1,209 research outputs found
Mast cells as effector cells of innate immunity and regulators of adaptive immunity
No full textMast cells are widely distributed in human organs and tissues and they are particularly abundant at major body interfaces with the external environment such as the skin, the lung and the gastrointestinal tract. Moreover, mast cells are located around blood vessels and are highly represented within central and peripheral lymphoid organs. The strategic distribution of mast cells closely reflects the primary role of these cells in providing first-line defense against environmental dangers, in regulating local and systemic inflammatory reactions and in shaping innate and adaptive immune responses. Human mast cells have pleiotropic and multivalent functions that make them highly versatile cells able to rapidly adapt responses to microenvironmental changes. They express a wide variety of surface receptors including immunoglobulin receptors, pathogen-associated molecular pattern receptors and danger signal receptors. The abundance of these receptors makes mast cells unique and effective surveillance cells able to detect promptly aggression by viral, bacterial and parasitic agents. In addition, mast cells express multiple receptors for cytokines and chemokines that confer them the capacity of being recruited and activated at sites of inflammation. Once activated by immunological or nonimmunological stimuli mast cells secrete a wide spectrum of preformed (early) and de novo synthesized (late) mediators. Preformed mediators are stored within granules and are rapidly released in the extracellular environment to provide a fast vascular response that promotes inflammation and local recruitment of other innate immunity cells such as neutrophils, eosinophils, basophils and monocyte/macrophages. Later on, delayed release of multiple cytokines and chemokines from mast cells further induce modulation of cells of adaptive immunity and regulates tissue injury and, eventually, resolution of inflammation. Finally, mast cells express several costimulatory and inhibitory surface molecules that can finely tune activities of T cells, B cells and regulatory cells by cognate interactions within lymphoid organs. The multivalent capacity to recognize and to react to internal and external dangers together with their ability to cross-talk with other immunocompetent cells make mast cells a unique effector cell of innate responses and a main bridge between innate and adaptive immunity
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
EPR Spectroscopy Coupled with Spin Trapping as an Alternative Tool to Assess and Compare the Oxidative Stability of Vegetable Oils for Cosmetics
No full textAntioxidants are the most popular active ingredients in anti-aging cosmetics as they can restore the physiological radical balance and counteract the photoaging process. Instead of adding pure compounds into the formulations, some “precious” vegetable oils could be used due to their content of tocopherols, phenols, vitamins, etc., constituting a powerful antioxidant unsaponifiable fraction. Here, electron paramagnetic resonance (EPR) spectroscopy coupled with spin trapping was proven to provide a valid method for evaluating the antioxidant properties and the oxidative resistance of vegetable oils which, following UV irradiation, produce highly reactive radical species although hardly detectable. Extra virgin olive oil, sweet almond oil, apricot kernel oil, and jojoba oil were then evaluated by using N-t-butyl-α-phenylnitrone as a spin trapper and testing different UV irradiation times followed by incubation for 5 to 180 min at 70 °C. The EPR spectra were manipulated to obtain quantitative information useful for comparing the different tested samples. As a result, the knowledge acquired via the EPR analyses demonstrated jojoba oil as the best of the four considered oils in terms of both starting antioxidant ability and oxidative stability overtime. The obtained results confirmed the usefulness of the EPR spin trapping technique for the main proposed purpose
Meta-Analysis of Multiple Sclerosis Microarray Data Reveals Dysregulation in RNA Splicing Regulatory Genes
No full textAbnormalities in RNA metabolism and alternative splicing (AS) are emerging as important players in complex disease phenotypes. In particular, accumulating evidence suggests the existence of pathogenic links between multiple sclerosis (MS) and altered AS, including functional studies showing that an imbalance in alternatively-spliced isoforms may contribute to disease etiology. Here, we tested whether the altered expression of AS-related genes represents a MS-specific signature. A comprehensive comparative analysis of gene expression profiles of publicly-available microarray datasets (190 MS cases, 182 controls), followed by gene-ontology enrichment analysis, highlighted a significant enrichment for differentially-expressed genes involved in RNA metabolism/AS. In detail, a total of 17 genes were found to be differentially expressed in MS in multiple datasets, with CELF1 being dysregulated in five out of seven studies. We confirmed CELF1 downregulation in MS (p = 0.0015) by real-time RT-PCRs on RNA extracted from blood cells of 30 cases and 30 controls. As a proof of concept, we experimentally verified the unbalance in alternatively-spliced isoforms in MS of the NFAT5 gene, a putative CELF1 target. In conclusion, for the first time we provide evidence of a consistent dysregulation of splicing-related genes in MS and we discuss its possible implications in modulating specific AS events in MS susceptibility genes
Risk Factors and Cofactors for Severe Anaphylaxis
No full textPurpose of review
Severe anaphylaxis is a generalized reaction in which cardiovascular and respiratory involvement lead to a fatal or near-fatal outcome. Triggers of severe anaphylaxis differ from one age group to another and are mostly represented by drugs and hymenoptera stings in adults and food in children. Several risk factors and cofactors can increase the odds of severe anaphylaxis by different and still undefined mechanisms.
Recent findings
Major risk factors for severe anaphylaxis include old age, male sex, and preexisting medical conditions such as mast cell disorders, cardiovascular diseases, and uncontrolled asthma. Antihypertensive drugs appear to increase the severity of anaphylaxis probably by impairing compensatory mechanism to support blood pressure during the reaction. Severe reactions are also associated with transient cofactors such as exercise following specific allergen exposure, treatment with nonsteroidal anti-inflammatory drugs, and alcohol consumption.
Summary
Identification of risk factors and potential concurrent cofactors for each individual patient is mandatory to prevent severe anaphylaxis. Risk stratification is crucial to develop personalized prevention strategies and action plans to avoid potentially life-threatening reactions
Flow mediated dilation shows impaired endothelial function in patients with mastocytosis
No full textMastocytosis is a rare disease characterized by clonal proliferation of mast cells in different organs. Clinical manifestations of mastocytosis are mostly due to the release of mediators from mast cells and, in many cases such as urticaria, flushing, angioedema and anaphylaxis, are expression of biological effects of mediators on endothelial cells. Chronic secretion of mediators in patients with mastocytosis may lead to alteration of endothelial function
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
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Open AccessArticle
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID
INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy
*
Author to whom correspondence should be addressed.
Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602
Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023
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Abstract
SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings
Correction to: Safety and Psychological Outcomes of Tandem t:Slim X2 Insulin Pump with Control-IQ Technology in Children, Adolescents, and Young Adults with Type 1 Diabetes: A Systematic Review
No full textThe second author name was incorrectly published as Giula Maria Smylie. The correct name is Giulia Marie Smylie. The original article has been corrected
Biomarkers for evaluation of mast cell and basophil activation
No full textMast cells and basophils play a pathogenetic role in allergic, inflammatory, and autoimmune disorders. These cells have different development, anatomical location and life span but share many similarities in mechanisms of activation and type of mediators. Mediators secreted by mast cells and basophils correlate with clinical severity in asthma, chronic urticaria, anaphylaxis, and other diseases. Therefore, effective biomarkers to measure mast cell and basophil activation in vivo could potentially have high diagnostic and prognostic values. An ideal biomarker should be specific for mast cells or basophils, easily and reproducibly detectable in blood or biological fluids and should be metabolically stable. Markers of mast cell and basophil include molecules secreted by stimulated cells and surface molecules expressed upon activation. Some markers, such as histamine and lipid mediators are common to mast cells and basophils whereas others, such as tryptase and other proteases, are relatively specific for mast cells. The best surface markers of activation expressed on mast cells and basophils are CD63 and CD203. While these mediators and surface molecules have been associated to a variety of diseases, none of them fulfills requirements for an optimal biomarker and search for better indicators of mast cell/basophil activation in vivo is ongoing
Scrivere senza anestesia. La chiarezza di Giulia Niccolai
No full textIl saggio colloca storicamente la narratrice e poetessa Giulia Niccolai nel canone del Novecento letterario italiano discutendone poetica e cifre stilistiche. L'ampia analisi proposta tocca tutte le opere dell'autrice evidenziandone i legami intertestuali, anche tra poesia e narrativa, e i progressivi sviluppi in un arco cronologico esteso, tra anni Sessanta e primi anni Duemila. Lo studio coglie anche l'importanza dei riferimenti alle arti visive, in particolare alla fotografia, che Giulia Niccolai ha praticato in prima persona negli anni della Neoavanguardia, e alla pittura americana.The essay places the narrator and poet Giulia Niccolai in the canonical twentieth century Italian literary discussing her poetics and stylistic figures. The wide analysis proposed touches all the works of the author highlighting the intertextual links, also between poetry and narrative, and the progressive developments in an extended chronological period, between the Sixties and early Twenties. The study also captures the importance of references to the visual arts, especially photography, which Giulia Niccolai has practiced in the years of the Neo-avant-garde, and to American painting
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