1,721,347 research outputs found
Gastroparesis: separate entity or just a part of dyspepsia?
Gastroparesis is defined by the presence of delayed gastric emptying (GE) in the absence of mechanical obstruction. Symptoms that have been attributed to gastroparesis include postprandial fullness, early satiation nausea and vomiting. Gastroprokinetic drugs are the preferred treatment option. A number of problems with the concept of gastroparesis have been identified recently. Major overlap exists with the symptom complex of the functional dyspepsia subtype of postprandial distress syndrome. The distinguishing feature of gastroparesis is delayed GE, but the correlation between delayed emptying and symptom pattern or severity in gastroparesis is modest and the stability of delayed emptying over time is poor. Other pathophysiological mechanisms such as hypersensitivity or impaired accommodation may also underlie symptoms in patients with gastroparesis. Moreover, symptomatic response to prokinetic therapy is variable and cannot be predicted based on the degree of enhancing GE. A number of approaches have been proposed to increase clinical usefulness of a diagnosis of gastroparesis, including a higher threshold of abnormal emptying and selection of patients with a specific symptom pattern more likely to be associated with delayed emptying
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Reproducibility of gastric barostat studies in healthy controls and in dyspeptic patients.
OBJECTIVES:
Gastric barostat studies are increasingly being performed, but their reproducibility and the most suitable study protocol have not been determined. The aim of this study was to verify the reproducibility of gastric sensitivity and accommodation testing in healthy and in dyspeptic subjects, and to compare stepwise and double random staircase distensions.
METHODS:
A total of 13 dyspeptic patients and 25 healthy control subjects underwent two successive studies. Sensory thresholds were assessed on a same-day/different-days protocol, using a stepwise (11/14 healthy subjects and 11/13 patients) or a double random staircase inflation (11/21 healthy subjects). In 10 healthy subjects, both methods were compared. Gastric accommodation was measured on different days in 13 patients and nine healthy subjects. Data (mean +/- SEM) were compared using the paired t test, and individual variability was expressed as the percent coefficient of variation.
RESULTS:
In healthy subjects, the thresholds for first perception and for discomfort were highly reproducible (p > 0.05) and the pressure thresholds showed a lower degree of variability than the volumes. Pressure thresholds quantified by stepwise showed lower variability than double random staircase inflation. In the patients, the sensory thresholds were unchanged between the sessions on the same and on different days (p > 0.05). Gastric accommodation also showed excellent reproducibility for both dyspeptic patients and healthy control subjects (p > 0.05).
CONCLUSIONS:
Both in dyspeptic patients and in healthy control subjects, gastric sensitivity and accommodation quantified by isobaric distensions show excellent reproducibility. Pressure and volume thresholds both are well reproducible, but the former shows less variability. Finally, the simplest stepwise protocol is better than the double random staircase to assess the gastric sensitivity to distensio
Is the irritable bowel really irritable?
We studied 5 healthy volunteers and 9 patients with irritable bowel syndrome (IBS) during infusion of the colon with saline solution, bile acids, fatty acids and balloon distension. Our results show that the pain threshold was significantly (p < 0.001) higher in controls than in IBS patients. Bile acids and fatty acids brought on the habitual pain in 5/7 and 7/8 patients respectively, while they did not have any effect in the control group. On the basis of our data we can conclude that the IBS patients are more sensitive to colonic distension and perfusions, thus suggesting a non-specific irritability of the colon which could be a characteristic of these patients
Microbiota in health and irritable bowel syndrome: current knowledge, perspectives and therapeutic options.
The gastrointestinal tract is a natural reservoir of microbiota. The gut is germ-free at birth, but rapidly becomes host to various bacteria establishing a progressively mutual relationship. The composition of gut microbiota is individual-specific and depends on the genotype of the host and environmental factors. Novel techniques have been used to characterize gastrointestinal microbiota, including genomic approaches. The bacterial profile shows that dominant and minor phyla are present in the gastrointestinal tract. From the proximal to the distal segments of the gut the bacterial density gradually increases, reaching an estimated 10(11) to 10(12) bacteria per gram of colonic content. Dynamic interactions between gut and microbiota play a physiological role in metabolic, protective and structural functions, while dysbiosis contributes to several diseases. Microbiota appear to play a role in IBS, where qualitative and quantitative changes of bacteriaoccur in IBS subtypes. Initial therapeutic approaches in IBS have focused on microbiota. The relationship between perturbations of the microbiota, mucosal inflammation and IBS remains to be further investigated
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