655 research outputs found
ADVANCED TECHNOLOGIES AND METHODOLOGIES FOR REHABILITATION
Frequently athletes are affected by lesions to muscles, joints, bone and nervous systems. The medical treatment and the subsequent rehabilitation in most cases are able to lead to a complete recovery. TWO points should be considered: a) the designing of most appropriate training and rehabilitation procedures should take into account the specific characteristics of the athlete and of his specialization. b) The recovery, which could be considered acceptable for a "normal subject", not always is completely appropriate for an athlete who has to face superior motor performances. c) A detailed solution is needed in order to decide when and how to restart the normal activity of training and full performance. In this frame, the traditional analysis of correlation between the localisation of the lesion and the deficit of function appears insufficient to obtain the maximum potential recovery, given a certain damage. Only by taking into account a quantitative multifactorial analysis of the motor function in relation with the lesion and the expected recovery, optimal resulta could be reached from medical rehabilitation and training. This implies several steps: - a detailed functional evaluation of each athlete; - a continuous monitoring of the athlete's progress / and consequent adaptation of training itself. In this context, a detailed multifactor analysis assumes a central role. The traditional evaluation performed by visual inspection appears insufficient for these purposes. ' Kinematics, dynamics, neuromuscular events and correlations among these variables must be considered in a quantitative way. The use of advanced technology (transducers, microprocessors, etc.) can provide useful means; because it is possible to develop very complex instrumentations (complex in terms of variables measured and data processing), which require relatively easy tests, feasible also in clinical environment or gymnasium
Halpha surface photometry of galaxies in the Virgo cluster. IV: the current star formation in nearby clusters of galaxies
Halpha+[NII] imaging observations of 369 late-type galaxies in the Virgo
cluster and in the Coma/A1367 supercluster are analyzed. They constitute an
optically selected sample (m_p<16.0) observed with 60% c.a. completeness.These
observations provide us with the current (T<10^7 yrs) star formation properties
of galaxies. The expected decrease of the star formation rate (SFR),as traced
by the Halpha E.W., with decreasing clustercentric projected distance is found
only when galaxies brighter than M_p=-19.5 are considered. We also include in
our analysis Near Infrared data, providing us with informations on the old
(T>10^9yrs) stars. Put together, the young and the old stellar indicators give
the ratio of currently formed stars over the stars formed in the past, or
"birthrate" parameter b. We also determine the "global gas content" combining
HI with CO observations. We define the "gas deficiency" parameter as the
logarithmic difference between the gas content of isolated galaxies of a given
Hubble type and the measured gas content.For the isolated objects we find that
b decreases with increasing NIR luminosity. The gas-deficient objects,
primarily members to the Virgo cluster, have their birthrate significantly
lower than the isolated objects with normal gas content and of similar NIR
luminosity. This indicates that the current star formation is regulated by the
gaseous content of spirals.Whatever mechanism (most plausibly ram-pressure
stripping) is responsible for the pattern of gas deficiency observed in spiral
galaxies members to rich clusters, it also produces the observed quenching of
the current star formation.Comment: 22 pages,14 figures,3 figures available in jpeg format.To be
published in A&
AEROBIC AND ANAEROBIC METABOLISM DURING LOCOMOTION WITH TWO DIFFERENT WHEELCHAIR TYPES
Wheelchair design is extremely important in order to improve efficiency of locomotion and reduce physical stress in subjects whose muscular and cardiopulmonary fitness are impaired. Purpose of this study was to evaluate the effect of different wheelchair design on the aerobic and anaerobic metabolism during locomotion at different speeds in paraplegic subjects. The experiments were carried out on a group of 5 male paraplegic subjects (25 ±3 years; body weight 65±7kg) during locomotion on a roller ergometer (Sopur, Ergotronic mod.) at 3-4 different speeds from 2 to 9 km/h. At each speed oxygen consumption and heart rate were determined after at least 6 min of exercise. Lactic acid (LA) venous blood concentration was evaluated before and at the 5th min of recovery and lactate production was calculated. The oxygen equivalent of LA was assumed to be 3.15ml O2 per kg body weight for an increase of blood LA of 1 mmol/L. For each subject the test was repeated using two different types of daily use active wheelchairs: type A., foldable, 13.95kg; type B, demountable, 13.35kg. The main difference in size was in the horizontal location of the wheel axle, in seat height and in handrim diameter. Results indicate that: a) oxygen consumption increased linearly with speed being 2050±350ml/min and 1780±270ml/min at 9km/h for wheelchair type A and B, respectively; b)lactic acid concentrations were significantly higher, at a given speed, while using wheelchair type A than B (at 9km/h; 7.4±1.5 mmol/l and 6.0±1.6 mmol/l, respectively),c) the total energy required , aerobic and anaerobic, increased linearly with speed and was 15-20% higher with wheelchair type A than B at all speeds; d) the energy cost of locomotion at a given speed was in the 15-25% range higher for wheelchair A than B; e) at corresponding oxygen uptake, heart rate and pulmonary ventilation were not different with the two wheelchair types. The main results of this study concern the large difference existing in the energy cost of locomotion and in the lactate production in the same subject when two different wheelchairs, even if apparently similar are used. In particular the much higher lactate production suggests that wheelchair design affects the limb and trunk movements in such a way that the metabolism of some muscle group requires a greater participation of anaerobic mechanism of energy supply, this leading to early onset of muscular fatigue. Further studies, in particular the combined biomechanical analysis of user and wheelchair during locomotion are required to increase the optimum fitting of wheelchair –user interface
Optical spectroscopy of galaxies in the direction of the Virgo cluster
Optical spectroscopy of 76 galaxies, 48 of which are projected in the
direction of the Virgo cluster and 28 onto the Coma-A1367 supercluster, is
reported. Adding these new measurements to those found in the literature, the
redshift completeness in the Virgo region becomes 92% at B_T<=16.0 and 68% at
B_T<=18.0. The one of CGCG galaxies in the direction of the Coma-A1367
supercluster becomes 98%. The Virgo cluster membership estimates obtained on
morphological grounds by Binggeli et al. (1985) are confirmed in all cases.
However, several "possible members" classified as BCD (if in the cluster) are
found instead to be giant emission-line galaxies in the background of the Virgo
clusterComment: LaTeX, 8 pages, 5 figures, accepted for pubblication in A&
Mast cells counteract regulatory T-cell suppression through interleukin-6 and OX40/OX40L axis toward Th17-cell differentiation
The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell-derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17-producing T cells (Th17). In vivo analysis of lymph nodes hosting T-cell priming in experimental autoimmune encephalomyelitis revealed activated MCs, Tregs, and Th17 cells displaying tight spatial interactions, further supporting the occurrence of an MC-mediated inhibition of Treg suppression in the establishment of Th17-mediated inflammatory responses. © 2009 by The American Society of Hematology
Actual performance of mechanical ventilators in ICU: a multicentric quality control study.
Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH(2)O/L/s) - elastance (100 mL/cmH(2)O) test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66). Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP) = 8 cmH(2)O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min-max) of the ventilatory parameters were the following: inspired tidal volume = 607 ± 36 (530-723) mL, expired tidal volume = 608 ± 36 (530-728) mL, peak pressure = 20.8 ± 2.3 (17.2-25.9) cmH(2)O, respiratory rate = 20.09 ± 0.35 (19.5-21.6) breaths/minute, PEEP = 8.43 ± 0.57 (7.26-10.8) cmH(2)O, oxygen fraction = 0.49 ± 0.014 (0.41-0.53). The more error-prone parameters were the ones related to the measure of flow. In several cases, the actual delivered mechanical ventilation was considerably different from the set one, suggesting the need for improving quality control procedures for these machines
CD8+ T cells specific for cryptic apoptosis-associated epitopes exacerbate experimental autoimmune encephalomyelitis
The autoimmune immunopathology occurring in multiple sclerosis (MS) is sustained by myelin-specific and -nonspecific CD8(+) T cells. We have previously shown that, in MS, activated T cells undergoing apoptosis induce a CD8(+) T cell response directed against antigens that are unveiled during the apoptotic process, namely caspase-cleaved structural proteins such as non-muscle myosin and vimentin. Here, we have explored in vivo the development and the function of the immune responses to cryptic apoptosis-associated epitopes (AEs) in a well-established mouse model of MS, experimental autoimmune encephalomyelitis (EAE), through a combination of immunization approaches, multiparametric flow cytometry, and functional assays. First, we confirmed that this model recapitulated the main findings observed in MS patients, namely that apoptotic T cells and effector/memory AE-specific CD8(+) T cells accumulate in the central nervous system of mice with EAE, positively correlating with disease severity. Interestingly, we found that AE-specific CD8(+) T cells were present also in the lymphoid organs of unprimed mice, proliferated under peptide stimulation in vitro, but failed to respond to peptide immunization in vivo, suggesting a physiological control of this response. However, when mice were immunized with AEs along with EAE induction, AE-specific CD8(+) T cells with an effector/memory phenotype accumulated in the central nervous system, and the disease severity was exacerbated. In conclusion, we demonstrate that AE-specific autoimmunity may contribute to immunopathology in neuroinflammation
Tackling amyloidogenesis in Alzheimer's disease with A2V variants of Amyloid-β
We developed a novel therapeutic strategy for Alzheimer’s disease (AD) exploiting the properties of a natural variant of Amyloid-β (Aβ) carrying the A2V substitution, which protects heterozygous carriers from AD by its ability to interact with wild-type Aβ, hindering conformational changes and assembly thereof. As prototypic compound we designed a six-mer mutated peptide (Aβ1-6A2V), linked to the HIV-related TAT protein, which is widely used for brain delivery and cell membrane penetration of drugs. The resulting molecule [Aβ1-6A2VTAT(D)] revealed strong anti-amyloidogenic effects in vitro and protected human neuroblastoma cells from Aβ toxicity. Preclinical studies in AD mouse models showed that short-term treatment with Aβ1-6A2VTAT(D) inhibits Aβ aggregation and cerebral amyloid deposition, but a long treatment schedule unexpectedly increases amyloid burden, although preventing cognitive deterioration. Our data support the view that the AβA2V-based strategy can be successfully used for the development of treatments for AD, as suggested by the natural protection against the disease in human A2V heterozygous carriers. The undesirable outcome of the prolonged treatment with Aβ1-6A2VTAT(D) was likely due to the TAT intrinsic attitude to increase Aβ production, avidly bind amyloid and boost its seeding activity, warning against the use of the TAT carrier in the design of AD therapeutics
Accuracy of a questionnaire for identifying respiratory allergies in epidemiological studies
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Prophylactic and postexposure efficacy of a potent human monoclonal antibody against MERS coronavirus
Middle East Respiratory Syndrome coronavirus (MERS-CoV) causes severe respiratory disease with a high mortality rate. There is no licensed vaccine or antiviral for MERS. Here we isolated for the first time, to our knowledge, a potent MERS-CoV–neutralizing antibody from memory B cells of an infected individual. This antibody binds to a novel site on the viral Spike protein, neutralizes by interfering with the binding to the cellular receptor CD26, and is highly effective both in prophylaxis and in therapy in a relevant mouse model. This antibody can be developed for prophylaxis, for postexposure prophylaxis, or for the treatment of severe MERS-CoV infections
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