bluuebunny/crossref_metadata_2025_split huggingface dataset:
A36 THE ROLE OF MICROBIAL INDOLE METABOLITES IN CONTROLLING INFLAMMATORY RESPONSES AND HEALING IN RESPONSE TO DSS-INDUCED COLITIS
Authors: Nieves K , Flannigan K L , Alston L , Thomson C , McCoy K , Mani S , Hirota S A 
Published: February 2020

Abstract

Background
Failure to resolve inflammation is often associate with the complications of Crohn’s Disease (CD). The pregnane X receptor (PXR), a xenobiotic receptor, is recognized for its role in suppressing inflammation and has recently been shown to influence fibrogenesis in the liver. In the intestine, PXR-signaling can be influenced by the microbial tryptophan metabolite indole-3- propionic acid (IPA), which can modulate intestinal inflammation, in turn influencing fibrogenesis, resolution and healing. This suggests that the gut microbiota could modulate mucosal homeostasis and resolution of inflammation via microbial metabolites

Aims
To understand and characterize the interplay between microbial complexity and the regulation of host inflammatory and healing responses, specifically focusing on the PXR and its microbial metabolite ligand IPA.

Methods
Intestinal inflammation was induced using DSS (1%, 1.5%, 2% and 3.5%) for 5 days followed by healing for 25 days in C57Bl/6 stably derived moderately diverse mouse microbiota 2 (sDMDMm2) colonized gnotobiotic and C57Bl/6 specific pathogen free (SPF) mice. Inflammation, architectural changes and fibrosis were assessed using Haemotoxylin and Eosin and Masson-Trichrome histological stains. Weight was recorded daily for the first 10 days and every other day after for 25 days, for a total of 30 days. Fecal lipocalin was quantified in samples collected throughout the study to assess inflammation. Innate immune cell influx was measured by flow cytometry, and the microbiota assessed via 16S rRNA sequencing.

Results
The gnotobiotic sDMDMm2 mice were exquisitely sensitive to DSS-induced colitis, exhibiting significantly increased mortality and morbidity at 2% and 3.5% w/v DSS compared to the SPF group. To elicit the same degree of disease to assess recovery, sDMDMm2 mice were exposed to 1.5% DSS and SPF mice to 3.5% DSS. Following 25 days recovery, sDMDMm2 colonized mice showed increased levels of fecal lipocalin 2, as compared to the SPF mice. DSS-treated sDMDMm2 mice supplemented with IPA during their recovery presented lower levels of fecal lipocalin, similar to colitic SPF mice. IPA supplemented sDMDMm2 mice also exhibited greater overall survival, with no significant differences in neutrophil count compared to mice given H20 during recovery.

Conclusions
A model system with a less complex microbiota (sDMDMm2) has a higher susceptibility to acute inflammation and a diminished capacity to resolve said inflammation. Addition of the microbial metabolite IPA normalized the recovery of the sDMDMm2 colonized mice, to a response indistinguishable from SPF mice, while also increasing survival. These data highlight the importance of microbial complexity in the regulation of intestinal mucosal homeostasis.

Funding Agencies
CAG, CCC, CIHR
A45 INFLAMMATION AND INTESTINAL PERMEABILITY IN PEDIATRIC SHORT BOWEL SYNDROME
Authors: Dowhaniuk J K , Chorlton S , Teskey G , Loukov D , Verschoor C , Owens J , Clause R , Pernica J , Bowdish D , Surette M , Ratcliffe E 
Published: February 2020

Abstract

Background
Both intestinal dysbiosis and central-line associated blood stream infections (CLABSI) have been well documented in children with short bowel syndrome (SBS). Gastrointestinal microbiota prime and regulate mucosal immunity, therefore we hypothesize children with SBS may have longstanding increased intestinal permeability which could lead to mucosal inflammation and predispose to bacteremia.

Aims
We sought to investigate intestinal permeability as well as both intestinal and systemic activation of the inflammatory cascade in children with SBS.

Methods
Two cohorts of children with SBS were consented; with Group 1 including children with SBS requiring central venous catheter (CVC) for parenteral nutrition, and Group 2 including children with SBS without CVC. SBS groups were compared to three control groups including age and sex-matched children with CVC for hematologic disease (Group 3), children without a CVC (Group 4) and healthy adult controls (Group 5). To evaluate intestinal permeability, we quantified circulating bacterial products LPS and MDP through the binding of their respective receptors, TLR4 and NOD2. To determine colonic inflammation, fecal calprotectin was quantified from a single stool sample. Cytokine profiles included IFN-γ, IL-Iβ, IL-8, IL-10, IL-17, TNFα were quantified by Multiplex Immunoassay while gene expression of transcription factors FoxP3+, RORγT, TLR2, and TLR4, were determined by RNA extraction and quantitative PCR.

Results
22 children were recruited in the study (Group 1 n=6, Group 2 n=6, Group 3 n=5, Group 4 n=5) as well as 10 adult control samples (Group 5). The median age of Group 1 was 67 months with a residual small intestine of 26.5cm (IQR 24.7–40) while those in Group 2 were 51 months with a residual small intestine of 55cm (IQR 31.2–89). Circulating bacterial products of LPS and MDP were not different between SBS groups and control children. Serum analysis of cytokine TNFα was significant (p&lt;0.005) however multiple comparator analysis did not identify within group differences. Other cytokines did not differ between groups. Fecal calprotectin levels were not elevated however statistically lower in Group 1 (median 12.8mg/kg; IQR 9.3- 34.9) compared to in Group 2 (median 96mg/kg, IQR 71.6–188.2;) p &lt;0.01. Relative quantification of RNA expression of FoxP3+, RORγT, TLR2, and TLR4 did not differ between groups.

Conclusions
Despite concern of compromised intestinal epithelial barrier function in children with SBS, this study did not detect differences in circulating bacterial products compared to control children as an assessment of intestinal permeability nor increased systemic inflammation. Further research is required to investigate intestinal epithelial barrier function over time and the mechanism of bacteremia in children with SBS.

Funding Agencies
CAGRegional Medical Associates of Hamilton
A47 ENTERIC TUFT CELL HYPERPLASIA FOLLOWING INFECTION WITH THE TAPEWORM HYMENOLEPIS DIMINUTA IS AFFECTED BY NEURONAL BUT NOT BACTERIAL FACTORS
Authors: Rajeev S , Defaye M , Shute A J , Wang A , Wang S J , Altier C , McKay D M 
Published: February 2020

Abstract

Background
Tuft cells are a rare chemosensory population of the intestinal epithelium that detect intestinal parasitic nematodes and release IL-25 to mobilize innate lymphoid type 2 cells (ILC2), which then drive a Th2- dominant nematode expulsion response. Immunocompetent mice develop tuft cell hyperplasia in the small intestine during infection with Hymenolepis diminuta, a non-abrasive lumen dwelling small intestinal cestode parasite. Helminth infections are accompanied by alterations in sensory motor functions of the gut as well as the composition of the microbiota. It is poorly understood if tuft cell hyperplasia is regulated by these immunomodulatory influences.

Aims
To test if mice lacking (1) a functional adaptive immune system, (2) TRPV1+ gut-innervating sensory nerves and (3) a microbiome, display enteric tuft cell hyperplasia following infection with H. diminuta.

Methods
RAG-1-/- (male and female) and germ-free mice (n=3–6) were infected with 5 cysticercoids of H. diminuta and age matched non-infected mice served as control groups. Male C57BL/6j mice were treated with resiniferatoxin (RTX) to ablate TRPV1 +sensory neurons before infection. Mid-jejunum cryostat or paraffin embedded sections immunostained against doublecortin-like kinase -1 (DCLK-1) were blindly scored for tuft cell enumeration at 5–14 days post-infection.

Results
Tuft cell hyperplasia (~10-15-fold increase) was observed in the jejunum of wild-type mice at 11 days post infection with H. diminuta, by which time worms are expelled. Infected RAG-1-/- mice develop tuft cell hyperplasia of lesser magnitude than wild-type mice. Germ-free mice displayed tuft cell hyperplasia and kinetics of worm expulsion that were not different from wild-type mice. RTX-treated mice with confirmed loss of TRPV1+ nerve fibers in the gut and their cell soma in the dorsal root and nodose ganglia, had a greater increase (~2-fold) in tuft cell numbers compared to H. diminuta-only mice at 11 days post-infection.

Conclusions
Knowledge of how the host senses helminths in the gut lumen is central to the host-parasite interaction. Using the H. diminuta-mouse model system we find that tuft cell hyperplasia is largely, but not entirely dependent on adaptive immunity, occurs independent of the gut microbiota, and, intriguingly, TRPV1+ sensory nerves appear to act as a brake on the system, limiting the magnitude of the hyperplasia.

Funding Agencies
CIHRNSERC, Henry Koopman’s Memorial scholarship
A49 CO-INFECTION WITH PARASITIC WORMS ENHANCES THE ABILITY OF SALMONELLA TO COLONIZE THE GUT LUMEN AND DEWORMING RESTORES COLONIZATION RESISTANCE TO SALMONELLA
Authors: Brosschot T P , Lawrence K M , Kennedy M H , FitzPatrick R D , Moeller B E , Han J , Borchers C , Reynolds L A 
Published: February 2020

Abstract

Background
Chronic infections with intestinal helminths occur primarily in world regions where infections with bacterial pathogens are also common. Research so far has shown that helminths can promote bacterial infection, however, the precise mechanisms of this are unknown. Current helminth control strategies involve mass deworming programs, and it is as yet unclear how deworming impacts susceptibility to bacterial infections in helminth-affected areas.

Aims
Our aims were to decipher the mechanistic details by which helminths can promote intestinal bacterial infection, and to determine how deworming affects susceptibility to intestinal colonization by bacterial pathogens.

Methods
Using a mouse model of enteric helminth-bacterial coinfection, we examined how the small intestinal helminth Heligmosomoides polygyrus promotes intestinal colonization by Salmonella enterica serovar Typhimurim. To study the effect of deworming of concurrent Salmonella infection, we treated our helminth-infected mice with the anthelmintic drug Strongid P both before and after Salmonella (co-) infection. To examine whether heightened Salmonella colonization during helminth infection depended on the ability of Salmonella to invade host tissue, we compared the ability of wild-type Salmonella or an invasion-deficient mutant (ΔinvA) to colonize during helminth co-infection.

Results
An ongoing helminth infection resulted in high levels of Salmonella in the small intestine after co-infection, however, when mice were dewormed prior to Salmonella co-infection, they were no longer susceptible to high small intestinal Salmonella burdens. In contrast, when helminth-infected mice are dewormed after Salmonella has already co-colonized, high Salmonella burdens persisted in the small intestine. Further, we found that during helminth co-infection, Salmonella primarily expands in the gut lumen rather than in the small intestinal tissue, and in line with this, a Salmonella invasion mutant was able to colonize the intestine to a similar extent to wild-type Salmonella during helminth infection.

Conclusions
Deworming experiments have revealed that the effects of H. polygyrus on promoting Salmonella colonization in the small intestines depend on the ongoing presence of the helminth. Deworming did not revert bacterial burdens once Salmonella had colonized, suggesting that an ongoing helminth infection reduces colonization resistance to Salmonella infection but was not required for Salmonella to persist after initial colonization by Salmonella. Further, we discovered that Salmonella expansion during helminth infection is independent of bacterial invasion of host tissue.

Funding Agencies
CIHR
A56 THE USE OF HIGH VOLUME PLASMAPHARESIS IN ACUTE LIVER FAILURE
Authors: Tam L , Sy E , Karvellas C J 
Published: February 2020

Abstract

Background
Acute liver failure (ALF) can result in irreversible shock, cerebral herniation or development of multiple organ failure (MOF). One randomized study and a separate case series have demonstrated the safety and potential improvement in transplant-free survival with the use of high volume plasmapheresis (HVP). HVP is defined as an exchange of 8-12L or 15% of ideal body weight with fresh frozen plasma. In ALF, cytokines are responsible for the progression of MOF and HVP removes these cytokines from the systemic circulation. We report a case of implementing HVP in an adult with ALF in the intensive care unit (ICU) at a tertiary care center.

Aims
This case and the associated literature review highlight the value of HVP in ALF.

Methods
Case report and literature review.

Results
We report a case of a 34-year-old male who presented in ALF secondary to unknown ingestion. He was admitted to the ICU for worsening transaminitis, coagulopathy, hepatic encephalopathy, renal failure and hemodynamic instability which required vasopressor and ventilatory support. A discussion was made with hepatologists at a regional transplant center for potential consideration of either transplant or Molecular Adsorbent Recirculating System (MARS) therapy. However, the patient was too hemodynamically unstable for transport and also began to develop signs of cerebral edema. As a result, they recommended a trial of high volume plasmapheresis. Shortly after initiation, the patient’s hemodynamic, respiratory, and biochemical parameters began to improve, resulting in less vasopressor and ventilator support (Table 1). Despite improvements in these parameters, the patient’s cerebral edema continued to worsen and an electroencephalogram showed signs of a very low likelihood of functional neurological recovery. Given the overall picture, the patient’s spouse decided to withdraw care.

Conclusions
Presently, liver transplantation remains the only definitive management strategy for ALF patients, but many do not survive to liver transplant or are not candidates for medical or psychosocial reasons such as with this case. As a result, this case demonstrates the potential benefits of conducting HVP in centers without access to MARS or transplantation. However, although HVP did improve certain parameters for this patient, it did not improve overall prognosis. This suggests that prognosis may not improve once a certain threshold of MOF develops. Therefore, in this case and the associated literature review the optimal timing of initiating HVP remains unclear.

Funding Agencies
None
A69 MULTIPLE FUNCTIONAL GASTROINTESTINAL DISORDERS IN JORDANIAN CHILDREN, NATIONWIDE STUDY
Authors: Altamimi E 
Published: February 2020

Abstract

Background
Functional gastrointestinal disorders (FGIDs) are common in children worldwide. Multiple FGIDs might share some etiopathogenesis, which makes finding multiple disorders in a child a possibility.

Aims
Estimate the prevalence of FGIDs in Jordanian children prospectively, whether as a single or combined disorders.

Methods
A prospective, cross-sectional study was conducted in 6 cities in Jordan. Children between the ages of 4–18 were recruited. A validated Arabic language questionnaires based on Rome III criteria were filled by the participants if older than 10 years and by the parents if younger than 10 years.

Results
A total of 1587(79.35%) participants filled the questionnaires. 814 (51.29%) were younger than 10 years. FGIDs was diagnosed in 204 (25.03%) of younger children. In children between (11 and 18), 310 (40%) were diagnosed with FGIDs.
In children (4–10 yrs.) who were diagnosed with FGIDs, 15.5 % had two disorders, while 3% had three or more disorders. The most common combination was aerophobia and functional constipation, comprising 22.58% of combined disorders. In children (11–18 yrs.) with FGIDs, 22.27% had two disorders and 7% had three or more disorders. Interestingly, the most common combination was aerophagia and functional constipation also, representing 34% of the combined cases.

Conclusions
Functional gastrointestinal disorders are common in Jordanian children. Multiple Functional gastrointestinal disorders may coexist. Diagnosis of one disorder should not prevent us from investigating other disorders.

Funding Agencies
None
A72 VARICEAL BLEED & PORTAL HYPERTENSIVE GASTROPATHY IN A NON-CIRRHOTIC PATIENT WITH ISOLATED SPLENOMEGALY
Authors: Hasan S , Dmitriew M , Leonard J 
Published: February 2020

Abstract

Background
Portal hypertension caused by cirrhosis is the most common etiology of esophageal varices. However, abnormalities of the spleno-portal axis in the absence of liver disease may also cause portal hypertension resulting in varices. We report a rare case of esophageal variceal bleed in a non-cirrhotic patient with isolated splenomegaly secondary to chronic G-CSF therapy.

Aims
This report outlines the case of a patient with Cohen Syndrome (CS) who presented with an upper gastrointestinal (GI) bleed in the setting of previously documented splenomegaly and portal hypertension. We expand on the clinical investigations, diagnosis, treatment plan and hospital course of this patient.

Methods
Case report, review of literature.

Results
A 26-year old male with previously diagnosed CS presented with large volume hematemesis and pancytopenia. CS is a rare autosomal recessive disorder. In our patient this manifested with congenital neutropenia, microcephaly, retinal dystrophy and global developmental delay. He required long term G-CSF therapy to manage chronic neutropenia and subsequently developed splenomegaly, a known side effect. The most recent MRI identified stable splenomegaly with a craniocaudal length of 23 cm, normal liver size and no radiographic evidence of cirrhosis. The imaging was also significant for gastroesophageal and splenorenal varices but no ascites or recanalization of the umbilical vein. A recent liver biopsy had shown mild pericellular fibrosis with no active liver disease or cirrhosis. In the past, the patient had declined EGD, therapeutic splenectomy or assessment of hepatic venous pressure gradient through invasive venography. His liver enzymes, bilirubin and albumin had always been within normal limits. The patient had no history of GI bleeding. Previous investigations for hematologic malignancies or myelodysplastic syndrome had been negative. Upon admission, an urgent EGD revealed active variceal bleeding in the esophagus and portal gastropathy. Given the extent of his congenital orofacial abnormalities a variceal band ligator could not be passed for appropriate intervention. The patient was transferred to the Intensive Care Unit and managed with intravenous proton pump inhibitor, octreotide, as well as transfusions of packed red blood cells, platelets and fresh frozen plasma. Within the next 48 hours, the patient underwent successful transjugular intrahepatic portosystemic shunt and CT-guided coil placements for the bleeding varices.

Conclusions
This is a rare case of variceal bleed in a non-cirrhotic patient with portal hypertension from iatrogenic splenomegaly. While there are previous reports of spontaneous splenic rupture secondary to G-CSF therapy we are the first to report variceal bleed as a complication. This is a life-threatening consequence that requires urgent intervention and intensive care.

Funding Agencies
None
A77 FURTHER CARACTERIZATION OF THE 67 KDA LAMININ RECEPTOR (67LR) IN COLORECTAL CANCER CELLS
Authors: Cloutier G , Khalfaoui T , Beaulieu J 
Published: February 2020

Abstract

Background
The 67 kDa laminin receptor (67LR) was the first non-integrin cell surface receptor for laminin isolated on laminin affinity columns from cancer cells in the 1980’s. Initially, 67LR is found as a cytoplasmic precursor of a 37 kDa protein, named 37LR, associated with the small ribosomal subunit. In human cells, 37LR allows the formation of the polyribosome complex and plays a key role in the initiation of translation. The mechanism by which the ribosomal protein becomes the 67LR membrane receptor is still unclear. It is presumed that the process involves post-translational modifications combined with homo or hetero-dimerization with non-associated ribosomal proteins. It has been shown that 37/67LR regulates adhesion and proliferation of normal human intestinal epithelial cells. Interestingly, overexpression of 37/67LR is correlated with aggressiveness and a poor prognosis in a wide variety of cancers.

Aims
The aim of this study was to confirm the overexpression of 37/67LR at the membrane of colorectal cancer cells and to identify its homo or heterodimerization partners.

Methods
To detect the expression of 37/67LR in colorectal cancer we performed an indirect immunofluorescence on tissues from normal and diseased colons. To confirm the presence of 67LR at the membrane of Caco-2 cells we used a cellular fractionation extraction protocol combined with ultracentrifugation and detergent treatment to separate ribosome-containing fractions from the membranes and isolate the membrane associated 67LR. Mass spectrometry analysis to study the molecular identity of 67LR was performed on immunoreactive bands corresponding to 37LR and 67LR.

Results
Immunolocalization of 37/67LR revealed an overexpression in colorectal cancer tissues. Following analysis by western blotting, immunoreactive 67LR protein was found in the soluble fraction after ultracentrifugation at 210,000 x g while 37LR was detected in the insoluble counterpart which was solubilized after treatment with detergent, suggesting that 37LR is associated with the membrane. Mass spectrometry analysis of these fractions indicated that 37LR was not identified in the immunoreactive bands of 67LR in the soluble fraction but identified the 67 kDa elastin binding protein, another 67 kDa cell surface laminin receptor.

Conclusions
These results indicate that 37LR is overexpressed in colorectal adenocarcinoma cells. Further characterization of the receptor by cell fractionation and mass spectrometry indicated that the 67 kDa immunoreactive form is not related to 37LR. Supported by CIHR.

Funding Agencies
CIHR