bluuebunny/crossref_metadata_2025_split huggingface dataset:
A37 EXPLORING THE PROTEOMICS DIFFERENCES IN CROHN’S DISEASE PATIENTS
Authors: Nogueira de Almeida L , Mainoli B , Filyk A K , Hirota S A , Lu C , Dufour A 
Published: March 2021

Abstract

Background
Canada has the highest prevalence rate of Crohn’s disease (CD) in North America. In Alberta, the yearly cost of anti-inflammatory drugs can be more than $25,000 per person; however, half of the patients do not respond to medication. CD is characterized by lesions in the small intestine due to inflammation, promoting diarrhea and abdominal pain. Prolonged chronic inflammation results in fibrotic strictures that are resistant to anti-inflammatory therapies and promote narrowing of the luminal space that ultimately require surgery. Currently, there is no biomarker to distinguish between the inflammatory or stricturing phenotype.

Aims
AIM 1: Profile serum samples from CD patients using a label-free shotgun-proteomics.
AIM 2: Identify signatures and biomarkers that distinguish inflammatory and fibrotic strictures using a bioinformatics approach.

Methods
Serum samples from 15 CD patients with strictures and 15 CD patients without strictures (inflammatory phenotype), as diagnosed by ultrasound imaging, were analyzed by a standard shotgun-proteomics approach. Briefly, 200 µg of serum proteins were processed in a label-free protocol in combination with the filter-aided sample preparation (FASP) method. Liquid chromatography-tandem mass spectrometry was performed on an Orbitrap Fusion Lumos. Protein identification was accomplished by MaxQuant at a 1% false-discovery rate. Statistical significance was determined by the MSstats package, in the R software. To identify the biological significance of disturbed pathways, it was characterized by the protein-protein interactions and pathway enrichment analysis using String-DB and Metascape.

Results
It was identified a statistically significant protein panel between the two phenotypes. Proteins identified in the strictured group include JAK1 (Tyrosine-protein kinase), CD5 antigen-like protein (regulates inflammatory gene expression in Th17 cells), and neogenin (cell adhesion). Of the inflammatory patients, there was a significant elevation of PFK/FBPase 2 (synthesis and degradation of fructose 2,6-bisphosphate), vinculin (cell-matrix adhesion) and MMP-16/MT3-MMP (matrix metalloproteinase).

Conclusions
The identification of a distinct signature between both phenotypes provide important biological information about the disease progression and are a good sign that a biomarker discovery platform will be capable to differentiate between inflammatory and fibrostenotic strictures from serum samples of CD patients.

Funding Agencies
CAG, CIHRNSERC
A47 SYNTHETIC HUMAN MILK OLIGOSACCHARIDES PREVENT EXPERIMENTAL NECROTIZING ENTEROCOLITIS VIA DIVERGENT TRANSCRIPTOMIC RESPONSES.
Authors: Wu R Y , Li B , Horne R , Ghamel A , Robinson S , Cadette M , Miyake H , Johnson-Henry K , Pierro A , Sherman P M 
Published: March 2021

Abstract

Background
Breastmilk reduces the risk of necrotizing enterocolitis (NEC) in preterm infants, but the bioactive components mediating this effect are not well understood. Human milk oligosaccharides (HMOs) reduce NEC both in humans and in relevant animal models. However, it is unclear if there are functional differences between individual oligosaccharides.

Aims
The objective of this study was to compare the intestinal transcriptome responses of individual HMOs using complementary in vitro and in vivo models of NEC.

Methods
RNA sequencing was performed on Caco-2Bbe1 gut epithelial cells after exposure to commercially-purified 2’-fucosyllactose (2’FL), 3-fucosyllactose, 6’-siallyllactose, lacto-N-tetraose (LNT) or lacto-N-neotetraose for 24hr at 37°C for 24 h (n=3). Signaling pathways were analyzed in murine- and human-derived NEC enteroids by qPCR. To validate these findings, five-day-old mouse pups were orally gavaged formula with or without individual HMOs, followed by NEC induction with hypoxia (5% O2, 95% N2) and lipopolysaccharide (4 mg/kg/day). Coded ileal sections (n=6–7/group) were analyzed for mucosal injury by histology, immune fluorescence, immunohistochemistry, and gene expression via qPCR.

Results
The HMO transcriptome clustered into divergent functional categories including metabolic process, protein processing and responses to external stimuli. Each synthetic HMO induced a unique transcriptome and exhibited varying effects on the intestinal epithelial functions and biological pathways. This was confirmed in the murine model of NEC, as both LNT and 2FL mitigated NEC injury with comparable recovery of intestinal cell proliferation (Ki67) and expression of stem cells (Lgr5+). Both qPCR and immunofluorescence staining showed differences between 2FL- and LNT-fed pups in host inflammatory and immune responses.

Conclusions
This study demonstrates that synthetic HMOs ameliorate intestinal injury in experimental NEC. However, the mechanisms by which individual oligosaccharides act on the intestine differ, suggesting that single synthetic HMOs may not fully recapitulate the benefits of pooled HMOs. Future studies will further delineate structure-function relationships of synthetic HMOs on host intestinal innate and adaptive immune responses.

Funding Agencies
CIHRFerring Canada Medical Student Research grant
A49 BUTYRATE PRESERVES THE EPITHELIAL MITOCHONDRIAL NETWORK DISRUPTED BY THE CROHN’S DISEASE PATHOBIONT ADHERENT-INVASIVE E. COLI
Authors: Hamed S , wang A , Shearer J , Shutt T , Mckay D M 
Published: March 2021

Abstract

Background
Mitochondria exist in a dynamic network that undergoes continuous cycles of fission and fusion that is tightly controlled. Mitochondrial dysfunction is implicated in several autoimmune and inflammatory diseases. Adherent-invasive E. coli (AIEC) is a pathogenic strain of bacteria associated with Crohn’s disease (CD), that can evoke pro-inflammatory responses. Data from our lab showed that AIEC (strain LF82) infection in gut epithelial cells (T84 human cell line) caused dramatic mitochondrial network fragmentation and loss of mitochondrial membrane potential. Short chain fatty acids (SCFA) produced by commensal bacteria in the gut have a wide range of benefits including enhancing mitochondrial biogenesis.

Aims
To determine (1) if sodium butyrate (NaB) treatment can protect against mitochondrial dysfunction induced by AIEC (strain LF82) infection in T84 epithelial cells and then (2) to identify the mechanism by which NaB restores mitochondrial functions.

Methods
We assessed changes in mitochondrial network morphology through confocal microscopy live cell imaging of mitotracker-stained T84 epithelial cells based on unbiased Hoechst-stained nuclei to select the field of view. The effect of NaB on the proliferation of bacteria and their invasion of T84-epithelia was assessed by growth curve analysis and bacterial internalisation assays. Finally, mRNA and protein expression of peroxisome proliferating activator receptor gamma co-activator 1 alpha (PGC1α), a regulator of mitochondrial biogenesis, were assessed by qPCR and Western Blot.

Results
We confirmed that AIEC infection (strain LF82, 108cfu, 4h) induces massive mitochondrial fragmentation in T84 cells (2x105). We also found that cotreatment of T84 cells with NaB (10mM) and LF82 showed increased percentage of fused mitochondrial networks compared to LF82-treated cells. This result was also seen in cells treated with mitochondrial uncoupler dinitrophenol (DNP; 0.1 mM, 2h) and NaB. Moreover, the protective effect of NaB was not related to inhibition of proliferation of the bacteria as we demonstrated that LF82 growth and its invasive phenotype was not compromised by NaB (3-20mM; 0-24hr). In agreement with the effect of LF82 on mitochondrial functions, LF82 significantly reduced PGC1α mRNA expression in T84 cells, that was prevented by co-treatment with NaB.

Conclusions
These data suggest the pathogen disruption of the epithelial mitochondrial network is a component of IBD; thus, identifying mitochondrial fission and fusion pathways as novel therapeutic targets to control enteric inflammation. The data underscore the complex interplay between bacteria and the epithelium, such that commensal organisms may preserve the mitochondrial network in the face of challenge from pathogens that seek to disrupt mitochondrial form and function

Funding Agencies
CIHR
A50 MODULATION OF GOBLET CELL ACTIVITY DURING GIARDIA DUODENALIS INFECTION: A ROLE FOR PAR2
Authors: Fekete E , Amat C B , Allain T , Hollenberg M , Mihara K , Chadee K , Buret A 
Published: March 2021

Abstract

Background
Giardia duodenalis has been shown to alter the structure of the intestinal mucus layers during infection via obscure mechanisms. We hypothesize that goblet cell activity may be disrupted in part due to proteolytic activation of protease-activated receptor 2 (PAR2) by Giardia proteases, resulting in disruption of mucus production and secretion by intestinal goblet cells.

Aims
Characterize alterations in goblet cell activity during Giardia infection, focusing on the roles of Giardia protease activity and PAR2.

Methods
Chinese hamster ovary cells transfected with nano-luciferase tagged PAR2 were incubated with Giardia NF or GSM trophozoites. Cleavage within the activation domain results in release of enzymes into the supernatant. Luminescence in the supernatant was measured as an indication of PAR cleavage by Giardia.
LS174T, a human colonic mucus-producing cell line, was infected with Giardia trophozoites (isolates NF, WB, S2, and GSM). Prior to infection, trophozoites were treated with E64, a broad-spectrum cysteine protease inhibitor, and LS174T were treated with a PAR2 antagonist, a calcium chelator, or an ERK1/2 inhibitor. Quantitative PCR (qPCR) was performed for the MUC2 mucin gene.
Wild-type (WT) and PAR2 knockout (KO) mice were infected with Giardia. Colonic mucus was stained using fluorescein-coupled wheat-germ agglutinin (WGA), and qPCR was performed for Muc2 and Muc5ac.

Results
Giardia trophozoites cleaved PAR2 within the N-terminal activation domain in a cysteine protease-dependent manner. Cleavage was isolate dependent, with isolates that show higher protease activity cleaving at a higher rate.
High protease activity Giardia isolates increased MUC2 gene expression in LS714T. This increase was attenuated by inhibition of Giardia cysteine protease activity, and by antagonism of PAR2, inhibition of calcium release, or inhibition of ERK1/2 activity in LS174T cells.
Both Muc2 and Muc5ac expression were upregulated in the colons of WT mice in response to Giardia infection, while in the jejunum Muc2 expression decreased and Muc5ac expression increased. In KO, no changes in gene expression were seen in the colon in response to Giardia infection, while in the jejunum, Muc2 expression was unchanged and Muc5ac expression decreased. Both WT infected and KO noninfected mice showed thinning of the colonic mucus layer compared to WT controls. There was some recovery in thickness in KO infected mice.

Conclusions
PAR2 plays a significant role in the regulation of mucin gene expression in mice and in a human colonic cell line. Results suggest that Giardia cysteine proteases cleave and activate PAR2, leading to calcium release and activation of the MAPK pathway in goblet cells, ultimately leading to altered mucin gene expression. Findings identify a novel regulatory pathway for mucus production by intestinal goblet cells.

Funding Agencies
CAG, CCC
A57 THE USE AND INTERPRETATION OF HLA-DQ2/DQ8 GENOTYPING BY PEDIATRIC GASTROENTEROLOGISTS
Authors: Moreau B , Robidoux E 
Published: March 2021

Abstract

Background
A recent classification of high and low risk alleles associated with celiac disease (CD) shows that the presence of a single allele (DQA1*05 or DQB1*02; coding together for HLA-DQ2), without a positive genotype (HLA-DQ2 and or HLA-DQ8), represents a risk of developing the disease.

Aims
The aim of this study is to evaluate the use and interpretation of the HLA-DQ2/DQ8 genotyping by pediatric gastroenterologists, as there is no study on the matter and the latest guidelines do not address this risk classification.

Methods
A web-based survey was sent by email to all NASPGHAN (North American society of pediatric gastroenterolgy, hepatology and nutrition) members.

Results
Results 294 pediatric gastroenterologists sent a complete survey. 86,1% use the HLA-DQ2/DQ8 genotyping according mainly to the NASPGHAN and ESPGHAN guidelines. The main indications considered were to exclude CD in a patient on a gluten-free diet with a resolution of his symptoms and in a seronegative patient with equivocal biopsies. A minority would consider the genotyping for screening high risk groups or for making a diagnosis in children with high specific CD antibodies and strong clinical suspicion without performing biopsies, as suggested by the ESPGHAN guidelines. The alleles associated with CD are not well known, but 76,7% the participants are aware of the risk classification. While only 62,8% have access to the complete genotype, 47,8% consider it useful. Nevertheless, 82,6% would still want to know the presence of a low risk allele.

Conclusions
The risk classification of alleles related to CD warrants a modification of the genotyping result with access to the alleles and an adaptation of the guidelines.

Funding Agencies
None
A60 SIGNIFICANCE OF IBD DIAGNOSIS IN THE BC COLON SCREENING PROGRAM
Authors: Bedi H K , Telford J J , Schaeffer D , Penner R M , Atkinson K , Fu Y , Wiesinger H , Rioux K P , Salh B 
Published: March 2021

Abstract

Background
There has been evidence of incidental inflammatory bowel disease (IBD) diagnosis in otherwise asymptomatic patients during colonoscopy to follow-up a positive fecal immunochemical test (FIT). Little is known about the significance of subclinical disease and its progression in this population.

Aims
To determine the incidence and outcome of subclinical IBD in a colon screening program. We hypothesize that the proportion of patients receiving biologic or surgical intervention would be low.

Methods
IBD cases were identified using the BC Colon Screening Program (BCCSP) database; pilot program at 3 sites from 01/2009–11/2013, and province-wide from 11/2013- 12/2017. Inclusion criteria: diagnosis of IBD at BCCSP colonoscopy performed for positive FIT. Exclusion criteria: prior IBD diagnosis, microscopic colitis. Data obtained through chart review included: demographics, endoscopy and histology reports, and medical/surgical treatment.

Results
Of 93,994 colonoscopies, 608 were diagnosed with IBD (0.65%) (Figure 1). Chart review of 245 cases at 10 institutions was performed. 65 patients were excluded. Of the 180 cases included, the average age at diagnosis was 59.6 years and 58.9% were male. 70.6% of patients were Caucasian, 12.2% were East Asian, and 7.8% South-east Asian. 49.4% were diagnosed with Crohn’s disease (CD), 33.9% with Ulcerative Colitis (UC), and 16.7% with indeterminate colitis, with a median follow-up of 25.5 months (0–85.9 months). 62.8% of patients received treatment, with 17.8% requiring biologic therapy, and 1.7% requiring surgical intervention.

Conclusions
This is the largest study assessing subclinical IBD in a colon screening program, with IBD incidence comparable to other publications in this population. However, the high proportion of patients diagnosed with CD is a novel finding. Also, subclinical IBD is not as benign as previously reported as nearly 20% of patients required biologics and/or surgical intervention.

Funding Agencies
None
A76 CLINICAL OUTCOMES, HEALTHCARE UTILIZATION AND COSTS AVOIDED WHEN ROUTINE GASTROENTEROLOGY REFERRALS ARE MANAGED IN PRIMARY CARE SUPPORTED BY CO-DEVELOPED CLINICAL CARE PATHWAYS
Authors: Qureshi A A , Belletrutti P J , Mazurek M S , Jelinski S , Maracle B , Heather G , Kaplan G G , Veldhuyzen Van Zanten S , Swain M , Novak K L 
Published: March 2021

Abstract

Background
The demand for gastroenterology (GI) care in Canada outstrips the supply. In the Calgary Zone, a Central Access and Triage (CAT) model is used as a single point of entry for most GI referrals. In collaboration with primary care, clinical care pathways (CCP) were co-developed and implemented in CAT to support care for common GI referrals in the Primary Care Medical Home (PCMH), avoiding specialty consultation/endoscopy.

Aims
To evaluate the re-referral rate, health outcomes, health system utilization (emergency department (ED) visits and hospitalizations) and costs avoided for referrals managed in the PCMH.

Methods
A prospective observational cohort study of patient referrals declined (closed) by CAT for one of seven indications supported with CCPs: chronic abdominal pain, chronic constipation, chronic diarrhea, dyspepsia, reflux disease, Helicobacter pylori, and irritable bowel syndrome (IBS). Patient clinical records were linked to healthcare administrative databases to extract data: CAT, electronic medical records, discharge databases, and physician billing claims. The Pampalon Deprivation Index evaluated socioeconomic status and education level. Costs according to Canadian Institute for Health Information were estimated for healthcare utilization, consultation and endoscopy.

Results
A total of 3435 referrals were closed for 3274 patients during the study period (July 1, 2018 to May 31, 2020) with dyspepsia being the most common indication (34%). The median age was 45 years, 66% were women and 43% of higher socioeconomic status. Re-referral to GI occurred in 12% leading to 414 endoscopies performed in 348 patients, the majority were normal (93.6%). Two diagnoses of colorectal adenocarcinoma were identified: 1 originally referred for dyspepsia with subsequent colonoscopy for FIT positivity and 1 initially referred for chronic diarrhea but later presented with hematochezia. Over one year, 11% of patients visited an ED yet less than half for the same indication (42.7%, 263/616 visits) with abdominal pain, dyspepsia, and IBS as most common reasons. There were 52 patients with 68 hospitalizations, but only 24% related to GI referral (constipation and abdominal pain). Estimated total costs avoided was $(CA)2,275,344; and with estimated healthcare utilization of $1,440,281, the net costs avoided was $1,477,237.

Conclusions
Innovative, collaborative strategies aimed to better match supple-demand disparity and improve appropriateness of specialty GI referrals are critical to improving timely patient care. Use of CCPs to support care in the PCMH is safe and reduces costs. Continued development of such supports is important to reduce avoidable healthcare utilization.

Funding Agencies
Health Innovation Implementation and Spread (HIIS) Fund
A80 IMPACT OF THE COVID-19 PANDEMIC IN IBD PATIENT CARE
Authors: Dahiya M , Olayinka L , Kaplan G G , Reeb L , Ma C , Panaccione R , Kroeker K 
Published: March 2021

Abstract

Background
The COVID-19 pandemic is affecting patients and healthcare providers worldwide. During the first wave of the pandemic, healthcare delivery shifted from in-person to virtual clinics. Non-urgent and some emergent procedures, including endoscopies, surgeries, and imaging, were delayed to limit the spread and divert resources to COVID-19.

Aims
To assess the impact of the COVID-19 pandemic in care to IBD patients

Methods
A survey study was conducted to assess the impact of the COVID-19 pandemic on IBD care. All patients had a virtual clinic appointment between March to July 2020 at either: University of Alberta Hospital or the University of Calgary Clinic. A section of the survey assessed patient experience of virtual clinics and delays in access to IBD care during the COVID-19 pandemic.

Results
A total of 1581 patients were contacted to complete the survey. 628 patients agreed to participate in the survey, however not all patients completed each component. The mean age of patients who participated in the survey was 48 years (SD = 15.19). 408 patients responded to satisfaction/future use questions: 84.3% (344) patients agree/strongly agree they were comfortable communicating to the physician using the remote system, 77.5% (316) of patients agree/strongly agree that virtual clinic is an acceptable way to receive healthcare services, 84.8% (346) of patients agree/strongly agree they would use virtual care services again, and 82.6% (337) agree/strongly agree they were satisfied with the telehealth system.
Additional challenges were reported by 228 patients. Fear and stress (infection risk/mental health concerns/unemployment) was reported by 57.4% (131) patients. Access to healthcare services, PPE, and community resources was a challenge experienced by 26.3% (60) patients. Additionally, 16.2% (37) patients experienced uncertainty around IBD-specific care, including procedures, treatments, labs, and medications.
Overall, 17.3% of patients reported some type of delay in care by July 2020. Table 1 shows the proportion of patients with a delay by type of care and the median delay: 5.7% of patients with IBD had surgery delayed by a median of 10 weeks (8–16 weeks).

Conclusions
While some delays in healthcare delivery occurred during the first wave of the pandemic, overall 82.7% of patients with IBD maintained their care without disruption. Sustaining healthcare delivery to the IBD community required adaptation to virtual care; however, patient satisfaction was overwhelming positive among patients with IBD.

Funding Agencies
None
A84 THE IMPACT OF GASTROINTESTINAL FOLLOW UP CARE ON HEALTHCARE UTILIZATION IN PATIENTS WITH EOSINOPHILIC ESOPHAGITIS (EOE).
Authors: Alazemi K , Alkhattabi M , Gregor J C 
Published: March 2021

Abstract

Background
EoE is an increasingly recognized gastrointestinal condition that causes significant morbidity ranging from dietary limitations to food impactions requiring emergency room visits. There are a variety of dietary, pharmacologic and endoscopic treatments available but most are more practically guided by a subspecialist familiar and experienced with the condition. There is a perception among some physicians that follow up is sporadic and may be related at least in part to patient compliance

Aims
To assess patients with EoE utilization of health care in LHSC

Methods
We used a retrospective cohort of patients diagnosed with EoE between July 2011 and June 2014 who met the traditional diagnostic criteria. As part of a quality improvement initiative, local follow up over the ensuing 5–7 years was tracked. The impact of follow up on subsequent healthcare utilization was analyzed.

Results
123 patients with biopsy confirmed EoE were analyzed. Follow up appointments were made for 114/123 (92%) patients. 55/123 (45%) had repeat elective endoscopy booked. Only 10/114 (8.7%) of initial appointments went unattended but 15/55 (27.2%) of the patients offered ongoing follow up failed to attend. There were no complications (ie. perforation or bleeding) attributable to any of the procedures. 5/123 (4%) patients required repeat emergency room endoscopy for food impaction. Two patients required this on multiple occasions. 4/5 patients requiring repeat emergency room endoscopy for food impaction had received some sort of follow up, although 4/5 of these had at least one missed appointment. 2/5 patients having emergency room endoscopy required overnight admission. There were no perforations in the cohort.

Conclusions
Patients with a confirmed diagnosis of EoE do have a risk of requiring subsequent emergency endoscopy for food impaction although it is not clear that scheduled follow up significantly reduces that risk. Contrary to the perception of some physicians, patients with EoE are very likely to attend their first follow up visit although the attrition rate for subsequent scheduled visits is not insignificant.

Funding Agencies
None