Electroesophagogram in gastroesophageal reflux disease with a new theory on the pathogenesis of its electric changes

BACKGROUND: In view of the disturbed esophageal peristaltic activity and abnormal esophageal motility in gastroesophageal reflux disease, (GERD), we investigated the hypothesis that these changes result from a disordered myoelectric activity of the esophagus. METHODS: The electric activity of the esophagus (electroesophagogram, EEG) was studied in 27 patients with GERD (16 men, 11 women, mean age 42.6 ± 5.2 years) and 10 healthy volunteers as controls (6 men, 4 women, mean age 41.4 ± 4.9 years). According to the Feussner scoring system, 7 patients had a mild (score 1), 10 a moderate (score 2) and 10 a severe (score 3) stage of the disease. One electrode was applied to the upper third and a second to the lower third of the esophagus, and the electric activity was recorded. The test was repeated after the upper electrode had been moved to the mid-esophagus. RESULTS: The EEG of the healthy volunteers showed slow waves and exhibited the same frequency, amplitude and conduction velocity from the 2 electrodes of the individual subject, regardless of their location in the upper, middle or lower esophagus. Action potentials occurred randomly. In GERD patients, score 1 exhibited electric waves' variables similar to those of the healthy volunteers. In score 2, the waves recorded irregular rhythm and lower variables than the controls. Score 3 showed a "silent" EEG without waves. CONCLUSION: The electric activity in GERD exhibited 3 different patterns depending on the stages of GERD. Score 1 exhibited a normal EEG which apparently denotes normal esophageal motility. Score 2 recorded irregular electric waves variables which are presumably indicative of decreased esophageal motility and reflux clearance. In score 3, a "silent" EEG was recorded with probably no acid clearance. It is postulated that the interstitial cells of Cajal which are the electric activity generators, are involved in the inflammatory process of GERD. Destruction of these cells appears to occur in grades that are in accordance with GERD scores. The EEG seems to have the potential to act as an investigative tool in the diagnosis of GERD stages

A computational model of ureteral peristalsis and an investigation into ureteral reflux.

The aim of this study is to create a computational model of the human ureteral system that accurately replicates the peristaltic movement of the ureter for a variety of physiological and pathological functions. The objectives of this research are met using our in-house fluid-structural dynamics code (CgLes-Y code). A realistic peristaltic motion of the ureter is modelled using a novel piecewise linear force model. The urodynamic responses are investigated under two conditions of a healthy and a depressed contraction force. A ureteral pressure during the contraction shows a very good agreement with corresponding clinical data. The results also show a dependency of the wall shear stresses on the contraction velocity and it confirms the presence of a high shear stress at the proximal part of the ureter. Additionally, it is shown that an inefficient lumen contraction can increase the possibility of a continuous reflux during the propagation of peristalsis

Export Diversification and CO2 Emissions: An Augmented Environmental Kuznets Curve

International audienc

Can Economic Growth be Sustainable? The Case of EU27

Since the economy is embedded on environment, and since the environment is an important factor of economic growth, the problem of pollutions and resources exhaustion is receiving increasing attention of economists. The question at stake is whether economic growth can be compatible with environmental quality. Testing the possibility of a sustainable economic growth, for an EU27 case study, this paper brings analytical value to this discussion. Considering a double function of natural capital, that is a provider of materials and an absorber of emissions, this paper relates air pollutant emissions and material input data to GDP in order to test the de-pollution and the dematerialization hypothesis. Based on technological progress and income elasticity of environmental quality demand, they depict a positive correlation between income growth and environmental quality. In order to test these hypotheses a quadratic and a cubic version of the Environmental Kuznets curve, that is the theoretical bases for de-pollution and de-materialization hypothesis, have been performed. The EU27 data about pollutant emissions, material consumption and GDP has been provided by EUROSTAT. Results show that, for EU27, economic growth increased the carbon dioxide emissions and the domestic material consumption