1,721,070 research outputs found
Low dimensionality of supraspinally induced force fields
No full textRecent experiments using electrical and N
methyl-D-aspartate microstimulation of the spinal cord gray
matter and cutaneous stimulation of the hindlimb of spinal
ized frogs have provided evidence for a modular organization
of the frog's spinal cord circuitry. A ``module'' is a functional
unit inthespinalcordcircuitrythatgeneratesaspecificmotor
outputbyimposingaspecificpatternofmuscleactivation.The
output of a module can be characterized as a force field: the
collection of the isometric forces generated at the ankle over
different locations in the leg's workspace. Different modules
can be combined independently so that their force fields
linearly sum. The goal of this study was to ascertain whether
the force fields generated by the activation of supraspinal
structures could result from combinations of a small number
of modules. We recorded a set of force fields generated by the
electrical stimulation of the vestibular nerve in seven frogs,
andweperformedaprincipalcomponentanalysistostudythe
dimensionality of this set. We found that 94% of the total
variation of the data is explained by the first five principal
components, a result that indicates that the dimensionality of
the set of fields evoked by vestibular stimulation is low. This
result is compatible with the hypothesis that vestibular fields
are generated by combinations of a small number of spinal
modules
Vasculitis and COVID-19: What do we have to know?
No full textAs the main title 'COVID-19 revolution: a new challenge for the internist' states, the global coronavirus infection disease 2019 (COVID-19) pandemic represented a new challenge for the internists. This paper is part of a series of articles written during the difficult period of the ongoing global pandemic and published all together in this fourth issue of the Italian Journal of Medicine, with the aim of sharing the direct experiences of those who were the first to face this severe emergency, expressing each point of view in the management of COVID-19 in relation to other diseases. Each article is therefore the result of many efforts and a joint collaboration between many colleagues from the Departments of Internal Medicine or Emergency Medicine of several Italian hospitals, engaged in the front line during the pandemic. These preliminary studies therefore cover diagnostic tools available to health care personnel, epidemiological reflections, possible new therapeutic approaches, discharge and reintegration procedures to daily life, the involvement of the disease not only in the lung, aspects related to various comorbidities, such as: coagulopathies, vasculitis, vitamin D deficiency, gender differences, etc.. The goal is to offer a perspective, as broad as possible, of everything that has been done to initially face the pandemic in its first phase and provide the tools for an increasingly better approach, in the hope of not arriving unprepared to a possible second wave. This paper in particular deals with vasculitis and COVID-19
Representation in Natural and Artificial Systems
No full textKönig P, Bizzi E, Burgess N, et al. Representation in Natural and Artificial Systems. Zeitschrift für Naturforschung. C, a Journal of Biosciences. 1998;53(7-8):738-751
Mixed-treatment comparison of anabolic (teriparatide and PTH 1-84) therapies in women with severe osteoporosis
No full textPurpose: The recent development of compounds with anabolic action on bone have increased the range of therapeutic options for the treatment of osteoporosis and the prevention of fractures. Two major PTH analogs, the synthetic full-length 1-84 PTH molecule and the recombinant 1-34 N-terminal fragment (teriparatide), are available for the treatment of osteoporosis in many countries. There have bee no comparative trials on the bone anabolic effects of these compounds. Materials and methods: In this study we applied a mixed treatment comparison (MTC) to compare the efficacy of teriparatide versus PTH 1-84 for the prevention of vertebral and non-vertebral fractures in women with severe osteoporosis. With this approach the relative treatment effect of one intervention over another can be obtained in the absence of head-to-head comparison. Among the candidate papers selected for analysis, two randomized controlled trials investigating the effects of teriparatide and PTH 1-84 met the selection criteria and underwent MTC analysis. Results: Based on a fixed-effect MTC model analysis of data from two RCTs, teriparatide (20g/day) showed a 70% and 94% probability of being the best treatment for the prevention of vertebral and non-vertebral fractures, respectively. Together with a lack of statistical significance, this study has additional limitations. Some differences in trial procedures and populations exist; another limitation concerns the impossibility of carrying out a randomized-effect model MTC, due to sample exiguity. Furthermore, in order to consider unknown or unmeasured differences of covariates across trials, a random-effects approach would be preferred in order to assess the presence of heterogeneity across comparisons. In contrast, in our analysis a fixed-effect MTC model only was used. Conclusions: Teriparatide is expected to provide a greater efficacy over PTH 1-84 with both vertebral and non-vertebral fracture prevention in postmenopausal women with severe osteoporosis. © 2012 Informa UK Ltd All rights reserved
A theory for how sensorimotor skills are learned and retained in noisy and nonstationary neural circuits
No full textIs it the time to rethink clinical decision-making strategies? From a single clinical outcome evaluation to a Clinical Multi-criteria Decision Assessment (CMDA)
No full textThere are plenty of different clinical, organizational and economic parameters to consider in order having a complete assessment of the total impact of a pharmaceutical treatment. In the attempt to follow, a holistic approach aimed to provide an evaluation embracing all clinical parameters in order to choose the best treatments, it is necessary to compare and weight multiple criteria. Therefore, a change is required: we need to move from a decision-making context based on the assessment of one single criteria towards a transparent and systematic framework enabling decision makers to assess all relevant parameters simultaneously in order to choose the best treatment to use. In order to apply the MCDA methodology to clinical decision making the best pharmaceutical treatment (or medical devices) to use to treat a specific pathology, we suggest a specific application of the Multiple Criteria Decision Analysis for the purpose, like a Clinical Multi-criteria Decision Assessment CMDA. In CMDA, results from both meta-analysis and observational studies are used by a clinical consensus after attributing weights to specific domains and related parameters. The decision will result from a related comparison of all consequences (i.e., efficacy, safety, adherence, administration route) existing behind the choice to use a specific pharmacological treatment. The match will yield a score (in absolute value) that link each parameter with a specific intervention, and then a final score for each treatment. The higher is the final score; the most appropriate is the intervention to treat disease considering all criteria (domain an parameters). The results will allow the physician to evaluate the best clinical treatment for his patients considering at the same time all relevant criteria such as clinical effectiveness for all parameters and administration route. The use of CMDA model will yield a clear and complete indication of the best pharmaceutical treatment to use for patients, helping physicians to choose drugs with a complete set of information, imputed in the model
Indirect comparison of etanercept, infliximab, and adalimumab for psoriatic arthritis: mixed treatment comparison using placebo as common comparator
No full textPsoriatic arthritis (PsA) is a chronic inflammatory joint disorder that is commonly associated with skin psoriatic lesions and can lead to severe disability. Current pharmacologic therapy for PsA includes TNFα-blocking agents for patients who are intolerant of or have an inadequate response to conventional disease-modifying antirheumatic drugs. Currently, there are no published randomized controlled trials providing a head-to-head comparison of the effectiveness of the three TNFα-blocking agents used most often to treat patients with PsA (adalimumab, etanercept, and infliximab). In this study, we have performed the first indirect comparison among these biologic agents, in this setting, using a mixed treatment comparison analysis of the data from pivotal trials regarding efficacy profiles of adalimumab, etanercept, and infliximab evaluated as American College of Rheumatology (ACR) 20 response. Our results suggest that etanercept is expected to provide the greatest ACR20 response among the anti-TNFα agents compared with placebo in the treatment of patients with PsA unresponsive to conventional treatments. This analysis may be relevant for clinical decision-making, hence improving the management of PsA patients
Mechanisms underlying recovery of eye-head coordination following bilateral labyrinthectomy in monkeys
No full textEfficacy of biological agents administered as monotherapy in rheumatoid arthritis: a Bayesian mixed-treatment comparison analysis
No full textBackground: Biological agents provide an important therapeutic alternative for rheumatoid arthritis patients refractory to conventional disease-modifying antirheumatic drugs. Few head-to-head comparative trials are available. Purpose: The aim of this meta-analysis was to compare the relative efficacy of different biologic agents indicated for use as monotherapy in rheumatoid arthritis. Methods: A systemic literature search was performed on electronic databases to identify articles reporting double-blind randomized controlled trials investigating the efficacy of biologic agents indicated for monotherapy. Efficacy was assessed using American College of Rheumatology (ACR) 20, 50, and 70 criteria at 16–24 weeks. Relative efficacy was estimated using Bayesian mixed-treatment comparison models. Outcome measures were expressed as odds ratio and 95% credible intervals. Results: Ten randomized controlled trials were selected for data extraction and analysis. Mixed-treatment comparison analysis revealed that tocilizumab offered 100% probability of being the best treatment for inducing an ACR20 response versus placebo, methotrexate, adalimumab, or etanercept. Likewise, for ACR50 and ACR70 outcome responses, tocilizumab had a 99.8% or 98.7% probability of being the best treatment, respectively, compared to other treatments or placebo. Tocilizumab increased the relative probability of being the best treatment (vs methotrexate) by 3.2-fold (odds ratio: 2.1–3.89) for all ACR outcomes. Conclusion: Tocilizumab offered the greatest possibility of obtaining an ACR20, ACR50, and ACR70 outcome vs other monotherapies or placebo
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