Gastric Electrical Activity
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. AproximaÃÃo espectral e construÃÃo de wavelets com aplicaÃÃes em eletrogastrografia / Spectrum approximation and wavelet design with applications in electrogastrography
Signal analysis is one of the most important areas of Signal Processing. This thesis is divided in three parts, each one addressing a specific topic of signal analysis. The sub-areas were: (i) approximate methods for spectrum evaluation; (ii) wavelet design; and (iii) biomedical signal analysis. The problem of spectrum estimation under constraints of minimal
Publicado em: 2005
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2. Normal gastric antral myoelectrical activity in early onset anorexia nervosa.
Anorexia, epigastric discomfort, nausea, and vomiting may result from disordered gastric motility and emptying. These features have been found in many adults with anorexia nervosa, but have never been investigated in early onset anorexia nervosa. In 14 patients with early onset anorexia nervosa (eight of whom had upper gastrointestinal tract symptoms), six c
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3. Comparison of membrane electrical activity of cat gastric submucosal arterioles and venules.
Intracellular electrical recordings were made from arterioles and venules of the cat gastric submucosa. Spontaneous rhythmic fluctuations of the membrane potential were recorded in 54% of the venular preparations. Arteriolar cells showed no spontaneous activity. Excitatory junction potentials were recorded in arterioles but not venules after single shocks to
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4. Effects of phosphodiesterase inhibitors on spontaneous electrical activity (slow waves) in the guinea-pig gastric muscle.
1. The effects of the phosphodiesterase inhibitors caffeine, theophylline, isobutylmethylxanthine (IBMX) and rolipram on spontaneous electrical activity (slow waves) were studied in the circular muscle of the guinea-pig gastric antrum. 2. All the inhibitors reduced slow wave frequency without changing the membrane potential and the slow wave configuration, b
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5. Interstitial cells of Cajal generate spontaneous transient depolarizations in the rat gastric fundus
Intracellular recordings were made from isolated circular muscle bundles of rat gastric fundus. The majority of cells generated an ongoing discharge of electrical activity that were ≤10 mV in amplitude (unitary potentials). A second pattern of electrical activity was recorded in less than 1% of all impalements. This electrical activity was characterized by
American Physiological Society.
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6. Organization of electrical activity in the canine pyloric canal.
1. The electrical activity of the canine gastroduodenal junction was investigated using cross-sectional muscle preparations and intracellular recording techniques. 2. Spontaneous electrical slow waves were recorded from antral and pyloric cells but not from duodenal cells adjacent to the pyloric region. Slow waves were generated in the antrum and propagated
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7. Electrical behaviour of myenteric neurones in the gastric corpus of the guinea-pig.
1. Electrical behaviour of ganglion cells in the myenteric plexus of the guinea-pig stomach was investigated using intracellular recording methods. 2. Three subpopulations were identified and classified for convenience of discussion as gastric I, II and III neurones. Gastric I neurones were characterized by repetitive spike discharge during depolarizing curr
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8. Participation of Ca2(+)-activated K+ channels in electrical activity of canine gastric smooth muscle.
1. The hypothesis that Ca2(+)-activated K+ channels participate in the repolarization of electrical slow waves was tested in isolated cells and intact muscles of the canine gastric antrum. 2. Freshly dispersed cells from the gastric antrum liberally express large conductance channels that were characterized as Ca2(+)-activated K+ channels by several criteria
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9. Gastric pH changes associated with duodenal motility in fasted dogs.
1. The electrical activity of the antrum and duodenum was recorded from chronically implanted electrodes in six conscious dogs fitted with gastric and/or duodenal cannulae. Antral and duodenal pH were concomitantly registered using glass electrodes inserted through the respective cannula. 2. In dogs fasted for 18-24 h an alkalinization of the antrum of about
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10. Slow wave heterogeneity within the circular muscle of the canine gastric antrum.
A cross-sectional preparation was designed in which multiple micro-electrodes can be precisely positioned to impale smooth muscle cells anywhere from the serosa to the submucosa. Intracellular electrical recordings were obtained from gastric antral circular muscle cells from the myenteric plexus to the submucosa. The resting membrane potential changed linear
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11. Interstitial cells of Cajal mediate mechanosensitive responses in the stomach
Changes in motor activity are a basic response to filling of smooth muscle organs. Responses to gastric filling, for example, are thought to be regulated by neural reflexes. Here, we demonstrate a previously uncharacterized aspect of stretch-dependent responses in visceral smooth muscles that is mediated by mechanosensitive interstitial cells of Cajal. Lengt
National Academy of Sciences.
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12. Prostaglandin regulation of gastric slow waves and peristalsis
Gastric emptying depends on functional coupling of slow waves between the corpus and antrum, to allow slow waves initiated in the gastric corpus to propagate to the pyloric sphincter and generate gastric peristalsis. Functional coupling depends on a frequency gradient where slow waves are generated at higher frequency in the corpus and drive the activity of
American Physiological Society.