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208 result(s) for "Zucchetti, S."
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Multidimensional severity assessment in bronchiectasis: an analysis of seven European cohorts
IntroductionBronchiectasis is a multidimensional disease associated with substantial morbidity and mortality. Two disease-specific clinical prediction tools have been developed, the Bronchiectasis Severity Index (BSI) and the FACED score, both of which stratify patients into severity risk categories to predict the probability of mortality.MethodsWe aimed to compare the predictive utility of BSI and FACED in assessing clinically relevant disease outcomes across seven European cohorts independent of their original validation studies.ResultsThe combined cohorts totalled 1612. Pooled analysis showed that both scores had a good discriminatory predictive value for mortality (pooled area under the curve (AUC) 0.76, 95% CI 0.74 to 0.78 for both scores) with the BSI demonstrating a higher sensitivity (65% vs 28%) but lower specificity (70% vs 93%) compared with the FACED score. Calibration analysis suggested that the BSI performed consistently well across all cohorts, while FACED consistently overestimated mortality in ‘severe’ patients (pooled OR 0.33 (0.23 to 0.48), p<0.0001). The BSI accurately predicted hospitalisations (pooled AUC 0.82, 95% CI 0.78 to 0.84), exacerbations, quality of life (QoL) and respiratory symptoms across all risk categories. FACED had poor discrimination for hospital admissions (pooled AUC 0.65, 95% CI 0.63 to 0.67) with low sensitivity at 16% and did not consistently predict future risk of exacerbations, QoL or respiratory symptoms. No association was observed with FACED and 6 min walk distance (6MWD) or lung function decline.ConclusionThe BSI accurately predicts mortality, hospital admissions, exacerbations, QoL, respiratory symptoms, 6MWD and lung function decline in bronchiectasis, providing a clinically relevant evaluation of disease severity.
Optimizing the ITER NBI ion source by dedicated RF driver test stand
The experimental fusion reactor ITER will feature two (or three) heating neutral beam injectors (NBI) capable of delivering 33(or 50) MW of power into the plasma. A NBI consists of a plasma source for production of negative ions (extracted negative ion current up to 329 A/m 2 in H and 285 A/m 2 in D) then accelerated up to 1 MeV for one hour. The negative ion beam is neutralized, and the residual ions are electrostatically removed before injection. The beamline was designed for a beam divergence between 3 and 7 mrad. The ion source in ITER NBIs relies on RF-driven, Inductively-Coupled Plasmas (ICP), based on the prototypes developed at IPP Garching; RF-driven negative-ion beam sources have never been employed in fusion devices up to now. The recent results of SPIDER, the full size ITER NBI ion source operating at NBTF in Consorzio RFX, Padova, measure a beamlet divergence minimum of 12mrad and highlighted beam spatial non-uniformity. SPIDER results confirmed the experimental divergence found in smaller prototype sources, which is larger compared to filament-arc ion sources. Although prototype experiments have shown that the extracted current requirement can be achieved with minor design improvements, the beamlet divergence is expected to marginally achieve the design value of 7 mrad, which in multi-grid long accelerators results in unexpected heat loads over the accelerator grids. A contributor to the beam divergence is the energy/temperature of the extracted negative ions, so it is believed that plasma differences between the two source types play a role. Research is focused on the plasma parameters in the ion source. One RF driver, identical to the ones used in SPIDER, installed in a relatively small-scale experimental set-up, inherently more flexible than large devices, is starting operations devoted to the investigation of the properties of RF-generated plasmas, so as to contribute to the assessment of negative ion precursors, and of their relationship with the plasma parameters, particularly when enhancing plasma confinement. The scientific questions, that have arisen from the preliminary results of SPIDER, guided the design of the test stand, which are described in this contribution, together with the diagnostic systems and related simulation tools. The test stand, which shares with the larger experiment all the geometrical features and constraints, will allow technological developments and optimized engineering solutions related to the ICP design for the ITER NBIs.
Continuous pulse advances in the negative ion source NIO1
Consorzio RFX and INFN-LNL have designed, built and operated the compact radiofrequency negative ion source NIO1 (Negative Ion Optimization phase 1) with the aim of studying the production and acceleration of H- ions. In particular, NIO1 was designed to keep plasma generation and beam extraction continuously active for several hours. Since 2020 the production of negative ions at the plasma grid (the first grid of the acceleration system) has been enhanced by a Cs layer, deposited though active Cs evaporation in the source volume. For the negative ion sources applied to fusion neutral beam injectors, it is essential to keep the beam current and the fraction of co-extracted electrons stable for at least 1 h, against the consequences of Cs sputtering and redistribution operated by the plasma. The paper presents the latest results of the NIO1 source, in terms of caesiation process and beam performances during continuous (6{\\div}7 h) plasma pulses. Due to the small dimensions of the NIO1 source (20 x (diam.)10 cm), the Cs density in the volume is high (10^15 \\div 10^16 m^-3) and dominated by plasma-wall interaction. The maximum beam current density and minimum fraction of co-extracted electrons were respectively about 30 A/m^2 and 2. Similarly to what done in other negative ion sources, the plasma grid temperature in NIO1 was raised for the first time, up to 80 {\\deg}C, although this led to a minimal improvement of the beam current and to an increase of the co-extracted electron current.
The role and impact of polyethylene glycol on anaphylactic reactions to COVID-19 nano-vaccines
Polyethylene glycol, used as a stabilizer in nanomedicine formulations, has recently been indicated as the possible cause of the anaphylactic reactions against the COVID-19 mRNA-based vaccines, but the evidence supporting this is contradictory, and other factors might be involved.
HLA-independent T cell receptors for targeting tumors with low antigen density
Chimeric antigen receptors (CARs) are receptors for antigen that direct potent immune responses. Tumor escape associated with low target antigen expression is emerging as one potential limitation of their efficacy. Here we edit the TRAC locus in human peripheral blood T cells to engage cell-surface targets through their T cell receptor–CD3 complex reconfigured to utilize the same immunoglobulin heavy and light chains as a matched CAR. We demonstrate that these HLA-independent T cell receptors (HIT receptors) consistently afford high antigen sensitivity and mediate tumor recognition beyond what CD28-based CARs, the most sensitive design to date, can provide. We demonstrate that the functional persistence of HIT T cells can be augmented by constitutive coexpression of CD80 and 4-1BBL. Finally, we validate the increased antigen sensitivity afforded by HIT receptors in xenograft mouse models of B cell leukemia and acute myeloid leukemia, targeting CD19 and CD70, respectively. Overall, HIT receptors are well suited for targeting cell surface antigens of low abundance. HLA-independent T cell receptors, in which the heavy and light chains of a chimeric antigen receptor are incorporated into the endogenous T cell receptor locus, are more effective than CD28-based chimeric antigen receptors at targeting tumors with low antigen expression.
IRAP-dependent endosomal T cell receptor signalling is essential for T cell responses
T cell receptor (TCR) activation is modulated by mechanisms such as TCR endocytosis, which is thought to terminate TCR signalling. Here we show that, upon internalization, TCR continues to signal from a set of specialized endosomes that are crucial for T cell functions. Mechanistically, TCR ligation leads to clathrin-mediated internalization of the TCR-CD3 ζ complex, while maintaining CD3 ζ signalling, in endosomal vesicles that contain the insulin responsive aminopeptidase (IRAP) and the SNARE protein Syntaxin 6. Destabilization of this compartment through IRAP deletion enhances plasma membrane expression of the TCR-CD3 ζ complex, yet compromises overall CD3 ζ signalling; moreover, the integrity of this compartment is also crucial for T cell activation and survival after suboptimal TCR activation, as mice engineered with a T cell-specific deletion of IRAP fail to develop efficient polyclonal anti-tumour responses. Our results thus reveal a previously unappreciated function of IRAP-dependent endosomal TCR signalling in T cell activation. T cell receptors (TCR) are internalized when activated by their ligands. Here the authors show that the internalized TCRs are localized to endosomes expressing IRAP and Syntaxin 6 to maintain intracellular signalling capacity, whose importance is shown by the absence of efficient polyclonal anti-tumour response in mice with T-specific conditional deletion of IRAP.
Characterizing Non-Tuberculous Mycobacteria Infection in Bronchiectasis
Chronic airway infection is a key aspect of the pathogenesis of bronchiectasis. A growing interest has been raised on non-tuberculous mycobacteria (NTM) infection. We aimed at describing the clinical characteristics, diagnostic process, therapeutic options and outcomes of bronchiectasis patients with pulmonary NTM (pNTM) disease. This was a prospective, observational study enrolling 261 adult bronchiectasis patients during the stable state at the San Gerardo Hospital, Monza, Italy, from 2012 to 2015. Three groups were identified: pNTM disease; chronic P. aeruginosa infection; chronic infection due to bacteria other than P. aeruginosa. NTM were isolated in 32 (12%) patients, and among them, a diagnosis of pNTM disease was reached in 23 cases. When compared to chronic P. aeruginosa infection, patients with pNTM were more likely to have cylindrical bronchiectasis and a “tree-in-bud” pattern, a history of weight loss, a lower disease severity and a lower number of pulmonary exacerbations. Among pNTM patients who started treatment, 68% showed a radiological improvement, and 37% achieved culture conversion without recurrence, while 21% showed NTM isolation recurrence. NTM isolation seems to be a frequent event in bronchiectasis patients, and few parameters might help to suspect NTM infection. Treatment indications and monitoring still remain an important area for future research.
Preclinical Activity of Two Paclitaxel Nanoparticle Formulations After Intraperitoneal Administration in Ovarian Cancer Murine Xenografts
Epithelial ovarian cancer is associated with high mortality due to diagnosis at later stages associated with peritoneal involvement. Several trials have evaluated the effect of intraperitoneal treatment. In this preclinical study, we report the efficacy, pharmacokinetics and pharmacodynamics of intraperitoneal treatment with two approved nanomolecular formulations of paclitaxel (nab-PTX and mic-PTX) in a murine ovarian cancer xenograft model. IC50 was determined in vitro on three ovarian cancer cell lines (OVCAR-3, SK-OV-3 and SK-OV-3-Luc IP1). EOC xenografts were achieved using a modified subperitoneal implantation technique. Drug treatment was initiated 2 weeks after engraftment, and tumor volume and survival were assessed. Pharmacokinetics and drug distribution effects were assessed using UHPLC-MS/MS and MALDI imaging mass spectrometry, respectively. Pharmacodynamic effects were analyzed using immunohistochemistry and transmission electron microscopy using standard protocols. We demonstrated sub-micromolar IC concentrations for both formulations on three EOC cancer cell lines in vitro. Furthermore, IP administration of nab-PTX or mic-PTX lead to more than 2-fold longer survival compared to a control treatment of IP saline administration (30 days in controls, 66 days in nab-PTX treated animals, and 76 days in mic-PTX animals, respectively). We observed higher tissue uptake of drug following nab-PTX administration when compared to mic-PTX, with highest uptake after 4 hours post-treatment, and confirmed this lower uptake of mic-PTX using HPLC on digested tumor samples. Furthermore, apoptosis was not increased in tumor implants up to 24h post-treatment. Intraperitoneal administration of both nab-PTX and mic-PTX results in a significant anticancer efficacy and survival benefit in a mouse OC xenograft model.
Hyaluronic-Coated Albumin Nanoparticles for the Non-Invasive Delivery of Apatinib in Diabetic Retinopathy
Apatinib (Apa) is a novel anti-vascular endothelial growth factor with the potential to treat diabetic retinopathy (DR); a serious condition leading to visual impairment and blindness. DR treatment relies on invasive techniques associated with various complications. Investigating topical routes for Apa delivery to the posterior eye segment is thus promising but also challenging due to ocular barriers. Hence, the study objective was to develop Apa-loaded bovine serum albumin nanoparticles (Apa-BSA-NPs) coated with hyaluronic acid (HA); a natural polymer possessing unique mucoadhesive and viscoelastic features with the capacity to actively target CD44 positive retinal cells, for topical administration in DR. Apa-BSA-NPs were prepared by desolvation using glutaraldehyde for cross-linking. HA-coated BSA-NPs were also prepared and HA: NPs ratio optimized. Nanoparticles were characterized for colloidal properties, entrapment efficiency (EE%), in vitro drug release and mucoadhesive potential. In vitro cytotoxicity on rabbit corneal epithelial cells (RCE) was assessed using MTT assay, while efficacy was evaluated in vivo in a diabetic rat model by histopathological examination of the retina by light and transmission electron microscopy. Retinal accumulation of fluorescently labeled BSA-NP and HA-BSA-NP was assessed using confocal microscope scanning. Apa-HA-BSA-NPs prepared under optimal conditions showed size, PdI and zeta potential: 222.2±3.56 nm, 0.221±0.02 and -37.3±1.8 mV, respectively. High EE% (69±1%), biphasic sustained release profile with an initial burst effect and mucoadhesion was attained. No evidence of cytotoxicity was observed on RCE cells. In vivo histopathological studies on DR rat model revealed alleviated retinal micro- and ultrastructural changes in the topical HA-Apa-BSA-NP treated eyes with normal basement membrane and retinal thickness comparable to normal control and intravitreally injected nanoparticles. Improved retinal accumulation for HA-BSA-NP was also observed by confocal microscopy. Findings present HA-Apa-BSA-NPs as a platform for enhanced topical therapy of DR overcoming the devastating ocular complications of the intravitreal route.
Adaptive downregulation of Cl-/HCO3- exchange activity in rat hepatocytes under experimental obstructive cholestasis
In obstructive cholestasis, there is an integral adaptive response aimed to diminish the bile flow and minimize the injury of bile ducts caused by increased intraluminal pressure and harmful levels of bile salts and bilirrubin. Canalicular bicarbonate secretion, driven by the anion exchanger 2 (AE2), is an influential determinant of the canalicular bile salt-independent bile flow. In this work, we ascertained whether AE2 expression and/or activity is reduced in hepatocytes from rats with common bile duct ligation (BDL), as part of the adaptive response to cholestasis. After 4 days of BDL, we found that neither AE2 mRNA expression (measured by quantitative real-time PCR) nor total levels of AE2 protein (assessed by western blot) were modified in freshly isolated hepatocytes. However, BDL led to a decrease in the expression of AE2 protein in plasma membrane fraction as compared with SHAM control. Additionally, AE2 activity (JOH-, mmol/L/min), measured in primary cultured hepatocytes from BDL and SHAM rats, was decreased in the BDL group versus the control group (1.9 ± 0.3 vs. 3.1 ± 0.2, p<0.005). cAMP-stimulated AE2 activity, however, was not different between SHAM and BDL groups (3.7 ± 0.3 vs. 3.5 ± 0.3), suggesting that cAMP stimulated insertion into the canalicular membrane of AE2-containing intracellular vesicles, that had remained abnormally internalized after BDL. In conclusion, our results point to the existence of a novel adaptive mechanism in cholestasis aimed to reduce biliary pressure, in which AE2 internalization in hepatocytes might result in decreased canalicular HCO3- output and decreased bile flow.