Valutazione degli effetti modulatori di tre specie di Echinacea sulla generazione, maturazione e attivita' funzionale delle cellule dendritiche umane

Introduzione. L’Echinacea è una pianta erbacea perenne originaria del Nord America, ma da molto tempo coltivata anche in Europa. Esistono dieci specie appartenenti al genere, di cui solo tre presentano proprietà medicinali: Echinacea angustifolia, Echinacea pallida, Echinacea purpurea. Ad oggi formulazioni costituite da estratti di Echinacea sono state impiegate comunemente in virtù della loro attività immunostimolante, antinfiammatoria, antivirale e antiossidante, anche se il meccanismo d’azione dei principi attivi di tali componenti non è stato ancora sufficientemente investigato. Pertanto questo studio si è proposto di approfondire il meccanismo di azione tramite cui i fitoestratti di Echinacea svolgono l’attività immunostimolante; in particolare è stato indagato l’effetto di tali composti sulla generazione, maturazione e attività funzionale delle cellule dendritiche (DC). Le DC sono le più importanti cellule presentanti l’antigene: controllano sia l’inizio che il mantenimento delle risposte immuni adattative e l’induzione di tolleranza. Materiali e Metodi. Le DC sono state generate a partire da monociti CD14+ circolanti, ottenuti da cellule mononucleate provenienti da buffy coat di donatori sani mediante separazione immunomagnetica. I monociti CD14+ così ottenuti sono stati coltivati in terreno RPMI 1640 addizionato di siero fetale bovino, L-glutammina, streptomicina e penicillina, e supplementato con fattori di crescita (GM-CSF e IL-4), in presenza o assenza di estratto di radice delle tre specie di Echinacea a concentrazioni comprese tra 3 e 300 &mu;g/mL. Al 6° giorno di coltura le cellule ottenute sono state indotte a maturare mediante aggiunta di LPS per ulteriori 24 ore; al 7° giorno le cellule mature sono state sottoposte ad analisi morfologica (tramite allestimento di citocentrifugati e colorazione May-Grunwald Giemsa) e fenotipica (mediante citometria a flusso). Marcatori utilizzati sono l’antigene CD14, espresso dai monociti e perso durante il processo di generazione delle DC, le molecole costimolatorie CD40 e CD80, l’antigene HLA di classe II (HLA-DR) e l’antigene CD83 espresso dalle DC mature. Studi funzionali delle DC, in presenza di E. purpurea, hanno compreso l’analisi citofluorimetrica dell’attività endocitotica mediata dal recettore per il mannosio, utilizzando come antigene il destrano FITC-coniugato, ed il dosaggio con metodo immunoenzimatico delle citochine (IL-6, IL-1, IL-10, IL-12, TGF-&beta;, TNF-&alpha;) rilasciate nei surnatanti delle colture di DC. Risultati. I fitoestratti non compromettono la generazione delle DC a partire dai monociti (perdita di espressione dell’antigene CD14), mentre ne ostacolano la maturazione, come mostrato dalla ridotta espressione dell’antigene CD83 ( 83%). In presenza di Echinacea, inoltre, è stata osservata una ridotta espressione (sia come percentuale che come intensità media di fluorescenza) delle molecole di superficie CD80 ( 84% e > 86%); per quanto riguarda l’antigene CD40 è stata osservata una riduzione di espressione della sola intensità media di fluorescenza (< 500, nel controllo: 700). Non sono state riscontrate differenze significative relative al fenotipo cellulare tra gli estratti provenienti dalle tre specie in analisi. Dall’analisi dell’endocitosi, in presenza dell’E. purpurea alla concentrazione di 100 &mu;g/mL, sono emersi risultati contrastanti, in quanto alcuni esperimenti hanno mostrato un incremento dell’attività endocitotica mentre altri una riduzione, sebbene nessun dato sia statisticamente significativo. Sono quindi necessari ulteriori esperimenti. Conclusioni. Questi risultati preliminari dimostrano un’attività immunomodulatoria dell’Echinacea sulle DC, con effetti sovrapponibili per tutte e tre le specie. L’attività funzionale delle suddette cellule sarà oggetto di ulteriori approfondimenti

Gain variations as induced by the diffuse night sky background: the ASTRI-Horn experience

ASTRI-Horn is the prototype of the nine telescopes that form the ASTRI Mini-Array, under construction at the Teide Observatory in Spain, devoted to observe the sky above 10 TeV. It adopts an innovative optical design based on a dual-mirror Schwarzschild-Couder configuration, and the camera, composed by a matrix of monolithic multipixel silicon photomultipliers (SiPMs) is managed by ad-hoc tailored front-end electronics based on a peak-detector operation mode. During the Crab Nebula campaign in 2018-2019, ASTRI-Horn was affected by gain variations induced by high levels of night sky background. This paper reports the work performed to detect and quantify the effects of these gain variations in shower images. The analysis requested the use of simultaneous observations of the night sky background flux in the wavelength band 300-650 nm performed with the auxiliary instrument UVscope, a calibrated multi-anode photomultiplier working in single counting mode. As results, a maximum gain reduction of 15% was obtained, in agreement with the value previously computed from the variance of the background level in each image. This ASTRI-Horn gain reduction was caused by current limitation of the voltage supply. The analysis presented in this paper provides a method to evaluate possible variations in the nominal response of SiPMs when scientific observations are performed in the presence of high night sky background as in dark or gray conditions.Comment: 14 pages, 8 figures -- Submitted to Journal of Instrumentation (JINST) peer review on 10 November 202

Heptavalent Pneumococcal Conjugate Vaccine: growing knowledge and its implications for Italy

Introductive note A wide literature on Streptococcus Pneumoniae (Pn) infections is available, largely published in the recent years, after the introduction of the heptavalent conjugate vaccine in US and in Europe. This review is based on the most up-to-date scientific articles about this pathogen

Muon calibration of the ASTRI-Horn telescope: preliminary results

Astri-Horn is a Small-Sized Telescope (SST) for very-high energy gamma-ray astronomy installed in Italy at the INAF "M.C. Fracastoro" observing station (Mt. Etna, Sicily). The ASTRI-Horn telescope is characterized by a dual-mirror optical system and a curved focal surface covered by SiPM sensors managed by a innovative fast front-end electronics. Dedicated studies were performed to verify the feasibility of the calibration through muons on the relatively small size of the primary mirror (~4 m diameter), as in the case of larger Cherenkov telescopes. A number of tests were performed using simulations of the atmospheric showers with the CORSIKA package and of the telescope response with a dedicated simulator. In this contribution we present a preliminary analysis of muon events detected by ASTRI-Horn during the regular scientific data taking performed in December 2018 and March 2019. These muon events validate the results obtained with the simulations and definitively confirm the feasibility of calibrating the ASTRI-Horn SST telescope with muons.Comment: Proceedings of the 36th International Cosmic Ray Conference, Madison, Wisconsin, USA, 24 July-1 August 201

Galactic observatory science with the ASTRI Mini-Array at the Observatorio del Teide

The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array will be composed of nine imaging atmospheric Cherenkov telescopes at the Observatorio del Teide site. The array will be best suited for astrophysical observations in the 0.3-200 TeV range with an angular resolution of few arc-minutes and an energy resolution of 10-15%. A core-science programme in the first four years will be devoted to a limited number of key targets, addressing the most important open scientific questions in the very-high energy domain. At the same time, thanks to a wide field of view of about 10 degrees, ASTRI Mini-Array will observe many additional field sources, which will constitute the basis for the long-term observatory programme that will eventually cover all the accessible sky. In this paper, we review different astrophysical Galactic environments, e.g. pulsar wind nebulae, supernova remnants, and gamma -ray binaries, and show the results from a set of ASTRI Mini-Array simulations of some of these field sources made to highlight the expected performance of the array (even at large offset angles) and the important additional observatory science that will complement the core-science program

Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project

In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory

The Software Architecture and development approach for the ASTRI Mini-Array gamma-ray air-Cherenkov experiment at the Observatorio del Teide

The ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF) and devoted to the imaging of atmospheric Cherenkov light for very-high gamma-ray astronomy. The project is deploying an array of 9 telescopes sensitive above 1 TeV. In this contribution, we present the architecture of the software that covers the entire life cycle of the observatory, from scheduling to remote operations and data dissemination. The high-speed networking connection available between the observatory site, at the Canary Islands, and the Data Center in Rome allows for ready data availability for stereo triggering and data processing

ASTRI Mini-Array core science at the Observatorio del Teide

The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few tera-electronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics

La sindrome gastroenterica del coniglio da compagnia

Riassunto Con il termine sindrome gastroenterica del coniglio da compagnia si intende un quadro patologico molto variegato di segni clinici, sintomi e situazioni patologiche che coinvolgono l’apparato gastroenterico di questa specie e portano ad anoressia, dolorabilità addominale, gonfiore addominale, stipsi e, se non trattati, a morte. Il presente studio ha visto l’analisi di 27 casi di conigli che si sono presentati in condizioni di sindrome gastroenterica e dei quali è stata studiata l’anamnesi nel tentativo di stabilire se esistano o meno dei fattori comuni potenzialmente predisponenti alla patologia. È emersa la possibilità che temperatura ambientale ed alimentazione possano giocare un ruolo importante in questo senso. Questa considerazione può essere uno spunto per ulteriori approfondimenti visto che, dati i pochi soggetti considerati, resta per ora solo un’ipotesi. Summary The Rabbit Gastrointestinal Syndrome (RGIS) is a complex of clinical signs, symptoms and concurrent pathologic conditions affecting the digestive apparatus of this species. It causes anorexia, abdominal pain, abdominal dilation, constipation and, if not treated, death. This study has taken into consideration 27 cases of rabbits which have been taken to the vet with RGIS: an accurate anamnesis has been made in order to establish the existence of commonalities that can predispose to the disease. The research has brought to light the possibility that environmental temperature and diet play an important role in the pathogenesis. This assumption can represent a starting point for further investigations since, because of the few cases treated, it remains an hypothesis