36 results on '"Michael Schemann"'
Search Results
2. Targeting nNOS ameliorates the severe neuropathic pain due to chronic pancreatitis
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Betül Gökcek, Güralp O. Ceyhan, Mert Erkan, Matthias Maak, Kalliope N. Diakopoulos, Michael Schemann, Helmut Friess, Achim Krüger, Sarah Klauss, Bahar E. Ucurum, Steffen Teller, Ihsan Ekin Demir, Elke Tieftrunk, Dorukhan H. Bahceci, Timo Kehl, Carmen Mota Reyes, Dominique G. Carty, Hana Algül, Ömer Cemil Saricaoglu, Tobias Heinrich, Maria Lazarou, Marina Lesina, Bahçeci, Dorukhan H., Gökçek, Betül, Uçurum, Bahar E., Erkan, Murat Mert (ORCID 0000-0002-2753-0234 & YÖK ID 214689), Demir, İhsan Ekin, Heinrich, Tobias, Carty, Dominique G., Sarıcaoğlu, Ömer Cemil, Klauss, Sarah, Teller, Steffen, Kehl, Timo, Reyes, Carmen Mota, Tieftrunk, Elke, Lazarou, Maria, Maak, Matthias, Diakopoulos, Kalliope N., Lesina, Marina, Schemann, Michael, Krueger, Achim, Algül, Hana, Friess, Helmut, Ceyhan, Güralp O., School of Medicine, Department of General Surgery, and Acibadem University Dspace
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Male ,0301 basic medicine ,Research paper ,Pancreatic disease ,Nitric Oxide Synthase Type I ,Pharmacology ,Mice ,0302 clinical medicine ,Molecular Targeted Therapy ,Nitrergic ,Enzyme Inhibitors ,Genetically engineered mice ,General Medicine ,Middle Aged ,Immunohistochemistry ,ddc ,030220 oncology & carcinogenesis ,Neuropathic pain ,Knockout mouse ,Female ,Atg5 ,Chronic pancreatitis ,Neurology of the digestive tract ,Adult ,Medicine ,General and internal medicine ,Pancreatic Extracts ,Pain ,nNOS ,Mice, Transgenic ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Pancreatitis, Chronic ,Pancreatic cancer ,Genetic model ,medicine ,Animals ,Humans ,business.industry ,Brain-Derived Neurotrophic Factor ,medicine.disease ,Pancreatic Neoplasms ,Disease Models, Animal ,030104 developmental biology ,nervous system ,Research and experimental medicine ,Neuralgia ,Pancreatitis ,business ,Biomarkers ,Ex vivo - Abstract
Background: pain due to pancreatic cancer/PCa or chronic pancreatitis/CP, is notoriously resistant to the strongest pain medications. Here, we aimed at deciphering the specific molecular mediators of pain at surgical-stage pancreatic disease and to discover novel translational targets. Methods: we performed a systematic, quantitative analysis of the neurotransmitter/neuroenzmye profile within intrapancreatic nerves of CP and PCa patients. Ex vivo neuronal cultures treated with human pancreatic extracts, conditional genetically engineered knockout mouse models of PCa and CP, and the cerulein-induced CP model were employed to explore the therapeutic potential of the identified targets. Findings: we identified a unique enrichment of neuronal nitric-oxide-synthase (nNOS) in the pancreatic nerves of CP patients with increasing pain severity. Employment of ex vivo neuronal cultures treated with pancreatic tissue extracts of CP patients, and brain-derived-neurotrophic-factor-deficient (BDNF+/−) mice revealed neuronal enrichment of nNOS to be a consequence of BDNF loss in the progressively destroyed pancreatic tissue. Mechanistically, nNOS upregulation in sensory neurons was induced by tryptase secreted from perineural mast cells. In a head-to-head comparison of several genetically induced, painless mouse models of PCa (KPC, KC mice) or CP (Ptf1a-Cre;Atg5fl/fl) against the hypersecretion/cerulein-induced, painful CP mouse model, we show that a similar nNOS enrichment is present in the painful cerulein-CP model, but absent in painless genetic models. Consequently, mice afflicted with painful cerulein-induced CP could be significantly relieved upon treatment with the specific nNOS inhibitor NPLA. Interpretation: we propose nNOS inhibition as a novel strategy to treat the unbearable pain in CP. Fund: Deutsche Forschungsgemeinschaft/DFG (DE2428/3-1 and 3-2)., Deutsche Forschungsgemeinschaft (DFG)
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- 2019
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3. Extracts from peppermint leaves, lemon balm leaves and in particular angelica roots mimic the pro-secretory action of the herbal preparation STW 5 in the human intestine
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Florian Zeller, Michael Schemann, G.O. Ceyhan, Ihsan Ekin Demir, Dagmar Krueger, and Shady Allam
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Adult ,Adolescent ,Pharmaceutical Science ,In Vitro Techniques ,Melissa ,Plant Roots ,Cell Line ,Young Adult ,Intestinal mucosa ,Drug Discovery ,Humans ,Medicine ,Secretion ,Intestinal Mucosa ,Aged ,Angelica ,Aged, 80 and over ,Pharmacology ,Traditional medicine ,biology ,Ussing chamber ,Plant Extracts ,business.industry ,Epithelial Cells ,Mentha piperita ,Middle Aged ,Epithelial sodium channel blocker ,Small intestine ,Cystic fibrosis transmembrane conductance regulator ,Amiloride ,Intestines ,Plant Leaves ,medicine.anatomical_structure ,Complementary and alternative medicine ,Chloride channel ,biology.protein ,Molecular Medicine ,business ,medicine.drug - Abstract
Aim The herbal preparation STW 5 contains fresh plant extracts from bitter candytuft whole plant, extracts from greater celandine herb, angelica root, lemon balm leaves, peppermint leaves, caraway fruit, liquorice root, chamomile flower and milk thistle fruit. We recently reported that STW 5 increased intestinal chloride secretion and proposed that this action may be involved in its clinical efficacy in the treatment of irritable bowel syndrome. The aim of this study was to identify the extracts responsible for the secretory action in order to provide the basis to develop novel target oriented herbal combinations. Methods We used the Ussing chamber voltage clamp technique to study the effects of individual extracts of STW 5 on short circuit current (Isc, reflecting electrogenic ion transport across epithelial cells) in mucosal/submucosal preparations of human small or large intestinal specimens and the human epithelial cell line T84. Results STW 5 at concentrations of 512 µg/ml and 5120 µg/ml evoked an increase in Isc. The increase at the lower concentration was due to pro-secretory effects of angelica which were nerve mediated. The increase at the higher concentration was additionally mimicked by peppermint and lemon balm. The remaining extracts did not influence ISC in the large intestine. The results were similar in T84 cells except that angelica had no effect while chamomile induced secretion. These pro-secretory effects were reduced by adenylate cyclase inhibitor MDL-12330A, cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 and calcium activated chloride channels blocker 4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid (SITS). Liquorice decreased ISC only in small intestine which was reversed by the epithelial sodium channel blocker amiloride. Conclusions Results suggested that the pro-secretory action of STW 5 is mainly due to angelica with lesser contribution of peppermint and lemon balm. Their effects involve activation of cAMP- and Ca++-activated Cl− channels. We suggest that peppermint, lemon balm and in particular angelica may be the basis to develop novel herbal preparations to specifically treat secretory disorder based on impaired epithelial secretion, such as constipation.
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- 2015
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4. Enterococcus faecalis Metalloprotease Compromises Epithelial Barrier and Contributes to Intestinal Inflammation
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Mihaela Pruteanu, Dirk Haller, R. Balfor Sartor, Fergus Shanahan, Sandra C. Kim, Roger Vogelmann, Katrin Mair, Michael Schemann, Bernhard Kuster, Dagmar Krueger, Irina Sava, Hannes Hahne, Susan L. Tonkonogy, Micha Hoffmann, and Natalie Steck
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CD4-Positive T-Lymphocytes ,Cell Membrane Permeability ,Inflammation ,Enterococcus faecalis ,Microbiology ,Pathogenesis ,Mice ,Intestinal mucosa ,medicine ,Animals ,Gelatinase ,Intestinal Mucosa ,Colitis ,Gram-Positive Bacterial Infections ,Barrier function ,Mice, Knockout ,Hepatology ,biology ,Tumor Necrosis Factor-alpha ,Gastroenterology ,Cadherins ,biology.organism_classification ,medicine.disease ,Mice, Mutant Strains ,Interleukin-10 ,Disease Models, Animal ,Gelatinases ,Metalloproteases ,Tumor necrosis factor alpha ,medicine.symptom - Abstract
Background & Aims Matrix metalloproteases (MMPs) mediate pathogenesis of chronic intestinal inflammation. We characterized the role of the gelatinase (GelE), a metalloprotease from Enterococcus faecalis , in the development of colitis in mice. Methods Germ-free, interleukin-10–deficient (IL-10 −/− ) mice were monoassociated with the colitogenic E faecalis strain OG1RF and isogenic, GelE-mutant strains. Barrier function was determined by measuring E-cadherin expression, transepithelial electrical resistance (TER), and translocation of permeability markers in colonic epithelial cells and colon segments from IL-10 −/− and TNF ΔARE/Wt mice. GelE specificity was shown with the MMP inhibitor marimastat. Results Histologic analysis (score 0–4) of E faecalis monoassociated IL-10 −/− mice revealed a significant reduction in colonic tissue inflammation in the absence of bacteria-derived GelE. We identified cleavage sites for GelE in the sequence of recombinant mouse E-cadherin, indicating that it might be degraded by GelE. Experiments with Ussing chambers and purified GelE revealed the loss of barrier function and extracellular E-cadherin in mice susceptible to intestinal inflammation (IL-10 −/− and TNF ΔARE/Wt mice) before inflammation developed. Colonic epithelial cells had reduced TER and increased translocation of permeability markers after stimulation with GelE from OG1RF or strains of E faecalis isolated from patients with Crohn's disease and ulcerative colitis. Conclusions The metalloprotease GelE, produced by commensal strains of E faecalis, contributes to development of chronic intestinal inflammation in mice that are susceptible to intestinal inflammation (IL-10 −/− and TNF ΔARE/Wt mice) by impairing epithelial barrier integrity.
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- 2011
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5. Demonstration of Functional Neuronal β3-Adrenoceptors Within the Enteric Nervous System
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Olutunde Lalude, Karen M. Gray, Ramkumar Thangiah, Anna K. Bassil, Selim Cellek, Alan Wheeldon, Gareth J. Sanger, Shanmugam Vivekanandan, Jennifer L. Stretton, Michael Schemann, Colin A. Campbell, Kevin Lee, and Wendy J. Winchester
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Diarrhea ,Agonist ,Castor Oil ,medicine.medical_specialty ,Colon ,medicine.drug_class ,Visceral Afferents ,Myenteric Plexus ,Adrenergic beta-3 Receptor Agonists ,Dioxoles ,Biology ,Internal medicine ,medicine ,Animals ,Humans ,Plant Oils ,Myenteric plexus ,Hepatology ,Cathartics ,Gastroenterology ,Rats, Inbred Strains ,Visceral pain ,Algesia ,Submucous Plexus ,Adrenergic beta-Agonists ,Immunohistochemistry ,Choline acetyltransferase ,Abdominal Pain ,Rats ,Somatostatin ,Endocrinology ,Receptors, Adrenergic, beta-3 ,Cholinergic ,Enteric nervous system ,medicine.symptom ,Gastrointestinal Motility ,Mustard Plant - Abstract
Although the beta(3)-adrenoceptor (AR) has been suggested to be involved in regulation of gut motility and visceral algesia, the precise mechanisms have been unknown. beta(3)-AR has been postulated to have a nonneuronal expression, being initially characterized in adipocytes and subsequently in the smooth muscle. We aimed to investigate the expression of beta(3)-AR in human enteric nervous system and its role in motility and visceral algesia.The expression of beta(3)-AR in human colon myenteric and submucosal plexus was investigated using immunohistochemistry. The effects of a beta(3)-AR agonist on nerve-evoked and carbachol-induced contractions as well as somatostatin release were investigated in strips of human colon. The effect of an agonist on diarrhea and visceral pain was investigated in vivo in rat models.beta(3)-AR is expressed in cholinergic neurons in the myenteric plexus and submucosal plexus of human colon. Activation of beta(3)-AR causes the release of somatostatin from human isolated colon. In a rat model of visceral pain, beta(3)-AR agonist elicits somatostatin-dependent visceral analgesia. beta(3)-AR agonists inhibit cholinergically mediated muscle contraction of the human colon, as well as chemically induced diarrhea in vivo in a rat model.This is the first demonstration of expression of beta(3)-AR in the enteric nervous system. Activation of these receptors results in inhibition of cholinergic contractions and enhanced release of somatostatin, which may lead to visceral analgesia and inhibition of diarrhea. Therefore, beta(3)-AR could be a novel therapeutic target for functional gastrointestinal disorders.
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- 2007
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6. Hydrogen Sulfide Is a Novel Prosecretory Neuromodulator in the Guinea-Pig and Human Colon
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Thomas Frieling, Florian Zeller, Roberto De Giorgio, Michael Schemann, Rudolf Schicho, Isao Ishii, Claus von Weyhern, Dagmar Krueger, Hideo Kimura, Barbara Campi, Schicho R., Krueger D., Zeller F., Von Weyhern C.W., Frieling T., Kimura H., Ishii I., De Giorgio R., Campi B., and Schemann M.
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Adult ,Male ,medicine.medical_specialty ,Potassium Channels ,Colon ,Guinea Pigs ,Receptor potential ,TRPV1 ,Cystathionine beta-Synthase ,TRPV Cation Channels ,Pharmacology ,Cell Line ,chemistry.chemical_compound ,symbols.namesake ,Desensitization (telecommunications) ,Internal medicine ,medicine ,Animals ,Humans ,Cysteine ,Hydrogen Sulfide ,Intestinal Mucosa ,Receptor ,Aged ,Aged, 80 and over ,Dose-Response Relationship, Drug ,Hepatology ,Cystathionine gamma-Lyase ,Gastroenterology ,Middle Aged ,Interstitial cell of Cajal ,Endocrinology ,chemistry ,Capsaicin ,symbols ,Tetrodotoxin ,Calcium ,Female ,Capsazepine - Abstract
Background & Aims: Hydrogen sulfide (H2S) has been suggested as a novel gasomediator. We explored its unknown neuromodulatory role in human and guinea-pig colon. Methods: We used immunohistochemistry to detect H2S-producing enzymes cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS) in enteric neurons, Ussing chambers to measure mucosal ion secretion, and neuroimaging with voltage- and Ca++-sensitive dyes to record H2S effects on guinea-pig and human enteric neurons. Results: More than 90% of guinea-pig and human submucous and myenteric neurons were colabeled for CSE and CBS. Myenteric interstitial cells of Cajal were CSE-immunoreactive. The exogenous H2S donor NaHS (0.2–2.5 mmol/L) concentration-dependently increased chloride secretion in human and guinea-pig submucosa/mucosa preparations, but not in the colonic epithelial cell line T84. The secretory response was reduced significantly by tetrodotoxin (0.5 μmol/L), capsaicin desensitization (10 μmol/L), and the transient receptor potentials vanilloid receptor 1 antagonist capsazepine (10 μmol/L). The endogenous H2S donor L-cysteine also induced secretion that was diminished significantly by capsaicin desensitization, the CBS inhibitor amino-oxyacetic acid, and the CSE inhibitor propargylglycine. NaHS increased spike discharge in 23% of guinea-pig and 36% of human submucous neurons, but had no effect on Ca++ mobilization in cultured guinea-pig enteric neurons. This excitatory response was reduced significantly by capsaicin desensitization and capsazepine, but not by glibenclamide (10 μmol/L). Conclusions: The presence of H2S-producing enzymes in human and guinea-pig enteric neurons, the excitatory action on enteric neurons, and the prosecretory effects of NaHS suggest H2S as a novel gut-signaling molecule. Its action mainly involves transient receptor potentials vanilloid receptor 1 receptors on extrinsic afferent terminals, which in turn activate enteric neurons.
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- 2006
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7. Region-specific effects of STW 5 (Iberogast®) and its components in gastric fundus, corpus and antrum
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A. Ruhl, Klaus Michel, Florian Zeller, Michael Schemann, and B. Hohenester
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medicine.medical_specialty ,Guinea Pigs ,Gastric motility ,Pharmaceutical Science ,Motility ,In Vitro Techniques ,Pharmacology ,Inhibitory postsynaptic potential ,Gastroenterology ,Iberogast ,Gastrointestinal Agents ,Internal medicine ,Drug Discovery ,medicine ,Animals ,Antrum ,Gastrointestinal agent ,Gastric fundus ,Plant Extracts ,business.industry ,Stomach ,digestive, oral, and skin physiology ,Muscle, Smooth ,medicine.anatomical_structure ,Complementary and alternative medicine ,Molecular Medicine ,Gastrointestinal Motility ,business - Abstract
Functional dyspepsia (FD) is a disorder that involves impaired gastric accommodation, antral hypomotility, and upper abdominal pain. The herbal drug STW 5 (Iberogast) is used to successfully treat FD patients. Here, we report in vitro data revealing the mode of action of STW 5 and its individual herbal extracts on gastric motility. STW 5 evoked a relaxation of the proximal stomach but increased antral motility. Both effects are myogenic. The extracts of Angelica root, chamomile flower and liquorice root mimicked the inhibitory effects in the proximal stomach whereas the extracts of greater celandine herb, Melissa leaf, caraway fruit and bitter candy tuft increased motility of the proximal stomach. All extracts increased motility in the antrum comparable to the effects of STW 5. We conclude that the differential effects of STW 5 on proximal and distal stomach motor activity are not caused by solely spasmolytic or anti-spasmolytic effects of the individual components. It is suggested that the individual extracts target transduction mechanisms that are specifically expressed in the proximal vs. distal stomach. We present a rationale for the differential effect of STW 5 which is a result of the combined actions of its individual components and reason that the inhibitory effects in the proximal and the excitatory effects in the distal stomach may contribute to symptom relief in FD patients treated with STW 5 (Iberogast).
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- 2006
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8. Neurochemical coding and projection patterns of gastrin-releasing peptide-immunoreactive myenteric neurone subpopulations in the guinea-pig gastric fundus
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Michael Schemann, Uwe Firzlaff, Holger Sann, Dania Reiche, and Helga Pfannkuche
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endocrine system ,medicine.medical_specialty ,Muscularis mucosae ,Enkephalin ,Guinea Pigs ,Myenteric Plexus ,Substance P ,Biology ,Choline O-Acetyltransferase ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Nerve Fibers ,Gastrin-releasing peptide ,Internal medicine ,mental disorders ,Image Processing, Computer-Assisted ,medicine ,Animals ,Neuropeptide Y ,Gastric Fundus ,Neurons ,Enkephalins ,Neuropeptide Y receptor ,Immunohistochemistry ,Retrograde tracing ,Choline acetyltransferase ,humanities ,Endocrinology ,Gastrin-Releasing Peptide ,nervous system ,chemistry ,Phosphopyruvate Hydratase ,Enteric nervous system ,hormones, hormone substitutes, and hormone antagonists - Abstract
The aim of this study was to characterise the projection and neurochemical coding patterns of gastrin-releasing peptide (GRP)-containing subpopulations of myenteric neurones in the guinea-pig gastric fundus. For this purpose, we used retrograde tracing with the dye DiI and immunohistochemistry against GRP, choline acetyltransferase (ChAT), enkephalin (ENK), substance P (SP) and neuropeptide Y (NPY). Cell counts revealed that 44% of the myenteric neurones were GRP-positive. Of the GRP-positive neurones, 92% were ChAT-positive and, hence, 8% were presumptively nitric oxide synthase positive (NOS). The GRP-positive subpopulations were ChAT/GRP (40% of all GRP neurones), ChAT/NPY/GRP (25%), ChAT/SP/GRP/±ENK (20%), ChAT/ENK/GRP (8%), NOS/NPY/GRP/±ENK (5%) and NOS/GRP (3%). The tracing experiments revealed the relative contributions of the various GRP-positive subpopulations to the innervation of the circular muscle and the mucosa. GRP immunoreactivity was detected in 46 and 38% of the DiI-labelled muscle and mucosa neurones, respectively. GRP was almost exclusively found in ascending ChAT-positive mucosa and muscle neurones. The populations encoded ChAT/SP/GRP/±ENK and ChAT/ENK/GRP projected predominantly to the circular muscle, whereas the ChAT/NPY/GRP and ChAT/GRP populations had primarily projections to the mucosa. GRP was colocalised with ChAT, ENK and/or SP in varicose nerve fibres innervating the circular muscle and the muscularis mucosae, whereas in the mucosal epithelium GRP was mainly present in nerve fibres containing ChAT and NPY. The data suggest that in the guinea-pig gastric fundus, the ChAT/SP/GRP/±ENK and ChAT/ENK/GRP neurones are ascending excitatory muscle motor neurones, whereas the ChAT/NPY/GRP and ChAT/GRP neurones are very likely involved in the regulation of mucosal functions.
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- 2000
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9. Immunohistochemical evidence for the presence of calbindin containing neurones in the myenteric plexus of the guinea-pig stomach
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S. Hoppe, Michael Schemann, Dania Reiche, Helga Pfannkuche, and Klaus Michel
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Male ,Calbindins ,medicine.medical_specialty ,Guinea Pigs ,Myenteric Plexus ,Biology ,Calbindin ,Choline O-Acetyltransferase ,Guinea pig ,Nerve Fibers ,S100 Calcium Binding Protein G ,Internal medicine ,mental disorders ,medicine ,Animals ,Humans ,Antrum ,Myenteric plexus ,Neurons ,General Neuroscience ,Stomach ,digestive, oral, and skin physiology ,NADPH Dehydrogenase ,Immunohistochemistry ,Choline acetyltransferase ,Rats ,Endocrinology ,nervous system ,Calbindin 1 ,Cholinergic ,Female ,Enteric nervous system ,Chickens ,Acetylcholine ,medicine.drug - Abstract
Using immunohistochemistry we studied the presence of calbindin in myenteric neurones of the guinea-pig stomach. A rabbit anti recombinant rat calbindin-D28k (CALB) stained 12, 12 and 25% of all myenteric neurones in the fundus, corpus and antrum, respectively. A rabbit anti recombinant human CALB stained 4, 4 and 16%, respectively. A mouse monoclonal antibody against the chicken intestinal CALB showed no labelling. In all regions most calbindin neurones were additionally choline acetyltransferase (ChAT) positive while only a small proportion exhibited nicotinamide adenosine dinucleatide phosphate (NADPH)-diaphorase-activity. Numerous calbindin -positive varicose nerve fibres were present within myenteric ganglia, rarely detectable in the muscle layers and virtually absent in the mucosa. This study demonstrated that a supopulation of cholinergic myenteric neurones in the stomach contain calbindin and suggested that many of these neurones fulfil interneuronal tasks.
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- 1999
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10. Small intensely fluorescent cells of the rat paracervical ganglion synthesize adrenaline, receive afferent innervation from postganglionic cholinergic neurones, and contain muscarinic receptors
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Rachid Serghini, Jean-Paul Rousseau, Marie-Jeanne Prud'homme, Michael Schemann, Yves Tillet, and Eric Houdeau
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medicine.medical_specialty ,Epinephrine ,Tyrosine 3-Monooxygenase ,Fluorescent Antibody Technique ,Dopamine beta-Hydroxylase ,Cell Line ,Choline O-Acetyltransferase ,Rats, Sprague-Dawley ,Internal medicine ,Muscarinic acetylcholine receptor ,medicine ,Animals ,Cholinergic neuron ,Molecular Biology ,Cell Size ,Neurons ,Afferent Pathways ,Ganglia, Sympathetic ,Tyrosine hydroxylase ,Chemistry ,Phenylethanolamine N-Methyltransferase ,General Neuroscience ,Pargyline ,Immunohistochemistry ,Receptors, Muscarinic ,Rats ,Ganglion ,medicine.anatomical_structure ,Endocrinology ,Catecholamine ,Autonomic Fibers, Postganglionic ,Cholinergic ,Female ,Neurology (clinical) ,Acetylcholine ,Developmental Biology ,medicine.drug - Abstract
In the paracervical ganglion (PCG) of the rat, double-labelling immunofluorescence for catecholamine-synthesizing enzymes and HPLC measurement of catecholamine contents were first performed to evaluate whether intraganglionic small intensely fluorescent (SIF) cells are capable of synthesizing adrenaline. Immunolabelling for tyrosine hydroxylase (TH), dopamine beta-hydroxylase and phenylethanolamine-N-methyl transferase (PNMT) occurred in all SIF cells of the PCG, thus demonstrating the presence of all the enzymes required for adrenaline biosynthesis. Adrenaline levels were undetectable in the PCG but to test the hypothesis that PNMT is active in SIF cells, catecholamines were measured in ganglia of rats pretreated with pargyline, an inhibitor of the monoamine oxidase, the major enzyme involved in the catecholamine degradation. Pargyline treatment increased adrenaline levels in the PCG, thus demonstrating that SIF cells are capable of adrenaline synthesis. The undetectable levels of adrenaline in the PCG of untreated rats suggested a slow rate of biosynthesis of adrenaline in the ganglion. Furthermore, the use of double-labelling showed that SIF cells of the PCG were stained for muscarinic receptors and were approached by varicose ChAT-immunoreactive nerve fibres. Nerve fibres immunoreactive for ChAT were also observed associated with nerve cell bodies of ganglion neurones. Following deafferentation of the PCG, the ChAT-immunoreactive nerve fibres surrounding nerve cell bodies totally disappeared indicating their preganglionic origin, while those associated with SIF cells did not degenerate, which demonstrate that they derived from intraganglionic cholinergic neurones. Taken together, the results show that adrenaline may be a transmitter for SIF cells in the PCG and suggest that cholinergic neurones of the parasympathetic division of the PCG can modulate the SIF cell activity through the activation of muscarinic receptors.
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- 1999
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11. Polarised innervation pattern of the mucosa of the guinea pig distal colon
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Michael Schemann and Michel Neunlist
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Colon ,Guinea Pigs ,Vasoactive intestinal peptide ,Cell Count ,Biology ,Choline O-Acetyltransferase ,Guinea pig ,Neurons, Efferent ,Interneurons ,mental disorders ,Animals ,Neurons, Afferent ,Intestinal Mucosa ,Neurons ,Gastrointestinal tract ,General Neuroscience ,Submucous Plexus ,Anatomy ,Immunohistochemistry ,Retrograde tracing ,Choline acetyltransferase ,Neuronal tracing ,nervous system ,Enteric nervous system ,Vasoactive Intestinal Peptide - Abstract
A neuronal retrograde tracing method with the dye DiI in combination with the immunohistochemical detection of vasoactive intestinal polypeptide (VIP) and choline acetyltransferase (ChAT) was used to characterise the mucosal projection of neurones located in the submucosal plexus of the guinea pig distal colon. VIP and ChAT immunoreactivity labelled separate populations. The mucosa was innervated by descending (59.7 +/- 7.4%), ascending (8.7 +/- 5.0%) and circumferential (31.7 +/- 6.1%) pathways. Descending neurones had longer projections than ascending ones. Descending DiI-labelled neurones were in their vast majority VIP-positive (88.4 +/- 3.6%) and only 3.5 +/- 4.8% of them were ChAT-positive. Conversely, the ascending pathways were predominantly ChAT-positive (90.9 +/- 20.3%) and only 7.8 +/- 20.6% of them were VIP-positive. A significantly larger proportion of DiI-neurones with circumferential projection were ChAT- than VIP-positive (70.9 +/- 15.6 vs. 27.8 +/- 15.7%). The proportion of ascending, descending and circumferential ChAT-positive DiI-neurones was 23:7:70%, respectively, whereas the proportion for VIP-positive DiI-neurones was 2:84:14%, respectively. The results suggest a conservation of the submucosal innervation pattern along the guinea pig colonic mucosa but also reveal differences in the mucosal enteric innervation of other regions of the gastrointestinal tract.
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- 1998
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12. Nitric oxide synthase, choline acetyltransferase, catecholamine enzymes and neuropeptides and their colocalization in the anterior pelvic ganglion, the inferior mesenteric ganglion and the hypogastric nerve of the male guinea pig
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Piers C. Emson, L.-G. Elfvin, Kristina Holmberg, Tomas Hökfelt, and Michael Schemann
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Male ,medicine.medical_specialty ,Inferior mesenteric ganglion ,Tyrosine 3-Monooxygenase ,Guinea Pigs ,Vasoactive intestinal peptide ,Dopamine beta-Hydroxylase ,Calcitonin gene-related peptide ,Biology ,Choline O-Acetyltransferase ,Hypogastric nerve ,Cellular and Molecular Neuroscience ,Catecholamines ,Internal medicine ,medicine ,Animals ,Cholinergic neuron ,Fluorescent Antibody Technique, Indirect ,Ganglia, Autonomic ,Neurons ,Hypogastric Plexus ,Neuropeptides ,Choline acetyltransferase ,Ganglion ,medicine.anatomical_structure ,Endocrinology ,Microscopy, Fluorescence ,nervous system ,Neuron ,Nitric Oxide Synthase - Abstract
By the indirect immunofluorescence method, the distribution of nitric oxide synthase (NOS)-like immunoreactivity (LI) and its possible colocalization with neuropeptide immunoreactivities, with two enzymes for the catecholamine synthesis pathway, tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH), as well as the enzyme for the acetylcholine synthesis pathway, choline acetyltransferase (ChAT) were studied in the anterior pelvic ganglion (APG), the inferior mesenteric ganglion (IMG) and the hypogastric nerve in the male guinea pig. The analyses were performed on tissues from intact animals, as well as after compression/ligation or cut of the hypogastric nerve. In some cases the colonic nerves were also cut. Analysis of the APG showed two main neuronal cell populations, one group containing NOS localized in the caudal part of the APG and one TH-positive group lacking NOS in its cranial part. The majority of the NOS-positive neurons contained ChAT-LI. Some NOS-positive cells did not contain detectable ChAT, but all ChAT-positive cells contained NOS. NOS neurons often contained peptides, including vasoactive intestinal peptide (VIP), neuropeptide tyrosine (NPY), somatostatin (SOM) and/or calcitonin gene-related peptide (CGRP). Some NOS cells expressed DBH, but never TH. The second cell group, characterized by absence of NOS, contained TH, mostly DBH and NPY and occasionally SOM and CGRP. Some TH-positive neurons lacked DBH. In the IMG, the NOS-LI was principally in nerve fibers, which were of two types, one consisting of strongly immunoreactive, coarse, varicose fibers with a patchy distribution, the other one forming fine, varicose, weakly immunoreactive fibers with a more general distribution. In the coarse networks, NOS-LI coexisted with VIP- and DYN-LI and the fibers surrounded mainly the SOM-containing noradrenergic principal ganglion cells. A network of ChAT-positive, often NOS-containing nerve fibers, surrounded the principal neurons. Occasional neuronal cell bodies in the IMG contained both NOS- and ChAT-LI. Accumulation of NOS was observed, both caudal and cranial, to a crush of the hypogastric nerve. VIP accumulated mainly on the caudal side and often coexisted with NOS. NPY accumulated on both sides of the crush, but mainly on the cranial side, and ENK was exclusively on the cranial side. Neither peptide coexisted with NOS. Both substance P (SP) and CGRP showed the strongest accumulation on the cranial side, possibly partly colocalized with NOS. It is concluded that the APG in the male guinea-pig consists of two major complementary neuron populations, the cholinergic neurons always containing NOS and the noradrenergic neurons containing TH and DBH. Some NOS neurons lacked ChAT and could represent truly non-adrenergic, non-cholinergic neurons. In addition, there may be a small dopaminergic neuron population, that is containing TH but lacking DBH. The cholinergic NOS neurons contain varying combinations of peptides. The noradrenergic population often contained NPY and occasionally SOM and CGRP. It is suggested that NO may interact with a number of other messenger molecules to play a role both within the APG and IMG and also in the projection areas of the APG.
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- 1997
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13. Choline acetyltransferase immunoreactivity in the human small and large intestine
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Michael Schemann, Marcello Costa, David Wattchow, Simon J. H. Brookes, and Anthony J. Porter
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Male ,medicine.medical_specialty ,Myenteric Plexus ,Biology ,Choline O-Acetyltransferase ,Intestinal mucosa ,Internal medicine ,Intestine, Small ,medicine ,Humans ,Intestine, Large ,Intestinal Mucosa ,Cholinergic neuron ,Myenteric plexus ,Aged ,Aged, 80 and over ,Neurons ,Cholinergic Fibers ,Hepatology ,Gastroenterology ,Muscle, Smooth ,Middle Aged ,Immunohistochemistry ,Molecular biology ,Choline acetyltransferase ,Small intestine ,Endocrinology ,medicine.anatomical_structure ,Cholinergic ,Female ,Acetylcholine ,medicine.drug - Abstract
BACKGROUND & AIMS: Choline acetyltransferase, an enzyme involved in the synthesis of acetylcholine, is a marker of cholinergic neurons. In this study, the distribution of choline acetyltransferase immunoreactivity in human intestine is described. METHODS: Frozen-section and whole- mount preparations of human small and large bowels were made and labeled with antiserum to choline acetyltransferase. Double labeling with antiserum to neuron-specific enolase enabled the proportion of all neurons that were immunoreactive for choline acetyltransferase to be determined. RESULTS: Nerve fibers, immunoreactive for choline acetyltransferase, were frequent in the circular and longitudinal muscle layers and were widespread in the myenteric and submucous plexuses, but none was observed in the mucosa. Myenteric neurons, immunoreactive for choline acetyltransferase, showed various morphologies, the most common being unipolar and having an irregular outline with several short, lamellar processes. Sixty-four percent of all myenteric neurons were immunoreactive for choline acetyltransferase. Cholinergic submucous neurons were homogeneous in appearance with oval, smooth cell bodies and filamentous dendrites and accounted for 53% of all submucous neurons. A number of cells resembling enteroendocrine cells in the epithelium of the small and large bowels had intense choline acetyltransferase immunoreactivity. CONCLUSIONS: The majority of neurons in human small and large intestines are cholinergic. (Gastroenterology 1996 Aug;111(2):401-8)
- Published
- 1996
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14. Choline acetyltransferase-like immunoreactivity in small diameter neurones of the rat dorsal root ganglion
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Michael Schemann, Holger Sann, Michael Mäder, and Peter W. McCarthy
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Neurofilament ,Calcitonin Gene-Related Peptide ,education ,Central nervous system ,Calcitonin gene-related peptide ,Biology ,Choline O-Acetyltransferase ,Dorsal root ganglion ,Ganglia, Spinal ,mental disorders ,medicine ,Animals ,Neurons, Afferent ,Rats, Wistar ,Cholinergic neuron ,health care economics and organizations ,Cell Size ,Neurons ,General Neuroscience ,Neuropeptides ,Anatomy ,Spinal cord ,Immunohistochemistry ,Choline acetyltransferase ,humanities ,Rats ,medicine.anatomical_structure ,nervous system ,Cholinergic - Abstract
In the rat choline acetyltransferase (ChAT)-like immunoreactivity (ChAT-LI) was demonstrated in the dorsal root ganglion (DRG), in the superficial spinal cord and in the subepithelial layer of the ureter using immunohistochemical techniques. In the L1 DRG, 66% of the neurones were ChAT-LI. They did not express neurofilament immunoreactivity (RT97 negative) but could also contain calcitonin gene-related peptide-like immunoreactivity (CGRP-LI). In the superficial spinal cord and in the subepithelial plexus of the ureter - both areas where high numbers of fine afferent fibres have been demonstrated - CGRP-LI and ChAT-LI were co-distributed, indicating that ChAT can be found in the peripheral and central endings of small afferents. The data provide morphological evidence that a substantial proportion of afferent fibres are cholinergic.
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- 1995
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15. WITHDRAWN: Demonstration of functional neuronal B3- adrenoceptors within the enteric nervous system
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Olutunde Lalude, Anna K. Bassil, Colin A. Campbell, Wendy J. Winchester, Alan Wheeldon, Karen M. Gray, Michael Schemann, Gareth J. Sanger, Ramkumar Thangiah, Shanmugam Vivekanandan, Jennifer L. Stretton, and Selim Cellek
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Hepatology ,Adrenergic receptor ,business.industry ,Gastroenterology ,Medicine ,Enteric nervous system ,Anatomy ,business ,Neuroscience - Published
- 2007
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16. Tu1204 Mode of Action of the Herbal Medicine STW 5 to Evoke Gastric Relaxation
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Shady Allam, Dagmar Krueger, Eva Maria Kugler, and Michael Schemann
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medicine.medical_specialty ,Hepatology ,Wilcoxon signed-rank test ,business.industry ,Internal medicine ,Gastroenterology ,medicine ,Mann–Whitney U test ,business ,Korean version - Abstract
Figure. Main results of the study{BR}(A) Proportion of responders during 4 weeks.{BR}† Proportion of responders: proportion of patients who showed adequate relief of overall epigastric pain or discomfort more than four times out of eight during 4 weeks of therapeutic period. *** P < 0.001 vs. waitlist control group analyzed by Fisher's exact test.{BR}(B) Total score of NDI questionnaire.{BR}NDI-K: Nepean dyspepsia index Korean version, * P < 0.05 vs. waitlist control group analyzed by Mann-Whitney U test, *** P < 0.001 vs. baseline analyzed by Wilcoxon signed rank test.{BR}(C) The scores of FDQoL.{BR}FD-QOL: Functional dyspepsia quality of life, *** P < 0.001 vs. baseline analyzed by Wilcoxon signed rank test.
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- 2015
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17. 679 Altered Behavior of Enteric Neurons in Colonic Biopsies of IBS Patients
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Manuela Götzberger, Michael Schemann, Manfred Kurjak, Sabine Buhner, Nikolaus Lukas, Daniela Ostertag, and Christian Pehl
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Hepatology ,Gastroenterology - Published
- 2015
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18. Differential Effects of Inflammatory Mediators on Ion Secretion in the Guinea-Pig Colon
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Th Frieling, C. Rupprecht, Michael Schemann, and Gisela Dobreva
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medicine.medical_specialty ,Colon ,Guinea Pigs ,Prostaglandin ,Inflammation ,Biology ,Membrane Potentials ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,Secretion ,Ions ,Neurons ,Leukotriene ,Submucous Plexus ,General Medicine ,Electric Stimulation ,Endocrinology ,chemistry ,Tetrodotoxin ,Excitatory postsynaptic potential ,Cholinergic ,Enteric nervous system ,Inflammation Mediators ,medicine.symptom - Abstract
Bi-directional interactions between the enteric nervous system and the immune system play an important role in gut inflammation. We therefore investigated the effects of the inflammatory mediators, prostaglandin (PGD 2 , PGE 2 , PGI 2 , and PGF 2 α ) and leukotriene (LTC 4 ), on guinea-pig colonic secretion and on electrophysiological behaviour of submucosal neurones. In Ussing chambers, all inflammatory mediators evoked a dose-dependent increase in short circuit current (I sc ) that represented electrogenic chloride secretion. The secretory response was significantly reduced by tetrodotoxin (TTX) and atropine suggesting involvement of cholinergic submucosal neurones. Long-term application of prostaglandins and LTC 4 induced TTX- and atropine-sensitive cyclical chloride secretions. Intracellular recordings revealed activation of submucosal neurones by all inflammatory mediators. This activation consisted of depolarisation of the membrane associated with increased spike discharge. Frequently, prostaglandins and LTC 4 induced spontaneous occurrence of cholinergic fast excitatory postsynaptic potentials. Results suggest that the role of the enteric nervous system in neuroimmune interactions consists of a potentiation of the direct epithelial effect of inflammatory mediators by the activation of submucosal neurones. Ongoing nerve-mediated cyclical changes in chloride secretion may be interpreted as the induction of intrinsic alarm programs. The effects of inflammatory mediators may serve as a defense mechanism to dilute noxious substances in the lumen.
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- 1997
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19. 388 Effects of the Herbal Drug STW 5 and Its Individual Components on Human Intestinal Motility
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G.O. Ceyhan, Ihsan Ekin Demir, Olaf Kelber, Dagmar Krueger, Florian Zeller, Michael Schemann, and Shady Allam
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Drug ,Hepatology ,business.industry ,media_common.quotation_subject ,Gastroenterology ,Medicine ,Pharmacology ,business ,media_common ,Intestinal motility - Published
- 2014
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20. Physiological mechanical stimulation activates isolated myenteric neurons
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R. Merkel, G. Dreissen, E.M. Kugler, K. Michel, D. Kirchenbüchler, Michael Schemann, and Gemma Mazzuoli
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Cellular and Molecular Neuroscience ,Endocrine and Autonomic Systems ,Chemistry ,Stimulation ,Neurology (clinical) ,Neuroscience - Published
- 2013
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21. Functions and Imaging of Mast Cell and Neural Axis of the Gut
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Michael Camilleri and Michael Schemann
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Diagnostic Imaging ,Male ,Pathology ,medicine.medical_specialty ,Inflammation ,Cell Communication ,Biology ,Article ,law.invention ,Nerve Fibers ,Optical coherence tomography ,Confocal microscopy ,law ,In vivo ,medicine ,Humans ,Mast Cells ,Receptor ,Retina ,Microscopy, Confocal ,Hepatology ,medicine.diagnostic_test ,Gastroenterology ,Submucous Plexus ,Mast cell ,Gastrointestinal Tract ,medicine.anatomical_structure ,Female ,Enteric nervous system ,medicine.symptom ,Tomography, X-Ray Computed - Abstract
Close association between nerves and mast cells in the gut wall provides the microanatomic basis for functional interactions between these elements, supporting the hypothesis that a mast cell-nerve axis influences gut functions in health and disease. Advanced morphology and imaging techniques are now available to assess structural and functional relationships of the mast cell-nerve axis in human gut tissues. Morphologic techniques including co-labeling of mast cells and nerves serve to evaluate changes in their densities and anatomic proximity. Calcium (Ca(++)) and potentiometric dye imaging provide novel insights into functions such as mast cell-nerve signaling in the human gut tissues. Such imaging promises to reveal new ionic or molecular targets to normalize nerve sensitization induced by mast cell hyperactivity or mast cell sensitization by neurogenic inflammatory pathways. These targets include proteinase-activated receptor (PAR) 1 or histamine receptors. In patients, optical imaging in the gut in vivo has the potential to identify neural structures and inflammation in vivo. The latter has some risks and potential of sampling error with a single biopsy. Techniques that image nerve fibers in the retina without the need for contrast agents (optical coherence tomography and full-field optical coherence microscopy) may be applied to study submucous neural plexus. Moreover, the combination of submucosal dissection, use of a fluorescent marker, and endoscopic confocal microscopy provides detailed imaging of myenteric neurons and smooth muscle cells in the muscularis propria. Studies of motility and functional gastrointestinal disorders would be feasible without the need for full-thickness biopsy.
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- 2013
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22. Tu1396 Identification of Pro-Secretory Components in STW 5, a Fixed Herbal Combination Medicine to Treat Functional Gut Disorders
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Ihsan Ekin Demir, Olaf Kelber, Shady Allam, G.O. Ceyhan, Florian Zeller, Dagmar Krueger, and Michael Schemann
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medicine.medical_specialty ,Hepatology ,business.industry ,Gastroenterology ,Abdominal distension ,Placebo ,medicine.disease ,Bloating ,Tolerability ,Internal medicine ,medicine ,Clinical endpoint ,medicine.symptom ,Adverse effect ,Flatulence ,business ,Irritable bowel syndrome - Abstract
Introduction: Bloating, abdominal distension and flatulence represent very frequent complaints in children with irritable bowel syndrome (IBS). These symptoms are frequently associated to excessive intestinal gas. Hence the reduction of gas production can be considered an effective therapeutic strategy. Alpha-Galactosidase has been shown to reduce gas production and related symptoms in adults. Aim: to evaluate the efficacy and tolerability of Alphagalactosidase on gas related symptoms in pediatric IBS patients. Patients and Methods: this was a single center, randomized, double-blind, placebo-controlled, parallel-group study performed in tertiary care setting. Fifty-two pediatric patients (32 female, median age 8 yrs, range 4-17) with IBS according to Rome III criteria were randomized to receive placebo (n = 25) or Alpha-galactosidase (n = 27) (Sinaire, Promefarm). Both treatments were given as drops or tablets according to body weight at the beginning of each of three meals for 2 weeks. Children were followed up two weeks after the end of treatment. Parent and/or selfassessment of the severity of gas related symptoms (bloating, flatulence, abdominal distension and abdominal spasms) were recorded 3 times daily during the treatment period using a validated visual score. The primary endpoint was reduction in the severity of bloating at the end of treatment compared to baseline. Secondary endpoints were reduction in the severity of other symptoms. As a measure of intestinal gas production, breath hydrogen concentration was measured at baseline and at the end of treatment. Results: α-galactosidase significantly reduced the severity of bloating (p = 0,023) and flatulence (p = 0,005) as compared with placebo. No significant differences were found for abdominal spasms and abdominal distension. The administration of Alpha-galactosidase had no significant effect on breath hydrogen excretion as compared with placebo (p = 0,54). The benefical effects of treatment tended to disappear in both groups at the end of follow-up. No treatmentrelated adverse events were reported during treatment. Conclusions: Although larger and longer trials are needed to confirm our results, Alpha-galattosidase looks a safe and effective agent for managing gas related symptoms in pediatric IBS.
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- 2012
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23. Excitation of Enteric Neurons by Supernatants of Colonic Biopsies From Irritable Bowel Syndrome Patients (IBS) is Linked to Visceral Sensitivity
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Breg Braak, Tamira K. Klooker, Q Li, Sheila Vignali, Sabine Buhner, Guy E. Boeckxstaens, and Michael Schemann
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medicine.medical_specialty ,Endocrinology ,Visceral sensitivity ,Hepatology ,business.industry ,Internal medicine ,Gastroenterology ,medicine ,Monoamine transport ,medicine.disease ,business ,Irritable bowel syndrome - Abstract
but DAT and NET contribute to 5-HT clearance. As the animals mature beyond 3 weeks, SERT function increases while DAT function declines. NET and SERT both contribute to 5-HT clearance in the mucosa of 6 week old guinea pigs. These data indicate that there are redundant transport mechanisms for 5-HT clearance in the gut mucosa. Monoamine transport inhibitors used to treat behavioral problems in pediatric patients could have unanticipated effects on gut function. (Supported by DK57039, DK082967, HD05197)
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- 2011
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24. 725 Cholinergic Agonists Attenuate Inflammation in Macrophages via Interaction With Neuropeptides
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Esmerij P. van der Zanden, Klaus Michel, Guy E. Boeckxstaens, Wouter J. de Jonge, and Michael Schemann
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Hepatology ,Chemistry ,Gastroenterology ,medicine ,Neuropeptide ,Cholinergic ,Inflammation ,Pharmacology ,medicine.symptom - Published
- 2010
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25. P4.11 Exploring short term plasticity in the enteric nervous system: Voltage-sensitive dye recordings of guinea pig myenteric neurons
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P.P. Bertrand, K. Michel, Rebecca L. Bertrand, and Michael Schemann
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Guinea pig ,Cellular and Molecular Neuroscience ,Endocrine and Autonomic Systems ,Voltage-sensitive dye ,Enteric nervous system ,Neurology (clinical) ,Plasticity ,Biology ,Neuroscience - Published
- 2009
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26. 997 Enteric Nitrergic Neuron Defect and Gut Dysfunction in a Rat Model of Parkinson's Disease
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Marisa Faniglione, Mario Colucci, Giovanna Levandis, Marila Cervio, Michael Schemann, Roberto De Giorgio, Simone Vigneri, Rosaria Greco, Marcello Tonini, B. Balestra, Fabio Blandini, and Cristina Tassorelli
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Parkinson's disease ,Hepatology ,business.industry ,Rat model ,Gastroenterology ,medicine ,Anatomy ,medicine.disease ,business ,Nitrergic Neuron ,Neuroscience - Published
- 2009
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27. 978 Mucosal Biopsies from IBS Patients Release Mediators That Sensitize Human Enteric Nervous System (ENS)
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Vincenzo Stanghellini, Roberto De Giorgio, Sabine Buehner, Q Li, Klaus Michel, Sheila Vignali, Giovanni Barbara, Florian Zeller, and Michael Schemann
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Hepatology ,business.industry ,Immunology ,Gastroenterology ,Medicine ,Enteric nervous system ,business - Published
- 2008
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28. Neuronal stretch activated ion channels mediate distension evoked chloride secretion in the guinea pig distal colon
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Thomas Frieling, Eckhard Weber, and Michael Schemann
- Subjects
Guinea pig ,Hepatology ,Chemistry ,Gastroenterology ,Chloride secretion ,Anatomy ,Distension ,Distal colon ,Ion channel ,Cell biology - Published
- 2001
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29. Infection of the enteric nervous system by Borna disease virus
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Michael Schemann, Juergen A. Richt, Gotthold Gaebel, Helga Pfannkuche, and Johannes Seeger
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biology ,Hepatology ,business.industry ,Gastroenterology ,Borna disease virus ,Medicine ,Enteric nervous system ,biology.organism_classification ,business ,Virology - Published
- 2001
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30. Polarized neuroimmune signaling in the submucosal plexus of the guinea pig colon
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Michael Schemann, Thomas Frieling, and Eckhard Weber
- Subjects
Guinea pig ,Submucosal plexus ,Hepatology ,Gastroenterology ,Anatomy ,Biology - Published
- 2000
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31. Optical recordings of excitability in the human enteric nervous system
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Stephan C. Bischoff, Michael Schemann, Michel Neunlist, and Saskia Peters
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Hepatology ,Gastroenterology ,Enteric nervous system ,Biology ,Neuroscience - Published
- 2000
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32. Leukotrienes activate submucosal neurons to evoke cyclical chloride secretion in guinea-pig colon
- Author
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Michael Schemann, G. Dobreva, A. Musial, Thomas Frieling, C. Becker, and C. Rupprechi
- Subjects
Guinea pig ,medicine.medical_specialty ,Endocrinology ,Hepatology ,business.industry ,Internal medicine ,Gastroenterology ,medicine ,Chloride secretion ,business - Published
- 1995
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33. Effects of neurohormonal agents on jejunal contraction spread and transit in the fed dog
- Author
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Michael Schemann and Hans-Jörg Ehrlein
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medicine.medical_specialty ,Contraction (grammar) ,Enkephalin, Methionine ,Saline infusion ,Contraction frequency ,Motility ,Nerve Tissue Proteins ,Secretin ,chemistry.chemical_compound ,Dogs ,Internal medicine ,Methods ,medicine ,Animals ,Neurotensin ,Hepatology ,digestive, oral, and skin physiology ,Gastroenterology ,Feeding Behavior ,Jejunum ,Somatostatin ,Endocrinology ,chemistry ,Gastrointestinal Motility ,Muscle Contraction - Abstract
The jejunal contraction patterns of dogs in response to intravenous infusion of neurotensin, somatostatin, secretin, and met-enkephalin were analyzed. The peptides were given after administration of a noncaloric viscous cellulose meal. A computer was used to determine the length of spread of contraction waves, their contraction force, the contraction frequency, and the motility index. Transit rates of luminal content were assessed videofluoroscopically. During saline infusion the cellulose meal was propelled aborally at a transit rate of 3.1 ± 1.1 cm/s; the corresponding length of spread of contraction waves was 10.3 ± 1.5 cm. All peptides decreased both the transit rate (0.45–1.81 cm/s) and the contraction spread (3.7–6.2 cm). Neurotensin increased the contraction force, but had no effect on contraction frequency and motility index. The other peptides reduced the motility index and the frequency and force of contractions. It was shown that the peptides influenced intestinal contraction patterns and the transit rate of luminal content. The length of spread of contraction waves was found to be most important in the regulation of transit.
- Published
- 1986
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34. Postprandial patterns of canine jejunal motility and transit of luminal content
- Author
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Hans-Jörg Ehrlein and Michael Schemann
- Subjects
medicine.medical_specialty ,Contraction (grammar) ,Jejunum ,Eating ,Dogs ,Internal medicine ,medicine ,Carnivora ,Animals ,Hepatology ,biology ,Computers ,digestive, oral, and skin physiology ,Fissipedia ,Jejunal motility ,Gastroenterology ,biology.organism_classification ,Small intestine ,medicine.anatomical_structure ,Postprandial ,Endocrinology ,Fluoroscopy ,medicine.symptom ,Gastrointestinal Motility ,Mathematics ,Muscle contraction - Abstract
The effects of different nutrient meals and a noncaloric viscous cellulose meal (control) on the motor activity of the canine jejunum were studied. Contraction patterns were detected through six closely spaced, strain-gauge transducers and were analyzed by a computer. Luminal transit was assessed videofluoroscopically. Control meals moved rapidly (1.9 cm/s) along the jejunum. This was achieved by contractions that occurred at a high frequency (12.8 cpm) and propagated over long distances (9.9 cm). In contrast, the transit rates of the nutrient meals were considerably slower (0.5-1.0 cm/s), the frequency of contractions (5.0-8.9 cpm) and the length of spread of contraction waves (2.6-4.8 cm) were decreased, and the incidence of stationary contractions occurring individually or in clusters was increased. A mathematical model incorporating frequency of contractions and the length of their propagation was used to predict the transit of jejunal contents. The results of correlation tests and of the mathematical model revealed that the length of spread of contraction waves was the most important factor that influenced transit.
- Published
- 1986
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35. Galanin mimics slow synaptic inhibition in myenteric neurons
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Michael Schemann, Kenji Tamura, Jackie D. Wood, and Jeffrey M. Palmer
- Subjects
Neurons ,Pharmacology ,Guinea Pigs ,Presynaptic inhibition ,Myenteric Plexus ,Galanin ,Tetrodotoxin ,In Vitro Techniques ,Biology ,Guinea pig ,medicine.anatomical_structure ,Peripheral nervous system ,Intestine, Small ,Synapses ,medicine ,Animals ,Peptides ,Neuroscience - Published
- 1986
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36. Calcitonin gene-related peptide: A potent new peptidergic messenger substance in the myenteric plexus of guinea-pig small intestine
- Author
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K. Tamura, Jackie D. Wood, Jeffrey M. Palmer, and Michael Schemann
- Subjects
Guinea pig ,medicine.anatomical_structure ,Hepatology ,Chemistry ,Gastroenterology ,medicine ,Calcitonin gene-related peptide ,Molecular biology ,Small intestine ,Myenteric plexus - Published
- 1986
- Full Text
- View/download PDF
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