1,720,957 research outputs found
Serotonergic antidepressant drugs and L-dopa-induced dyskinesias in Parkinson's disease.
No full textBackground – Serotonergic system is believed to play a role in levodopainduced-
dyskinesias pathogenesis, and serotonin transporter has been
evaluated as potential target. Aim of the study – To retrospectively
investigate the potential effect of selective serotonin reuptake inhibitors
(SSRIs) during dopaminergic treatment, in the development of
dyskinesias in patients with Parkinson’s disease (PD). Methods – One
hundred and thirty-five consecutive patients with PD, with 10-year
follow-up since diagnosis. Age at PD onset, duration of levodopa
treatment, maximum daily dose, and SSRIs exposure were collected.
Risk, latency, and severity of dyskinesias were evaluated comparing
patients with and without SSRIs exposure. Results – Forty-nine patients
received SSRIs for a variable period, 86 were never treated; no significant
difference between the groups was observed (P = 0.897) in the prevalence
of dyskinesias. Considering latency between PD diagnosis and
dyskinesias onset, patients exposed to SSRIs developed dyskinesias later
(6.48 1.99 vs 5.70 1.89 years, P = 0.020). The median dyskinesia
severity score was 0 in the exposed group vs 1 in non-exposed patients
(P = 0.025). Multivariate analysis demonstrated SSRIs exposure as the
only independent predictor, protecting from severe dyskinesia.
Conclusions – Use of SSRIs in patients with PD did not protect from
dyskinesias; however, exposure may delay the onset and reduce the
severity, confirming modulation of the serotonergic system as possible
antidyskinetic strateg
Caudate dopaminergic denervation and visual hallucinations: Evidence from a 123I-FP-CIT SPECT study
No full textOBJECTIVE:
The pathogenesis of visual hallucinations (VHs) in Parkinson's disease (PD) has been considered multifactorial. In the pathophysiology of VHs a combination of impaired visual processing and attention has been reported. Imaging studies evidenced a role of the primary visual system and visual association areas as well as a dysfunctional activation of frontal areas in the occurrence of VHs. Due to the functional connections between basal ganglia and frontal areas, a role of basal ganglia and of the fronto-striatal circuits in the pathogenesis of VHs may be postulated. Aim of this study is to unveil whether a presynaptic dopamine deficiency at baseline may predict the development of VHs.
METHODS:
A group of 18 non demented PD patients with VHs was matched with 18 non demented PD patients without VHs as regards age of onset of disease, disease duration and severity and levodopa equivalent dose. We retrospectively analyzed the (123)I-FP CIT SPECT performed on the two groups at the onset of their disease. The striatal uptake values in the two groups were examined, in order to evaluate nigrostriatal differences between the groups with different behavioral phenotype.
RESULTS:
The group of patients with VHs had a significant reduction (p < 0.05) in right caudate uptake values at baseline when compared with patients without VHs. No significant differences were found between the groups regarding left caudate and putaminal uptake values.
CONCLUSIONS:
The frontal impairment reported in PD patients with VHs may be due to a right caudate dysfunction, as it is connected to the frontal brain areas via neuronal loops
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Degree of peripheral thyroxin deiodination, frailty and long-term survival in hospitalized older patients
No full textAlthough the association between low FT3 and poor outcome has been extensively reported in literature, the degree of peripheral thyroxin deiodination and its relationship with frailty and survival in hospitalized older patients has not been fully established yet. The aim of the current study was to evaluate the possible correlation between FT3/FT4 ratio reduction, an indirect marker of thyroxin deiodination impairment, and frailty status and survival in hospitalized older patients
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