Breen‐Lyles, Margaret K.

AbstractBackgroundColonic transit measurement [geometric center (GC) at 24 and 48 hours] identifies slow transit constipation (STC) in patients with chronic constipation.AimTo evaluate the utility of the difference between GC24 and GC48 (Δ48‐24) to identify STC in adults with chronic constipation.MethodsWe reviewed medical records of 250 patients, aged 18‐75 years, who underwent colonic transit by scintigraphy during 1994‐2019 for investigation of chronic constipation. Data collected included demographics, medical and surgical histories, and anorectal manometry. We used colonic transit from 220 healthy controls to identify the 5th percentile for diagnosing STC: 1.3 at 24 hours, and 1.9 at 48 hours. In addition, the 5th percentile for Δ48‐24 was 0.38 for females and 0.29 for males. Data are reported as median and IQR [Q1, Q3]).Key resultsAmong the 250 patients [median age 42.5 years (IQR 30.75, 56), 84% female], based on GC24 < 1.3, 52 (20.8%) had STC (3 males, 49 females); and based on GC48 < 1.9, 28(11.2%) had STC (3 males, 25 females). Colonic transit was normal in 74.8%. In the groups with normal GC24 and GC48, Δ48‐24 identified an additional 32(15.1%) of 212 female patients and 4 (10.5%) of 38 male patients with slow progression of colonic transit between 24 and 48 hours. Among these 36 patients with abnormal Δ48‐24, 13(36.1%) had evidence of rectal evacuation disorder.Conclusions & InferencesΔ48‐24 measurement on scintigraphic colonic transit can identify an additional 9.2% of STC in patients with constipation without rectal evacuation disorder and can help individualize treatment of chronic constipation.

Background Campylobacter is a leading cause of bacterial enterocolitis in the U.S. and around the world. In addition to the acute morbidity, it is associated with delayed sequelae such as environmental enteropathy and post‐infection irritable bowel syndrome. Host responses to Campylobacter infection are poorly studied due to colonization resistance in mice thereby restricting virulence studies to immortalized cell lines. These models lack the complexity of the host environment. Recent studies have highlighted the use of organoids for studying enteric pathogens. We propose that human organoids provide a unique platform for studying pathogenic mechanisms incorporating unique host (human) and infection (strain) characteristics. Objective To demonstrate human colonic organoids (colonoids) as a model for studying C. jejuni infection. Methods Sigmoid colonic biopsies were collected from healthy volunteers between 18–35 years of age (n=3). Intestinal crypts were isolated, washed and plated in matrigel domes for colonoid formation. Mature colonoids were harvested after 7 days, and dissociated using a 0.05% trypsin solution. These were plated on collagen IV coated plates, generating 2D‐monolayers for infection experiments. Three different C. jejuni strains (Sequence Types 45, 22, 8) were grown to an OD 600 of 1 and used to infect the colonoid monolayers. To assess adhesion and internalization, colonoids were infected for a total of 3 hours after which monolayers were either washed and subsequently lysed (to determine attached plus invaded bacteria) or treated with gentamycin and then lysed (to determine invaded bacteria). Bacterial quantification was done by plating on Mueller Hinton agar. Additional colonoid monolayers were grown on permeable transwell inserts. Baseline transepithelial resistance (TER) of confluent monolayers was recorded and then continuously assessed every hour after the addition of the C. jejuni strains (using impedance spectroscopy in cellZscope) to evaluate changes in barrier integrity. Results All C. jejuni strains attached and invaded colonoid monolayers derived from all three volunteers. Two strains (ST 45 and 22) caused greater adhesion and invasion in all three colonoids compared to the third strain (Adhesion mean (SEM): 4.32 x 10 −2 (2.33 x 10 −3 ), 9.36 x 10 −3 (4.82 x 10 −4 ) vs 7.79 x 10 −3 (3.51 x 10 −3 ); Invasion mean (SEM) 3.47 x 10 −4 (2.13 x 10 −5 ), 2.33 x 10 −4 (1.36 x 10 −4 ) vs 4.57 x 10 −5 (1.73 x 10 −5 ) (ANOVA, p<0.05, n=3/group for both analyses). Additionally, greater drop in TER was seen in colonoid monolayers exposed to the two strains with higher adhesion and invasion (Mean % of baseline TER at 30 hr post‐infection 2.58% (1.21), 14.14% (3.39) vs 42.29% (18.49), p<0.01). These results correlated with virulence of these strains in conventional T84 monolayers. Transcriptomic and proteomic characterization of the C. jejuni infection in these colonoids is in progress. Conclusions Human colonoids are useful to assess the role of the host in infectivity and epithelial barrier responses to C. jejuni infection. Future work involves determining responses in colonoids derived from volunteers with specific characteristics to create unique host‐bacterial infection models. Support or Funding Information Supported by funding from Department of Defense W81XWH‐18‐1‐0074

INTRODUCTION: Increasing rates of obesity have led to increased numbers of bariatric surgeries performed world-wide. However, some patients do not achieve significant weight loss or develop weight regain following these procedures. Other than estimating the size of the gastric remnant at endoscopy or transaxial imaging, there are limited approaches to quantitate the function of the post-surgical stomach in order to evaluate the disparate weight patterns, or to develop strategy for future treatments, e.g., pharmacotherapy or endoscopic intervention. We hypothesize that altered gastric function in the pre- and post-surgical periods may offer an explanation. Studies performed thus far are difficult to interpret due to heterogeneity in approaches to diagnostic evaluation. The aims of this project were: to assess the feasibility of a new protocol for simultaneous evaluation of gastric accommodation and gastric emptying in the post-bariatric state; and to report normative values in healthy volunteers. METHODS: Methods: We utilized single photon emission computed tomography (SPECT) and gamma scintigraphy to concurrently study postprandial gastric accommodation responses and gastric emptying rates of a limited size meal designed for subsequent use in post-bariatric patients. The standard meal consisted of 1 egg and 1 extra egg yolk scrambled with 111 Indium-activated charcoal (∼130kcal, 9.5g fat) and 120mL 2% milk (130kcal, 4.4g fat). Gastric accommodation was measured using 99m Technetium-SPECT. SPECT imaging was obtained concomitant with gastric emptying of the 111 In-labeled meal. Anterior and posterior scans of the abdomen were obtained for estimating gastric emptying parameters every 15 minute until 90 minutes, and then in 30-minute intervals until 240 minutes or complete emptying. RESULTS: Data on 28/30 healthy volunteers (35.7% men; 67% Caucasian) with completed studies to date are shown in the Table 1 (data presented as mean ± standard deviation). Gastric emptying proportion at 1, 2, and 4 hours, T 1/2 , and gastric volumes including accommodation are graphically depicted in Figures 1 and 2, respectively. CONCLUSION: Discussion: This study has demonstrated feasibility of simultaneous measurement of gastric emptying and accommodation and provides normal values; this sets the stage for future baseline and post-operative scans on patients undergoing sleeve gastrectomy.

ABSTRACT The QuantiFERON-TB Gold Plus (QFT-Plus; Qiagen, Germantown, MD) interferon gamma release assay (IGRA) received FDA clearance in 2017 and will replace the prior version of the assay, the QFT-Gold In-Tube (QFT-GIT). Here, we compared performances of the QFT-Plus assay and the QFT-GIT version in a diverse patient population, including patients undergoing evaluation for or follow-up of latent tuberculosis infection (LTBI; n = 39) or active TB infection ( n = 3), and in health care workers (HCWs; n = 119) at Mayo Clinic (Rochester, MN). Compared to the QFT-GIT, the QFT-Plus assay showed 91.2% (31/34) positive, 98.4% (124/126) negative, and 96.6% (156/161) overall qualitative agreement among the 161 enrolled subjects, with a Cohen's kappa value of 0.91 (excellent interrater agreement). Among the 28 patients diagnosed with LTBI at the time of enrollment, the QFT-GIT and QFT-Plus assays agreed in 24 (85.7%) patients; in all four discordant patients, the positivity of the QFT-GIT or QFT-Plus IGRA was associated with low-level interferon gamma (IFN-γ) reactivity, ranging from 0.36 IU/ml to 0.66 IU/ml. Additionally, we document a high degree of correlation between IFN-γ levels in the QFT-GIT TB antigen tube and each of the two QFT-Plus TB antigen tubes, as well as between the QFT-Plus TB1 and TB2 tubes (Pearson's correlation coefficients [ R ] > 0.95). Overall, we show comparable results between the QFT-GIT and QFT-Plus assays in our study population composed of subjects presenting with a diverse spectrum of TB infections. Our findings suggest that the necessary transition to the QFT-Plus assay will be associated with a minimal difference in assay performance characteristics.