Gastric myoelectric and motor activity in dogs with gastric dilatation-volvulus

1993 ◽  
Vol 265 (4) ◽  
pp. G646-G653
Author(s):  
J. A. Hall ◽  
T. N. Solie ◽  
H. B. Seim ◽  
D. C. Twedt
Keyword(s):  
Wave Propagation ◽  
Gastric Emptying ◽  
Slow Wave ◽  
Propagation Velocity ◽  
Delayed Gastric Emptying ◽  
Solid Phase ◽  
Phase Iii ◽  
Gastric Dilatation ◽  
Wave Propagation Velocity ◽  
Gastric Slow Wave

Electrical and contractile properties of the stomach were assessed in six adult dogs after recovery from surgical treatment for gastric dilatation-volvulus (GDV), a disorder characterized by delayed gastric emptying of the solid phase. Electrodes and strain-gauge force transducers were sutured to the serosa of the antrum and pylorus at the time of surgical intervention for GDV. Ten days after implantation, electrical and mechanical activities were recorded before and after a standardized meal. The analog FM tape recordings of the electrical and mechanical signals were converted to digital time series for analysis by computer. Recordings from dogs after GDV showed increased slow wave propagation velocity in both the fasting and the fed states compared with controls. In addition, the GDV dogs had atypical fasting state phase III activity fronts. We found no difference in gastric slow wave frequency, dysrhythmia, or electromechanical coupling between the two groups. These results indicate that delayed gastric emptying in this syndrome is associated with increased gastric slow wave propagation velocity.

Postprandial changes in intestinal slow-wave propagation reflect a decrease in cell coupling

1989 ◽  
Vol 257 (3) ◽  
pp. G463-G469
Author(s):  
D. Terasaka ◽  
A. Bortoff ◽  
L. F. Sillin
Keyword(s):  
Wave Propagation ◽  
Electrical Activity ◽  
Slow Wave ◽  
Propagation Velocity ◽  
Maximum Rate ◽  
Internal Resistance ◽  
Cell Coupling ◽  
Wave Propagation Velocity ◽  
Fasting Level ◽  
Amplitude Maximum

The purpose of these studies was to determine the effects of feeding on jejunal slow-wave propagation velocity (SWPV). Nine cats were instrumented with six pairs of electrodes implanted 4 cm apart on the jejunum. Electrical activity was recorded at the end of an 18-h fast after which each animal was fed 60 g of canned cat food. Recordings were continued during feeding and for several hours thereafter. This procedure was repeated at least twice for each cat. Average SWPV (cm/s) decreased from a fasting level of 2.28 +/- 0.20 (mean of means +/- SE) to 1.93 +/- 0.16 at 10-20 min, 1.51 +/- 0.11 at 1 h, and 1.37 +/- 0.10 at 3 h postprandially. Corresponding SW frequencies (SWFs) were 19.6 +/- 0.3, 18.7 +/- 0.2, 19.2 +/- 0.2, and 19.0 +/- 0.2 cycles/min, respectively. The differences between the fasting SWPV and that at 1 and 3 h were significant (P less than 0.05). When SWPV was plotted as a function of SWF, the slopes of the corresponding curves were also found to decrease postprandially (P less than 0.05, fasting vs. 1 and 3 h). There was no apparent change in SW amplitude, maximum rate of SW depolarization, or threshold. In the absence of changes in these parameters, the divergence of the slopes at lower SWFs indicates that the decrease in SWPV is because of increased internal resistance, probably the result of uncoupling of intestinal muscle cells. The change is rapid in onset and long in duration, suggesting that an uncoupling factor is released during ingestion of a meal, and that its effect persists for several hours.

Mechanisms of burn-induced impairment in gastric slow waves and emptying in rats

2010 ◽  
Vol 299 (1) ◽  
pp. R298-R305 ◽  
Author(s):  
Hanaa S. Sallam ◽  
Hermes M. Oliveira ◽  
Suhuan Liu ◽  
Jiande D. Z. Chen
Keyword(s):  
Gastric Emptying ◽  
Slow Wave ◽  
Delayed Gastric Emptying ◽  
Burn Injury ◽  
Wave Activity ◽  
Cyclooxygenase 2 ◽  
Slow Waves ◽  
Gastric Slow Wave ◽  
Gastric Slow Waves ◽  
Gastric Dysrhythmias

Delayed gastric emptying is common following severe large cutaneous burns; however, the mechanisms of burn-induced delayed gastric emptying remain unknown. The aim of this study was to explore the possible involvement of hyperglycemia and cyclooxygenase-2 receptors in the burn-induced gastric dysrhythmias. Gastric slow waves and gastric emptying were assessed in rats 6 h following sham or burn injury. Animals were randomized to one sham-burn and seven burn groups: untreated; two groups of saline treated (control); insulin treated (5 IU/kg); cyclooxygenase-2 inhibitor treated (10 mg/kg); ghrelin treated (2 nmol/rat); and gastric electrical stimulation treated. It was found that 1) severe burn injury impaired gastric slow waves postprandially and delayed gastric emptying; 2) the impairment in gastric slow waves included a decrease in the slow-wave frequency and in the percentage of normal slow waves, and an increase in the percentage of bradygastria ( P = 0.001, 0.01, and 0.01, respectively vs. preburn values). None of the gastric slow-wave parameters was significantly correlated with gastric emptying; 3) cyclooxygenase-2 inhibitor normalized burn-induced delayed gastric emptying ( P = 0.3 vs. sham-burn), but not gastric dysrhythmias ( P < 0.002 vs. sham), whereas insulin normalized both gastric emptying ( P = 0.4 vs. sham-burn) and gastric dysrhythmias ( P = 0.3 vs. sham-burn); 4) both gastric electrical stimulation and ghrelin accelerated burn-induced delayed gastric emptying ( P = 0.002 and 0.04, respectively, vs. untreated burn). In conclusion, hyperglycemia alters gastric slow-wave activity and delayed gastric emptying, while cyclooxygenase-2 inhibition delays gastric emptying without altering gastric slow-wave activity.

scholarly journals Abnormal gastric slow waves in patients with functional dyspepsia assessed by multichannel electrogastrography

2001 ◽  
Vol 280 (6) ◽  
pp. G1370-G1375 ◽  
Author(s):  
Xuemei Lin ◽  
Jiande Z. Chen
Keyword(s):  
Wave Propagation ◽  
Functional Dyspepsia ◽  
Slow Wave ◽  
Single Channel ◽  
Slow Waves ◽  
Lower Percentage ◽  
Healthy Controls ◽  
Fasting State ◽  
Gastric Slow Wave ◽  
Gastric Slow Waves

The aim of this study was to utilize multichannel electrogastrography to investigate whether patients with functional dyspepsia had impaired propagation or coordination of gastric slow waves in the fasting state compared with healthy controls. The study was performed in 10 patients with functional dyspepsia and 11 healthy subjects. Gastric myoelectrical activity was measured by using surface electrogastrography with a specially designed four-channel device. The study was performed for 30 min or more in the fasting state. Special computer programs were developed for the computation of the propagation and coupling of the gastric slow wave. It was found that, compared with the healthy controls, the patients showed a significantly lower percentage of slow wave propagation (58.0 ± 8.9 vs. 89.9 ± 2.6%, P < 0.002) and a significantly lower percentage of slow wave coupling (46.9 ± 4.4 vs. 61.5 ± 6.9%, P < 0.04). In addition, the patients showed inconsistencies in the frequency and regularity of the gastric slow wave among the four-channel electrogastrograms (EGGs). It was concluded that patients with functional dyspepsia have impaired slow wave propagation and coupling. Multichannel EGG has more information than single-channel EGG for the detection of gastric myoelectrical abnormalities.

scholarly journals A coupling model based on grey relational analysis and stepwise discriminant analysis for wood defect area identification by stress wave

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1171-1186
Author(s):  
Xin Li ◽  
Wei Qian ◽  
Liting Cheng ◽  
Lihong Chang
Keyword(s):  
Wave Propagation ◽  
Stress Wave ◽  
Propagation Velocity ◽  
Wood Specimen ◽  
Coupling Model ◽  
Stress Wave Propagation ◽  
Sectional Area ◽  
Wave Propagation Velocity ◽  
Cross Sectional ◽  
Stress Wave Propagation Velocity

Based on the experimental idea of reverse simulation, a quantitative area of hole was excavated at the sectional center of a wood specimen. The excavation area was 1/32S, 1/16S, 1/8S, 1/4S, and 1/2S (where S represents cross-sectional area of the complete specimen) and stress wave nondestructive testing of six sensors was performed. The stress wave propagation paths were statistically summarized to obtain the stress wave propagation velocity (Va) for two adjacent sensors, the stress wave propagation velocity (Vb) for two separated sensors, and the stress wave propagation velocity (Vc) for two opposite sensors. Furthermore, by analyzing the advantages and disadvantages of grey relation and stepwise discriminant model when both of them were used alone, a coupling model generated from them was established to dispose the test data. The attenuation ratios Ψa, Ψb, and Ψc of stress wave under three propagation paths and their relation ratios Va/Vb, Vb/Vc, and Va/Vc, a total of six groups of measured data, were selected as discriminant factors for the hole area grade of the wood specimen. The verification results showed that the discriminant accuracy of the coupling model was 100%, and it was concluded that the attenuation ratio (Ψb) of the stress wave propagation velocity for two separated sensors had the strongest discriminant ability against cross-sectional area of the specimen.

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