1,720,961 research outputs found
Association study between the phenotype migraine without aura-panic disorder and dopaminergic receptor genes
No full textClinical and epidemiological evidence suggests that migraine often co-occurs with psychopathological conditions. Several longitudinal and population-based studies have suggested that migraine and panic disorder might share a common predisposition. An abnormal dopaminergic function has been hypothesized to be involved as etiological factor in panic disorder as well as in migraine. Epidemiological and molecular data suggest the role of genetic factors in the pathogenesis of both migraine and panic attack disorder. We assessed the presence of panic disorder in 100 probands suffering from migraine without aura and the present study was designed to analyse the possible association of the migraine-panic phenotype with dopaminergic genes. In our sample, 17 out of 100 migraineurs were affected by panic disorder and were thus considered for the genetic association study. The allele frequencies of DRD1, DRD3, DRD5, DRD2 in probands did not differ from that of parental non-transmitted chromosomes. This result does not seem to support, in our limited sample, a common pathological basis, with regard to the dopaminergic system, between migraine and panic. Should migraine and panic disorder share some common mechanisms, these could be sought in neuro-chemical systems other than the dopaminergic one
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
Migraine and Tumor Necrosis Factor gene polymorphism: an association study in a sardinian sample
No full textVariations 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
Evaluation of lithium response in episodic cluster headache: a retrospective case series
No full textObjective.- In this study, we attempted to evaluate the response to lithium treatment and its tolerability in the prevention of episodic cluster headache (CH) and to identify clinical predictors of response. Background.- Verapamil and lithium are the most widely used drugs in the prevention of CH attacks. Lithium is considered a second-line treatment in part because of its potentially severe adverse drug reactions (ADRs). Evidence for the efficacy of lithium in CH prevention is greater in chronic than in episodic patients. In addition, because of its narrow therapeutic window and ADRs (which can be significantly reduced with proper periodical monitoring of blood levels), lithium is recommended only in chronic CH, when other drugs are ineffective or potentially harmful. Methods.- Our primary aim was to determine whether lithium reduced the number of attacks per day (attack frequency). We compared attack frequency in 3 periods: run-in, the first, and the second week of lithium treatment. Responders were defined as patients showing at least a 50% reduction in attack frequency. Results.- Lithium response was evaluated in 26 patients. Treatment led to a significant reduction in attack frequency within 2 weeks in a percentage of 77% of responders and 23% of nonresponders. Responders and nonresponders did not differ in terms of demographic and clinical characteristics. Only 15% of patients experienced mild ADRs. Conclusion.- Our study provides additional evidence on the effectiveness of lithium in the prevention of episodic CH. It also shows the tolerability of lithium, given the short duration of treatment and low dosage
Mixture analysis of age at onset in migraine without aura: evidence for three subgroups
No full textOBJECTIVE: To verify the presence of different age at onset (AAO) subgroups of patients in a sample of patients with migraine without aura (MWA) and compare clinical correlates among them.
BACKGROUND: MWA is a long-lasting disease whose prognosis has not yet been fully investigated. Patients may present complete remission, partial clinical remission, persistence and progression (migraine attack frequency and disability may increase over time leading to chronic migraine). Limited evidence exists regarding the identification of risk factors or predictors which might influence migraine prognosis. AAO has been proven a useful tool in the investigation of the clinical, biological, and genetic characteristics able to influence the prognosis of a number of neuropsychiatric disorders. AAO distribution was studied using mixture analysis, a statistical approach that breaks down the empirical AAO distribution observed into a mixture of normal components.
METHODS: A sample of 334 outpatients affected by MWA, recruited in a clinical genetic study at our Headache Center from 2004 to 2008, was enrolled for this study. Diagnosis was made according to International Headache Society criteria 2004. AAO distribution in patients was studied using mixture analysis. Chi-square test was used to compare clinical correlates among identified subgroups. Logistic regression was performed in order to correct for effect of possible confounders.
RESULTS: Mixture analysis broke up the observed distribution of AAO into 3 normal theoretical distributions. Informational criteria clearly showed a better 3-component model rather than the 2-component one. An early-onset (≤ 7 years of age), an intermediate-onset (≥ 8 and ≤ 22), and a late-onset group (≥ 23) were identified. Comparison of clinical correlates among subgroups by means of chi-square test showed a statistically significant result for migraine frequency (χ(2) = 7.41, P = .02). Considering the frequency of migraine attacks as a main outcome, the regression model showed a higher AAO is associated with low frequency (odds ratio =0.95; P= .02).
CONCLUSIONS: The significant association between AAO and attack frequency found in our study supports the hypothesis that AAO could act as a predictor factor able to influence prognosis. AAO could represent a phenotype suitable for identifying MWA susceptibility genes
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
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