Epidemiologia delle infezioni da amebe a vita libera

Le amebe a vita libera (spesso conosciute come Free-Living Amoebae, FLA) sono protozoi presenti in tutte le matrici ambientali a diffusione cosmopolita. L’etichetta di organismi “a vita libera” deriva dal fatto che il loro serbatoio è l’ambiente acquatico naturale, e quello realizzato dall’uomo è un habitat secondario favorevole. Sono protozoi unicellulari che possono vivere all’interno di un ospite in condizioni di parassitismo facoltativo o avere un’esistenza autonoma. Per tale proprietà sono anche definite amebe anfizoiche. In particolare, anche se in realtà è Acanthamoeba spp. il protozoo più frequentemente rilevabile nell’ambiente, amebe a vita libera sono state isolate da suolo, sedimenti, polveri, aria, acque naturali e reflue, dolci, marine, termali, e sono state anche rilevate in acque confezionate, potabilizzate e sottoposte a trattamenti di disinfezione (acque destinate al consumo umano e di piscina) e in biofilm. Numerose specie di amebe a vita libera sono state segnalate in torri di raffreddamento, impianti di climatizzazione, deumidificatori, unità di dialisi, riuniti dentistici, apparecchi per il trattamento domestico dell’acqua e su lenti a contatto. Individuate nell’uomo e in animali a sangue caldo e freddo, in soggetti malati sono state isolate da ferite, dalla cornea, dai polmoni e dal sistema nervoso centrale, anche se la loro presenza è stata dimostrata anche in individui sani. La loro distribuzione e diversità nell’ambiente sono fortemente influenzate da temperatura, umidità, pH, disponibilità di nutrienti e appare chiara l’esistenza di un loro andamento stagionale. In condizioni ambientali ostili le amebe producono cisti che excistano solo in condizioni favorevoli liberando trofozoiti. Sopravvivenza e moltiplicazione sono anche associate sia alla presenza di batteri, soprattutto Gram-negativi, sia alla concentrazione degli stessi batteri. Infatti, con rapporti di concentrazione ameba: batteri di 1:104, lo sviluppo dei protozoi è inibito. Per il basso numero di infezioni riscontrate, le amebe non hanno mai rappresentato un argomento sanitario di interesse prioritario, anche se la mancanza di farmaci efficaci e l’esito quasi sempre fatale delle malattie indotte da alcune specie, le hanno sempre rese oggetto di interesse e di studio. Negli ultimi decenni tuttavia, un’attenzione particolare è stata loro rivolta per il ruolo che rivestono come veicolo di trasmissione di microrganismi patogeni presenti nell’ambiente idrico. Infatti, circa un quarto degli isolati di origine ambientale, clinica o derivanti da lenti a contatto contengono microrganismi endosimbionti, definiti Amoeba-Resistant Microorganisms (ARM), microrganismi resistenti alle amebe, che sono in grado di mantenere la loro vitalità a livello intracellulare. Le amebe fungono così da riserva per altri microrganismi, proteggendoli da fattori ambientali ostili e fornendo condizioni favorevoli alla loro replicazione. Per questa circostanza, nel 2017, presso la III Sezione del Consiglio Superiore di Sanità, presieduta dalla Prof.ssa Anna Teresa Palamara, e coordinata dalla Dott.ssa Anna Gaspardone, è stato istituito un Gruppo di Lavoro il cui compito è stato quello sia di approfondire gli aspetti sanitari associati alle amebe a vita libera rilevabili nelle acque, sia di valutare la rilevanza del problema in un’ottica di salvaguardia della salute. A seguito delle attività del Gruppo di lavoro è stato quindi predisposto il documento condiviso e di seguito presentato che produce informazioni sulle caratteristiche tassonomiche ed ecologiche di questi organismi, sulle loro possibili implicazioni di carattere sanitario, sul loro adattamento nelle reti di distribuzione idrica e sulle dinamiche di interazione con gli altri microrganismi. Inoltre, il volume fornisce un indirizzo metodologico univoco e specifiche raccomandazioni per minimizzare il rischio associato alla presenza di amebe nell’ambiente idrico, nonché, in Appendice, metodi analitici colturali e molecolari per la ricerca di questi organismi nelle acque

Validation of a questionnaire about knowledge and perception of biological risk among biomedical students of Sapienza University of Rome

Background and aim. Healthcare workers and Biomedical students are continuously exposed to biological risk in their clinical practice. The objective of this study was to evaluate the validity and reliability of an Italian questionnaire on the knowledge and perception of biological risk in Biomedical students at the beginning of their professional training. Material and methods.An electronic questionnaire was administered to students attending the second semester of the first year of Biomedical Courses at Sapienza University of Rome. The questionnaire consists of 40 questions divided into five sections collecting sociodemographic data, health status and level of knowledge and perception of biological risk. The statistical analysis was performed with Statistical Package for Social Sciences (SPSS) version 25. Results. A total of 309 individuals answered the online questionnaire, with a response rate of 83.5%. The analysis of internal consistency was performed by two dichotomous variables that measured the knowledge level on hygiene behaviour and gloves use. The analysis showed a standardized Cronbach’s alpha equal to 0.765, corresponding to a good reliability. A better reliability was found out among physiotherapy and medical students, with a Cronbach’s alpha equal to 0.944 and 0.881, respectively. Regarding vaccines, 97.7% of the sample was given a Hepatitis B vaccination and 98.7% of students consider vaccinations essential for healthcare workers. Conclusion. Results of Cronbach’s alpha showed a good reliability of the questionnaire. First-year Biomedical students may be exposed to occupational biological risk mainly because of their inexperience. A training educational path should be implemented in order to acquire competences, knowledge, attitudes and practical skills, correct behaviors and a personal and professional responsibility

La metafisica del dolore

Il dolore pone le sue radici nella notte dei tempi. Da sempre è stato oggetto d’interesse per il genere umano, suscitando timore e superstizione nell’antichità, studio e analisi nei tempi successivi. Ricerche accurate effettuate nei secoli sull’argomento hanno consentito solo oggi di poterlo comprendere e controllare nel migliore dei modi. Per anni, la difficoltà maggiore è stata quella di voler descrivere, in poche parole, una condizione che aveva risvolti psicologici, fisiopatologici, emotivi ed affettivi. C'è una disciplina che studia l'essere in quanto essere e le proprietà che gli sono inerenti per la sua stessa natura e non si identifica con nessuna delle cosiddette scienze particolari, giacché nessuna delle altre ha come suo oggetto d'indagine universale l'essere in quanto essere. Ciascuna di esse, infatti, ritaglia per proprio conto una qualche parte dell'essere e ne studia gli attributi, come fanno, ad esempio, le scienze matematiche. Solo la metafisica può farlo, visto che si tratta di una branca della Filosofia. La maggior parte di coloro che per primi filosofarono, pensarono che principi di tutte le cose fossero solo quelli materiali. Non a caso, essi affermano che ciò di cui tutti gli esseri sono costituiti (ciò da cui derivano originariamente e in cui si risolvono da ultimo) è elemento ed è principio degli esseri, in quanto è una realtà che permane identica pur nel trasmutarsi delle sue affezioni

Non-dimensional probabilistic analysis of seismic pounding between flexible structures and rigid boundaries

Pounding between adjacent structures subjected to earthquake actions can cause significant damage. Due to the many uncertainties inherent to the seismic input and the impact phenomenon, a probabilistic assessment of the occurrence of seismic pounding and of its consequences on the structural performance is necessary. This work analyzes the problem of pounding by considering a single-degree-of-freedom benchmark system surrounded by rigid boundaries and subjected to a stochastic earthquake input. Although simplified, the model is representative of several realistic configurations, such as base-isolated systems surrounded by moat walls or bridge decks near the bridge abutments. The problem is cast in non-dimensional form and a parametric study is carried out to evaluate the influence of the identified non-dimensional input parameters on the statistics of the response. A probabilistic demand model is developed for the impact forces via non-linear regression, with the demand expressed as a function of the identified non-dimensional parameters. This model provides an estimate of median pounding force and of its dispersion given the seismic intensity of the input. Finally, global sensitivity analysis is used to rank the model parameters in terms of their influence on the system performance

Successful salvage therapy with Daptomycin for osteomyelitis caused by methicillin-resistant Staphylococcus aureus in a renal transplant recipient with Fabry-Anderson disease

Daptomycin is licensed in adults for the management of Staphylococcus aureus methicillin-resistant infections, including bone and skin complicated infections. We describe for the first time its use in a renal transplant recipient for Fabry-Anderson Disease with right heel osteomyelitis. The patient was unresponsive to first-line Teicoplanin and second-line Tigecycline, whereas he was successfully treated with third-line Daptomycin monotherapy at 4 mg/Kg/qd for 4 weeks. Local debridement was performed in advance of each line of treatment

Knowledge and perception about climate change among healthcare professionals and students: A cross-sectional study

Aim: The aim of this study was to assess knowledge on Climate Change (CC) and related consequences among students and professionals of healthcare setting. Methods: A cross-sectional study involving 364 people was conducted. The survey was performed at Sapienza University (Rome) using questionnaire previously developed and validated by the same research group. Results: Findings indicate awareness about CC and its effects and correct identification of practices that could help to mitigate its repercussions. The majority of the participants believed that CC had an impact on the health of humans (96.7%), animals (99.5%) and on the environment (99.7%). Results from the multivariate analysis regarding overall knowledge, show an increased odd in professionals (OR=2.08; 95%CI=1.02-4.26), individuals from the North (OR=3.34; 95%CI=1.37-8.15) and from the Center (OR=2.07; 95%CI=1.17-3.66). Regarding factors able to modify Earth's climate, correct answer had higher odds of being chosen by professionals (OR=2.83; 95%CI=1.41–5.70), and from individuals from South/Islands than by the ones from the Center (OR=0.65; 95%CI=0.40-1.06). The main sources of information resulted to be TV and school/university. Conclusions: These new evidences could guide policymakers on increasing the awareness of the population about this fundamental subject. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Knowledge and perception about climate change among healthcare professionals and students: A cross-sectional study

Aim: The aim of this study was to assess knowledge on Climate Change (CC) and related consequences among students and professionals of healthcare setting. Methods: A cross-sectional study involving 364 people was conducted. The survey was performed at Sapienza University (Rome) using questionnaire previously developed and validated by the same research group. Results: Findings indicate awareness about CC and its effects and correct identification of practices that could help to mitigate its repercussions. The majority of the participants believed that CC had an impact on the health of humans (96.7%), animals (99.5%) and on the environment (99.7%). Results from the multivariate analysis regarding overall knowledge, show an increased odd in professionals (OR=2.08; 95%CI=1.02-4.26), individuals from the North (OR=3.34; 95%CI=1.37-8.15) and from the Center (OR=2.07; 95%CI=1.17-3.66). Regarding factors able to modify Earth's climate, correct answer had higher odds of being chosen by professionals (OR=2.83; 95%CI=1.41–5.70), and from individuals from South/Islands than by the ones from the Center (OR=0.65; 95%CI=0.40-1.06). The main sources of information resulted to be TV and school/university. Conclusions: These new evidences could guide policymakers on increasing the awareness of the population about this fundamental subject. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.   Author contributions: Conceptualization, G.L.T. and A.D.C..; Methodology, G.L.T. and A.M..; Formal Analysis, A.D.P.B., C.S., R.A.C., D.B.; Investigation, A.D.P.B., C.S., R.A.C., D.B.; Data Curation, A.D.P.B., C.S.; Writing – Original Draft Preparation, R.A.C., D.B.; Writing – Review & Editing, R.A.C., D.B., A.M..; Supervision, G.L.T..; Project Administration, G.L.T.   Conflicts of interest: None declare

Deep learning image reconstruction algorithm. impact on image quality in coronary computed tomography angiography

PurposeTo perform a comprehensive intraindividual objective and subjective image quality evaluation of coronary CT angiography (CCTA) reconstructed with deep learning image reconstruction (DLIR) and to assess correlation with routinely applied hybrid iterative reconstruction algorithm (ASiR-V).Material and methodsFifty-one patients (29 males) undergoing clinically indicated CCTA from April to December 2021 were prospectively enrolled. Fourteen datasets were reconstructed for each patient: three DLIR strength levels (DLIR_L, DLIR_M, and DLIR_H), ASiR-V from 10% to 100% in 10%-increment, and filtered back-projection (FBP). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) determined objective image quality. Subjective image quality was assessed with a 4-point Likert scale. Concordance between reconstruction algorithms was assessed by Pearson correlation coefficient.ResultsDLIR algorithm did not impact vascular attenuation (P >= 0.374). DLIR_H showed the lowest noise, comparable with ASiR-V 100% (P = 1) and significantly lower than other reconstructions (P <= 0.021).DLIR_H achieved the highest objective quality, with SNR and CNR comparable to ASiR-V 100% (P = 0.139 and 0.075, respectively). DLIR_M obtained comparable objective image quality with ASiR-V 80% and 90% (P >= 0.281), while achieved the highest subjective image quality (4, IQR: 4-4; P <= 0.001). DLIR and ASiR-V datasets returned a very strong correlation in the assessment of CAD (r = 0.874, P = 0.001).ConclusionDLIR_M significantly improves CCTA image quality and has very strong correlation with routinely applied ASiR-V 50% dataset in the diagnosis of CAD

A low-mass planet candidate orbiting Proxima Centauri at a distance of 1.5 AU

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).Our nearest neighbor, Proxima Centauri, hosts a temperate terrestrial planet. We detected in radial velocities evidence of a possible second planet with minimum mass m c sin i c = 5.8 ± 1.9 M ⊕ and orbital period P c = 5.21 - 0.22 + 0.26 years. The analysis of photometric data and spectro-scopic activity diagnostics does not explain the signal in terms of a stellar activity cycle, but follow-up is required in the coming years for confirming its planetary origin. We show that the existence of the planet can be ascertained, and its true mass can be determined with high accuracy, by combining Gaia astrometry and radial velocities. Proxima c could become a prime target for follow-up and characterization with next-generation direct imaging instrumentation due to the large maximum angular separation of ~1 arc second from the parent star. The candidate planet represents a challenge for the models of super-Earth formation and evolution.Peer reviewedFinal Published versio

Effects of inhibition of the renin-angiotensin system on hypertension-induced target organ damage: clinical and experimental evidence.

The dysregulation of renin-angiotensin-system (RAS) plays a pivotal role in hypertension and in the development of the related target organ damage (TOD). The main goal of treating hypertension is represented by the long-term reduction of cardiovascular (CV) risk. RAS inhibition either by angiotensin converting enzyme (ACE)-inhibitors or by type 1 Angiotensin II receptors blockers (ARBs), reduce the incidence of CV events in hypertensive patients. Actually, ACE-inhibitors and ARBs have been demonstrated to be effective to prevent, or delay TOD like left ventricular hypertrophy, chronic kidney disease, and atherosclerosis. The beneficial effects of RAS blockers on clinical outcome of hypertensive patients are due to the key role of angiotensin II in the pathogenesis of TOD. In particular, Angiotensin II through an inflammatory-mediated mechanism plays a role in the initiation, progression and vulnerability of atherosclerotic plaque. In addition, Angiotensin II can be considered the hormonal transductor of the pressure overload in cardiac myocytes, and through an autocrine-paracrine mechanism plays a role in the development of left ventricular hypertrophy. Angiotensin II by modulating the redox status and the immune system participates to the development of chronic kidney disease. The RAS blocker should be considered the first therapeutic option in patients with hypertension, even if ACE-inhibitors and ARBs have different impact on CV prevention. ARBs seem to have greater neuro-protective effects, while ACE-inhibitors have greater cardio-protective action