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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
How should Helicobacter pylori negative patients be managed?
Full text linkDyspepsia is a digestive syndrome distinct from (although frequently overlapping with) gastroesophageal reflux disease (GORD) and irritable bowel syndrome (IBS), which is characterised by various combinations of painful and non-painful symptoms arising from the epigastrium. Dyspepsia can be secondary to a variety of diseases, but in most instances it is idiopathic. Helicobacter pylori infection is responsible for the majority of peptic ulcers and of other diseases potentially associated with dyspepsia. Nevertheless, a causal role for H pylori infection in symptom occurrence has not been established. Experimental data indicate that H pylori eradication does not improve symptoms in the majority of dyspeptic patients. It has been proposed recently that H pylori negative patients should be managed according to their clinical presentation. Some reports suggest that taking into consideration the most relevant or 'predominant' symptom may help to identify distinct subgroups among dyspeptic patients with different underlying pathophysiological abnormalities and different responses to treatment. Well designed and conducted prospective studies are needed to verify whether treatment of H pylori negative dyspeptic patients based on the predominant symptom actually is a cost effective approach
Management of dyspeptic patients by general practitioners and specialists
Full text linkTherespectiverolesofgeneralpractitioners andspecialistsinthemanagementofmostdiseasesisnotclearlyde®nedanddyspepsiaisno exception.Ideally,thedivisionoftasksshould bebasedonthecharacteristicsofdiVerentdiseasesandonspeci®cobjectives. Theprevalenceofdyspepsiarangesbetween 20and40%inindustrialisedcountriesand roughly25%ofpatientsseekmedicalhelp, whereastheremainderoftenself-medicate.1 Althoughfrequentlyidiopathic(orfunctional), dyspepsiacanbesecondarytoavarietyofserious(andsometimesfatal)organic,systemic andmetabolicdiseasesthatneedtobe identi®ed.Functionaldyspepsiaalsoprecipitatesasubstantialreductioninthequalityof lifeofaVectedpatientswithrelevantcostsfor society.Thecurrenteconomicrestrictionspreventreferralofeverypatientandcorrectmanagementofdyspepsiaisaformidabletask. Prospectivestudieshavebeenundertakento establishtherespectiveeVectivenessofdiVerentdoctorsinthemanagementofsomegastroenterologicaldiseases.Zarlingetalcompared theeYcacyofmanagementofacutediverticulitisprovidedbygeneralpractitioners,internistsandgastroenterologists,andobserved shorterhospitalstayandlowerreadmission ratesinpatientstreatedbygastroenterlogists.2 Unlikeacutediverticulitis,dyspepsiaisavery heterogeneousconditionandnosimilarstudies areavailableasyet.Tacklingthefollowing questionsmayhelptoelucidatetheremitof diVerentdoctors. +Whatdrivesadyspepticindividualto consultaphysician? +DodiVerentdoctorsseediVerenttypesof dyspepticpatients? +Whatisthediagnosticyieldofanextensive work-upbyaspecialist? +ShoulddiVerentdoctorsadoptdiVerent strategiesforthemanagementofdyspepsia? +Whatisthemostcost-eVectivewaytomanagedyspepsia
New developments in the treatment of functional dyspepsia
No full textFunctional dyspepsia is a clinical syndrome defined by chronic or recurrent pain or discomfort in the upper abdomen of unknown origin. Although generally accepted, investigators differently interpret this definition and clinical trials are often biased by inhomogeneous inclusion criteria. The poorly defined multifactorial pathogenesis of dyspeptic symptoms has hampered efforts to develop effective treatments. A general agreement exists on the irrelevant role played by Helicobacter pylori in the pathophysiology of functional dyspepsia. Gastric acid secretion is within normal limits in patients with functional dyspepsia but acid related symptoms may arise in a subgroup of them. Proton pump inhibitors appear to be effective in this subset of patients with dyspepsia. Non-painful dyspeptic symptoms are suggestive of underlying gastrointestinal motor disorders and such abnormalities can be demonstrated in a substantial proportion of patients. Postprandial fullness and vomiting have been associated with delayed gastric emptying of solids, and early satiety and weight loss to postcibal impaired accommodation of the gastric fundus. Prokinetics have been shown to exert beneficial effects, at least in some patients with dyspepsia. In contrast, drugs enhancing gastric fundus relaxation have been reported to improve symptoms, although conflicting results have also been published. An overdistended antrum may also generate symptoms, but its potential pathogenetic role and the effects of drugs on this abnormality have never been investigated formally. Visceral hypersensitivity plays a role in some dyspeptic patients and this abnormality is also a potential target for treatment. Both chemo- and mechanoreceptors can trigger hyperalgesic responses. Psychosocial abnormalities have been consistently found in functional digestive syndromes, including dyspepsia. Although useful in patients with irritable bowel syndromes (IBS), antidepressants have been only marginally explored in functional dyspepsia. Among the new potentially useful agents for the treatment of functional dyspepsia, serotonin 5-HT4 receptor agonists have been shown to exert a prokinetic effect. Unlike motilides, 5-HT4 receptor agonists do not appear to increase the gastric fundus tone and this may contribute to improve symptoms. 5-HT3 receptor antagonists have been investigated mainly in the IBS and the few studies performed in functional dyspepsia have provided conflicting results. Also, κ-opioid receptor agonists might be useful for functional digestive syndromes because of their antinociceptive effects, but available results in functional dyspepsia are scanty and inconclusive. Other receptors that represent potential clinical targets for antagonists include purinoceptors (i. e., P2X2/3 receptors), NMDA receptors (NR2B subtype), protease-activated receptor-2, the vanilloid receptor-1, tachykinin receptors (NK1/NK2) and cholecystokinin (CCK)1 receptors
Review article: The continuing dilemma of dyspepsia
No full textDyspepsia drains a substantial proportion of healthcare resources in industrialized countries and an appropriate management strategy is needed. An aetiological role for Helicobacter pylori infection has been demonstrated in a number of pathological conditions associated with dyspepsia, such as peptic ulcer and gastric malignancies, but not in functional dyspepsia. Endoscopy and diagnosis-based treatment, H. pylori testing and eradication therapy, history taking and empirical therapy, are the main tools that are currently available for managing patients with upper gastrointestinal symptoms. Endoscopy identifies malignancies and organic diseases of the proximal gut and therefore provides reassurance to both doctors and patients. It should be recommended in older patients with suspicious symptoms and it has proven to be more cost-effective than empirical H2-receptor antagonists in patients with ulcer-like symptoms. Empirical eradication in all dyspeptics without suspicious symptoms is a cost-effective approach that cures the majority of peptic ulcers. Nevertheless, it does not control symptoms in the majority of patients, it may exacerbate gastro-oesophageal reflux disease, and it encourages antibiotic resistance. The realities of current clinical practice require empirical therapy in most, if not all, the dyspeptics seen by general practitioners. A detailed history taking can help to diagnose gastro-oesophageal reflux disease and to identify suspicious symptoms. Furthermore, identification of dyspepsia subgroups may provide guidance for empirical therapy. Nevertheless, even analysis of individual symptoms does not provide a sufficient diagnostic yield to differentiate functional from organic dyspepsia and appropriate investigations are needed in patients with poor response to short-term therapy or frequent relapses
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
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