1,720,988 research outputs found
Placebo and placebo effect: their impact on the evaluation of drug response in patients.
No full textPlacebo, defined as any therapeutic procedure, without any specific activity, given deliberately to have an effect on a patient, symptom, syndrome or disease, has a great impact in the evaluation of drug response. The possible pathways via which the possible effect brings about clinical and physiological changes remain unknown, but a humoral mechanism seems to be implicated in some placebo effects (e.g. placebo-induced analgesia). The placebo effect depends on many factors, including the type of patient, the personality of the physician, the doctor-patient relationship and the type and even the colour of the drug preparation. Placebo control is important particularly when the disease is characterized by frequent spontaneous periods of acute exacerbation and remission. Functional (such as dyspepsia and irritable bowel syndrome) and organic (such as peptic ulcer and inflammatory bowel disease) gastrointestinal diseases have got great benefit from placebo-controlled clinical trials. In such trials the more effective the placebo is, the more difficult it will be to demonstrate the efficacy of active drug in statistical terms. Nevertheless, provided the use of placebo be ethical for a given condition, placebo-controlled trials are the only objective way of assessing correctly drug response in patients
Novel non-steroidal anti-inflammatory drugs: what we have learned from animal studies
No full textThe use of non-steroidal anti-inflammatory drugs (NSAIDs) is frequently associated with serious adverse effects related to the inhibition of cyclooxygenase (COX) in tissues where prostanoids exert physiological effects, such as gastric mucosal defence, renal homeostasis and platelet aggregation. The discovery of a second COX isoform (COX-2) specifically induced in pathological tissues led to the development of selective COX-2 inhibitors, believed to have an improved safety profile compared to traditional NSAIDs. Animal studies, however, have revealed a protective role for the COX-2 enzyme in the stomach, kidney, heart, vasculature and reproductive system, and therefore, the safety of COX-2 selective inhibitors needs to be reassessed. On the other hand, new therapeutic indications have emerged as a result of the role played by COX-2 overexpression in cancer or Alzheimer's disease. A second approach aimed at obtaining safer NSAIDs is based on the gastroprotective effects of nitric oxide (NO). Traditional NSAIDs chemically linked to NO-releasing moieties retain the therapeutic efficacy, but not the adverse effects, of the parent NSAIDs. Moreover, additional therapeutic applications in cardiovascular diseases, Alzheimer's disease and cancer have been suggested. Animal data, however, need to be confirmed in large clinical trials. Finally, the increase in endogenous NO via a selective increase in inducible NO synthase in the gastric mucosa is the mechanism underlying the good gastric tolerability and the gastroprotective effects of the non-selective NSAID amtolmetin guacyl, documented to date in the ra
Receptor Antagonists: Is There a Place in the Treatment of Helicobacter pylori Infection?
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L'attività xantino-ossidasica epatocitaria nelle siderocromatosi primitive e secondarie
No full textLa ricerca porta in luce i risultati sull''attività xantino-ossidasica epatocitaria nelle siderocromatosi primitive e secondari
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
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