High-resolution Mapping of Hyperglycemia-induced Gastric Slow Wave Dysrhythmias

BACKGROUND/AIMS: It is now recognised that gastric dysrhythmias are best characterised by their spatial propagation pattern. Hyperglycemia is an important cause of gastric slow wave dysrhythmia, however, the spatiotemporal patterns of dysrhythmias in this context have not been investigated. This study aims to investigate the relationship between hyperglycemia and the patterns of dysrhythmias by employing high-resolution (multi-electrode) mapping simultaneously at the anterior and posterior gastric serosa. METHODS: High-resolution mapping (8 × 16 electrodes per serosal) was performed in 4 anesthetized hounds. Baseline recordings (21 ± 8 minutes) were followed by intravenous injection of glucagon (0.5 mg per dose) and further recordings (59 ± 15 minutes). Blood glucose levels were monitored manually using a glucose sensing kit at regular 5-minute intervals. Slow wave activation maps, amplitudes, velocity, anisotropic ratio, and frequency were calculated. Differences were compared between baseline and post glucagon injection. RESULTS: Baseline slow waves propagated symmetrically and antegrade. The blood glucose levels were increased by an average of 112% compared to the baseline by the end of the recordings. All subjects demonstrated elevated incidence of slow wave dysrhythmias following injection compared to the baseline (48 ± 23% vs 6 ± 4%, P < 0.05). Dysrhythmias arose simultaneously or independently on anterior and posterior serosa. Spatial dysrhythmias occurred before and persisted after the onset and disappearance of temporal dysrhythmias. CONCLUSIONS: Infusion of glucagon induced gastric slow wave dysrhythmias, which occurred across a heterogeneous range of patterns and frequencies. The spatial dysrhythmias of gastric slow waves were shown to be more prevalent and persisted over a longer period of time compared to the temporal dysrhythmias.

Propagation Characteristics of Fasting Duodeno-Jejunal Contractions in Healthy Controls Measured by Clustered Closely-spaced Manometric Sensors

BACKGROUND/AIMS: High-resolution methods have advanced esophageal and anorectal manometry interpretation but are incompletely established for intestinal manometry. We characterized normal fasting duodeno-jejunal manometry parameters not measurable by standard techniques using clustered closely-spaced recordings. METHODS: Ten fasting recordings were performed in 8 healthy controls using catheters with 3–4 gastrointestinal manometry clusters with 1–2 cm channel spacing. Migrating motor complex phase III characteristics were quantified. Spatial-temporal contour plots measured propagation direction and velocity of individual contractions. Coupling was defined by pressure peak continuity within clusters. RESULTS: Twenty-three phase III complexes (11 antral, 12 intestinal origin) with 157 (95% CI, 104–211) minute periodicities, 6.99 (6.25–7.74) minute durations, 10.92 (10.68–11.16) cycle/minute frequencies, 73.6 (67.7–79.5) mmHg maximal amplitudes, and 4.20 (3.18–5.22) cm/minute propagation velocities were recorded. Coupling of individual contractions was 39.1% (32.1–46.1); 63.0% (54.4–71.6) of contractions were antegrade and 32.8% (24.1–41.5) were retrograde. Individual phase III contractions propagated > 35 fold faster (2.48 cm/sec; 95% CI, 2.25–2.71) than complexes themselves. Phase III complexes beyond the proximal jejunum were longer in duration (P = 0.025) and had poorer contractile coupling (P = 0.025) than proximal complexes. Coupling was greater with 1 cm channel spacing vs 2 cm (P < 0.001). CONCLUSIONS: Intestinal manometry using clustered closely-spaced pressure ports characterizes novel antegrade and retrograde propagation and coupling properties which degrade in more distal jejunal segments. Coupling is greater with more closely-spaced recordings. Applying similar methods to dysmotility syndromes will define the relevance of these methods.

Cutaneous Patches to Monitor Myoelectric Activity of the Gastrointestinal Tract in Postoperative Pediatric Patients / 대한소아소화기영양학회지

PURPOSE: Limited means exist to assess gastrointestinal activity in pediatric patients postoperatively. Recently, myoelectric gastrointestinal activity recorded by cutaneous patches has been shown in adult patients to be predictive of clinical return of gastrointestinal function postoperatively. The aim of this case series is to demonstrate the feasibility of this system in pediatric patients and to correlate myoelectric signals with return of bowel function clinically. METHODS: Pediatric patients undergoing abdominal surgery were recruited to have wireless patches placed on the abdomen within two hours postoperatively. Myoelectric data were transmitted wirelessly to a mobile device with a user-interface and forwarded to a cloud server where processing algorithms identified episodes of motor activity, quantified their parameters and nominally assigned them to specific gastrointestinal organs based on their frequencies. RESULTS: Three patients (ages 5 months, 4 year, 16 year) were recruited for this study. Multiple patches were placed on the older subjects, while the youngest had a single patch due to space limitations. Rhythmic signals of the stomach, small intestine, and colon could be identified in all three subjects. Patients showed gradual increase in myoelectric intestinal and colonic activity leading up to the first recorded bowel movement. CONCLUSION: Measuring myoelectric intestinal activity continuously using a wireless patch system is feasible in a wide age range of pediatric patients. The increase in activity over time correlated well with the patients' return of bowel function. More studies are planned to determine if this technology can predict return of bowel function or differentiate between physiologic ileus and pathologic conditions.

Chronic Intestinal Pseudo-obstruction: Clinical and Manometric Characteristics in the Chilean Population

BACKGROUND/AIMS: Chronic intestinal pseudo-obstruction (CIPO) is a rare syndrome characterized by a failure of the propulsion of intraluminal contents and recurrent symptoms of partial bowel obstruction in the absence of mechanical obstruction. Regional variations of the intestinal compromise have been described. Intestinal manometry can indicate the pathophysiology and prognosis. Our objective is to establish the demographic and clinical characteristics of group Chilean patients and analyze the motility of the small intestine and its prognostic value. METHODS: Patients with symptoms of intestinal pseudo-obstruction with dilated bowel loops were included, in all of whom a manometry of the small intestine was performed using perfused catheters. RESULTS: Of the 64 patients included, 51 women (average age 41.5 ± 17.6 years), 54 primary and 10 secondary CIPO were included. Dilatation of the small intestine was the only finding in 38 patients; in the remaining, the compromise was associated with other segments, primarily the colon. Forty-nine patients underwent 65 surgeries, mainly exploratory laparotomies and colectomies. Intestinal manometry was performed on all patients; 4 “patterns” were observed: neuropathic (n = 26), myopathic (n = 3), mixed (n = 24), and a group without motor activity (n = 11). The most relevant findings were the complex migrating motor disorders and decreased frequency and propagation of contractions. The 9 patients who died had a severe myopathic compromise. CONCLUSIONS: In our series, isolated small bowel compromise was the most common disorder. Neuropathic motor compromise was observed in most of the patients. Mortality was associated with severe myopathic compromise.

Migrating motor complex changes after side-to-side ileal bypass in mouse ileum ex-vivo: mechanism underlying the blind loop syndrome? / 대한외과학회지

PURPOSE: This study was intended to investigate the migrating motor complex (MMC) changes after ileal bypass in ex-vivo mouse models. METHODS: Partial (side-to-side) and total bypass (occlusion of proximal part of bypassed loop) were performed on ileums of female Institute of Cancer Research mice. After 2 and 4 weeks, the bypassed segments were harvested and MMCs were recorded at 4 different sites ex-vivo. Amplitude, duration, interval, direction of propagation, and the area under the curve (AUC) of MMCs were measured and compared to those of the controls. RESULTS: In control mice (n = 7), most MMCs propagated aborally (91.1%). After 2 weeks of partial bypass (n = 4), there was a significant decrease in both amplitude and AUC, and orally-propagating MMCs increased significantly (45%, P = 0.002). Bidirectional MMCs (originating in the bypassed loop and propagating in both directions) were also observed (10%). The amplitude of the MMCs remained decreased at 4 weeks after partial bypass (n = 4), and neither the AUC nor the direction of propagation showed significant changes compared to 2 weeks. Similarly, in the total bypass model, both the amplitude and AUC of the MMCs decreased significantly compared to controls. In contrast to partial bypass, 95% of the MMCs within the bypassed loop propagated aborally after 2 weeks (n = 6), which was similar to the control state. After 4 weeks (n = 5), however, MMCs either lost their temporal relationship or completely disappeared. CONCLUSION: The changes in propagation direction of the MMCs in the partially bypassed loop may contribute to stagnation of bowel contents and the development of blind loop syndrome.

Characteristics of phase 3-like activity and rebound excitation triggered by hexamethonium and atropine administration in the ovine small bowel.

Administration of hexamethonium (Hx) and atropine inhibits myoelectric and motor activity and then evokes a stimulatory effect called rebound excitation (RE) in the ovine small bowel. RE has not been precisely characterized so far and it is possible that it is composed of different types of motility. This study was thus devoted to characterizing these excitatory changes in the myoelectric and motor activity of the small bowel, particularly in the duodenum in conscious sheep. These alterations occurred in response to different intravenous doses of Hx and atropine administered alone or in combinations during various phases of the migrating myoelectric or motor complex (MMC) in the fasted and non-fasted sheep. Initially two basic types of excitatory response to the cholinergic blockade were found. In the course of chronic experiments different doses of Hx and atropine evoked phase 3-like activity (unorganized phase 3 of the MMC or its fragments) alternating with the less regular RE and the duration of these changes was related to the drug dose. In the non-fasted sheep these changes were less pronounced than in the fasted animals. When the drug was given during phase 1 of the MMC, RE did not occur or was greatly reduced. Administration of Hx and atropine in the course of phase 2a and phase 2b of the MMC produced roughly similar effects. Hx triggered stronger phase 3-like activity and RE than atropine. Combinations of Hx and atropine induced an additive effect, more evident in the fasted animals. These actions of Hx and atropine, thus, appear to involve at least partly the same intramural pathways. It is concluded that Hx and atropine evoke phase 3-like activity alternating with RE as the secondary stimulatory response in conscious sheep and both these types of the intestinal motility represent two distinct motility patterns.

A Preliminary Study on Gastric Electrical Activity in Patients with Gastrointestinal Stromal Tumor / 天津医药

Objects: To investigate the behavior of gastric electrical activity in patients with gastrointestinal stromal tumor(GIST) to identify the influences of GIST on the normal gastric electrical activity. Methods: The electrogastrogram (EGG) parameters of 27 patients with gastric GIST (GIST group) and 30 healthy volunteers (control group) were detected by the multi-channel electrogastrogram and the data were analyzed. Results: The values of postprandial mean frequency (MF), mean amplitude (MA) and the percentage of normal slow wave (N%) were increased, and the percentage of bradygastria (B%) was decreased than those of the fasting in control group(P 0.05). Compared with control group, the fasting MF and MA increased, the fasting N% of lead 1, 3, 4 and postprandial N% decreased, both percentages of fasting and postprandial tachygastria (T%) increased in GIST group (P < 0.01). The tachygastria incidence was significantly higher in GIST group than that of control (66.7% vs 3.3%, P <0.05). Conclusion: The gastric electrical activity was affected by the existence of GIST. The abnormal gastric electrical rhythm displayed mainly as tachygastria.

Effects of PYY on the interdigestive migrating myoelectric complex in the small intestine in vivo and the neural and endocrinal mechanisms of the effects / 药物分析学报

Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectrlc complex (MMC) in the small intestine in vivo and explore the neural and endecrinal mechanisms of the effects. Methods Spragne-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY, phentolamine, nitro-L-arginine (L-NNA, the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results At all the three recording points, PYY lengthened the drde length of MMC [from (591.90±128.98)s to (999.25±216.59)s, P<0. 01] and lowered the frequency of phase Ⅲ [from (39.28±8.40) min-1 to (22.08±3.13) min-1 , P<0.01], amplitude of phase Ⅲ [from (0. 320±0.060)mV to (0. 179±0.030)mV, P<0.01], and the portion of phase Ⅲ over the whole circle length [from (28. 61 ± 5.84)% to (15.43 ±5.16)% , P<0.01]. Phentolumine had no influence on the role of PYY. Administered L-NNA combined with PYY, the percentage of phase Ⅲ increased [(42. 09±8.67)%] compared with that of control(P<0.01) and compared with that of PYY administered alone (P<0. 01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY my inhibit the interdigestive intestine motility through the none-adrenergic none-choUnergic tract, while the m-receptor tract and circulating motilin are probably not involved In the depressing effect.

Effects of PYY on the interdigestive migrating myoelectric complex in the small intestine in vivo and the neural and endocrinal mechanisms of the effects / 西安交通大学学报·英文版

Objective: To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectric complex (MMC) in the small intestine in vivo and explore the neural and endocrinal mechanisms of the effects. Methods: Sprague-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY, phentolamine, nitro-L-arginine (L-NNA, the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results: At all the three recording points, PYY lengthened the circle length of MMC [from (591.90±128.98)s to (999.25±216.59)s, P<0.01] and lowered the frequency of phase III [from (39.28±8.40) min-1 to (22.08±3.13) min-1, P<0.01], amplitude of phase III [from (0.320±0.060)mV to (0.179±0.030)mV, P<0.01], and the portion of phase III over the whole circle length [from (28.61±5.84)% to (15.43±5.16)%, P<0.01]. Phentolamine had no influence on the role of PYY. Administered L-NNA combined with PYY, the percentage of phase III increased [(42.09±8.67)%] compared with that of control (P<0.01) and compared with that of PYY administered alone (P<0.01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY may inhibit the interdigestive intestine motility through the none-adrenergic none-cholinergic tract, while the α-receptor tract and circulating motilin are probably not involved in the depressing effect.

Effect of vincristine on the myoelectric activity and motility of the small intestine in rats / 中华消化杂志

Objective To investigate the effects of vincristine on myoelectric activity and motility of the small intestine in conscious rats and its mechanism. Methods Seventy-two SD rats were divided into six groups. The rats in control group were received 0.9% NaCl solution (n=18). The rats in group B were injected with vincristine and subdivided into 0.25 mg/kg(n=6) ,0.5 mg/kg(n=6)and 0.75 mg/kg groups. The group C and D was false operation (n=6)and false operation plus injection with 0.75 mg/kg of vincristine(n=6), respectively. The group E and F was subdiaphragmatic vagotomy plus 0.9% NaCl (n=6) or subdiaphragmatic vagotomy plus 0.75 mg/kg of vincristine (n=6), respectively. The myoelectric activity and motility of the small intestine were recorded. The frequency and area under the curve of slow wave, the periodicity of the migrating myoelectrie complex (MMC) and the duration of MMC Ⅲ were analyzed. The expressions of the myenteric neurons and interstitial cells of Cajal were evaluated by immunofluorescence stain. Results The myoelectric activity in 0.25mg/kg group was not different from the controls, but it changed in 0.5 mg/kg and 0.75 mg/kg groups which correlated with the time of vincristine injection. The irregular spike activity arose and accompanied with disruption of the MMC at (51±14.27) minutes,but recovered at (78.33±13.08) minutes. The periodicity was shorter in 0.5mg/kg [(343.17±142.93)s]and 0.75 mg/kg groups [(302.67±66.67)s] compared with controls [(740.22± 98.92) s, F=31.325, P<0.01]. Three days after vincristine administration, the area under the curve of slow wave decreased to (2.56±0.30) mV·s in 0.5 mg/kg group and (2.57±0.56) mV·s in 0.75 mg/kg group compared with the controls ((4.10±0.80) mV·s , F = 11.442, P<0.01). The intestinal propulsive rate was lower in 0.75 mg/kg group compared with the controls [(33.59±1.43) vs(60.34±2.41)%,t= 23.36, P<0.01]. The expression of the interstitial cells of Cajal was less than those in controls. Three days later, the area under the curve of slow wave in F group was less than that in controls. Conclusions Vincristine provokes alterations of myoelectric activity and motility of the small intestine. The early vincristine-induced escalating in myoelctric activity of the small intestine is through vagus nerve pathway. The decreased motility is contributed to the damage of the interstitial cells of Cajal.

A study on the mechanism of altered gastrointestinal motility in portal hypertensive rats / 中国普通外科杂志

Objective To evaluate the mechanism of altered gastrointestinal motility in portal hypertensive rats. Methods Thirty-two male Sprague-Dawley rats were divided into four groups:sham- operation control (SO, n=8), prehepatic portal hypertension by partial stenosis of the portal vein (PHPH, n=8 ), intrahepatic portal hypertension induced by injection of CCl 4 (IHPH, n=8), and intrahepatic portal hypertension with portacaval shunt (IHPH-PCS, n=8). Gastrointestinal myoelectrical activity and motility were monitored. Gastrointestinal hormones were measured with radioimmunoassay.Results Compared with SO rats, gastrointestinal motor index(MI) were reduced and abnormal myoelectrical activity were recorded (P

Effect of Pingwei Xiaodao Capsule on Gastric Motility of Functional Dyspepsia Model Rats / 中医杂志

Objective To observe the effect and mechanism of Pingwei Xiaodao Capsule (Capsule for functional dyspepsia) on the gastric motility of functional dyspepsia (FD) model rats.Methods Totally 60 wistar rats were randomized into a blank control group (normal group),model group,domperidone group,Pingwei Xiaodao Capsule large,medium,and small dosage groups.Except for the normal group,the rats of all other groups were irritated by clamping tails for making FD models.Then,the treatment was given for 7 days.The comparative observation was carried out on the gastric interdigestive myoelectric complex (IMC),slow wave frequency variation coefficient,abnormal rhythm index,and gastric emptying rate of all groups.Results Compared with the model group,the IMC period of domperidone group and all Pingwei Xiaodao Capsule groups was shortened,phase Ⅲ prolonged,incidence of phase Ⅲ increased(P