bluuebunny/crossref_metadata_2025_split huggingface dataset:
A37 ENTERIC MICROBIOTA CONTRIBUTE TO BEHAVIORAL ALTERATIONS OBSERVED IN MICE WITH COLITIS
Authors: Vicentini F , Griffin L , Keenan C , Cavin J , Nieves K , Hirota S A , Sharkey K A 
Published: February 2020

Abstract

Background
The enteric microbiota has been recognized as an essential regulator of both gut and brain physiology, a complex interaction generally termed the microbiota-gut-brain axis. Disturbances to gastrointestinal physiology lead to alterations in the composition of the enteric microbiota, whereas dysbiosis can also contribute to pathophysiology. Inflammatory bowel diseases (IBD) are chronic, relapsing inflammatory conditions of the gastrointestinal tract, associated with microbial dysbiosis. Interestingly, IBD patients exhibit an increased incidence of mental illness (i.e. anxiety and depression), often termed “sickness behavior”, even during the remitting phase of their disease. Nevertheless, it is unclear if alterations in the enteric microbiota associated with IBD are responsible for the observed modification in brain function and behavior. Here, we hypothesized that sickness behavior is driven by alterations in microbial composition, which occur in the context of intestinal inflammation.

Aims
We sought to determine whether transfer of the microbiota from colitic mice, exhibiting sickness behaviour, into healthy counterparts would induce behavioral changes.

Methods
Male mice (C57Bl/6J; 8 weeks old) were used in all experiments. Colitis was induced by administration of 2.5% dextran sodium sulfate (DSS) in the drinking water for 5 days. Colonic inflammation was assessed by measuring fecal lipocalin-2 and the expression of pro-inflammatory mediators via qPCR. Cecal matter from donor mice (control or DSS treated) were collected for fecal microbiota transplant (FMT). FMT was performed via oral gavage in antibiotic-treated recipient mice. Gut bacteria were evaluated by 16S rRNA sequencing in cecal samples. Anxiety- and depression-like behavior were assessed by elevated plus maze and tail suspension test, respectively.

Results
DSS-treated mice exhibited clinical disease, reflected by body weight loss, increased fecal lipocalin-2 and elevated colonic pro-inflammatory cytokine transcripts. An increase in anxiety-like behavior was observed in mice with colitis, although no alterations in depression-like behavior were detected. Colitic mice exhibited a unique microbial community. Transferring cecal material from colitic mice into recipient, antibiotic-treated mice, recapitulated alterations in behavior seen in colitic donors, as shown by increased anxiety-like behavior and unexpectedly, increased depression-like behavior. These behavioral changes occurred in the absence of colonic or brain inflammation in the recipient mice, but were associated with changes in stress-related gene expression (i.e. Crh).

Conclusions
Colitis-associated sickness behavior can be transmitted to antibiotic-treated recipient mice via FMT, which occurs in the absence of overt intestinal or brain inflammation.

Funding Agencies
CIHRNational Council for Scientific and Technological Development (CNPq-Brazil)
A41 LOSS OF SATB2 EXPRESSION IN COLORECTAL CANCER IS ASSOCIATED WITH DURATION OF INFLAMMATORY BOWEL DISEASE
Authors: Atin J , Hernandez-Rocha C , Borowski K , Stempak J , Smith M , Conner J R , Silverberg M 
Published: February 2020

Abstract

Background
Patients with inflammatory bowel disease (IBD) are at higher risk for developing colitis-associated colorectal cancer (CAC). Clinical and endoscopic features are used to stratify the risk of CAC, but new biomarkers are necessary to improve this stratification. Recent studies have shown that loss of expression of special AT-rich sequence binding protein 2 (SATB2) is frequent in CAC compared to sporadic colorectal cancer and this SATB2 status is found in pre-cancerous dysplastic lesions as well. However, the relationship of known clinical risk factors for CAC and loss of SATB2 has not been explored.

Aims
To assess the association of loss of SATB2 expression in CAC with clinical characteristics of IBD.

Methods
Patients with a known diagnosis of ileocolonic or colonic Crohn’s disease (CD), ulcerative colitis (UC), or IBD unclassified (IBDU) who underwent colectomy between October 2010 and December 2017 for CAC were included. SATB2 expression in neoplastic tissue was evaluated using immunohistochemistry (IHC), where less than 5% of tumor cells showing staining was considered loss of SATB2. Tumor grade, P53 and mismatch repair (MMR) status were assessed as well. Available clinical data such as sex, smoking status, IBD diagnosis (CD, UC or IBDU), age at IBD diagnosis, duration of IBD, extent of colitis and previous medications were collected. We used a generalized linear model to assess the association between these biomarkers and clinical data.

Results
A total of 58 patients with mean age at CAC diagnosis of 50.3 ±13 years, 27 (46%) females were analyzed. Mean IBD duration was 17.6 ±10 years and 22 (37.9%), 34 (58.6%) and 2 (3.4%) were CD, UC and IBDU, respectively. Thirty-two (55.2%) CACs had loss of SATB2 expression. There was no association between age at CAC diagnosis or grade of the tumor and loss of SATB2. However, longer duration of IBD (21.2 ± 9 years vs 13.7 ± 9 years, p = 0.01) was significantly associated with loss of SATB2. There was no association between SATB2 status and other explored clinical or endoscopic variables. Tumors with P53 mutation were associated with a younger age at diagnosis of CAC (47.2 ±13 vs 55.0 ±12 years, p = 0.03), but no other associations of this marker or MMR with clinical or endoscopic variables of IBD were found.

Conclusions
Loss of SATB2 expression is significantly associated with IBD duration, a well-known risk factor for CAC. This association with duration of IBD could denote an effect of longer chronic inflammation on SATB2 status. Given the previously reported association of loss of expression of SATB2 with pre-cancerous lesions in IBD patients, this could be a potential biomarker for risk of CAC.

Funding Agencies
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
A44 NOVEL AND HIGHLY SENSITIVE FLOW CYTOMETRIC BASED METHOD FOR CONTINUOUS TRACKING OF INTESTINAL PERMEABILTIY
Authors: Tsai K , Ma C , Crowley S M , Priatel J , Vallance B 
Published: February 2020

Abstract

Background
Inflammatory bowel diseases (IBD) are chronic, inflammatory conditions of the intestinal tract. In addition to a complex mixture of genetic, and environmental factors, increased intestinal permeability is also thought to be involved. Despite its diagnostic importance, there is no reliable yet minimally invasive way to measure intestinal permeability in patients and animal models. Currently, most assays involve the detection of orally given sugar molecules in either the urine (MLR method) or the plasma (FITC-dextran). These methods offer only limited accuracy, and do not allow continual tracking of intestinal permeability within the same animal due to the requirement of euthanization. Herein, we describe a novel cytometric-based method using an ingested dietary protein (ovalbumin (OVA)) and flow cytometry. We show our method is reliable, highly sensitive, minimally invasive and allows for the continuous tracking of intestinal permeability within the same individual using small blood volumes.

Aims
To compare the utility of our bead-based method of intestinal permeability measurement to the FITC-Dextran method.

Methods
Wildtype (WT) C57BL/6 mice, and mucin 2-deficient (Muc2-/-) mice (known to suffer a leaky gut) at baseline, or mice given chemical or infection-induced colitis were gavaged with a solution containing OVA protein and FITC-Dextran. After 6 hours, mice were euthanized to collect plasma for spectrophotometry (FITC-Dextran), or for flow cytometry (bead-based ELISA) analyses.

Results
We found that both OVA and FITC-dextran were detectable in plasma samples of the Muc2-/- mice, but not the WT mice, 6 hours after oral co-administration, however the bead-based method produced more consistent readings. Immunostaining of tissue sections with the same antibodies also showed that OVA can readily diffuse through the gut epithelium of Muc2-/- mice but not the WT mice, validating the specificity of the antibodies. We also tested our assay on WT mice undergoing dextran sodium sulfate (DSS) colitis, or infected with Citrobacter rodentium. We found that our method could detect statically significant changes in intestinal permeability 2 to 3 days earlier than the FITC-dextran method, while providing greatly reduced variability between technical repeats. More importantly, we were able to use a small volume (5 μL) of whole blood collected via tail poke, to measure intestinal permeability without requiring euthanization of the mice. This allowed the continuous tracking of permeability changes within the same animal.

Conclusions
We conclude that the bead-based method is more sensitive and reliable than the FITC-Dextran method as tested in several murine colitis models. More importantly, we showed that the bead-based method allows continual tracking of intestinal permeability within the same animal, enabling time course measurements.

Funding Agencies
CAG, CCC, CIHR, NRCBC Children’s Research Institute
A46 THE INFLAMMATORY CASPASES COORDINATE MUCOSAL RESTRICTION OF SALMONELLA THROUGH THE EPITHELIAL-INTRINSIC INFLAMMASOME AND IL-22 DRIVEN MUCIN SECRETION
Authors: Crowley S M , Allaire J M , Han X , Graef F A , Stahl M , Knodler L , Vallance B 
Published: February 2020

Abstract

Background
Intestinal epithelial cells (IECs) are located at the interface between the gut lumen and the underlying mucosal defense system. Here, they play a central role in the coordination of intestinal homeostasis, tempering pro-inflammatory responses but remaining rapidly responsive to noxious stimuli such as enteric pathogens. One early response mechanism by which IECs engage in immune defense is through the activation of the inflammasome which mobilizes the inflammatory caspases; caspase-1 and -11.

Aims
Here, we investigated the role of the inflammasome in overall mucosal defense against the enteric pathogen Salmonella enterica serovar Typhimurium.

Methods
Streptomycin-pretreated C57BL/6 (wildtype), Casp1/11 deficient (−/−), Casp1−/− and Casp11−/− mice were orally infected with Salmonella and burdens determined in intestinal tissues at 18h post infection (p.i.).

Results
Increased pathogen loads were observed for all caspase-deficient mice compared to wildtype, which correlated with increased IEC intracellular Salmonella burdens. Interestingly, despite increased bacterial loads, pathology scores for all inflammatory caspase mice were decreased, especially with regard to ‘IEC damage’ and ‘goblet cell loss’.
To determine if the increased burdens were due to the loss of IEC-intrinsic inflammasomes, enteroid monolayers were derived and infected with Salmonella. This revealed significantly increased intracellular burdens in caspase-deficient monolayers as compared to wildtype, in concert with a marked decrease in IEC shedding and cell death. Peak inflammatory caspase activity was displayed in shedding wildtype IECs, suggesting the IEC-intrinsic inflammasome restricts Salmonella infection through infected IEC expulsion.
The role of inflammasome signaling in acute mucosal defense was also examined. Wildtype tissue demonstrated a dramatic increase in mucus thickness (as evaluated by Muc2 immunostaining) and antimicrobial Reg3γ and β lectin transcript levels compared to caspase-deficient mice. Mucin release and Reg3 induction has been previously linked to IL-22, therefore we measured IL-22 expression and observed increased secretion in infected wildtype mice compared to Casp1/11−/−. This correlated with increased cecal infiltration of IL-22 producing ILC3 and NK T-cells. When infected mice were treated with IL-22 neutralizing antibody, this increased Salmonella burdens and decreased infection-induced mucus secretion, while no differences were observed in Casp1/11−/− treated with neutralizing antibody or isotype control.

Conclusions
Therefore the intestinal epithelium utilizes inflammasome signaling to coordinate multiple layers of innate defense at the gut mucosal surface to ultimately restrict enteric pathogen infections and their systemic spread.

Funding Agencies
CCC, CIHR, NRCUBC
A54 DELTA OPIOID RECEPTOR SIGNALING MEDIATES OPIOID INDUCED TOLERANCE AND HYPERALGESIA IN COLONIC SENSORY NERVES
Authors: Jaramillo Polanco J O , Lopez Lopez C D , Yu Y , Reed D E , Lomax A E , Vanner S 
Published: February 2020

Abstract

Background
While opioid drugs are widely used for treating abdominal pain, prolonged exposure to opioids can induce tolerance and paradoxically increase pain. We previously showed in colonic afferent nerves that chronic morphine treatment causes tolerance and paradoxical hyperalgesia, however the mechanisms are unknown.

Aims
To evaluate the role of delta opioid receptor (DOR) signaling in opioid induced tolerance and hyperalgesia in colonic nerves during chronic morphine exposure.

Methods
C57BL/6 mice were injected (i.p.) twice daily for 7 days with escalating doses of morphine (10, 20, 30 mg/kg for the first 3 days, then 40mg/kg on 4th to 7th day); a subset of mice were also injected with 2.5 mg/kg naltrindole (NTI), a DOR antagonist. The analgesic response in vivo was monitored daily using the tail-flick test. To assess the effect of chronic morphine exposure, mice were euthanized on day 8, and the dorsal root ganglia (DRGs) and colons were harvested. Isolated DRG neurons were incubated with 1μM morphine (30 min) and neuronal excitability was determined by measuring the rheobase (amount of current required to elicit an action potential) using perforated patch clamp. To assess changes in colonic afferent nerve excitability, ex vivo afferent nerve recordings were obtained from flat-sheet colon preparations to determine the effects of 1μM morphine (10 min perfusion) on mechanosensitivity by probing with 1g von Frey hair.

Results
The tail flick test showed that the DOR antagonist NTI inhibited (30%) the maximal antinociceptive effect of morphine and reduced morphine tolerance. In patch clamp recordings, 1μM morphine paradoxically increased the excitability of small DRG neurons from morphine mice (rheobase decreased 28%; p&lt;0.05, 2-way ANOVA), whereas this excitatory effect was absent on neurons from NTI+morphine mice. Acute application of 1μM morphine had no effect on afferent nerve responses to probing in morphine mice (14.9 vs 16.7 Hz; p=ns, paired t test, n=15) whereas it inhibited the afferent nerve response to probing in NTI+morphine mice (15.2 vs 9.9 Hz; p&lt;0.001, paired t test, n=16). Furthermore, most single units from morphine mice had an increased response to probing following acute morphine application (7/15 vs 2/16 units excited), whereas most units form NTI-morphine mice were inhibited (14/16 vs. 3/15 units inhibited, P&lt;0.001, Chi-square).

Conclusions
These findings suggest that DOR signaling plays a significant role in the development of opioid tolerance and hyperalgesia in colonic afferent nerves induced by chronic morphine treatment. Thus, antagonists of DOR may help to mitigate these side effects induced by opioids.

Funding Agencies
CCC
A57 VALPROATE INDUCED DRESS SYNDROME CAUSING MIXED LIVER INJURY
Authors: Schneider R , Verstegen R , Hulst J , Ito S , Ng V 
Published: February 2020

Abstract

Background
Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome occurs with 1 in every 1,000 to 10,000 drug exposures and has a mortality rate of up to 10%. It is one mechanism by which medications can induce liver injury with elevated liver enzymes seen in the majority of cases. In children, aromatic anticonvulsants are the drugs most commonly associated with DRESS syndrome. Valproate, a non-aromatic anti-epileptic, is not known to have a heightened risk of hypersensitivity syndromes and is often the anti-epileptic of choice in patients who develop hypersensitivity syndromes from other anti-epileptics. Valproate hepatotoxicity is normally caused by its inhibition of fatty acid transport and mitochondrial β-oxidation; vanishing bile duct syndrome is also reported.

Aims
We present a case, to the best of our knowledge the first in paediatrics, in which valproate causes DRESS syndrome and a secondary, predominantly cholestatic, liver injury.

Methods
Literature review and case report.

Results
A previously healthy 14-year-old girl was diagnosed with new-onset seizures and started on valproate. Three weeks later, she developed a pruritic exanthem. Despite discontinuing her valproate, the rash persisted and she developed fever and jaundice. She was admitted to the ICU at the Hospital for Sick Children with a diagnosis of DRESS syndrome (RegiSCAR DRESS score 7) for treatment with IV steroids. At admission, she had a skin eruption, fever, leukocytosis (22.86 x109/L), eosinophilia (1.03x109/L), atypical lymphocytes (1.62 x109/L), lymphadenopathy, and internal organ involvement (BiliC 138, GGT 501, INR 1.3, ALT 543, AST 370, Crt 109). Of note, her EBV PCR was positive. By discharge, her rash improved and kidney function normalized. Her cholestasis persisted, despite improvement in her transaminases and eosinophilia (BiliC 163, INR 1.0, GGT 338, ALT 506, AST 220, Eos 0.98x109/L). She was discharged home on an oral steroid wean, ursodeoxycholic acid, levocarnitine, and levetiracetam. Upon reaching a daily dose of 20mg of prednisone, her rash and pruritus worsened, she had lost 7kg, and she was readmitted for IV steroids. Her rash improved within 4 days and she was discharged on a slower steroid taper, with the addition of cholestyramine and insulin for steroid induced diabetes. At present (2 ½ months after diagnosis), she continues her oral steroids and has persistent liver injury and pruritus.

Conclusions
We report the first paediatric case of valproate induced DRESS syndrome causing a significant cholestatic presentation with otherwise preserved liver synthetic function. The prolonged cholestasis and pruritus may be a result of the natural course of DRESS syndrome, EBV reactivation/infection, or polypharmacy. Early recognition of DRESS syndrome as a mechanism of valproate induced liver injury in children is essential for earlier diagnosis and initiation of targeted therapy.

Funding Agencies
None
A70 ASSOCIATION BETWEEN PROTON PUMP INHIBITOR USE IN HOSPITALIZED CIRRHOTICS AND DEVELOPMENT OF HEPATIC ENCEPHALOPATHY AND SPONTANEOUS BACTERIAL PERITONITIS
Authors: Tan P , Ukos M , Miller C , Lombardi J , Kelly E M 
Published: February 2020

Abstract

Background
Proton pump inhibitors (PPI) are commonly prescribed medications which are indicated in various different gastrointestinal (GI) diseases, including peptic ulcer disease, gastroesophageal reflux disorder and upper GI bleeding. There is some evidence to suggest that PPI use in cirrhosis may predispose to the development of hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP), albeit with some controversy.

Aims
We aim to conduct a retrospective epidemiological analysis of the association between PPI use in hospitalized patients with cirrhosis, and prevalence of HE and SBP.

Methods
This was a retrospective cohort study of 600 adult patients (mean age 61.4 (SD=12.2)) admitted the Ottawa Hospital between January 1, 2011 and December 31, 2015 with cirrhosis. A chart review was conducted and relevant information extracted.

Results
Average MELD-Na on admission was 16.2 (sd=6.7). 14.8% of patients had a history of HE, 5.0% SBP, 7.8% with history of hepatocellular carcinoma and 1.0% with history of hepatorenal syndrome. 28.5% of patients had a history of varices, of which 11.0% had previous variceal bleeding. 69.3% of patients were on a PPI during their hospitalization. Not surprisingly, patients admitted with variceal bleeding were more likely to be exposed to PPI in hospital (97.2% vs 63.2%, p&lt;0.01) Patients with a diagnosis of cirrhosis prior to index admission were more likely to be on a PPI in hospital (p=0.001) and on discharge (p=0.001). Patients with ascites were less likely to be on a PPI than those without ascites (64.1% vs 77.6%, p&lt;0.01). There was no significant correlation between in hospital PPI use and MELD score (p=0.42). Amongst patients on PPI in hospital, 85.9% remained on a PPI at discharge. Although numerically greater, no statistically significant differences were observed in terms of prevalence of HE (21.3% in patients on PPI vs 8.3% in those not on PPI (p=0.37)), nor SBP (5.7% on PPI vs. 3.7% in those not on PPI (p=0.29)).

Conclusions
We did not observe a significant difference in HE and SBP among this cohort of cirrhotic patients by in-hospital PPI use. We did however note significantly higher PPI use in patients with previous diagnosis of cirrhosis as compared to those who were newly diagnosed, as well as those whose admissions were related to bleeding. Patients with ascites had lower prevalence of PPI use. Prescribing patterns for PPIs in patients with cirrhosis warrant further attention, including clinical utility and longer-term risks and benefits of this therapy.

Funding Agencies
None