1,720,990 research outputs found
A) Meta-analysis: the relationship between Helicobacter pylori infection and gastro-oesophageal reflux disease.
No full textBACKGROUND: The relationship between Helicobacter pylori infection and its treatment and gastro-oesophageal reflux disease (GERD) is controversial.
AIMS: To establish if H. pylori infection is associated with the presence of GERD and if anti-H. pylori treatment leads to de novo GERD or rebound/exacerbation of GERD.
METHODS: A search of MEDLINE and EMBASE databases was made. Pooled odds ratios (OR) were calculated for de novo GERD and rebound/exacerbated GERD after anti-H. pylori therapy in case-control studies and in therapeutic trials.
RESULTS: Fourteen case-control studies and 10 clinical trials were included. Among case-control studies, pooled OR for the association between H. pylori negative status and GERD was 1.34 [95% confidence interval (CI) 1.15-1.55]. Among therapeutic trials, pooled OR for the association anti-H. pylori therapy - GERD was 2.54 (95% CI 1.92-3.37). The OR for de novo GERD was 3.25 (95% CI 2.09-5.33), and for rebound/exacerbated GERD was 2.39 (95% CI 1.75-3.34). Associations were higher among Asian studies than among North American and European studies.
CONCLUSIONS: This meta-analysis shows significant association between absence of H. pylori infection and GERD symptoms, and a positive association between anti-H. pylori therapy and occurrence of both de novo and rebound/exacerbated GERD. The significance of these associations appears to have been inflated by the effect of single trials and by geographical variations
The relationship between chronic H. pylori infection, CagA seropositivity and stroke: meta-analysis
No full textAIMS: There is contrasting evidence on the relevance of chronic infection by Helicobacter pylori (H. pylori) as a risk factor for stroke. We performed a meta-analysis of case-control studies to assess association of H. pylori infection and more virulent H. pylori strains, bearing the cytotoxin-associated gene-A (CagA) antigen, with different types of stroke.
METHODS: Outcome measures were: H. pylori and CagA seroprevalence in (1) patients with stroke versus controls, and (2) patients with stroke due to large vessel stroke versus patients with other types of stroke and controls.
RESULTS: Seven cross-sectional, case-control studies were included. Odds ratio for individual case-control studies and pooled OR for the association between H. pylori seropositivity and stroke was 1.49 (95% CI 1.24-1.81), for the association between stroke and anti-CagA positivity was 2.23 (95% CI 1.49-3.36). Patients with large vessel stroke had higher odds for H. pylori infection than patients with other types of stroke (odds ratio 1.65; 95% CI 1.12-2.45), and than controls (odds ratio 1.61; 95% CI 1.13-2.32).
CONCLUSIONS: Association between H. pylori positivity, anti-CagA positivity and stroke is modest and seems higher with stroke due to large vessel disease. This meta-analysis suggests that the role of CagA positive H. pylori strains in different stroke etiologic subclasses should be the target of future prospective investigation
Helicobacter pylori treatment: a role for probiotics?
No full textMany new therapeutic strategies are studied to improve Helicobacter pylori eradication rate. Probiotics are live microorganisms which, upon administration, may interact with the human microflora and positively affect the health status. The use of probiotics in the field of H. pylori infection has been proposed for improving eradication rate and tolerability and for compliance of multiple antibiotic regimens used for the infection. Results from laboratory studies and from clinical trials seem to confirm the expectancies, but there is lack of standardization in terms of type of probiotic strain used, dosage and timing of supplementation. Before further ongoing trials and future studies will clarify these points, probiotics could remain a useful adjunct to standard anti-H. pylori therapies, but cannot take the place of other validated options
[Helicobacter pylori and gastric carcinoma]
No full textAmong the suspected bacterial causes of cancer, H. pylori is the agent more consistently linked to malignancy. After its discovery in 1983 and the later confirmation as the leading cause of chronic gastritis, several studies were performed to prove an association between H. pylori infection and gastric carcinoma. The epidemiological data have been so strong that in 1994 the International Association for Research on Cancer stated that "there was sufficient evidence" to classify H. pylori as a group I carcinogen in humans. However, the exact mechanisms underlying the link between H. pylori infection and gastric carcinoma remain still to be elucidated. The natural history of H. pylori infection shows that, although roughly half of the world's human population bears the organism, only a minority of individuals develop clinically important outcomes (e.g. peptic ulcer, lymphoproliferative diseases, atrophic gastritis and gastric carcinoma): host's genetic make-up, duration of infection, diet and differences between H. pylori strains have been proposed as factors potentially able to influence the outcomes in different individuals. The damaging agents by which H. pylori could promote gastric carcinogenesis are produced either by the organism or as a consequence of the host inflammatory response to the infection. Gastric mucosal chronic damage may, therefore, lead to changes in the pattern of epithelial cell kinetic (increase in cell proliferation and induction of apoptosis) in gastric glands which may induce DNA injury with irreversible genetic lesions. Finally, a direct association between H. pylori infection and the induction of gastric carcinoma has been recently demonstrated in an animal model, giving further credence to the role of this organism in gastric carcinogenesis
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
Helicobacter pylori: a culprit in extraintestinal diseases?
No full textHelicobacter pylori: a culprit in extraintestinal diseases
Meta-analysis: the effect of probiotic administration on antibiotic-associated diarrhoea
No full textBACKGROUND: Antibiotic-associated diarrhoea can be attributed in part to imbalances in intestinal microflora. Therefore, probiotic preparations are used to prevent this diarrhoea. However, although several trials have been conducted, no conclusive evidence has been found of the efficacy of different preparations, e.g. Lactobacillus spp. and Saccharomyces spp.
AIM: To conduct a meta-analysis of the data in the literature on the efficacy of probiotics in the prevention of antibiotic-associated diarrhoea.
METHODS: A literature search was performed of electronic databases, Abstract Books and single paper references. Data were also obtained from the authors. Only placebo-controlled studies were included in the search. The Mantel-Haenszel test was used to estimate the relative risk for single studies and an overall combined relative risk, each study being submitted to the Mantel-Haenszel test for homogeneity.
RESULTS: Twenty-two studies matched the inclusion criteria. Only seven studies (881 patients) were homogeneous. The combined relative risk was 0.3966 (95% confidence interval, 0.27-0.57).
CONCLUSIONS: The results suggest a strong benefit of probiotic administration on antibiotic-associated diarrhoea, but further data are needed. The evidence for beneficial effects is still not definitive. Published studies are flawed by the lack of a placebo design and by peculiar population features
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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