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Myoelectric Activity (myoelectric + activity)
Selected AbstractsThe Characterization of Contractile and Myoelectric Activities in Paralyzed Tibialis Anterior Post Electrically Elicited Muscle FatigueARTIFICIAL ORGANS, Issue 4 2010Nan-Ying Yu Abstract This study aimed to understand the myoelectric and mechanical characteristics of muscle recovering from electrically elicited fatigue. A modified Burke fatigue protocol was delivered to activate the tibialis anterior of 13 spinal cord injured subjects for 4 min. Before and after the fatigue protocol, a series of pulse trains was delivered to induce three twitches and a fused contraction at 0, 1, 3, and 5 min and then followed every 5 min for 60 min. The recovery processes of the ankle dorsiflexion torque and the evoked electromyography (EMG) parameters were analyzed and characterized by a first-order exponential equation. The recovery process was found to be faster in regard to tetanic muscle contraction. Factors relating to low-frequency fatigue, postfatigue potentiation, and the quickly normalized relaxation rate were taken into account for the discussion of this result. During the recovery process, the disassociation was found not only between twitch and tetanic contractions but also between mechanical and myoelectric activities. After the complete normalization of EMG parameters from about 15 min post fatigue, the tetanic force recovered incompletely to an asymptotic level. [source] The feasibility and reliability of using circular electrode for sphincter of Oddi electromyography in anaesthetised rabbitsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2009F. Chen Abstract, Sphincter of Oddi manometry (SOM) is the gold standard for assessing sphincter of Oddi dysfunction (SOD), but is considered a diagnostic sensitivity of 30,80% and associated with significant complications of pancreatitis. Electromyography (EMG) of sphincter of Oddi (SO) using a circular electrode (CE) may be useful in improving diagnostic accuracy and reducing complications. To evaluate the feasibility and reliability of the CE, we record myoelectric activity of SO in rabbits using the CE to compare with the traditional needle electrode (NE). The CE was prepared using a double-channel biogel catheter with two silver rings at the head of the catheter. The CE was then inserted into the lumen of the SO through the duodenal papilla, and myoelectric activity was recorded in the SO in 30 rabbits. An EMG recorded using an NE was performed at the same time, when the SO was in basal state, after injection of cholecystokinin and N-butylscopolamine bromide. Electromyographs recorded by the two methods were then evaluated. Satisfactory SO EMGs were acquired using the CE without any injury. Simultaneous recording revealed a very similar traces and one-to-one correspondence of SO spike bursts (SOSB). Linear regression analysis showed a significant direct correlation between the two methods for SOSB duration and amplitude. The results suggested that CE was comparable with NE in terms of recording efficacy. The CE also has advantages of easy fixation, accurate localisation, broad applicability and ease of achieving satisfactory outcomes without trauma, compared with the NE. [source] The incretin hormones GIP and GLP-1 in diabetic rats: effects on insulin secretion and small bowel motilityNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2009T. Edholm Abstract, Incretin hormones often display inhibitory actions on gut motility. The aim of this study was to investigate if altered responsiveness to glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) as regards insulin release and small bowel motility could bring further clarity to the pathophysiology of diabetes in the Goto-Kakizaki (GK) rat. The isolated perfused pancreas was studied in male GK and Wistar rats (controls) under euglycemic and hyperglycemic conditions. Glucose-dependent insulinotropic peptide (10 nmol L,1) or GLP-1 (10 nmol L,1) were added to the medium and perfusate was collected and analysed for insulin. Moreover, GK and Wistar rats were supplied with bipolar electrodes in the small bowel and myoelectric activity was recorded during intravenous administration of GIP (1,400 pmol kg,1 min,1) or GLP-1 (0.1,20 pmol kg,1 min,1). Finally, tissue was collected from GK and Wistar rats for RNA extraction. Under euglycemia, GIP and GLP-1 stimulated the initial insulin response by 10-fold in GK rats (P < 0.05). At later hyperglycemia, the insulin response to GIP and GLP-1 was blunted to about one-third compared with controls (P < 0.05). In the bowel GLP-1 was about 2.6,16.7 times more potent than GIP in abolishing the migrating myoelectric complex in the GK and control rats. Polymerase chain reaction (PCR) showed GIP and GLP-1 receptor gene expression in pancreatic islets and in small bowel. The initially high, but later low insulin responsiveness to stimulation with GIP and GLP-1 along with inhibition of small bowel motility in the GK rat indicates a preserved incretin response on motility in diabetes type 2. [source] 11 Gastric myoelectric activity while viewing and eating food in obese participantsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006JY WANG Purpose:, This study observed the reactions of the stomach to food viewing and food eating in obese people. Method:, The participants were 20 obese (mean BMI of 32) and 20 normal-weighted (mean BMI of 21) undergraduate students, who were required to fast for at least 4 hours preceding the experiment. They viewed a video clip of food for 6 minutes; consumed food till full; and viewed the same video clip of food 30 minutes after the meal. Cutaneous electrogastrograms (EGGs) were recorded during the entire procedure. Questionnaires concerning the participants' perception of somatic and affective changes during the tasks were completed. Results:, The percentages of bradygastric, normal and tachygastric EGG activity were very similar between obese group and normal-weighted group during the baseline period. During the first food image viewing, an increase in normal 3 cpm activity and a decreased in bradygastric activity occurred in both groups, but obese participants showed less of an increase in 3 cpm activity than normal-weighted participants and the percentage of bradygastric activity was higher in obese group than in the normal-weighted group. During the 30 min. period following the meal, a higher percentage of bradygastric activity and a lower percentage of 3 cpm activity were observed in obese participants than in normal-weighted participants. Furthermore, obese participants showed a different pattern of change in 3 cpm and bradygastric activity than normal-weighed participants during the 30 min. The whole 30-min period was divided into five 6-min periods. In the obese group, the percentage of 3 cpm activity decreased in the third and forth 6-min periods and increased to the highest level in the last 6-min period, while in the normal-weighted group, the 3 cpm percentage was the greatest in the first 6-min period. Obese participants and normal-weighted participants reacted similarly to the second food image exposure, except that a higher increase in 3 cpm activity was observed in the normal-weighted group in the period after the termination of viewing the food images. Conclusions:, These data suggest that obese people react to food images and to food eating differently from normal-weighted people. EGG activity in obese participants needs further investigation. [source] | ||||||||||