1,721,219 research outputs found
Exploring the Role of Locus Coeruleus in Alzheimer's Disease: a Comprehensive Update on MRI Studies and Implications
No full textPurpose of review: Performing a thorough review of magnetic resonance imaging (MRI) studies assessing locus coeruleus (LC) integrity in ageing and Alzheimer's disease (AD), and contextualizing them with current preclinical and neuropathological literature. Recent findings: MRI successfully detected LC alterations in ageing and AD, identifying degenerative phenomena involving this nucleus even in the prodromal stages of the disorder. The degree of LC disruption was also associated with the severity of AD cortical pathology, cognitive and behavioral impairment, and the risk of clinical progression. Locus coeruleus-MRI has proved to be a useful tool to assess the integrity of the central noradrenergic system in vivo in humans. It allowed to test in patients preclinical and experimental hypothesis, thus confirming the specific and marked involvement of the LC in AD and its key pathogenetic role. Locus coeruleus-MRI-related data might represent the theoretical basis on which to start developing noradrenergic drugs to target AD
The placebo and nocebo responses in patients with epilepsy
No full textPlacebo and nocebo responses in epilepsy have been mainlyinvestigated by meta-analytic approaches aimed to evaluate the extent ofsuch phenomenon in randomized, controlled, clinical trials. These studiesreported placebo response rates (defined as proportion of patients with =50% improvement of seizures compared to baseline observations) rangingfrom 9.9% up to 15.2%. The proportion of patients with adverse events(AEs) and those withdrawing because of intolerable AEs, as index ofnocebo response, were 60.3% and 3.9%, respectively. Moreover, a fullevaluation of specific AEs reported by patients receiving placebo hasbeen performed. A number of factors related to the features of patients(severity of disease), to the study design, or to non-specific factors (suchas year of publication and geographic area), as well as to positive ornegative expectations of patients, caregivers and experimenters have beenshowed to influence placebo and nocebo response in epilepsy. Acharacterization of these factors is crucial for a better interpretation ofstudy results and to improve design of new clinical trials. All recent datawill be presented and discussed in detail.In addition, as neurobiological studies in epilepsy are lacking,putative mechanisms of placebo and nocebo responses in epilepsy will behypothesized and discussed along with possible consequences in clinicalpractic
Editorial: Epilepsy in older adults: From physiopathology to improvements in diagnosis and management
No full textAlpha-Synuclein Toxicity: An Insight on Controversial Issues
No full textα-Synuclein (α-syn) is a major constituent of neuronal inclusions known as Lewy bodies (LBs), which typically occur in Parkinson’s disease (PD) and “synucleinopathies.” Accumulation of α-syn aggregates occurs also in additional disorders, forming inclusions which may also feature aggregates of abnormal Tau protein. The hypothesis that accumulation of α-syn is key for neurodegeneration is grounded on familial forms of PD due to a specific mutation of α-syn or a duplication of the gene with abnormally high level of normally conformed α-syn. Thus, α-syn has been proposed to act as an endogenous neurotoxin. In this chapter, a detailed description of α-syn at synaptic level is provided. Then, the mechanisms and conditions through which α-syn might bear a detrimental role are extensively discussed, in particular, in neurological disorders and experimental models of neurodegeneration. In the last decades, several data have shown that overexpressed α-syn behaves as a neurotoxin through a variety of mechanisms; these include an impairment of cell-clearing system, a self-perpetuating fibrillization, a prion-like spreading from an area to another one, and also profiting of axonal transport. In particular, the mechanisms which regulate the clearance of α-syn such as the proteasome and autophagy, are discussed in relationship with an abnormal α-syn accumulation. In search not to cut any corner of such a complex issue, the beneficial effects of α-syn are described as well; among these is the neuroprotective effect to counteract methamphetamine-induced dopaminergic toxicity, which is bound to an antiapoptotic chaperone-like role
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Epilepsy and other neurological disorders
No full textNeurological disorders constitute the etiological factors of symptomatic epilepsies. However, in recent times, there are evidences that there is a mutual strong interaction between epilepsy and other diseases of the central nervous system and that in some cases these may be caused by a hidden etiologic factor that has been called “systemic dysfunction.” Furthermore, in all cases epilepsy and comorbid neurologic diseases influence each other through several mechanisms, including drug treatments. The consequence of this approach is that treatment strategy should consider, at the same time, all diseases that affect brain function. Epilepsy and cerebrovascular diseases are frequently associated, and the interaction between these diseases affect prognosis. Choice of treatments is of strategic importance. For example, there are antiepileptic drugs that may worsen vascular disease and negatively interact with drugs used for vascular disorder. This applies also to comorbidity with infectious diseases, brain tumors, and several neurodegenerative diseases
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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