were internalized by the cells at an extent several fold higher than that of the naked oligomers. However, only the delivery system exploiting the transferrin receptor pathway of internalization, was able to vectorize biologically active antisense LMP1-ON. © 2006
Macroscopic arc performance models with capacity constraints for within-day dynamic traffic assignment
No full textIn this paper, we present a new nonstationary link-based macroscopic arc performance model with capacity constraints, derived from an approximate solution to the simplified kinematic wave theory which based on the assumption, often introduced in the algorithms solving Dynamic Traffic Assignment, that the arc inflows are piecewise constant in time. Although the model does not require to introduce any spatial discretization, it is capable of taking implicitly into account the variability of the flow state along the arc accordingly to any concave fundamental diagram. To appreciate the effect of the approximation introduced, the model has been compared in terms of efficiency and effectiveness with three typical existing models, which have been to this end suitably modified and enhanced
Komani [Dalmace] (Albanie) : chronique de fouille 2009
No full textNallbani Etleva, Bitri Eduart, Bregu B., Haxhiraj E., Lela Surja, Meschini Marco, Naipi Pëllumb, Përzhita G., Tomas E. Komani [Dalmace] (Albanie) : chronique de fouille 2009. In: Mélanges de l'École française de Rome. Moyen-Age, tome 121, n°2. 2009. pp. 453-461
CHARACTERIZATION OF CELLULAR AND MOLECULAR MECHANISMS IN CELLULAR MODELS OF NEURONAL CEROID LIPOFUSCINOSES DISEASES
No full textCARATTERIZZAZIONE DEI MECCANISMI CELLULARI E MOLECOLARI IN MODELLI CELLULARI DI CEROIDO LIPOFUSCINOSI NEURONALI
Le Ceroido lipofuscinosi neuronali (NCL) rappresentano un gruppo di malattie neurodegenerative progressive ereditarie che colpiscono i bambini e gli adulti, caratterizzate da retinopatia, atassia e turbe della deambulazione, epilessia mioclonica farmaco resistente, decadimento cognitivo e morte precoce. Le NCL sono classificate secondo l’età di esordio della malattia in forma congenita, infantile, tardo infantile, giovanile e adulta. Le NCL sono considerate malattie da accumulo lisosomiale, dovuto alla presenza di depositi di materiale autofluorescente nei lisosomi della maggior parte delle cellule, tra cui neuroni, fibroblasti e linfociti.
Una comune classificazione delle NCL viene fatta sulla base del fenotipo clinico e delle manifestazioni biochimico-patologiche. Il fenotipo cellulare dovuto a difetti delle diverse proteine coinvolte, si presenta con tratti comuni che comprendono: alterati processi di apoptosi e autofagia, infiammazione cronica, squilibrio dei livelli di calcio all’interfaccia tra reticolo endoplasmico (ER)-citosol, deficit ossidativo ed alterato traffico dei lipidi. Ci sono evidenze riguardo un comune meccanismo d’azione delle proteine NCL, che potrebbero interagire a livelli multipli. Sebbene la causa genetica della maggior parte delle forme di NCL è stata identificata, i meccanismi che portano alla neurodegenerazione non sono noti, e non ci sono al momento terapie disponibili. L’ipotesi che meccanismi cellulari specifici possano essere alla base delle diverse forme di NCL consentirebbe approcci mirati nella terapia di queste patologie.
In questo lavoro ci siamo proposti di studiare i meccanismi cellulari e molecolari alla base di tre diverse forme di NCL attraverso l’utilizzo di linee cellulari di pazienti e sistemi cellulari modello. L’obiettivo della ricerca si è focalizzato sull’identificazione dei diversi meccanismi fisiopatologici che potrebbero essere coinvolti, almeno in parte, nelle malattie associate a mutazioni in tre diversi geni: CLN1 (forma infantile), CLN5 (tardo infantile) e CLN13-CTSF (forma adulta).
I nostri risultati indicano ruoli specifici delle tre diverse proteine affette.
Il coinvolgimento delle proteina CLN1 (INCL) nel metabolismo ossidativo
Abbiamo analizzato il compartimento mitocondriale nei fibroblasti con mutazione CLN1 e in un sistema in vitro di cellule umane di neuroblastoma, SH-SY5Y, che riproduce il fenotipo patologico osservato nelle mutazioni “Mediterranee” CLN1. Le analisi mitocondriali morfo/funzionali hanno mostrato un coinvolgimento del compartimento mitocondriale in entrambe i sistemi cellulari. I nostri dati sono in accordo con precedenti osservazioni in linee cellulari primarie di CLN1 dove si sono riscontrate anomalie nel numero, nella morfologia e nella localizzazione intercellulare dei mitocondri. Inoltre, un fenotipo simile è stato osservato in un buon modello cellulare con strutture neuronali. Processi mitocondriali alterati, lo stress ossidativo o l’induzione dell’apoptosi mitocondriale possono quindi verificarsi in pazienti CLN1 e potrebbero funzionare da target per piccole molecole nucleofiliche con proprietà antiossidanti ed effetti benefici sul processo neurodegenerativo della malattia.
Il ruolo della proteina CLN5 (LINCL) nell’alterato metabolismo dei lipidi
La malattia CLN5 è una delle forme tardo-infantile di NCL di cui non si conosce l’esatto meccanismo patogenetico. Somiglianze cliniche e neuropatologiche nelle NCL potrebbero essere dovute ad una ridondanza funzionale o alla cooperazione delle diverse proteine associate. E’ noto che l’aggiunta della proteina CLN8 (prodotta da un diverso gene associato a NCL) o CERS1 (ceramide sintetasi) corregge il fenotipo patologico di fibroblasti di pazienti CLN5.
Abbiamo dimostrato l’interazione molecolare tra CLN5, altre proteine NCL e le ceramidi in un sistema cellulare in vitro. In particolare abbiamo individuato nuove interazioni della proteina CLN5 con quattro ceramidi sintetasi (CERS1, CERS2, CERSS4, and CERS5) che sintetizzano le ceramidi, molecole con un ruolo centrale nel metabolismo dei lipidi in cellule di mammifero. La proteina CLN5, come CLN8 sembra risiedere nell’ER ma la sua presenza in questo compartimento è indipendente dalla proteina CLN8. I nostri risultati confermano che l’ER è un punto di snodo per la funzione e/o il traffico delle proteine NCL e che questo ruolo non implica un diretto legame con la membrana mitocondriale interna o i processi bioenergetici mitocondriali. Questi dati suggeriscono uno studio più approfondito delle ceramidi (livelli e meccanismi di sintesi) nella malattia CLN5, il possibile legame con l’attivazione di meccanismi di autofagia e mitofagia, e le conseguenze che potrebbe avere sul metabolismo dei lipidi e degli sfingolipidi.
Un ruolo chiave della proteina CLN13 (catepsina F) nei processi mediati da autofagia
Abbiamo caratterizzato a livello cellulare una nuova mutazione c.213+1G>C in CTSF-CLN13 associata ad una forma adulta di NCL, Kufs disease (KD) Type B. La mutazione altera lo splicing, rimuovendo l’esone 1 e producendo una forma tronca N-terminal di catepsina F, con una possibile perdita della sua funzione. Recentemente forme umane tronche di CTSF al sito N-terminal (Δ-CtsF) over-espresse in cellule HEK 293T sono state associate a inclusioni aggresoma-like ed alla presenza di proteine poliubiquitinate. Abbiamo dimostrato la presenza di strutture aggresoma-like nella biopsia cutanea e nei fibroblasti di pazienti con mutazione in CTSF. In quest’ultimi abbiamo inoltre osservato un’ aumento delle proteine autofagiche similmente a quanto osservato nelle cellule HEK 293T. Questi risultati indicano un’alterata autofagia e suggeriscono di indagare meglio sull’ inesplorata associazione tra autofagia, disfunzione del proteosoma e proteine polyUb nel danneggiamento delle cellule neuronali nelle forme adulte di NCL.
In conclusione, questo studio ha messo in evidenza meccanismi cellulari peculiari nella patologia di tre diverse forme di NCL, che sono per lo più rilevanti nei pazienti italiani. Inoltre, i nostri risultati dimostrano il coinvolgimento di specifici processi cellulari nella funzione patofisiologica delle proteine NCL. In prospettiva, questi meccanismi e le loro peculiarità dovranno essere meglio studiati per individuare vie cellulari che potrebbero essere targets specifici per lo sviluppo di trattamenti terapeutici mirati e specifici.CHARACTERIZATION OF CELLULAR AND MOLECULAR MECHANISMS IN CELLULAR MODELS OF NEURONAL CEROID LIPOFUSCINOSES DISEASES
The Neuronal Ceroid Lipofuscinoses (NCLs) represent a progressive group of inherited neurodegenerative diseases affecting children and adults, characterized by retinopathy leading to blindness, ataxia and gait abnormalities, drug-resistant progressive myoclonic epilepsy, mental deterioration, and an early death. NCL diseases were classified according to the age at disease onset (congenital, infantile, late infantile, juvenile, adult). They are considered lysosomal storage disorders, because of their characteristic accumulation of autofluorescent ceroid lipopigments, in lysosomes of most cells, including neurons, skin fibroblasts and blood lymphocytes.
The NCL share clinical manifestations, biochemistry, and pathology, hence their classification together. NCL protein deficiencies result in similar cell biologic phenotypes including dysregulation of apoptosis and autophagy, prolonged inflammation, disturbed endoplasmic reticulum–cytosol calcium balance, impaired oxidative metabolism, and abnormal lipid trafficking. There are evidences that NCL proteins are essential components of a common pathway and that they may interact at multiple locations. The possibility that individualized or specific mechanisms are more important in specific subtypes could offer more personalized approaches to cure. Although the genetic underpinnings of most forms of NCL have been identified, the pathway(s) in which neuronal death results in the severe degenerative phenotype remain unknown, and there is no available rational basis for treatments.
In this work we attempted to clarify the cellular and molecular mechanisms underlying three different forms of NCLs disease using patients’ material and cell models. Our focus was on the identification of distinctive pathways that could characterize, at least in part, the diseases associated with different genes: CLN1 (causing an Infantile type), CLN5 (determining a Late Infantile form) and CLN13-CTSF (responsible for Adult-NCL).
Our data indicate specific roles for the three affected proteins as follow.
The CLN1 protein (INCL) seems to be implicated in Oxidative metabolism pathways
We analyzed the mitochondrial compartment in CLN1 deficient skin fibroblasts and in an in vitro system of human neuroblastoma cells, SH-SY5Y, reproducing the pathological features seen in “Mediterranean” mutations in CLN1. Mitochondrial morpho/functional analysis showed an involvement of the mitochondrial compartment in both cellular systems. Our data confirmed previous observations reporting abnormalities in number, morphology and intracellular localization pattern of mitochondria in pathological primary cell lines. Moreover, a similar phenotype was seen in a good cellular model with neuronal-like structure. Mitochondrial dysfunctions could be, thus, involved in the pathogenesis of NCLs implying that mechanisms such as oxidative stress or apoptosis-induced via mitochondrial pathway can occur in the brain of CLN1 patients and offers further support to the possibility that small nucleophilic molecules with anti-oxidant properties might have beneficial effects on the neurodegenerative process of the disease.
The CLN5 protein (LINCL) is a player in abnormal lipid metabolism
The CLN5 disease is a variant form of late-infantile NCL and the exact pathogenetic mechanisms leading gene mutation to cause the disease is still unclear. Clinical and neuropathological similarities in NCL disorders may result from functional redundancy or co-operation of different NCL proteins (Vesa et al., 2002; Sleat et al., 2006) and it is known that the addition of CLN8p (the product of an additional NCL gene) or CERS1 (ceramide synthase) in CLN5-deficient patient fibroblast cells brings correction to the pathological phenotype.
We demonstrated the molecular interaction between CLN5, other NCL proteins, several lysosomal hydrolases and ceramides in an in vitro cellular system. In particular we found novel interactions between the CLN5 protein and four ceramide synthases (CERS1, CERS2, CERSS4, and CERS5) that synthesize ceramides, central molecules of sphingolipid metabolism in mammalian cells. Alike CLN8, also CLN5 seems to reside in the ER compartment but the presence of CLN5p in the ER is independent of the CLN8p. Our results confirmed that the ER is an important hub station for the function and/or trafficking of NCL proteins and that these role do not imply a direct connection with mitochondrial inner membrane or mitochondrial bioenergetics. These data foresee a deeper investigation of ceramides (levels, pathway of synthesis or both) in CLN5 disease, the possible connections with the activation of autophagy or mitophagy pathways, and the ensuing consequences on sphingolipid and phospholipid metabolisms.
The CLN13 protein (cathepsin F) has a key role in Autophagy mediated processes
We characterized at the cellular level a novel c.213+1G>C in CTSF associated with ANCL- Kufs disease (KD) Type B (CLN13). The mutation affects correct splicing, removing exon 1 and predicting a chopped N-terminus of cathepsin F, with a probable loss-of-function mechanism. Overexpression of N-terminus truncated forms of human cathepsin F (Δ-CtsF) in HEK 293T cells has recently been associated with features suggestive of aggresome-like inclusions and multifunctional polyubiquitinated proteins. We demonstrated in CTSF hypofunctioning primary cells from three CLN13 patients ultrastructural features resembling aggresome-like structures in skin biopsies. These features were biochemically replicated in cultured fibroblasts, where we observed an increase of autophagic proteins highly reminiscent of what had been seen in HEK 293T cells (Jerič et al., 2013). All these results were suggestive of dysregulated autophagy, and points to an as yet unexplored connection between autophagy, proteasomal dysfunction and polyUb proteins in triggering neuronal cell death in adult-forms of NCL.
To sum up, in this study we dissected at the cell level some of the specificities in three different forms of NCL pathology that are mostly relevant to Italian patients and our results pinpoint different steps in NCL disease and the involvement of specific cellular processes in the pathophysiological function of NCL proteins. In perspective, all these steps and their specificities should be further explored to define steps more relevant as those might represent specific targets for developing more rationale therapeutic options
Spillback congestion in dynamic traffic assignment: A macroscopic flow model with time-varying bottlenecks
No full textIn this paper, we propose a new model for the within-day Dynamic Traffic Assignment (DTA) on road networks where the simulation of queue spillovers is explicitly addressed, and a user equilibrium is expressed as a fixed-point problem in terms of are flow temporal profiles, i.e., in the infinite dimension space of time's functions. The model integrates spillback congestion into an existing formulation of the DTA based on continuous-time variables and implicit path enumeration, which is capable of explicitly representing the formation and dispersion of vehicle queues on road links, but allows them to exceed the are length. The propagation of congestion among adjacent arcs will be achieved through the introduction of time-varying exit and entry capacities that limit the inflow on downstream arcs in such a way that their storage capacities are never exceeded. Determining the temporal profile of these capacity constraints requires solving a system of spatially non-separable macroscopic flow models on the supply side of the DTA based on the theory of kinematic waves, which describe the dynamic of the spillback phenomenon and yield consistent network performances for given arc flows. We also devise a numerical solution algorithm of the proposed continuous-time formulation allowing for "long time intervals" of several minutes, and give an empirical evidence of its convergence. Finally, we carry out a thorough experimentation in order to estimate the relevance of spillback modeling in the context of the DTA, compare the proposed model in terms of effectiveness with the Cell Transmission Model, and assess the efficiency of the proposed algorithm and its applicability to real instances with large networks. (C) 2007 Elsevier Ltd. All rights reserved
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