• Disease
  • Irritable
  • Irritable Bowel
  • Irritable Bowel Syndrome
  • Stephen J Vanner

    Prominent publications by Stephen J Vanner

    KOL Index score: 18965

    BACKGROUND & AIMS: Histamine sensitizes the nociceptor transient reporter potential channel V1 (TRPV1) and has been shown to contribute to visceral hypersensitivity in animals. We investigated the role of TRPV1 in irritable bowel syndrome (IBS) and evaluated if an antagonist of histamine receptor H1 (HRH1) could reduce symptoms of patients in a randomized placebo-controlled trial.

    METHODS: By using live calcium imaging, we compared activation of submucosal neurons by the TRPV1 agonist ...

    Also Ranks for: Patients Ibs |  histamine receptor |  abdominal pain |  irritable bowel syndrome |  submucosal neurons
    KOL Index score: 15951

    Agonist-evoked endocytosis of G protein-coupled receptors has been extensively studied. The mechanisms by which agonists stimulate mobilization and plasma membrane translocation of G protein-coupled receptors from intracellular stores are unexplored. Protease-activated receptor-2 (PAR2) traffics to lysosomes, and sustained protease signaling requires mobilization and plasma membrane trafficking of PAR2 from Golgi stores. We evaluated the contribution of protein kinase D (PKD) and Gβγ to ...

    Also Ranks for: Golgi Apparatus |  plasma membrane |  protein kinase |  gβγ subunits |  gtp binding
    KOL Index score: 15654

    Proteases that cleave protease-activated receptor-2 (PAR(2)) at Arg(36)↓Ser(37) reveal a tethered ligand that binds to the cleaved receptor. PAR(2) activates transient receptor potential (TRP) channels of nociceptive neurons to induce neurogenic inflammation and pain. Although proteases that cleave PAR(2) at non-canonical sites can trigger distinct signaling cascades, the functional importance of the PAR(2)-biased agonism is uncertain. We investigated whether neutrophil elastase, a ...

    Also Ranks for: Neutrophil Elastase |  transient receptor potential |  inflammation pain |  adenylyl cyclase |  vanilloid 4
    KOL Index score: 14557

    Exacerbated sensitivity to mechanical stimuli that are normally innocuous or mildly painful (mechanical allodynia and hyperalgesia) occurs during inflammation and underlies painful diseases. Proteases that are generated during inflammation and disease cleave protease-activated receptor 2 (PAR2) on afferent nerves to cause mechanical hyperalgesia in the skin and intestine by unknown mechanisms. We hypothesized that PAR2-mediated mechanical hyperalgesia requires sensitization of the ion ...

    Also Ranks for: Mechanical Hyperalgesia |  protease‐activated receptor |  par2 agonist |  hypotonic solutions |  vanilloid 4
    KOL Index score: 14421

    OBJECTIVE: To gain mechanistic insights, we compared effects of low fermentable oligosaccharides, disaccharides and monosaccharides and polyols (FODMAP) and high FODMAP diets on symptoms, the metabolome and the microbiome of patients with IBS.

    DESIGN: We performed a controlled, single blind study of patients with IBS (Rome III criteria) randomised to a low (n=20) or high (n=20) FODMAP diet for 3 weeks. Symptoms were assessed using the IBS symptom severity scoring (IBS-SSS). The ...

    Also Ranks for: Patients Ibs |  low fodmap |  controlled trial |  breath tests |  metabolic profiling
    KOL Index score: 13653

    OBJECTIVES: Optimal bowel preparation is vital for the efficacy and safety of colonoscopy. The inconvenience, discomfort, required consumption of large volumes of product, and potential adverse effects associated with some bowel preparations deter patients from colonoscopy and may provide inadequate cleansing. A dual-action, non-phosphate, natural orange-flavored, low-volume preparation containing sodium picosulfate and magnesium citrate (P/MC) is currently being reviewed for bowel ...

    Also Ranks for: Patients Colonoscopy |  2l peg3350 |  bisacodyl tablets |  aronchick scale |  bowel preparations
    KOL Index score: 13378

    Proteases that are released during inflammation and injury cleave protease-activated receptor 2 (PAR2) on primary afferent neurons to cause neurogenic inflammation and hyperalgesia. PAR2-induced thermal hyperalgesia depends on sensitization of transient receptor potential vanilloid receptor 1 (TRPV1), which is gated by capsaicin, protons and noxious heat. However, the signalling mechanisms by which PAR2 sensitizes TRPV1 are not fully characterized. Using immunofluorescence and confocal ...

    Also Ranks for: Protein Kinase |  mice par2 |  thermal hyperalgesia |  sensitization trpv1 |  receptor 2
    KOL Index score: 13275

    Protease-activated receptor (PAR(2)) is expressed by nociceptive neurons and activated during inflammation by proteases from mast cells, the intestinal lumen, and the circulation. Agonists of PAR(2) cause hyperexcitability of intestinal sensory neurons and hyperalgesia to distensive stimuli by unknown mechanisms. We evaluated the role of the transient receptor potential vanilloid 4 (TRPV4) in PAR(2)-induced mechanical hyperalgesia of the mouse colon. Colonic sensory neurons, identified ...

    Also Ranks for: Colonic Afferent |  visceral hyperalgesia |  trpv4 mice |  transient receptor potential |  activated receptor
    KOL Index score: 13074

    OBJECTIVES: Recent studies using the lactulose hydrogen breath test (LHBT) suggest most patients with irritable bowel syndrome (IBS) have small intestinal bacterial overgrowth (SIBO). However, the validity of the LHBT has been questioned, particularly as this test could reflect changes in oro-caecal transit. Therefore, we combined oro-caecal scintigraphy with LHBT in 40 patients who were Rome II positive for IBS to determine if the increase in hydrogen is due to the test meal reaching ...

    Also Ranks for: Breath Test |  patients ibs |  lactulose hydrogen |  lhbt sibo |  caecal transit
    KOL Index score: 12856

    The excitatory ion channel transient receptor potential ankyrin-1 (TRPA1) is prominently expressed by primary afferent neurons and is a mediator of inflammatory pain. Inflammatory agents can directly activate [e.g., hydroxynonenal (HNE), prostaglandin metabolites] or indirectly sensitize [e.g., agonists of protease-activated receptor (PAR(2))] TRPA1 to induce somatic pain and hyperalgesia. However, the contribution of TRPA1 to visceral pain is unknown. We investigated the role of TRPA1 ...

    Also Ranks for: Trpa1 Mice |  receptor potential |  visceral pain |  vmr crd |  spinal neurons
    KOL Index score: 12534

    DNA methyltransferase 3B (DNMT3B) and methylenetetrahydrofolate reductase (MTHFR) are genes which encode enzymes critical to one-carbon metabolism. Polymorphisms in these genes have been implicated in colorectal cancer etiology; however, epigenetic modifications such as gene-specific DNA methylation also affect gene expression. DNA methylation of DNMT3B and MTHFR was quantified in blood leukocytes using Sequenom EpiTYPER® among 272 participants undergoing a screening colonoscopy. DNA ...

    Also Ranks for: Dna Methylation |  adenoma risk |  dnmt3b mthfr |  cpg sites |  genecoding area
    KOL Index score: 12506

    The composition of Na+ currents in dorsal root ganglia (DRG) neurons depends on their neuronal phenotype and innervation target. Two TTX-resistant (TTX-R) Na+ currents [voltage-gated Na channels (Nav)] have been described in small DRG neurons; one with slow inactivation kinetics (Nav1.8) and the other with persistent kinetics (Nav1.9), and their modulation has been implicated in inflammatory pain. This has not been studied in neurons projecting to the colon. This study examined the ...

    Also Ranks for: Ganglia Neurons |  mouse colonic |  dorsal root |  nav18 currents |  mice mice
    KOL Index score: 12467

    Once activated at the surface of cells, G protein-coupled receptors (GPCRs) redistribute to endosomes, where they can continue to signal. Whether GPCRs in endosomes generate signals that contribute to human disease is unknown. We evaluated endosomal signaling of protease-activated receptor-2 (PAR2), which has been proposed to mediate pain in patients with irritable bowel syndrome (IBS). Trypsin, elastase, and cathepsin S, which are activated in the colonic mucosa of patients with IBS and ...

    Also Ranks for: Irritable Bowel Syndrome |  gpcrs endosomes |  patients ibs |  endocytosis par2 |  colonic mucosa
    KOL Index score: 12143

    Mast cells that are in close proximity to autonomic and enteric nerves release several mediators that cause neuronal hyperexcitability. This study examined whether mast cell tryptase evokes acute and long-term hyperexcitability in submucosal neurons from the guinea-pig ileum by activating proteinase-activated receptor 2 (PAR2) on these neurons. We detected the expression of PAR2 in the submucosal plexus using RT-PCR. Most submucosal neurons displayed PAR2 immunoreactivity, including ...

    Also Ranks for: Submucosal Neurons |  mast cell |  par2 receptors |  activated receptor |  activating peptide
    KOL Index score: 12011

    Previously, we showed histamine-mediated sensitization of transient receptor potential (TRP) vanilloid 1 (TRPV1) in patients with irritable bowel syndrome (IBS). Sensitization of TRP ankyrin 1 (TRPA1) and TRP vanilloid 4 (TRPV4) are also involved in aberrant pain perception in preclinical models of somatic pain. Here, we hypothesize that in parallel with TRPV1, histamine sensitizes TRPA1 and TRPV4, contributing to increased visceral pain in patients with IBS. Rectal biopsies were ...

    Also Ranks for: Irritable Bowel Syndrome |  receptor potential |  trpv4 trpa1 |  trp vanilloid |  sensory neurons


    Stephen J Vanner: Influence Statistics

    Sample of concepts for which Stephen J Vanner is among the top experts in the world.
    Concept World rank
    tnbs evoked increase #1
    dilations ttx #1
    colonic cleansing colonoscopy #1
    lowresidue breakfast lrb #1
    genecoding area #1
    nap psmc #1
    assigned dietary regimen #1
    20 ppm series #1
    colonic supernatants #1
    ibs symptoms diet #1
    dietary therapies symptoms #1
    myenteric chamber 50 #1
    efficacy picosulfate #1
    colonoscopy review #1
    dnmt3b dna methylation #1
    nonlabelled neurons #1
    66 28cpg sites #1
    capsaicin carbachol responses #1
    neuroanatomical remodeling #1
    adapter proteins md1 #1
    multiple dietary therapies #1
    trees motoneurons #1
    obps scores #1
    phosphate nap #1
    dnmt3b mthfr #1
    peg solution lrb #1
    standard volume preparation #1
    splitdose traditional arm #1
    30 slow epsps #1
    ibs patients fodmaps #1
    secondorder dendrites #1
    sustained neurochemical #1
    hypothesis sibo #1
    reflex submucous #1
    capsaicin 24 #1
    standardized peeling technique #1
    ibs acupuncture therapy #1
    baseline testing attendees #1
    colonic drg #1
    day hyperexcitability #1
    dilations tetrodotoxin #1
    dilations evoked #1
    female humans nap #1
    time lhbt #1
    submucosal secretomotor neurons #1
    colonic mesenteric nerves #1
    myenteric neurons inputs #1
    safety profile picosalax #1
    detects oro #1
    epans pathways #1

    Key People For Irritable Bowel Syndrome

    Top KOLs in the world
    Douglas A Drossman
    irritable bowel syndrome abdominal pain psychosocial factors
    Nicholas Joseph Talley
    functional dyspepsia irritable bowel syndrome emergency action
    William E Whitehead
    irritable bowel syndrome fecal incontinence abdominal pain
    Emeran A Mayer
    irritable bowel syndrome ibs patients food addiction
    Peter James Whorwell
    irritable bowel syndrome rectal sensitivity ulcerative colitis
    Robin Charles Spiller
    irritable bowel syndrome diverticular disease magnetic resonance

    Stephen J Vanner:Expert Impact

    Concepts for whichStephen J Vannerhas direct influence:Irritable bowel syndrome,  Submucosal neurons,  Ibs patients,  Guinea pig ileum,  Drg neurons,  Colon cleansing,  Submucosal arterioles,  Bowel syndrome.

    Stephen J Vanner:KOL impact

    Concepts related to the work of other authors for whichfor which Stephen J Vanner has influence:Irritable bowel syndrome,  Bowel preparation,  Gut microbiota,  Visceral hypersensitivity,  Abdominal pain,  Mast cells,  Ibs patients.



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    Gastrointestinal Diseases Research Unit (GIDRU), Kingston Health Sciences Centre, 76 Stuart St., K7L 2V7, Kingston, ON, Canada | Gastrointestinal Diseases Research Unit, Queen's University, Kingston General Hospital, Kingston, Ontario, Canada. | Quee