Gastric Pits Research Articles

Evaluation of the lower histologic threshold for gastric graft versus host disease.

Data regarding the lower diagnostic threshold for gastric graft-versus-host disease is lacking. The aim of this study was to review a cohort of gastric biopsies taken to evaluate for graft-versus-host disease, and to correlate histologic findings with clinical and endoscopic evidence of graft-versus-host disease as well as biopsy findings from other locations to define a lower diagnostic threshold for gastric graft-versus-host disease. Gastric biopsies were evaluated for the maximum number of apoptotic bodies per 10 contiguous gastric pits, presence of ≥1 apoptotic body per biopsy (NIH criteria), and presence of gastric pit dropout and/or ulceration. To evaluate histologic specificity, sixty gastric biopsies from non-stem cell transplant patients were selected as a control group. Clinical information was collected from chart review. The study group consisted of 65 gastric biopsies from 52 stem cell transplant patients. The mean apoptotic count per 10 contiguous gastric pits for stem cell transplant biopsies was 1.8 (range 0-8) and for control cases 1.0 (range 0-5). Nineteen stem cell transplant biopsies (29%) had ≥1 apoptotic body per biopsy and only a single case had >6 apoptotic bodies per 10 contiguous gastric pits. When the NIH guidelines were combined with presence of at least two apoptotic bodies per 10 contiguous gastric pits, this cutoff point was significantly associated with treatment for graft-versus-host disease (OR = 9.4, 95% CI = 1.7-176.7, p = 0.04) and evidence of extraintestinal graft-versus-host disease (OR = 3.2, 95% CI = 1.1-10.7, p = 0.04). The diagnostic specificity for our proposed cutoff value is 94%. We present criteria for the lower diagnostic threshold of gastric graft-versus-host disease, which uses a lower apoptotic cutoff value than has been utilized in colonic biopsies. Although sensitivity remains a challenge for gastric graft-versus-host disease biopsies, this newly proposed cutoff provides higher specificity than NIH guidelines alone and better correlates with clinical evidence of graft-versus-host disease.

Gastrointestinal endoscopy in early diagnosis and treatment of gastrointestinal tumors.

Objective:To explore the value of gastrointestinal endoscopy in the early diagnosis and treatment of gastrointestinal tumors and lay a foundation for the diagnosis and treatment of gastrointestinal tumors.Methods:One hundred and eight patients with gastrointestinal tumors who were admitted to our hospital from August 2016 to April 2018 were retrospectively analyzed and divided into observation group and control group according to different diagnostic methods, 54 cases in each group. The control group was treated with traditional endoscopy (white light imaging) and traditional surgery, while the observation group underwent narrow band imaging (NBI) based on endoscopic examination and endoscopic mucosal resection. The image quality scores (morphological image, gastric pit image and capillary image), diagnostic accuracy, surgery related clinical indicators (operation time, intraoperative bleeding volume, hospitalization days) and complications were observed and compared between the two groups.Results:The morphological image, gastric pit image and capillary image scores of the observation group were higher than those of the control group (P<0.05). The diagnostic accuracy rate of the observation group was 96.30%, which was significantly higher than 75.93% (P<0.05). The operation time and hospitalization days of the observation group were shorter than those of the control group, and the intraoperative bleeding volume of the observation group was less than that of the control group; the differences were statistically significant (P<0.05). The incidence of complications of the observation group was lower than that of the control group, and the difference was statistically significant (P<0.05).Conclusion:Gastrointestinal endoscopy can accurately identify the pathological changes of tumors in the early diagnosis and treatment of gastrointestinal tumors, improve the diagnostic accuracy rate, and guide the implementation of treatment measures to improve clinical indicators. Moreover the incidence of postoperative complications is low. It is worth clinical promotion.

Distribution of aquaporins and sodium transporters in the gastrointestinal tract of a desert hare, Lepus yarkandensis

Lepus yarkandensis is a desert hare of the Tarim Basin in western China, and it has strong adaptability to arid environments. Aquaporins (AQPs) are a family of water channel proteins that facilitate transmembrane water transport. Gastrointestinal tract AQPs are involved in fluid absorption in the small intestine and colon. This study aimed to determine the distribution of AQPs and sodium transporters in the gastrointestinal tract of L. yarkandensis and to compare the expression of these proteins with that in Oryctolagus cuniculus. Immunohistochemistry was performed to analyse the cellular distribution of these proteins, and the acquired images were analysed with IpWin32 software. Our results revealed that AQP1 was located in the colonic epithelium, central lacteal cells, fundic gland parietal cells, and capillary endothelial cells; AQP3 was located in the colonic epithelium, small intestinal villus epithelium, gastric pit and fundic gland; AQP4 was located in the fundic gland, small intestinal gland and colonic epithelium; and epithelial sodium channel (ENaC) and Na+-K+-ATPase were located in the epithelial cells, respectively. The higher expression levels of AQP1, AQP3, ENaC and Na+-K+-ATPase in the colon of L. yarkandensis compared to those in O. cuniculus suggested that L. yarkandensis has a higher capacity for faecal dehydration.

3240 Cytomegalovirus Gastritis in an Immunocompetent Patient

INTRODUCTION: Cytomegalovirus (CMV) is a large enveloped virus of the Herpes virus family. CMV frequently infects humans and can establish latent infection after an acute infection. In immune-compromised patients, CMV can have neurological, cutaneous, gastrointestinal (GI), cardiac or ocular manifestations and can cause severe organ dysfunction leading to significant morbidity and mortality. The colon and the stomach are the common sites of GI infection. CASE DESCRIPTION/METHODS: 54 year old female with no prior medical history presented to the hospital with complaints of shortness of breath for the last 3 days and was noted to be in rapid atrial fibrillation. Patient was admitted and subsequently found to have severe mitral valve stenosis and moderate to severe tricuspid regurgitation. The patient was seen by Cardio-thoracic surgery and underwent mitral valve replacement and tricuspid ring annuloplasty. During the post-operative period, the patient was found to have blood in her stool and was evaluated by the gastroenterology service. In evaluating her GI bleed, she underwent an upper endoscopy. Findings on upper endoscopy included, small hiatus hernia and a single small ulcer in the incisura of the stomach. An area of gastritis was found in the antrum/body of the stomach. The mucosa appeared nodular and edematous. Biopsies were taken from the antrum and showed gastric antral type mucosa with reactive gastropathy. CMV viral inclusions were present in the gastric pit epithelial cells, confirmed on immunostain for CMV. HIV and quantiferon gold tests were negative and the patient was not known to be on any immunosuppressive therapies. Serum CMV DNA PCR was tested on 2 subsequent days which showed 4858 IU/ml and 5548 IU/mL respectively. DISCUSSION: CMV infection of the GI tract is a common manifestation of CMV disease in the immunocompromised patients such as Acquired immunodeficiency syndrome, organ/ bone marrow transplantation and other condition requiring chronic immunosuppressive therapy. CMV of the GI tract is rare in an immunocompetent patient and only few cases have been reported so far. Presenting symptoms include odynophagia/dysphagia, epigastric pain, nausea/vomiting, GI bleeding. However, in up to 7% of cases it can be asymptomatic. Endoscopic features of CMV infection include macroscopic normal mucosa, diffuse erythema, nodules, pseudotumors, erosions and ulcers. Detection of intranuclear inclusions, also known as “owl's eye,” is the hallmark of CMV infection.

Comparative Histological Study of the Stomach in Two Species of Iraqi Vertebrates (Magpie Pica pica L. and Small Asian Mongoose Herpestes javanicus E.)

A histological study showed the wall of the stomach in Pica pica and Herpestes javanicus consists of four layers: mucosa, submucosa, muscularis externa and serosa. Also, the present study showed many differences in the histological structures of the stomach for each in both types. The stomach of P. pica consists of two portions: the proventiculus and gizzard, while the stomach of H. javanicus consists of three portions: cardiac, fundic and pyloric regions. The mucosa layer formed short gastric folds, named plicae. In the proventiculus of P. pica, sulcus is found between each two plicae, but the folds called gastric pits in the gizzard, which are full with koilin. Lamina properia in both types contained gastric glands (straight simple tubular glands) named superficial glands, as well as another gastric gland found in the submucosa layer of the proventiculus in P. pica only named deep gastric glands. The gastric gland in the stomach of H. javanicus contained: mucous neck cells and parietal cells positive to AB/PAS stains in cardiac portion, as well as chief cells in fundic portion, but pyloric portion had just mucous neck cells. Muscularis externa in both types formed two muscle layers: inner and outer layer.

Comparative Histological Study of the Stomach in Two Species of Iraqi Vertebrates (Magpie Pica pica L. and Small Asian Mongoose Herpestes javanicus E.)

A histological study showed the wall of the stomach in Pica pica and Herpestes javanicus consists of four layers: mucosa, submucosa, muscularis externa and serosa. Also, the present study showed many differences in the histological structures of the stomach for each in both types. The stomach of P. pica consists of two portions: the proventiculus and gizzard, while the stomach of H. javanicus consists of three portions: cardiac, fundic and pyloric regions. The mucosa layer formed short gastric folds, named plicae. In the proventiculus of P. pica, sulcus is found between each two plicae, but the folds called gastric pits in the gizzard, which are full with koilin. Lamina properia in both types contained gastric glands (straight simple tubular glands) named superficial glands, as well as another gastric gland found in the submucosa layer of the proventiculus in P. pica only named deep gastric glands. The gastric gland in the stomach of H. javanicus contained: mucous neck cells and parietal cells positive to AB/PAS stains in cardiac portion, as well as chief cells in fundic portion, but pyloric portion had just mucous neck cells. Muscularis externa in both types formed two muscle layers: inner and outer layer.

HISTOCHEMICAL ANALYSIS OF STOMACH OF GRASSCUTTER (Thryonomys swinderianus)

The Grasscutter (Thryonomys swinderianus), is a wild herbivorous rodent peculiar to Africa. It is widely eaten in Nigerian rural communities as a protein source hence its domestication as microlivestock. There is paucity of data on the histochemical studies. This study was aimed at histochemically analyzing the stomach in order to determine if it exhibits regional differences in its qualitative expression of acid, neutral and carboxylated mucin. Seven animals obtained from the wild and domesticated in the animal house of the Department of Human Anatomy, Ahmadu Bello University, Zaria were used. Histologically, stomach of the Grasscutter was simple, glandular and composed of three regions: cardia, fundic‐body and pyloric. Cardia region showed enlongated tubular glands, coiled at the lower end with an opening continuous with the long conspicuous gastric pits. Fundic‐body region showed numerous gastric glands which open into fewer shorter gastric pits while the pyloric region showed simple tubular glands which are highly branched as such obscures the depth of the gastric pits. Histochemically, stomach of the Grasscutter exhibits regional polymorphism in the mucin content with the glands showing weak alcianophilic reactions. Cardia and pyloric regions demonstrated neutral periodic acid Schiff (PAS) reaction characterized by purple coloration thus indicating the presence of neutral mucins. Fundic‐body region exhibited strong PAS positive reaction particularly at the apical cytoplasm of the oxynticopeptic cells indicating the presence of carboxylated mucins. Results demonstrate that regional differences in the expression of mucins occur in the stomach of African Grasscutters, thus this may provide basic information for further nutritional and conservative studies.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Morphofunctional Characteristics of the Stomach Exposed to Sodium Tetraborate

The aim is to study the morphological and functional characteristics of the gastric mucosa of rats exposed to sodium tetraborate.Material and methods. The object of the study were the stomachs of 50 white male mongrel rats. The animals were divided into 2 groups. Animals of the 1st group once intragastrically through the probe entered the borax in the dose of LD50– 5000 mg/kg. Animals of the second group intragastrically through a tube daily introduced sodium tetraborate at a dose of 1/10 LD50– 500 mg/kg. the Animals of the 1stgroup were withdrawn from the experiment in a day after single administration of sodium tetraborate, animals of the 2ndgroup – 7, 14, 21 and 30 days after the start of the experiment. The obtained material was treated using histological, histochemical and immunocytochemical methods.Results. With a single and long-term exposure to sodium tetraborate in the gastric mucosa against the background of edema, stagnation of blood elements in the blood vessels of the microcirculatory bed, moderate leukocyte infiltration, there was focal desquamation of the epithelium, numerous destructive changes in the cover and glandular cells of the gastric mucosa, a significant death of epithelial cells, accompanied by a decrease in the secretory function of mucous cells. Destructive changes are more pronounced at a higher dose of sodium tetraborate. Damage to epithelial cells lead to an increase in the zone of proliferative activity of the epithelium of the mucous membrane (mitoses are noted not only in the neck of the gland, but also in the body of the gland and in the epithelium of gastric pits). In the own plate of the mucous membrane there is an increase in the activity of fibroblasts.Conclusion. The data obtained indicate a negative impact of the used doses of sodium tetraborate. The expansion of the zone of proliferative activity of the epithelium of the mucous membrane of the stomach, aimed at the restoration of structural homeostasis, is not fully offset with a significant destruction of epithelial and glandular cells. The increase in the activity of fibroblastic differon cells indicates their greater resistance to the negative effects of sodium tetraborate in comparison with epithelial cells.

Morphology of the Stomach of Tayra (Eira barbara)

Background: The Tayra (Eira barbara) is a mammal of the family Mustelidae with a significant presence in Latin America, it is considered an opportunist and extremely agile omnivorous. Some organs compose the digestive system and the stomach is a substantial organ for this system. The stomach have a small and a large curvature and the regions of the cardia, fundus, body and pylorus. Histologically, the stomach is made up of four layers or tunics that contributes in digestive functions. However, due the limited information available in the literature about morphophysiology of wildlife, this study aimed to clarify the morphology of Eira barbara stomach to understand your digestive system.Materials, Methods &amp; Results: Three males and three females of Eira barbara species were studied (all young adults), all samples were originated of the Bauxite Mine area, in Paragominas, Pará state, Brazil provided of donation to Morphological Animal Research Laboratory (LaPMa) of the Universidade Federal Rural da Amazonia (UFRA), after death by trampling. The corpses were treated with aqueous 10% formaldehyde solution intramuscular injections, subcutaneous and intracavitary. After dissection, the collected material was processed following histologic standard protocols for the subsequent preparation of slides. The studied animals showed the stomach on the left antimere the abdominal cavity, with saccular format with the presence of large and small curvatures. The organ showed composite mucosa made with various gastric folds distributed in regions of the cardia, fundus and pylorus. A microscopic analysis of Eira barbara stomach revealed the presence of tunics or layers which gradually invaginate the lumen of the organ and underlying lamina propria was located to the prismatic epithelium and muscular mucosae and mucosa itself. In the region of the cardia, the muscle layer was deeply situated on the lamina propria, consisting of smooth muscle tissue with circular and longitudinal fibers. The submucosa consists of loose connective tissue; it is much thicker than the lamina propria and has many vessels. The first portion of the stomach showed long glands, while with short pits. In light microscopy, the fundic region revealed the presence of a highly pleated epithelium with elongated glands composed of clear and basally placed cells, with flattened nuclei. These cells are named mucous. Along the short region of the gastric pits, the presence of large cells was reported, pyramidal or rounded, central nucleus, called parietal. The pyloric region microscopy revealed the presence of short glands, similar to those previously described in the cardia region. The wide presence of goblet cells in the final portion of the pylorus indicated gradual transition between the regions of the stomach to the intestine, called duodenum-pylorus transition. The muscular layer showed thick muscle bundles just in circular direction, being responsible for the formation of the pyloric sphincter.Discussion: The morphological analysis of the stomachs showed morphological and topographical similarities to the literature description for pets and wild mammals, however, were found in abundant quantities goblet cells in the transition duodenal pylorus. The goblet cells are located throughout the length of the small and large intestine and are responsible for the production and maintenance of the protective mucus synthesizing as glycoproteins known as mucins.

Breaking Out From Tradition: Redesign of Large Physiology Lecture Increases Engagement, Inclusion, and Student Outcomes

Mounting evidence suggests that traditional lecturing is less effective, less engaging, and less inclusive than active learning. However, transitioning to active learning, particularly in a large science course, presents unique administrative and pedagogical challenges. In this study, we present the results of our recent effort to redesign and restructure our large human anatomy and physiology course at the University of Connecticut.In place of a traditional lecture, we developed an active instructional model that subdivided hundreds of students into “break out” groups of no more than five students. Breakout groups met concurrently in multiple classrooms during the scheduled lecture time to work through modules in the renal and digestive systems with an undergraduate peer facilitator. Modules were designed with input from undergraduate facilitators, with attention to scientific teaching techniques (active learning, inclusive teaching, assessment). Students concept mapped the molecular basis of urine formation in nephrons and the regulation of acid secretion in the gastric pit; worked through an interrupted case study on ulcer formation and modified think‐pair‐share question sets on renal and gastric pharmacology; and practiced critical reflection on the clinical and socioeconomic factors influencing the incidence and treatment of disease.At the end of the semester, students registered in the redesigned course were compared to peers registered in another section, taught by the same instructors, that followed a traditional large lecture format. This assessment involved an analysis of student performance on paired exam questions of varied difficulty, a modified SALG (Student Assessment of Learning Gains), and solicited and unsolicited student feedback. Our results indicate that, on average, students in the redesigned course performed better on exam questions related to the renal and digestive systems. Furthermore, many of these questions were found to be less “discriminating”, indicating less disparity between higher performing and lower performing students. The vast majority (95%) of students gave positive feedback on the redesigned classes, and nearly 90% reported learning gains related to the major concepts from the digestive and renal system. Summarily, our study describes and evaluates a new instructional model for large, undergraduate anatomy and physiology courses that has been developed and implemented using undergraduate students. Most importantly, we offer preliminary evidence supporting the conclusion that this model is more inclusive, more effective, and better liked than traditional lecturing.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

DEC205 mediates local and systemic immune responses to Helicobacter pylori infection in humans.

Helicobacter pylori infections cause gastritis and affect systemic immune responses; however, no direct association between immune cells and stomach bacteria has yet been reported. The present study investigated DEC205-mediated phagocytosis of H. pylori and the role of DEC205-positive macrophages in the human gastric mucosa. DEC205 mediated phagocytosis of H. pylori was detected immunocytochemically in PMA-stimulated macrophages differentiated from NOMO1 cells. Expression of DEC205 mRNA in peripheral blood mononuclear cells (PBMCs) from H. pylori-infected patients was analyzed following stimulation with H. pylori cell lysate. We found that anti-DEC205 antibodies inhibited phagocytosis of H. pylori. The number of cells double-positive for DEC205 and CD14 in human gastric mucosa was higher in H. pylori-infected patients. DEC205-positive macrophages invaded the extracellular space between epithelial cells within gastric pits. In addition, DEC205 mRNA expression was upregulated in human PBMCs stimulated with H. pylori lysate. These findings suggest DEC205-expressing macrophages are important for recognition of H. pylori in human gastric mucosa, which affects systemic immunity.

Some Histological and Scanning Electron Microscopic Studies on The Gizzard of Turkey

This research was designed to study the histological characteristics of gizzard in turkey by light and scanning electron microscopes. The study was performed on ten healthy mature birds of turkey. The specimens were immediately removed after slaughter, gently cleaned and fixed in 10% buffered neutral formalin then processed for light and scanning microscopic studies. The histological observations revealed that as other species of birds the turkey gizzard was consisted of four tunics; mucosa, sumbucosa, musculosa and serosa. Thick layer of cuticle was lined the gizzard mucosa which contains gastric pits. The lamina epithelialis lined with simple cuboidal epithelium, the lamina propria contained simple tubular glands which arranged in groups. These glands are lined by simple cuboidal epithelium. The inner part of these tubular glands contains an eosinophilic secretion. PAS positive material distribute nearly in almost region. It was within the lumen of the glands, within the cells lining the surface and crypts, Also, within the deep glandular cells. The submucosa consists of connective tissue formed mainly from collagen fibers. The tunica muscularis was very thick formed from parallel bundles of smooth muscle fibers, these bundles separated by thin layer of connective tissue. Scanning electron microscopic observations revealed that the surface of the koilin cuticle was very thick and appeared in form of clusters separated by grooves resembling the cracked ground appearance. These clusters were in the form of rodlets.

Neoplastic Lesions of Gastric Adenocarcinoma and Proximal Polyposis Syndrome (GAPPS) Are Gastric Phenotype.

(1) the spectrum of gastric pathology associated with GAPPS is wider than previously reported, (2) the earliest microscopic clue is the finding of hyperproliferative aberrant pits, and (3) the dysplasia is gastric phenotype and the subsequent adenocarcinoma may follow the gastric pathway of carcinogenesis.

Evaluation of antioxidant and gastroprotective activities of ethyl acetate extract of Avicennia schaueriana.

Introduction: Brazilian flora has a great biodiversity and some of these plants are used in folk medicine. Avicennia schaueriana, popularly known as black mangrove, is an endemic specie of mangrove vegetation belonging to the Acanthaceae family. The species of the genus Avicennia are widely used by traditional communities for the treatment of tumors, rheumatism, ulcers and wound healing. Objectives: To evaluate the antioxidant and gastroprotective properties of the ethyl acetate extract of Avicennia schaueriana. Methodology: The ethyl acetate extract of the leaves of A. schaueriana (As-AcEOt) was obtained by maceration, and afterwards the phytochemical prospecting was evaluated by thin layer chromatography (TCL). The antioxidant potential of the As-AcEOt was evaluated by free radical scavenging method ABTS+ (2,2-azobis – (3-ethylbenzthiazoline-6-sulfonate). The gastroprotective activity of As-AcEOt (50, 100 and 200 mg/kg) was analyzed by the ethanol-induced ulcer method in Wistar rats. The myeloperoxidase (MPO) levels and histopathological analysis were evaluated in gastric mucosa of the animals treated with As-AcEOt submitted to the model of ulcer induced by ethanol. Results and Discussion: Through TCL was observed the presence of terpenoids, flavonoids and tannins in the extract. The As-AcEOt exhibited antioxidant activity with 73.23% inhibition of the radical ABTS+. In the gastroprotective activity, the As-AcEOt reduced the ulcerative lesion index (ULI), with percentages of ULI of 83.8, 88.5 and 86.9% for the doses of 50, 100 and 200 mg/kg, respectively. The histological analysis showed that As-AcEOt preserved the gastric pits and it did not present hemorrhage and edema. Conclusion: This research showed that As-AcEOt has gastroprotective property, which may be related to antioxidant capacity of the phenolic compounds present in the extract. These results corroborate with the indication of popular use of this species in the treatment of gastric ulcers.

Protective role of Phoenix dactylifera fruit against ethanol-induced gastric ulcer in Wistar rats

Background: Peptic ulcers are gastrointestinal lesions that occur in the stomach and duodenum as a result of ethanol consumption, Helicobacter pylori infection and use of non-steroidal anti-inflammatory drugs. Methods: Twenty Wistar rats were divided into four groups and fasted for 18 hours. Rats in groups 1, 2, 3 and 4 were pretreated with normal saline, gestid suspension and Phoenix dactylifera ( P. dactylifera ) extract at 250 & 500 mg/kg respectively, they were given 80% ethanol after 30 minutes. They were all sacrificed after an hour and the stomachs were dissected and opened, pH of stomach content was determined. The stomachs were examined using hand lens for macroscopic lesions, they were fixed in 10% formalin and processed for light microscopic study. Results: There was significant decrease in pH of stomach content of rats pre-treated with P. dactylifera extract as compared to those of rats pre-treated with normal saline, the ulcer index (UI) decrease significantly in rats pre-treated with P. dactylifera extract as compared to those of rats pre-treated with normal saline, but a significant increase compare to those of rats pre-treated with gestid suspension. The gastric mucosa of rats pre-treated with normal saline is full of lesions while those of rats pre-treated with gestid suspension and P. dactylifera extract showed few mild and moderate lesions. Photomicrograph of stomach of rats pre-treated with normal saline showed distortion of submucosa, loss of luminal epithelium and weakness of muscularis mucosa, those of rats pre-treated with gestid suspension and P. dactylifera extract at 250 mg/kg showed normal muscularis mucosa and blood vessels while those of rats pre-treated with P. dactylifera extract at 500 mg/kg showed distortion of mucosal layers within the gastric pits. Conclusions: P. dactylifera extract was able to protect the stomach from ethanol-induced gastric ulceration in Wistar rats.

Abomasal dysfunction and cellular and mucin changes during infection of sheep with larval or adult Teladorsagia circumcincta.

This is the first integrated study of the effects on gastric secretion, inflammation and fundic mucins after infection with L3 T. circumcincta and in the very early period following transplantation of adult worms. At 3 months-of-age, 20 Coopworth lambs were infected intraruminally with 35,000 L3; infected animals were killed on Days 5, 10, 15, 20 and 30 post-infection and 6 controls on either Day 0 or 30 post-infection. Another 15 Romney cross lambs received 10,000 adult worms at 4–5 months-of-age though surgically-implanted abomasal cannulae and were killed after 6, 12, 24 and 72 hours; uninfected controls were also killed at 72 hours. Blood was collected at regular intervals from all animals for measurement of serum gastrin and pepsinogen and abomasal fluid for pH measurement from cannulated sheep. Tissues collected at necropsy were fixed in Bouin’s fluid for light microscopy, immunocytochemistry and mucin staining and in Karnovsky's fluid for electron microscopy. Nodules around glands containing developing larvae were seen on Day 5 p.i., but generalised effects on secretion occurred only after parasite emergence and within hours after transplantation of adult worms. After L3 infection, there were maximum worm burdens on Days 10–15 post-infection, together with peak tissue eosinophilia, inhibition of gastric acid secretion, hypergastrinaemia, hyperpepsinogenaemia, loss of parietal cells, enlarged gastric pits containing less mucin and increased numbers of mucous neck cells. After adult transplantation, serum pepsinogen was significantly increased after 9 hours and serum gastrin after 18 hours. Parallel changes in host tissues and the numbers of parasites in the abomasal lumen suggest that luminal parasites, but not those in the tissues, are key drivers of the pathophysiology and inflammatory response in animals exposed to parasites for the first time. These results are consistent with initiation of the host response by parasite chemicals diffusing across the surface epithelium, possibly aided by components of ES products which increased permeability. Parietal cells appear to be a key target, resulting in secondary increases in serum gastrin, pit elongation, loss of surface mucins and inhibition of chief cell maturation. Inflammation occurs in parallel, and could either cause the pathology or exacerbate the direct effects of ES products.

Anatomical , histological and histochemical studies of digestive tract of fish Mastacembelus mastacembelus

The present study involves anatomical comparsion, histological and histochemical structures of digestive tract ofMastacembelusmastacembelus (carnivore) at the level of light microscope hematoxylin and eosin , mallory's triple , periodic acid schiff (PAS) , and alician blue stains (PH1and PH2) were use . The anatomical Results revealed cylindrical muscular tube esophagus connecting pharynx , directly to cardic stomach of M. mastacembelus .The stomach shape is cystoid with cardic, fundic and pyloric portions . Pyloric caeci absent in M. Mstacembelus.intestine is shortest, relative length (RGL) is (0.58) , (S) letter shape and not coiled . Histologically the esophagus of M. Mstacembelus composed of two parts, anterior and posterior parts .The stomach has cardic , fundic and pyloric portions while intestine divided into four parts, proximal , middle, distal and anus .The arrangement and number of strata forming digestive wall from esophagus up to anus is similar in studied fish , involving four basic layers (mucosa , submucosa , mascularis and serosa) . Tunica muscularis along the digestive canal consist of two smooth muscle layers inner (circuler) and outer (longitudinal) expectesophagus which included stratified muscle layers . Many mucosal folds were lining digestive tract. These folds become crowded, very long and branched along all intestinal divisions and then become very short in anus . Tunica mucosa consist of simple columnar epithelium lining G.I from esophagus to anus . Goblet cells present among esophageal, intestinal and anal mucosal epithelium . They are numerous along esophagus and posterior intestine . Lamina propria directly under mucosal epithelium consists of thick layer of Connective tissue present in anterior esophagus, stomach and intestine . Lamina propria contain great amount of gastric glands consist of oval or spherical secretory unit lined by one type of pyramedial cell. Posterior stomach mucosal surface contains great amount of gastric pit. muscularis mucosa absent in M. mastacembelus. Tunica submucosa along digestive canal of studied fish consist of thin areolar connective tissue and collection of lymphatic cells similar to lymphatic follicle seen in anterior intestine . G.I serosa layer consist of connective tissue covered bymesotheliur. This study showed the presence of different amounts and types of mucous material in different G.I regions . positive tissue reaction with PAS, AB1, AB2 ensure presence of mucous material . Tissue reaction with PAS was very strong in esophagus and intestine while it was strong in stomach while tissue reaction withAB2 was moderate in esophagus, stomach and intestine .

A physics-based model for maintenance of the pH gradient in the gastric mucus layer.

It is generally accepted that the gastric mucus layer provides a protective barrier between the lumen and the mucosa, shielding the mucosa from acid and digestive enzymes and preventing autodigestion of the stomach epithelium. However, the precise mechanisms that contribute to this protective function are still up for debate. In particular, it is not clear what physical processes are responsible for transporting hydrogen protons, secreted within the gastric pits, across the mucus layer to the lumen without acidifying the environment adjacent to the epithelium. One hypothesis is that hydrogen may be bound to the mucin polymers themselves as they are convected away from the mucosal surface and eventually degraded in the stomach lumen. It is also not clear what mechanisms prevent hydrogen from diffusing back toward the mucosal surface, thereby lowering the local pH. In this work we investigate a physics-based model of ion transport within the mucosal layer based on a Nernst-Planck-like equation. Analysis of this model shows that the mechanism of transporting protons bound to the mucus gel is capable of reproducing the trans-mucus pH gradients reported in the literature. Furthermore, when coupled with ion exchange at the epithelial surface, our analysis shows that bicarbonate secretion alone is capable of neutralizing the epithelial pH, even in the face of enormous diffusive gradients of hydrogen. Maintenance of the pH gradient is found to be robust to a wide array of perturbations in both physiological and phenomenological model parameters, suggesting a robust physiological control mechanism.NEW & NOTEWORTHY This work combines modeling techniques based on physical principles, as well as novel numerical simulations to test the plausibility of one hypothesized mechanism for proton transport across the gastric mucus layer. Results show that this mechanism is able to maintain the extreme pH gradient seen in in vivo experiments and suggests a highly robust regulation mechanism to maintain this gradient in the face of dynamic lumen composition.

Na+ /H+ exchanger NHE1 and NHE2 have opposite effects on migration velocity in rat gastric surface cells.

Following superficial injury, neighbouring gastric epithelial cells close the wound by rapid cell migration, a process called epithelial restitution. Na+/H+ exchange (NHE) inhibitors interfere with restitution, but the role of the different NHE isoforms expressed in gastric pit cells has remained elusive. The role of the basolaterally expressed NHE1 (Slc9a1) and the presumably apically expressed NHE2 (Slc9a2) in epithelial restitution was investigated in the nontransformed rat gastric surface cell line RGM1. Migration velocity was assessed by loading the cells with the fluorescent dye DiR and following closure of an experimental wound over time. Since RGM1 cells expressed very low NHE2 mRNA and have low transport activity, NHE2 was introduced by lentiviral gene transfer. In medium with pH 7.4, RGM1 cells displayed slow wound healing even in the absence of growth factors and independently of NHE activity. Growth factors accelerated wound healing in a partly NHE1‐dependent fashion. Preincubation with acidic pH 7.1 stimulated restitution in a NHE1‐dependent fashion. When pH 7.1 was maintained during the restitution period, migratory speed was reduced to ∼10% of the speed at pH 7,4, and the residual restitution was further inhibited by NHE1 inhibition. Lentiviral NHE2 expression increased the steady‐state pHi and reduced the restitution velocity after low pH preincubation, which was reversible by pharmacological NHE2 inhibition. The results demonstrate that in RGM1 cells, migratory velocity is increased by NHE1 activation, while NHE2 activity inhibit this process. A differential activation of NHE1 and NHE2 may therefore, play a role in the initiation and completion of the epithelial restitution process.

Use of volumetric laser endomicroscopy for dysplasia detection at the gastroesophageal junction and gastric cardia.

AIMTo determine specific volumetric laser endomicroscopy (VLE) imaging features associated with neoplasia at the gastroesophageal junction (GEJ) and gastric cardia.METHODSDuring esophagogastroduodenoscopy for patients with known or suspected Barrett’s esophagus, VLE was performed before biopsies were taken at endoscopists’ discretion. The gastric cardia was examined on VLE scan from the GEJ (marked by top of gastric folds) to 1 cm distal from the GEJ. The NinePoints VLE console was used to analyze scan segments for characteristics previously found to correlate with normal or abnormal mucosa. Glands were counted individually. Imaging features identified on VLE scan were correlated with biopsy results from the GEJ and cardia region.RESULTSThis study included 34 cases. Features characteristic of the gastric cardia (gastric rugae, gastric pit architecture, poor penetration) were observed in all (100%) scans. Loss of classic gastric pit architecture was common and there was no difference between those with neoplasia and without (100% vs 74%, P = NS). The abnormal VLE feature of irregular surface was more often seen in patients with neoplasia than those without (100% vs 18%, P < 0.0001), as was heterogeneous scattering (86% vs 41%, P < 0.005) and presence of anomalous glands (100% vs 59%, P < 0.05). The number of anomalous glands did not differ between individual histologic subgroups (ANOVA, P = NS).CONCLUSIONThe transition from esophagus to gastric cardia is reliably identified on VLE. Histologically abnormal cardia mucosa produces abnormal VLE features. Optical coherence tomography algorithms can be expanded for use at the GEJ/cardia.