Camilleri, Michael

SummaryBackgroundIrritable bowel syndrome (IBS) patients often experience meal‐associated symptoms. However, the underlying mechanisms are unclear.AimTo determine small intestinal mechanisms of lipid‐induced symptoms and rectal hypersensitivity in IBSMethodsWe recruited 26 IBS patients (12 IBS‐C, 14 IBS‐D) and 15 healthy volunteers (HV). In vivo permeability was assessed using saccharide excretion assay. Rectal sensitivity was assessed using a barostat before and after small bowel lipid infusion; symptoms were assessed throughout. Next, an extended upper endoscopy with probe‐based confocal laser endomicroscopy (pCLE) was performed with changes induced by lipids. Duodenal and jejunal mucosal biopsies were obtained for transcriptomics.ResultsFollowing lipid infusion, a higher proportion of HV than IBS patients reported no pain, no nausea, no fullness and no urgency (P < 0.05 for all). In a model adjusted for sex and anxiety, IBS‐C and IBS‐D patients had lower thresholds for first rectal sensation (P = 0.0007) and pain (P = 0.004) than HV. In vivo small intestinal permeability and mean pCLE scores were similar between IBS patients and HV. Post‐lipid, pCLE scores were higher than pre‐lipid but were not different between groups. Baseline duodenal transient receptor potential vanilloid (TRPV) 1 and 3 expression was increased in IBS‐D, and TRPV3 in IBS‐C. Duodenal TRPV1 expression correlated with abdominal pain (r = 0.51, FDR = 0.01), and inversely with first rectal sensation (r = −0.48, FDR = 0.01) and pain (r = −0.41, FDR = 0.02) thresholds.ConclusionLipid infusion elicits a greater symptom response in IBS patients than HV, which is associated with small intestinal expression of TRPV channels. TRPV‐mediated small intestinal chemosensitivity may mediate post‐meal symptoms in IBS.

AbstractObjectiveSatiety, defined as the duration of the sensation of fullness, is usually measured by validated visual analog scales (VAS) for appetite. Gastric function plays a key role in food intake regulation. However, the association between gastric emptying (GE) and VAS appetite is unknown.MethodsIn this cross‐sectional study, 134 participants (mean [SEM] age = 39 [0.8] years, mean [SEM] BMI = 38 [0.5] kg/m2, 67% females) completed simultaneous measurements of GE and VAS appetite. After a 320‐kcal meal, GE was measured by scintigraphy and appetite by validated 100‐mm VAS for 240 minutes. Satiation was defined as calories consumed to terminate meal and was measured by an ad libitum meal. GE, VAS, and ad libitum meal tests were measured on the same day. Percent of meal retention in the stomach, VAS area under curve (AUC0‐240 min), and overall appetite score (OAS) were calculated. Pearson correlation (ρ) determined the association of GE with VAS appetite and satiation. Appetite components were also analyzed by quartiles based on GE120 min.ResultsGE120 min was correlated with sensation of VAS hungerAUC(0‐240 min) (ρ = 0.24, p = 0.004), fullnessAUC(0‐240 min) (ρ = 0.16, p = 0.05), and OASAUC(0‐240 min) (ρ = 0.20, p = 0.02). Patients with rapid GE120 min had a mean increase in VAS hungerAUC(0‐240 min) by 32 mm/min (15.62%, p = 0.03) compared with normal/slow GE120 min.ConclusionsGE is associated with the sensations of appetite, and rapid GE is associated with increased appetite, which may contribute to weight gain.

LINKED CONTENTThis article is linked to Kuo et al and Mahadeva papers. To view these articles, visit https://doi.org/10.1111/apt.16451 and https://doi.org/10.1111/apt.16470

SummaryBackgroundGastroparesis is a chronic gastric motility disorder. Dopamine D2/D3 receptor antagonists metoclopramide and domperidone are current treatment options but are associated with central nervous system and cardiovascular safety concerns, respectively, precluding chronic use. Trazpiroben (TAK‐906), a dopamine D2/D3 receptor antagonist, is under development for chronic treatment of moderate‐to‐severe gastroparesis. Nonclinical data suggest trazpiroben will have D2/D3 receptor antagonism comparable with metoclopramide or domperidone.AimsTo evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics (effect on prolactin and gastric function) of twice‐daily trazpiroben (5, 25 and 100 mg) in participants with gastroparesis.MethodsThis phase 2a pilot study evaluated gastric emptying using the gastric emptying breath test, with metoclopramide as an internal control. Gastric accommodation and gastroparesis symptoms were assessed using the nutrient drink test and American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index‐Daily Diary, respectively.ResultsOverall, 51 participants were enrolled. Trazpiroben was well tolerated, demonstrating a favourable safety profile without cardiovascular or central nervous system adverse events. All trazpiroben doses were rapidly absorbed and eliminated (t1/2z 4‐5 hours), and D2/D3 receptor target engagement confirmed by increased serum prolactin (peaking at trazpiroben 25 mg). No effect on gastric emptying was demonstrated with trazpiroben or metoclopramide (P > 0.05), although benefits in volume‐to‐fullness were seen at trazpiroben 5 mg (P > 0.05) and 25 mg (88.5 vs −26.3 mL; P = 0.019), and nonsignificant numerical aggregate symptom score improvements were observed with trazpiroben 25 mg vs placebo (P = 0.182).ConclusionsTrazpiroben was well tolerated with a favourable safety profile, supporting its further development for the treatment of gastroparesis. ClinicalTrials.gov identifier: NCT03268941.

Introduction Dermatologic complaints are a common reason for emergency department visits. Methods Retrospective chart review from 1 January 2015 to 31 December 2019. Patients in the Mayo Clinic Emergency Department receiving dermatology consultation were included. Results Dermatitis (24.7%, n = 113), infection (20.4%, n = 93), and drug reaction (10.3%, n = 47) accounted for the majority of diagnoses. Emergency department providers often provide no diagnosis (38%) or a differential diagnosis (22%), and dermatology consultation frequently alters diagnosis (46%) and treatment (83%). Patients receiving in-person consultations are admitted more frequently than those receiving teledermatology consultations (40% vs. 16%, p < 0.001). Primary diagnostic concordance with subsequent dermatology evaluation is high for in-person (94%) and teledermatology (88%) consultations. Discussion This is the largest study of emergency department dermatology consultations in the United States and the first to compare in-person and teledermatology emergency department consultation utilization in clinical practice. These modalities are utilized in a complementary fashion at our institution, with severe dermatologic diagnoses seen in-person. The valuable role of emergency department dermatologists is highlighted by frequent changes to diagnosis and treatment plans that result from dermatology consultation. Furthermore, our data suggest that teledermatology is an effective modality with the potential to expand access to dermatologic expertise in the emergency department setting.

INTRODUCTION: Previous studies in patients with irritable bowel syndrome (IBS) showed immune activation, secretion, and barrier dysfunction in duodenal, jejunal, or colorectal mucosa. This study aimed to measure ileal mucosal expression of genes and proteins associated with mucosal functions. METHODS: We measured by reverse transcription polymerase chain reaction messenger RNA (mRNA) expression of 78 genes (reflecting tight junction proteins, chemokines, innate immunity, ion channels, and transmitters) and 5 proteins (barrier, bile acid receptor, and ion exchanger) in terminal ileal mucosa from 11 patients with IBS-diarrhea (IBS-D), 17 patients with IBS-constipation (IBS-C), and 14 healthy controls. Fold changes in mRNA were calculated using 2 (−Δ, ΔCT) formula. Group differences were measured using analysis of variance. Protein ratios relative to healthy controls were based on Western blot analysis. Nominal P values ( P < 0.05) are reported. RESULTS: In ileal mucosal biopsies, significant differences of mRNA expression in IBS-D relative to IBS-C were upregulation of barrier proteins (TJP1, FN1, CLDN1, and CLDN12), repair function (TFF1), and cellular functions. In ileal mucosal biopsies, mRNA expression in IBS-C relative to healthy controls was reduced GPBAR1 receptor, myosin light chain kinase (MYLK in barrier function), and innate immunity (TLR3), but increased mRNA expression of cadherin cell adhesion mechanisms (CTNNB1) and transport genes SLC9A1 (Na-H exchanger [NHE1]) and INADL (indirect effect on ion transport). DISCUSSION: These data support a role of ileal mucosal dysfunction in IBS, including barrier dysfunction in IBS-D and alterations in absorption/secretion mechanisms in IBS-C.