3,122 research outputs found

    Rizatriptan versus rizatriptan plus rofecoxib versus rizatriptan plus tolfenamic acid in the acute treatment of migraine

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    BACKGROUND: Rizatriptan is an effective and fast acting drug for the acute treatment of migraine. Some nonsteroidal anti-inflammatory drugs (NSAID) have also demonstrated efficacy in treating migraine attacks. There is evidence that the combination of a triptan and a NSAID decreases migraine recurrence in clinical practice. The primary aim of this randomized open label study was to assess the recurrence rates in migraine sufferers acutely treated with rizatriptan (RI) alone vs. rizatriptan plus a COX-2 enzyme inhibitor (rofecoxib, RO) vs. rizatriptan plus a traditional NSAID (tolfenamic acid, TO). We were also interested in comparing the efficacy rates within these three groups. METHODS: We assessed 45 patients from a headache clinic in Rio de Janeiro (35 women and 10 men, ages 18 to 65 years, mean 37 years). Patients with IHS migraine were randomized to one out of 3 groups, where they had to treat 6 consecutive moderate or severe attacks in counterbalanced order. In group 1, patients treated the first two attacks with 10 mg RI, the third and fourth attacks with RI + 50 mg RO and the last attacks with RI + 200 mg of TA. In group 2, we began with RI + TA, followed by RI, and RI + RO. Group 3 treated in the following order: RI + RO, RI + TA, RI alone. The presence of headache, nausea and photophobia at 1, 2 and 4 hours, as well as recurrence and side effects were compared. RESULTS: A total of 33 patients finished the study, treating 184 attacks. The pain-free rates at 1 hour were: RI: 15.5%; RI + RO: 22.6%; RI + TA: 20.3%(NS). Pain-free rates at 2 h were: RI: 37.9%; RI + RO: 62.9%, and RI + TA: 40.6% (p = 0.008 for RI vs. RI + RO; p = 0.007 for RI + RO vs. RI + TA, NS for RI vs RI + TA). At 4 h, pain-free rates were: RI: 69%; RI + RO: 82.3%; RI + TA: 78.1% (NS for all comparisons). The combination of RI + RO was superior to RI and to RI + TA in regard of the absense of nausea and photophobia at 4 hours. Recurrence (after being pain-free at 2 h) was observed in 50% of patients treated with RI, in 15,4% of those treated with RI + RO, and in 7,7% of those treated with RI + TA. CONCLUSIONS: Despite the methodological limitations of this study, the combination of RI and RO revealed a higher response rate at 2 hours. Recurrence was also clearly decreased with both combinations in relation to the use of RI alone. Controlled studies are necessary to provide additional evidence

    Acute treatment of migraine. Breaking the paradigm of monotherapy

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    BACKGROUND: Migraine is a highly prevalent disorder. The disability provoked by its attacks results in suffering as well as considerable economic and social losses. The objective of migraine acute treatment is to restore the patient to normal function as quickly and consistently as possible. There are numerous drugs available for this purpose and despite recent advances in the understanding of the mechanisms and different biological systems involved in migraine attacks, with the development of specific 5-HT agonists known as triptans, current options for acute migraine still stand below the ideal. DISCUSSION: Monotherapeutic approaches are the rule but up to one third of all patients discontinue their medications due to lack of efficacy, headache recurrence, cost and/or side effects. In addition, a rationale has been suggested for the development of polytherapeutic approaches, simultaneously aiming at some of the biological systems involved. This paper reviews the fundamentals for this changing approach as well as the evidence of its better efficacy. CONCLUSION: As a conclusion, most of the patients with a past history of not responding (no pain-free at 2 hours and/or no sustained pain-free at 24 hours) in at least 5 previous attacks should undergo a combination therapy suiting to their individual profile, which must include analgesics or non-steroidal anti-inflammatory agents plus a triptan or a gastro kinetic drug. The three-drug regimen may also be considered. In addition, changing the right moment to take it and the choice for formulations other than oral has also to be determined individually and clearly posted to the patient

    Dynamic walking features and improved walking performance in multiple sclerosis patients treated with fampridine (4-aminopyridine)

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    Background: Impaired walking capacity is a frequent confinement in Multiple Sclerosis (MS). Patients are affected by limitations in coordination, walking speed and the distance they may cover. Also abnormal dynamic walking patterns have been reported, involving continuous deceleration over time. Fampridine (4-aminopyridine), a potassium channel blocker, may improve walking in MS. The objective of the current study was to comprehensively examine dynamic walking characteristics and improved walking capacity in MS patients treated with fampridine. Methods: A sample of N = 35 MS patients (EDSS median: 4) underwent an electronic walking examination prior to (Time 1), and during treatment with fampridine (Time 2). Patients walked back and forth a distance of 25 ft for a maximum period of 6 min (6-minute 25-foot-walk). Besides the total distance covered, average speed on the 25-foot distance and on turns was determined separately for each test minute, at Time 1 and Time 2. Results: Prior to fampridine administration, 27/35 patients (77 %) were able to complete the entire 6 min of walking, while following the administration, 34/35 patients (97 %) managed to walk for 6 min. In this context, walking distance considerably increased and treatment was associated with faster walking and turning across all six test minutes (range of effect sizes: partial eta squared = .34-.72). Importantly, previously reported deceleration across test minutes was consistently observable at Time 1 and Time 2. Discussion: Fampridine administration is associated with improved walking speed and endurance. Regardless of a treatment effect of fampridine, the previously identified, abnormal dynamic walking feature, i.e. the linear decline in walking speed, may represent a robust feature. Conclusions: The dynamic walking feature might hence be considered as a candidate for a new outcome measure in clinical studies involving interventions other than symptomatic treatment, such as immune-modulating medication. Trial registration: DRKS00009228 (German Clinical Trials Register). Date obtained: 25.08.2015

    Cascaded two-photon nonlinearity in a one-dimensional waveguide with multiple two-level emitters

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    We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation).Comment: 6 pages, 4 figure

    The population of close double white dwarfs in the Galaxy

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    We present a new model for the Galactic population of close double white dwarfs. The model accounts for the suggestion of the avoidance of a substantial spiral-in during mass transfer between a giant and a main-sequence star of comparable mass and for detailed cooling models. It agrees well with the observations of the local sample of white dwarfs if the initial binary fraction is close to 50% and an ad hoc assumption is made that white dwarfs with mass less than about 0.3 solar mass cool faster than the models suggest. About 1000 white dwarfs brighter than V=15 have to be surveyed for detection of a pair which has total mass greater than the Chandrasekhar mass and will merge within 10 Gyr.Comment: 15 pages, 7 figures, to appear in Proc. ``The influence of binaries on stellar population studies'', Brussels, August 2000 (Kluwer, D. Vanbeveren ed.

    GRANADA consensus on analytical approaches to assess associations with accelerometer-determined physical behaviours (physical activity, sedentary behaviour and sleep) in epidemiological studies.

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    The inter-relationship between physical activity, sedentary behaviour and sleep (collectively defined as physical behaviours) is of interest to researchers from different fields. Each of these physical behaviours has been investigated in epidemiological studies, yet their codependency and interactions need to be further explored and accounted for in data analysis. Modern accelerometers capture continuous movement through the day, which presents the challenge of how to best use the richness of these data. In recent years, analytical approaches first applied in other scientific fields have been applied to physical behaviour epidemiology (eg, isotemporal substitution models, compositional data analysis, multivariate pattern analysis, functional data analysis and machine learning). A comprehensive description, discussion, and consensus on the strengths and limitations of these analytical approaches will help researchers decide which approach to use in different situations. In this context, a scientific workshop and meeting were held in Granada to discuss: (1) analytical approaches currently used in the scientific literature on physical behaviour, highlighting strengths and limitations, providing practical recommendations on their use and including a decision tree for assisting researchers' decision-making; and (2) current gaps and future research directions around the analysis and use of accelerometer data. Advances in analytical approaches to accelerometer-determined physical behaviours in epidemiological studies are expected to influence the interpretation of current and future evidence, and ultimately impact on future physical behaviour guidelines

    A model for reactive porous transport during re-wetting of hardened concrete

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    A mathematical model is developed that captures the transport of liquid water in hardened concrete, as well as the chemical reactions that occur between the imbibed water and the residual calcium silicate compounds residing in the porous concrete matrix. The main hypothesis in this model is that the reaction product -- calcium silicate hydrate gel -- clogs the pores within the concrete thereby hindering water transport. Numerical simulations are employed to determine the sensitivity of the model solution to changes in various physical parameters, and compare to experimental results available in the literature.Comment: 30 page

    Dorsolateral medullary ischemic infarction causing autonomic dysfunction and headache: a case report

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    Stroke can present, among other signs, with headache. Here, we describe the case of a man suffering from severe orbitary pain and autonomic dysfunction secondary to dorsolateral medullary ischemia. The anatomical relationship between lesion and symptomatology could be an indirect sign of hypothalamospinal tract involvement in the genesis of autonomic dysfunction and headache resembling a trigeminal autonomic cephalalgia

    Building nonparametric nn-body force fields using Gaussian process regression

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    Constructing a classical potential suited to simulate a given atomic system is a remarkably difficult task. This chapter presents a framework under which this problem can be tackled, based on the Bayesian construction of nonparametric force fields of a given order using Gaussian process (GP) priors. The formalism of GP regression is first reviewed, particularly in relation to its application in learning local atomic energies and forces. For accurate regression it is fundamental to incorporate prior knowledge into the GP kernel function. To this end, this chapter details how properties of smoothness, invariance and interaction order of a force field can be encoded into corresponding kernel properties. A range of kernels is then proposed, possessing all the required properties and an adjustable parameter nn governing the interaction order modelled. The order nn best suited to describe a given system can be found automatically within the Bayesian framework by maximisation of the marginal likelihood. The procedure is first tested on a toy model of known interaction and later applied to two real materials described at the DFT level of accuracy. The models automatically selected for the two materials were found to be in agreement with physical intuition. More in general, it was found that lower order (simpler) models should be chosen when the data are not sufficient to resolve more complex interactions. Low nn GPs can be further sped up by orders of magnitude by constructing the corresponding tabulated force field, here named "MFF".Comment: 31 pages, 11 figures, book chapte
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