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Introduction: Before tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance. Methods: Patients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30–60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum's cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial. Results: Pre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1–458.1 [159.8–552.9]) mmHg and 358.9 (274.0–413.3 [129.0–539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6–428.7 [73.9–522.1]) mmHg and 258.3 (162.5–347.5 [56.0–481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9–411.4 [60.5–492.4]) mmHg and 149.8 (87.0–246.6 [51.2–447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4–557.9 [129.0–991.2]) mm2 and 386.8 (292.0–537.3 [88.3–1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7–618.4 [161.6–988.1]) mm2 and 385.6 (306.3–562.0 [105.5–922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%). Conclusions: Compared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out. Trial registration: This trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192). [ABSTRACT FROM AUTHOR]

Purpose: The combined effects of grain digestibility and dietary fibre on digesta passage rate and satiety in humans are poorly understood. Satiety can be increased through gastric distention, reduced gastric emptying rate and when partially digested nutrients reach the terminal ileum to stimulate peptide release through the ileal/colonic brakes to slow the rate of digesta passage. This study determined the effects of grain digestibility and insoluble fibre on mean retention time (MRT) of digesta from mouth-to-ileum, feed intake (FI), starch digestion to the terminal ileum and faecal short chain fatty acids (SCFA) in a pig model. Method: Twelve grain-based [milled sorghum (MS), steam-flaked-sorghum, milled wheat, and steam-flaked-wheat (SFW)] diets with different intrinsic rates of starch digestion, assessed by apparent amylase diffusion coefficient (ADC), and fibre from oat hulls (OH) at 0, 5 and 20% of the diet were fed to ileal-cannulated pigs. Result: MRT was affected by grain-type/processing (P < 0.05) and fibre amount (P < 0.05). An approximate tenfold increase in ADC showed a limited decline in MRT (P = 0.18). OH at 20% increased MRT (P < 0.05) and reduced FI (P < 0.05). Ileal digestibility of starch increased and faecal SCFA concentration decreased with ADC; values for MS being lower (P < 0.001) and higher (P < 0.05), respectively, than for SFW. Conclusions: Lower ileal digestibility of starch, higher faecal SCFA concentration and longer MRT of MS than SFW, suggest the ileal/colonic brakes may be operating. FI appeared to decrease with increasing MRT. MRT increased and intake decreased with grain-based foods/feeds that have low starch digestibility and substantial amounts of insoluble fibre. [ABSTRACT FROM AUTHOR]

Background: Gastric emptying scintigraphy is widely used in infants and children, but there is a lack of age-specific normative data.Objective: The objectives of this retrospective study were: 1) to establish a range of gastric emptying of milk or formula as a surrogate for normal gastric emptying in infants and young children ≤5 years of age, and 2) to investigate the effects of patient age, feeding volume, feeding route and gastroesophageal reflux on gastric emptying.Materials and Methods: The reports of 5,136 gastric emptying studies of children ≤5 years of age performed at Children's National Medical Center from January 1990 to August 2012 were reviewed. Demographic data, 1-h and 3-h gastric emptying values and gastroesophageal reflux status of all patients were stored in a database. Using stringent inclusion and exclusion criteria, the studies of patients as similar to healthy children as possible were selected for this study.Results: The study group included 2,273 children (57% male) ages 0-59 months (median: 4.6 months). The median 1-h gastric emptying was 43% (interquartile range [IQR] 34-54%). The median 3-h gastric emptying was 91% (IQR 79-98%). Sixty-one percent of patients with 1-h gastric emptying value of <50% had 3-h gastric emptying ≥80%. Gastric emptying was significantly faster in children ≤6 months as compared with all older age groups. In each age group, the median gastric emptying decreased with increasing feeding volume. Gastric emptying was significantly faster in patients fed via combined nasogastric tube and oral routes as compared with those fed exclusively orally. There was no significant difference in gastric emptying of children with and without gastroesophageal reflux.Conclusion: Although there are statistically significant differences in gastric emptying based on age, volume and route of feeding, the data suggest that overall normal liquid gastric emptying in infants and children ≤5 years of age is ≥80% at 3 h. One-hour emptying measurements are not reliable for detecting delayed gastric emptying. [ABSTRACT FROM AUTHOR]

There is a growing search for less invasive methods while studying the diet of Antarctic animals in the wild. Therefore, we compared the diet of gentoo penguins from stomach contents (i.e. through visual identification of prey remains) and scats (i.e. faeces), and further compared prey DNA assay in fresh and old scats. Prey remains identified visually in stomach contents and scats were broadly comparable: the crustaceans and fish were the most important components, with Themisto gaudichaudii clearly being the most frequent and numerous prey species in both sampling methods. By mass, differences in species frequency were observed in stomach contents (Parachaenichthys georgianus) and scats (Champsocephalus gunnari), with the former fish species absent in scats. Differences were detected in the most frequent prey (T. gaudichaudii and Euphausia superba) and in various fish species, most with bigger sizes in scats. Allometric equations to estimate most crustacean’s sizes (i.e. relationships between carapace and mass/total length) are needed. For DNA studies, when comparing DNA from fresh and old scats, both provided similar results that, in general, were also similar to the visual analysis. In order to use penguin scats (along with the use of DNA analyses) for monitoring purposes, allometric equations to estimate mass and size of prey (most crustaceans) and better designed species-specific primers are needed for targeting key prey species (e.g. Euphausia superba, T. gaudichaudii). These DNA methodologies can complement other methods (i.e. visual analyses and stomach contents analyses) in monitoring programs of penguins. [ABSTRACT FROM AUTHOR]

The arterial system of the gastrointestinal tract has many variations. However, variation in the inferior mesenteric artery (IMA) is less common than for the other abdominal arteries. The case in the present cadaver subject showed a variation in the anatomy of the IMA that differed from those seen in previous studies, because it did not originate from the abdominal aorta and had no branches. A single artery arising from branches of the inferior pancreaticoduodenal and middle colic arteries supplied the hindgut. This variation generated blood vessels along the digestive tract during the later stages of development. The marginal artery of the colon in this case probably was more highly developed instead of the IMA. It is clinically important to know the range of variations, as these data are used in the diagnosis and treatment of abdominal diseases. This hitherto unknown variation might affect the health of patients, and we recommend radiographic examinations for diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Background: We recently demonstrated that cascade stomach detected by barium studies was correlated with upper gastrointestinal symptoms. We developed a new endoscopic classification of cascade stomach and examined its relationship with reflux esophagitis.Methods: Study 1: the classification (grades 0-3) was based on detecting a ridge that runs from the cardia toward the anterior wall crossing the greater curvature. Inter-observer variation was evaluated by kappa statistics when ten experienced endoscopists used this classification three times each. Study 2: in 710 consecutive subjects (500 men and 210 women) undergoing endoscopic screening, the grade of cascade stomach and incidence of reflux esophagitis were compared.Results: In study 1, the kappa values at the third assessment were 0.85, 0.58, 0.50, and 0.78 for each grade, respectively, while overall agreement was 0.68. In study 2, the incidence of reflux esophagitis in men was 20 % in grade 0, 17 % in grade 1, 25 % in grade 2, and 30 % in grade 3, showing significant differences. Among women, the incidence of reflux esophagitis in each grade was 9, 3, 6, and 35 %, respectively, also showing significant differences. Multivariate analysis showed that independent risk factors for reflux esophagitis were cascade stomach (odds ratio = 2.20), body mass index, and hiatus hernia in men, as well as cascade stomach (odds ratio = 9.01) and smoking tobacco in women.Conclusions: This endoscopic classification of cascade stomach showed acceptable inter-observer variation. Cascade stomach is a risk factor for reflux esophagitis. [ABSTRACT FROM AUTHOR]

Background: Gastric slow waves regulate peristalsis, and gastric dysrhythmias have been implicated in functional motility disorders. To accurately define slow wave patterns, it is currently necessary to collect high-resolution serosal recordings during open surgery. We therefore developed a novel gastric slow wave mapping device for use during laparoscopic procedures.Methods: The device consists of a retractable catheter constructed of a flexible nitinol core coated with Pebax. Once deployed through a 5-mm laparoscopic port, the spiral head is revealed with 32 electrodes at 5 mm intervals. Recordings were validated against a reference electrode array in pigs and tested in a human patient.Results: Recordings from the device and a reference array in pigs were identical in frequency (2.6 cycles per minute; p = 0.91), and activation patterns and velocities were consistent (8.9 ± 0.2 vs 8.7 ± 0.1 mm s-1; p = 0.2). Device and reference amplitudes were comparable (1.3 ± 0.1 vs 1.4 ± 0.1 mV; p = 0.4), though the device signal-to-noise ratio was higher (17.5 ± 0.6 vs 12.8 ± 0.6 dB; P < 0.0001). In the human patient, corpus slow waves were recorded and mapped (frequency 2.7 ± 0.03 cycles per minute, amplitude 0.8 ± 0.4 mV, velocity 2.3 ± 0.9 mm s-1).Conclusion: In conclusion, the novel laparoscopic device achieves high-quality serosal slow wave recordings. It can be used for laparoscopic diagnostic studies to document slow wave patterns in patients with gastric motility disorders. [ABSTRACT FROM AUTHOR]

Background: Gastric food residue frequently is observed on endoscopy despite fasting.Aims: To delineate factors promoting endoscopic food retention in the stomach.Methods: Two series of analyses were performed. Magnitudes of retained food in 834 patients from an endoscopy database were related to obstructive versus non-obstructive etiologies and gastric emptying findings. Emptying delays in 619 patients from a scintigraphy database were associated with endoscopic food retention, gastroparesis etiologies, and medications that modify gastric transit.Results: On endoscopy, 310 (37 %) had large, 338 (41 %) showed medium, and 103 (12 %) exhibited small amounts of retained food in the stomach. Of 433 patients with definable etiologies of food retention, 106 (24 %) had obstructive causes. One hundred three of 327 (31 %) with non-obstructive conditions underwent scintigraphy showing mean 52 ± 29 % 4-h retention. From the scintigraphy database, 164/619 patients (26 %) with delayed emptying exhibited food retention on endoscopy. Four-hour scintigraphic retention was greater with versus without retained food (41 ± 25 vs. 32 ± 22 %, P < 0.001). Retained food occurred more frequently with postsurgical (28/69, 41 %) versus diabetic (33/139, 24 %) and idiopathic (65/294, 22 %) gastroparesis (P = 0.006). Opiate use was more prevalent with increasing food retention (P = 0.02), while other medications that delay or accelerate emptying did not relate to retained food.Conclusions: Gastric food retention has obstructive and non-obstructive causes, and is found in one-quarter of gastroparesis, especially postsurgical cases. Gastric emptying delays correlate with amounts of retained food on endoscopy. Retention is influenced by opiates, but not other medications. These analyses delineate pathogenic factors promoting gastric food retention. [ABSTRACT FROM AUTHOR]

In Japan, the first half of the twentieth century saw a remarkable revival of concern with the cultivation of the belly, with a variety of belly-cultivation techniques, particularly breathing exercise and meditative sitting, widely practiced for improving health and treating diseases. This article carefully examines some practitioners' experiences of belly-cultivation practice in attempting to understand its healing effects for them within their life histories and contemporary intellectual, social and cultural contexts. It shows that belly-cultivation practice served as a medium for some practitioners to reflect on and retell their life stories, and that the personal charisma of certain masters and the communities developing around them provided practitioners with a valuable sense of belonging in an increasingly industrialized and urbanized society. Moreover, these belly-cultivation techniques provided an embodied way for some to explore and affirm their sense of self and develop individual identity. While they were increasingly promoted as cultural traditions capable of cultivating national character, they also served as healing practices by inspiring practitioners with a sense of collective identity and purpose. With these analyses, this article sheds light on the complicated meanings of belly-cultivation for practitioners, and provides illustrative examples of the multitude of meanings of the body, bodily cultivation and healing. [ABSTRACT FROM AUTHOR]

Background: Gastric acidification inhibits motilin-induced gastric phase III contractions. However, the underlying mechanism has not been thoroughly investigated. Here, we studied the inhibitory mechanism by gastric acidification on motilin-induced contraction in Suncus murinus (S. murinus).Methods: We measured interdigestive gastric phase III contractions in conscious, freely moving S. murinus, and examined the inhibitory effect of gastric acidification on motilin action and the involvement of the vagus nerve and transient receptor potential vanilloid receptor 1 (TRPV1) in the inhibitory mechanism.Results: A bolus injection of motilin evoked phase III-like contractions during intravenous infusion of saline. Intragastric acidification (pH 1.5-2.5) inhibited motilin-induced phase III contractions in a pH-dependent manner and significantly decreased the motility index at a pH below 2.0. In contrast, intraduodenal acidification (pH 2.0) failed to inhibit motilin-induced contractions. Vagotomy significantly alleviated the suppression of motilin-induced gastric contractions under acidic conditions (pH 2.0), suggesting vagus nerve involvement. Moreover, intragastric acidification (pH 2.0) significantly increased the number of c-Fos-positive cells in the nucleus tractus solitarii. In vagotomized S. murinus, the number of c-Fos-positive cells did not change, even under gastric acidification conditions. TRPV1 mRNA was highly expressed in the muscle and mucosal regions of the antrum and the nodose ganglion, whereas was not detected in the upper small intestine. Capsazepin, a TRPV1 antagonist, completely rescued the inhibitory effect of gastric acidification.Conclusions: Gastric acidification in S. murinus inhibits motilin-induced contractions, a finding similar to results observed in humans, while TRPV1-expressing vagus nerves play a role in the inhibitory mechanism. [ABSTRACT FROM AUTHOR]

Background: An optimal reconstruction method for proximal gastrectomy (PG) remains elusive. Esophagogastrostomy (EG) is technically simple but suffers from the disadvantage of gastroesophageal reflux. Jejunal interposition (JI) has a low rate of gastroesophageal reflux, but the procedure is more complicated, and delayed gastric emptying is a problem. Methods: We created a modified EG and have used the modified technique for PG since 2006. The procedure involves shaping the remnant stomach into a gastric conduit. The EG is performed high on the anterior wall, and the conduit is kept straight by applying a circular stapler inserted from the anterior wall of the antrum. The tip of the gastric conduit is then inserted into the lower mediastinum, creating a sharp angle of His. In this retrospective cohort study, the clinical and physiological outcomes were compared between 25 patients who underwent this procedure and 21 patients who underwent JI from 2001 to 2005. Results: Laparoscopic procedures were performed more frequently, and residual food and bile reflux were less common in the EG group than in the JI group. No significant differences in remnant gastritis or reflux esophagitis were observed between the two groups. However, the late complication of intestinal obstruction occurred only in the JI group. Conclusions: The modified EG technique has advantages over the JI technique because of its simplicity and low incidence of residual food and bile reflux. The next step would be to explore this technique further by a prospective multi-institutional study to confirm the reproducibility of its benefits. Miniabstract: The modified EG technique has advantages over the JI technique because of its simplicity, high rate of laparoscopy use, and low incidence of gastroesophageal reflux. [ABSTRACT FROM AUTHOR]

Microplastic particles (MP) contaminate oceans and affect marine organisms in several ways. Ingestion combined with food intake is generally reported. However, data interpretation often is circumvented by the difficulty to separate MP from bulk samples. Visual examination often is used as one or the only step to sort these particles. However, color, size, and shape are insufficient and often unreliable criteria. We present an extraction method based on hypochlorite digestion and isolation of MP from the membrane by sonication. The protocol is especially well adapted to a subsequent analysis by Raman spectroscopy. The method avoids fluorescence problems, allowing better identification of anthropogenic particles (AP) from stomach contents of fish by Raman spectroscopy. It was developed with commercial samples of microplastics and cotton along with stomach contents from three different Clupeiformes fishes: Clupea harengus, Sardina pilchardus, and Engraulis encrasicolus. The optimized digestion and isolation protocol showed no visible impact on microplastics and cotton particles while the Raman spectroscopic spectrum allowed the precise identification of microplastics and textile fibers. Thirty-five particles were isolated from nine fish stomach contents. Raman analysis has confirmed 11 microplastics and 13 fibers mainly made of cellulose or lignin. Some particles were not completely identified but contained artificial dyes. The novel approach developed in this manuscript should help to assess the presence, quantity, and composition of AP in planktivorous fish stomachs. [ABSTRACT FROM AUTHOR]

Venules in the stomach may have intrinsic properties for maintaining active microcirculation drainage even during gastric filling. Properties of spontaneous and nerve-mediated activity of submucosal venules in the rat stomach were investigated. Changes in vasodiameter and intracellular Ca in venular smooth muscle cells (SMCs) were monitored by video tracking and Fluo-8 Ca imaging, respectively. Venular SMCs developed synchronous spontaneous Ca transients and corresponding rhythmic constrictions of the venules. Nominally Ca-free solution or an L-type Ca channel blocker (1 μM nifedipine) disrupted the Ca transient synchrony and abolished spontaneous constrictions. Spontaneous constrictions were also prevented by inhibitors of sarcoplasmic reticulum Ca-ATPase (10 μM cyclopiazonic acid (CPA)), IP receptors (100 μM 2-APB) or Ca-activated Cl channels (100 μM niflumic acid). Transmural nerve stimulation (TNS) induced a long-lasting venular constriction that was abolished by α-adrenoceptor antagonist (1 μM phentolamine), while TNS evoked a sympathetic transient constriction of arterioles that was abolished by a combination of phentolamine and a P2 purinoceptor antagonist (10 μM pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS)). Consistently, P2X purinoceptor immunoreactivity was detected in arteriolar but not venular SMCs. Primary afferent nerve stimulation (300 nM capsaicin) caused a venular dilatation by releasing calcitonin gene-related peptide. Thus, Ca release from the sarcoplasmic reticulum may play a fundamental role in the generation of spontaneous Ca transients, while electrical coupling amongst venular SMCs via L-type Ca channel activation appears to be critical for Ca transient synchrony as well as spontaneous contractions. Sympathetic venular constrictions appear to be exclusively mediated by noradrenaline due to the lack of P2X receptor in venular SMCs. [ABSTRACT FROM AUTHOR]

The gut microbiota plays a crucial role in the maturation of the intestinal mucosal immune system of its host. Within the thousand bacterial species present in the intestine, the symbiont segmented filamentous bacterium (SFB) is unique in its ability to potently stimulate the post-natal maturation of the B- and T-cell compartments and induce a striking increase in the small-intestinal Th17 responses. Unlike other commensals, SFB intimately attaches to absorptive epithelial cells in the ileum and cells overlying Peyer's patches. This colonization does not result in pathology; rather, it protects the host from pathogens. Yet, little is known about the SFB-host interaction that underlies the important immunostimulatory properties of SFB, because SFB have resisted in vitro culturing for more than 50 years. Here we grow mouse SFB outside their host in an SFB-host cell co-culturing system. Single-celled SFB isolated from monocolonized mice undergo filamentation, segmentation, and differentiation to release viable infectious particles, the intracellular offspring, which can colonize mice to induce signature immune responses. In vitro, intracellular offspring can attach to mouse and human host cells and recruit actin. In addition, SFB can potently stimulate the upregulation of host innate defence genes, inflammatory cytokines, and chemokines. In vitro culturing thereby mimics the in vivo niche, provides new insights into SFB growth requirements and their immunostimulatory potential, and makes possible the investigation of the complex developmental stages of SFB and the detailed dissection of the unique SFB-host interaction at the cellular and molecular levels. [ABSTRACT FROM AUTHOR]

Third-stage larvae of the anisakid nematode Contracaecum osculatum were recovered from livers of Atlantic cod ( Gadus morhua) caught in the Baltic Sea (June 2014) and used for experimental infection of two pigs (one male and one female). Each pig received 215 larvae by oral infection (feeding with minced cod liver containing live nematode larvae). Pigs were euthanized after 5 days, necropsied, and subjected to parasitological investigation. A total of 12 larvae were found penetrating the mucosa of the ventricle (7 in the female pig and 5 in the male pig) eliciting a granulomatous reaction at the penetration site. Four non-attached larvae were found in the female pig stomach and one in the male pig. Petechial bleeding was observed at several locations in the ventricular mucosa where larvae were located. Histological examination of the stomach mucosa revealed a massive cellular infiltration (giant cells, lymphocytes, macrophages, granulocytes, and fibroblast like cells) around the penetrating larva. Mononuclear and polymorphonuclear cells containing eosinophilic granulae were particularly prominent in the granulomas. Reactions correspond to reactions in pigs following experimental infection with the human pathogenic anisakid larvae Anisakis sp. and Pseudoterranova sp. which suggests that C. osculatum might have a zoonotic potential as well. [ABSTRACT FROM AUTHOR]

We studied the effect of sodium hydrosulfite (NaHS), a donor of hydrogen sulfide (HS), on spontaneous contractive activity of isolated preparations of rat stomach and jejunum under isometric conditions. NaHS in concentrations of 10-200 μM reduced the amplitude, tonic tension, and frequency of contractions of the preparations. Blockade of K channels with a non-specific antagonist tetraethylammonium (10 mM) increased contraction amplitude in the stomach strip and jejunum segment. The effects of NaHS on all parameters of contractile activity of the stomach and jejunum were fully preserved against the background of tetraethylammonium application. These data suggest that HS in physiologically relevant concentrations inhibited spontaneous contractile activity of smooth muscle cells in rat stomach and jejunum by reducing the amplitude and frequency of contractions and decreased tonic tension without affecting the function of voltage- and calcium-dependent K channels. [ABSTRACT FROM AUTHOR]

The ontogeny of diving and foraging behavior of northern fur seal pups from a stable population on Bering Island, Russia, was recorded with animal-borne instruments during their first few months at sea, a critical period during their first year at sea. Thirty-five pups were instrumented with satellite-linked time-depth recorders and stomach temperature pills. Diving occurred predominantly at night with deeper and longer dives as the pups matured. Mean dive depths were correlated with lunar illumination, whereas mean dive durations were also correlated with time of day and sex. Foraging success did not differ between sexes, and there was no relationship between meal size (as indicated by feeding event duration and minimum stomach temperature) and lunar illumination fraction or maximum foraging depth. Although most pups were able to successfully forage within 3 days of starting their migration, the number of feeding events recorded each day remained low (mean 1.6 events day). There was no indication of an appreciable increase in meal size after the first 2 weeks of the migration despite an increase in dive frequency and depth. The results are consistent with observations that pups do not gain mass during their first year and emphasize the risk of starvation from infrequent foraging in cold water. [ABSTRACT FROM AUTHOR]

Background: Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R) and a peptide hormone that promotes food intake and gastric motility. Our aims are to explore the effects of ghrelin on gastric distension (GD) sensitive neurons in the lateral septum, and the possible regulation of gastric motility by ghrelin through the hypothalamic arcuate nucleus (ARC). Methods: Single-unit discharges were recorded, extracellularly, and the gastric motility was monitored by the administration of ghrelin in the lateral septum. The projection of nerve fiber and expression of ghrelin were observed by retrograde tracer and fluo-immunohistochemistry staining. The expression of GHS-R and ghrelin was determined by real-time polymerase chain reaction and western blotting analysis. Results: There were GD neurons in the lateral septum. The administration of ghrelin could excite both GD-excitatory (GD-E) and GD-inhibitory (GD-I) neurons in the lateral septum. Gastric motility was significantly enhanced by the administration of ghrelin in the lateral septum in a dose-dependent manner. Pretreatment with [ d-Lys-3]-GHRP-6, however, could completely abolish the ghrelin-induced effects. Electrical stimulation of the ARC could significantly excite the response of GD neurons to ghrelin, increase ghrelin protein expression in the lateral septum and promote gastric motility. Nevertheless, these effects could be mitigated by pretreatment of [ d-Lys-3]-GHRP-6. Electrical lesion of the lateral septum resulted in decreased gastric motility. The GHS-R and Ghrelin/FG-double labeled neurons were observed in the lateral septum and ARC, respectively. Conclusions: It is suggested that the lateral septum may receive afferent information from the gastrointestinal tract and promote gastric motility. Ghrelin plays an important role in promoting gastric motility in the lateral septum. The ARC may be involved in the regulation of the lateral septum's influence on gastric motility. [ABSTRACT FROM AUTHOR]

Pacemaker cells of the upper portion of the digestive tract were studied by electromyography of various parts of the stomach and duodenum. Pacemaker cells of the stomach were located mainly at the interface between the lesser curvature and cardia and in the proximal part of the antrum and were characterized by high spontaneous slow-wave and spike activities. Antroduodenal coordination contributes to sequential motor activity of the stomach and duodenum. Pacemaker cells were characterized by a specific shape and a lesser number of myofibrils. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of gum chewing on recovery of bowel function after cesarean section. Methods: Fifty pregnant women who underwent cesarean section at Chiang Mai University hospital from September 2010 to December 2010 were recruited. After cesarean section, patients were randomized into two groups. In group 1 (conventional), patients were fed according to conventional feeding protocol without gum chewing. For group 2 (gum chewing), patients were asked to chew two pieces of sugarless gum for 30 min in the morning, noon, evening and bedtime until the first flatus, along with conventional postoperative feeding protocol. Categorical variables were analyzed using the Chi-square or Fischer's exact test, as appropriate. For continuous variables with skewed distribution, the Mann-Whitney U test was employed. Results: There were 25 patients in each group. Median time to the first flatus was shorter in the gum chewing group (36.37 vs. 41.33 h, P = 0.02). Also, there was a trend toward less abdominal cramping on days 1 and 2 in the gum chewing group. However, no difference in other outcome measures of bowel function recovery and ileus-related complications between the groups could be demonstrated. Approximately three-fourth of the women in each group had good tolerance to their first meal. Hospital stay and participants' satisfaction to the assigned feeding schedules were comparable between the study groups. Conclusion: Gum chewing is associated with faster recovery of bowel function following cesarean section. It is safe, practical, inexpensive, and well tolerated. [ABSTRACT FROM AUTHOR]

Purpose: Use of thoracic epidural analgesia (TEA) with local anesthetic and adjuncts, such as opioids, are cornerstones of ERAS (Enhanced Recovery After Surgery) and are considered to play a key role in recovery after colorectal surgery. However, its effect on bowel function may lead to prolong hospital stay and is still a matter of debate. The purpose of this systemic review was to assess whether epidural analgesia could have a detrimental effect on bowel function in laparoscopic colorectal surgery with a subsequent effect on hospital stay duration, leading to failure of ERAS in colorectal surgery. Methods: A systematic review of randomized, controlled trials for the effect of epidural analgesia on laparoscopic colorectal surgery was performed. The effect on postoperative recovery was evaluated in terms of return of bowel function as the primary outcome, whereas length of stay (LOS), pain score on visual analogue scale, operative time, and incidence of postoperative complications and side-effects of analgesia were recorded as secondary outcomes. Results: Six trials published between 1999 and 2011 were included in the final analysis. TEA significantly improves return of bowel function assessed by time to first bowel motion [WMD −0.62 (−1.11, −0.12) with Z = 2.43; P = 0.02, 95 % confidence interval (CI)], and pain scores [WMD −1.23 (−2.4, −0.07)] with Z = 2.07; P = 0.04, 95 % CI]. TEA did not influence duration of hospital stay [WMD −0.47 (−1.55, 0.61)] with Z = 0.85 ( P = 0.39, 95 % CI). No significant increase in operative time or side effects was associated with TEA. Conclusions: Despite of some beneficial effect of epidural analgesia on return of bowel function and pain in laparoscopic surgery, it does not affect LOS, which is multifactorial. [ABSTRACT FROM AUTHOR]

The stomach acts as a barrier to ingested microbes, thereby influencing the microbial ecology of the entire gastrointestinal (GI) tract. The stomach microbiota and the role of human host and environmental factors, such as health status or medications, in shaping its composition remain largely unknown. We sought to characterize the bacterial and fungal microbiota in the stomach fluid in order to gain insights into the role of the stomach in GI homeostasis. Gastric fluid was collected from 25 patients undergoing clinically indicated upper endoscopy. DNA isolates were used for PCR amplification of bacterial 16S ribosomal RNA (rRNA) genes and fungal internal transcribed spacers (ITS). RNA isolates were used for 16S rRNA cDNA generation and subsequent PCR amplification. While all stomach fluid samples are dominated by the phyla Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Fusobacteria (>99% of sequence reads), the transcriptionally active microbiota shows significant reduction in Actinobacteria (34%) and increase in Campylobacter (444%) (P<0.003), specifically the oral commensal and suspected intestinal pathogen Campylobacter concisus. Bacterial but not fungal diversity is reduced by antibiotic treatment (28%; P<0.02), immunosuppression in transplant recipients and HIV/AIDS patients (42%; P<0.001) and gastric fluid pH >4 (70%; P<0.05). Immunosuppression correlates with decreased abundance of Prevotella (24%), Fusobacterium (2%) and Leptotrichia (6%) and increased abundance of Lactobacillus (3844%) (P<0.003). We have generated the first in-depth characterization of the human gastric fluid microbiota, using bacterial 16S rRNA gene and transcript, and fungal ITS amplicon sequencing and provide evidence for a significant impact of the host immune status on its composition with likely consequences for human health. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the time-profile of intragastric fluid volume in humans after intragastric administration of drug solution. Methods: Eight healthy volunteers were intragastrically administered 150 mL of drug solution containing atenolol (non-absorbable marker) and salicylic acid, then, aliquots of gastric fluid (ca. 2 mL) were sampled for 2 h through the catheter. Rate constants for secretion and emptying of the fluid were obtained by fitting the time-course of atenolol concentration to the simple gastric fluid transit model. Absorption of salicylic acid from the stomach was estimated by comparing its gastric concentration with that of atenolol. Results: Kinetic analysis of atenolol concentration in the stomach indicated a rapid emptying of the fluid with an average half-life of 4.2 min. Steady-state intragastric fluid volume in 8 volunteers was estimated as 4-133 mL with an average of 42 mL. Intragastric concentration (normalized by dose) of salicylic acid was always lower than that of atenolol, showing approximately 40% of salicylic acid was absorbed from the stomach before emptying to the intestine. Conclusions: This study provided valuable information on intragastric fluid dynamics and gastric drug absorption in humans to establish a better in vitro-in vivo correlation in oral drug absorption. [ABSTRACT FROM AUTHOR]

Background: Motilin, an endogenous gastrointestinal (GI) hormone, increases upper gastrointestinal tract motility and is associated with phase III of the gastric migrating motor complex. The motilin receptor agonist, atilmotin, at doses of 6, 30 or 60 microg intravenously (IV), increases the early phase of gastric emptying. Prior studies at higher doses of 100-450 microg IV demonstrated that some subjects developed noncardiac chest pain.Aims: The aim of this study is to determine the effects of atilmotin on esophageal, lower esophageal sphincter (LES), and gastric contractility and the development of esophageal-related symptoms.Methods: Ten healthy volunteers underwent esophageal manometry to study the effects of atilmotin on upper GI motility. Five subjects were studied on three separate days following administration of saline placebo and subsequent IV bolus dose of atilmotin (6, 30 or 150 microg). Another five subjects were studied at the highest dose (150 microg).Results: Atilmotin at 150 microg increased proximal gastric pressure by 6.5 mmHg (P = 0.001 compared with placebo). Atilmotin increased LES pressure at all studied doses; LES pressure increased from 24 +/- 2 mmHg following placebo injection to 34 +/- 4 mmHg following a 30 microg dose of atilmotin (P = 0.007). In the esophagus, atilmotin increased the percentage of failed swallows at the highest dose studied. Failed swallows increased from 17 +/- 7% following placebo injection to 36 +/- 7% following a 150 microg dose of atilmotin (P = 0.016). Atilmotin decreased distal esophageal contractile amplitude only at the highest dose studied, from 69 +/- 8 mmHg (placebo) to 50 +/- 5 mmHg following 150 microg atilmotin (P = 0.018). There were no serious adverse effects or episodes of chest pain with atilmotin.Conclusions: Atilmotin affects esophageal, LES, and gastric motility. LES and gastric pressures were increased, whereas there was disruption of esophageal peristalsis characterized by lower amplitude and failed contractions. [ABSTRACT FROM AUTHOR]

The formation and adaptation of gastric secretion was studied in the sports ontogeny of various wrestlers and of athletes retired from sport. Gastric secretion proved to depend strongly on the level of the wrestlers’ motor activity, which determined changes in the reactivity of the digestive apparatus and intensity of proteolysis (hypo- and hyperfunctions). Changes in the secretory gastric activity of wrestlers depended on their age and the duration and intensity of their physical exercises and were correlated with the body weight of the athletes. [ABSTRACT FROM AUTHOR]

The muscularis propria of the stomach is histologically divided into three layers; namely, the innermost oblique, the inner circular, and the outer longitudinal layers. In patients with gastric cancer the depth of tumor invasion has been reported to correlate with lymph node metastasis and prognosis. However, it is unclear whether the depth of tumor invasion in the muscularis propria has an effect on lymph node metastasis and prognosis. Fifty-nine gastric cancer patients with muscularis propria invasion were analyzed retrospectively. These patients were divided into two groups, the inner group, with invasion up to the inner circular layer; and the outer group, with invasion beyond the inner circular layer. The relationships between tumor invasion and clinicopathological factors and survival were evaluated. Of the 59 patients, 34 were classified as the inner group, and 25 were classified as the outer group. The inner group had a significantly lower probability of lymph node metastasis ( P = 0.0053) and a significantly better overall cancer-specific survival ( P = 0.017) than the outer group. Gastric cancers with muscularis propria invasion had heterogeneous prognoses according to the tumor depth in the muscularis propria layers. [ABSTRACT FROM AUTHOR]

Abstract  We studied the effects of immobilization and pain stress on motor and secretory function of the stomach in dogs and correction of these changes with bioactive supplement Lymphosan. The stress factors induced pronounced changes in physiological parameters: immobilization stress induced hypersecretion, while pain stress inhibited the glandular apparatus. In animals treated with Lymphosan, both stress factors produced less pronounced changes and motor and secretory functions of the stomach were near to the control level. Thus, when used as a corrector of stress reactions, Lymphosan produced adaptogenic effects on the stomach and normalized the stress-induced disturbances. [ABSTRACT FROM AUTHOR]

The propagation of the gastric slow wave is one of the most important spatial characteristics of gastric electrical activity (GEA). The time delay estimation (TDE) is an effective approach to quantitatively assessing the propagation velocity of GEA. Traditional TDE analyses are developed under the condition reported that the background noise in GEA analysis is Gaussian distributed. Due to the effects of spikes and/or motion artifacts, the GEA obtained from gastric serosal electrodes often contains sharp transitions. This paper proposes robust time delay estimation based on least mean p-norm blind channel identification (BCILMP) under alpha-stable noise condition. Compared with the least mean square time delay estimation (LMSTDE), the BCILMP provides better performance in the impulsive noise environments. The robustness of the proposed method is demonstrated through computer simulations in both Gaussian and alpha-stable noise environments. The results of the propagation velocity of real data obtained from gastric serosal electrodes in gastroparetic patients show that the propagation velocity in gastroparetic patients is slower than in the normal subjects reported in the literature, and the slow-wave propagation is directed proximally to distally from the corpus toward the pylorus but not all the variability of the propagation velocity increases monotonously. [ABSTRACT FROM AUTHOR]

Recently, tissue engineering of the autologous esophagus has been thought to provide a promising strategy for esophageal substitution. In this study, gastric acellular matrix (GAM) was used as a scaffold for regeneration of the esophagus in a rat model. Usage of GAM has an advantage that naturally derived extracellular matrix autograft can be prepared less invasively in a clinical setting. Twenty-seven F344 female rats were used as recipients. Patch defects created in the abdominal esophagus were replaced by GAM patch grafts. The rats were sacrificed 1 week to 18 months after implantation. The specimen was examined macroscopically as well as microscopically. 5'-Bromo-2'-deoxyuridine (BrdU) proliferation assay was performed in six rats that were sacrificed 1, 2, and 4 weeks after implantation. Twenty-four rats survived without complications. The graft site did not show esophageal stenosis or dilatation in any rat. Keratinized stratified squamous esophageal mucosa was regenerated in the entire graft 2 weeks after implantation. Regeneration of the muscle layer or lamina muscularis mucosae in the graft site was not observed even 18 months after implantation. Marked incorporation of BrdU was observed only in the mucosal layer but not in the muscle layer. GAM patch graft provided satisfactory mucosal regeneration of the esophagus without stenosis or dilatation, although muscle regeneration was still a future challenge. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) plays an important role as a nonadrenergic, noncholinergic inhibitory neurotransmitter in the GI tract. Our study aims were to investigate the effect of a single intragastric L-arginine (L-Arg) administration, as a source of NO, on proximal stomach tone in basal and postintragastric administration of a polymeric diet in humans and to evaluate concomitantly the effect on antral area as an indirect assessment of gastric emptying. Eight healthy volunteers were studied in a randomized double-blind crossover study after, respectively, 15 g L-Arg, 30 g L-Arg, or placebo administered in the stomach through a gastric tube. The drug administration was followed by a polymeric diet infusion (500 ml/500 kcal) at a rate of 250 ml/hr. Gastric tone variations were recorded with an electronic barostat, gastric emptying was concomitantly estimated by repeated ultrasound measurements of antral area, and symptoms were recorded throughout the experiment.L-Arg administration was associated with significantly higher increases in barostat bag volumes at both dosages, 30 g (117+/-16 ml) and 15 g (67+/-15 ml), compared to placebo (46+/-11 ml; P < 0.05). In response to the polymeric diet the 30-g L-Arg challenge was associated with a smaller increase in intrabag volume, whereas postinfusion final volumes did not differ in the three treatment conditions. Antral areas were not different at any time of measurement among the three challenges. Bloating and diarrhea were observed after 30-g L-Arg administration in five subjects of eight. Short-term L-Arg administration was able to induce proximal stomach relaxation that allowed a secondary response to enteral feeding only at the 15-g dosage. This 15-g dosage was as well tolerated as the placebo and was associated with no significant changes in gastric emptying patterns. [ABSTRACT FROM AUTHOR]

In the past, the omentum was considered to be an inert tissue without much biological significance. But since the beginning of the last century, innumerable studies and trials have been conducted by surgeons and scientists all over the world, which have proven that the omentum is a unique, physiologically dynamic tissue with immense therapeutic potential. We have undertaken the present review to provide a concise account of the variety of applications of the omentum in the various disciplines of surgical practice. An extensive search was carried out on the internet for indexed publications in the English literature using the keywords ‘omentum, omentoplasty and surgical uses of omentum.’ The search revealed about 86 publications. All those publications were systematically reviewed and analyzed. The inferences derived from those publications are methodically summarized. The omentum is indeed an organ of exceptional versatility. This review presented by us will enable the readers to appreciate the fact that, clearly the omentum was placed in the abdomen for a reason. [ABSTRACT FROM AUTHOR]

Myoelectric recordings from the intestines in conscious animals have been limited to a few electrode sites with relatively large inter-electrode distances. The aim of this project was to increase the number of recording sites to allow high-resolution reconstruction of the propagation of myoelectrical signals. Sets of six unipolar electrodes, positioned in a 3x2 array, were constructed. A silver ring close to each set served as the reference electrodes. Inter-electrode distances varied from 4 to 8 mm. Electrode sets, to a maximum of 4, were implanted in various configurations allowing recording from 24 sites simultaneously. Four sets of 6 electrodes each were implanted successfully in 11 female Beagles. Implantation sites evaluated were the upper small intestine (n=10), the lower small intestine (n=4) and the stomach (n=3). The implants remained functional for 7.2 months (median; range 1.4-27.3 months). Recorded signals showed slow waves at regular intervals and spike potentials. In addition, when the sets were positioned close together, it was possible to re-construct the propagation of individual slow waves, to determine their direction of propagation and to calculate their propagation velocity. No signs or symptoms of interference with normal GI-function were observed in the tested animals. With this approach, it is possible to implant 24 extracellular electrodes on the serosal surface of the intestines without interfering with its normal physiology. This approach makes it possible to study the electrical activities of the GI system at high resolution in vivo in the conscious animal. [ABSTRACT FROM AUTHOR]

Background: The low-pressure airway seal of the Classic laryngeal mask airway (CLMA) can be inadequate for positive pressure ventilation (PPV) in children. The ProSeal laryngeal mask airway (PLMA) forms a more effective seal of the airway than the CLMA and facilitates gastric tube placement in adults. The size 3 PLMA can be used in adults and children.Methods: The CLMA and PLMA were studied in random order -- crossover -- in 30 anaesthetized, non-paralysed children (average age 10.6 years, average body weight 39 kg). Airway leak pressure, maximum tidal volume, ease of insertion, quality of initial airway and fiberoptic position were determined. Gastric tube placement was assessed for the PLMA.Results: The mean airway leak pressure in neutral head position (27.0 vs. 16.8 cm H(2)O), maximum flexion (38.3 vs. 26.2 cm H(2)O) and maximum extension (21.1 vs. 14.2 cm H(2)O) as well as the mean maximum tidal volume (1432 vs. 1062 ml) were significantly higher (p<0.001) for the PLMA. Air insufflation into the stomach occurred with the CLMA but not with the PLMA. Gastric tube placement was possible in all patients.Conclusions: The high reliability of g-tube placement and the significantly increased airway leak pressure seem to make the size 3 PLMA a more suitable device for PPV in children than the same size CLMA. [ABSTRACT FROM AUTHOR]

Rectal distension affects upper GI myoelectrical activity and motility. The aim of this experiment was to investigate the effect of rectal distension on gastric tone, accommodation, and the underlying mechanism. Seven healthy dogs were surgically prepared and studied. Gastric tone and accommodation were assessed with a barostat. In Experiment 1, the effect of rectal distension on gastric tone and accommodation was evaluated; in Experiment 2, rectal distensions with various volumes were randomly applied and its effects on gastric tone were evaluated; and in Experiment 3, the role of the cholinergic pathway in distension-induced gastric relaxation was assessed. The results showed the following. (1) Rectal distension exerted an inhibitory effect on gastric tone, and this response was distension volume-dependent. (2) Postprandial gastric volume was similar in the control (468.6 +/- 24.7 ml) and the distension study (463.2 +/- 17.5 ml). However, rectal distension increased the preprandial gastric volume, and subsequently decreased the extent of gastric accommodation (139.3 +/- 34.7 ml), which was significantly lower than that of the control (383.2 +/- 26.3 ml; P < 0.001). (3) An intravenous bolus of atropine increased the astric volume from the baseline of 89.4 +/- 12.6 ml to 161.5 +/- 9.8 ml (P < 0.01), and subsequent rectal distension further increased this volume, but the overall change was comparable between the control (297.6 +/- 18.7 ml) and the atropine study (312.1 +/- 21.9 ml; P > 0.05). In conclusion, rectal distension inhibits gastric tone in a volume-dependent manner and impairs gastric accommodation. Atropine dose not block the effect of rectal distension on proximal gastric tone, suggesting that the observed effect may not be mediated by cholinergic pathway. [ABSTRACT FROM AUTHOR]

Although there are many studies evaluating the effect of elevated gastric pressure in total wrap and partial anterior and posterior wrap fundoplications, there are no ex vivo manometric studies evaluating the contribution of elevated gastric pressure to prevention of gastroesophageal reflux (GER) in Collis and uncut Collis procedures without fundoplication. An experimental study has been designed to determine the contribution of elevated intragastric pressure in the absence of in vivo anatomic and functional factors to the prevention of GER in Collis and uncut Collis without fundoplication procedures. The study was conducted on adult male New Zealand rabbits' esophagus and stomachs. The stomachs were divided into four groups: total wrap fundoplication group, partial wrap anterior fundoplication group, Collis without fundoplication group, and uncut Collis without fundoplication group. The minimum intragastric pressure (MIP) causing GER of each stomach before and after the procedure were measured with a two-way catheter introduced through the pylorus. The MIP values causing GER of the total wrap and partial anterior wrap fundoplication groups were found to be significantly higher compared with the basal intragastric pressures (P < 0.01). The MIP values causing GER of the Collis and uncut Collis without fundoplication groups were not significantly different compared with basal intragastric pressures (P > 0.05). The elevated gastric pressure is found to be insufficient to prevent GER in Collis and uncut Collis without fundoplication procedures. The efficacy of these procedures in preventing GER seems to be related to the anatomic and functional factors affecting in vivo circumstances. [ABSTRACT FROM AUTHOR]

This study investigated the effect of gastric electrical stimulation (GES) on vagal activity and its possible vagal afferent-mediated mechanisms. Sixty rats implanted with gastric serosal electrodes were divided into six groups (control, vehicle, local capsaicin, perivagal capsaicin, systemic capsaicin, and vagotomy). GES with six sets of parameters was performed in the control group; and GES with one set of effective parameters was performed in the other five groups. Spectral analysis of heart rate variability was used to assess vagal activity. Regular gastric slow waves were recorded in the control rats with a frequency of 4.8 cycles/min. Vagotomy significantly reduced the frequency of the gastric slow wave but did not induce dysrhythmia. Capsaicin did not alter the gastric slow wave. Short-pulse (300-microsec) GES significantly increased vagal activity at a frequency four times the intrinsic slow-wave frequency. Stimulation at a lower frequency or with a long pulse (300 msec) had no effect on vagal activity. Vagotomy or capsaicin administered perivagally, systemically, or locally abolished the effect of GES on the vagal activity. GES with short but not long pulses is capable of altering vagal activity. This effect is mediated by capsaicin-sensitive vagal afferent fibers. [ABSTRACT FROM AUTHOR]

Gastric electrical stimulation (GES) was shown to improve symptoms in patients with gastroparesis. However, the underlying mechanisms remain unclear. This study assessed the influence of various patterns of GES on fasting and postprandial gastric acid secretion and 24-hr gastric pH. Eight healthy dogs were studied and we found that in the fasting state, low-frequency, long-pulse (6/12-cpm, 375-msec, 4-mA) GES at the proximal stomach significantly inhibited the secretion of gastric juice (P < 0.05). No such effect was observed during GES (6/12 cpm) at the distal stomach. In the postprandial period, low-frequency, long-pulse GES at both proximal and distal sites and at both frequencies did not significantly affect gastric acid secretion. High-frequency, short-pulse GES, investigated for obesity (21 Hz, 8 mA, and 250 microsec, with 2 secs on, 3 sec off), at the proximal and distal stomach did not significantly affect the 24-hr gastric pH profile. In conclusion, GES with various stimulation parameters, and at various sites, has little effect on gastric acid secretion. The clinical effects induced by GES at these parameters may not be related to their effect on gastric acid homeostasis. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the characteristics and orientation of gastric dysrhythmia using multichannel serosal recordings in dogs. Ten dogs chronically implanted with four to eight pairs of electrodes were studied. Gastric slow waves were recorded in four sessions: postsurgical and after atropine, vasopressin, and glucagon. A total of 554.7 min of bradygastria, 201 min of tachygastria and 22.3 min of arrhythmia were observed in the recordings. The majority of bradygastria (80.5 +/- 9.4%) originated in the proximal stomach (P < 0.04, vs other locations) and propagated all the way to the distal antrum. In contrast, tachygastria mainly originated in the distal antrum (80.6 +/- 8.8%) (P < 0.04, vs other locations) and propagated partially or all the way to the proximal stomach. Dysrhythmia appeared intermittently with normal gastric slow waves. In all recordings, normal slow waves were present 38.0 +/- 5.3% of the time, while bradygastria, tachygastria, and arrhythmia were present 35.9 +/- 5.3%, 23.0 +/- 1.6%, and 2.4 +/- 0.5% of the time, respectively. The prevalence of dysrhythmia was highest in the distal antrum (80.4%) (P < 0.01) and lowest in the proximal part of the stomach. In conclusion, tachygastria originates from an ectopic pacemaker in the distal antrum. It may completely or partially override the normal slow waves. Bradygastria is attributed to a decrease in the frequency of the normal pacemaker in the corpus. The prevalence of gastric dysrhythmia is different in different locations of the stomach and is highest in the distal antrum. [ABSTRACT FROM AUTHOR]

The gastrocolonic response consists of a prompt increase in colonic tone after a meal. With a barostat and a high compliant air-filled bag, it is possible to measure rectal tone by recording changes in volume at a constant intrabag pressure. The aim of this study was to evaluate the gastrorectal response in males and females as well as the effect of different caloric loads on the gastrorectal response. In 33 volunteers a barostat procedure during basal conditions and after a 600-kcal meal was performed. In 26 volunteers the procedure was repeated with a 1000-kcal meal. A meal response was defined as a decrease in volume of more than 10%. Phasic volume events (PVE) were defined as a 10% decrease in volume of 15-60 sec duration. After a 600-kcal meal, the decrease in volume after 1 hr was 28 +/- 7% (mean +/- SEM, P < 0.001). A meal response was found in 64% of the subjects. Parous females had a diminished meal response compared with nulliparous females (2 +/- 5% and 48 +/- 11%, P < 0.001). After the 600-kcal meal, PVEs increased from 3 to 10/hr (P = 0.001). In the 26 subjects, volume decrease was 40 +/- 9% after the 1000-kcal meal and 20 +/- 7% after the 600-kcal meal (P = 0.28). In the high-calorie meal, 18 subjects (69%) had a response versus 14 (54%) in the low-calorie meal (NS). Enhancing the caloric load of the meal did not increase the amounts of PVEs. In conclusion, a gastrorectal response occurs in 64% of the healthy subjects after a 600-kcal meal. The gastrorectal response can be measured to a similar extent in men and nulliparous women; however, the response is significantly impaired in parous women. This is possibly due to neurogenic damage during childbirth. Increasing the caloric load did not increase the gastrorectal response. Therefore, to study gastrorectal meal response with the barostat, a meal of 600-kcal is sufficient and a correction for parity should be made when results are compared. [ABSTRACT FROM AUTHOR]

Although the dominant frequency at 3 cpm of electrogastrography (EGG) is reported to shift to a higher frequency during motion sickness (MS), it is unclear whether the normal slow wave (NSW) disappears or not. The authors investigated changes in NSW using vector analysis of EGG. Fourteen subjects were exposed to a Coriolis stimulation to evoke MS. EGG was recorded from two sets of bipolar leads, placed perpendicular to each other representing x and y axes. Trajectories for each frequency were drawn on the x-y plane. The amplitude and phase difference at NSW were compared before, during, and after the stimulus for each subject. In those with a change in phase difference, changes in NSW and tachygastria were negatively correlated (P = -0.048), whereas in those without a change, they were not correlated. This indicated two different kinds of tachygastria due to MS: tachygastria with and without a change in NSW. [ABSTRACT FROM AUTHOR]

Our aim was to investigate the effect of motilin on postprandial proximal gastric motor and sensory function in healthy volunteers. Ten fasted, healthy volunteers were infused intravenously with synthetic motilin or placebo over 90 min. A liquid meal (200 ml) was ingested within 2 min at the start of the infusion. Proximal gastric volume was measured with a barostat device. Abdominal symptoms were scored by visual analog scales. Plasma motilin concentrations were measured using RIA. Endogenous motilin levels were not affected by meal ingestion. After meal intake, gastric relaxation was similar for motilin and placebo. After postprandial relaxation, motilin resulted in a faster return of gastric volume to baseline (P = 0.007). Motilin significantly increased postprandial feelings of nausea (P = 0.03) and tended to increase abdominal pain and abdominal tension. In conclusion, after normal postprandial gastric relaxation, motilin accelerated the return of gastric volume to baseline. In addition, motilin increased postprandial feelings of nausea. [ABSTRACT FROM AUTHOR]

Patients after bone marrow or stem cell transplant often develop gastrointestinal symptoms. The aim of this study was to investigate possible impairment of gastric myoelectrical activity in these patients. The study was performed in 15 patients who had had bone marrow or stem cell transplant and 13 healthy subjects. Gastric myoelectrical activity was assessed using electrogastrography. The electrogastrogram (EGG) was made for 30 min in the fasting state and 60 min after a test meal (475 kcal; turkey sandwich). Overall and minute-by-minute spectral analyses were performed to derive various parameters of the EGG. Compared with the healthy controls, the patients showed a significantly higher percentage of arrhythmia (no obvious rhythmicity observed in the EGG) in both fasting (17.6 +/- 3.8% vs 7.1 +/- 2.17%, P < 0.02) and fed (11.4 +/- 2.65% vs 4.19 +/- 1.04%, P < 0.02) state. The patients showed a significantly higher instability coefficient of the dominant frequency in the fasting state than in the controls (0.51 +/- 0.06 vs 0.29 +/- 0.18, P < 0.008). The total average symptom score was 3.93 +/- 0.84 in the patients and 0 in the controls, and a relatively weak but significant correlation was found between the symptom scores and the percentage of arrhythmia in the patients in fed state (r = 0.69, P < 0.02). It was concluded that patients with bone marrow or stem cell transplant have excessive arrhythmia that is correlated with their dyspeptic symptoms. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to examine postprandial myoelectric activity of the stomach and gastric activity associated with space motion sickness using electrogastrography. Three crewmembers participated in this investigation. Preflight, subjects exhibited normal postprandial responses to the ingestion of a meal. Inflight, crewmembers exhibited an abnormal decrease in the power of the normal gastric slow wave after eating on flight day 1, but had a normal postprandial response by flight day 3. Prior to and during episodes of nausea and vomiting, the electrical activity of the stomach became dysrhythmic with 60-80% of the spectral power in the bradygastric and tachygastric frequency ranges. These findings indicate that gastric motility may be decreased during the first few days of space flight. In addition, changes in the frequency of the gastric slow wave associated with space motion sickness symptoms are consistent with those reported for laboratory-induced motion sickness. [ABSTRACT FROM AUTHOR]

Glutamate is an important excitatory amino acid and plays a major role in brain stem neurotransmission. Although the effect of glutamate on esophageal motility is well studied, its role in the triggering of transient lower esophageal sphincter relaxations (TLESRs) remains to be determined. Esophageal manometry was performed in 10 healthy volunteers using a perfused sleeve assembly. The effect of intragastric instillation of the nonspecific N-methyl-D-aspartate receptor antagonist dextromethorphan (30 mg) and the glutamate-release inhibitor riluzole (100 mg) was evaluated on esophageal motility and on the rate of TLESRs during isovolumetric gastric distension (500 ml). Dextromethorphan and riluzole had no effect on the amplitude or peristaltic velocity of esophageal pressure waves, basal LES pressure, or LES relaxation after water swallowing. Gastric distension increased the rate of TLESRs from 2.0 (1.0-3.5)/45 min to 5.0 (4.0-7.0)/45 min during placebo (P < 0.05). In contrast, the rate of TLESRs during gastric distension was significantly reduced with riluzole [4.0 (2.5-6.0)/45 min], but not with dextromethorphan. In conclusion, riluzole had no effect on swallow-induced LES relaxation, esophageal peristalsis, or gastric tone, but it reduced the number of TLESRs evoked by gastric distension. These findings suggest that glutamate may be involved in the neurocircuitry underlying TLESRs. However, as the effect was only marginal, additional studies are required to confirm our observations. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the correlation of gastric emptying with gastric myoelectrical activity recorded from internal serosal electrodes and with gastric motility measured from strain gauges. The study was performed in eight healthy dogs chronically implanted with four pairs of electrodes and two strain gauges on the gastric serosa and equipped with a duodenal fistula for the assessment of gastric emptying. Each dog was fed four liquid test meals on four separate days with identical calories (320 kcal) and volume (473 ml). A correlation was found between gastric emptying and the energy of contraction in the frequency band of 3.75-7.50 cycles/min during the first 30 min after the meal (r = 0.46, P < 0.05). While none of the parameters of gastric myoelectrical activity was correlated with gastric emptying, two major parameters, percentage of regular gastric slow waves and percentage of slow-wave coupling, were found to be associated with delayed gastric emptying. A significant correlation was found between the frequency of gastric slow waves and that of the contractions in both fasting (r = 0.83, P < 0.001) and fed state (r = 0.70, P < 0.001 at 30 min, r = 0.86, P < 0.001 at 60 min). It was concluded that gastric emptying is correlated with the strength of gastric contractions in a frequency range identical to that of the gastric slow waves, and there is no one-to-one correlation between gastric emptying of liquids and any parameters of gastric myoelectrical activity. However, major parameters of gastric myoelectrical activity are associated with gastric emptying. [ABSTRACT FROM AUTHOR]

Electrogastrography (EGG) is the transcutaneous measurement of gastric electrical activity. The aims of this study were to validate the electrode placement position in neonatal electrogastrography using ultrasonography to localise the stomach, and to describe the observed EGG frequency characteristics. Fifteen neonates with no known abdominal disorder were studied. Two bipolar EGG recordings were obtained from each subject, the first from electrodes placed at sites localized by ultrasound and the second from electrodes placed at the currently recommended sites. Paired sample t tests were used to compare electrode positioning and electrogastrographic data. There were 15 subjects with a mean age of 36 days (range 1–95). While there was a significant difference in the position of electrodes at each site, the EGG recordings did not differ. The 3-cycle/minute (2.6–3.7cpm) activity ranged from 30% to 84% of recorded time (mean at sites localized with ultrasound was 53%, and at currently recommended sites it was 50%; difference not significant, P = 0.155). Bradygastria (<2.6 cpm) was observed in the range of 2–29% of recorded time (mean at sites localised with ultrasound was 12.9%, and at currently recommended sites it was 11.7%; difference not significant, P = 0.40). Tachygastria (3.2–10 cpm) was shown to be in the range of 10–58% of recorded time (mean at sites localized with ultrasound was 33.3%, and at currently recommended sites it was 38.7%; difference not significant; P = 0.044). In conclusion, there was no significant difference between EGG recordings taken from electrode sites localized by ultrasound and those recommended by manufacturers of the electrogastrogram, thus confirming the validity of the manufacturer's recommended electrode positioning. The pattern of electrical control activity in the normal neonatal stomach appears to be different from that demonstrated in adults. Bradygastria and tachygastria are seen more frequently, with fewer periods of 3 cpm activity. [ABSTRACT FROM AUTHOR]

The Magenstrasse and Mill (M&M) procedure for obesity is designed to preserve normal gastric emptying mechanisms. The hypothesis investigated in this study was that gastric emptying would be normal after the M&M gastroplasty. Gastric emptying studies were performed using both liquid and solid test meals, in ten morbidly obese patients (MO group) and in 13 patients after the M&M procedure (MM group). Seven people of normal weight served as controls and were matched for age, sex and height to the M&M and MO groups. Three years after the M&M procedure, mean (SD) weight loss was 42 (19) kg, with a mean loss of excess weight of 58% (20%). Gastric emptying half-times (t[sub 1/2] ) are expressed in minutes, as median values (25th and 75th percentiles). The t[sub 1/2] for solids was 97 (85–110) min in the control group, 140 (86–220) min in the MO group and 79 (46–150) min in the MM group. Median gastric emptying for solids was 0.7% (0.6%–0.8%) per minute in the control group, 0.5% (0.3%–0.8%) in the MO group and 0.9% (0.4%–1.4%) in the M&M group. There were no statistically significant differences in the emptying times of the three groups. It is concluded that the M&M procedure achieves acceptable weight loss, while preserving gastric emptying mechanisms and thus minimising possible side-effects such as vomiting, dumping and diarrhoea, which are common complications of gastric bypass procedures. [ABSTRACT FROM AUTHOR]

Some people attribute dyspeptic symptoms to drinking coffee, suggesting that coffee affects one or more functions of the proximal gastrointestinal tract. In a randomized controlled, cross-over, single-blinded study, the effects of coffee on gastric relaxation, gastric wall compliance and sensations, elicited by distension, were investigated in 10 healthy volunteers. Using the barostat technique, volume changes of an intragastric bag were recorded for 20 min after intragastric administration of 280 ml of coffee or water. Then, after deflation, the volume of the bag was increased stepwise every 3 min to assess gastric wall compliance and wall tension. At the end of every volume step, sensations (nausea, pain, and bloating) were scored. During the first 20 min after coffee administration, the volume change of the intragastric bag was larger than after water (P < 0.05). There were no differences in gastric wall compliance, wall tension, or symptom scores. In conclusions, coffee, in comparison with water, enhances the adaptive relaxation of the proximal stomach, but has no effect on its wall compliance, wall tension, or sensory function. [ABSTRACT FROM AUTHOR]

We investigated the possible involvement of the upper alimentary tract in vincristine (VCR)-induced dysmotility. Gastric contractions were recorded by a strain-gauge force transducer in conscious rats. Rats were injected with various doses of VCR followed by continuous recording for 12 hr. Additionally, 3-hr recordings to study the later effects were performed one and three days after injection. Gastric motility was dose-dependently increased by VCR. Post- versus preinjection motility index (MI; area under contraction waves) ratios were 0.78+/-0.12 for saline and 1.95+/-0.21 for VCR at 0.75 mg/kg. This increase in MI was completely inhibited by atropine and hexamethonium. MI one day after injection of VCR (0.75 mg/kg) was significantly less than in control (0.32+/-0.10 vs 0.92+/-0.24, respectively). The decrease was reversed by acetylcholine. In conclusion, VCR first increased gastric motility, and this was followed by a gradual decrease in conscious rats. These alterations may involve a presynaptic cholinergic pathway. [ABSTRACT FROM AUTHOR]

This study investigated the impact of gastric electrical uncoupling on the dynamics of the level of deterministic chaos in cutaneous gastric electrical signals. Eight-channel electrogastrograms (EGG) were recorded from 16 unconscious dogs. Controlled gastric electrical uncoupling was introduced by circumferentially cutting the whole gastric muscle at two different locations. Three separate 30-min EGG recordings were obtained from each dog in the three different states (basal, after the first cut, and after the second cut). The Lyapunov exponents were calculated from sixteen 6.31-min intervals with 75% overlap obtained from each channel in each state. Inadequate EGG signals from which the Lyapunov exponent could not be reliably calculated were quantitatively discarded. The variance and the standard deviation of the three Lyapunov exponent distributions obtained from each channel were studied, and the mean values were subjected to a Student t-test. In 65.6% of all studied channels, the level of chaos was significantly different (p< 0.01) after the first cut compared to the basal state, but no predominant direction of variation was observed (47. 7% increment vs. 52.5% decrement). After the second cut, 63.6% of the channels studied showed significantly greater Lyapunov exponent compared to the basal state, and 63.1% exhibited significantly greater (p< 0.01) level of chaos compared to the intercut state. The dynamics of the level of deterministic chaos in canine electrogastrograms is highly sensitive to severe gastric electrical uncoupling. Moreover, some channel configurations seem to be more sensitive than others in detecting uncoupling. [ABSTRACT FROM AUTHOR]