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Phosphorylation and nitration of protein tyrosine residues are thought to play a role in signaling pathways at the nerve terminal and to affect functional properties of proteins involved in the synaptic vesicle (SV) exo-endocytotic cycle. We previously demonstrated that the tyrosine residues in the C-terminal domain of the SV protein Synaptophysin (SYP) are targets of peroxynitrite (PN). Here, we have characterized the association between SYP and c-src tyrosine kinase demonstrating that phosphorylation of Tyr(273) in the C-terminal domain of SYP is crucial in mediating SYP binding to and activation of c-src. SYP forms a complex with Dynamin I (DynI), a GTPase required for SV endocytosis, which may be regulated by tyrosine phosphorylation of SYP. We here report that, in rat brain synaptosomes treated with PN, the formation of SYP/DynI complex was impaired. Noteworthy, we found that DynI was also modified by PN. DynI tyrosine phosphorylation was down-regulated in a dose-dependent manner, while DynI tyrosine nitration increased. Using mass spectrometry analysis, we identified Tyr(354) as one nitration site in DynI. In addition, we tested DynI self-assembly and GTPase activity, which are enhanced by c-src-dependent tyrosine phosphorylation of DynI, and found that both were inhibited by PN. Our results suggest that the site-specific tyrosine residue modifications may modulate the association properties of SV proteins and serve as a regulator of DynI function via control of self-assembly, thus influencing the physiology of the exo-endocytotic cycle.

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BackgroundBoth pathogenic bacteria and viruses are frequently detected in the nasopharynx (NP) of children in the absence of acute respiratory infection (ARI) symptoms. The aim of this study was to estimate the aetiological fractions for ARI hospitalisation in children for respiratory syncytial virus (RSV) and influenza virus and to determine whether detection of specific respiratory pathogens on NP samples was associated with ARI hospitalisation.Methods349 children up to 5 years of age hospitalised for ARI (following a symptom-based case definition) and 306 hospital controls were prospectively enrolled in 16 centres across seven European Union countries between 2016 and 2019. Admission day NP swabs were analysed by multiplex PCR for 25 targets.ResultsRSV was the leading single cause of ARI hospitalisations, with an overall population attributable fraction (PAF) of 33.4% and high seasonality as well as preponderance in younger children. Detection of RSV on NP swabs was strongly associated with ARI hospitalisation (OR adjusted for age and season: 20.6, 95% CI: 9.4 to 45.3). Detection of three other viral pathogens showed strong associations with ARI hospitalisation: influenza viruses had an adjusted OR of 6.1 (95% CI: 2.5 to 14.9), parainfluenza viruses (PIVs) an adjusted OR of 4.6 (95% CI: 1.8 to 11.3) and metapneumoviruses an adjusted OR of 4.5 (95% CI: 1.3 to 16.1). Influenza viruses had a PAF of 7.9%, PIVs of 6.5% and metapneumoviruses of 3.0%. In contrast, most other pathogens were found in similar proportions in cases and controls, including Streptococcus pneumoniae, which was weakly associated with case status, and endemic coronaviruses.ConclusionRSV is the predominant cause of ARI hospitalisations in young children in Europe and its detection, as well as detection of influenza virus, PIV or metapneumovirus, on NP swabs can establish aetiology with high probability. PAFs for RSV and influenza virus are highly seasonal and age dependent.

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Cardiotoxicity as a result of cancer treatment is a novel and serious public health issue that has a significant impact on a cancer patient's management and outcome. The coexistence of cancer and cardiac disease in the same patient is more common because of aging population and improvements in the efficacy of antitumor agents. Left ventricular dysfunction is the most typical manifestation and can lead to heart failure. Left ventricular ejection fraction measurement by echocardiography and multigated radionuclide angiography is the most common diagnostic approach to detect cardiac damage, but it identifies a late manifestation of myocardial injury. Early non-invasive imaging techniques are needed for the diagnosis and monitoring of cardiotoxic effects. Although echocardiography and cardiac magnetic resonance are the most commonly used imaging techniques for cardiotoxicity assessment, greater attention is focused on new nuclear cardiologic techniques, which can identify high-risk patients in the early stage and visualize the pathophysiologic process at the tissue level before clinical manifestation. The aim of this review is to summarize the role of nuclear imaging techniques in the non-invasive detection of myocardial damage related to antineoplastic therapy at the reversible stage, focusing on the current role and future perspectives of nuclear imaging techniques and molecular radiotracers in detection and monitoring of cardiotoxicity.

Background Few data are available about temporal trends of antibiotic use in hospitalized children. The aim of the current study was to investigate the pattern and trends of antibiotic use over the years 2008–2016 in the largest children’s hospital in Italy. Methods Annual point prevalence surveys of antibiotic use were conducted by reviewing medical charts of 0–17 year-old children hospitalized for ≥48 h. Prevalence of antibiotic use was computed by year, type of ward and indication. Trends in prevalence over time were evaluated using the Cochrane-Armitage test. Possibile determinants of antibiotic use were assessed at univariate analysis and through a logistic regression model. Results Out of 3015 children, 1516 (50.3%) received antibiotics, 58.1% of which for medical/surgical prophylaxis. Prevalence of antibiotic use increased from 42.0% in 2008 to 56.2% in 2016 ( p = 0.001). The prevalence of patients receiving antibiotics for medical prophylaxis increased from 6.1% in 2008 to 24.2% in 2016 ( p < 0.001), whereas the prevalence of patients receiving antibiotics for surgical prophylaxis significantly decreased (from 13.7 to 11.8%; p = 0.04); no significant temporal trends were found in antibiotic use for treating infections. The administration of third-generation cephalosporins for surgical and medical prophylaxis significantly decreased over time, while the proportion of antibiotics prescribed to treat infections after microbiological investigations significantly increased. Year (ORadj: 1.8 in 2016 compared to 2008, p < 0.001), age (ORadj ≥1.5 in children ≥1 year, compared to infants ≤2 months, p < 0.001), length of stay (LOS) (OR adj : 1.4 in case of LOS between 8 and 30 days compared to LOS ≤ 7 days, p < 0.001), and type of ward (ORadj: ≥1.3 in intensive-care, surgical and medical-subspecialty units compared to medical units, p < 0.001) were significantly and independently associated with antibiotic use. Conclusions Comparing prevalence rates of antibiotic use among hospitals and over time should consider differences in patient characteristics, such as age, ward of hospitalization and length of stay. Over the years, we documented an improvement in the choice of antibiotics prescribed for medical and surgical prophylaxis. However, further efforts are needed to avoid antibiotic misuse for medical prophylaxis, and to reduce the empirical use of broad spectrum antibiotics. Electronic supplementary material The online version of this article (10.1186/s13052-019-0645-7) contains supplementary material, which is available to authorized users.

Quantification of antibiotic utilization is an essential component of antibiotic stewardship programs. In this multicentric study, we used different metrics to evaluate inpatient antibiotic use in children. The study objectives were to describe point prevalence of antibiotic use by indication and patient characteristics, to evaluate DOTs, LOTs and PDDs, and to compare PDDs to DDDs, which assume average maintenance dose per day in adults. All children hospitalized on the days of the study were included. Trained personnel collected demographic and clinical data from patients’ clinical records. We recorded information about antibiotics administered on the date of data collection, and in the previous 30 days of hospitalization. Of 810 patients, 380 (46.9%; CI 95%: 43.4–50.4) received one or more antibiotics; prevalence of use was 27.0% for prophylaxis (219/810), and 20.7% (168/810) for treatment. Overall, 587 drugs were issued to the 380 patients receiving antibiotics (1.5 antibiotic per patient). When considering treatments, DOT and LOT per 100 patient-days were 30.5 and 19.1, respectively, resulting in a DOT/LOT ratio of 1.6. PDDs increased with age and approached DDDs only in children aged ≥ 10 years; the ratio between PDDs estimated in children aged ≥ 10 years and in 0–11 month-old infants ranged from 2 for sulfamethoxazole and trimethoprim, to 25 for meropenem. Our results confirm that DOT, LOT and PDD are better alternatives to DDD in children.