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MOLECULAR PHYLOGENY, TAXONOMY AND BIOGEOGRAPHY OF THE "Haenydra" LINEAGE (COLEOPTERA, HYDRAENIDAE, GENUS Hydraena)

TRIZZINO, MARCO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
57%
The water beetle family Hydraenidae includes more than 1500 species worldwide, currently divided into four subfamilies: Hydraeninae, Ochthebiinae, Prosthetopinae and Orchymontinae. The majority of species are adapted for marginal life in the microscopic, mainly freshwater, aquatic world, feedeing dyatoms algae, even if details about the ecology of these beetles are poorly known. Most Hydraenidae species usually live in a layer of nearly stationary waters, where they adhere to the submerged stones within the fastest regions of cold, clean and fastflowing perennial streams. Hydraena Kugelann represents the largest genus within the water beetle family Hydraenidae, and in particular within Hydraeninae, with about 850 species widely distributed all over the world and several hundreds not yet described. In a recent cladistic analysis, based on morphological characters, Hydraena s.l. was split in two subgenera: Hydraenopsis Janssens (Gondwanian) and Hydraena s.str. (Laurasian). Moreover, within Hydraena s.str, some derived and well-supported monophyletic clades were recognised, and defined as “lineages”. Among them, the "Haenydra" Rey lineage, previously considered by many authors as a valid genus/subgenus, includes about 90 species distributed esclusively in western Palaearctic...

Rischio da ozono e stress climatico in alcune cenosi forestali costiere del Lazio meridionale

SALVATORI, ELISABETTA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.36%
Tesi di Dottorato di Ricerca in Scienze Ecologiche, XX Ciclo

Implicazioni funzionali, strutturali e farmacogenomiche dello splicing alternativo: approcci computazionali

FLORIS, MATTEO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
56.94%

Caratterizzazione ultrastrutturale e molecolare di esemplari mediterranei dei generi Hydrolithon e Pneophyllum (Corallinales, Rhodophyta)

MANCINI, SARA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
57%

Clinical relevance of free peritoneal tumor cells detection in gastric and colorectal cancer: a multiple molecular approach

ROSSI DEL MONTE, SIMONE
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
56.94%
Background Free disseminated peritoneal tumor cells derive from the detachment from primary cancer and may result in peritoneal carcinomatosis. Peritoneal lavage cytology has low sensitivity in detecting free peritoneal tumor cells; reverse-transcriptase polymerase reaction showed higher sensitivity but low specificity. Our study introduces the combination of the RT-PCR, the immunomagnetic enrichment and the immunofluorescence for the detection of peritoneal free tumor cells. Materials and Methods Samples of peritoneal lavage were collected from 22 gastric and 45 colorectal cancer patients; samples were also obtained from 6 patients who underwent abdominal surgery for non-malignant diseases. CEA and CK20 mRNA levels were quantified using a real-time qRT-PCR system. Immunomagnetic enrichment followed by immunofluorescence analysis was performed using monoclonal antibody against the pan-epithelial marker EpCAM/CD326 and polyclonal antibodies against the carcinoembryonic antigen. Results For gastric carcinoma the positivity rate for cytology, immunofluorescence and qRT-PCR was 14%, 18% and 77% respectively; for colorectal carcinoma the positivity rate for cytology, immunofluorescence and qRT-PCR was 0%, 18% and 44% respectively. All patients except one when positive at immunofluorescence were also positive at qRT-PCR. All samples of peritoneal lavage from the control group resulted negative for cytology...

NUOVI TRATTAMENTI PER IL DOLORE INFIAMMATORIO E NEUROPATICO

COBIANCHI, STEFANO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
57.25%
New treatments for neuropathic pain Stefano Cobianchi, Institute of Neuroscience, CNR, Rome (Italy). Experiment 1: Botulinum neurotoxins. Aim. Botulinum neurotoxins have been successfully used in clinical practice for the treatment of dystonias and a number of syndromes associated to hyperfunctioning of cholinergic terminals. Recent data support the use of Botulinum neurotoxins (BoNTs) as new therapeutic agents in pain relief. It has been demonstrated that the Botulinum neurotoxin serotype-A is able to induce analgesia in inflammatory pain conditions (1). In this study we investigated the effects of two different serotypes, A and B (BoNT/A and BoNT/B), in the development and recovering from neuropathic pain in mice subjected to the sciatic nerve ligation (Chronic Constriction Injury, Bennett and Xie model) (2, 3). Methods. Mice were subcutaneously injected into the plantar surface of both hindpaws either with BoNT/A (two doses: 7.5 or 15 pg/paw), BoNT/B (3.75 pg/paw) or saline, on different days before and after CCI. The temporal trend of neuropathy over a long time interval (80 days) was analyzed measuring the mechanical allodynic response to the Dynamic Aesthesiometer Test. Functional recovery of the injured paw was followed examining the mice walking pattern...

Nitric Oxide Determines Mesodermic Differentiation of Mouse Embryonic Stem Cells by Activating Class IIa Histone Deacetylases

SPALLOTTA, FRANCESCO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
56.94%
In human endothelial cells, nitric oxide (NO) results in class IIa histone deacetylases (HDACs) activation and marked histone deacetylation. It is unknown whether similar epigenetic events occur in embryonic stem cells (ESC) exposed to NO and how this treatment could influence ESC therapeutic potential during tissue regeneration. This study reports that the NO-dependent class IIa HDACs subcellular localization and activity decreases the global acetylation level of H3 histones in ESC and that this phenomenon is associated with the inhibition of Oct4, Nanog, and KLF4 expression. Further, a NO-induced formation of macromolecular complexes including HDAC3, 4, 7, and protein phosphatase 2A (PP2A) have been detected. These processes correlated with the expression of the mesodermalspecific protein brachyury (Bry) and the appearance of several vascular and skeletal muscle differentiation markers. These events were abolished by the class IIa-specific inhibitor MC1568 and by HDAC4 or HDAC7 short interfering RNA (siRNA). The ability of NO to induce mesodermic/cardiovascular gene expression prompted us to evaluate the regenerative potential of these cells in a mouse model of hindlimb ischemia. We found that NO-treated ESCs injected into the cardiac left ventricle selectively localized in the ischemic hindlimb and contributed to the regeneration of muscular and vascular structures. These findings establish a key role for NO and class IIa HDACs modulation in ESC mesodermal commitment and enhanced regenerative potential in vivo.

Role of the mesothelial microenvironment in the peritoneal dissemination of gastric and colorectal cancers

RANIERI, DANILO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
66.8%
La disseminazione tumorale sistemica è considerato uno dei passaggi cruciali della carcinosi peritoneale, complicanza che nel carcinoma dello stomaco e del colon-retto si manifesta con elevata prevalenza anche dopo il trattamento chirurgico di resezione del tumore (Sadeghi et al. 2000, Jayne et al. 2002). I meccanismi di disseminazione peritoneale prevedono l’intervento di una sequenza di eventi tra cui si annoverano il distacco di sottopopolazioni di cellule neoplastiche dalla massa del tumore primario, il loro passaggio nel fluido peritoneale, la susseguente colonizzazione del mesotelio e la formazione di una nuova massa tumorale. Uno dei passaggi critici che condiziona lo sviluppo della recidiva peritoneale consiste nell’adesione ai foglietti mesoteliali delle cellule tumorali esfoliate dal carcinoma. In questo processo risultano coinvolti diversi meccanismi molecolari imperniati soprattutto sul ruolo e sulle caratteristiche delle cellule tumorali (Harada et al. 2001, Kajiyama et al. 2008, Saito et al. 2010) mentre il contributo della controparte mesoteliale è stato, fino ad oggi, meno studiato, nonostante sembri anch’esso accreditato di un ruolo primario (Casey et al. 2003, Takatsuki et al. 2004, Alkhamesi et al. 2005). L’analisi dell’adesione tumorale al mesotelio è basata sull’impiego di modelli sperimentali sviluppati in vitro; essi...

“Modulation of NKG2D and DNAM-1 activating receptors and their ligands during HIV-1 infection”.

MATUSALI, GIULIA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
66.97%
Natural killer (NK) cells play a critical role in host defense against viral infections. Chronic HIV-1 infection is associated with an accumulation of dysfunctional NK cell, that unsuccessfully control viral replication. However, the underlying mechanisms for this NK cell dysfunction are poorly understood. NK cells do not express an antigen specific receptor, as do other lymphocytes. Instead, NK cells encode a variety of different activating and inhibitory receptors and NK cell activation is dependent on a delicate balance between signals of opposite sign elicited by the multiple NK cell receptor–ligand interactions that follow NK cell–target cell interaction. The goal of my PhD project was to analyze the role of NK cell activating pathways upon HIV-1 infection. Specifically, I studied the modulation of the activating receptor NKG2D with particular interest on the mechanism of release, namely shedding, of its ligands (NKG2DLs) during HIV-1 infection in in vitro cell systems as well as in HIVinfected patients. Moreover, I investigated the modulation by viral proteins, such as Nef and Vpu, of PVR (Poliovirus Receptor, CD155, Necl-5) a ligand for another stimulatory receptor, DNAM-1 (DNAX accessory molecule-1 or CD226).The final goal of this work was to identify novel factors that regulate the function of immune responses against HIV-1 and that could provide new prognostic biomarkers and innovative antiviral strategies.; The work was supported by grants of the Italian Ministry of Health...

Energetics of Cerebral Cortex: Metabolic Modeling and In Vivo NMR

DI NUZZO, MAURO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
56.94%
The energy metabolism of cerebral cortex adapts to the increase in metabolic demand which occurs during enhanced cortical activity (e.g. sensory stimulation). This contributes to the generation of the imaging and spectroscopic signals that are utilized to monitor and appraise the function of the brain in situ. Importantly, the simple paradigm of “neuronal activity” is insufficient to interpret experimental outcomes, as what is observed depends on the balance between (i) activity patterns, whether excitatory or inhibitory; (ii) information processing mechanisms, specifically input/output or synaptic/spiking activity; (iii) stimulation of cell-specific (primarily neuronal and astrocytic) functional and metabolic pathways. Understanding the basis of the metabolic response of the cortical tissue to stimulation (i.e. neurometabolic coupling) is an important goal for neurosciences. In the present work, I studied the coupling between activity and energy metabolism of the human cerebral cortex by combining theoretical and experimental approaches. First, I adapted and used the information about the energy consumed by cortical signaling processes in order to develop a kinetic model of carbohydrate metabolism (Chapters 1 and 2). By encompassing the current knowledge about the regulation of energy supply and demand in cortical tissue...

‘PROBIOTIC BACTERIA ADMINISTRATION AS AN IMMUNOMODULATORY APPROACH FOR FOOD ALLERGY TREATMENT: PRECLINICAL STUDIES IN MOUSE MODELS’

SCHIAVI, ELISA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
66.36%
Studi clinici ed epidemiologici hanno messo in evidenza l’associazione tra l’aumentata prevalenza delle malattie allergiche nei Paesi occidentali e la ridotta esposizione ai germi e/o l’ alterazione delle comunità microbiche intestinali, il cui metabolismo e composizione risultano cruciali per lo sviluppo e il mantenimento delle funzioni immunitarie. Riportare all’equilibrio il microbioma intestinale potrebbe rappresentare una strategia preventiva e/o terapeutica per le allergie, in particolare quelle alimentari, per le quali non esistono ad oggi misure sicure ed efficaci in tal senso. Di qui, il razionale dell’utilizzo dei batteri probiotici, organismi vivi che conferiscono effetti benefici all’ospite (tra cui la loro attività immunomodulante) quando somministrati in concentrazioni adeguate. Poiché, nonostante i presupposti, gli studi clinici in pazienti allergici trattati con probiotici a fini di prevenzione e terapia hanno prodotto risultati controversi, studi in modelli animali di allergia possono fornire informazioni preziose per chiarire gli effetti e i meccanismi di azione dei batteri probiotici, non altrimenti reperibili negli studi su soggetti umani. Lo scopo del lavoro svolto durante i tre anni accademici del Corso di Dottorato in Scienze Immunologiche (XXV ciclo) nel laboratorio della Dr.ssa Gabriella Di Felice...

Palaeobiogeography and evolution of insular bovids: ecogeographic patterns of body mass variation and morphological changes

ROZZI, ROBERTO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
56.94%
The study of the plants and animals that live on island has been a frequent key to understanding the processes of evolution that determine biotic diversity globally. Insular endemic mammals represent a special ground for the study of evolutionary mechanisms and speciation processes in response to the special characteristics of island environments. Endemic bovids are intriguing elements of insular faunas and offer an extensive and diversified sample for exploring patterns of insular evolution of large-sized mammals. This thesis provides the first comprehensive study on the evolution of extinct and living insular bovids, exploring the selective biotic and abiotic factors that influenced ecogeographic patterns of body mass variation and peculiar morphological changes (e.g., hypsodonty and low-gear locomotion) of these taxa. I show that the majority of island bovids, as large mammals, do follow the main prediction of the island rule, showing a body size reduction, and that ecological release and resource limitation are the main factors influencing body size evolution of these taxa. My results indicate that hypsodonty (increase in molar crown height), a quite common morphological trend in insular artiodactyls, is shared by the majority of insular bovids independently from the abrasiveness of the current diet. The evolution of this feature appear to result from an expansion of the dietary niche under resource limitation...

BASI BIOLOGICHE DELLE CARDIOPATIE CONGENITE

CONSOLI, FEDERICA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.38%

Molecular mechanisms of HMGB1, a key mediator of inflammation, and role in diseases such as cancer and diabetes mellitus

SENATORE, CINZIA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
57%

NM23: UNA PROTEINA CON ATTIVITA" NUCLEOSIDE DIFOSFATO CHINASICA E ANTIMETASTATICA. Studi strutturali sull'enzima da Dictyostelium discoideum e studi funzionali sull'enzima umano.

Egistelli, Lorenza
Fonte: La Sapienza Publicador: La Sapienza
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.41%
Giovanni Antonini Dip. Biologia Universita' di Roma 3 V.le G. Marconi, 446 00146 Roma; Nazzareno Capitanio Dip. Scienze Biomediche Universita'di Foggia Via Gramsci, 71100 Foggia; Maurizio Paci Dip. di Scienze e Tecnologie Chimiche Universita' di Roma "Tor Vergata" Via della Ricerca Scientifica 00133 Roma

Metabolismo fermentativo nel lievito K.lactis: regolazione ossigeno-dipendente e autoregolazione del gene KlPDC1

MICOLONGHI, CHIARA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.36%
Nel lievito non convenzionale Kluyveromyces lactis, il gene KlPDC1 codifica per l'unica piruvato decarbossilasi, che catalizza la prima reazione della via fermentativa, la conversione del piruvato in acetaldeide. KlPDC1 è soggetto a diversi meccanismi di regolazione trascrizionale, tra cui l'induzione da glucosio, la repressione da etanolo e la regolazione ossigeno-dipendente; inoltre, il gene KlPDC1 è soggetto ad autoregolazione, un meccanismo di regolazione feedback in cui la proteina Pdc1 reprime la propria espressione. Il presente lavoro di dottorato ha avuto come oggetto lo studio di due di questi meccanismi: l'autoregolazione e la regolazione ossigeno-dipendente. Secondo il modello da noi elaborato, nel meccanismo di autoregolazione la proteina Pdc1 interagisce con l'attivatore trascrizionale Rag3, impedendone il legame al promotore di KlPDC1 e determinando una diminuzione dell'espressione del gene. L'interazione fisica tra le due proteine è stata dimostrata attraverso esperimenti di co-immunoprecipitazione e saggi two hybrid, mentre è ancora da chiarire quale sia il compartimento cellulare (nucleo o citoplasma) in cui ha luogo tale interazione. Esperimenti di real time pcr hanno permesso di rilevare delle variazioni nei livelli di espressione di RAG3...

Role of microRNAs in Duchenne Muscular Dystrophy and in muscle differentiation

CACCHIARELLI, DAVIDE
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
66.79%
Duchenne Muscular Dystrophy (DMD), caused by mutations in the dystrophin gene, is one of the most severe myopathies. Among different therapeutic strategies, exon skipping allows the rescue of dystrophin synthesis through the production of a shorter but functional mRNA. Making use of exon skipping strategy we demonstrated that in DMD, the absence of dystrophin at the sarcolemma delocalizes and downregulates Nitric Oxide Synthase (nNOS); this alters HDAC2 S-nitrosylation and its chromatin association. We show that the differential HDAC2 nitrosylation state in Duchenne versus wild-type conditions deregulates the expression of a specific subset of microRNA genes crucial in DMD physiopathology. Namely, we identified miR-1 as regulator of the redox state of the cell through modulation of the G6PD enzyme while miR-29 controls the fibrotic process targeting extracellular matrix proteins. We also show that, at variance with other myomiRs, miR-206 and miR-31 escape from the dystrophin-nNOS control being expressed in activated satellite cells before dystrophin expression. In these cells, miR-206 contributes to muscle regeneration through repression of the satellite specific factor Pax7, while miR-31 inhibits the early expression of dystrophin by directly repressing its mRNA. Finally...

Membrane-active derivatives of the frog skin peptide Esculentin-1 against relevant human pathogens

LUCA, VINCENZO
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
57.05%
Candida albicans represents one of the most prevalent species causing life-threatening fungal infections. Current treatments to defeat Candida albicans have become quite difficult, due to their toxic side effects and the emergence of resistant strains. Antimicrobial peptides (AMPs) are fascinating molecules with a potential role as novel anti-infective agents. However, only a few studies have been performed on their efficacy towards the most virulent hyphal phenotype of this pathogen. The purpose of this work is to evaluate the anti-Candida activity of the N-terminal 1–18 fragment of the frog skin AMP esculentin- 1b, Esc(1–18), under both in vitro and in vivo conditions using Caenorhabditis elegans as a simple host model for microbial infections. Our results demonstrate that Esc(1–18) caused a rapid reduction in the number of viable yeast cells and killing of the hyphal population. Esc(1–18)revealed a membrane perturbing effect which is likely the basis of its mode of action. Esc(1-18) is able (1) to kill both growing stages of Candida; (2) to promote survival of Candida-infected living organisms and (3) to inhibit transition of these fungal cells from the roundish yeast shape to the more dangerous hyphal form at sub-inhibitory concentrations. Pseudomonas aeruginosa is an opportunistic bacterial pathogen that forms sessile communities...

FLORA, VEGETAZIONE E INDICATORI MACROFITICI DEI LAGHI VULCANICI D’ITALIA

AZZELLA, MATTIA MARTIN
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.36%
Le acque dolci rappresentano meno dello 0,8% della superficie terrestre e ospitano una grande varietà di forme di vita: circa il 6% delle specie fin’ora descritte vive in acqua dolce (Hawksworth & Kalin-Arroyo, 1995). Nonostante i sistemi di acque dolci svolgano un ruolo fondamentale nella biosfera e i numerosi servizi da essi forniti siano un cardine per l’economia umana, la loro disponibilità sta drasticamente diminuendo e lo sfruttamento della risorsa idrica aumenta in modo costante nel tempo (Jackson et al., 2001). Lo scopo di questo studio è l'analisi della componente macrofitica dei laghi vulcanici italiani. Con il termine macrofite si individua la componente produttiva primaria macroscopica dei sistemi acquatici, mentre diatomee e fitoplancton ne rappresentano la porzione microscopica. Esistono molte classificazioni delle macrofite basate su elementi strutturali, su forme di crescita o caratteri funzionali (Pearsal, 1918; den Hartog & Segal, 1964; Hutchinson, 1975; Mäkirinta, 1978; den Hartog & van der Velde, 1988;Buotin & Keddy, 1993; Willby et al., 2000; Lacoul & Freedman, 2006). Nel presente lavoro si è utilizzata una classificazione di tipo funzionale che non si limita ad analizzare solo le macrofite sommerse, ma include anche la componente emersa composta da elofite e piante legnose...

Aspetti del sistema nuziale del Punteruolo rosso delle palme (Rhynchophorus ferrugineus): un approccio molecolare e bioinformatico.

BELVEDERE, SILVIA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
IT
Relevância na Pesquisa
66.38%
Il Punteruolo rosso delle palme, Rhynchophorus ferrugineus, Olivier (Curculionoidea, Dryophtoridae), è un coleottero originario del Sud-Est asiatico e della Melanesia invasivo in Medio Oriente ed in quasi tutti i paesi del bacino del Mediterraneo, compresa l'Italia. Il fitofago arreca ingenti danni a numerose specie di Arecaceae, tra cui molte palme di interesse economico. Le attuali azioni di controllo integrato, adottate per contenerne l'espansione, si sono rivelate finora insufficienti anche perché manca una approfondita conoscenza del sistema nuziale dell'insetto, ed il suo grande successo riproduttivo è proprio una delle cause principali del enorme potenziale invasivo di questa specie dannosa. Obiettivo generale del progetto di dottorato è stato dunque lo studio di aspetti del mating system del Punteruolo rosso legati ad eventuali comportamenti poliandrici e fenomeni di selezione sessuale post-copulatoria. Sono stati eseguiti a questo scopo dei test di paternità, per mezzo di analisi genetiche e bioinformatiche, sulla prole di esperimenti di incrocio effettuati in laboratorio, in modo da verificare ipotesi alternative riguardanti il sistema nuziale della specie. Date le scarse informazioni genetiche disponibili su R. ferrugineus...