1,720,962 research outputs found
Pharmacokinetics of indomethacin in chronic migraine patients after withdrawal of the overused combination of indomethacin, prochlorperazine, and caffeine
No full textThe combination of indomethacin, prochlorperazine and caffeine (IPC) is often overused by migraine patients who develop medication-overuse headache (MOH), a secondary chronic headache that resolves after withdrawal of the overused medication. In a previous study (1) we showed that indomethacin clearance was lower in chronic migraine patients overusing IPC combination than in migraine patients only occasionally taking this combination. Objective: To verify if the reduced clearance of indomethacin reverts to normal after withdrawal of the overused IPC. Methods: We repeated the study of indomethacin pharmacokinetics in 9 female headache patients after 6 months from inpatient withdrawal of the IPC combination. In each patients indomethacin pharmacokinetics had been already studied before withdrawal treatment. The IPC combination (indomethacin 50 mg, prochlorperazine 8 mg, caffeine150 mg) habitually taken was administered by rectal route to each patient. Blood samples were drawn before dosing and at the following post-dose times: 0.5, 1, 2, 3, 4, and 6 h. Indomethacin concentrations were measured by HPLC method. Pharmacokinetic parameters were calculated by means of the P K Solutions 2.0 program. Results: The pharmacokinetic parameters of indomethacin in 4 patients (group A) who relapsed in IPC overuse were similar to those observed before withdrawal treatment; instead (Table 1) in 5 patients (group B) who steadily discontinued IPC combination, indomethacin disposition was significantly different from that observed before withdrawal treatment. Table 1. Pharmacokinetic parameters of indomethacin in group B. Parameter Before withdrawal After withdrawalHalf life (h) 2.74+0.98 1.45+0.34 *AUC0-t (mg/h/ml) 13.02+6.62 5.36+2.36 *Cl (ml/h/Kg) 64.05+30.16 123.98+39.91 *
*P <0.05 (paired Student’ t-test)Conclusions: In headache patients who discontinued IPC overuse, indomethacin clearance increased and reverted to values previously obtained in occasional IPC users (1).1. Ferrari A., Savino G., Gallesi D., Pinetti D., Bertolini A., Sances G., et al. (2006) Pharmacol Res. 542: 142-149
Serotoninergic system changes during heroin abuse and their reversibility after abuse discontinuation
No full textSubjects affected by heroin dependence have a decreased funcionality of the central serotoninergic system potentially reversible after prolonged drug-abuse discontinuation and treatment with antagonist
Kinetics of indomethacin in headache patients who abitually take an association of indomethacin, caffeine and prochlorperazine
No full textIndomethacin, in combination with prochlorperazine and caffeine (IPC), is often overused by migraine patients who develop medication-overuse headache. Indomethacin clearance is lower in chronic migraine patients overusing IPC combination than in migraine patients only occasionally taking it. Objective: to verify if indomethacin reduced clearance reverts to normal after withdrawal of the overused IPC combination.
Methods: We repeated the study of indomethacin pharmacokinetics in 9 female chronic migraine patients after 3 months from inpatient withdrawal treatment from IPC combination overuse. The IPC combination (indomethacin 50 mg, prochlorperazine 8 mg, caffeine 150 mg) habitually taken was administered by rectal route to each patient. Blood samples were drawn before dosing and at the following post-dose times: 0.5, 1, 2, 3, 4, and 6 h. Indomethacin concentrations were measured by HPLC method.
Results: Pharmacokinetic parameters of indomethacin in 4 patients who relapsed into IPC overuse were similar to those observed before withdrawal treatment; on the other hand, indomethacin clearance reverted to values consistent with published data in 5 patients who discontinued IPC combination overuse.
Conclusions: Indomethacin normal clearance was related to a reduced frequency of migraine; conversely, indomethacin delayed clearance sustained medication-overuse headache
Serum concentrations of vitamin B12 and folate in chronic daily headache.
No full textLower serum vitamin B12 and folate levels were detected in chronic headache patients without anemia. Since these vitamins are important for monoamine metabolsim their deficiency could complicate the headache
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
The role of desferrioxamine chelatable iron in rat liver mitochondrial dysfunction in chronic dietary iron overload
No full textLipid peroxidation and organelle dysfunction are important factors in hepatic iron toxicity. The form of the intracellular iron responsible for these abnormalities is still unknown. In order to investigate the iron species inducing cell injury, the level of chelatable iron in the liver mitochondria isolated from rats fed a 2.5% carbonyl iron diet for 12 weeks was measured by EPR spectroscopy. The presence of lipid peroxidation products and the energy transducing capability of the mitochondrial inner membrane was evaluated in parallel. The total iron concentration in the liver mitochondria from iron fed rats progressively increased up to 6 weeks, almost reaching a steady-state. By contrast the level of chelatable iron in mitochondrial fraction transiently increased at about 3-6 weeks of treatment. The induction of lipid peroxidation and a large decrease of ATP occurred at the same time. The enhancement of the energy dissipating calcium cycling was in parallel revealed by studying the mitochondria membrane potential. These results gave experimental evidence to the proposal that the chelatable iron level plays a critical role in initiating organelle dysfunction, at least in this experimental model
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
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