1,725,014 research outputs found
The P2Z purinoceptor: an intriguing role in immunity, inflammation and cell death
No full textAbstract
Many immune and inflammatory cells express a plasma membrane receptor for extracellular ATP, termed the P2Z purinoceptor, which appears to be coupled to a plasma membrane pore. The physiological role of such a molecule is generally unknown, except for the striking susceptibility to ATP-mediated cytotoxicity that it confers. The receptor is upregulated in human monocytes by interferon gamma and is also expressed during macrophage differentiation. Here, Francesco Di Virgilio discusses recent information on this receptor, and suggests a possible role for it in the immune and inflammatory response
La obra de Alicia Ziccardi desde el caleidoscopio de los estudios urbanos en América Latina
No full textEl objetivo del estudio introductorio es recorrer la obra de Alicia Ziccardi desde el caleidoscopio de su inscripción en los estudios urbanos latinoamericanos. No es posible desconocer que la Dra. Ziccardi es y ha sido una destacada referente en el área. De este modo, transitaremos sus aportes más importantes en diálogo con las preocupaciones del campo, en nuestra región.Fil: Di Virgilio, Maria Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Aristofane. Tesmoforiazuse. I Canti, a cura di Loredana Di Virgilio, Pisa-Roma, Fabrizio Serra Editore, 2025.
No full text
Chelation of cytoplasmic Ca2+ increses plasma membrane permeability in murine macrophages
No full textCytoplasmic free Ca2+ (Ca2+i) was chelated to 10-20 nM in the macrophage cell line J774 either by incubation with quin2 acetoxymethyl ester in the absence of external Ca2+ (Di Virgilio, F., Lew, P.D., and Pozzan, T. (1984) Nature 310, 691-693) or by loading [ethyl-enebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) into the cytoplasm via reversible permeabilization of the plasma membrane with extracellular ATP (Steinberg, T.H., Newman, A.S., Swanson, J.A., and Silverstein, SS.C. (1987) J. Biol. Chem. 262, 8884-8888; Di Virgilio, F., Meyer, B.C., Greenberg, S., and Silverstein, S.C. (1988) J. Cell Biol. 106, 657-666). After removal of ATP from the incubation medium, ATP-permeabilized Ca2+i-depleted macrophages recovered a near-normal plasma membrane potential which slowly depolarized over a 2-4 h incubation at low [Ca2+]i. In both ATP-treated and quin2-loaded cells, depolarization of plasma membrane potential was paralleled by an increase in plasma membrane permeability to low molecular weight aqueous solutes such as eosin yellowish (Mr 692), ethidium bromide (Mr 394), and lucifer yellow (Mr 463). This increased plasma membrane permeability was not accompanied by release of the cytoplasmic marker lactic dehydrogenase for incubations up to 4 h and was likely a specific effect of Ca2+i depletion since it was not caused by: (i) the mere incubation of macrophages with extracellular EGTA, i.e. at near-normal [Ca2+]i; and (ii) loading into the cytoplasm of diethylenetriaminepentaacetic acid, a specific chelator of heavy metals with low affinity for Ca2+. Treatment of Ca2+i-depleted cells with direct (phorbol 12-myristate 13-acetate) or indirect (platelet-activating factor) activators of protein kinase C prevented the increase in plasma membrane permeability. Down-regulation of protein kinase C rendered Ca2+i-depleted macrophages refractory to the protective effect of phorbol 12-myristate 13-acetate. This report suggests a role for Ca2+i and possibly protein kinase C in the regulation of plasma membrane permeability to low molecular weight aqueous solutes
Chelation of cytoplasmic Ca2+ increases plasma membrane permeability in murine macrophages
No full textCytoplasmic free Ca2+ (Ca2+i) was chelated to 10-20 nM in the macrophage cell line J774 either by incubation with quin2 acetoxymethyl ester in the absence of external Ca2+ (Di Virgilio, F., Lew, P.D., and Pozzan, T. (1984) Nature 310, 691-693) or by loading [ethyl-enebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) into the cytoplasm via reversible permeabilization of the plasma membrane with extracellular ATP (Steinberg, T.H., Newman, A.S., Swanson, J.A., and Silverstein, SS.C. (1987) J. Biol. Chem. 262, 8884-8888; Di Virgilio, F., Meyer, B.C., Greenberg, S., and Silverstein, S.C. (1988) J. Cell Biol. 106, 657-666). After removal of ATP from the incubation medium, ATP-permeabilized Ca2+i-depleted macrophages recovered a near-normal plasma membrane potential which slowly depolarized over a 2-4 h incubation at low [Ca2+]i. In both ATP-treated and quin2-loaded cells, depolarization of plasma membrane potential was paralleled by an increase in plasma membrane permeability to low molecular weight aqueous solutes such as eosin yellowish (Mr 692), ethidium bromide (Mr 394), and lucifer yellow (Mr 463). This increased plasma membrane permeability was not accompanied by release of the cytoplasmic marker lactic dehydrogenase for incubations up to 4 h and was likely a specific effect of Ca2+i depletion since it was not caused by: (i) the mere incubation of macrophages with extracellular EGTA, i.e. at near-normal [Ca2+]i; and (ii) loading into the cytoplasm of diethylenetriaminepentaacetic acid, a specific chelator of heavy metals with low affinity for Ca2+. Treatment of Ca2+i-depleted cells with direct (phorbol 12-myristate 13-acetate) or indirect (platelet-activating factor) activators of protein kinase C prevented the increase in plasma membrane permeability. Down-regulation of protein kinase C rendered Ca2+i-depleted macrophages refractory to the protective effect of phorbol 12-myristate 13-acetate. This report suggests a role for Ca2+i and possibly protein kinase C in the regulation of plasma membrane permeability to low molecular weight aqueous solutes
I DELEGATI CONGRESSUALI DI PARTITO
No full textQuesto numero monografico di «Polis» – curato da Paola Bordandini, Aldo Di Virgilio e Rosa Mulé – si interroga su alcuni aspetti delle trasformazioni dei partiti italiani, adottando una specifica prospettiva di ricerca: lo studio dei delegati congressuali, del loro profilo, dei loro atteggiamenti, della loro attività politica. La base dati utilizzata è frutto di una ricerca condotta con sistematicità, secondo standard metodologici esigenti e applicati con rigore. Si tratta di qualità che non sempre è facile veder accomunate e che, anche per questo, fanno della ricerca di cui si parla un unicum nella letteratura internazionale. Sulla base dei dati raccolti con questa importante ricerca, il numero 2/2011 di «Polis» presenta quattro articoli in cui si affrontano tematiche rilevanti nella letteratura politologica, nella vita di partito e nelle trasformazioni dell’arena politica, quali la cultura politica, la selezione dei candidati, la partecipazione politica all'interno dei partiti
Introduzione. L'anno del podestà forestiero
No full textIl 2012 è stato l’anno di Monti, il «podestà forestiero» al quale il presidente Giorgio Napolitano aveva affidato il compito di salvare l’Italia dal baratro finanziario e di restituire credibilità al paese nell’arena internazionale. Misurato sull’arco dell’intero anno, il bilancio del governo tecnico presenta luci e ombre: allontanato il pericolo del default, sono mancati invece risultati concreti sul versante della crescita economica. La «strana maggioranza» che ha sostenuto il governo Monti in Parlamento – Pdl, Pd e Udc – non ha fatto meglio. Nonostante la moral suasion di Napolitano, i partiti hanno perso un’altra occasione – l’ultima? – per attuare riforme istituzionali improrogabili e per mettere mano seriamente ai costi e ai privilegi della politica. Chi ha beneficiato di questa situazione è stato il Movimento 5 stelle, che mira a un rovesciamento di tutti gli equilibri politici. A fine 2012 le condizioni dell’Italia restano difficili. Lo sforzo di risanamento avviato a caro prezzo dal governo Monti può essere vanificato in poco tempo e il rischio che l’orologio del paese torni alle drammatiche settimane dell’autunno 2011 non è scongiurato
Introduction: the year of the external Podestà
No full textIn 2012, the spotlight was on Prime Minister Monti and his government of non-elected ministers. Early in the year, the new government’s economic policy was effective in stopping the international downgrading of the country’s credit rating. However, in terms of the entire year, the success of the Monti government appears less definitive. There were no clear achievements in terms of growth, and the structural features of the economy remained weak. Monti successfully initiated some reforms and policy changes, but there were failures as well. Furthermore, the “odd majority” (made up of the PdL, PD, and UdC) that supported Monti in Parliament performed more weakly than the government. The parties were to change the electoral law, reform the parliamentary institutions, cut costs, and reduce the privileges of the political class, but failed. Their inaction was accompanied by a series of scandals and crimes, all of which facilitated the emergence of new political forces, such as the Five Star Movement. When Monti eventually resigned in December 2012, President Napolitano called for new elections, and the parties redefined their proposals and lists. At the end of the year, the political and economic conditions of the country remained fragile
L’apparato digitale di Virgilio
No full textScopo principale del presente contributo è quello di descrivere le scelte effettuate e i criteri adottati nella costituzione dell'apparato e dell'edizione digitale Musisque Deoque di Virgilio, nonché di proporre una prima riflessione su analogie e differenze rispetto alle edizioni critiche 'tradizionali'. Sarà data particolare attenzione a tre aspetti principali: la tabella delle fonti, la selezione delle varianti, la tradizione indiretta di Virgilio
- …
