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Animal Health Research Reviews Dec 2016Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include... (Review)
Review
Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include encephalitis and gross dilatation of the anterior stomach - the proventriculus. The disease is thus known as proventricular dilatation disease (PDD). PDD is characterized by extreme proventricular dilatation, blockage of the passage of digesta and consequent death by starvation. There are few clinical resemblances between this and the bornaviral encephalitides observed in mammals. Nevertheless, there are common virus-induced pathogenic pathways shared across this disease spectrum that are explored in this review. Additionally, a review of the literature relating to gastroparesis in humans and the control of gastric mobility in mammals and birds points to several plausible mechanisms by which bornaviral infection may result in extreme proventricular dilatation.
Topics: Animals; Bird Diseases; Birds; Bornaviridae; Dilatation; Mononegavirales Infections; Proventriculus
PubMed: 28155804
DOI: 10.1017/S1466252316000189 -
Presse Medicale (Paris, France : 1983) Jan 2018The pathophysiology of achalasia is largely unknown, and involves the destruction of ganglion cell in the esophageal myenteric plexus. High-resolution esophageal... (Review)
Review
The pathophysiology of achalasia is largely unknown, and involves the destruction of ganglion cell in the esophageal myenteric plexus. High-resolution esophageal manometry is the key investigation. Endoscopic pneumodilatation and laparoscopic Heller myotomy have comparable short-term success rates, around 90%. The main complication after pneumodilatation is esophageal perforation, occurring in about 1% of cases. Peroral endoscopic myotomy is a promising treatment modality, however with frequent post-procedural gastroesophageal reflux.
Topics: Botulinum Toxins, Type A; Calcium Channel Blockers; Diagnosis, Differential; Dilatation; Esophageal Achalasia; Esophageal Perforation; Esophagoscopy; Heller Myotomy; Humans; Manometry; Myenteric Plexus; Postoperative Complications; Sphincterotomy
PubMed: 28919276
DOI: 10.1016/j.lpm.2017.08.010 -
Expert Review of Gastroenterology &... Apr 2018Achalasia is a rare esophageal motility disorder. Much of the literature is based on the adult population. In adults, guidance of therapeutic approach by manometric... (Review)
Review
Achalasia is a rare esophageal motility disorder. Much of the literature is based on the adult population. In adults, guidance of therapeutic approach by manometric findings has led to improvement in patient outcome. Promising results have been achieved with novel therapies such as PerOral Endoscopic Myotomy (POEM). Areas covered: In this review, we provide an overview of the novel diagnostic and therapeutic tools for achalasia management and in what way they will relate to the future management of pediatric achalasia. We performed a PubMed and EMBASE search of English literature on achalasia using the keywords 'children', 'achalasia', 'pneumatic dilation', 'myotomy' and 'POEM'. Cohort studies < 10 cases and studies describing patients ≥ 20 years were excluded. Data regarding patient characteristics, treatment outcome and adverse events were extracted and presented descriptively, or pooled when possible. Expert commentary: Available data report that pneumatic dilation and laparoscopic Heller's myotomy are effective in children, with certain studies suggesting lower success rates in pneumatic dilation. POEM is increasingly used in the pediatric setting with promising short-term results. Gastro-esophageal reflux disease (GERD) may occur post-achalasia intervention due to disruption of the LES and therefore requires diligent follow-up, especially in children treated with POEM.
Topics: Adolescent; Age of Onset; Algorithms; Child; Decision Support Techniques; Decision Trees; Deglutition; Dilatation; Esophageal Achalasia; Esophagus; Gastrointestinal Transit; Heller Myotomy; Humans; Laparoscopy; Manometry; Myenteric Plexus; Predictive Value of Tests; Risk Factors; Sclerotherapy; Stents; Treatment Outcome; Young Adult
PubMed: 29439587
DOI: 10.1080/17474124.2018.1441023 -
Current Opinion in Gastroenterology Sep 2018Accurate diagnosis of gastrointestinal neuromuscular diseases requires full thickness biopsy for adequate histologic evaluation of the enteric neuromuscular and... (Review)
Review
PURPOSE OF REVIEW
Accurate diagnosis of gastrointestinal neuromuscular diseases requires full thickness biopsy for adequate histologic evaluation of the enteric neuromuscular and ancillary cells. Historically, this has been achieved by surgical approaches. An overview of procedure evolution and current techniques of endoscopic full thickness biopsy (EFTB) for diagnosis of gastrointestinal neuromuscular disorders will be presented.
RECENT FINDINGS
Emergence and advancement of endoscopic full thickness resection techniques has offered a less invasive, nevertheless an effective modality of tissue acquirement. Recently, clip-assisted close-then-cut EFTB has been utilized in clinical practice under research protocol. Early experience has shown that this technique provides an adequate full-thickness specimen including the myenteric plexus and ganglia cells, with acceptable safety profiles.
SUMMARY
EFTB is a promising means in diagnosing the nature of the disease and guiding therapy. Available animal and human studies have shown the noninferiority of endoscopic methods to surgical ones in term of adequacy of tissue samples, while potentially decreasing the risk and occurrence of complications. Further large prospective studies are needed to assess its efficacy, safety and impacts on patient's outcomes.
Topics: Biopsy; Endoscopy, Gastrointestinal; Gastrointestinal Diseases; Humans; Intestines; Myenteric Plexus; Neuromuscular Diseases
PubMed: 30067562
DOI: 10.1097/MOG.0000000000000464 -
The Journal of Histochemistry and... Jun 2023Gastrointestinal symptoms are common health problems found during aging and neurodegenerative diseases. Trimethyltin-induced rat is known as an animal model of...
Gastrointestinal symptoms are common health problems found during aging and neurodegenerative diseases. Trimethyltin-induced rat is known as an animal model of hippocampal degeneration with no data on enteric neurodegeneration. This study aimed to investigate the effect of trimethyltin (TMT) induction on the gastrointestinal tract. A 28-day animal study with male Sprague-Dawley rats (3 months old, 150-200 g) given a single TMT injection (8 mg/kg body weight, intraperitoneal) was conducted. The number of neurons in the colonic myenteric plexus was measured using stereological estimation. Histological scoring of colon inflammation, immunohistochemistry of tumor necrosis factor-α (TNF-α), and quantitative PCR were conducted. This study showed neuronal loss in the colonic myenteric plexus of TMT-induced rat model of neurodegeneration. Minor colon inflammation characterized by inflammatory cell infiltration and slightly higher expression of TNF-α in the colon mucosa were observed in the TMT-induced rat. However, the gut microbiota composition of the TMT-induced rat was not different from that of the control rats. This study demonstrates that TMT induces colonic myenteric plexus neurodegeneration and minor colon inflammation, which suggests the potential of this animal model to elucidate the communication between the gastrointestinal tract and central nervous system in neurodegenerative diseases.
Topics: Rats; Male; Animals; Myenteric Plexus; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Colon; Inflammation
PubMed: 37322890
DOI: 10.1369/00221554231182195 -
Neurogastroenterology and Motility Jan 2016Achalasia is defined by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) due to deranged inhibitory control. In... (Review)
Review
Achalasia is defined by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) due to deranged inhibitory control. In genetically predisposed individuals, an autoimmune response to an unknown inciting agent, perhaps a viral infection, results in inflammation and sometimes loss of myenteric plexus ganglia and neurons. The net result is varying degrees of inhibitory dysfunction, at times associated with imbalanced and exaggerated excitatory function, with manometrically distinct achalasia phenotypes on high resolution manometry. There is new evidence in the current issue of this Journal suggesting that type 1 achalasia, with esophageal outflow obstruction and absent esophageal body contractility, is an end-stage phenotype from progression of type 2 achalasia, which is characterized by panesophageal compartmentalization of pressure in the untreated patient, and partial recovery of peristalsis after treatment. Esophageal outflow obstruction with premature peristalsis (type 3 achalasia) or intact peristalsis may result from plexitis in the myenteric plexus but can also be encountered in other settings including chronic opioid medication usage and structural processes at the esophagogastric junction and distally. In most instances when idiopathic esophageal outflow obstruction is confirmed, some form of pharmacologic manipulation or disruption of the LES provides durable symptom relief. This review will focus on current understanding of pathophysiology, diagnosis, and principles of management of achalasia in light of emerging literature on the topic.
Topics: Disease Progression; Esophageal Achalasia; Esophageal Motility Disorders; Esophageal Sphincter, Lower; Esophagoscopy; Esophagus; Humans; Manometry; Muscle, Smooth; Myenteric Plexus; Parasympatholytics; Peristalsis; Phenotype; Radiography
PubMed: 26690870
DOI: 10.1111/nmo.12750 -
World Journal of Gastroenterology Aug 2022The enteric nervous system (ENS) is situated along the entire gastrointestinal tract and is divided into myenteric and submucosal plexuses in the small and large...
BACKGROUND
The enteric nervous system (ENS) is situated along the entire gastrointestinal tract and is divided into myenteric and submucosal plexuses in the small and large intestines. The ENS consists of neurons, glial cells, and nerves assembled into ganglia, surrounded by telocytes, interstitial cells of Cajal, and connective tissue. Owing to the complex spatial organization of several interconnections with nerve fascicles, the ENS is difficult to examine in conventional histological sections of 3-5 μm.
AIM
To examine human ileum full-thickness biopsies using X-ray phase-contrast nanotomography without prior staining to visualize the ENS.
METHODS
Six patients were diagnosed with gastrointestinal dysmotility and neuropathy based on routine clinical and histopathological examinations. As controls, full-thickness biopsies were collected from healthy resection ileal regions after hemicolectomy for right colon malignancy. From the paraffin blocks, 4-µm thick sections were prepared and stained with hematoxylin and eosin for localization of the myenteric ganglia under a light microscope. A 1-mm punch biopsy (up to 1 cm in length) centered on the myenteric plexus was taken and placed into a Kapton tube for mounting in the subsequent investigation. X-ray phase-contrast tomography was performed using two custom-designed laboratory setups with micrometer resolution for overview scanning. Subsequently, selected regions of interest were scanned at a synchrotron-based end-station, and high-resolution slices were reported. In total, more than 6000 virtual slices were analyzed from nine samples.
RESULTS
In the overview scans, the general architecture and quality of the samples were studied, and the myenteric plexus was localized. High-resolution scans revealed details, including the ganglia, interganglional nerve fascicles, and surrounding tissue. The ganglia were irregular in shape and contained neurons and glial cells. Spindle-shaped cells with very thin cellular projections could be observed on the surface of the ganglia, which appeared to build a network. In the patients, there were no alterations in the general architecture of the myenteric ganglia. Nevertheless, several pathological changes were observed, including vacuolar degeneration, autophagic activity, the appearance of sequestosomes, chromatolysis, and apoptosis. Furthermore, possible expulsion of pyknotic neurons and defects in the covering cellular network could be observed in serial slices. These changes partly corresponded to previous light microscopy findings.
CONCLUSION
The analysis of serial virtual slices could provide new information that cannot be obtained by classical light microscopy. The advantages, disadvantages, and future possibilities of this method are also discussed.
Topics: Enteric Nervous System; Eosine Yellowish-(YS); Hematoxylin; Humans; Ileum; Myenteric Plexus; Paraffin; X-Rays
PubMed: 36157532
DOI: 10.3748/wjg.v28.i29.3994 -
Journal of Neuroscience Methods Jun 2023Neuropeptides are a highly diverse group of signaling molecules found in the central nervous system (CNS) and peripheral organs, including the enteric nervous system... (Review)
Review
Neuropeptides are a highly diverse group of signaling molecules found in the central nervous system (CNS) and peripheral organs, including the enteric nervous system (ENS). Increasing efforts have been focused on dissecting the role of neuropeptides in both neural- and non-neural-related diseases, as well as their potential therapeutic value. In parallel, accurate knowledge on their source of production and pleiotropic functions is still needed to fully understand their implications in biological processes. This review will focus on the analytical challenges involved in studying neuropeptides, particularly in the ENS, a tissue where their abundance is low, together with opportunities for further technical development.
Topics: Enteric Nervous System; Neuropeptides; Signal Transduction; Central Nervous System; Myenteric Plexus
PubMed: 37172914
DOI: 10.1016/j.jneumeth.2023.109882 -
Therapeutic Advances in... 2021Achalasia is a primary esophageal motility disorder characterized by the loss of inhibitory neurons in the myenteric plexus, resulting in impaired relaxation of the... (Review)
Review
Achalasia is a primary esophageal motility disorder characterized by the loss of inhibitory neurons in the myenteric plexus, resulting in impaired relaxation of the esophagogastric junction. Achalasia is an incurable disease, and the treatment modalities are aimed at disruption of the esophagogastric junction and vary widely from pharmacological to endoscopic to surgical. Traditional endoscopic therapy includes pneumatic dilation, botulinum toxin injection, and peroral endoscopic myotomy. This review aims to provide an overview of the endoscopic management of achalasia, while focusing on the utilization of peroral endoscopic myotomy and other novel approaches.
PubMed: 34017943
DOI: 10.1177/26317745211014706 -
Cellular and Molecular Gastroenterology... 2021Neuroinflammation in the gut is associated with many gastrointestinal (GI) diseases, including inflammatory bowel disease. In the brain, neuroinflammatory conditions are...
BACKGROUND & AIMS
Neuroinflammation in the gut is associated with many gastrointestinal (GI) diseases, including inflammatory bowel disease. In the brain, neuroinflammatory conditions are associated with blood-brain barrier (BBB) disruption and subsequent neuronal injury. We sought to determine whether the enteric nervous system is similarly protected by a physical barrier and whether that barrier is disrupted in colitis.
METHODS
Confocal and electron microscopy were used to characterize myenteric plexus structure, and FITC-dextran assays were used to assess for presence of a barrier. Colitis was induced with dextran sulfate sodium, with co-administration of liposome-encapsulated clodronate to deplete macrophages.
RESULTS
We identified a blood-myenteric barrier (BMB) consisting of extracellular matrix proteins (agrin and collagen-4) and glial end-feet, reminiscent of the BBB, surrounded by a collagen-rich periganglionic space. The BMB is impermeable to the passive movement of 4 kDa FITC-dextran particles. A population of macrophages is present within enteric ganglia (intraganglionic macrophages [IGMs]) and exhibits a distinct morphology from muscularis macrophages, with extensive cytoplasmic vacuolization and mitochondrial swelling but without signs of apoptosis. IGMs can penetrate the BMB in physiological conditions and establish direct contact with neurons and glia. Dextran sulfate sodium-induced colitis leads to BMB disruption, loss of its barrier integrity, and increased numbers of IGMs in a macrophage-dependent process.
CONCLUSIONS
In intestinal inflammation, macrophage-mediated degradation of the BMB disrupts its physiological barrier function, eliminates the separation of the intra- and extra-ganglionic compartments, and allows inflammatory stimuli to access the myenteric plexus. This suggests a potential mechanism for the onset of neuroinflammation in colitis and other GI pathologies with acquired enteric neuronal dysfunction.
Topics: Animals; Biomarkers; Colitis; Disease Models, Animal; Disease Susceptibility; Enteric Nervous System; Extracellular Matrix; Fluorescent Antibody Technique; Immunohistochemistry; Immunophenotyping; Macrophages; Mice; Myenteric Plexus; Neuroglia; Neuroinflammatory Diseases; Neutrophil Infiltration
PubMed: 34246810
DOI: 10.1016/j.jcmgh.2021.07.003