bluuebunny/crossref_metadata_2025_split huggingface dataset:
A163 MICROCOSTING: ASSESSING HEALTH ECONOMICS IN GI
Authors: Gillies A N , Chow R , Galorport C , Telford J J , Enns R A 
Published: February 2020

Abstract

Background
Micro-costing is a method of collecting precise cost measurements and proves effective in determining economic requirements needed to support health interventions. At St. Paul’s GI Clinic, over 12000 procedures are performed yearly, 80% of which are colonoscopies. Specific standards in the form of appropriate documentation are recommended through Global Rating Scale (GRS) and require yearly auditing to ensure appropriate compliance with these standards. These audits require a time commitment of staff to assess charts. The cost of performing these assessments is not known.

Aims
To determine the cost of annual data collection suggested by GRS for documentation of procedures.

Methods
A retrospective chart review and data analysis of patients (≥ 19 years old) admitted to St. Paul’s GI Clinic for a colonoscopy and/or esophagogastroduodenoscopy (EGD). Data is extracted from the St. Paul’s medical database from August 1st 2018 – August 1st 2019. Since it is a ‘time-and-motion’ study, a stopwatch is used to time the collection of data from each chart. The mean time per-case is derived and used to conduct an appropriate economic analysis, such as total working hours, per-minute salary calculations and equipment costs. The purpose is to determine a yearly cost and identify what the main cost drivers were (time/labor).

Results
As per our annual review format suggested by GRS, 260 procedure reports were reviewed, 150 colonoscopies and 110 EGDs (random sampling of 10 per physician for each type of procedure). A spread sheet outlining key data assessment points for mandatory standard reporting points has been used yearly and was used for this study as well. Mean evaluation time (including recording presence or absence of each item on our standard reporting form): 1 minute and 40 seconds to review the report for a colonoscopy and 1 minute and 33 seconds to review the report for an EGD. A total of 2 hours 51 minutes 16 seconds to review all the EGD reports and 4 hours 8 minutes and 46 seconds for the colonoscopy reports.

Conclusions
It would cost $126 annually to pay a research student, who makes $18/ hour, to collect this quality assurance data required for auditing completeness of physician colonoscopy and EGD procedure documentation according to standards.

Funding Agencies
None
A170 VITAMIN D IN IBD PATIENTS – A RETROSPECTIVE REVIEW
Authors: MacMillan R A , Ponich T 
Published: February 2020

Abstract

Background
Vitamin D is a critical factor in bone remodelling, calcium absorption and may promote anti-inflammatory cytokines in the gut. Inflammatory bowel disease (IBD) is associated with a reduction in serum Vitamin D levels and a chronic inflammatory state, both of which are strong risk factors for bone density loss affecting IBD patients. Despite European and North American IBD maintenance guidelines for Vitamin D monitoring and bone density scans, there are limited North American investigations into factors influencing serum Vitamin D levels in the IBD patient population specifically.

Aims
We investigated whether patient demographics, disease severity indexes and/or inflammatory markers were linked to low serum Vitamin D levels in our IBD patients. We also established the extent of Vitamin D serum deficiencies and supplementation rates in our IBD patients.

Methods
A retrospective chart review of a single clinician’s practice at London Health Science Centre, Victoria Hospital, over the past 20 months, was performed to: 1) assess the frequency of low serum 25-OH Vitamin D (25-OH D) in the IBD patient population and 2) determine whether patient disease severity was linked to lower 25-OH D levels. A multivariate regression analysis was performed assessing Crohn’s Disease (CD) or Ulcerative Colitis (UC) patient factors: age, sex, disease duration, seasonality, current pharmacologic treatments, past surgeries, CD Activity Index, UC Mayo score, C-reactive protein, and fecal calprotectin (Fcal) level.

Results
175 IBD patients had at least one 25-OH D measurement with 71 patients actively on Vitamin D therapy. Of UC and CD patients who were not on Vitamin D therapy, 63% (17/27) and 79% (61/77) were 25-OH D deficient, respectively. 25-OH D levels in the CD population was associated with Vitamin D supplementation (regression coefficient [RC] 23.99, 95% confidence interval [CI] 14.54 to 33.45), summer season ([RC] 9.90, [CI] 0.56 to 19.24), and past bowel resection ([RC] -10.61, [CI] -20.48 to -0.76). 25-OH D levels in the UC population was associated with Vitamin D supplementation (regression coefficient [RC] 47.23, 95% confidence interval [CI] 27.62 to 66.83), and Mayo severity scores ([RC] -23.01, [CI] -41.82 to -4.20). Fcal (78 patients) was inversely associated with 25-OH D levels but the trend was not significant.

Conclusions
Overall, 25-OH D levels were lower in both the UC and CD patient populations relative to the already deficient Canadian population. However, IBD patients are responsive to Vitamin D supplementation. Tools with more objective evidence of disease severity such as UC Mayo score and fcal should be prioritized for identifying the IBD population requiring supplementation.

Funding Agencies
None
A172 EXPERIENCE AND PERCEPTIONS OF SIMETHICONE USE DURING COLONOSCOPY: A SURVEY OF NORTH AMERICAN ENDOSCOPISTS
Authors: Nero J D , Moffatt D C , Park J , Singh H 
Published: February 2020

Abstract

Background
Simethicone is an anti-foaming agent which can be used to decrease the surface tension of air bubbles and improve visualization of colonic mucosa during colonoscopy. Recent studies have found that residual simethicone persists in endoscopes despite reprocessing and disinfection and promotes persistent moisture in endoscope channels. Simethicone residues can theoretically contribute to biofilm formation by providing nutritional milieu for microbial growth, which could increase the risk of transmission of infections among patients. Endoscopists’ perceptions on simethicone use and potential benefits are unknown, and this study aims to start filling this gap.

Aims
To assess experience and perceptions of simethicone use during colonoscopy in North America.

Methods
A REDCap® survey was distributed via email to members of various national professional associations and personal contacts of the study authors. Once the survey is complete, logistic regression analysis will be performed to assess univariate and multivariate associations of simethicone use. Preliminary data are reported in this abstract.

Results
47 practicing endoscopists have responded so far, of which 31 (64%) are surgeons and 16 are gastroenterologists (34%). The participants had been in practice for a median of eight years (range 1 – 34 years) and performed a median of ten colonoscopies per week. All 47 endoscopists practiced in Canada, with representation from seven provinces. Two endoscopists (4%) ask patients to use simethicone orally as part of their bowel preparation. During outpatient colonoscopy, 22 endoscopists (47%) never use simethicone, 19 endoscopists (40%) use simethicone less than 50% of the time, and six endoscopists (13%) use simethicone more than 50% of the time. Endoscopists were divided as to whether certain bowel preparations influenced their use of simethicone (agree or strongly agree 9, 19%; neutral 29, 62%; disagree or strongly disagree 9, 19%), that simethicone use could contribute to the transmission of pathogens through endoscopes (agree or strongly agree 6, 13%; neutral 34, 72%; disagree or strongly disagree 7, 15%), or that simethicone use increases their adenoma detection rate (agree or strongly agree 18, 38%; neutral 21, 45%; disagree or strongly disagree 8, 17%).

Conclusions
Of the current respondents of this survey, just over half (53%) of endoscopists report using simethicone during outpatient colonoscopies. Most reported simethicone use was via the water pump or instrument channel; oral simethicone use maybe minimal. Current respondents were divided in their perception that type of bowel preparation influences their use of simethicone or that simethicone use could contribute to the transmission of pathogens. Many endoscopists believed simethicone use could increase their adenoma detection rate.

Funding Agencies
None
A176 DOUBLE-BALLOON ENDOSCOPIC ULTRASOUND-GUIDED GASTROENTEROSTOMY FOR A MALIGNANT GASTRIC OUTLET OBSTRUCTION: SIMPLIFYING A COMPLEX PROCEDURE
Authors: Singh K S , Chen Y , Bessissow A 
Published: February 2020

Abstract

Background
Endoscopic enteral stenting is the standard of care for gastric outlet obstruction (GOO) despite high risks for stent dysfunction and need for re-intervention. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel technique that has the potential to decrease the risk of stent dysfunction due to tumor tissue in-/over-growth. EUS-GE; however, is technically challenging thereby limiting its widespread use.

Aims
To describe the use of the EUS-GE technique in the management of a GOO using a widely available vascular balloon catheter in aims to demonstrate a modified, more accessible approach to EUS-GE.

Methods
A 76-year-old woman with a suspected distal common bile duct (CBD) cholangiocarcinoma presented with GOO due to extrinsic compression of the duodenum from the CBD mass. After discussion with the patient and family, a decision was undertaken to perform EUS-GE. An enteroscope was inserted to the level of the obstruction. An 0.035 inch x 450 cm guidewire was advanced across the obstruction and into the jejunal loops under fluoroscopy. Two vascular balloon catheters with a compliant balloon diameter reaching up to 46mm (Coda balloon; Cook Medical, Bloomington, Indiana, USA) were placed with the balloons set 10 cm apart. The device was advanced distal to the obstruction over the wire using fluoroscopic guidance. The balloons were then inflated, occluding the distal and proximal ends of the small bowel loop closest to the stomach. This segment was then dilated with infusion of saline and contrast and identified using EUS. An electrocautery-enhanced 15-mm LAMS was then inserted forming the GE.

Results
The patient’s post-procedure course was uncomplicated and she tolerated a stent diet within 24 hours of the procedure with no recurrent obstruction at 3 months follow-up.

Conclusions
EUS-GE is a promising modality for GOO. The described case demonstrates that a modified approach using widely available vascular balloon catheters can effectively facilitate the technical aspect of this procedure. Further studies are needed to validate this novel technique.

Funding Agencies
None
A177 AN UNUSUAL CULPRIT OF AN UPPER GASTROINTESTINAL BLEED IN A PAEDIATRIC PATIENT
Authors: Bortolin K , Chavhan G , Siddiqui I , Ling S C 
Published: February 2020

Abstract

Background
Leiomyomas are benign tumors originating from mesenchymal cells in the muscularis propria that present equally among the sexes usually as localized lesions after the fifth decade. Though rare, esophageal leiomyomas (EL) make up the majority of benign esophageal tumors and are typically located distally. Of all known cases, 2.6% are paediatric. In this population they are 1.71 times more common in females and are often diffuse. Most are slow growing and asymptomatic but when &gt;5cm patients describe dysphagia, vomiting, pain, cough and anorexia. Gastric leiomyomas causing upper gastrointestinal bleeding (UGIB) in adults are reported.

Aims
To discuss a rare cause of UGIB in a child.

Methods
Case report.

Results
We present a 16-year-old Asian boy with no significant past medical history who was transferred to our institution for an UGIB following 3 days of dark black stools, 1 day of coffee ground emesis and pre-syncope. There was no history of non-steroidal anti-inflammatory use.
At presentation he was in shock and received fluid resuscitation and a pantoprazole infusion. His hemoglobin dropped to 81 from 150g/L and corrected with 2 units of packed red blood cells. He was pale, non-dysmorphic with no cutaneous lesions, abdomen was non-distended and non-tender with no masses or hepatosplenomegaly.
An abdominal ultrasound showed mild bowel wall thickening in the cecum and terminal ileum.
Emergent upper endoscopy identified an ulcerated sessile mass at the gastro-esophageal junction. Biopsies revealed polypoid inflamed gastric mucosa with a focal intestinal metaplasia, negative for malignancy.
Magnetic resonance scan characterized a 3.8x4.3x2.5cm lesion in the stomach cardia not extending beyond the serosa with suggested causes including EL and gastrointestinal stromal tumor (GIST).
Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) demonstrated a 2.8x1.8cm well circumscribed homogenous hypoechoic mass in the muscularis propria of the distal esophagus. Histopathology showed bland tumor cells with eosinophilic cytoplasm and nuclei that did not demonstrate atypia. Immunohistochemistry (IHC) stains were positive for smooth muscle actin and desmin. CD117, S-100 and DOG1 were negative. Findings were therefore in keeping with a leiomyoma and not a GIST.
He was referred to the Cancer Genetics clinic for consideration of hereditary leiomyomatosis renal cell cancer and General Surgery for resection.

Conclusions
This case highlights a rare cause of UGIB in a child. EL are scarcely found in children and at present there are no reports of EL causing UGIB. They can be associated with Alport Syndrome or Familial Leiomyomatosis. IHC is an essential diagnostic tool, enabling differentiation of EL from GIST which is important as the latter has malignant potential. EL can be monitored with endoscopy if small but are surgically resected if symptomatic, ulcerated, or growing.

Funding Agencies
None
A189 NON-ALCOHOLIC FATTY LIVER DISEASE AND SEN-V INFECTION: AN INTERIM ANALYSIS
Authors: Rumbolt C B , Minuk G , Osiowy C , Grubert Van Iderstine M 
Published: February 2020

Abstract

Background
Non-alcoholic fatty liver disease (NAFLD) is a common liver disease in which 10–20% of patients are at risk of progressing to cirrhosis. Several risk factors and genetic variants have been proposed to explain such progression but these fail to explain all cases.
SEN-V is a hepatotropic ssDNA virus transmitted by both parenteral and non-parenteral routes. In a previous study we documented serologic evidence of SEN-V infection in 21% of 108 patients with chronic Hepatitis B (HBV), C (HCV) or PBC disease. In a recent Japanese study, HCV patients who were SEN-V positive had higher rates of disease progression than those who were SEN-V negative. Conversely, in an Iranian study, liver enzyme levels were lower in HBV patients co-infected with SEN-V. No study has yet documented the prevalence or impact of SEN-V infection in NAFLD.

Aims
To determine the prevalence and impact of SEN-V infection in NAFLD.

Methods
Thirty-three consecutive patients with NAFLD confirmed on liver biopsy had serologic testing for SEN-V DNA using short and long primer target sequences; sequencing was confirmed by BLAST and phylogenetic analysis. Patients with other causes of chronic liver disease were excluded. ALT levels, NAFLD activity scores (NAS), and fibrosis scores on biopsy were compared between the SEN-V positive and negative groups using Mann-Whitney, t-test, and chi squared as appropriate.

Results
SEN-V serologic testing was positive in 15/33 (45%) NAFLD patients, significantly higher than the 24/108 (21%) reported in non-NAFLD historical controls (p &lt; 0.01). Mean serum ALT levels were similar in the two cohorts (SEN-V positive: 109 +/- 163 versus SEN-V negative: 62 +/- 54 IU/L, p= 0.27). The median NAS scores were identical in both groups (5/8) 95% CI [3,6]. Although the median fibrosis stage in SEN-V positive patients was lower (1.0 95% CI [0,3] vs. 2.5 95% CI [1,4] respectively), the difference did not reach statistical significance (p= 0.27).

Conclusions
Within the limits of this small interim analysis, serologic evidence of SEN-V infection was more common amongst NAFLD patients than historical controls with non-NAFLD chronic liver diseases. However, there were no significant differences in ALT levels, NAS scores or fibrosis stages between SEN-V positive versus negative NAFLD patients. These results suggest that if SEN-V infection has any impact on NAFLD, it may contribute to the development but not severity of the disease.

Funding Agencies
None
A192 DEPLETING ASCL2 IN ESOPHAGEAL ORGANOIDS TO INVESTIGATE ITS ROLE IN STEM CELLS MAINTENANCE
Authors: Hamilton M , Jean D , Giroux V 
Published: February 2020

Abstract

Background
Recently, the first population of stem cells in the esophageal epithelium was identified with the help of the Keratin 15(Krt15) marker. However, little is known about the mechanisms underlying the expansion and the function of stem cells in the esophagus. It was shown that ASCL2, a transcription factor, is upregulated in Krt15+cells compared with Krt15- cells. ASCL2 is a gene target of the Wnt/β-catenin pathway, which act as a regulator of proliferation and maintenance of the stemness state. The ultimate goal of my research project is to determine the role of ASCL2 in the maintenance of esophageal stem cells and to identify his binding partners.

Aims
To investigate the role of ASCL2 in esophageal epithelial biology, we aim at establishingAscl2knockout esophageal organoid lines.

Methods
Lentiviral infection and CRISPR/Cas9 knockout approach were optimized in mouse esophageal organoids. ASCL2was invalidated with CRISPR/Cas9 and/or inducible specific shRNAs in primary mouse esophageal cell line and organoids. Antibodies directed against ASCL2 were also tested to validate cell lines.

Results
First, to optimize lentiviral infection in mouse esophageal organoids, we produced GFP-expressing lentiviruses. Viruses were then concentrated and incubated with a single cell suspension of mouse organoid cells under gentle activation. Infected cells were embedded in Matrigel and grown in organoids. GFP+ cells were then selected using an antibiotic resistance strategy. Second, we used our optimized lentiviral infection protocol to express specific gRNAs in mouse esophageal organoids, which were previously screened in a primary mouse esophageal cell line. Knockout were validated using Western Blot. Invalidation of ASCL2 was performed using CRISPR/Cas9 and inducible shRNAs. We also validated three commercially available ASCL2 antibodies in WB and IF.

Conclusions
ASCL2 is expressed in the mouse esophagus tissue and organoids, and it can be invalidated in cell lines and organoids.

Funding Agencies
NSERC, CRC Tier2
A200 HUMANIZED CELIAC-PRONE EPITHELIUM IN VITRO EXPRESS MHC-II AND CO-STIMULATORY MOLECULES NECESSARY FOR GLUTEN PEPTIDE PRESENTATION
Authors: Rahmani S , Galipeau H J , Su H , Chirdo F G , Didar T F , Verdu E 
Published: February 2020

Abstract

Background
The role intestinal epithelial cells (IECs) play in the breakdown of tolerance to gluten at an early stage in celiac disease (CeD) is unclear. Epithelial stress is a feature of CeD, and although the triggers are largely unknown, it is accompanied by expression of several markers that could be involved in initiation of inflammatory responses. IECs have been shown to express MHC class II (MHC-II) molecules and participate in antigen presentation in several models. Whether IECs can participate in gluten peptide presentation, the major environmental trigger in celiac disease, is unknown. To study this, a model expressing human MHC-II, HLA DQ8 or HLA-DQ2, would be required.

Aims
To develop organoid monolayers from transgenic mice expressing human celiac risk genes: HLA-DQ8 and -DQ2. To investigate conditions leading to the induction of epithelial MHC-II and its main co-stimulatory molecules, CD80, CD86 and CD40, that could enable early gluten peptide presentation.

Methods
In order to show pathophysiological significance of the model, we used two approaches, either induction of inflammation in vivo through gluten sensitization, or direct stimulation of the monolayers using pro-inflammatory cytokines relevant in CeD, such as IFNγ. Mice were sensitized with Pepsin-Trypsin digested gliadin and cholera toxin (CT) once a week for 3 weeks, followed by a challenge phase in which they only received gliadin. Control mice received CT only. We then developed organoid monolayers from the duodenum followed by stimulation with 10 ng/ml IFNγ. Finally, markers necessary for gluten peptide presentation, the expression of MHC-II and its co-stimulatory molecules, were evaluated using flow cytometry.

Results
Both in vivo gluten sensitization and in vitro stimulation of the organoid derived monolayer with IFNγ induced a proinflammatory response, that independently primed the epithelium to express MHC-II molecules (p =0.02 and &lt;0.0001, respectively). When in vivo sensitization and in vitro IFNγ stimulation were combined, epithelial MHC-II expression was further upregulated (p &lt;0.0001). Lastly, only the combination of gluten sensitization and in vitro IFNγ induced expression of MHC-II co-stimulatory molecules, which are necessary for antigen presentation.

Conclusions
Our findings support that gluten induced-inflammation in vivo as well as independent stimuli that release IFNγ enhance the capacity of the IECs to express MHC-II molecules. However, co-stimulatory molecules are only expressed by the epithelium when both gluten tolerance is broken by in vivo sensitization and the organoid monolayers is further exposed to IFNγ. The results support the hypothesis that the epithelium participates in gluten peptide presentation and that this pathway is stimulated by both gluten-dependent and independent inflammation.

Funding Agencies
CIHRSupported by CIHR and a Farncombe Family Grant to EFV and TFD.