bluuebunny/crossref_metadata_2025_split huggingface dataset:
A69 LONG-TERM EFFECTS OF TORKELSON SYNDROME
Authors: Dinn S E , Wrobel I , Bhandal S , Brundler M 
Published: February 2022

Abstract

Background
Torkelson Syndrome is a rare, familial enteropathy with villous edema causing recurrent episodes of life threatening vomiting and secretory diarrhea in childhood, with children being well between episodes. The only description, of a Mennonite family from southern Alberta, suggests normal growth and no long term sequelae. Severe laboratory abnormalities common during bouts of diarrhea (hypoalbuminemia, neutropenia and electrolyte abnormalities) normalize in the asymptomatic phase except for decreased IgG subclasses. Typical findings from the duodenum and jejunum do not vary between acute episodes and when well. The pathophysiology is poorly understood, with acute episodes thought to be triggered by a non-specific infection in the setting of IgG2 deficiency.
Apolipoprotein A-IV (APOA4) mutation has been documented in Torkelson syndrome. APOA4 is exclusively expressed in proximal small intestine villous enterocytes. It is thought to be involved in regulating pathways that control inflammation in enterocytes, resulting in decreased inflammation. It may prevent recruitment of leukocytes to inflamed intestinal enterocytes by suppressing P-selectin in the endothelial cells. Fully functioning APOA4 decreases secretion of IL-4 and TNF-a. In theory, abnormalities in APOA4, could result in a robust, unopposed inflammatory response in the small intestine.

Aims
Report possible long-term sequelae of Torkelson Syndrome.

Methods
Case report.

Results
13 year old male with Torkelson syndrome presents with short stature and iron deficiency anemia responsive to oral iron. His weight is at the 0.1%ile, height at the 0.4%ile and BMI at the 1.6%ile.
Life time hypoalbuminemia (20g/L) indicates chronic protein-losing enteropathy. Vitamin D is chronically low but responds to oral supplementation. IgA and IgM are normal, but IgG and its subclasses are decreased. Liver enzymes and electrolytes, including calcium and phosphate, outside of episodes of diarrhea are normal.
Endoscopy shows prominent, thick villi, with fern-like appearance in the duodenum with normal stomach, esophagus, terminal ileum and colon. Biopsy results are consistent with previously described features of Torkelson syndrome with no additional abnormalities. MRE shows mild dilatation of the jejunum with hypertrophic conniventes with fat content. Abdominal ultrasound shows hepatomegaly with coarse echotexture and normal elastography. He has delayed bone age and low bone density.

Conclusions
Patients with Torkelson syndrome, despite their recurrent episodes of life threatening vomiting and secretory diarrhea in childhood, were thought to have no long term sequelae including normal growth.
Our patient, presents with chronic iron deficiency anemia, short stature, delayed bone age and density, and hepatomegaly of unknown significance. This case may broaden our knowledge of this poorly described condition to inform long term management of these patients.

Funding Agencies
None
A93 USEFULNESS OF A NOVEL SMARTPHONE APP IN GASTROINTESTINAL ENDOSCOPY TO TRACK PROCEDURE NUMBERS AND THERAPEUTIC INTERVENTIONS
Authors: Yang D Y , Krahn T , Wang C , Decanini-Trevino J , Wasilenko S , Kroeker K , Davila-Cervantes A , Baugmart D C , Montano-Loza A J , Halloran B , Zepeda-Gomez S 
Published: February 2022

Abstract

Background
Endoscopy teaching is an integral part of gastroenterology (GI) training. Though the number of completed endoscopic procedures does not equate competency, procedure tracking is useful for monitoring an individual’s learning progress. Currently, procedure tracking is typically done on an informal basis using paper or electronic spreadsheets. These methods are non-standardized and may not be shareable between trainees and their programs.
Endostation is a smartphone app created by the University of Alberta Therapeutic Endoscopy Program to facilitate the tracking of endoscopic procedures. The app allows trainees to record the number of endoscopies and details such as cecal intubation (CI), ERCP cannulation, and therapeutic interventions. Data can be accessed by users via the app and website (www.endostation.ca), allowing for close monitoring of trainees’ learning progress.

Aims
Our primary objective was to evaluate the usefulness of the app for tracking the number of endoscopic procedures and therapeutic interventions. Our secondary objective was to evaluate the acquisition of endoscopy skills based on quality endoscopic parameters such as CI rate and ERCP cannulation rate.

Methods
One therapeutic endoscopy fellow and two GI residents were recruited for the study. Participants were asked to document their procedures over the study period (9-month for therapeutic endoscopy fellow, 12-month for GI residents). Total number of procedures was summed for each trainee. Acquisition of endoscopy skills was tracked by comparing success rates of CI and ERCP cannulation at different points within the study period.

Results
The therapeutic endoscopy fellow recorded 415 cannulation attempts, 209 sphincterotomies, 282 stone extractions, 71 plastic stent placements, and 37 metal stent placements. There was a significant difference in the cannulation success rate when comparing the 1st trimester and the 3rd trimester of the study period (68% vs 85%; p= 0.0012) (Fig 1).
The two GI residents respectively recorded 335 and 170 colonoscopies plus 454 and 305 gastroscopies. Resident 1 recorded 58 polypectomies, 9 esophageal variceal banding, and 16 non-variceal hemostasis. Resident 2 recorded 17 polypectomies, 12 esophageal variceal banding, and 9 non-variceal hemostasis. The CI success rate was significantly higher for both residents when comparing the first 4 months of training vs the last 4 months [24% vs 88% for resident 1 (p=0.00001); 15% vs 42% for resident 2 (p= 0.001)] (Fig 1).

Conclusions
The smartphone app (Endostation) was a useful tool for endoscopic procedure tracking. Data from the app was useful in demonstrating improvement in CI rate and ERCP cannulation rate over the study period.

Funding Agencies
None
A120 AUTOMATED BOWEL PREPARATION DETECTION WITH DEEP. CONVOLUTIONAL NEURAL NETWORKS
Authors: Low D J , Hong Z , Mukherjee A , Jugnundan S , Grover S 
Published: February 2022

Abstract

Background
Introduction: Bowel preparation inadequacy has been shown to increase post-colonoscopy colorectal cancer. As such, the USMSTF recommends repeating colonoscopy within 1 year if bowel preparation is inadequate. However, bowel preparation documentation is variable in clinical practice, and physician recommendations adherent to USMTF guidelines are inconsistent.

Aims
Aims: We present an automated computer assisted method using deep convolutional neural networks to detect bowel preparation and adequacy of bowel preparation with the Boston Bowel Preparation Scale (BBPS).

Methods
Methods: We extracted 38523 images of colonic lumen between 2015 and 2017 from screening colonoscopies. Bowel preparation scores were assessed with BBPS. Adequate bowel preparation was defined as BBPS ≥2, and inadequate bowel preparation was defined as BBPS &lt;2. The dataset was split into 26966 images for training, 7704 for validation, and 3853 for testing. Training data was sampled with replacement from a multinomial distribution to balance subclass distributions in each batch. We developed 2 convoluted neural networks (CNN) using PyTorch with a Densenet-169 backbone pre-trained on ImageNet and fine-tuned on our data for classifying adequacy of bowel preparation (binary) and for subclassification of BBPS (multi-class). We used Adam optimiser with an initial learning rate of 3x10-4 and a scheduler to decay the learning rate of each parameter group by 0.1 every 7 epochs along with focal loss as our criterion for both classifiers.

Results
Results: The overall accuracy on the test data set for BBPS subclassification was 0.91. The sensitivity for BBPS 0, 1, 2 and 3 were 0.84, 0.91, 0.86, and 0.96, respectively. The specificity for BBPS 0, 1, 2, and 3 were 1.00, 0.98, 0.95, and 0.93, respectively. The overall accuracy of the test data set for adequacy of bowel preparation was 0.97. The sensitivity for adequacy of bowel preparation for BBPS &lt;2 and BBPS ≥2 was 0.92 and 0.99, respectively. The specificity for adequacy of bowel preparation for BBPS &lt;2 and BBPS ≥2 was 0.99 and 0.92, respectively.

Conclusions
Conclusion: We present an automated computer-assisted detection method of bowel preparation with deep convolutional neural networks. The algorithm is capable of accurate classification of adequacy of bowel preparation (97%) and subclassification of bowel preparation (91%) with high sensitivity and specificity. This algorithm can be applied to automate documentation of bowel preparation and adequacy of bowel preparation. Additional studies will need to be conducted to demonstrate its applicability in real-time colonoscopy.

Funding Agencies
None
A206 GALLSTONE IMPACTION IN THE DESCENDING COLON WITH SUCCESSFUL ENDOSCOPIC REMOVAL
Authors: Malik G , Yang D Y , Wong K 
Published: February 2022

Abstract

Background
Gallstone impaction in the colon is a rare complication of cholelithiasis, typically because of gallstones migrating into the colon via a cholecystocolonic fistula. Gastrointestinal obstruction from gallstones only develops in 0.3–0.5% of patients with cholelithiasis and accounts for 0.095% of all mechanical bowel obstruction. Successful treatment has been described with endoscopic and surgical techniques.

Aims
This report aims to present a case of colonic obstruction from gallstone that was successfully treated endoscopically.

Methods
We conducted a retrospective chart review on one patient including assessing the history of presenting illness along with biochemical, radiographic, and endoscopic results. We then conducted a narrative literature review on this subject matter.

Results
An 85-year-old male with known cholelithiasis complicated by prior cholecystitis presented with a 2-day history of generalized abdominal pain. Computed tomography (CT) showed fistulisation between the gallbladder and hepatic flexure. Follow-up CT with rectal contrast showed lack of contrast beyond an impacted gallstone in the descending colon (Figure 1A, 1B). The patient was deemed a poor surgical candidate thus endoscopic gallstone extraction was attempted. With a pediatric colonoscope, the 41mm x 51mm gallstone was visualized 70cm from anal verge (1C). The stone was too large to be extracted en-block with snare or basket. Attempts to cut the stone at its surface with a polypectomy snare and other tools were unsuccessful because of the roundness and smoothness of the stone. Although we could chip away at the surface, we were unable to break the seal of the stone against the colon mucosa. We found the most effective method was tunneling through the stone’s centre using a closed rat-tooth forceps, then angling the tip of the scope and pulling the scope back to break off fragments from within. A polypectomy snare was used to further breakup larger fragments to prevent repeat impaction (1D). There was underlying diverticular disease and mild ischemic changes to the mucosa but no stricture. The patient did well post-procedure and was able to tolerate oral intake, pass flatus, and pass bowel movements. He was discharged 3 days later.
A recent systematic review found a total of 38 cases of gallstone obstruction of the colon. Majority of patients (73.6%) ultimately required surgical intervention. Overall mortality is 13.1%.

Conclusions
Gallstone impaction in the colon is uncommon with successful endoscopic treatment seldomly described. This report describes a rare complication of gallstone disease that was successfully treated with widely available endoscopic tools.

Funding Agencies
None
A228 A FERMENTABLE FIBRE FREE DIET ACCELERATES SPONTANEOUS COLITIS DEVELOPMENT AND ALTERS THE GUT MICROBIOME IN MUC2-/- MICE
Authors: Healey G R , Schick A , Jacobson K , Vallance B 
Published: February 2022

Abstract

Background
A key feature of ulcerative colitis (UC) is a defective colonic mucus layer. As Muc2-/- mice lack intestinal mucus, they’re often used to model UC. In these mice, luminal bacteria translocate from the gut lumen, triggering spontaneous colitis by 12–16 weeks of age. Notably, mucus defects are also seen in wildtype mice fed a fermentable fibre free (FF-free) diet. Aside from thinner mucus, FF-free fed mice show increased susceptibility to bacterial infections and a microbiome shift from fibre-utilizing to mucus-degrading bacteria. Indeed, a recent clinical study found that a microbiome shift towards proteolytic bacteria preceded clinical diagnosis of UC

Aims
To determine whether feeding newly weaned Muc2-/- mice a FF-free versus chow or inulin-enriched diet leads to
- more rapid development of spontaneous colitis
- shifts in the gut microbiota towards protein fermentation

Methods
Newly weaned Muc2-/- mice (3–4 weeks old) were fed 1 of 3 diets: 1) usual chow (Chow; 14.7% fibre mix), 2) FF-free (10% cellulose – poorly fermented) and 3) inulin-enriched (IN; same nutritional content as FF-free, with 10% inulin instead of cellulose). Body weight, diet intake and disease activity were monitored daily. By day 10, mice in the FF-free group developed severe colitis requiring euthanization. At this time, cecal contents (short-chain fatty acid [SCFA] analysis) and colonic tissue from all mice were collected for alcian blue/PAS staining and histopathological scoring. Stool was collected for 16S rRNA sequencing

Results
FF-free fed mice consumed fewer calories (p=0.0073), experienced less body weight gain (p=0.002), had colonic shortening (p&lt;0.0001) and higher disease activity scores (p&lt;0.0001) than mice fed the IN diet. Histopathological scores were higher in FF-free versus Chow (p&lt;0.0001) and IN (p&lt;0.0001) fed mice. Goblet cell mucin staining was reduced in FF-free compared to Chow and IN fed mice. Beta-diversity analysis showed clear differences in microbiome composition between groups. Acetate, product of fibre fermentation, was higher in the Chow (p&lt;0.0001) and IN (p=0.0195) groups whereas branched-chain fatty acids (BCFA), product of protein fermentation, was higher in the FF-free group (p&lt;0.0001)

Conclusions
Spontaneous colitis development in FF-free fed Muc2-/- mice was observed within 10 days (5–6 weeks old) of weaning whereas Chow or IN fed mice showed minimal to no signs of colitis, respectively. A diet devoid of fibre also led to less mucin staining and a gut microbiome shift that favoured BCFA over SCFA production, suggesting the microbiota of FF-free fed Muc2-/- mice are targeting mucosal proteins concurrent with disease exacerbation. These findings support future studies examining whether consumption of low fibre diets in UC patients worsen disease outcomes whereas diets rich in fibre and/or inulin prove beneficial

Funding Agencies
CCC, CIHRMSFHR Trainee Award, CH.I.L.D foundation
A232 TUFT CELLS COORDINATE RAPID EXPULSION OF THE TAPEWORM H. DIMINUTA BUT ARE NOT REQUIRED FOR ENHANCED IMMUNITY AGAINST THE NEMATODE, H. POLYGYRUS, IN MICE PREVIOUSLY INFECTED WITH H. DIMINUTA
Authors: Rajeev S , Leon-Coria A , Wang A , Finney C , Mckay D M 
Published: February 2022

Abstract

Background
The tuft cell is an important sentinel that monitors the gut lumen and coordinates immunity against parasitic nematodes. We showed small intestinal tuft cell hyperplasia 11 days post-infection (dpi.) with the tapeworm Hymenolepis diminuta: a time when the parasite is no longer present in murine hosts. This may be a way by which the host protects itself from subsequent helminth-infections, a common phenomenon in parasite-endemic world regions. We test this supposition using Pou2f3-/- mice that lack tuft cells.

Aims
To test the hypothesis that tuft cells are important in the anti-worm response in H. diminuta ( H.d.)-infected mice subsequently infected with the nematode parasite Heligosomoides polygyrus ( H.p.).

Methods
Male C57BL6 and Pou2f3-/- mice (8–12 weeks) were infected with 5 H.d. cysticercoids ± 200 H.p. larvae at 10 dpi with H. diminuta (non H.p. mice - control). Upon necropsy at 24 dpi H. diminuta (i.e. 14 dpi H.p. in co-infected mice), both worms were ennumerated in small intestinal washings, H.p. granulomas examined and fecal egg counts performed. Small intestinal segments were stained for tuft (DCLK1+) and goblet cells (PAS+). As a surrogate of successful infection, IL-4 and IL-10 were measured in supernatants from concanavalin-A treated splenocytes.

Results
Wild-type (WT) mice expel H. diminuta by 11 dpi and this was delayed in Pou2f3-/-mice, with worms readily detectable at 14 dpi and absent by 21 dpi. Despite the delayed expulsion, both WT and Pou2f3-/- mice showed increased splenic production of IL-4 and IL-10; however, unlike WT mice, H. diminuta-infected Pou2f3-/- mice show no increase in jejunal goblet cell numbers. Mice infected with H. diminuta displayed a degree of increased resistance to H.p.-infection defined by reduced worm and egg burdens, and increased granuloma formation in comparison to H.p.-only infected animals. In this sequential co-infection model, there were no significant differences between WT and Pou2f3-/- mice in the response to H.p.

Conclusions
The absence of tuft cells slows expulsion of H. diminuta from its non-permissive mouse host and correlates with diminished goblet cell hyperplasia. Hypothesizing that H. diminuta-evoked tuft cell hyperplasia would enhance the immune response to a subsequent infection with an unrelated nematode parasite proved incorrect. While H. diminuta-infected mice were partially protected from H.p., response was similar in WT and Pou2f3-/- mice. Thus tuft cells are important in worm detection: yet, our co-infection data suggests that other events initiated by the primary worm infection impact the outcome of subsequent infection with a different helminth and tuft cells have a limited, if any, role to play in this helminth-host-helminth interaction.

Funding Agencies
CIHRNSERC, Eye’s High International doctoral scholarship
A256 SURVEILLANCE OF SMALL, NON-FUNCTIONING, ASYMPTOMATIC PANCREATIC NEUROENDOCRINE TUMORS: THE BRITISH COLUMBIA EXPERIENCE
Authors: Jiang S X , Towfighi S , Owen D , Tomaszewski M , Harris A , Donnellan F 
Published: February 2022

Abstract

Background
Expert consensus surrounding surveillance for small, non-functioning, asymptomatic pancreatic neuroendocrine tumors (PNETs) remains conflicting. Recent observational studies have shown that surveillance is a safe strategy while large database studies show superior overall survival with surgical resection.

Aims
To describe the growth of small (&lt;2cm), non-functioning, asymptomatic PNETs undergoing surveillance at a tertiary hospital in British Columbia.

Methods
We conducted a retrospective case series of patients with biopsy-proven, non-functioning, asymptomatic PNETs which were &lt;2cm by RECIST criteria at diagnosis, who were followed through active surveillance at Vancouver General Hospital, British Columbia from February 1, 2011-February 1, 2021. Patients were included if serial imaging, whether by endoscopic ultrasound or cross-sectional imaging, was available for a minimum of 24 months.

Results
Of the 57 patients with pathology-proven PNETs that were identified, 14 cases were included after excluding those with resection within 1 year (n=17), lost to follow up (n=13), metastatic disease (n=6), size greater than 2cm at diagnosis (n=4), and with concurrent cancer (n=3). Included patients were predominantly female (n=10, 71%), Caucasian (n=8, 57%), and had a mean Charlson comorbidity index of 3.14. Mean PNET size at diagnosis was 12mm with standard deviation of 4.26mm. Tumors were located in the pancreatic head (n=4, 29%), body (n=6, 42%), and tail (n=4, 29%). Of 8 patients who had Ki67 stains, all were &lt;3%, and of 11 patients with mitotic index, all had &lt;2 mitotic figures. As such, of the 8 patients with available WHO grading, all were grade 1. The average follow-up was 49.6 months with an average tumor growth of 0.82mm per year. When grouping these tumors by growth, 9 (62%) tumors exhibited no growth, 2 tumors grew &lt;1mm per year, 2 tumors grew 1-1.5mm per year, and 1 tumor grew 7.7mm per year. Two cases (14%) of PNETs underwent surgical resection due to size surpassing 2 cm. No patients undergoing surveillance developed metastatic disease.

Conclusions
To our knowledge, we have performed the first Canadian series of small, low-grade PNETS and demonstrated that active surveillance is a safe strategy with most tumors exhibiting no growth of several years. Of the subset of PNETs which demonstrate progression, the preceding surveillance strategy did not disadvantage patients in terms of progression to metastases and allowed for delay of potentially morbid surgery. Further research with prospective studies and larger samples should be conducted.

Funding Agencies
CAG
Ability of Infrascanner 2000 to predict post-traumatic cranial hemorrhage volume in low-resource settings: a protocol for a multi-center prospective, observational study
Authors: Fernandez Laura L , Griswold Dylan P , Aristizabal Sarita , Sanchez Diana M , Rubiano Andres M 
Published: February 2022

Abstract
Low- and middle-income countries experience three times more traumatic brain injury (TBI) cases when compared with their high-income country counterparts. The quality of care patients receive in the prehospital setting and emergency department settings are highly variable and often dependent on computed tomography (CT) availability. The implementation of a handheld device that is able to reliably diagnose intracranial hemorrhage (ICrH) in TBI patients is needed in these settings where CT is unavailable. The Infrascanner has shown promise to detect intracranial bleeds in patients with moderate TBI. We aim to determine the correlation between the coefficient provided by the Infrascanner compared to the post-traumatic supratentorial hemorrhagic collections volume in patients with surgical indication in differente trauma centers. This is a multi-center prospective observational study that will be carried out in three trauma centers in Colombia, Guatemala and Pakistan. We calculated a sample size of eighty-six patients with mild, moderate or severe TBI ≥ 15 years old who have a supratentorial hemorrhage abnormality that requires neurosurgical intervention. The Infrascanner’s ability to detect IChR in patients with surgical indications associated to hemorrhage volume when compared with CT is the primary outcome measure. Secondary outcome measure is the correlation of the mean of the six Infrascanner measurement values compared with volume of ICrH as measured from the six manual head CT segmentation measurements. ICrH volume correlation and agreement will be evaluated by the Pearson coefficient and Bland-Altman analysis, and a linear regression analysis will be performed in order to predict IChR from the Infrascanner measurement.