1,721,041 research outputs found
Impedance-pH reflux patterns can differentiate non-erosive reflux disease from functional heartburn patients.
No full textINTRODUCTION: Symptom association is important to distinguish non-erosive reflux disease [NERD; abnormal oesophageal acid exposure time (AET) and/or positive symptom association] from functional heartburn (FH; normal AET and negative symptom association). Asymptomatic patients during reflux monitoring are challenging as symptom association cannot be assessed.
AIM: To evaluate whether impedance-pH reflux patterns are useful to differentiate NERD from FH.
METHODS: Endoscopy-negative reflux patients underwent impedance-pH off-therapy. Oesophageal AET, characteristics of reflux episodes and symptom association probability (SAP) were measured. Twenty patients asymptomatic during the first test repeated a second examination.
RESULTS: Of 329 patients, 130 (40%) were pH-POS, 120 (36%) pH-NEG/SAP+ (hypersensitive oesophagus = HO) and 79 (24%) pH-NEG/SAP- (FH). Total and acid reflux episodes were significantly higher (p < 0.01) in pH-POS compared to pH-NEG/SAP+, pH-NEG/SAP- and healthy volunteers (HVs). Patients pH-NEG/SAP+ had a significantly increased number of weakly acidic reflux episodes compared to pH-POS, pH-NEG/SAP- and HVs (p < 0.01). The rate of proximal reflux episodes in pH-POS (50%) and pH-NEG/SAP+ (47%) was higher (p < 0.01) than in pH-NEG/SAP- (33%) and HVs (33%). Measuring AET, number of reflux episodes and percentage of proximal reflux events permits to identify FH in 70% of cases and HO in 80% of cases who repeated the examination.
CONCLUSION: In patients with normal AET and SAP+, increased number of weakly acidic reflux and higher rate of proximal reflux are the main discriminant features. There is large overlap between FH and HVs. These differences can be of help in diagnosing patients with normal oesophageal acid exposure who fail to have symptoms during MII-pH testing
The role of nonacid reflux in NERD: lessons learned from impedance-pH monitoring in 150 patients off therapy.
No full textINTRODUCTION: Nonerosive reflux disease (NERD) is the most common form of gastroesophageal reflux disease. While the role of acid reflux has been established, the relevance of nonacid reflux in generating symptoms in NERD is unknown.
AIM: To evaluate the diagnostic utility of impedance-pH monitoring in NERD patients.
METHODS: Patients with typical reflux symptoms (heartburn and/or regurgitation) and normal endoscopy (NERD) underwent a combined impedance-pH monitoring off proton pump inhibitor (PPI) therapy. Previously investigated 48 healthy volunteers served as controls. Distal esophageal acid exposure (% time pH = 50%), and symptom association probability (SAP; positive if >= 95%) were calculated.
RESULTS: Between June 2004 and June 2007, 150 NERD patients (82 women, mean age 48 yr, range 18 78 yr) reported symptoms during the impedance-pH monitoring. NERD patients had more reflux episodes (median [25th-75th percentile]) compared with healthy volunteers (total: 46 [26-65] vs 32 [18-43], P< 0.05; acid: 29 [14-43] vs 17 [8.5-31.0], P< 0.05; and nonacid: 20 [15-27] vs 18 [13.5-26.0], P = NS). Sixty-three (42%) patients had abnormal % time pH < 4. Among 87 patients with normal % time pH< 4., 22 (15%) had a positive SAP for acid, 19 (12%) for nonacid reflux, and 7 (5%) for both. Classifying patients with symptomatic nonacid reflux as having a hypersensitive esophagus reduced the number of patients with functional heartburn from 65 (43%) to 39 (26%).
CONCLUSION: Monitoring for nonacid reflux in NERD patients reduces the proportion of patients classified as having "functional heartburn." Studies assessing the clinical implications of these findings are warranted
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Esophageal hypertensive peristaltic disorders
No full textEsophageal motility abnormalities include a series of manometric findings that differ to a significant degree from findings in normal, asymptomatic volunteers
Symptom association probability for acid and non-Acid reflux in patients with erosive esophagitis (EE) and non-Erosive reflux disease (NERD).
Get PDFVariations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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