Pig Stomach Research Articles

Mucoadhesive properties of sulphated polysaccharides carrageenans from red seaweed families Gigartinaceae and Tichocarpaceae

The mucoadhesive properties of different types of carrageenan (kappa-, kappa/beta-, iota/kappa- and lambda-CRGs) isolated from red seaweed families Gigartinaceae and Tichocarpaceae collected on the Pacific coast were studied. We examined the interaction between CRGs and pig stomach mucin in dilute aqueous solutions using a set of methods. Measurements of the dynamic light scattering of mucin in the presence of CRG showed that the polysaccharides cause aggregation of mucin particles, as confirmed by microscopy data. The addition of CRGs to solutions of mucin resulted in the formation of a mixture that changed the charge of mucin, especially in the case of kappa- and kappa/beta-CRGs. The interaction between CRG and porcine gastric mucin in the presence of various additives confirmed that hydrogen bonds and electrostatic interactions are complemented when CRG and mucin are mixed in an aqueous medium, which is also confirmed by in vitro methods based on measurements of work of adhesion and shear stress. Kappa- and kappa/beta-CRGs that contain 3,6-anhydro-α-d-galactopyranose chains (DA) have high molecular weight and exhibit a high density of available hydrogen bonding groups able to interact more strongly with mucin glycoproteins.

Morphological and molecular characteristics of adult worms of Gnathostoma Owen, 1836 (Nematoda) collected from domestic pigs in Dien Bien Province, northern Vietnam

Gnathostomes are of interest because of their unique appearance and medical importance. Among 13 valid species of the genus Gnathostoma Owen, 1836 (Nematoda: Spirurida), two species, G. doloresi Tubangui, 1925 and G. hispidum Fedtschenko, 1872, are parasites of pigs but their larvae can infect humans to cause gnathostomiasis. In this study, we collected adults of Gnathostoma sp. from the stomach of domestic pigs (Sus scrofa domesticus Linnaeus) from Dien Bien Province, northern Vietnam. Morphologically, nematodes found here are most similar to G. doloresi with a slight difference in the spicules of males. In contrast, they are genetically distinct from G. doloresi and other species of Gnathostoma in both ITS2 and cox1 sequences. The findings of the present study suggest that specimens of Gnathostoma sp. found in Dien Bien are likely a new species and emphasise the need of further studies on the taxonomy and phylogenetic relationship of species of Gnathostoma. Special attention should also be paid to swine and human gnathostomiasis in Dien Bien Province, Vietnam and the neighbouring areas of China and Laos.

Distribution and co-expression patterns of specific cell markers of enteroendocrine cells in pig gastric epithelium

Although the pig is an accepted model species for human digestive physiology, no previous study of the pig gastric mucosa and gastric enteroendocrine cells has investigated the parallels between pig and human. In this study, we have investigated markers for each of the classes of gastric endocrine cells, gastrin, ghrelin, somatostatin, 5-hydroxytryptamine, histidine decarboxylase, and PYY cells in pig stomach. The lining of the proximal stomach consisted of a collar of stratified squamous epithelium surrounded by gastric cardiac glands in the fundus. This differs considerably from human that has only a narrow band of cardiac glands at its entrance, surrounded by a fundic mucosa consisting of oxyntic glands. However, the linings of the corpus and antrum are similar in pig and human. Likewise, the endocrine cell types are similar and similarly distributed in the two species. As in human, gastrin cells were almost exclusively in the antrum, ghrelin cells were most abundant in the oxyntic mucosa and PYY cells were rare. In the pig, 70% of enterochromaffin-like (ECL) cells in the antrum and 95% in the fundus contained 5-hydroxytryptamine (5-HT), higher proportions than in human. Unlike the enteroendocrine of the small intestine, most gastric enteroendocrine cells (EEC) did not contain colocalised hormones. This is similar to human and other species. We conclude that the pig stomach has substantial similarity to human, except that the pig has a protective lining at its entrance that may reflect the difference between a pig diet with hard abrasive components and the soft foods consumed by humans.

Feasibility of High-Resolution Electrical Mapping for Characterizing Conduction Blocks Created by Gastric Ablation.

The interstitial cells of Cajal (ICC) initiate, coordinate and propagate bioelectrical slow wave activity that drives gastric motility. In the healthy human stomach, slow wave activity is highly organized. Gastric motility disorders are associated with dysrhythmias. While ablation is widely used to treat cardiac dysrhythmias, this approach has yet to be trialed in the stomach. In this study, radiofrequency (RF) ablation was applied in pig stomachs in vivo to create targeted electrical conduction blocks. Ablations were performed at temperature control mode (55-70°C), and resultant conduction blocks were identified and verified using high-resolution electrical mapping. Termination of slow wave propagation at ablation sites was confirmed by a decrease in extracellular slow wave amplitude from 1.7 ± 0.2 mV to an undetectable amplitude, as well as spatiotemporal pattern analysis of conduction blocks. The use of high-resolution electrical mapping can now be employed to investigate ablation as a potential therapy for gastric dysrhythmias in motility disorders.

EndoClot®SIS Polysaccharide Injection as a Submucosal Fluid Cushion for Endoscopic Mucosal Therapies: Results of Ex Vivo and In Vivo Studies.

There are many studies on submucosal injection materials, but their clinical use is restricted for various reasons. The objective of this study was to compare the feasibility and safety of injected EndoClot®SIS polysaccharide as a submucosal injection material (SFC) in ESD in the pig stomach to that of injected sigMAVisc™ or Eleview™. Four pig stomachs were used for the ex vivo study. Eighteen pigs were used for the in vivo study. In the ex vivo study, four injections were made in the gastric submucosa to induce submucosal uplift and extend its duration. Tissue change was observed. The in vivo study was performed in 2 steps. First, 3 injections were made in the esophageal mucosa to induce submucosal uplift and extend its duration. Histological change was observed. Second, ESD was performed in the stomach by injecting EndoClot®SIS polysaccharide, sigMAVisc™, or Eleview™ (each, n = 6) as an SFC. The effects of these agents on wound healing were examined. We evaluated the efficacy and safety of endoscopic surgery after EndoClot®SIS polysaccharide injection. EndoClot®SIS polysaccharide produced a longer-lasting elevation with clearer margins than was achieved by sigMAVisc™, Eleview™, or 0.9% NaCl and thereby enabled precise ESD without complications, such as bleeding and perforation. No obvious histopathological damage was observed at the injection site on endoscopy and histology. Submucosally injected EndoClot®SIS polysaccharide increased the effective separation of the mucosa and submucosa and reduced surgical complications. Hence, EndoClot®SIS polysaccharide injection is a safe and effective submucosal injection material.

Chitosan composite microparticles: A promising gastroadhesive system for taxifolin

Taxifolin possesses gastroprotective property but is characterized by low water solubility, is instabile in alkaline medium, and is degraded by the intestinal bacteria flora. The purpose of the work was therefore to produce a gastroadhesive formulation to prolong taxifolin residence time and release in the stomach. We first demonstrated that taxifolin is stable in simulated gastric fluid with or without pepsin and mucus, and is able to cross pig gastric mucus layer and stomach mucosa. Next, gastromucoadhesive microparticles composed of Syloid® AL-1 mesoporous silica, chitosan and HPMC were produced using spray-drying. Microparticles were characterized by a spherical shape and a mean volume-equivalent diameter around 12 μm. The optimized microparticles were able to release taxifolin and to adhere to pig stomach mucosa for 5 h.

A Pilot Study of Endoscopic Submucosal Dissection Using an Endoscopic Assistive Robot in a Porcine Stomach Model.

Background/AimsEndoscopic assistive devices have been developed to reduce the complexity and improve the safety of surgeries involving the use of endoscopes. We developed an assistive robotic arm for endoscopic submucosal dissection (ESD) and evaluated its efficiency and safety in this in vitro pilot study.MethodsESD was performed using an auxiliary transluminal endoscopic robot. An in vitro test bed replicating the intra-abdominal environment and pig stomachs were used for the experiment. Participants were divided into skilled operators and unskilled operators. Each group performed ESD 10 times by using both conventional and robot-assisted methods. The perforation incidence, operation time, and resected mucous membrane size were measured.ResultsFor the conventional method, significant differences were noted between skilled and unskilled operators regarding operation time (11.3 minutes vs 26.7 minutes) and perforation incidence (0/10 vs 6/10). Unskilled operators showed a large decrease in the perforation incidence with the robot-assisted method (conventional method vs robot-assisted method, 6/10 vs 1/10). However, the operation time did not differ between the conventional and robot-assisted methods. On the other hand, skilled operators did not show differences in the operation time and perforation incidence between the conventional and robot-assisted methods. Among both skilled and unskilled operators, the operation time decreased with the robot-assisted method as the experiment proceeded.ConclusionsThe surgical safety of unskilled operators greatly improved with robotic assistance. Thus, our assistive robotic arm was beneficial for ESD. Our findings suggest that endoscopic assistive robots have positive effects on surgical safety.

Computational Models for the Mechanical Investigation of Stomach Tissues and Structure.

Bariatric surgery is performed on obese people aiming at reducing the capacity of the stomach and/or the absorbing capability of the gastrointestinal tract. A more reliable and effective approach to bariatric surgery may integrate different expertise, in the areas of surgery, physiology and biomechanics, availing of a strong cooperation between clinicians and engineers. This work aimed at developing a computational model of the stomach, as a computational tool for the physio-mechanical investigation of stomach functionality and the planning of bariatric procedures. In this sense, coupled experimental and numerical activities were developed. Experimental investigations on pig and piglet stomachs aimed at providing information about stomach geometrical configuration and structural behavior. The computational model was defined starting from the analysis of data from histo-morphometric investigations and mechanical tests. A fiber-reinforced visco-hyperelastic constitutive model was developed to interpret the mechanical response of stomach tissues; constitutive parameters were identified considering mechanical tests at both tissue and structure levels. Computational analyses were performed to investigate the pressure-volume behavior of the stomach. The developed model satisfactorily interpreted results from experimental activities, suggesting its reliability. Furthermore, the model was exploited to investigate stress and strain fields within gastric tissues, as the stimuli for mechanoreceptors that interact with the central nervous system leading to the feeling of satiety. In this respect, the developed computational model may be employed to evaluate the influence of bariatric intervention on the stimulation of mechanoreceptors, and the following meal induced satiety.

Development of a New Laparoscopic Detection System for Gastric Cancer Using Near-Infrared Light-Emitting Clips with Glass Phosphor.

Laparoscopic surgery is now a standard treatment for gastric cancer. Currently, the location of the gastric cancer is identified during laparoscopic surgery via the preoperative endoscopic injection of charcoal ink around the primary tumor; however, the wide spread of injected charcoal ink can make it difficult to accurately visualize the specific site of the tumor. To precisely identify the locations of gastric tumors, we developed a fluorescent detection system comprising clips with glass phosphor (Yb3+, Nd3+ doped to Bi2O3-B2O3-based glasses, size: 2 mm × 1 mm × 3 mm) fixed in the stomach and a laparoscopic fluorescent detection system for clip-derived near-infrared (NIR) light (976 nm). We conducted two ex vivo experiments to evaluate the performance of this fluorescent detection system in an extirpated pig stomach and a freshly resected human stomach and were able to successfully detect NIR fluorescence emitted from the clip in the stomach through the stomach wall by the irradiation of excitation light (λ: 808 nm). These results suggest that the proposed combined NIR light-emitting clip and laparoscopic fluorescent detection system could be very useful in clinical practice for accurately identifying the location of a primary gastric tumor during laparoscopic surgery.

Tumor localization using radio-frequency identification clip marker: experimental results of an ex vivo porcine model.

With the widespread use of minimally invasive surgery, tumor detection is becoming more difficult. We present the experimental results of a radio-frequency identification (RFID) lesion detection system in an ex vivo porcine model. The efficacy and feasibility of a newly developed RFID lesion detection system were examined. It was applied to the stomach and colon of pigs weighing 40kg. The RFID clip was attached to the upper and lower mucosal sides of the stomach. Colon specimens with thin and thick walls were used. The clipped sites were marked on the serosa by a pin. The longest distance from the pin the RFID tag could be detected was measured 25 times in each direction. In the upper gastric wall, the RFID tag detection distance was 4.5 ± 0.9mm, 5.6 ± 0.7mm, 12.5 ± 0.7mm, and 5.3 ± 0.5mm in the four directions, respectively (right, left, upper, and lower). In the antrum, the RFID tag detection distance was 5.8 ± 0.7mm, 6.9 ± 0.5mm, 5.6 ± 0.5mm, and 3.7 ± 0.5mm in the four directions. In the thin colon, the RFID tag detection distance was 6.3 ± 0.5mm, 5.0 ± 0.5mm, 9.7 ± 0.7mm, and 6.4 ± 0.4mm in the four directions. In the thick colon, the RFID tag detection distance was 3.5 ± 0.8mm, 6.6 ± 0.5mm, 8.4 ± 0.6mm, and 9.8 ± 0.5mm in the four directions. The area of detection was smallest for the antrum (83.7mm2) and similar for the other sites (150.6, 154.7 and 157.7mm2 for the upper body, thin colon, and thick colon, respectively). The distance at which the RFID tag was detected was usually within 10mm. These results indicate the feasibility of the clinical application of the add-on clip and RFID tag as a marker for identifying the location of various gastrointestinal tumors.

Changes in VIP-, SP- and CGRP- like immunoreactivity in intramural neurons within the pig stomach following supplementation with low and high doses of acrylamide

Acrylamide is one of the food toxins to which the human body is exposed. Although researchers’ interest in acrylamide has been growing in recent years, the knowledge of its effect on the gastrointestinal tract, especially on intramural neurons which form the enteric nervous system is scarce. The aim of this experiment was to determine the influence of acrylamide, administered at doses equivalent to the human tolerable daily intake (TDI, 0.5 μg/kg b.w./day) and ten times higher than the TDI (5 μg/kg b.w./day), on the distribution of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene related peptide (CGRP) in intramural neurons of the domestic pig stomach. Using double immunofluorescent labelling we revealed that the ENS neurons underwent adaptive changes in response to the supplementation of acrylamide, which manifested themselves as increased expression of VIP, SP and CGRP, both in intramural neurons and by an increase in the nerve density in submucous and muscular layers in the porcine stomach. These substances take part in defensive reactions of neurons and transmission of sensory reactions may play an important role in protecting the stomach against the harmful effect of acrylamide. Moreover, it has been shown that acrylamide induces a significant response of ENS neurons even in TDI dose, which suggests that it is not neutral to the body. These findings may be the basis for further toxicological studies addressing the question if currently permitted minimal content of acrylamide in the food does jeopardize the health of human consumers?

Quantification of in vivo gastric fluid volume in Bama miniature pigs in fasted state.

Although the study of bioequivalence waivers in humans is already well-established, their application and translation into animals, which are complicated by differences in physiology, have only recently become subjects of interest. The main purpose of this paper is to quantify the liquid volume affecting drug dissolution in pig stomachs. We used magnetic resonance imaging (MRI) to scan 18 Bama miniature pigs weighing 15, 30 or 50kg. Amira 6.0.1 software was used for 3D image processing. We found that the gastric fluid volume had a linear relationship with the weight of pig (R2 =0.9935) over this weight range. The pig weight, therefore, could be used as a surrogate for the fasted gastric fluid volume. After combining data of gastric fluid secretion and drinking water volumes, our results could be used as a reference for the evaluation of oral drug absorption in pigs.

Correlation between Different Helicobacter Morphotypes and Histological Changes in Pig Gastric Mucosa

Background: Two distinct morphologic types of bacteria which belong to the Helicobacter species, have been described in pigs: once or twice curved Helicobacter pylori-like bacteria (HLO) and the multicoiled, Gastrospirillum-like bacteria (GLO). The objective of this study was to determine the incidence of Helicobacter spp. using modified Giemsa stain and to define the relationship between presence of Helicobacter spp. and histopathological changes of gastric mucosa in pigs.Materials, Methods & Results: A total of 120 pig stomachs (60 from intensive and 60 from extensive breeding) were enrolled in this study and 240 fragments of fundic and pyloric mucosa were taken for histopathological examination. By modified Giemsa staining of gastric mucosa, Helicobacter-like organisms were confirmed in 4/60 (6.67%) of pigs in intensive and 5/60 (8.33%) of pigs in extensive breeding. The incidence of tightly spiral shaped Gastrospirillum-like organisms in pigs of intensive and extensive breeding were 5/60 (8.33%) and 9/60 (15%), respectively. The severity of gastritis was scored to the Sydney System with some modifications. There was no significant difference between HLO-positive and HLO-negative fundic mucosa in pigs of both breeding systems. In contrary, there was significant difference between HLO-positive and HLO-negative pyloric mucosa of pigs in intensive (P < 0.001) and in extensive breeding (P < 0.05). In intensive breeding, there was significant difference between GLO-positive and GLO-negative fundic mucosa (P < 0.05), while there was no significant difference between GLO-positive and GLO-negative pyloric mucosa.Discussion: The prevalence of Helicobacter spp. bacteria were in coherence with literature data. The higher prevalence of both morfological type of bacteria, were considered in pigs in extensive breeding. the hygienic conditions and managment factors in pigs farm are the possible impact for higher bacterial transmission. The association of high prevalence of H. pylori and poor hygienic condition was shown by epidemiological studies conducted on humans. In both, humans and pigs, the presence of H. pylori correlates with an inflammatory response, but there are differences in inflammatory cell population. In H. pylori infected humans, neutrophils composed the bulk of cellular infiltrate, while in pigs, the primary inflammatory cell was the lymphocyte, which is in accordance to results published by others autors. Thus it indicates that different hosts exhibit a different pathohistological response to the Helicobacter spp. infection. In human as well as in veterinary pathology, the fact of the different pathogenicity of various Helicobacter species is well known. In all HLO-positive pyloric mucosa, moderate to severe focal or diffuse infiltration of mononuclear cells and lymphoid follicles with germinal centers, were observed. A similar conclusion was drawn from results of an experimental infection study in pigs. There was signifficance between HLO-positive and HLO-negative pyloric mucosa in both, intensive and extensive breeding. In the contrast, GLO were not associated with the presence of severe gastritis, but only with mild to moderate superficial infiltration of lymphocytes and plasma cells in both, fundic and pyloric mucosa. There was no significant difference between GLO-positive and GLO-negative pyloric mucosa of pigs in both breeding systems. Despite the low gastritis score of fundic mucosa in pigs in intensive breeding, there was a significance difference between in GLO-positive and GLO-negative fundic mucosa. It is believed that the possible reason of such results is the meals with low fiber content and low particles size. These results suggest that the presence of HLO, but not of GLO is associated with the pyloric gastritis in pigs.

The Use of Simulation Technologies in the Formation of the Basic Skills of Videoendoscopic Surgery in Clinical Residents Enrolled in Training Programs for Surgical Specialists

Wide introduction of videoendosurgical technologies in all surgical specialties has become a challenge for teachers of medical universities. According to many authors, the use of virtual simulators proved to be unjustified, which compelled us to conduct a study to determine the place of virtual endosurgical simulators in the training program of a specialist of surgical profile. The experiment involved 36 clinical residents who took the training simulation course (108 hours) in the training virtual clinic (simulation training center) of VSMU N. N. Burdenko during 2016-2017. Students were divided into two groups. In the first group, classes were held on the Gross-SMITH simulators, equipped with simulators of laparoscopes ending with cameras with options axis angle 0 and 30 degrees. In the second group, classes were held on a virtual simulator with tactile backlink LapVR. At the end of the course, each resident was asked to do control exercise – to stitch pig's stomach, which had a wound with two markings indicating where to lead the needle. Videoendosurgical simulator Gross-SMITH was used to perform a control exercise. The results of the study confirmed the effectiveness of the use of virtual endosurgical simulators with tactile backlink in the formation of the basic skills of videoendoscopic surgery. The formation of the skill of tying an intracorporal knot proved to be more effective in training with the use of videoendosurgical simulators Gross-SMITH and real surgical instruments.

Real-time photoacoustic and ultrasonic dual-modality imaging system for early gastric cancer: Phantom and ex vivo studies

Photoacoustic (PA) and ultrasonic (US) imaging are promising techniques for imaging biological tissue and diagnosing internal organs. This paper presents a real-time PA and US dual-modality imaging system for early gastric cancer (EGC) based on a clinical US transducer. It has the advantage that only the PA excitation is inside the body but the US imaging system is outside the body, which makes the system less invasive for EGC detection and will be a potential tool for clinical use. The first experiments produced real-time PA images of blood vessel phantoms. Cross-sectional 2D PA images and reconstructed 3D PA images of the blood vessel phantoms demonstrate the system can clearly identity tissue structure. The experiments show that the system has a high axial spatial resolution but a relatively low lateral spatial resolution. The second experiments combining US and PA imaging, an artificial slightly elevated tumor and three artificial superficial flat tumors embedded inside the pig stomach mucosa ex vivo, demonstrate that the system is able to detect EGC accurately.

Pyrosequencing-based analysis of the complex microbiota located in the gastrointestinal tracts of growing-finishing pigs

The commensal gut microbial communities play an important role in the health and production efficiency of growing-finishing pigs. This study aimed to analyse the composition and diversity of the microbiota in the gastrointestinal tract sections (stomach, duodenum, jejunum, ileum, caecum, colon and rectum) of growing-finishing pigs. This analysis was assessed using 454 pyrosequencing targeting the V3–V6 region of the 16S rRNA gene. Samples were collected from 20, healthy pigs aged 24 weeks and weighing 115.9 ± 5.4 kg. The dominant bacterial phyla in the various gastrointestinal tract sections were Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria. At the genus level, Prevotella, unclassified Lachnospiraceae, Ruminococcus, unclassified Ruminococcaceae and Oscillospira were more abundant in the large intestine than in the stomach and the small intestine. Unclassified Peptostreptococcaceae and Corynebacterium were more abundant in the small intestine than in the stomach and the large intestine. Shuttleworthia, unclassified Veillonellaceae and Mitsuokella were more abundant in the stomach than in the small and large intestines. At the species level, M. el.s.d.enii and M. multacida were predominant in the stomach. In addition, P. stercorea, P. copri, C. butyricum, R. flavefaciens and R. bromii were significantly more abundant in the large intestine than in the stomach and the small intestine. B. pseudolongum and B. thermacidophilum were significantly more abundant in the small intestine than in the stomach and the large intestine. Principal coordinates analysis showed that the overall composition of the pig gastrointestinal microbiota could be clustered into three groups: stomach, small intestine (duodenum, jejunum and ileum) and large intestine (caecum, colon and rectum). Venn diagrams illustrated the distribution of shared and specific operational taxonomic units among the various gastrointestinal tract sections.

Sa1057 THREE-DIMENSIONAL UPPER GASTROINTESTINAL ENDOSCOPY: A CLINICAL STUDY OF SAFETY AND AN EX VIVO STUDY OF UTILITY IN ENDOSCOPIC SUBMUCOSAL DISSECTION

The utility of three-dimensional (3D) endoscopy in the field of therapeutic endoscopy was investigated ex vivo using a newly developed 3D endoscope. Also, we conducted a clinical study to investigate the safety of 3D endoscopy as an upper gastrointestinal (GI) screening tool in actual clinical practice using the 3D endoscope, which had recently been approved as a medical device. To investigate the utility of this 3D endoscope in therapeutic endoscopy, an excised pig stomach with a 10-mm hypothetical lesion was attached to an endoscopic training simulator. The outcomes of endoscopic submucosal dissection (ESD) performed under two-dimensional (2D) and 3D conditions were compared based on the rate of en bloc resection, incidence of perforation, time required for circumferential incision and resection, and severity of eyestrain based on the symptoms of eyestrain, eye pain, blurred vision, heavy-headedness, and headache. Severity of eyestrain was evaluated before and after ESD using a visual analog scale (VAS; 0–100 mm). Eight endoscopists each performed ESD on 4 hypothetical lesions (2 lesions each for 2D and 3D endoscopy). A clinical study was conducted to investigate the safety of 3D endoscopy in 60 patients (36 men, 24 women; mean age 59.3 years) who had given written informed consent to participate in the study. We evaluated the severity of eyestrain in endoscopists before and after each endoscopic procedure, by using the VAS. All 32 lesions were resected en bloc. Perforation was observed in one 2D case. Circumferential incision time was significantly shorter in the 3D group than in the 2D group (102.8 ± 42.1 vs. 135.8 ± 65.7, respectively; p < 0.05), as was resection time (366.3 ± 187.6 s vs. 517.8 ± 282.3 s, respectively; p < 0.05). Intergroup comparisons revealed that the severity of eyestrain-related symptoms, except for blurred vision, was significantly higher in the 3D group than in the 2D group. In the clinical study, none of the 60 patients developed adverse events such as bleeding and perforation, demonstrating the safety of 3D endoscopy. Severity of eyestrain in the endoscopists was significantly higher for all items, except for headache, after endoscopic procedure. Resection time was significantly shorter in 3D ESD than in 2D ESD. Also, 3D ESD was performed safely, with no incidence of perforation. These findings suggest that 3D endoscopy enables rapid and stable ESD because of easy recognition of structures and acquisition of depth information. Furthermore, in the clinical study, 3D endoscopy was performed safely, with no occurrence of severe adverse events.

Molecular evidence of Helicobacter suis infection in pigs in Nigeria

Helicobacter suis mainly colonizes the stomach of pigs and occasionally infects humans. It is a prevalent cause of gastritis and gastric ulcers in both species. This study was designed to determine the colonization rate of H. suis in the stomach of pigs in Nigeria. Pig slaughter house surveys were conducted and stomach mucosa samples were collected from the fundus of the stomach of a total of 160 pigs in four locations in Nigeria (Lagos, Delta, Enugu and Plateau States). In each location, 50% of the samples were collected from stomachs with ulceration in the fundus, while the rest were from those with no gross lesions. DNA was extracted and PCR assay was conducted using standard primers. Data was analyzed by descriptive statistics and Chi-square test (p< 0.05). H. suis was detected in 8.75% of the samples across the four locations at a frequency of 15, 7.5, 10 and 2.5% in Lagos, Delta, Enugu and Plateau states, respectively. H suis was detected in 12.5 and 5% of the stomachs with ulcers and without ulcers, respectively. H suis colonizes pigs in Nigeria at a relatively low rate with its colonization rate being higher in stomachs with ulcers. There is need for characterization of the strains of the organism in Nigeria for a better understanding of its possible role in gastric ulceration in pigs. Key words: Gastric ulcer, Helicobacter suis, pigs, stomach.

Phenylalanine and tryptophan stimulate gastrin and somatostatin secretion and H+-K+-ATPase activity in pigs through calcium-sensing receptor

In rodents and humans, aromatic amino acids increase gut hormone secretion and H+-K+-ATPase activity by modulating calcium-sensing receptor (CaSR). However, the role of CaSR and its related signaling molecules in amino acid-induced gut hormone secretion in swine has not been investigated. Here, we examined whether a CaSR-dependent pathway modulated gastrin and somatostatin (SS) secretion and H+-K+-ATPase activity in pigs. Perfusion of pig stomach tissues in the presence of extracellular 80 mM l-phenylalanine (Phe) or 20 mM l-tryptophan (Trp) and a CaSR agonist cinacalcet triggered gastrin and SS secretion and H+-K+-ATPase activity (P < 0.05) and increased CaSR expression (P < 0.05). This effect of Phe and Trp was dependent on Ca2+ (P < 0.05) and was abolished after treatment with NPS 2143, an inhibitor of CaSR, and 2-aminoethyl diphenyl borinate, an inhibitor of CaSR downstream signaling molecule inositol 1,4,5-triphosphate receptor (IP3R). These findings indicate that Phe and Trp induce Ca2+-dependent gastrin and SS secretion and H+-K+-ATPase activity through CaSR and its downstream signaling molecule IP3R.

Helicobacter suis binding to carbohydrates on human and porcine gastric mucins and glycolipids occurs via two modes

ABSTRACT Helicobacter suis colonizes the stomach of most pigs and is the most prevalent non-Helicobacter pylori Helicobacter species found in the human stomach. In the human host, H. suis contributes to the development of chronic gastritis, peptic ulcer disease and MALT lymphoma, whereas in pigs it is associated with gastritis, decreased growth and ulcers. Here, we demonstrate that the level of H. pylori and H. suis binding to human and pig gastric mucins varies between individuals with species dependent specificity. The binding optimum of H. pylori is at neutral pH whereas that of H. suis has an acidic pH optimum, and the mucins that H. pylori bind to are different than those that H. suis bind to. Mass spectrometric analysis of mucin O-glycans from the porcine mucin showed that individual variation in binding is reflected by a difference in glycosylation; of 109 oligosaccharide structures identified, only 14 were present in all examined samples. H. suis binding to mucins correlated with glycans containing sulfate, sialic acid and terminal galactose. Among the glycolipids present in pig stomach, binding to lactotetraosylceramide (Galβ3GlcNAcβ3Galβ4Glcβ1Cer) was identified, and adhesion to Galβ3GlcNAcβ3Galβ4Glc at both acidic and neutral pH was confirmed using other glycoconjugates. Together with that H. suis bound to DNA (used as a proxy for acidic charge), we conclude that H. suis has two binding modes: one to glycans terminating with Galβ3GlcNAc, and one to negatively charged structures. Identification of the glycan structures H. suis interacts with can contribute to development of therapeutic strategies alternative to antibiotics.