Improving the analysis of esophageal acid exposure by a new parameter: area under H+

OBJECTIVES: We aimed to compare the data provided by 24-h continuous esophageal pH monitoring in a group of patients with gastroesophageal reflux disease (GERD) to those from a group of healthy volunteers using both conventional parameters and calculated area under the curve of hydrogen ion activity (AUH+), a new value that describes the true acid exposure, through both duration and depth of acidity changes. METHODS: Thirty healthy controls and 60 patients with GERD (30 symptomatic patients without endoscopic esophagitis or nonerosive GERD and 30 symptomatic patients with Savary I-IV endoscopic esophagitis or erosive GERD) were enrolled in a study based on 24-h pH monitoring to compare reference values by means of receiver operating characteristic (ROC) discriminant analysis. RESULTS: The best ROC cutoff value for nonerosive GERD patients was AUH+ = 103.7 (mmol/L) x min with sensitivity of 76.7% and specificity of 93.3%. The best ROC cutoff value for erosive GERD patients was AUH+ = 114.1 (mmol/L) x min with sensitivity of 100% and specificity of 96.7%. These cutoff values increase the sensitivity by 16.7% for nonerosive GERD patients and 10% for erosive GERD patients when compared to a common parameter such as the percentage of total time pH is <4 with a limit of 4.2%. CONCLUSIONS: AUH+ is a valid quantitative parameter to measure 24-h esophageal acid exposure. It may be a reliable and significant clinical aid because it is a more sensitive test in discriminating negative or positive adult patients with or without esophagitis who are submitted to 24-h esophageal pH monitoring.     

Passive avoidance response in mice infected with Schistosoma mansoni

Schistosomiasis is a parasitic disease of humans and rodents affecting more than 200 million people worldwide. Following the onset of infection, the worms induce granulomas around schistosome eggs in the liver, intestine and central nervous system (both brain and spinal cord), which are likely to cause changes in cognitive functions. In the present study, CD-1 female mice were percutaneously infected with 60 cercariae of Schistosoma mansoni and the effect on the mice's cognitive abilities were assessed by using the passive avoidance learning paradigm both in an early and a late phase of infection (independent groups). The results of the study show that infected animals without brain granulomas (early phase) had impairments in their passive avoidance response, whereas mice with brain granulomas (late phase) behaved as uninfected ones. Moreover, a decreased propensity to start exploration was observed in mice with granulomas in the brain. The results suggest that the murine model of infection may be a useful tool for studying human neuroschistosomiasis.     

Interobserver agreement in staging gastric malt lymphoma by EUS

BACKGROUND: EUS is highly accurate for staging gastric lymphoma. Because stage correlates to outcome, interobserver agreement is mandatory. However, previous studies suggest that interobserver agreement might vary according to T-stage. A multicenter evaluation of observer agreement with respect to endosonographic staging of gastric mucosa-associated lymphoid tissue (MALT) lymphoma was therefore conducted. METHODS: Fifty-four patients were studied; 42 were also evaluated after eradication of Helicobacter pylori infection. EUS was performed at different institutions by 10 experienced endosonographers who collected the best photographs for each examination. Interobserver agreement was estimated with kappa statistics. RESULTS: Overall interobserver agreement for T-stage was fair, both before and after treatment (kappa = 0.38 and kappa = 0.37, respectively). Overall interobserver agreement for N-stage was substantial before treatment, but only fair after treatment (kappa = 0.63 and kappa = 0.34, respectively). The lowest values of agreement occurred with T1sm (submucosa) and T2 stage lesions. CONCLUSIONS: Interobserver agreement for staging of gastric MALT lymphoma by EUS is suboptimal before as well as after treatment of H pylori infection. This evidence suggests that gastric EUS may be more difficult technically compared with EUS of other organs. Lack of agreement is crucial because it influences the choice of therapy and assessment of response to treatment. Good interobserver agreement would permit better communication concerning the clinical status of patients, comparison of the results of different studies, and stratification of patients within clinical trials.