1,720,963 research outputs found
Proposal of changing subtype 8.1 "Headache induced by acute substance use or exposure" and subtype 8.3 "Headache as an adverse event attributed to chronic medication" of ICHD-II
No full textHeadaches as adverse reactions and symptom of intoxication, are included in subtype 8.1 of ICHD-II, even if, for example, headache induced by phosphodiesterase inhibitors has a completely different pathogenesis from headache induced by carbon monoxide or by cocaine. We propose a revision of subtypes 8.1 and 8.3, so that the classification could be used in clinical setting to diagnostic and therapeutic aims.
In literature, adverse reactions are divided into two types: pharmacological (type A) and non-pharmacological ones (types B). Adverse reactions of type A are an extension of the main pharmacological action of the drug and are induced by an increase in pharmacological activities (A=augmented). They are frequent, foreseeable, dose-dependent, with high morbidity, but practically non-existent mortality, and can be already detected in the pre-clinical phase of the study of the drug. Non-pharmacological adverse reactions are not related to the main pharmacological action, they are an unusual and/or unexpected effect of the medication (B=bizarre), rare and unforeseeable, they have very low morbidity, but they can be mortal, and they often only appear after prolonged treatments. However, headaches as adverse reactions which are not induced by an increase in the main pharmacological activity of the drug (i.e., which cannot be classified as type A) do not belong to type B, since they can be frequent, but never rare or mortal, and they often also appear after prolonged treatments. This is the case of headaches induced by antimicrobials, antiviral agents, interferons, corticosteroids, and H2 receptor antagonists. These headaches are probably caused by factors such as benign intracranial hypertension, flu-like syndrome, or aseptic meningitis. We only define these adverse reactions as non-A-non-B in order to easily indicate them. We propose to classify the headaches of subtypes 8.1 and 8.3 into 4 subforms: 1. headaches induced by drugs which can also worsen a pre-existent headache; they are divided into two subgroups, depending on the pathogenesis of the headache as an adverse reaction (- type A; - type non-A-non-B); 2. food additive-induced headaches; 3. acute or chronic intoxication-induced headaches; 4. exogenous hormone-induced headache. We propose that food-induced headaches should be moved to the appendix, to indicate that further evidence is needed to prove their real existence. In particular, we need to increase the number of clinical case histories with objective instead of anecdotal data, in order to decide whether they are a clinical reality or rare to the point of being unique cases
Plasma concentrations of glutamate in patients suffering from chronic migraine overusing acute medication, before and after withdrawal treatment
No full textA dysfunction of the glutamatergic system would have an essential role in the pathogenetic mechanism of the migraine. Glutamate is implicated in cortical spreading depression, trigeminovascular activation, and central sensitization [1]. Higher glutamate levels than those of healthy controls have been reported in migraine patients’ plasma and platelets [2] and in chronic migraine patients’ cerebrospinal fluid [3].
Our aim was verifying if there were differences in the plasma levels of glutamate between patients with chronic migraine overusing acute medications and control subjects, and if plasma levels of glutamate in chronic migraine patients modified after withdrawal from the overused medication.
Methods. We studied 12 patients (F=10, M=2; mean age 50.3±9.8 years) with diagnosis of chronic migraine, according to ICHD-II criteria, overusing acute medications, and 15 healthy subjects as controls (F=2, M=3; mean age 48.2±7.3 years). Patients were studied twice, before and after 15 days of standardized inpatient withdrawal treatment. Venous blood samples for the assay of glutamate concentrations were taken in the morning, after overnight fasting. Glutamate concentrations were measured by means of a fluorimetric detector high pressure liquid chromatographic (HPLC/FD) method.
Results. Plasma concentrations of glutamate were significantly higher in chronic migraine patients either before (62.5±5.1 μmol/L) or after treatment (27.7±11.3 μmol/L) than in control subjects (7.3±2.9 μmol/L) (P<0.05, ANOVA followed by Student-Newman-Keuls’ test). However, after 15 days of inpatient withdrawal treatment, once overuse was interrupted, and the frequency of headache reduced, plasma glutamate concentrations were significantly lower in the same patient with respect to the prior level (P<0.0001, Student’s t-test for paired data), without any differences depending on the kind of medication overused.
Conclusions. Elevated plasma levels of glutamate in chronic migraine sufferers could support the role of this excitatory aminoacid in the process of central sensitization. The decline in glutamate plasma concentrations is associated with medication-overuse discontinuation and reduced headache frequency; thus, plasma glutamate levels monitoring in chronic migraine might serve as a biomarker of clinical improvement.
[1] Ramadan NM. The link between glutamate and migraine. CNS Spectr 2003; 8(6):446-9
[2] Alam Z, Coombes N, Waring RH, Williams AC, Steventon GB. Plasma levels of neuroexcitatory amino acids in patients with migraine or tension headache. J Neurol Sci 1998; 156(1):102-6
[3] Peres MF, Zukerman E, Senne Soares CA, Alonso EO, Santos BF, Faulhaber MH. Cerebrospinal fluid glutamate levels in chronic migraine. Cephalalgia 2004; 24(9):735-
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
The GHB-analogue, GET 73, prevents either the development of preference for sucrose in non-stressed rats, or the reduction of sucrose intake in chronically stressed rats
No full textRats treated with GET 73 do not develop the "depression-like" condition produced by the daily exposure, for several weeks, to continuously and unpredictably varied stressful situations, in one of the most valid "depression" models
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
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