200 research outputs found

    First Computation of Parasitic Fields in LHC Dipole Magnet Interconnects

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    The Large Hadron Collider (LHC), now under construction at CERN, will rely on about 1600 main superconducting dipole and quadrupole magnets and over 7400 superconducting corrector magnets distributed around the eight sectors of the machine. Each magnet type is powered by dedicated superconducting busbars running along the sectors and mounted on the iron yokes of the main dipole and quadruple magnets. In the numerous magnet interconnects, the busbars are not magnetically shielded from the beam pipes and produce parasitic fields that can affect beam optics. We review the 3-D models that have been developed with ROXIE to compute the parasitic fields and we discuss their potential impacts on machine performance

    Enteroviral Infections in the First Three Months of Life

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    Enteroviruses (EVs) are an important source of infection in the paediatric age, with most cases concerning the neonatal age and early infancy. Molecular epidemiology is crucial to understand the circulation of main serotypes in a specific area and period due to their extreme epidemiological variability. The diagnosis of EVs infection currently relies on the detection of EVs RNA in biological samples (usually cerebrospinal fluid and plasma, but also throat swabs and feces) through a poly-merase chain reaction assay. Although EVs infections usually have a benign course, they sometimes become life threatening, especially when symptoms develop in the first few days of life. Mortality is primarily associated with myocarditis, acute hepatitis, and multi-organ failure. Neurodevelopmental sequelae have been reported following severe infections with central nervous system involvement. Unfortunately, at present, the treatment of EVs infections is mainly supportive. The use of specific antiviral agents in severe neonatal infections has been reported in single cases or studies includ-ing few neonates. Therefore, further studies are needed to confirm the efficacy of these drugs in clinical practice

    From Bed to Bench and Back: TNF-α, IL-23/IL-17A, and JAK-Dependent Inflammation in the Pathogenesis of Psoriatic Synovitis

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    Psoriatic arthritis (PsA) is a chronic inflammatory immune-mediated disease with a burdensome impact on quality of life and substantial healthcare costs. To date, pharmacological interventions with different mechanisms of action, including conventional synthetic (cs), biological (b), and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs), have been proven efficacious, despite a relevant proportion of failures. The current approach in clinical practice and research is typically “predictive”: the expected response is based on stratification according to clinical, imaging, and laboratory data, with a “heuristic” approach based on “trial and error”. Several available therapeutic options target the TNF-α pathway, while others are directed against the IL-23/IL-17A axis. Janus kinase inhibitors (JAKis), instead, simultaneously block different pathways, endowing these drugs with a potentially “broad-spectrum” mechanism of action. It is not clear, however, whether targeting a specific pathway (e.g., TNF-α or the IL-23/IL-17 axis) could result in discordant effects over other approaches. In particular, in the case of “refractory to a treatment” patients, other pathways might be hyperactivated, with opposing, synergistic, or redundant biological significance. On the contrary, refractory states could be purely resistant to treatment as a whole. Since chronic synovitis is one of the primary targets of inflammation in PsA, synovial biomarkers could be useful in depicting specific biological characteristics of the inflammatory burden at the single-patient level, and despite not yet being implemented in clinical practice, these biomarkers might help in selecting the proper treatment. In this narrative review, we will provide an up-to-date overview of the knowledge in the field of psoriatic synovitis regarding studies investigating the relationships among different activated proinflammatory processes suitable for targeting by different available drugs. The final objective is to clarify the state of the art in the field of personalized medicine for psoriatic disease, aiming at moving beyond the current treatment schedules toward a patient-centered approach

    Can Fraction of Inspired Oxygen Predict Extubation Failure in Preterm Infants?

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    Background: Prolonged mechanical ventilation in preterm infants may cause complications. We aimed to analyze the variables affecting extubation outcomes in preterm infants at high risk of extubation failure. Methods: This was a single-center, observational, retrospective study. Extubation failure was defined as survival with the need for reintubation within 72 h. Successfully extubated neonates (group 1) were compared to those with failed extubation (group 2). Multivariate logistic regression analysis evaluated factors that predicted extubation outcomes. Results: Eighty infants with a birth weight under 1000 g and/or gestational age (GA) under 28 weeks were included. Extubation failure occurred in 29 (36.2%) and success in 51 (63.8%) neonates. Most failures (75.9%) occurred within 24 h. Pre-extubation inspired oxygen fraction (FiO2) of 27% had a sensitivity of 58.6% and specificity of 64.7% for extubation failure. Post-extubation FiO2 of 32% had a sensitivity of 65.5% and specificity of 62.8% for failure. Prolonged membrane rupture (PROM) and high GA were associated with extubation success in multivariate logistic regression analysis. Conclusions: High GA and PROM were associated with extubation success. Pre-and post-extubation FiO2 values were not significantly predictive of extubation failure. Further studies should evaluate if overall assessment, including ventilatory parameters and clinical factors, can predict extubation success in neonates

    Defective endoplasmic reticulum-mitochondria contacts and bioenergetics in SEPN1-related myopathy

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    SEPN1-related myopathy (SEPN1-RM) is a muscle disorder due to mutations of the SEPN1 gene, which is characterized by muscle weakness and fatigue leading to scoliosis and life-threatening respiratory failure. Core lesions, focal areas of mitochondria depletion in skeletal muscle fibers, are the most common histopathological lesion. SEPN1-RM underlying mechanisms and the precise role of SEPN1 in muscle remained incompletely understood, hindering the development of biomarkers and therapies for this untreatable disease. To investigate the pathophysiological pathways in SEPN1-RM, we performed metabolic studies, calcium and ATP measurements, super-resolution and electron microscopy on in vivo and in vitro models of SEPN1 deficiency as well as muscle biopsies from SEPN1-RM patients. Mouse models of SEPN1 deficiency showed marked alterations in mitochondrial physiology and energy metabolism, suggesting that SEPN1 controls mitochondrial bioenergetics. Moreover, we found that SEPN1 was enriched at the mitochondria-associated membranes (MAM), and was needed for calcium transients between ER and mitochondria, as well as for the integrity of ER-mitochondria contacts. Consistently, loss of SEPN1 in patients was associated with alterations in body composition which correlated with the severity of muscle weakness, and with impaired ER-mitochondria contacts and low ATP levels. Our results indicate a role of SEPN1 as a novel MAM protein involved in mitochondrial bioenergetics. They also identify a systemic bioenergetic component in SEPN1-RM and establish mitochondria as a novel therapeutic target. This role of SEPN1 contributes to explain the fatigue and core lesions in skeletal muscle as well as the body composition abnormalities identified as part of the SEPN1-RM phenotype. Finally, these results point out to an unrecognized interplay between mitochondrial bioenergetics and ER homeostasis in skeletal muscle. They could therefore pave the way to the identification of biomarkers and therapeutic drugs for SEPN1-RM and for other disorders in which muscle ER-mitochondria cross-talk are impaired

    Triadin/Junctin Double Null Mouse Reveals a Differential Role for Triadin and Junctin in Anchoring CASQ to the jSR and Regulating Ca2+ Homeostasis

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    Triadin (Tdn) and Junctin (Jct) are structurally related transmembrane proteins thought to be key mediators of structural and functional interactions between calsequestrin (CASQ) and ryanodine receptor (RyRs) at the junctional sarcoplasmic reticulum (jSR). However, the specific contribution of each protein to the jSR architecture and to excitation-contraction (e-c) coupling has not been fully established. Here, using mouse models lacking either Tdn (Tdn-null), Jct (Jct-null) or both (Tdn/Jct-null), we identify Tdn as the main component of periodically located anchors connecting CASQ to the RyR-bearing jSR membrane. Both proteins proved to be important for the structural organization of jSR cisternae and retention of CASQ within them, but with different degrees of impact. Our results also suggest that the presence of CASQ is responsible for the wide lumen of the jSR cisternae. Using Ca2+ imaging and Ca2+ selective microelectrodes we found that changes in e-c coupling, SR Ca2+content and resting [Ca2+] in Jct, Tdn and Tdn/Jct-null muscles are directly correlated to the effect of each deletion on CASQ content and its organization within the jSR. These data suggest that in skeletal muscle the disruption of Tdn/CASQ link has a more profound effect on jSR architecture and myoplasmic Ca2+ regulation than Jct/CASQ association

    Regulation of differentiation of nitrogen-fixing bacteria by microsymbiont targeting of plant thioredoxin s1

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    Legumes associate with rhizobia to form nitrogen (N2)-fixing nodules, which is important for plant fitness [1, 2]. Medicago truncatula controls the terminal differentiation of Sinorhizobium meliloti into N2-fixing bacteroids by producing defensin-like nodule-specific cysteine-rich peptides (NCRs) [3, 4]. The redox state of NCRs influences some biological activities in free-living bacteria, but the relevance of redox regulation of NCRs in planta is unknown [5, 6], although redox regulation plays a crucial role in symbiotic nitrogen fixation [7, 8]. Two thioredoxins (Trx), Trx s1 and s2, define a new type of Trx and are expressed principally in nodules [9]. Here, we show that there are four Trx s genes, two of which, Trx s1 and s3, are induced in the nodule infection zone where bacterial differentiation occurs. Trx s1 is targeted to the symbiosomes, the N2-fixing organelles. Trx s1 interacted with NCR247 and NCR335 and increased the cytotoxic effect of NCR335 in S. meliloti. We show that Trx s silencing impairs bacteroid growth and endoreduplication, two features of terminal bacteroid differentiation, and that the ectopic expression of Trx s1 in S. meliloti partially complements the silencing phenotype. Thus, our findings show that Trx s1 is targeted to the bacterial endosymbiont, where it controls NCR activity and bacteroid terminal differentiation. Similarly, Trxs are critical for the activation of defensins produced against infectious microbes in mammalian hosts. Therefore, our results suggest the Trx-mediated regulation of host peptides as a conserved mechanism among symbiotic and pathogenic interactions

    JNK modulates FOXO3a for the expression of the mitochondrial death and mitophagy marker BNIP3 in pathological hypertrophy and in heart failure

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    Bcl-2 E1B 19-KDa interacting protein 3 (BNIP3) is a mitochondrial death and mitophagy marker, which is involved in inducing cardiac remodeling post myocardial infarction. In this study, we show that BNIP3 expression increases in stressed cardiomyocytes in vitro and in response to pressure overload in vivo, and that its transcription is directly related to JNK activity. BNIP3 expression gradually increased in the first weeks after pressure overload and peaked at the heart failure stage. Ultrastructurally, the mitochondrial area was inversely proportional to BNIP3 expression. Both JNK and AKT activities increased with pressure overload; however, JNK signaling dominated over AKT signaling for the activation of the transcription factor FOXO3a and for the transcription of its effector, BNIP3. 3-methyladenine attenuated JNK signaling and significantly decreased BNIP3 expression and reversed cardiac remodeling in heart failure. Ultrastructurally, the mitochondrial area was significantly increased in the 3-methyladenine group compared with placebo. Moreover, adenoviral gene delivery of dominant negative JNK in a rat model of pressure overload hypertrophy abolished the increase in BNIP3 expression in response to pressure overload. These results suggest that JNK signaling is a critical modulator of the transcription factor FOXO3a driving the expression of its effector, BNIP3, in heart failure and that JNK, through BNIP3, induces mitochondrial apoptosis and mitophagy

    Increased Muscle Stress-Sensitivity Induced by Selenoprotein N Inactivation in Mouse: A Mammalian Model for SEPN1-Related Myopathy

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    Selenium is an essential trace element and selenoprotein N (SelN) was the first selenium-containing protein shown to be directly involved in human inherited diseases. Mutations in the SEPN1 gene, encoding SelN, cause a group of muscular disorders characterized by predominant affection of axial muscles. SelN has been shown to participate in calcium and redox homeostasis, but its pathophysiological role in skeletal muscle remains largely unknown. To address SelN function in vivo, we generated a Sepn1-null mouse model by gene targeting. The Sepn1−/− mice had normal growth and lifespan, and were macroscopically indistinguishable from wild-type littermates. Only minor defects were observed in muscle morphology and contractile properties in SelN-deficient mice in basal conditions. However, when subjected to challenging physical exercise and stress conditions (forced swimming test), Sepn1−/− mice developed an obvious phenotype, characterized by limited motility and body rigidity during the swimming session, as well as a progressive curvature of the spine and predominant alteration of paravertebral muscles. This induced phenotype recapitulates the distribution of muscle involvement in patients with SEPN1-Related Myopathy, hence positioning this new animal model as a valuable tool to dissect the role of SelN in muscle function and to characterize the pathophysiological process

    Clinical features and therapeutic management of patients admitted to Italian acute hospital psychiatric units: the PERSEO (psychiatric emergency study and epidemiology) survey

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    <p>Abstract</p> <p>Background</p> <p>The PERSEO study (psychiatric emergency study and epidemiology) is a naturalistic, observational clinical survey in Italian acute hospital psychiatric units, called SPDCs (Servizio Psichiatrico Diagnosi e Cura; in English, the psychiatric service for diagnosis and management). The aims of this paper are: (i) to describe the epidemiological and clinical characteristics of patients, including sociodemographic features, risk factors, life habits and psychiatric diagnoses; and (ii) to assess the clinical management, subjective wellbeing and attitudes toward medications.</p> <p>Methods</p> <p>A total of 62 SPDCs distributed throughout Italy participated in the study and 2521 patients were enrolled over the 5-month study period.</p> <p>Results</p> <p>Almost half of patients (46%) showed an aggressive behaviour at admission to ward, but they engaged more commonly in verbal aggression (38%), than in aggression toward other people (20%). A total of 78% of patients had a psychiatric diagnosis at admission, most frequently schizophrenia (36%), followed by depression (16%) and personality disorders (14%), and no relevant changes in the diagnoses pattern were observed during hospital stay. Benzodiazepines were the most commonly prescribed drugs, regardless of diagnosis, at all time points. Overall, up to 83% of patients were treated with neuroleptic drugs and up to 27% received more than one neuroleptic either during hospital stay or at discharge. Atypical and conventional antipsychotics were equally prescribed for schizophrenia (59 vs 65% during stay and 59 vs 60% at discharge), while atypical drugs were preferred in schizoaffective psychoses (72 vs 49% during stay and 70 vs 46% at discharge) and depression (41 vs 32% during stay and 44 vs 25% at discharge). Atypical neuroleptics were slightly preferred to conventional ones at hospital discharge (52 vs 44%). Polypharmacy was in general widely used. Patient attitudes toward medications were on average positive and self-reported compliance increased during hospital stay.</p> <p>Conclusion</p> <p>Results confirm the widespread use of antipsychotics and the increasing trend in atypical drugs prescription, in both psychiatric in- and outpatients.</p
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