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.
Abdomen ; Adult ; Colon ; Electrophysiological Phenomena ; Gastrointestinal Tract ; Humans ; Ileus ; Intestinal Diseases ; Intestine, Small ; Motor Activity ; Myoelectric Complex, Migrating ; Stomach

BACKGROUND/AIMS: Interstitial cells of Cajal (ICC) and their special calcium-activated chloride channel, anoctamin-1 (ANO1) play pivotal roles in regulating colonic transit. This study is designed to investigate the role of ICC and the ANO1 channel in colonic transit disorder in dextran sodium sulfate (DSS)-treated colitis mice. METHODS: Colonic transit experiment, colonic migrating motor complexes (CMMCs), smooth muscle spontaneous contractile experiments, intracellular electrical recordings, western blotting analysis, and quantitative polymerase chain reaction were applied in this study. RESULTS: The mRNA and protein expressions of c-KIT and ANO1 channels were significantly decreased in the colons of DSS-colitis mice. The colonic artificial fecal-pellet transit experiment in vitro was significantly delayed in DSS-colitis mice. The CMMCs and smooth muscle spontaneous contractions were significantly decreased by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), an ANO1 channel blocker, and NG-Nitro-L-arginine methyl ester hydrochloride (L-NAME), an inhibitor of nitric oxide synthase activity, in DSS-colitis mice compared with that of control mice. Intracellular electrical recordings showed that the amplitude of NPPB-induced hyperpolarization was more positive in DSS-colitis mice. The electric field stimulation-elicited nitric-dependent slow inhibitory junctional potentials were also more positive in DSS-colitis mice than those of control mice. CONCLUSION: The results suggest that colonic transit disorder is mediated via downregulation of the nitric oxide/ICC/ANO1 signalling pathway in DSS-colitis mice.
Animals ; Blotting, Western ; Chloride Channels ; Colitis ; Colon ; Dextrans ; Down-Regulation ; In Vitro Techniques ; Interstitial Cells of Cajal ; Mice ; Muscle, Smooth ; Myoelectric Complex, Migrating ; NG-Nitroarginine Methyl Ester ; Nitric Oxide Synthase ; Polymerase Chain Reaction ; RNA, Messenger ; Sodium

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.
Blood Glucose ; Electrodes ; Electrophysiology ; Gastrointestinal Tract ; Glucagon ; Glucose ; Hyperglycemia ; Incidence ; Injections, Intravenous ; Interstitial Cells of Cajal ; Myoelectric Complex, Migrating ; Serous Membrane

BACKGROUND/AIMS: Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. METHODS: Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca²⁺-activated Cl⁻ (Ano1) channels, and small conductance Ca²⁺- activated K⁺ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. RESULTS: PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. CONCLUSIONS: Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα⁺) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility.
Abdomen ; Animals ; Apamin ; Blotting, Western ; Chloride Channels ; Colon ; Down-Regulation ; Feces ; Interstitial Cells of Cajal ; Mice ; Muscle, Smooth ; Myoelectric Complex, Migrating ; Nitric Oxide Synthase ; Platelet-Derived Growth Factor ; Silicon ; Silicones ; Small-Conductance Calcium-Activated Potassium Channels ; Up-Regulation

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.
Catheters ; Fasting ; Intestines ; Jejunum ; Manometry ; Muscle Contraction ; Myoelectric Complex, Migrating ; Periodicity

Researches on microbiota in the stomach have entered a revolutionary period in recent years due to the advanced technology that can detect culture-independent gastric microfloras. In spite of its harsh environment, stomach plays a role as an ecosystem for some microbiota. Their composition and number of colony forming units are influenced by several innate defense mechanisms such as low gastric pH, gastric mucus layer, migrating motor complex and some external factors such as gastric acid lowering medications and diet patterns. Here, we review the literatures concerning factors that influence the gastric microbiota.We believe this will be helpful for understanding the role of microbiota in the stomach.
Defense Mechanisms ; Diet ; Ecosystem ; Gastric Acid ; Gastric Juice ; Hydrogen-Ion Concentration ; Microbiota* ; Mucus ; Myoelectric Complex, Migrating ; Proton Pump Inhibitors ; Stem Cells ; Stomach

BACKGROUND/AIMS: Postprandial symptoms of fullness and abdominal discomfort are common after fatty meals. Gastric lipases hydrolyze 10% to 20% of dietary triglycerides during the stomach trituration period of digestion. The aim of this study was to evaluate the effects of acid-resistant lipase on upper gastrointestinal symptoms, including fullness and bloating, as well as on gastric myoelectrical activity after healthy subjects ingested a high-fat, liquid meal. METHODS: This study utilized a double-blind, placebo-controlled, crossover design with 16 healthy volunteers who ingested either a capsule containing 280 mg of acid-resistant lipase or a placebo immediately before a fatty meal (355 calories, 55% fat). Participants rated their stomach fullness, bloating, and nausea before and at timed intervals for 60 minutes after the meal. Electrogastrograms were obtained to assess the gastric myoelectrical activity. RESULTS: Stomach fullness, bloating, and nausea increased significantly 10 minutes after ingestion of the fatty meal (p<0.01), whereas normal gastric myoelectrical activity decreased and tachygastria increased (p<0.05). With lipase, reports of stomach fullness were significantly lower compared with placebo (p<0.05), but no effect on gastric myoelectrical activity or other upper gastrointestinal symptoms was observed. CONCLUSIONS: The high-fat meal induced transient fullness, bloating, nausea, and tachygastria in healthy individuals, consistent with post-prandial distress syndrome. Acid-resistant lipase supplementation significantly decreased stomach fullness.
Abdominal Pain/etiology/psychology ; Adult ; Cross-Over Studies ; Diet, High-Fat/*adverse effects/psychology ; *Dietary Supplements ; Double-Blind Method ; Dyspepsia/etiology/*prevention & control/psychology ; Female ; Gastrointestinal Motility/drug effects/physiology ; Healthy Volunteers ; Humans ; Lipase/*administration & dosage ; Male ; Meals ; Middle Aged ; Myoelectric Complex, Migrating ; Nausea/etiology/psychology ; Postprandial Period ; Stomach/*drug effects/physiology ; Young Adult

Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, NW-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.
Atropine ; Enteric Nervous System ; Humans* ; Ileum ; Immunohistochemistry ; Membrane Potentials ; Microelectrodes ; Muscle, Smooth ; Myoelectric Complex, Migrating ; Nitroprusside

OBJECTIVETo observe the effects of acupuncture at "Tianshu" (ST 25) on electro-activity and mechanical motility at different phases of migrating motor complex (MMC) during jejunal digestion period in rats with detached jejunum, so as to explore the effect and mechanism of acupuncture on regulating intestinal movement.

METHODSSixteen adult SD rats were selected. Electrodes were implanted in the serous membrane of intestinal smooth muscl.e and high-sensitivity sensors of strain gauge were sutured on serosal surface, and then the rat was anesthetized and its jejunum was detached. Electro-acriviry and mechanical motility of jejunal smooth muscle were recorded simultaneously. Acupuncture was applied at "Tianshu" (ST 25) at MMC I , MMCII and MMC III, respectively, to observe its influence on electro-activity and mechanical motility.

RESULTSAt phase of MMC I, there was no obvious change of the fast wave before and after the acupuncture, while the frequency and amplitude of slow wave and mechanical motility were both significantly decreased compared with baseline (P < 0.01). At MMCII-Ill, the frequency and amplitude of fast wave, slow wave and motility were all significantly decreased compared with baseline (P < 0.01). Acupuncture at "Tianshu" (ST 25) had prohibited effects on electro-activity and mechanical motility of jejunal smooth muscle in rats with detached jejunum.

CONCLUSIONAcupuncture at "Tianshu" (ST 25) has obvious prohibited effects on electro-acrivity and mechanical motility at MMC I , MMC II and MMC III time phases in rats with detached jejunum. The possible mechanism is that acupuncture at "Tianshu" (ST 25) could prohibit jejunum movement through reflex path of skin-sympathetic.

Acupuncture Points ; Acupuncture Therapy ; Animals ; Digestion ; Electrophysiological Phenomena ; Gastrointestinal Diseases ; physiopathology ; therapy ; Humans ; Jejunum ; chemistry ; physiology ; Male ; Myoelectric Complex, Migrating ; Rats ; Rats, Sprague-Dawley

The colonic migrating motor complex (CMMC) is a critical neurally mediated rhythmic propulsive contraction observed in the large intestine of many mammals. It seems to be equivalent to the high amplitude propagating contractions (HAPCs) in humans. This review focuses on the probable neural mechanisms involved in producing the CMMC or HAPC, their likely dependence on mucosal and neuronal serotonin and pacemaker insterstitial cells of Cajal networks and how intrinsic neural reflexes affect them. Discussed is the possibility that myenteric 5-hydroxytryptamine (5-HT) neurons are not only involved in tonic inhibition of the colon, but are also involved in generating the CMMC and modulation of the entire enteric nervous system, including coupling motility to secretion and blood flow. Mucosal 5-HT appears to be important for the initiation and effective propagation of CMMCs, although this mechanism is a longstanding controversy since the 1950s, which we will address. We argue that the slow apparent propagation of the CMMC/HAPC down the colon is unlikely to result from a slowly conducting wave front of neural activity, but more likely because of an interaction between ascending excitatory and descending (serotonergic) inhibitory neural pathways interacting both within the myenteric plexus and at the level of the muscle. That is, CMMC/HAPC propagation appears to be similar to esophageal peristalsis. The suppression of inhibitory (neuronal nitric oxide synthase) motor neurons and mucosal 5-HT release by an upregulation of prostaglandins has important implications in a number of gastrointestinal disorders, especially slow transit constipation.
Colon* ; Constipation ; Enteric Nervous System ; Humans ; Intestine, Large ; Mammals ; Motor Neurons ; Mucous Membrane ; Myenteric Plexus ; Myoelectric Complex, Migrating* ; Neural Pathways ; Neurons* ; Nitric Oxide ; Peristalsis ; Prostaglandins ; Reflex* ; Serotonin* ; Up-Regulation