150 research outputs found
Antithrombotic therapy with rivaroxaban in five patients with paroxysmal nocturnal haemoglobinuria and thrombotic events
Five patients with paroxysmal nocturnal haemoglobinuria and thrombotic complications under oral antithrombotic treatment with vitamin K antagonist were switched to receive the direct oral anticoagulant rivaroxaban an factor Xa inhibitor. In all five patients haematological and biochemical parameters and adverse events were evaluated for a period of twelve months. Therapy with rivaroxaban was well tolerated in all cases and one patient showed a significant reduction of bleeding and transfusion requirement. All patients obtained a significant reduction in days of hospitalization with a consequent improvement in their quality of life after rivaroxaban treatment
Materiali compositi per impiego aeronautico e loro certificazione tramite prove sperimentali
Molte tecnologie moderne richiedono l'impiego di materiali che offrano peculiari combinazioni di diverse proprietà che non possono essere presenti contemporaneamente nei materiali di più tradizionale impiego, quali le leghe metalliche convenzionali, i ceramici ed i polimeri. Quanto ora affermato è particolarmente vero per i materiali impiegati nelle applicazioni aerospaziali, sottomarine, e nell'industria dei trasporti. Per esempio, gli ingegneri aeronautici sono alla continua ricerca di materiali strutturali che presentino basse densità e al contempo buona resistenza, buona rigidezza, buona resistenza all'abrasione ed all'impatto e non siano facilmente soggetti a fenomeni di corrosione. In altre parole, viene ricercata una particolare combinazione di parecchie caratteristiche. Generalmente i materiali maggiormente resistenti sono anche relativamente densi, presentano cioè indici di bontà piuttosto bassi; inoltre, spesso l'aumento di resistenza e di rigidezza di un materiale porta anche a diminuire la sua capacità di resistenza agli impatti.
La possibilità di combinare diverse proprietà in un unico materiale e di ampliarne il campo di impiego è stata ottenuta facendo uso dei cosiddetti materiali compositi. In generale un composito risulta caratterizzato da due o più fasi chimicamente distinte, insolubili e facilmente distinguibili in modo da sfruttare nel modo migliore le caratteristiche positive di tutti i costituenti.
Molti materiali compositi sono costituiti da due fasi: matrice e fase dispersa di rinforzo. Le proprietà finali di tali materiali dipendono strettamente dalle proprietà delle fasi costituenti, dalle loro quantità relative e dalla geometria delle fasi disperse, ossia forma, dimensione, distribuzione e orientamento degli elementi di rinforzo.
Una prima classificazione di questi materiali è legata alle dimensioni della fase di rinforzo; i compositi si possono quindi distinguere in: compositi particellari e fibro-rinforzati. In campo aeronautico e spaziale, i compositi rinforzati con fibre lunghe sono quelli che trovano il maggiore impiego; ciò è dovuto ad una molteplicità di motivi, tra i quali spiccano la possibilità di ottenere una forte integrazione strutturale e l'introduzione di processi automatici nella fase di produzione e riduzioni dei pesi strutturali.
Nel primo capitolo si fornisce un quadro generale sui compositi rinforzati con fibre; si vanno a caratterizzare i materiali compositi a matrice polimerica di più comune impiego aeronautico, soffermandosi sul confronto con i materiali metallici e sui requisiti di certificazione delle strutture aeronautiche realizzate in composito.
La progettazione di una struttura aeronautica richiede una continua valutazione della sua funzione strutturale in modo da determinare se i requisiti di progetto siano o meno stati soddisfatti. Le prestazioni previste in condizioni di esercizio devono essere verificate prima dell'entrata in servizio della struttura stessa; tale valutazione si ottiene grazie alle prove sperimentali full-scale, le quali permettono di assicurare e dimostrare l'integrità strutturale. Il capitolo 2 affronta in dettaglio la problematica delle prove strutturali di certificazione, descrive le metodologie impiegate per tale scopo e illustra quali siano le normative in materia attualmente in vigore.
Per l'ottenimento della certificazione, le normative richiedono, nell'analisi di una struttura in composito, l'impiego dei cosiddetti ammissibili di progetto. Gli ammissibili vengono ricavati grazie ad un'analisi statistica dei dati sperimentali ricavati da una campagna di prove di caratterizzazione del materiale impiegato. Si tratta di più di prove di laboratorio condotte su provini del medesimo materiale per l'ottenimento delle proprietà a livello di lamina. Questa campagna costituisce soltanto il gradino più basso del complesso di prove richieste per la certificazione. Ogni minimo cambiamento apportato alla composizione del materiale, alla stratificazione del laminato o alla procedura di fabbricazione vanifica tutte le prove svolte fino a quel momento e impone di iniziare da capo o di integrare la campagna di caratterizzazione.
Il presente lavoro di tesi, condotto presso il Dipartimento di Ingegneria Aerospaziale "Lucio Lazzarino" dell'Università di Pisa, si è incentrato sulla svolgimento di una parte consistente di prove sperimentali per la caratterizzazione di due distinti materiali compositi. Nel capitolo 3 si fornisce una descrizione delle attrezzature e della strumentazione impiegata per la realizzazione delle prove sopraddette.
Il capitolo 4 parla della conduzione delle prove di trazione e di taglio, delle metodologie per l'elaborazione dei dati secondo normativa e dell'analisi statistica effettuata sui dati sperimentali ottenuti
ProC global: a new automated screening assay for the evaluation of total function of the protein C system.
Protein C (PC) pathway represents a major physiologic inhibitory mechanism regulating the coagulation cascade. A new automated functional screening assay (ProC Global) for the evaluation of the PC-system was tested to define its ability to identify patients with known inherited defects such as factor V (FV) Leiden mutation and PC and protein S (PS) deficiency. A total of 249 patients who were symptomatic or asymptomatic for previous venous thromboembolism (VTE) were evaluated, 50 of whom had FV Leiden mutation, 36 had PC deficiency, and 34 had PS deficiency. One hundred healthy subjects were also tested, as well as 40 blood donors of both sexes in whom coagulation abnormalities were not found. Results of ProC Global test were expressed as normalized ratio (NR) and values below an established cut-off level were consistent with a positive test. ProC Global was positive in all 50 patients with the FV Leiden mutation (mean NR = 0.59; range, 0.37 to 0.69). ProC Global correctly identified 32 of 36 (89%) PC defects (mean NR = 0.63; range, 0.34 to 1.21) and 25 of 34 (73.5%) PS defects (mean NR = 0.76; range, 0.5 to 1.23). Overall, 92.5% of hereditary defects of the PC system considered in this study were identified by ProC Global test. ProC Global exhibited NR above cut-off level in all 40 blood donors without coagulation defects. ProC Global is a new automated screening test with some diagnostic potential in identifying patients with defects of the PC system. However, ProC Global in its current form cannot substitute the assay of each single component of this inhibitory system in the daily screening for thrombophilia
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The roles of Transient Receptor Potential (TRP) channels and aberrant calcium signalling in blood-retinal barrier dysfunction
The inner blood-retinal barrier (iBRB) protects the retinal vasculature from the peripheral circulation. Endothelial cells (ECs) are the core component of the iBRB; their close apposition and linkage via tight junctions limit the passage of fluids, proteins, and cells from the bloodstream to the parenchyma. Dysfunction of the iBRB is a hallmark of many retinal disorders. Vascular endothelial growth factor (VEGF) has been identified as the primary driver leading to a dysfunctional iBRB, thereby becoming the main target for therapy. However, a complete understanding of the molecular mechanisms underlying iBRB dysfunction is elusive and alternative therapeutic targets remain unexplored.
Calcium is a universal cellular messenger whose homeostasis is dysregulated in many pathological disorders. Among the extensive components of the cellular calcium signalling toolkit, cation-selective transient receptor potential (TRP) channels are broadly involved in cell physiology and disease and, therefore, are widely studied as possible targets for therapy. Albeit that TRP channels have been discovered in the photoreceptors of Drosophila and have been studied in the neuroretina, not much is known about their expression and function in the iBRB. Within this article, we discuss the structure and functions of the iBRB with a particular focus on calcium signalling in retinal ECs and highlight the potential of TRP channels as new targets for retinal diseases
Development of a Cell-Based Immunodetection Assay for Simultaneous Screening of Antiviral Compounds Inhibiting Zika and Dengue Virus Replication:
Practical cell-based assays can accelerate anti-Zika (ZIKV) and anti-dengue (DENV) virus drug discovery. We developed an immunodetection assay (IA), using a pan-flaviviral monoclonal antibody recognizing a conserved envelope domain. The final protocol includes a direct virus yield reduction assay (YRA) carried out in the human Huh7 cell line, followed by transfer of the supernatant to a secondary Huh7 culture to characterize late antiviral effects. Sofosbuvir and ribavirin were used to validate the assay, while celgosivir was used to evaluate the ability to discriminate between early and late antiviral activity. In the direct YRA, at 100, 50, and 25 TCID50, sofosbuvir IC50 values were 5.0 ± 1.5, 2.7 ± 0.5, 2.5 ± 1.1 µM against ZIKV and 16.6 ± 2.8, 4.6 ± 1.4, 2.6 ± 2.2 µM against DENV; ribavirin IC50 values were 6.8 ± 4.0, 3.8 ± 0.6, 4.5 ± 1.4 µM against ZIKV and 17.3 ± 4.6, 7.6 ± 1.2, 4.1 ± 2.3 µM against DENV. Sofosbuvir and ribavirin IC50 values determined in the secondary YRA were reproducible and comparable with those obtained by direct YRA and plaque reduction assay (PRA). In agreement with the proposed mechanism of late action, celgosivir was active against DENV only in the secondary YRA (IC50 11.0 ± 1.0 µM) and in PRA (IC50 10.1 ± 1.1 µM). The assay format overcomes relevant limitations of the gold standard PRA, allowing concurrent analysis of candidate antiviral compounds against different viruses and providing preliminary information about early versus late antiviral activity
“VEGF induces human endothelial progenitor cells proliferations by eliciting oscillations in intracellular Ca2+ concentration”
Endothelial progenitor cells (EPCs) traffic from the bone marrow to the site of tissue regeneration and sustain neo-vascularization after acute vascular injury and upon the angiogenic switch in solid tumors. Therefore, they represent a suitable tool for cell-based therapy in regenerative medicine and provide a novel promising target in the fight against cancer. The main stimulus responsible for EPC egression from the bone marrow and engraftment within neovessels is vascular endothelial growth factor (VEGF). Intracellular Ca2+ signals regulate numerous endothelial functions, such as proliferation, migration, and differentiation, and underpin VEGF effect on mature endothelium. We have recently shown that EPC growth is governed by a store-dependent Ca2+ entry (SOCE) pathway on the plasma membrane, which is activated by depletion of the inositol-1,4,5-trisphosphate (InsP3)-sensitive Ca2+ pools1. The present study aimed at investigating the nature and the role of VEGF-elicited Ca2+ signals in EPCs. All the putative SOCE mediators (i.e. TRPC1, TRPC4, Orai1 and Stim1) were present in EPCs. VEGF induced long lasting Ca2+ oscillations, however, removal of external Ca2+ (0Ca2+) and SOCE inhibition with BTP-2 reduced the number of Ca2+ spikes. Blockade of phospholipase C-? (PLC-?) with U73122 and emptying the InsP3-sensitive Ca2+ pools with cyclopiazonic acid (CPA) prevented the Ca2+ response to VEGF. Accordingly, the Ca2+ response to VEGF was inhibited by superfusing CPA during the ongoing oscillations. Notably, VEGF induced EPC was abrogated by SOCE inhibition with BTP-2. Similarly, VEGF promoted NF-kB translocation into the nucleus in a BTP-2-sensitive manner. Thus, VEGF causes an initial InsP3-dependent Ca2+ discharge followed by SOCE-mediated Ca2+ entry in cEPCs. SOCE, in turn, controls store refilling and induces cell proliferation by recruiting NF-kB
Phenotypic and functional characterization of endothelial progenitor cells isolated from peripheral blood of renal cell carcinoma patients
Endothelial progenitor cells (EPCs) are mobilized from either bone marrow or
arterial walls to restore blood perfusion to ischemic organs and establish the vascular
network within growing tumors [1]. The Ca2+ machinery plays a key role in EPC
activation and might serve a molecular target for novel therapies of highly angiogenic
tumors, such as renal cell carcinoma (RCC) [1]. The Ca2+ toolkit is remodelled in
EPCs isolated from RCC patients (RCC-EPCs) as respect to healthy donors [2]. The
present study was undertaken to evaluate for the first time the functional properties
of EPCs isolated from tumor patients by focusing on RCC-EPCs. We extended our
analysis at microscopic level by monitoring the sub-cellular structure of RCC-EPCs
relative to their Ca2+ signalling fingerprint. Our results showed a striking functional
and ultrastructural difference between RCC-EPCs and their normal counterparts,
which might be the basis for designing novel, more specific anti-angiogenic treatments
External quality assessment of HIV-1 DNA quantification assays used in the clinical setting in Italy
none18no: Total cell-associated HIV-1 DNA is a surrogate marker of the HIV-1 reservoir, however, certified systems for its quantification are not available. The Italian HIV DNA Network was launched to validate HIV-1 DNA quantification methods in use at University and Hospital labs. A quality control panel including HIV-1 DNA standards, reconstructed blood samples (RBSs) and DNA from different HIV-1 subtypes was blindly tested by 12 participating labs by quantitative real-time PCR (n = 6), droplet digital PCR (n = 3) or both (n = 3). The median 95% hit rate was 4.6 (3.7-5.5) copies per test and linearity in the tested range was excellent (R2 = 1.000 [1.000-1.000]). The median values obtained across labs were 3,370 (2,287-4,245), 445 (299-498), 59 (40-81) and 7 (6-11) HIV-1 DNA copies, for the 3,584, 448, 56 and 7-copy standards, respectively. With RBSs, measured values were within twofold with respect to the median in two thirds of cases. HIV-1 subtypes were missed (CRF01_AE by 3 labs) or underestimated by > 1 log (subtypes A, C, D, F by one lab; CRF01_AE by one lab; CRF02_AG by one lab). The overall performance was excellent with HIV-1 DNA standards, however detection of different HIV-1 subtypes must be improved.openVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, MaurizioVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, Maurizi
Pola Asuh Sebagai Prediktor Kontrol Diri
Each parents have their own way to raise their chidren, which is affecting on how each individual’s self control differs. The present research adresses this central assumption to know the correlation between parenting and individual’s self-control. There are 108 participants in this research, they are college students at Faculty of Psychology, Muhammadiyah University of Surakarta. The sampling technique used in this research is disproportional stratified random sampling. We used quantitative method with help of self-control scale dan parenting-perception scale as measuring tools. The collected data was analized by product moment correlation method with SPSS 16 for windows. Based on the result of the analized data, it shows 0,446 correlation coefficient value with 0,000 sig. (p) value, which means there is a very significant positive correlation between parenting and self-control. As for parenting’s contribution on self-control, determination coefficient’s value shows 19,9%. It means that there are 80,1% other factors which predisposing individual’s self-control
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