560 research outputs found

    Bilateral Assessment of Functional Tasks for Robot-assisted Therapy Applications

    Get PDF
    This article presents a novel evaluation system along with methods to evaluate bilateral coordination of arm function on activities of daily living tasks before and after robot-assisted therapy. An affordable bilateral assessment system (BiAS) consisting of two mini-passive measuring units modeled as three degree of freedom robots is described. The process for evaluating functional tasks using the BiAS is presented and we demonstrate its ability to measure wrist kinematic trajectories. Three metrics, phase difference, movement overlap, and task completion time, are used to evaluate the BiAS system on a bilateral symmetric (bi-drink) and a bilateral asymmetric (bi-pour) functional task. Wrist position and velocity trajectories are evaluated using these metrics to provide insight into temporal and spatial bilateral deficits after stroke. The BiAS system quantified movements of the wrists during functional tasks and detected differences in impaired and unimpaired arm movements. Case studies showed that stroke patients compared to healthy subjects move slower and are less likely to use their arm simultaneously even when the functional task requires simultaneous movement. After robot-assisted therapy, interlimb coordination spatial deficits moved toward normal coordination on functional tasks

    Absence of system xc⁻ on immune cells invading the central nervous system alleviates experimental autoimmune encephalitis

    Get PDF
    Background: Multiple sclerosis (MS) is an autoimmune demyelinating disease that affects the central nervous system (CNS), leading to neurodegeneration and chronic disability. Accumulating evidence points to a key role for neuroinflammation, oxidative stress, and excitotoxicity in this degenerative process. System x(c)- or the cystine/glutamate antiporter could tie these pathological mechanisms together: its activity is enhanced by reactive oxygen species and inflammatory stimuli, and its enhancement might lead to the release of toxic amounts of glutamate, thereby triggering excitotoxicity and neurodegeneration. Methods: Semi-quantitative Western blotting served to study protein expression of xCT, the specific subunit of system x(c)-, as well as of regulators of xCT transcription, in the normal appearing white matter (NAWM) of MS patients and in the CNS and spleen of mice exposed to experimental autoimmune encephalomyelitis (EAE), an accepted mouse model of MS. We next compared the clinical course of the EAE disease, the extent of demyelination, the infiltration of immune cells and microglial activation in xCT-knockout (xCT(-/-)) mice and irradiated mice reconstituted in xCT(-/-) bone marrow (BM), to their proper wild type (xCT(+/+)) controls. Results: xCT protein expression levels were upregulated in the NAWM of MS patients and in the brain, spinal cord, and spleen of EAE mice. The pathways involved in this upregulation in NAWM of MS patients remain unresolved. Compared to xCT(+/+) mice, xCT(-/-) mice were equally susceptible to EAE, whereas mice transplanted with xCT(-/-) BM, and as such only exhibiting loss of xCT in their immune cells, were less susceptible to EAE. In none of the above-described conditions, demyelination, microglial activation, or infiltration of immune cells were affected. Conclusions: Our findings demonstrate enhancement of xCT protein expression in MS pathology and suggest that system x(c)- on immune cells invading the CNS participates to EAE. Since a total loss of system x(c)- had no net beneficial effects, these results have important implications for targeting system x(c)- for treatment of MS

    A Comparative Neuroanatomical Study of the Red Nucleus of the Cat, Macaque and Human

    Get PDF
    BACKGROUND:The human red nucleus (Nr) is comparatively less well-studied than that of cats or monkeys. Given the functional importance of reticular and midbrain structures in control of movement and locomotion as well as from an evolutionary perspective, we investigated the nature and extent of any differences in Nr projections to the olivary complex in quadrupedal and bipedal species. Using neuroanatomical tract-tracing techniques we developed a "neural sheet" hypothesis allowing us to propose how rubro-olivary relations differ among the three species. METHODS AND FINDINGS:Wheat germ agglutinin-horseradish peroxidase staining supports findings that the cat's nucleus accessories medialis of Bechtrew (NB) projects mainly to the lateral bend of the principal olive. We clarified boundaries among nucleus of Darkschewitsch (ND), NB and parvicellular red nucleus (pNr) of the cat's neural sheet. The macaque's ND-medial accessory olivary projection is rostro-caudally organized and the dorsomedial and ventrolateral parts of the macaque's pNr may project to the principal olive's rostral and caudal dorsal lamella; in cat it projects as well to pNr. Myelin- and Nissl-stained sections show that a well-developed dorsomedial part of the human Nr consists of densely packed cells, deriving small myelinated fibers that continue into the medial central tegmental tract. CONCLUSIONS:Based on these findings we suggest there are distinct bipedal-quadrupedal differences for Nr projections to the olivary complex. We propose the Nr of cats and monkeys comprise the ND, NB and pNr in a zonal sheet-like structure, retaining clear nuclear boundaries and an isolated, well-developed mNr. The human NB may be distinguished from its more specialised ND (ND lies alongside a well-developed pNr) in the human central gray. Phylogenetically, the NB may have been translocated into a roll-shaped Nr in the reticular formation, the dorsomedial portion of which might correspond to the cat's and monkey's NB

    Carpal tunnel syndrome and the use of computer mouse and keyboard: A systematic review

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This review examines evidence for an association between computer work and carpal tunnel syndrome (CTS).</p> <p>Methods</p> <p>A systematic review of studies of computer work and CTS was performed. Supplementary, longitudinal studies of low force, repetitive work and CTS, and studies of possible pathophysiological mechanisms were evaluated.</p> <p>Results</p> <p>Eight epidemiological studies of the association between computer work and CTS were identified. All eight studies had one or more limitation including imprecise exposure and outcome assessment, low statistical power or potentially serious biases. In three of the studies an exposure-response association was observed but because of possible misclassification no firm conclusions could be drawn. Three of the studies found risks below 1. Also longitudinal studies of repetitive low-force non-computer work (n = 3) were reviewed but these studies did not add evidence to an association. Measurements of carpal tunnel pressure (CTP) under conditions typically observed among computer users showed pressure values below levels considered harmful. However, during actual mouse use one study showed an increase of CTP to potentially harmful levels. The long term effects of prolonged or repeatedly increased pressures at these levels are not known, however.</p> <p>Conclusion</p> <p>There is insufficient epidemiological evidence that computer work causes CTS.</p

    Patient-reported outcome measures for asthma:a systematic review

    Get PDF
    BACKGROUND: Patient-reported outcome measures (PROMs) are measures of the outcome of treatment(s) reported directly by the patient or carer. There is increasing international policy interest in using these to assess the impact of clinical care. AIMS: To identify suitably validated PROMs for asthma and examine their potential for use in clinical settings. METHODS: We systematically searched MEDLINE, EMBASE and Web of Science databases from 1990 onwards to identify PROMs for asthma. These were critically appraised, then narratively synthesised. We also identified the generic PROMs commonly used alongside asthma-specific PROMs. RESULTS: We identifi ed 68 PROMs for asthma, 13 of which were selected through screening as being adequately developed to warrant full-quality appraisal: 8 for adults, 4 for children and 1 for a child's caregiver. The PROMs found to be sufficiently well validated to offer promise for use in clinical settings were the Asthma Quality of Life Questionnaire (AQLQ) and mini-AQLQ for adults, and Pediatric Asthma Quality of Life Questionnaire for children. Rhinasthma was considered promising in simultaneously assessing the impact of asthma and rhinitis in those with coexistent disease. We identified 28 generic PROMs commonly used in conjunction with asthma-specific instruments. CONCLUSIONS: We identified asthma PROMs that offer the greatest potential for use in clinical settings. Further work is needed to assess whether these are fit-for-purpose for use in clinical practice with individual patients. In particular, there is a need to ensure these are validated for use in clinical settings, acceptable to patients, caregivers and clinicians, and yield meaningful outcomes. © 2014 Primary Care Respiratory Society/Macmillan Publishers Limited

    Abnormal joint torque patterns exhibited by chronic stroke subjects while walking with a prescribed physiological gait pattern

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>It is well documented that individuals with chronic stroke often exhibit considerable gait impairments that significantly impact their quality of life. While stroke subjects often walk asymmetrically, we sought to investigate whether prescribing near normal physiological gait patterns with the use of the Lokomat robotic gait-orthosis could help ameliorate asymmetries in gait, specifically, promote similar ankle, knee, and hip joint torques in both lower extremities. We hypothesized that hemiparetic stroke subjects would demonstrate significant differences in total joint torques in both the frontal and sagittal planes compared to non-disabled subjects despite walking under normal gait kinematic trajectories.</p> <p>Methods</p> <p>A motion analysis system was used to track the kinematic patterns of the pelvis and legs of 10 chronic hemiparetic stroke subjects and 5 age matched controls as they walked in the Lokomat. The subject's legs were attached to the Lokomat using instrumented shank and thigh cuffs while instrumented footlifters were applied to the impaired foot of stroke subjects to aid with foot clearance during swing. With minimal body-weight support, subjects walked at 2.5 km/hr on an instrumented treadmill capable of measuring ground reaction forces. Through a custom inverse dynamics model, the ankle, knee, and hip joint torques were calculated in both the frontal and sagittal planes. A single factor ANOVA was used to investigate differences in joint torques between control, unimpaired, and impaired legs at various points in the gait cycle.</p> <p>Results</p> <p>While the kinematic patterns of the stroke subjects were quite similar to those of the control subjects, the kinetic patterns were very different. During stance phase, the unimpaired limb of stroke subjects produced greater hip extension and knee flexion torques than the control group. At pre-swing, stroke subjects inappropriately extended their impaired knee, while during swing they tended to abduct their impaired leg, both being typical abnormal torque synergy patterns common to stroke gait.</p> <p>Conclusion</p> <p>Despite the Lokomat guiding stroke subjects through physiologically symmetric kinematic gait patterns, abnormal asymmetric joint torque patterns are still generated. These differences from the control group are characteristic of the hip hike and circumduction strategy employed by stroke subjects.</p

    Individual, facility and policy level influences on national coverage estimates for intermittent preventive treatment of malaria in pregnancy in Tanzania

    Get PDF
    BACKGROUND: Delivery of two doses of intermittent preventive treatment of malaria during pregnancy (IPTp) is a key strategy to reduce the burden of malaria in pregnancy in sub-Saharan Africa. However, different settings have reported coverage levels well below the target 80%. Antenatal implementation guidelines in Tanzania recommend IPTp first dose to be given at the second antenatal visit, and second dose at the third visit. This investigation measured coverage of IPTp at national level in Tanzania and examined the role of individual, facility, and policy level influences on achieved coverage. METHODS: Three national household and linked reproductive and child health (RCH) facility surveys were conducted July-August 2005, 2006, and 2007 in 210 clusters sampled using two-stage cluster sampling from 21 randomly selected districts. Female residents who reported a livebirth in the previous year were asked questions about malaria prevention during that pregnancy and individual characteristics including education, pregnancy history, and marital status. The RCH facility serving each cluster was also surveyed, and information collected about drug stocks, health education delivery, and the timing of antenatal care delivery by clinic users. RESULTS: The national IPTp coverage had declined over the survey period being 71% for first dose in 2005 falling to 65% in 2007 (chi2 2.9, p = 0.05), and 38% for second dose in 2005 but 30% in 2007 (chi2 4.4, p = 0.01). There was no evidence of any individual factors being associated with second dose coverage beyond living in an urban area. Availability of sulphadoxine-pyrimethamine at RCH had decreased year on year from 85% of clinics in stock in 2005 to 60% in 2007 (chi2 20.6, p < 0.001). This reduction was evident in rural but not urban clinics. If safety recommendations and national antenatal care guidelines for IPTp delivery were followed, in 2007 only 76% of pregnant women could have received IPTp first dose and only 46% could have received second dose. CONCLUSION: There is scope to improve IPTp first and second dose coverage at national scale within existing systems by improving stock at RCH, and by revising the existing guidelines to recommend delivery of IPTp after quickening, rather than at a pre-defined antenatal visit
    corecore