175 research outputs found

    First steps to define murine amniotic fluid stem cell microenvironment

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    Stem cell niche refers to the microenvironment where stem cells reside in living organisms. Several elements define the niche and regulate stem cell characteristics, such as stromal support cells, gap junctions, soluble factors, extracellular matrix proteins, blood vessels and neural inputs. In the last years, different studies demonstrated the presence of cKit+ cells in human and murine amniotic fluid, which have been defined as amniotic fluid stem (AFS) cells. Firstly, we characterized the murine cKit+ cells present both in the amniotic fluid and in the amnion. Secondly, to analyze the AFS cell microenvironment, we injected murine YFP+ embryonic stem cells (ESC) into the amniotic fluid of E13.5 wild type embryos. Four days after transplantation we found that YFP+ sorted cells maintained the expression of pluripotency markers and that ESC adherent to the amnion were more similar to original ESC in respect to those isolated from the amniotic fluid. Moreover, cytokines evaluation and oxygen concentration analysis revealed in this microenvironment the presence of factors that are considered key regulators in stem cell niches. This is the first indication that AFS cells reside in a microenvironment that possess specific characteristics able to maintain stemness of resident and exogenous stem cells

    Scaling in temporal occurrence of quasi-rigid-body vibration pulses due to macrofractures

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    We subjected the time series of quasi-rigid-body vibration pulses (elastic emissions) from laboratory fracture carried out by a piezoelectric accelerometer on concrete and rock specimens under uniaxial compression to statistical analysis. In both cases, we find that the waiting-time distribution can be described by a scaling law extending over several orders of magnitude. This law is indistinguishable from a universal scaling law recently proposed for the waiting-time distributions of acoustic emissions in heterogeneous materials and earthquakes, suggesting its general validity for fracture processes independent of modes and magnitude scales

    Modified Mason type III and IV radial head fractures: results of different surgical treatments

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    Fractures of the radial head account for 4% of all fractures and 33 % of all elbow fractures. Their treatment is somewhat challenging and diversified, especially in more complex fractures (type III and IV of modified Mason's classification). The aim of this study was to identify the best surgical treatment for patients having sustained these latter lesions and outline possible predictive factors of worse outcomes

    The G Protein regulators EGL-10 and EAT-16, the Giα GOA-1 and the Gqα EGL-30 modulate the response of the C. elegans ASH polymodal nociceptive sensory neurons to repellents

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    <p>Abstract</p> <p>Background</p> <p>Polymodal, nociceptive sensory neurons are key cellular elements of the way animals sense aversive and painful stimuli. In <it>Caenorhabditis elegans</it>, the polymodal nociceptive ASH sensory neurons detect aversive stimuli and release glutamate to generate avoidance responses. They are thus useful models for the nociceptive neurons of mammals. While several molecules affecting signal generation and transduction in ASH have been identified, less is known about transmission of the signal from ASH to downstream neurons and about the molecules involved in its modulation.</p> <p>Results</p> <p>We discovered that the regulator of G protein signalling (RGS) protein, EGL-10, is required for appropriate avoidance responses to noxious stimuli sensed by ASH. As it does for other behaviours in which it is also involved, <it>egl-10 </it>interacts genetically with the G<sub>o/i</sub>α protein GOA-1, the G<sub>q</sub>α protein EGL-30 and the RGS EAT-16. Genetic, behavioural and Ca<sup>2+ </sup>imaging analyses of ASH neurons in live animals demonstrate that, within ASH, EGL-10 and GOA-1 act downstream of stimulus-evoked signal transduction and of the main transduction channel OSM-9. EGL-30 instead appears to act upstream by regulating Ca<sup>2+ </sup>transients in response to aversive stimuli. Analysis of the delay in the avoidance response, of the frequency of spontaneous inversions and of the genetic interaction with the diacylglycerol kinase gene, <it>dgk-1</it>, indicate that EGL-10 and GOA-1 do not affect signal transduction and neuronal depolarization in response to aversive stimuli but act in ASH to modulate downstream transmission of the signal.</p> <p>Conclusions</p> <p>The ASH polymodal nociceptive sensory neurons can be modulated not only in their capacity to detect stimuli but also in the efficiency with which they respond to them. The Gα and RGS molecules studied in this work are conserved in evolution and, for each of them, mammalian orthologs can be identified. The discovery of their role in the modulation of signal transduction and signal transmission of nociceptors may help us to understand how pain is generated and how its control can go astray (such as chronic pain) and may suggest new pain control therapies.</p

    Do methadone and buprenorphine have the same impact on psychopathological symptoms of heroin addicts?

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    <p>Abstract</p> <p>Background</p> <p>The idea that the impact of opioid agonist treatment is influenced by the psychopathological profile of heroin addicts has not yet been investigated, and is based on the concept of a specific therapeutic action displayed by opioid agents on psychopathological symptoms. In the present report we compared the effects of buprenorphine and methadone on the psychopathological symptoms of 213 patients (106 on buprenorphine and 107 on methadone) in a follow-up study lasting 12 months.</p> <p>Methods</p> <p>Drug addiction history was collected by means of the Drug Addiction History Rating Scale (DAH-RS) and psychopathological features were collected by means of the Symptom Checklist-90 (SCL-90), using a special five-factor solution. Toxicological urinalyses were carried out for each patient during the treatment period.</p> <p>Results</p> <p>No statistically significant differences were detected in psychopathological symptoms, including 'worthlessness-being trapped', 'somatization', and 'panic-anxiety'. Methadone proved to be more effective on patients characterized by 'sensitivity-psychoticism', whereas buprenorphine was more effective on patients displaying a 'violence-suicide' symptomatology.</p> <p>Conclusions</p> <p>Heroin-dependent patients with psychiatric comorbidities may benefit from opioid agonist treatment not only because it targets their addictive problem, but also, precisely due to this, because it is effective against their mental disorder too.</p

    EDIFICI IN MURATURA DI PIETRA: PREVENZIONE SISMICA, PRESTAZIONI ACUSTICHE ED ENERGETICHE

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    Le murature portanti realizzate con materiali lapidei naturali costituiscono una risorsa per la ricostruzione di aree devastate da eventi sismici nell’ottica di recuperare, oltre ad una maggiore sicurezza antisismica, anche un’identità storico-tipologica del tessuto urbano, unitamente alla possibilità di rilanciare le attività edilizie artigianali delle economie locali. Nella memoria si indagano sinteticamente le tecnologie costruttive in muratura ammesse dalle normative antisismiche, alla luce del fatto che le stesse offrono interessanti prestazioni acustiche ed energetiche, grazie all’elevata massa ed inerzia termica, aspetti anch’essi oggetto di specifiche normative cogenti

    Safety and Feasibility of MitraClip Implantation in Patients with Acute Mitral Regurgitation after Recent Myocardial Infarction and Severe Left Ventricle Dysfunction

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    Patients with severe mitral regurgitation (MR) after myocardial infarction (MI) have an increased risk of mortality. Transcatheter mitral valve repair may therefore be a suitable therapy. However, data on clinical outcomes of patients in an acute setting are scarce, especially those with reduced left ventricle (LV) dysfunction. We conducted a multinational, collaborative data analysis from 21 centers for patients who were, within 90 days of acute MI, treated with MitraClip due to severe MR. The cohort was divided according to median left ventricle ejection fraction (LVEF)-35%. Included in the study were 105 patients. The mean age was 71 ± 10 years. Patients in the LVEF \u3c 35% group were younger but with comparable Euroscore II, multivessel coronary artery disease, prior MI and coronary artery bypass graft surgery. Procedure time was comparable and acute success rate was high in both groups (94% vs. 90%, p = 0.728). MR grade was significantly reduced in both groups along with an immediate reduction in left atrial V-wave, pulmonary artery pressure and improvement in New York Heart Association (NYHA) class. In-hospital and 1-year mortality rates were not significantly different between the two groups (11% vs. 7%, p = 0.51 and 19% vs. 12%, p = 0.49) and neither was the 3-month re-hospitalization rate. In conclusion, MitraClip intervention in patients with acute severe functional mitral regurgitation (FMR) due to a recent MI in an acute setting is safe and feasible. Even patients with severe LV dysfunction may benefit from transcatheter mitral valve intervention and should not be excluded
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