205 research outputs found

    Natalizumab therapy, 2013

    Get PDF
    Multiple sclerosis (MS) is the most common chronic disease of the central nervous system in young adults. No curative therapy is known. Currently, six drugs are available that can reduce the activity of MS. The first-line drugs can completely reduce the activity of the disease in nearly two-thirds of the patients. In the remainder, who suffer from breakthrough disease, the condition of the patient worsens, and second-line therapies must be used. The second-line drug natalizumab exhibits almost double efficacy of the first-line drugs, but also have less favourable adverse effects. As a severe side-effect for instance, natalizumab carries the risk of the development of progressive multifocal leucoencephalopathy (PML), caused by a polyoma virus, the JC virus. There are three major risk factors for PML: an anti-JCV antibody status, a long duration of natalizumab treatment and prior immunosuppressant therapy. The lowest-risk group (1:14 286) comprises of patients who are anti-JCV antibody-negative, in whom the prior immunosuppressant use and duration of natalizumab therapy do not influence the risk of PML. With no prior immunosuppressant treatment, the incidence of PML increases to 1 in 192 patients after 2 years among those who are anti-JCV antibody-positive. These data may lead the physician to decide to discontinue natalizumab treatment. The half-life of natalizumab is three months; during this time other therapies can not be administered and the patients encounter the rebound effect: as the patients receiving natalizumab therapy displayed a high disease activity before treatment, the rebound effect can lead to relapses. After the termination of natalizumab second-line disease-modifying therapy with fingolimod may be introduce; no PML cases occur in response to fingolimod treatment. In the large majority of patients taking natalizumab who do not develop PML, this drug is highly effective and can prevent the progression of MS. The benefit of therapy and the risk of PML must be considered on an individual basis, with regard to the disease activity, the progression and the MRI activity, before natalizumab therapy is implemented

    Optimisation of a machine learning algorithm in human locomotion using principal component and discriminant function analyses

    Get PDF
    Assessment methods in human locomotion often involve the description of normalised graphical profiles and/or the extraction of discrete variables. Whilst useful, these approaches may not represent the full complexity of gait data. Multivariate statistical methods, such as Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA), have been adopted since they have the potential to overcome these data handling issues. The aim of the current study was to develop and optimise a specific machine learning algorithm for processing human locomotion data. Twenty participants ran at a self-selected speed across a 15m runway in barefoot and shod conditions. Ground reaction forces (BW) and kinematics were measured at 1000 Hz and 100 Hz, respectively from which joint angles (°), joint moments (N.m.kg-1) and joint powers (W.kg-1) for the hip, knee and ankle joints were calculated in all three anatomical planes. Using PCA and DFA, power spectra of the kinematic and kinetic variables were used as a training database for the development of a machine learning algorithm. All possible combinations of 10 out of 20 participants were explored to find the iteration of individuals that would optimise the machine learning algorithm. The results showed that the algorithm was able to successfully predict whether a participant ran shod or barefoot in 93.5% of cases. To the authors’ knowledge, this is the first study to optimise the development of a machine learning algorithm

    Robust spatially resolved pressure measurements using MRI with novel buoyant advection-free preparations of stable microbubbles in polysaccharide gels

    Get PDF
    MRI of fluids containing lipid coated microbubbles has been shown to be an effective tool for measuring the local fluid pressure. However, the intrinsically buoyant nature of these microbubbles precludes lengthy measurements due to their vertical migration under gravity and pressure-induced coalescence. A novel preparation is presented which is shown to minimize both these effects for at least 25 min. By using a 2% polysaccharide gel base with a small concentration of glycerol and 1,2-distearoyl-sn-glycero-3-phosphocholine coated gas microbubbles, MR measurements are made for pressures between 0.95 and 1.44 bar. The signal drifts due to migration and amalgamation are shown to be minimized for such an experiment whilst yielding very high NMR sensitivities up to 38% signal change per bar

    Honey bee vibration monitoring using the 805M1 accelerometer

    Get PDF
    In this work we demonstrate that the 805M1 single axis analogue output accelerometer can be used to monitor honey bee activity and requires only a low cost microcontroller with an audio shield to log the data. We present accelerometer output signals demonstrating the ability to capture individual honey bee ‘whooping’ signals as well as long term amplitude monitoring, indicating the brood cycle, using this affordable measurement system

    Possible Case of Maternal Transmission of Feline Spongiform Encephalopathy in a Captive Cheetah

    Get PDF
    Feline spongiform encephalopathy (FSE) is considered to be related to bovine spongiform encephalopathy (BSE) and has been reported in domestic cats as well as in captive wild cats including cheetahs, first in the United Kingdom (UK) and then in other European countries. In France, several cases were described in cheetahs either imported from UK or born in France. Here we report details of two other FSE cases in captive cheetah including a 2nd case of FSE in a cheetah born in France, most likely due to maternal transmission. Complete prion protein immunohistochemical study on both brains and peripheral organs showed the close likeness between the two cases. In addition, transmission studies to the TgOvPrP4 mouse line were also performed, for comparison with the transmission of cattle BSE. The TgOvPrP4 mouse brains infected with cattle BSE and cheetah FSE revealed similar vacuolar lesion profiles, PrPd brain mapping with occurrence of typical florid plaques. Collectively, these data indicate that they harbor the same strain of agent as the cattle BSE agent. This new observation may have some impact on our knowledge of vertical transmission of BSE agent-linked TSEs such as in housecat FSE, or vCJD
    • 

    corecore