85 research outputs found

    Il sistema di allenamento analogico/simbolico nello sport della pallavolo: Una valutazione delle componenti mnesitico/attentive

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    I benefici che l’attività motoria opera sia nell’età adulta che durante l’infanzia sono molteplici. Tra questi, si annoverano i miglioramenti delle abilità percettive, attentive e mnestiche. Lo scopo del presente lavoro è verificare se le capacità mnestiche ed attentive possano essere incrementate dalla messa in opera di un’offerta formativa specifica. Due gruppi di bambini, di età compresa tra i sei e i dieci anni sono stati avviati al gioco della pallavolo. Un gruppo è stato allenato con un metodo che carica di significati i movimenti corporei dell’allenatore e dei compagni al fine di associare tali movimenti allo svolgimento di future indicazioni da eseguire (Pittera, Pedata e Ligas, 2008). L’altro gruppo ha svolto esercizi propedeutici alla pallavolo attraverso la focalizzazione sull’apprendimento dei gesti tecnici. La differenza tra i dati raccolti all’inizio e alla fine del periodo di allenamento preso in esame evidenziarono un miglioramento della capacità di ricordare azioni motorie; nessun miglioramento apparve però per quanto ha riguardato il numero di posizioni spaziali o il numero di componenti verbali da ricordare. Sorprendentemente, poi, nessun miglioramento emerse nelle misure di attenzione sostenuta. I risultati suggeriscono come, focalizzando l’attenzione dei discenti sugli aspetti motori dell’esercizio, e facendo in modo che questi aumentino di significato al fine della successiva realizzazione di nuovi compiti, si possa aumentare una capacità basilare di ogni apprendimento sportivo, ovvero la capacità di ricordare nuove azioni

    Scintigraphy-based analysis of possible pulmonary lesions after foam sclerotherapy: a pilot study

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    The aims of this study were to assess extemporaneous in vivo binding between 99mTcO4- and two sclerosant detergents in foam sclerotherapy, and subsequently to control any possible damage in lungs and other organs related to sclerosant foam passage. A prospective comparative pilot study was performed on two male patients (62 and 56 years old) affected by varicose veins; each of them underwent scintigraphy investigations with free radiotracer and a scintigraphy investigation after each of the four sessions of sclerotherapy of varicose tributaries of the lower limbs with labeled sclerosant foam. One of the two patients underwent two further scintigraphic investigations, with free radiotracer and with labeled sclerosant foam, at a later stage. Four mL of 2% polidocanol (POL) foam, or four mL of 1% sodiumtetradecylsulfate (STS) foam for session were injected. The sclerosant foam was labeled with the radioactive tracer technetium pertechnetate, 99mTcO4- (120 MBq per exam). Two scintigraphy assessments for free tracer (basal) and five scintigraphy investigations of bound-tosclerosant tracer uptake/transit were obtained. No relevant variations in time/activity curves of the lungs and other organs were documented between the basal and post-sclerotherapy findings, also at the later stage. Free radiotracer mean region-of-interest data were: 336 counts (heart), 208 counts (lungs) and 371 counts (thyroid). Mean values extrapolated from each curve at each step for labeled CO2O2-based sclerosant foam were respectively: 351 counts (POL) and 328 counts (STS) for heart, 202 counts (POL) and 188 counts (STS) for lungs, 335 (POL) and 263 (STS) for thyroid. No pulmonary damage by sclerosant foam was caused. Neither immediately after treatments, nor at short-term follow-up

    Timing and modality of the sclerosing agents binding to the human proteins: laboratory analysis and clinical evidences

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    Sclerosing agents (SA) are blood inactivated. Nevertheless, investigations concerning the interaction among SA and blood components have never been deeply investigated. Aim of the study is to precisely identify SA blood ligands, to determine their binding time and to highlight the clinical consequences. Thirty-one blood samples were collected from chronic venous disease patients and tested by capillary and agarose gel (AGE) electrophoresis before and after adding polidocanol (POL) and sodiumtetradecylsulphate (STS). The two different types of electrophoresis allowed an evaluation of the blood proteins binding with the sclerosing agents, with a reaction time lower than 8 seconds for the AGE. Subsequently six patients underwent foam sclerotherapy and then were subdivided in group A (4 patients) and B (2 patients). In group A blood sample was obtained from the ipsilateral brachial vein immediately before (T0) and repeated 1, 3, 5, and 10 minutes after injection of STS 3% injection into the GSV. In group B, the same procedure was performed with the same timing from the ipsilateral femoral vein. Free STS (fSTS) and total proteinbound STS (bSTS) were measured. POL mainly binds to β-globulins (11%), while STS to albumin and α-globulins (62.6% and 30.7%) on the protidogram, respectively. Both in the brachial and in the femoral vein, the average fSTS was always 0. STS binds to albumin (62.6%) and α-globulins (30.7%), while POL is bound mainly by the b-globulins (11%). The present paper demonstrates how the vast majority of the sclerosing agent is bound to the blood proteins, suggesting the need to look for possible sclerotherapy complications factors also in the used gas and/or in the subsequent cathabolites release

    STIMA: a short screening test for ideo-motor apraxia, selective for action meaning and bodily district

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    We propose STIMA, a short test for ideo-motor apraxia, allowing us to quantify the apraxic deficit according to action meaning and affected body segment. STIMA is based on a neurocognitive model holding that there are two processes involved in action imitation (i.e., a semantic route for recognizing and imitating known gestures, and a direct route for reproducing new gestures). The test allows to identify which imitative process has been selectively impaired by brain damage (direct vs. semantic route) and possible deficits depending on the body segment involved (hand/limb vs. hand/fingers). N = 111 healthy participants were administered with an imitation task in two separated blocks of known and new gestures. In each block, half of the gestures were performed mainly with the proximal part of the upper limb and the remaining half with the distal one. It resulted in 18 known gestures (nine proximal and nine distal) and 18 new gestures (nine proximal and nine distal) for a total of 36. Each gesture was presented up to a maximum of two times. Detailed criteria are used to assign the final imitation score. Cut offs, equivalent scores and main percentile scores were computed for each subscale. Participants imitated better known than new gestures, and proximal better than distal gestures. Age influenced performance on all subscales, while education only affected one subscale. STIMA is easy and quick to administer, and compared to previous tests, it offers important information for planning adequate rehabilitation programs based on the functional locus of the deficit

    Conformational equilibria in monomeric alpha-synuclein at the single molecule level

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    Natively unstructured proteins defy the classical "one sequence-one structure" paradigm of protein science. Monomers of these proteins in pathological conditions can aggregate in the cell, a process that underlies socially relevant neurodegenerative diseases such as Alzheimer and Parkinson. A full comprehension of the formation and structure of the so-called misfolded intermediates from which the aggregated states ensue is still lacking. We characterized the folding and the conformational diversity of alpha-synuclein (aSyn), a natively unstructured protein involved in Parkinson disease, by mechanically stretching single molecules of this protein and recording their mechanical properties. These experiments permitted us to directly observe directly and quantify three main classes of conformations that, under in vitro physiological conditions, exist simultaneously in the aSyn sample, including disordered and "beta-like" structures. We found that this class of "beta-like" structures is directly related to aSyn aggregation. In fact, their relative abundance increases drastically in three different conditions known to promote the formation of aSyn fibrils: the presence of Cu2+, the occurrence of the pathogenic A30P mutation, and high ionic strength. We expect that a critical concentration of aSyn with a "beta-like" structure must be reached to trigger fibril formation. This critical concentration is therefore controlled by a chemical equilibrium. Novel pharmacological strategies can now be tailored to act upstream, before the aggregation process ensues, by targeting this equilibrium. To this end, Single Molecule Force Spectroscopy can be an effective tool to tailor and test new pharmacological agents.Comment: 37 pages, 9 figures (including supplementary material

    A step-by-step problem-solving strategy in a patient with heart failure and cerebral aneurysm

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    Left ventricular assist devices (LVAD) implantation is an established treatment for patients with end-stage heart failure. HeartMate 3 (HM3) is a continuous-flow centrifugal pump, recently introduced in the clinic, which has shown greater hemocompatibility compared to similar devices of previous generations. Nevertheless, anticoagulation is still required after HM3 implant to avoid pump dysfunction. Hereafter, we describe the case of a patient candidate to LVAD implantation for end-stage heart failure presenting a concomitant cerebrovascular lesion, accidentally found during pre-operative assessment, which would have contraindicated the procedure (for the prohibitive risk of cerebral hemorrhage), unless a step by step problem-solving approach was adopted

    Venous compliance and clinical implications

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    Compliance is a characteristic of every deformable system. Compliance is very clear concept in physics and mechanics but in clinics, perhaps, is not the same. However, in veins compliance fits perfectly with the function of drainage of the venous system. Volumetric increase (dV) of the content is correlated with pressure increase (dP) inside the vein according to the equation C'= dV/dP. In humans 75% of the blood is located in the venous system, primarily because the molecular components of a vein media layer is significantly more compliant to that of arteries. This property is fundamental to understanding the change in blood volume in response to a change in posture. Measurements of venous compliance in clinical practice can be done by the means of ultrasound, as well as with the plethysmography. Ultrasound methods assimilate the cross sectional area to the volume of the vein, because it reflects the blood content. Changes in cross sectional area can be reliably measured in response to a change in posture, while pressure can be derived from the hydrostatic pressure changes. Venous compliance is of paramount importance also in pulsatile veins such as the inferior or superior vena cava and the jugular veins, where high resolution ultrasound may accurately derive the cross sectional area. Clinical implications of the mechanical properties of the venous wall are extensively discussed, including the need of dedicated venous stenting, which takes into account venous compliance as the main parameter of the venous function. In addition, venous compliance is the interpretative key for a better understanding of plethysmography curves, as well as of varicose veins and of their return to normal cross sectional area following ambulatory venous pressure reduction

    On the consistency of flow rate color Doppler assessment for the internal jugular vein

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    Color Doppler methodology to assess the vessel blood flow rate is based on the time averaged velocity of the blood measured in the longitudinal plane and the cross sectional area measurement taken either in the longitudinal plane, by assuming circular cross sectional area, or in the transversal plane. The measurement option in longitudinal plane is based on the assumption of circular cross sectional area, while the transversal one needs to evaluate both time-averaged velocity and cross sectional area in the same vessel point. A precise and validated assessment methodology is still lacking. Four healthy volunteers underwent internal jugular vein colour Doppler scanning. The cross sectional area was assessed by means of B-mode imaging in the transversal plane all along the vessel cervical course. During this assessment, cross sectional area, major and minor axis of the vessel were measured and recorded. The distance between the internal jugular vein wall and the skin surface were measured together with the intra-luminal diameter and statistically correlated with the cross sectional area data. The internal jugular vein cross sectional area measured on the transversal plane were significantly different from the cross sectional area calculated using the assumption of circular shape. The intra-luminal distance showed high correlation with the measured cross sectional area. The proper anatomical point in the cross sectional area transversal measurement can be identified by using the internal jugular vein intra-luminal distance as landmark

    Synthesis and hyperpolarisation of eNOS substrates for quantification of NO production by 1H NMR spectroscopy

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    Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an l-Arg- to l-Cit-derivative by 1H NMR spectroscopy - is herein proposed. A small library of pyridyl containing l-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2 - production=19-46μM) than native l-Arg (NO2 - production=25μM). Enzymatic conversion of l-Arg to l-Cit derivatives could be monitored by 1H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo
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