5,473 results match your criteria American Journal Of Physiology-Gastrointestinal And Liver Physiology[Journal]


Postprandial Symptoms in Patients with Symptoms of Gastroparesis: Roles of Gastric Emptying and Accommodation.

Am J Physiol Gastrointest Liver Physiol 2022 May 3. Epub 2022 May 3.

Texas Tech University Health Sciences Center, El Paso, TX, United States.

Introduction: Patients often are evaluated for gastroparesis (Gp) due to symptoms occurring with meals. Gastric emptying scintigraphy (GES) is used for Gp diagnosis, although results are not well correlated with Gp symptoms.

Aim: To assess the relationships between Gp symptoms, gastric emptying (GE) and gastric accommodation (GA). Read More

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Mechanisms underlying initiation of propulsion in guinea pig distal colon.

Am J Physiol Gastrointest Liver Physiol 2022 May 3. Epub 2022 May 3.

College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.

Colonic motor complexes (CMCs) are a major neurogenic activity in guinea-pig distal colon. The identity of the enteric neurons that initiate this activity is not established. Specialized intrinsic primary afferent neurons (IPANs) are a major candidate. Read More

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Differential mRNA Expression in Ileal and Colonic Biopsies in Irritable Bowel Syndrome with Diarrhea or Constipation.

Am J Physiol Gastrointest Liver Physiol 2022 May 3. Epub 2022 May 3.

Clinical Enteric Neuroscience Translational and Epidemiology Research (C.E.N.T.E.R.), Mayo Clinic, Rochester, MN, United States.

Background & Aims: Altered mucosal functions are documented in jejunal or colorectal mucosa from patients with IBS.

Aim: To quantify ileal, ascending and rectosigmoid colon mucosal expression of genes in IBS-diarrhea (D) and IBS-constipation (C).

Methods: 44 patients with IBS-D, 30 with IBS-C, and 30 healthy volunteers underwent colonoscopic ileal, ascending and rectosigmoid colon biopsies. Read More

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Intrathecally administered substance P activated the spinal defecation center and enhanced colorectal motility in anesthetized rats.

Am J Physiol Gastrointest Liver Physiol 2022 Apr 26. Epub 2022 Apr 26.

Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.

Noxious stimuli on the colorectum cause colorectal contractions through activation of descending monoaminergic pathways projecting from the supraspinal defecation center to the spinal defecation center. Since it is known that substance P is involved in the response to peripheral noxious stimuli in the spinal cord, we investigated the effects of intrathecally administered substance P at L6-S1 levels on colorectal motility in rats that were anesthetized with alpha-chloralose and ketamine. Intrathecally administered substance P enhanced colorectal motility, even after transection of the thoracic spinal cord at the T4 level. Read More

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Contribution of sex hormones to the sexually dimorphic response of colorectal motility to noxious stimuli in rats.

Am J Physiol Gastrointest Liver Physiol 2022 Apr 19. Epub 2022 Apr 19.

Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.

Our recent studies have shown that noxious stimuli in the colorectum enhance colorectal motility via the brain and spinal defecation centers in male rats. In female rats, on the other hand, noxious stimuli have no effect on colorectal motility. The purpose of this study was to determine whether sex hormones are major contributing factors for sex-dependent differences in neural components of the spinal defecation center. Read More

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Molecules involved in the development of Barrett's esophagus (BE) phenotype in chronic eosinophilic esophagitis (EoE).

Am J Physiol Gastrointest Liver Physiol 2022 Apr 19. Epub 2022 Apr 19.

John W. Deming Department of Medicine, Section of Pulmonary Diseases, Tulane Eosinophilic Disorder Center (TEDC), Tulane University School of Medicine, New Orleans, LA, United States.

Objectives: Investigate the molecules involved in development of Barrett's esophagus (BE) in human EoE.

Methods: Histopathological, immunohistochemical, real-time PCR and ELISA analyses are performed to identify the signature genes and proteins involved in the progression of BE in EoE.

Results: We detected characteristic feature of BE like intermediate columnar type epithelial cells, induced BE signature genes like ErbB3, CDX1, ErbB2IP in the esophageal mucosa of EoE patients. Read More

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A human Barrett's esophagus organoid system reveals epithelial-mesenchymal plasticity induced by acid and bile salts.

Am J Physiol Gastrointest Liver Physiol 2022 Jun 5;322(6):G598-G614. Epub 2022 Apr 5.

Division of Gastroenterology, Department of Medicine, Baylor University Medical Center, Dallas, Texas.

The pathogenesis of subsquamous intestinal metaplasia (SSIM), in which glands of Barrett's esophagus (BE) are buried under esophageal squamous epithelium, is unknown. In a rat model of reflux esophagitis, we found that columnar-lined esophagus developed via a wound-healing process involving epithelial-mesenchymal plasticity (EMP) that buried glands under ulcerated squamous epithelium. To explore a role for reflux-induced EMP in BE, we established and characterized human Barrett's organoids and sought evidence of EMP after treatment with acidic bile salts (AB). Read More

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Impaired nitrergic relaxation in pyloric sphincter of the 6-OHDA Parkinson's disease rat.

Am J Physiol Gastrointest Liver Physiol 2022 Jun 5;322(6):G553-G560. Epub 2022 Apr 5.

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China.

Patients with Parkinson's disease (PD) often suffer from delayed gastric emptying, but the underlying mechanism remains unclear. We have shown previously that a PD rat model comprising bilateral substantia nigra destruction by 6-hydroxydopamine (6-OHDA rats) exhibits gastroparesis with alteration of neural nitric oxide synthase (nNOS) and acetylcholine in gastric corpus. However, changes in pyloric motility in the 6-OHDA rats have not been characterized. Read More

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Early-life fecal microbiome and metabolome dynamics in response to an intervention with infant formula containing specific prebiotics and postbiotics.

Am J Physiol Gastrointest Liver Physiol 2022 Jun 29;322(6):G571-G582. Epub 2022 Mar 29.

Pediatrics Department, Reina Sofia University Hospital, Maimonides Institute for Biomedical Research, CIBERER, Cordoba, Spain.

This study examined fecal metabolome dynamics to gain greater functional insights into the interactions between nutrition and the activity of the developing gut microbiota in healthy term-born infants. The fecal samples used here originate from a randomized, controlled, double-blind clinical study that assessed the efficacy of infant formula with prebiotics and postbiotics (experimental arm) compared with a standard infant formula (control arm). A group of exclusively breast-fed term infants was used as a reference arm. Read More

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Adult enteric Dclk1-positive glial and neuronal cells reveal distinct responses to acute intestinal injury.

Am J Physiol Gastrointest Liver Physiol 2022 Jun 23;322(6):G583-G597. Epub 2022 Mar 23.

Division of Digestive and Liver Diseases, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York.

Intestinal ganglionic cells in the adult enteric nervous system (ENS) are continually exposed to stimuli from the surrounding microenvironment and need at times to respond to disturbed homeostasis following acute intestinal injury. The kinase DCLK1 and intestinal Dclk1-positive cells have been reported to contribute to intestinal regeneration. Although Dclk1-positive cells are present in adult enteric ganglia, their cellular identity and response to acute injury have not been investigated in detail. Read More

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Corrigendum for Liu et al., volume 305, 2013, p. G163-G171.

Authors:

Am J Physiol Gastrointest Liver Physiol 2022 Apr;322(4):G457-G458

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Initiation and severity of experimental pancreatitis are modified by phosphate.

Am J Physiol Gastrointest Liver Physiol 2022 Jun 16;322(6):G561-G570. Epub 2022 Mar 16.

Department of Medicine, Duke University, Durham, North Carolina.

Proper mitochondrial function and adequate cellular ATP are necessary for normal pancreatic protein synthesis and sorting, maintenance of intracellular organelles and enzyme secretion. Inorganic phosphate is required for generating ATP and its limited availability may lead to reduced ATP production causing impaired Ca handling, defective autophagy, zymogen activation, and necrosis, which are all features of acute pancreatitis. We hypothesized that reduced dietary phosphate leads to hypophosphatemia and exacerbates pancreatitis severity of multiple causes. Read More

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The gut-brain axis: spatial relationship between spinal afferent nerves and 5-HT-containing enterochromaffin cells in mucosa of mouse colon.

Am J Physiol Gastrointest Liver Physiol 2022 May 16;322(5):G523-G533. Epub 2022 Mar 16.

Visceral Neurophysiology Laboratory, Flinders Health and Medical Research Institute & College of Medicine and Public Health, Flinders University of South Australia, Bedford Park, South Australia, Australia.

Cross talk between the gastrointestinal tract and brain is of significant relevance for human health and disease. However, our understanding of how the gut and brain communicate has been limited by a lack of techniques to identify the precise spatial relationship between extrinsic nerve endings and their proximity to specific cell types that line the inner surface of the gastrointestinal tract. We used an in vivo anterograde tracing technique, previously developed in our laboratory, to selectively label single spinal afferent axons and their nerve endings in mouse colonic mucosa. Read More

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Microbial metabolites: cause or consequence in gastrointestinal disease?

Am J Physiol Gastrointest Liver Physiol 2022 Jun 10;322(6):G535-G552. Epub 2022 Mar 10.

Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas.

Systems biology studies have established that changes in gastrointestinal microbiome composition and function can adversely impact host physiology. Notable diseases synonymously associated with dysbiosis include inflammatory bowel diseases, cancer, metabolic disorders, and opportunistic and recurrent pathogen infections. However, there is a scarcity of mechanistic data that advances our understanding of taxonomic correlations with pathophysiological host-microbiome interactions. Read More

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Bile acid detergency: permeability, inflammation, and effects of sulfation.

Am J Physiol Gastrointest Liver Physiol 2022 May 8;322(5):G480-G488. Epub 2022 Mar 8.

Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.

Bile acids are amphipathic, detergent molecules. The detergent effects of di-α-hydroxy-bile acids are relevant to several colonic diseases. The aims were to review the concentrations of bile acids reaching the human colon in health and disease, the molecular structure of bile acids that determine detergent functions and the relationship to human diseases (neuroendocrine tumors, microscopic colitis, active celiac disease, and ulcerative colitis, Crohn's disease and ileal resection), the relationship to bacterial uptake into the mucosa, mucin depletion, and epithelial damage, the role of bile acids in mucosal inflammation and microscopic colitis, and the role of sulfation of bile salts in detoxification or prevention of the detergent effects of bile acids. Read More

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Deacetylation of Notch1 by SIRT1 contributes to HBsAg- and HBeAg-mediated M2 macrophage polarization.

Am J Physiol Gastrointest Liver Physiol 2022 04 2;322(4):G459-G471. Epub 2022 Mar 2.

Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, People's Republic of China.

Hepatic macrophages are involved in both pathogen clearance and immunopathogenesis. Emerging evidence demonstrates that macrophage polarization plays a critical role in hepatitis B virus (HBV)-induced immune impairment and liver pathology. However, it remains largely unknown as to how HBV infection facilitates M2 macrophage polarization. Read More

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Revisiting the gut-liver axis: gut lymphatic system in liver cirrhosis and portal hypertension.

Am J Physiol Gastrointest Liver Physiol 2022 May 23;322(5):G473-G479. Epub 2022 Feb 23.

Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, New Delhi, India.

The lymphatic vascular system runs parallel to the blood vascular system, comprising a network of lymphatic vessels and secondary lymphoid organs. The intestinal lymphatic capillaries (lacteals) and the associated collecting vessels in the mesentery form the gut lymphatic system. The gut lymphatic vasculature comprises the longest-studied lymphatic vessel bed and plays a significant role in the uptake and transport of dietary fat, abdominal fluid balance, and gut immunosurveillance. Read More

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Exaggerated inflammatory response to bacterial products in decompensated cirrhotic patients is orchestrated by interferons IL-6 and IL-8.

Am J Physiol Gastrointest Liver Physiol 2022 May 23;322(5):G489-G499. Epub 2022 Feb 23.

Institute of Liver Studies, Department of Inflammation Biology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom.

Cirrhosis-associated immune dysfunction (CAID) contributes to disease progression and organ failure development. We interrogated immune system function in nonseptic compensated and decompensated cirrhotic patients using the TruCulture whole blood stimulation system, a novel technique that allows a more accurate representation than traditional methods, such as peripheral blood mononuclear cell culture, of the immune response in vivo. Thirty cirrhotics (21 decompensated and 9 compensated) and seven healthy controls (HCs) were recruited. Read More

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Myotomy technique and esophageal contractility impact blown-out myotomy formation in achalasia: an in silico investigation.

Am J Physiol Gastrointest Liver Physiol 2022 May 16;322(5):G500-G512. Epub 2022 Feb 16.

Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, Illinois.

We used in silico models to investigate the impact of the dimensions of myotomy, contraction pattern, the tone of the esophagogastric junction (EGJ), and musculature at the myotomy site on esophageal wall stresses potentially leading to the formation of a blown-out myotomy (BOM). We performed three sets of simulations with an in silico esophagus model, wherein the myotomy-influenced region was modeled as an elliptical section devoid of muscle fibers. These sets investigated the effects of the dimensions of myotomy, differing esophageal contraction types, and differing esophagogastric junction (EGJ) tone and wall stiffness at the myotomy affected region on esophageal wall stresses potentially leading to BOM. Read More

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Intestinal secretory mechanisms and diarrhea.

Am J Physiol Gastrointest Liver Physiol 2022 04 16;322(4):G405-G420. Epub 2022 Feb 16.

Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California.

One of the primary functions of the intestinal epithelium is to transport fluid and electrolytes to and from the luminal contents. Under normal circumstances, absorptive and secretory processes are tightly regulated such that absorption predominates, thereby enabling conservation of the large volumes of water that pass through the intestine each day. However, in conditions of secretory diarrhea, this balance becomes dysregulated, so that fluid secretion, driven primarily by Cl secretion, overwhelms absorptive capacity, leading to increased loss of water in the stool. Read More

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Stress-induced neuroplasticity in the gastric response to brainstem oxytocin in male rats.

Am J Physiol Gastrointest Liver Physiol 2022 May 16;322(5):G513-G522. Epub 2022 Feb 16.

Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania.

Previous studies have shown that pharmacological manipulations with stress-related hormones such as corticotropin-releasing factor and thyrotropin-releasing hormone induce neuroplasticity in brainstem vagal neurocircuits, which modulate gastric tone and motility. The prototypical antistress hormone oxytocin (OXT) has been shown to modulate gastric tone and motility via vagal pathways, and descending hypothalamic oxytocinergic inputs play a major role in the vagally dependent gastric-related adaptations to stress. The aim of this study was to investigate the possible cellular mechanisms through which OXT modulates central vagal brainstem and peripheral enteric neurocircuits of male Sprague-Dawley rats in response to chronic repetitive stress. Read More

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Angiotensin receptor blocker alleviates liver fibrosis by altering the mechanotransduction properties of hepatic stellate cells.

Am J Physiol Gastrointest Liver Physiol 2022 04 9;322(4):G446-G456. Epub 2022 Feb 9.

Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan.

Angiotensin receptor blockers have been reported to be beneficial to liver fibrosis, but the relevant molecular and cellular mechanisms remain unclear. We herein investigated whether low-dose angiotensin receptor blocker alleviated liver fibrosis through mechanotransduction regulation. Hydrostatic pressure-induced liver fibrosis model was established in mice by ligating partially the inferior vena cava, and then randomly received a very low dose of losartan (0. Read More

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Evaluation of oropharyngeal deglutitive pressure dynamics in patients with Parkinson's disease.

Am J Physiol Gastrointest Liver Physiol 2022 04 9;322(4):G421-G430. Epub 2022 Feb 9.

St George and Sutherland Clinical School, University of NSW, Sydney, Australia.

In Parkinson's disease (PD), oropharyngeal dysphagia is common and clinically relevant. The neurophysiology of dysphagia in PD is complex and incompletely understood. The aim of the study was to determine the changes in oropharyngeal deglutitive pressure dynamics in PD and to correlate these with clinical characteristics including dysphagia and PD severity. Read More

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Targeted ablation of gastric pacemaker sites to modulate patterns of bioelectrical slow wave activation and propagation in an anesthetized pig model.

Am J Physiol Gastrointest Liver Physiol 2022 04 9;322(4):G431-G445. Epub 2022 Feb 9.

Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.

Gastric motility is coordinated by underlying bioelectrical slow waves. Gastric dysrhythmias occur in gastrointestinal (GI) motility disorders, but there are no validated methods for eliminating dysrhythmias. We hypothesized that targeted ablation could eliminate pacemaker sites in the stomach, including dysrhythmic ectopic pacemaker sites. Read More

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The therapeutic potential of exosomes derived from different cell sources in liver diseases.

Am J Physiol Gastrointest Liver Physiol 2022 04 2;322(4):G397-G404. Epub 2022 Feb 2.

Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.

Exosomes are small nanovesicles with a size of approximately 40-120 nm that are secreted from cells. They are involved in the regulation of cell homeostasis and mediate intercellular communication. In addition, they carry proteins, nucleic acids, and lipids that regulate the biological activity of receptor cells. Read More

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Nrf2 attenuates hyperglycemia-induced nNOS impairment in adult mouse primary enteric neuronal crest cells and normalizes stomach function.

Am J Physiol Gastrointest Liver Physiol 2022 03 27;322(3):G368-G382. Epub 2022 Jan 27.

Department of ODS and Research, School of Dentistry, Meharry Medical College, Nashville, Tennessee.

Enteric neuronal cells play a vital role in gut motility in humans and experimental rodent models. Patients with diabetes are more vulnerable to gastrointestinal dysfunction due to enteric neuronal degeneration. In this study, we examined the mechanistic role and regulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) in hyperglycemia-induced enteric neuronal cell apoptosis in vitro by using adult mouse primary enteric neuronal crest cells (pENCs). Read More

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Emodin reduces tumor burden by diminishing M2-like macrophages in colorectal cancer.

Am J Physiol Gastrointest Liver Physiol 2022 03 12;322(3):G383-G395. Epub 2022 Jan 12.

Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina.

Emodin, a natural anthraquinone, has been shown to have antitumorigenic properties and may be an effective therapy for colorectal cancer (CRC). However, its clinical development has been hampered by a poor understanding of its mechanism of action. The purpose of this study was to ) evaluate the efficacy of emodin in mouse models of intestinal/colorectal cancer and ) to examine the impact of emodin on macrophage behavior in the context of CRC. Read More

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MAPK p38/Ulk1 pathway inhibits autophagy and induces IL-1β expression in hepatic stellate cells.

Am J Physiol Gastrointest Liver Physiol 2022 03 12;322(3):G360-G367. Epub 2022 Jan 12.

Institution of Hepatology, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, China.

In the past, hepatic stellate cells (HSCs) were considered to be noninflammatory cells and to contribute to liver fibrosis by producing extracellular matrix. Recently, it was found that HSCs can also secrete cytokines and chemokines and therefore participate in hepatic inflammation. Autophagy participates in many immune response processes in immune cells. Read More

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Exposure to binge ethanol and fatty acid ethyl esters exacerbates chronic ethanol-induced pancreatic injury in hepatic alcohol dehydrogenase-deficient deer mice.

Am J Physiol Gastrointest Liver Physiol 2022 03 5;322(3):G327-G345. Epub 2022 Jan 5.

Department of Pathology, The University of Texas Medical Branch, Galveston, Texas.

Alcoholic chronic pancreatitis (ACP) is a fibroinflammatory disease of the pancreas. However, metabolic basis of ACP is not clearly understood. In this study, we evaluated differential pancreatic injury in hepatic alcohol dehydrogenase-deficient (ADH) deer mice fed chronic ethanol (EtOH), chronic plus binge EtOH, and chronic plus binge EtOH and fatty acid ethyl esters (FAEEs, nonoxidative metabolites of EtOH) to understand the metabolic basis of ACP. Read More

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