A199 UTILIZATION OF MUCUS-DERIVED O-GLYCAN SUGARS BY THE PATHOGEN C. RODENTIUM FACILITATE ITS COLONIZATION OF THE MURINE GUT

Background

The ability of enteric pathogens to colonize and expand within the mammalian gastrointestinal (GI) tract is determined by several factors, including the ability to find and acquire nutrients. The thick mucus layer that lines the inner surface of the large intestine is rich in sugars that can serve as nutrient sources for several members of the microbiota. Whether these sugars can also be used by invading bacterial pathogens to colonize the GI tract is still unclear, in particular for the family of attaching and effacing (A/E) bacterial pathogens, including the human diarrheal pathogens EHEC and EPEC.

Aims

To investigate the ability of the murine A/E pathogen Citrobacter rodentium to use mucin-derived sugars as a nutrient source, and the importance of these sugars in the virulence of C. rodentium during in-vivo infection.

Methods

To identify which sugar(s) are required for C. rodentium to colonize and grow in the murine GI tract, we generated mutants lacking single or multiple genes involved in the uptake and catabolism of mucin-derived O-glycan sugars. This was followed by in-vitro growth assays in minimal media supplemented with mucin sugars to investigate the growth properties of C. rodentium and the generated mutants on mucin sugars.

Results

We determined that C. rodentium was able to use three mucin O-glycan sugars: sialic acid, galactose, and N-acetylglucosamine (GlcNAc) as both carbon and nitrogen sources for in-vitro growth. C. rodentium exhibited the maximal growth rate and density on GlcNAc, followed by sialic acid, and finally galactose. A mutant C. rodentium strain carrying a deletion in the nagA gene was unable to grow on both GlcNAc and sialic acid, confirming that the breakdown pathways for these two sugars merge and are processed by shared suite of enzymes. As for galactose, combined deletions in the genes mglB and galP were required to abolish growth on this sugar. Notably, a mutant strain carrying simultaneous deletions in nagA, mglB, and galP was unable to grow on all three mucin sugars, as well as on purified mucin.

Conclusions

Our results demonstrate that intestinal mucin sugars serve as potential nutrient sources for C. rodentium and that C. rodentium can catabolize three of these sugars. Future work will examine whether these sugar pathways contribute to C. rodentium colonization of the murine GI tract.

Funding Agencies

CCC, CIHRCH.I.L.D. Fdn

A158 COMPARING CORTIMENT® AND PREDNISONE IN ULCERTATIVE COLITIS: A POPULATION-BASED STUDY OF OUTCOMES

Background

In August 2016 Cortiment® was approved for use in ulcerative colitis (UC) patients in Canada, but not approved for reimbursement; the Canadian Agency for Drugs and Technology in Health cited no comparable benefit for its use over other approved UC medications. Real-world data comparing Cortiment® to other UC medications is limited, especially during the COVID-19 pandemic where the use of steroids is counter-indicated for COVID-19-related outcomes.

Aims

To examine the comparative risk of hospitalization, surgery, and infection after initiation of Cortiment® or oral corticosteroids among UC patients using real-world data

Methods

Using population-based data from Alberta Canada, two cohorts were compared: 1. Patients dispensed Cortiment® and an ICD diagnostic code for UC [9: 556.X; 10: K51.X] (August 1, 2016 to October 31, 2019); and, 2. Validated (algorithm) UC patients dispensed a >30 day supply or >500mg in 24 hours of prednisone/prednisolone (April 1, 2016 to October 31, 2019). All hospitalizations, IBD-surgery, or infections (i.e., pneumonia, c.diff, sepsis, tuberculosis) that occurred 6 or 12 months from initial medication dispensing were identified. Cox-proportional hazard models, with Hazard Ratios (HR), assessed comparative outcomes. Kaplan-Meier survival curves were created, and Poisson regression (or negative binomial) used to assess the Average Monthly Percentage Change (AMPC) with associated 95% confidence intervals (CI).

Results

We identified 917 Cortiment® and 2,404 Prednisone patients. Over the study period, prednisone dispensing significantly decreased (AMPC:-2.53% [CI:-2.85,-2.21]) while Cortiment® remained stable. Dispensing of Cortiment® significantly decreased the hazard of hospitalization (all types, except surgery) at 12 months as compared to prednisone, and significantly decreased the hazard of an infection at both 6 and 12 months (Table 1, Fig 1).

Conclusions

The use of Cortiment® in a real-world setting is associated with fewer deleterious outcomes, and its use during a pandemic should be preferred, especially when it’s counterpart can exacerbate negative COVID-19-related outcomes.

Table 1

Kaplan-Meier Survival Curves of 1-year Outcomes: A) All Hospitalizations; B) IBD-Related Hospitalizations; C) IBD-Specific Hospitalizations; and, D) Any Infection.

Dashed Line

Cortiment Cohort

Solid Line

Prednisone/Prednisolone Cohort

Funding Agencies

Ferring Pharmaceuticals

A211 INCIDENCE OF PRIMARY SCLEROSING CHOLANGITIS: A META-ANALYSIS OF POPULATION-BASED STUDIES

Background

Primary sclerosing cholangitis (PSC) is a chronic liver disease associated with significant morbidity, mortality and healthcare utilization. Understanding the incidence of PSC is important in defining the burden of disease and planning for allocation of healthcare resources.

Aims

To conduct a systematic review and meta-analysis of population-based studies of the incidence of PSC and to assess temporal trends of incidence overtime.

Methods

Medline and Embase (from inception to May 10, 2021) were systematically searched to identify studies via the following inclusion criteria: 1) original articles, 2) population-based study of defined geographic area, 3) reported the incidence of PSC or provided data to calculate the incidence of PSC. Studies that assessed specific populations (e.g., pediatric-only, IBD-only) or reported less than 1 year of data were excluded. Abstracts and full texts were reviewed for inclusion and data was extracted independently in duplicate by two individuals (JC, AM). Meta-analyses were performed to calculate overall and country-specific incidence rates (per 100,000 persons) with 95% confidence intervals (CI). Meta-regression calculated the Average Annual Percentage Change (AAPC) of PSC incidence rates overtime.

Results

The initial search returned 3,958 abstracts. After duplicates were removed, abstracts (3,443) were screened, and full texts were reviewed (317), 17 studies met the criteria for inclusion and underwent data extraction. Meta-analysis included 6 studies with annual data contributing to the calculation of AAPC. Studies originated from 10 countries from North America, Europe, and Oceania; however, no population-based studies were published in Asia, Africa, or Latin America (Figure 1). Overall, the incidence rates of PSC was 0.82 per 100,000 (95% CI: 0.62, 1.02) (Figure 1). Incidence rates of PSC were significantly increasing overtime (AAPC: 4.56%; 95% CI: 0.45, 8.68).

Conclusions

The incidence of PSC is low at 0.82 per 100,000 but has been significantly increasing over time. Future studies on the incidence of PSC should be directed at Asia, Africa of Latin America to assess the global epidemiology of PSC.

Figure 1: Pooled incidence rate estimates of PSC per 100,000 person-years at risk.

Funding Agencies

None

A42 HETEROGENEITY IN EFFICACY AND SAFETY ENDPOINTS FOR PEDIATRIC CLINICAL TRIALS IN INFLAMMATORY BOWEL DISEASE: A NEED FOR HARMONIZATION

NOT PUBLISHED AT AUTHOR’S REQUEST

Funding Agencies: None

A146 THE EFFECTIVENESS OF USTEKINUMAB DOSE ESCALATION IN PATIENTS WITH ULCERATIVE COLITIS

Background

Ustekinumab (UST), an IgG1 antibody that targets IL-12/23, is an effective and safe treatment option for patients with inflammatory bowel disease (IBD). Cohort studies have shown that dose escalation is an effective strategy for reinducing and maintaining remission in Crohn’s disease patients who do not respond or lose response to standard dosing of UST. There are currently no published studies evaluating effectiveness of UST dose escalation in ulcerative colitis (UC) patients.

Aims

To assess the effectiveness of UST dose escalation in patients with moderate-to-severe UC who have not responded to or lost responsiveness to standard maintenance dosing (90mg SC every 8 weeks).

Methods

A retrospective cohort study was conducted at three centers. Consecutive patients with moderate-to-severe UC initiated on ustekinumab were enrolled.

Results

Data on 43 patients (26 males) are reported (to date, patients from 1 of 3 centres have been reviewed). Mean age was 40.2 years (±15.6). Mean duration of disease was 8.5 years (±5.8). Mean duration of follow up while on UST was 8.8 months (±7.2). In total, 28% (12) of patients underwent dose escalation: 8% (1) by way of IV reinduction, 58% (7) through interval shortening (every 4 weeks), and 33% (4) by both interval shortening and IV reinduction. Mean time to first dose escalation was 6.2 months (±4.1). Mean time to second dose escalation was 5.1 months (±1.2). Seven percent (3) of patients discontinued UST, with the mean timeframe being 5.3 months (±2.9). Three patients discontinued UST due to primary non-response with one proceeding onto surgery.

Time to normalization of CRP and FCP after initiation of UST is shown in Table 1.

Conclusions

Preliminary data demonstrates that 28% of patients in this cohort required UST dose escalation, with 33% requiring a second dose escalation. Only 7% of patients discontinued UST at 9 months of follow up. Longer term follow up of this cohort would determine if dose escalation is an effective strategy to extend durability of ustekinumab.

Table 1. Normalization of CRP and FCP

Funding Agencies

None

A24 GENERALIZABILITY OF CROHN’S DISEASE RANDOMIZED CONTROLLED TRIALS COMPARED TO CLINICAL PRACTICE

Background

There are no curative medical therapies for Crohn’s disease (CD). However, multiple novel treatment options are currently being evaluated in randomized controlled trials (RCTs). Historically, CD populations enrolled in RCTs have not reflected the heterogeneity of patients observed in clinical practice due to strict inclusion/exclusion criteria and protocolized trial procedures do not reflect day-to-day care. These factors have raised concerns that results from pivotal RCTs required for drug approval are poorly generalizable.

Aims

To assess the generalizability of CD RCTs, we evaluated the proportion of CD patients initiating ustekinumab or vedolizumab in clinical care who would have been eligible for enrolment in the corresponding phase 3 registrational induction trial, and the factors impacting trial eligibility.

Methods

This is a retrospective cohort study using data from two ambulatory IBD clinics in Calgary, AB. Our study population included consecutive adult (>=18 years) patients with a confirmed diagnosis of CD, newly initiated on ustekinumab or vedolizumab between January 1, 2018 and January 1, 2020. We then applied the inclusion/exclusion criteria from the phase 3 GEMINI II/III and UNITI I/II induction trials to determine the proportion of patients who would have been trial-eligible. We then tabulated the indications for trial exclusion to determine the characteristics of patients who would not have been reflected in the trial population.

Results

A total of 50 patients were included. The median age was 42.5 years. Most patients non-stricturing non-penetrating disease (44%, 22/50) and ileocolonic disease distribution (48%, 24/50). A total of 66% (33/50) would have been eligible for inclusion in GEMINI II/III and (30/50) 60% would be eligible for inclusion in UNITI I/II. The most common reasons for trial exclusion included extensive surgery (total colectomy/subtotal colectomy) with short bowel or ileostomy (n=12), surgery within 6 months of enrolment (n=3), multiple previous resections (n=2). Four patients were excluded based on intra-abdominal abscess. A total of 13 patients (26%) were temporarily ineligible due to recent biologic switch and would have required an 8-week washout prior to trial enrolment. Only two patients were excluded based on age (>80 years).

Conclusions

Although most patients on ustekinumab or vedolizumab would have been eligible for the respective pivotal trials, patients who have complications of disease, extensive surgery, or altered anatomy are not reflected in current RCTs.

Funding Agencies

None

Series representations and simulations of isotropic random fields in the Euclidean space

This paper introduces the series expansion for homogeneous, isotropic and mean square continuous random fields in the Euclidean space, which involves the Bessel function and the ultraspherical polynomial, but differs from the spectral representation in terms of the ordinary spherical harmonics that has more terms at each level.The series representation provides a simple and efficient approach for simulation of isotropic (non-Gaussian) random fields.

[The association between serum total homocysteine and subacute combined degeneration of spinal cord]

Objective: The research was aimed to investigate the association between serum total homocysteine (tHcy) and subacute combined degeneration of the spinal cord (SCD). Methods: A retrospective survey of 106 newly diagnosed patients with SCD were enrolled in this research who were treated in the department of neurology of Xijing Hospital from January 2008 to February 2019, meanwhile, 121 patients with spinal cord lesion (not SCD) and 104 neurology mild outpatients were selected as controls. Serum tHcy level was determined by using the chemiluminescent immunoassay assay. A multivariate logistic regression model was used to analyze the risk factors for SCD. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve, sensitivity, specificity and Youden index were used to evaluate the diagnostic efficacy of tHcy. Spearman correlation analysis was used to observe the correlation between tHcy and SCD severity. The SCD patients were categorized into normal or mild tHcy group, moderate tHcy group, and severe tHcy group based on tHcy levels. Clinical symptoms, nerve conduction velocity, magnetic resonance imaging (MRI) findings from the patients were studied. Results: The serum tHcy levels in SCD patients were 64.3(26.5, 98.8) μmol/L, while in patients with spinal cord lesion (not SCD) group were 13.7(10.8, 19.2) μmol/L, neurology mild outpatients were 10.6(8.2, 13.0) μmol/L, which was higher in SCD group (H=112.020,P<0.001), (H=165.525,P<0.001).The multivariate logistic regression model showed tHcy is the impact factor of SCD (OR=1.107, 95%CI:1.077-1.139, P<0.001). At ROC analysis, tHcy showed diagnostic value with an optimal cut-off value of 24.9 μmol/L (AUC 0.913, 95%CI: 0.875-0.951, sensitivity 79.2%, specificity 91.6%). Spearman correlation analysis showed that tHcy was positively correlated with functional disability rating scale (r=0.254, P=0.009). Conclusions: Serum tHcy is the risk factor for SCD and related to its disability. Focus on the increased level of tHcy plays a positive role in the diagnosis of SCD.

[Considerations on vaccines and immunization against COVID-19 for epidemic control in China]

The Delta variant of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a new global wave of the Coronavirus Disease 2019 (COVID-19) pandemic. COVID-19 vaccines currently available in China show high effectiveness against severe illness and death. However, transmission of the virus is not fully stopped by vaccination alone, therefore, integrated vaccination and non-pharmacological interventions is necessary to prevent and control the epidemic in the near future. Further expanded vaccine coverage of primary doses as well as booster shots in China's domestic population are needed to reduce severe illness and death. In order to provide evidence necessary for adjusting and optimizing immunization strategies and pandemic control measures, it is essential to conduct research on vaccine effectiveness against emerging variants, persistence of vaccine-induced protection, surveillance of adverse event following immunization with large-scale vaccine use, and modelling studies on strategic combinations of vaccination and non-pharmacological interventions.

Post-procedure anticoagulation in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

Post-procedural anticoagulation (PPAC) after primary percutaneous coronary intervention (pPCI) in patient with ST-segment elevation myocardial infarction (STEMI) may prevent recurrent ischemic events but may increase the risk of bleeding. No consensus has been reached on PPAC use.

Methods

Using data from the CCC-ACS registry, conducted between 2014 and 2019, we stratified all STEMI patients who underwent pPCI according to the use of PPAC or not. Inverse probability of treatment weighting (IPTW) and Cox proportional hazards model with hospital as random effect were used to analyze differences in in-hospital clinical outcomes: the primary efficacy endpoint was mortality, and the primary safety endpoint was major bleeding.

Results

Of 34,826 evaluable patients 26,272 (75.4%) were treated with PPAC, and were on average younger, more stable at admission with lower bleeding risk score, more likely to have comorbidities and multivessel disease, and more often treated within 12 hours of symptom onset than those without PPAC. After IPTW adjustment for baseline differences, PPAC was associated with significantly reduced risk of in-hospital mortality (0.9% vs. 1.8%; hazard ratio (HR): 0.62 [95% confidence interval 0.43, 0.89]; p&lt;0.001) and a nonsignificant difference in risk of in-hospital major bleeding (2.5% vs. 2.2%; HR: 1.05 [0.83, 1.32]; p=0.14).

Conclusions

PPAC in STEMI patients after pPCI was associated with reduced mortality without increasing major bleeding complications. Dedicated randomized trials with contemporary STEMI management are needed to confirm these findings.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Improving Care for Cardiovascular Disease in China – Acute Coronary Syndrome (CCC-ACS) project is a collaborative study of the American Heart Association (AHA) and the Chinese Society of Cardiology (CSC). The AHA has been funded by Pfizer and AstraZeneca for quality improvement initiatives through an independent grant. In-hospital clinical outcomes

[Surveillance and response to measles outbreaks in China, 2016-2020]

Objective: To understand the epidemiological characteristics of measles outbreaks in China from 2016 to 2020 and related outbreak investigations and response performances. Methods: The information about the incidence of measles outbreaks, the investigation and response of measles outbreaks in 31 provinces from 2016 to 2020 were collected from Measles Surveillance System, and the incidence of suspected measles outbreaks detected through sporadic case finding during the same period according to the measles outbreak definition was analyzed. Results: From 2016 to 2020, a total of 344 measles outbreaks were reported nationwide, involving 1 886 measles cases. The median of intervals between the first case onsets and reported outbreaks ranged from 4 to 10 days, the median of the numbers of involved cases ranged from 2 to 3, and the median of the duration of the epidemic ranged from 8 to 13 days, and some outbreaks had long durations of 65,44,28,63 and 13 days. The top three provinces with high number of reported outbreaks were Gansu, Beijing and Shandong. Among the reported outbreaks, 115 occurred in communities/villages, accounting for the highest proportion. The genotype identification results indicated that all the outbreaks in 2016 were caused by measles virus H1, and the proportion of the outbreaks caused by measles virus H1 decreased year by year since then, which was 88.57% (31/35) in 2017, 85.00% (17/20) in 2018 and 15.79% (3/19) in 2019 respectively. There was no outbreak caused by measles H1 reported in 2020, the 4 isolates all belonged to genotype D8. Active case findings were conducted in local medical institutions for 313 outbreaks, and measles-containing vaccine coverage surveys were conducted for 266 outbreaks. From 2016 to 2020, a total of 919 suspected measles outbreaks were detected nationwide, involving 4 212 measles cases. The top three provinces with suspected measles outbreaks were Xinjiang, Gansu and Sichuan. The suspected measles outbreaks also mainly occurred in communities/villages (493). Conclusions: The number, scale and duration of measles outbreaks were gradually decreasing, the measles outbreaks at the community level can not be ignored, and the local H1 genotypes tend to be gradually replaced by other genotypes. Improving the sensitivity of outbreak surveillance, promoting vaccination, expanding the vaccine coverage, timely and effective response to the outbreaks are the focus of measles elimination in China in the future.

Genome-wide identification of the light-harvesting chlorophyll a/b binding (Lhc) family in Gossypium hirsutum reveals the influence of GhLhcb2.3 on chlorophyll a synthesis

Light-harvesting chlorophyll a/b binding (Lhc) family proteins play a significant role in photosynthetic processes. Our objective was systematic identification and analysis of the Lhc family in cotton, as well as the relationship between Lhc family genes and chlorophyll synthesis during photosynthetic processes. We used genome-wide identification, phylogenetic analysis, chromosomal distribution and collinearity to examine potential functions of Lhc superfamily genes in upland cotton. Subcellular localization, qRT-PCR, a yeast two hybrid (Y2H) , and Virus-induced gene silencing (VIGS) experiment were used to explore function of GhLhcb2.3. Focusing on GhLhc family, gene structural analysis of G. hirsutum Lhc family genes (GhLhc) indicated the conservation of selected Lhc family members. The expression pattern of GhLhc proteins shows that Lhc family proteins are important for photosynthetic processes in leaves. Results of subcellular localization and qRT-PCR in different cotton varieties showed that GhLhcb2.3 is closely related to chloroplast chlorophyll. Y2H found extensive heteromeric interactions between the GhLhcb2.3 and GhLhcb1.4. Subcellular localization revealed that GhLhcb1.4 is located in chloroplasts. VIGS showed that GhLhcb2.3 influenced chlorophyll a synthesis. We comprehensively identified Lhc family genes in cotton, characterized these genes and reveal the influence of GhLhcb2.3 on chlorophyll a synthesis.

Salvage mandibular reconstruction: multi-institutional analysis of 17 patients

Unsuccessful mandibular reconstruction occasionally occurs, leaving the patient with undesirable function and contours. In such cases, second- or third-time corrective operations are challenging. However, published studies on the complicated retreatment of such patients are scarce. A retrospective analysis covering the years 2015-2019 was conducted in three centers. All 17 patients included had undergone prior failed mandibular reconstructions in other institutions. Salvage secondary or tertiary reconstructive surgeries were attempted and the results are presented. Major factors for these failed reconstructions included exposed non-vascularized bone grafts (n = 7, 41.2%), flap loss (n = 4, 23.5%), exposed artificial joint (n = 3, 17.6%), skewed occlusion with deformity (n = 1, 5.9%), non-union (n = 1, 5.9%), and recurrence (n = 1, 5.9%). Fibula flaps were transferred in 15 patients, while iliac flaps were used in two patients for mandibular re-do reconstructions. Virtual surgical designs were conducted in nine (52.9%) patients, with navigation-guided approaches performed in three cases. Postoperative functions were relatively favorable in these complicated mandibular re-do reconstruction cases. Mandibular symmetry (mandibular length and height; P = 0.002) and condylar position (P < 0.001) were regained after these re-do attempts. Secondary or tertiary mandibular re-do reconstruction can still achieve good functional outcomes with appropriate preoperative selection and well-conceived designs, especially with the aid of virtual surgery and navigation.

Dental Pulp Stem Cell Polarization: Effects of Biophysical Factors

Dental pulp stem cells (DPSCs) have the potential to polarize, differentiate, and form tubular dentin under certain conditions. However, the factors that initiate and regulate DPSC polarization and its underlying mechanism remain unclear. Identification of the factors that control DPSC polarization is a prerequisite for tubular dentin regeneration. We recently developed a unique bioinspired 3-dimensional platform that is capable of deciphering the factors that initiate and modulate cell polarization. The bioinspired platform has a simple background and confines a single cell on each microisland of the platform; therefore, it is an effective tool to study DPSC polarization at the single-cell level. In this work, we explored the effects of biophysical factors (surface topography, microisland area, geometry, tubular size, and gravity) on single DPSC polarization. Our results demonstrated that nanofibrous architecture, microisland area, tubular size, and gravity participated in regulating DPSC polarization by influencing the formation of the DPSC process and relocation of the Golgi apparatus. Among these factors, nanofibrous architecture, tubular size, and appropriate microisland area were indispensable for initiating DPSC polarization, whereas gravity served as an auxiliary factor to the process of DPSC polarization. Meanwhile, microisland geometry had a limited effect on DPSC polarization. Collectively, this work provides information on DPSC polarization and paves the way for the development of new biomaterials for tubular dentin regeneration.

[Directed differentiation of porcine induced pluripotent stem cells into forebrain GABAergic neuron progenitors]

OBJECTIVE

To establish an efficient protocol for directed differentiation of miniature-swine induced pluripotent stem cells (iPSCs) into GABAergic progenitors in a chemically defined system.

OBJECTIVE

We adopted a two-stage protocol for inducing the differentiation of porcine iPSCs. In the first stage, embryoid bodies (EBs) derived from porcine iPSCs after 3 days of suspension culture were induced in neural induction medium (containing SB431542, DMH1 and FGF2) till day 12 to differentiate into primitive neuroepithelia cells (NECs). In the second stage, the primitive NECs were induced in neural induction medium (containing Pur and B27) to obtain neural rosettes, which further differentiated into GABAergic neuron progenitors on day 21. After labeling with CM-DiI, the progenitor cells were stereotactically transplanted into the substantia nigra (SN) of 6-OHDA-lesioned PD model rats, and the cell survival, migration and differentiation in vivo were observed.

OBJECTIVE

Porcine iPSCs could be passaged stably on the feeder cell layer and expressed the pluripotent stem cell markers OCT4, Nanog, SSEA1and TRA-160. Karyotype analysis demonstrated the absence of contamination by cells from other species. On day 12 of induced differentiation, the cells formed adherent colonies containing NECs in the form of neural rosettes, which expressed the neuroepithelial markers PAX6, SOX2 and Nestin and the neurite marker beta Ⅲ Tubulin (Tuj1). After induction for 21 days, the NECs differentiated into GABAergic neural progenitors highly expressing NKX2.1 and FOXG1. Eight weeks after transplantation, the iPSCs-iGABA progeniters survived in the striatum of the PD rats, where they differentiate into GABAergic neurons and TH+ neurons and significantly improved dyskinesia of the rats.

OBJECTIVE

The miniature-swine iPSCsderived GABA progenitors may serve as promising donor cells for neural grafting for treatment of neurodegenerative diseases.

Bilateral vision loss as the initial presentation for central nervous system involvement of mantle cell lymphoma: A case series

Purpose

Mantle cell lymphoma is a rare aggressive subtype of non-Hodgkins B cell lymphoma. It typically presents with asymptomatic monoclonal lymphocytosis, lymphadenopathy or bulky extranodal disease. Mantle cell lymphoma rarely affects the central nervous system. We present two cases in which vision loss was the initial symptom of central nervous system involvement by the malignancy.

Observations

Both patients initially received high dose intravenous steroids with notable improvement in their vision.

Conclusions and importance

Early detection and management of optic nerve infiltration by mantle cell lymphoma is essential as it improves visual outcomes and enables prompt management of the patient's systemic disease.

LINC00106 prevents against metastasis of thyroid cancer by inhibiting epithelial-mesenchymal transition

OBJECTIVE

Thyroid cancer (TC) is a common malignant tumor of the endocrine system, and its morbidity and mortality are in the high places. Recent studies have focused on exploring biological markers and targeted therapy for TC. This research aims to elucidate the role of LINC00106 in the progression of TC and the regulatory mechanisms.

PATIENTS AND METHODS

Differential level of LINC00106 in a downloaded profile containing TC and normal tissues from GEPIA database was analyzed. Subsequently, its level in TC tissues and cell lines was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between LINC00106 level and clinical data of TC patients was assessed, including age, tumor staging, lymphatic metastasis, and overall survival. After transfection of si-LINC00106, TC cell metastasis was evaluated by wound healing and transwell assay. Relative levels of E-cadherin, N-cadherin, β-catenin, and Vimentin regulated by LINC00106 were determined using qRT-PCR and Western blot.

RESULTS

LINC00106 was downregulated in TC tissues than normal ones. Its level was correlated to tumor staging, lymphatic metastasis and overall survival in TC patients. The knockdown of LINC00106 in BCPCP and TPC-1 cells enhanced migratory and invasive abilities and triggered the process of epithelial-mesenchymal transition (EMT).

CONCLUSIONS

LINC00106 is lowly expressed in TC specimens, which attenuates migratory and invasive abilities in TC by inhibiting EMT as a tumor suppressor.

CircRNA_009934 induces osteoclast bone resorption via silencing miR-5107

OBJECTIVE

We aimed to explore the expression of circRNA_009934 in osteoclast, as well as its potential roles in regulating osteoclastogenesis and bone resorption via regulating miR-5107.

MATERIALS AND METHODS

We performed qRT-PCR analysis to examine the expression of circRNA_009934 in osteoclast in distinctive stages. We used CCK-8 assay to detect the cell proliferation ability. Correlation analysis between the expression levels of circRNA_009934 and miR-5107 was performed using statistical analysis. Bioinformatics prediction was performed to predict the binding site of circRNA_009934 and miR-5107, subsequently followed by Luciferase assay for validation. The mice TRAF6 3'-UTR were cloned into the Luciferase reporter vector and miR-5107 binding mutants were constructed to validate the inhibited regulation of miR-5107 to the expression of TRAF6.

RESULTS

Our results showed that expression of circRNA_009934 was increased during osteoclast differentiation. CircRNA_009934 expression was closely correlated with osteoclastogenesis and bone resorption activity. Bioinformatics prediction and Luciferase assay demonstrated that circRNA_009934 served as a ceRNA of miR-5107 and regulated its downstream TRAF6 expression.

CONCLUSIONS

We first demonstrated that circRNA_009934 expression was increased in osteoclasts, which promoted osteoclastogenesis by serving as a ceRNA of miR-5107 and regulated the expression of TRAF6.

A173 INNOVATIVE CARE FOR INFLAMMATORY BOWEL DISEASE PATIENTS DURING THE COVID-19 PANDEMIC: USE OF BEDSIDE INTESTINAL ULTRASOUND TO OPTIMIZE MANAGEMENT

Background

The COVID-19 pandemic has led to significant alterations in the ability to deliver outpatient care to patients with inflammatory bowel disease (IBD) including endoscopic evaluation. This has highlighted the need for alternative, accurate, non-invasive strategies to safely assess disease activity.

Aims

The aim of this study is to describe the impact of point of care intestinal ultrasound (IUS) in a university-based tertiary care IBD urgent access clinic.

Methods

We prospectively evaluated a comprehensive care pathway which incorporated outpatient sigmoidoscopy and intestinal ultrasound with the purpose of directing further ambulatory clinical care and avoiding hospitalization or hospital-based investigations including endoscopy during the COVID pandemic for patients with established IBD with symptoms suggestive of a disease flare, or those at high risk of a new diagnosis of IBD. Non-invasive markers C Reactive Protein (CRP) and fecal calprotectin (fCal) were collected where available. Patients were pre-screened for influenza-like illness, as COVID-19 testing was not available for this population during the study period. Substantial management changes were defined as addition of any medications, biologic switch/ optimization, and or referral for surgical consultation.

Results

Between March 15^th and June 30^th 2020, a total of 72 patients were seen in the urgent access clinic. All patients were seen within 7 days of referral. The majority were female 57% (41/72) and/ or had Crohn’s disease 65.5% (47/72) (Table 1). Of these, 84.7% (61/72) underwent a substantial management change based on features of active inflammation detected by either IUS alone (53% 38/72) sigmoidoscopy alone (12.5% 9/72) or combination IUS with in-clinic sigmoidoscopy (32% 23/72) in addition to CRP and fCal. Three new diagnoses of IBD were made: one colonic Crohn’s and 2 with ulcerative colitis. One pregnant patient avoided all acute care utilization. Five patients were referred to colorectal surgery for urgent resection including two patients admitted directly for emergent operations. No patients required visits to the emergency department. Furthermore, there have been no unscheduled hospitalizations occurred in this cohort since inception March 23, 2020 til November 15^th 2020.

Conclusions

The implementation of IUS in a centralized, urgent access clinic pathway resulted in efficient and meaningful changes in IBD management while sparing the need for acute care services including ER visits, need for in-hospital endoscopy, and hospitalization. The pandemic highlights the utility of this patient-center tool and supports expansion of wider IUS adoption.

Funding Agencies

None

A80 IMPACT OF THE COVID-19 PANDEMIC IN IBD PATIENT CARE

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

A21 ULCERATIVE COLITIS-ASSOCIATED E. COLI PATHOBIONTS POTENTIATE COLITIS IN SUSCEPTIBEL HOSTS

Background

Ulcerative colitis (UC) is a chronic inflammatory condition linked to intestinal microbial dysbiosis, including the expansion of E. coli strains related to extra-intestinal pathogenic E. coli. These “pathobionts” exhibit pathogenic properties, but their potential to promote UC is unclear due to the lack of relevant animal models.

Aims

We explored the potential to establish a mouse model of GI infection by the UC-associated E. coli strain p19A, as well as characterize the pathogenic features of p19A.

Methods

We used a representative UC pathobiont strain (p19A), and mice lacking single immunoglobulin and toll-interleukin 1 receptor domain (SIGIRR), a deficiency increasing susceptibility to gut infections. Vancomycin-pretreated Sigirr-/- mice were subsequently gavaged with the control E. coli DH10B (a derivative of commensal strain K-12) or p19A. One day after infection, mice were exposed to 2.5% dextran sodium sulfate (DSS) in their drinking water for another 4 days.

Results

Strain p19A was found to adhere to the cecal mucosa of Sigirr-/- mice, causing modest inflammation. Moreover, it dramatically worsened DSS-induced colitis. This potentiation was attenuated using a p19A strain lacking α-hemolysin genes, or when we targeted pathobiont adherence using a p19A strain lacking the adhesin FimH, or following treatment with FimH antagonists.

Conclusions

Thus, UC pathobionts adhere to the intestinal mucosa, and worsen the course of colitis in susceptible hosts in a manner dependent on specific virulence factors, including α-hemolysin and FimH.

Funding Agencies

CCC, CIHR

A123 DEFINING CROHN’S DISEASE STRICTURES USING INTESTINAL ULTRASOUND COMPARED TO HISTOPATHOLOGY

Background

Fibrostenotic Crohn’s Disease (CD) is a challenging phenotype often leading to surgical resection. Diagnostic imaging is an invaluable tool to diagnose CD strictures. MRE (Magnetic Resonance Enterography) is the most widely used modality for evaluating strictures, but is limited by access and cost. The current definition of strictures is based only on MRE or CT (computed tomography). Strictures are defined as increased bowel wall thickness (BWT), narrowed luminal apposition, and pre-stenotic dilation &gt; 3cm according to CONSTRICT MR/CT expert consensus criteria. However, this definition has not been studied in intestinal US (IUS). IUS is a cost-effective, easily repeatable, and well-tolerated tool shown to have equal accuracy to MRE in diagnosing and monitoring CD.

Aims

The objective of this study was to assess the utility of identifying strictures with IUS using CONSTRICT definition.

Methods

In this retrospective pilot study, 30 of 80 CD patients who underwent small bowel resection (gold standard for stricture diagnosis) between 2015–2019 with IUS within 6 months prior to surgery were randomly identified for chart review. IUS was performed in a fasted state without oral contrast. Data extracted included confirmed stricture on resection specimens defined as having fibrosis and prestenotic dilation. Fistulizing disease was excluded. Student’s t-tests, sensitivities, specificities, positive (PNV) and negative predictive values (NPV) were calculated for IUS in detecting strictures.

Results

Of the 30 CD patients evaluated, 20 patients had fibrostenosis on pathology and IUS reports. Only 40% (8/20) met CONSTRICT criteria for stricture diagnosis on IUS, despite having a stricture on pathology. All patients had elevated BWT and luminal narrowing, but 60% (12/20) did not have prestenotic dilation &gt; 3cm. Mean dilation was 2.9 cm (SD 1.38) and was significantly different from the mean stricture diameter of 1.3cm (SD 0.59 cm, p=0.0001, 95% CI: 0.9–2.2). Mean BWT was 8.7 mm (SD: 2.5, range 5–15) where normal is &lt; 3mm, and mean luminal apposition was 2.3 mm (SD 1.2, range 0.2–5.8mm). IUS has a sensitivity of 95.2% (95% CI: 76.2 - 99.9%), specificity of 66.7% (95% CI: 29.9 - 92.5%), PPV of 87.0% (95% CI: 72.5–94.4), and NPV of 85.7% (95% CI 45.6–97.7%) in detecting strictures when compared to gold standard.

Conclusions

CONSTRICT criteria for diagnosing fibrostenotic CD on CT/MR may not be applicable to IUS. In this study, only 40% of patients met criteria despite having histologic confirmed strictures. Thus, perhaps additional criteria of stricture diameter &lt; 50% of prestenotic dilation size is most appropriate for IUS. This pilot study provides the initial data to delineate an IUS stricture definition for future validation and to inform both clinical practice and trial design.

Funding Agencies

None

A155 REAL-WORLD USE OF CORTIMENT IN ULCERATIVE COLITIS: A POPULATION-BASED STUDY

Background

Ulcerative colitis (UC) is a relapsing and remitting disease with variable severity. BudesonideMMX (Cortiment®) was approved by Health Canada for the treatment of mild to moderate UC in July 2016. It offers the advantage of extensive first pass hepatic metabolism resulting in decreased systemic corticosteroid toxicity. Most public drug plans in Canada do not cover it, limiting its use to private insurance and self-pay.

Aims

To characterize the UC patients who use Cortiment® and explore prescribing patterns and short-term outcomes.

Methods

Population-based administrative data identified patients who were covered by the Alberta Health Care Insurance Plan and dispensed Cortiment® from August 1, 2016 to December 31, 2017. Analyses identified: age, sex, rural/urban status, Material [MDI] and Social Deprivation Indices [SDI], UC-related medications 6-months before and 10-weeks following Cortiment® dispensing, and disease exacerbation indicators (new dispense of corticosteroids, hospitalization with inflammatory bowel disease (IBD) as most responsible diagnosis, or IBD-related surgery).

Results

We identified 427 UC patients dispensed Cortiment®. The median age was 47 years (25th %: 35; 75th %: 59) and 57.4% were females. Most individuals (91.3%, n=390) resided in an urban setting, as compared to approximately 73% of all UC cases. Distribution of patients across SDI was consistent while the MDI had a higher proportion in the more well-off categories. 77.5% had a UC-related drug therapy in the 6 months prior to Cortiment® dispensing and 71.7% had a UC-related drug dispensed in the 10-weeks following. Approximately, 30% had a disease exacerbation indicators in the 10 weeks following dispensing: 24.8% new corticosteroid, 3.7% UC-related hospitalization, and &lt;2.3% UC-related surgery.

Conclusions

Despite lack of public drug coverage, Cortiment® was dispensed across socioeconomic classes. The high dispensing within urban sites suggests that rural UC patients may have less access to Cortiment®. While a quarter of Cortiment® dispensings had a new concurrent dispensing of prednisone, &lt;5% of these patients were admitted to hospital for a flare of UC.

Funding Agencies

Ferring Pharmaceuticals

The feasibility of dual-energy CT to predict the probability of symptomatic intracerebral haemorrhage after successful mechanical thrombectomy

AIM

To study the ability of dual-energy computed tomography (DECT) after successful mechanical thrombectomy (MT) to predict symptomatic intracerebral haemorrhage (sICH) in anterior circulation acute ischaemic stroke (AIS).

MATERIALS AND METHODS

From June 2018 to February 2020, 102 AIS patients with DECT performed immediately after successful MT were enrolled prospectively. According to the presence of iodine contrast media extravasation (ICME) on DECT and subsequent sICH development, patients were classified into four groups. The neurological outcome was compared among groups. Imaging parameters, together with clinical factors, were investigated for sICH prediction based on a linear logistic regression model after class-imbalance resolved by Synthetic Minority Sampling Technique (SMOTE) method.

RESULTS

Among 102 patients, patients (14.7%, 15/102) with the presence of sICH experienced worse outcomes than others without sICH (p<0.001). No case without ICME was observed with sICH development (0/102). The parameters derived from DECT have excellent performance for sICH prediction after successful MT, which is better than clinical predictive model boosted data (area under the curve [AUC]: DECT 0.87 versus clinical prediction 0.65), cross-validation results (AUC: DECT 0.87 versus clinical prediction 0.65), and original data (AUC: DECT 0.85 versus clinical prediction 0.68). By combining clinical and radiological parameters, the predictive performance for sICH could be further improved with an AUC of 0.90 (95% CI: 0.85-0.96).

CONCLUSIONS

Based on DECT parameters acquired immediately after successful MT, the present model was more efficient than the clinical model for accurate prediction of sICH. Rho and ICME volume appeared to be the best parameters for predicting sICH using DECT.

[Investigation and analysis of reproductive health status of female street cleaners in a district]

Objective: To explore the reproductive health status of the female street cleaners in Chaoyang district of Beijing and its influencing factors. Methods: In July 2018, a total of 647 questionnaires were sent out to female road cleaning and sanitation workers in the whole district, 613 of which were valid, with an effective rate of 94.7%. Frequency or percentage (%) is used for statistical description of counting data, and mean standard deviation is used for measurement data. The influencing factors were analyzed by 2 test. Results: The average age of 613 female road sweepers in Chaoyang District of Beijing was 42.01 (SD=6.69) years old, including 535 married female workers (87.28%) , 356 middle school and below educated (58.08%) , 292 non Beijing registered (47.63%) , accounting for (/613) , (/613) female workers working hours >8 hours per day 110 (17.94%) , weekly rest <2 days 341 (55.63%) . 144 (23.49%) women workers did not have regular gynecological examination, 119 (19.41%) had reproductive tract infections, 177 (28.87%) had abnormal menstruation in recent 6 months. Drinking, sexual behavior outside marriage, night shift and job satisfaction were all the influencing factors (P<0.05) . The increasing age, working years, drinking, household registration in other places and the decreasing satisfaction of women workers＇ rights and interests protection were all the influencing factors (P<0.05) . Conclusion: The reproductive health status of female road sweepers in Chaoyang District of Beijing is not optimistic.

Rapid detection of extended-spectrum β-Lactamases producers in Enterobacteriaceae using a calorimetry approach

AIM

To design and assess a novel protocol that employs isothermal titration calorimetry (ITC) for rapid detection of extended-spectrum β-lactamase (ESBL)-producers in clinical pathogens.

METHODS AND RESULTS

A total of 69 clinical Enterobacteriaceae isolates were examined in the new ESBL-ITC test by examining the heat profiles associated with enzyme hydrolysis of different substrates (imipenem, cefotaxime and clavulanic acid). The presence of β-lactamase genes in the bacteria tested was confirmed by PCR and DNA sequencing. Comparative analysis between ESBL-ITC and conventional minimum inhibitory concentrations (MIC)/combined disk method (CDM) showed high agreement between the two assays. However, the ESBL-ITC test had a remarkable advantage of providing testing result within 1 h, in comparison to the 32-48 h required by MIC/CDM.

CONCLUSIONS

The ESBL-ITC test developed in this work offers a new option for rapid and accurate detection of ESBL-producers.

SIGNIFICANCE AND IMPACT OF THE STUDY

Timely detection of ESBL-producers is vital to guide the decision-making process in clinical treatment as well as in hospital-infection control. The new ESBL-ITC test provides a rapid phenotypic assay that can be further adapted for clinical diagnosis of ESBL-producing pathogens.

DICER1-AS1 Promotes the Malignant Behaviors of Colorectal Cancer Cells by Regulating miR-296-5p/STAT3 Axis

Background

Long non-coding RNA (lncRNA) exerts a regulatory role in the occurrence and progression of tumors. This study aimed at probing into the function and mechanism of lncRNA DICER1 antisense RNA 1 (DICER1-AS1) in colorectal cancer (CRC).

Methods

The expressions of DICER1-AS1, miR-296-5p and STAT3 mRNA were tested by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay was employed to detect cell proliferation, and Transwell was used to detect cell migration and invasion. In addition, the expressions of apoptosis-related proteins Bax and Bcl2 were detected by Western blot. Interactions between DICER1-AS1 and miR-296-5p, and miR-296-5p and STAT3 were predicted and determined by bioinformatics analysis, luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay.

Results

The expressions of DICER1-AS1 and STAT3 mRNA were significantly up-regulated while miR-296-5p expression was remarkably down-regulated in CRC tissues and cell lines. Over-expression of DICER1-AS1 or transfection of miR-296-5p inhibitors could promote the proliferation, migration and invasion and inhibit apoptosis of CRC cells, whereas knockdown of DICER1-AS1 or transfection of miR-296-5p mimics had the opposite effects. Additionally, DICER1-AS1 could down-regulate miR-296-5p expression via sponging it. DICER1-AS1 also enhanced the expression of STAT3, which was identified as a target gene of miR-296-5p.

Conclusion

DICER1-AS1 acts as an oncogenic lncRNA in CRC via modulating miR-296-5p/STAT3 axis. Our results provide a new direction for the diagnosis and treatment of CRC.

Combined genome-wide association study and transcriptome analysis reveal candidate genes for resistance to Fusarium ear rot in maize

Fusarium ear rot, caused by Fusarium verticillioides, is a devastating fungal disease in maize that reduces yield and quality; moreover, F. verticillioides produces fumonisin mycotoxins, which pose serious threats to human and animal health. Here, we performed a genome-wide association study (GWAS) under three environmental conditions and identified 34 single-nucleotide polymorphisms (SNPs) that were significantly associated with Fusarium ear rot resistance. With reference to the maize B73 genome, 69 genes that overlapped with or were adjacent to the significant SNPs were identified as potential resistance genes to Fusarium ear rot. Comparing transcriptomes of the most resistant and most susceptible lines during the very early response to Fusarium ear rot, we detected many differentially expressed genes enriched for pathways related to plant immune responses, such as plant hormone signal transduction, phenylpropanoid biosynthesis, and cytochrome P450 metabolism. More than one-fourth of the potential resistance genes detected in the GWAS were differentially expressed in the transcriptome analysis, which allowed us to predict numbers of candidate genes for maize resistance to ear rot, including genes related to plant hormones, a MAP kinase, a PR5-like receptor kinase, and heat shock proteins. We propose that maize plants initiate early immune responses to Fusarium ear rot mainly by regulating the growth-defense balance and promoting biosynthesis of defense compounds.

Electron Microprobe/SIMS Determinations of Al in Olivine: Applications to Solar Wind, Pallasites and Trace Element Measurements

Electron probe microanalyzer measurements of trace elements with high accuracy are challenging. Accurate Al measurements in olivine are required to calibrate SIMS implant reference materials for measurement of Al in the solar wind. We adopt a combined EPMA/SIMS approach that is useful for producing SIMS reference materials as well as for EPMA at the ~100 μg g^-1 level. Even for mounts not polished with alumina photoelectron spectroscopy shows high levels of Al surface contamination. In order to minimize electron beam current density, a rastered 50 × 100 μm electron beam was adequate and minimized sensitivity to small Al-rich contaminants. Reproducible analyses of eleven SIMS-cleaned spots on San Carlos olivine agreed at 69.3 ± 1.0 μg g^-1• The known Al mass fraction was used to calibrate an Al implant into San Carlos. Accurate measurements of Al were made for olivines in the pallasites: lmilac, Eagle Station and Springwater. Our focus was on Al in olivine, but our technique could be refined to give accurate electron probe measurements for other contamination-sensitive trace elements. For solar wind, it is projected that the Al/Mg abundance ratio can be determined to 6%, a factor of 2 more precise than the solar spectroscopic ratio.

MFN2 contributes to metabolic disorders and inflammation in the aging of rat chondrocytes and osteoarthritis

OBJECTIVE

Metabolic disorders and inflammation of chondrocytes are major pathological changes in aging cells and osteoarthritis (OA). Recent studies demonstrated age-related mitochondrial dysfunction may be a key contributing factor in the development of OA. Mitofusin 2 (MFN2) is a key regulator of mitochondrial fusion, cell metabolism, autophagy and apoptosis. This study was performed to ascertain whether MFN2 was involved in the aging of chondrocytes and OA.

METHODS

Metabolic measurements were taken in rat chondrocytes between different ages (3-week, 5-month, 12-month). MFN2 activity was detected in both human and rat chondrocytes during aging and OA. Then, knockdown of MFN2 with small interfering RNA (siRNA) was performed to confirm whether MFN2 contributes to metabolic changes. Lentiviruses were used to establish MFN2-overexpression/knockdown OA models both in vivo and in vitro to confirm whether MFN2 contributes to OA progress. Further, regulatory mechanism of MFN2 was assessed and interaction between MFN2 and PARKIN was performed.

RESULTS

A metabolic shift to mitochondrial respiration was confirmed in rat chondrocytes during aging. MFN2 expression was elevated in both human and rat chondrocytes during aging and OA. Knockdown of MFN2 with siRNA reversed the age-related metabolic changes in rat chondrocytes. Overexpression of MFN2 exacerbated inflammation and OA progress, while knockdown of MFN2 ameliorated inflammation and OA progress. Further, MFN2 could be ubiquitinated by PARKIN, declined PARKIN expression during aging and OA might result in elevated MFN2 expression.

CONCLUSIONS

Elevated MFN2 contributes to metabolic changes and inflammation during aging of rat chondrocytes and osteoarthritis.

Dietary supplementation with Bacillus subtilis DSM 32315 alters the intestinal microbiota and metabolites in weaned piglets

AIM

The study was conducted to investigate the effects of dietary Bacillus subtilis (BS) DSM 32315 on the intestinal microbiota composition and metabolites of weaned pigs.

METHODS AND RESULTS

Sixty-four piglets were allocated to two groups (control and BS), each group including eight replicates with four piglets. Dietary BS DSM 32315 increased (P < 0·05) the abundances of jejunal Leucobacter and Cupriavidus, ileal Thermus, Coprococcus and Bifidobacterium, as well as colonic Succiniclasticum; and increased the concentrations of ileal straight-chain fatty acids, colonic propionate, branched-chain fatty acids (BCFAs), and tyramine, but decreased (P < .05) the colonic indole concentration. The ileal and colonic microbial community structure tended to cluster into two groups. LEfSe analysis identified five microbial biomarkers in jejunum and eight biomarkers in ileum in the BS group, and three biomarkers in colon in the control group. The ileal Bifidobacterium abundance was positively correlated (P < 0·05) with isovalerate concentration, while the colonic Actinobacteria and Lactobacillus abundances were negatively correlated (P < 0·05) with indole concentration.

CONCLUSION

These findings suggest that dietary supplementation with BS DSM 32315 could alter the diversity, composition, and metabolites of intestinal microbiota in weaned piglets.

SIGNIFICANCE AND IMPACT OF THE STUDY

Weaned piglets are often accompanied with impaired gastrointestinal tract and intestinal disorder affecting their growth. This study demonstrated that dietary BS DSM 32315 presented a beneficial role in gut health via regulating intestinal microbiota composition and metabolites.

ELECTROACUPUNCTURE IMPROVES INSULIN SENSITIVITY IN HIGH-FAT DIET-INDUCED INSULIN RESISTANT RATS BY ACTIVATING SIRT1 AND GLUT4 IN QUADRICEPS FEMORIS

OBJECTIVES

To assess the effects of electroacupuncture (EA) at the Zusanli (ST36), Guanyuan (CV4), Zhongwan (CV12), and Fenglong (ST40) acupoints on sirtuin 1 (SIRT1) and glucose transporter type 4 (GLUT4) expression in high-fat diet (HFD)-induced insulin-resistant (IR) rats.

METHODS

Wistar rats were divided into normal control (NC), HFD, and HFD+EA groups. NC rats were fed a standard chow diet and did not receive EA. After being fed an HFD for eight weeks, rats in the HFD+EA group received EA at 2 Hz five times a week for eight weeks. Rats in the HFD group did not receive EA.

RESULTS

In HFD-induced IR rats, EA inhibited body weight increase and water intake, which were observed in HFD rats. EA had no effect on fasting blood glucose and postprandial blood sugar levels. Intraperitoneal insulin tolerance testing revealed that EA enhanced insulin sensitivity in HFD-induced IR rats. Compared with NC rats, SIRT1 and GLUT4 were downregulated in the quadriceps femoris of HFD-fed rats but were increased after eight weeks of EA stimulation.

CONCLUSIONS

EA enhanced HFD-induced insulin resistance by activating SIRT1 and GLUT4 in the quadriceps femoris. These results provide powerful evidence supporting the beneficial effects of EA on HFD-induced insulin resistance.

SAT0447 CORRELATES OF RADIAL BONE MICROARCHITECTURES IN OLDER ADULTS

Background:

Weight, dietary patterns, vitamin D, physical activity and grip strength have been suggested to be associated with bone loss in older adults. However, studies have yet been performed to investigate the associations between these factors and radial bone microarchitecture.

Objectives:

This study aimed to describe the associations of weight, dietary patterns, serum 25-hydroxyvitamin D (25(OH)D) concentrations, physical activity and grip strength with bone measures in older adults.

Methods:

Cross-sectional data on 201 older adults (mean age 72 years, female 46%) from a population-based cohort study were analysed. Weight, dietary patterns, serum 25(OH)D concentrations, physical activity (steps per day), grip strength were collected and analysed from baseline to 10-year follow-up. Areal bone mineral density (aBMD) at spine, hip and whole body were measured by dual-energy X-ray absorptiometry (DXA). Radial cortical and trabecular bone microarchitectures were measured by high-resolution peripheral computed tomography (HRpQCT). Multivariable linear regression was used to analyse associations of study factors with bone measures.

Results:

Weight was positively associated with radial bone area (total: β=0.18, 95% CI: 0.07, 0.29; cortical: β=0.12, 95% CI: 0.03, 0.21; trabecular: β=0.18, 95% CI: 0.05, 0.32), and was inversely associated with compact cortical volumetric bone mineral density (vBMD) (β= -0.19, 95% CI: -0.37, -0.01) and trabecular thickness (β= -0.25, 95% CI: -0.43, -0.07). Ten-year changes in weight were not significantly associated with bone measures, apart from radial trabecular separation (β= 0.15, 95%CI: 0.009, 0.28). Western dietary pattern scores were inversely associated with radial vBMD (total: β= -0.17, 95% CI: -0.32, -0.01; cortical: β= -0.19, 95% CI: -0.34, -0.04; compact cortical: β= -0.19, 95% CI: -0.34, -0.04; outer transitional zone: β= -0.20, 95% CI: -0.35, -0.06), and were positively associated with cortical porosity (cortical: β= 0.18, 95% CI: 0.03, 0.33; compact cortical: β= 0.19, 95% CI: 0.04, 0.34; outer transitional zone: β= 0.20, 95% CI: 0.06, 0.35). Steps per day were not significantly associated with bone measures, apart from inner transitional zone area and thickness (β= 0.12, 95% CI: 0.003, 0.24; β= 0.19, 95% CI: 0.05, 0.33). Healthy food pattern scores, serum 25(OH)D and grip strength were not significantly associated with radial HRpQCT measures.

Conclusion:

Higher weight, but not weight change, was beneficial for radial cortical and trabecular bone area but also associated with worse compact cortical vBMD and trabecular thickness. Higher western dietary pattern scores had adverse effects on radial vBMD and cortical porosity while physical activity had inconsistent associations.

Disclosure of Interests:

None declared

0380 Association of Day-to-Day Variability in Rest-Activity Circadian Rhythm with Sleep Quality Among Law Enforcement Officers

Introduction

Poor sleep quality may be attributed to several occupational factors and has been linked to adverse health outcomes, including cardiovascular disease. Recent epidemiologic studies suggest rest-activity circadian rhythm (RAR) as a possible determinant of poor sleep quality. The focus of these studies has been on the magnitude of the parameters of RAR with little attention to the impact of their day-to-day fluctuation. We examined association of daily variation in parameters of RAR with sleep quality.

Methods

Participants (n=280) were officers from the Buffalo Cardio-metabolic Occupational Police Stress Study (2004-2009). Sleep quality was determined using the Pittsburgh Sleep Quality Index (PSQI). Participants wore wrist actigraph for a minimum of seven days. A cosine curve was fit to measure goodness of fit and estimate the mean values of the three parameters of RAR: Mesor, Amplitude, and Acrophase. Day-to-day variability of the parameters were assessed by fitting the cosine function separately for each day and computing the sample standard deviation across the days. Poisson regression models were conducted adjusting for demographic, lifestyle, and occupational factors.

Results

The prevalence of poor sleep quality was 50.3%. Poor sleep quality was 56% higher in officers with the largest day-to-day variability in Mesor (PR=1.56, 95%CI:1.11 - 2.19) compared to those with the lowest daily variation. Similar estimates were found for Amplitude (PR=1.42, 1.03 - 1.95), Acrophase (PR=1.86, 1.29 - 2.67), and measure of goodness of fit (PR=1.54, 1.13 - 2.11). On the other hand, mean values of RAR parameters were not significantly associated with poor sleep quality.

Conclusion

Results suggest larger daily variation in parameters of RAR is associated with a decrease in sleep quality. Given that day-to-day variation in RAR may increase the odds of poor sleep quality, future studies ought to address risk factors for higher daily fluctuations in RAR which could aid in developing intervention measures.

Support

CDC/NIOSH grant 1R01OH009640-01A1

0797 Restless Legs Syndrome and Perceived Olfactory and Taste Dysfunction: A Community-Based Study

Introduction

Restless legs syndrome (RLS), an under-recognized sensorimotor condition worldwide, is thought to be a prodromal symptom of Parkinson’s disease as suggested by previous evidences. However, its association with prodromal chemosensory impairments, including olfactory or taste dysfunction, has remained largely unknown. Few studies of small sample sizes were conducted in predominantly Caucasian populations and results were inconsistent.

Methods

We performed a cross-sectional analysis including 90,337 Chinese adults free of neurodegenerative diseases in the Kailuan study in 2016. Presence of RLS was defined using revised RLS diagnostic criteria and further verified by Cambridge-Hopkins questionnaire for RLS. Perceived olfactory and taste dysfunction was collected via a questionnaire. The association between RLS and perceived olfactory and taste dysfunction was assessed using logistic regression model, adjusting for potential cofounders such as age, sex, smoking, alcohol consumption sleep conditions and medical history.

Results

RLS was associated with high odds of having perceived olfactory and/or taste dysfunction (adjusted odds ratio =5.92; 95% confidence interval, 3.11, 11.3). The significant association persisted when using Cambridge-Hopkins questionnaire for RLS (adjusted odds ratio =5.55; 95% confidence interval, 2.37-13.0) or when excluding participants with major chronic diseases.

Conclusion

RLS was associated with increased odds of perceived olfactory and taste dysfunction.

Support

This research was supported by start-up grant from the College of Health and Human Development and the Department of Nutritional Sciences, Pennsylvania State University, the Institute for CyberScience Seed Grant Program, Pennsylvania State University, and Natural Science Foundation of Hebei Province (H2018209318).

[Guidelines for the use of post-traumatic tetanus vaccines and passive immune preparation]

Post-traumatic tetanus is the main type of non-neonatal tetanus. To reduce the incidence and mortality rateof tetanus and guide the primary medical institutions to prevent and control tetanus after trauma, the National Immunization Planning Technical Working Group of the Chinese Center for Disease Control and Prevention has compiled this document in the reference with Position Paper by World Health Organization, and the latest research progress both at home and abroad. The guidelines focus on the basic procedures for the prevention and treatment of post-traumatic tetanus, the application of tetanus vaccines and immune preparation, and pre-exposure immunization in high-risk populations of trauma.

MR Imaging Correlates for Molecular and Mutational Analyses in Children with Diffuse Intrinsic Pontine Glioma

BACKGROUND AND PURPOSE

Recent advances in molecular techniques have characterized distinct subtypes of diffuse intrinsic pontine gliomas. Our aim was the identification of MR imaging correlates of these subtypes.

MATERIALS AND METHODS

Initial MRIs from subjects with diffuse intrinsic pontine gliomas recruited for a prospective clinical trial before treatment were analyzed. Retrospective imaging analyses included FLAIR/T2 tumor volume, tumor volume enhancing, the presence of cyst and/or necrosis, median, mean, mode, skewness, kurtosis of ADC tumor volume based on FLAIR, and enhancement at baseline. Molecular subgroups based on EGFR and MGMT mutations were established. Histone mutations were also determined (H3F3A, HIST1H3B, HIST1H3C). Univariate Cox proportional hazards regression was used to test the association of imaging predictors with overall and progression-free survival. Wilcoxon rank sum, Kruskal-Wallis, and Fisher exact tests were used to compare imaging measures among groups.

RESULTS

Fifty patients had biopsy and MR imaging. The median age at trial registration was 6 years (range, 3.3-17.5 years); 52% were female. On the basis of immunohistochemical results, 48 patients were assigned to 1 of 4 subgroups: 28 in MGMT-/epidermal growth factor receptor (EGFR)-, 14 in MGMT-/EGFR+, 3 in MGMT+/EGFR-, and 3 in MGMT+/EGFR+. Twenty-three patients had histone mutations in H3F3A, 8 in HIST1H3B, and 3 in HIST1H3C. Enhancing tumor volume was near-significantly different across molecular subgroups (P = .04), after accounting for the false discovery rate. Tumor volume enhancing, median, mode, skewness, and kurtosis ADC T2-FLAIR/T2 were significantly different (P ≤ .048) between patients with H3F3A and HIST1H3B/C mutations.

CONCLUSIONS

MR imaging features including enhancement and ADC histogram parameters are correlated with molecular subgroups and mutations in children with diffuse intrinsic pontine gliomas.

PELP1 is a novel oncogene in gastric tumorigenesis and negatively regulated by miR-15 family microRNAs

BACKGROUD

Gastric cancer (GC) is one of the leading causes of cancer-related death in East Asia and some South American countries, but its mechanism has not been clarified clearly. Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1), a co-regulatory molecule of estrogen receptor α (ER α), is up-regulated in series of cancers such as endometrial carcinoma, ovarian cancer, colorectal cancer, breast cancer, and non-small cell lung cancer. However, PELP1's role in GC is still obscure, and its aberrant expression in cancers also remains to be explained.

METHODS

Immunohistochemical staining and Real-time PCR were used to compare the expression level of PELP1 in GC tissues and adjacent tissues. Western blot was used to detect the expression of PELP1 in cell lines. Kaplan-meier analysis and chi-square test were applied to evaluate the potential of PELP1 to function as a cancer biomarker. RNA interference was used to inhibit PELP1 expression in GC cells, followed by detecting cell proliferation, apoptosis, migration and invasion. Luciferase assay was conducted to validate whether miR-15 family members can directly target PELP1.

RESULTS

In this study, we validated that PELP1 was significantly up-regulated in GC samples and cell lines. It was also demonstrated that the up-regulation of PELP1 was associated with several clinicopathologic features such as tumor diameter (P< 0.001), serum CEA level (P= 0.034), and lymphatic metastasis (P= 0.0009) of GC patients, and its high expression was correlated with shorter disease-free survival and overall survival of the patients. Knockdown of PELP1 remarkably arrested the proliferationï¼ migration and invasion, while promoted apoptosis. We also confirmed that miR-15 family microRNAs, most of which were down-regulated and tumor suppressor in cancers, were posttranscriptional regulators of PELP1.

CONCLUSION

In conclusion, we demonstrated that PELP1 was an oncogene of GC associated with patients' prognosis and miR-15 family members contributed to its aberrant expression in cancers.

Chinese expert group consensus on diagnosis and clinical management of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (MORN) is one of the most devastating complications caused by radiation therapy in the head and neck region. It is characterized by infection and chronic necrosis of the mandible as the main manifestation. Clinically, MORN-related symptoms include swelling, pain, dysphagia, trismus, masticatory or speech disorders, refractory orocutaneous fistula, bone exposure, and even pathological fracture. MORN has become a challenging clinical problem for oral and maxillofacial surgeons to deal with, but thus far, this problem has not been solved due to the lack of widely accepted treatment algorithms or guidelines. Because of the nonexistence of standardized treatment criteria, most clinical treatment against MORN nowadays is largely based on controversial empirical understandings, while recommendations on post-therapeutic evaluations are scarce. Therefore, to further unify and standardize the diagnosis and treatment of MORN, to decrease the huge waste of medical resources, and ultimately, to improve the wellbeing of the patients, the Chinese Society of Oral and Maxillofacial Surgery (CSOMS) convened an expert panel specialized in MORN from 16 domestic medical colleges and affiliated hospitals to discuss the spectrum of diagnosis and and formulate treatment. In addition, consensus recommendations were also revised with a comprehensive literature review of the previous treatment experiences and research pearls. This 'expert consensus statement on diagnosis and clinical management of MORN' is for clinical reference.

A28 RELATIVE RATES OF ULCERATIVE COLITIS TO CROHN’S DISEASE: PARALLEL EPIDEMIOLOGIES IN NEWLY VS. HIGHLY INDUSTRIALIZED COUNTRIES

Background

Inflammatory bowel disease (IBD) first presents in a population as cases of ulcerative colitis (UC) followed by cases of Crohn’s disease (CD). Newly industrialized countries (NIC) show a prallel epidemiology of IBD to highly industrialized countries (HIC) in the previous century; one marker of this is the relative incidence/prevalence rates of UC to CD, which approximates 1 over time.

Aims

Provide evidence for the UC:CD ratio as a proxy for disease penatrance in a population.

Methods

Systematic review of MedLine and Embase for studies reporting incidence or prevalence of UC and CD. Log-linear regression (by region and NIC/HIC [2019 United Nations definitions]) was used to calculate average annual percent change (AAPC) and associated 95% confidence intervals (CI). Data were plotted on an online, interactive map to show trends (link provided).

Results

We extracted data from 218 studies compising population-level data from 69 countries. We found negative AAPCs as the prevalence ratio of UC:CD significantly decreased over time in East Asia, West Asia, North Europe, and South Europe; 6/12 global regions displayed significantly decreasing incidence ratios. No AAPC was found to be significantly increasing (Table 1). When examing HIC/NIC, we found a significant effect of NIC on the UC:CD prevalence ratio after 2000 (AAPC:−3.83;95%CI:−6.28,−1.31) while HIC regions remained stable (AAPC:2.14;95%CI:−1.40,5.82). Looking at all available data, both HICs and NICs show significantly decreasing UC:CD prevalence ratios (HIC:AAPC:−3.72;95% CI:−4.46,−2.97; NIC:AAPC:−2.62;95%CI:−4.13,−1.08).

Conclusions

In some HICs (eg. Canada), the UC:CD incidence ratio was &lt;1 in the earliest available data (1966), explaining the stable AAPC in North America (AAPC:−0.24;95%CI:−1.12,0.65). However, in NICs (eg. Southern Asia), the AAPC is rapidly decreasing (AAPC:−24.68;95%CI:−37.85,−8.71) as areas like Sri Lanka rapidly fall from an incidence ratio of 7.5 (2007) to 2.8 (2012), mimicking trends in IBD epidimeology of HICs in the previous century.

Funding Agencies

None

A234 CLINICAL, ENDOSCOPIC AND HISTOLOGICAL IMPROVEMENT IN COMMON VARIABLE IMMUNODEFICIENCY DISEASE ASSOCIATED ENTEROPATHY WITH VEDOLIZUMAB

Background

Common variable immune deficiency (CVID) can be associated with autoimmune manifestations including enteric inflammation and diarrhea. Systemic immunosuppression used in patients with inflammatory bowel disease (IBD) may be associated with increased risk of infection in CVID.

Aims

We report a patient with CVID associated intestinal enteropathy who underwent clinical, endoscopic and histological improvement after treatment with vedolizumab (IgG1 monoclonal antibody to α4β7 integrin), as well as a concurrent systematic review (SR) of the literature.

Methods

Case report and systematic literature review. We searched EMBASE, Medline, Cochrane CENTRAL, clinialtrials.gov, and the International Clinical Trials Registry Platform without language restriction using key words to identify patients with CVID associated enteropathy treated with vedolizumab. Clinical, endoscopic and histological outcomes were extracted and safety data.

Results

A 32-year-old male presented with weight loss, anemia and hypoalbuminemia on a background of chronic diarrhea and recurrent sinus infections. Serology and genetic testing was not consistent with celiac disease. Pan-endoscopy showed complete villous atrophy in the duodenum and biopsies showed and intraepithelial lymphocytosis (IEL) in the duodenum and terminal ileum. CT abdomen showed pan-enteritis with extensive mesenteric lymphadenopathy which were reactive on lymph node excision, as well as bronchiectasis. Pneumococcal vaccination challenge to assess humoral response confirmed CVID. After suboptimal response with steroids and mercaptopurine, treatment was initiated with vedolizumab 300mg IV at weeks 0, 2, and 6, then 8 weekly. This led to normalization of stool frequency, weight gain as well as endoscopic and histological resolution within 6 months of treatment. The SR yielded 101 studies of which 3 case series were identified reporting a total of 7 patients with CVID. In 5 cases there was clinical improvement, 4 reported endoscopic improvement and 3 patients had histologic improvement. No safety concerns associated with vedolizumab were reported.

Conclusions

Vedolizumab, a selective leucocyte inhibitor to the gut, was able to induce either clinical, endoscopic or histological improvement in 8 published cases in the worldwide literature. Prospective studies are needed to determine whether this treatment could be included in the therapeutic armamentarium for this orphan indication.

Funding Agencies

None

A51 UTILIZING MUCIN-DERIVED SUGARS CONFERS A FITNESS ADVANTAGE TO THE ENTERIC PATHOGEN CITROBACTER RODENTIUM THAT PROMOTES INTESTINAL COLONIZATION

Background

Citrobacter rodentium is an enteric murine pathogen used to model the human diarrheal pathogens. Following inoculation, C. rodentium colonizes the mouse cecum where it expands and ultimately spreads to the distal colon. During this process, C. rodentium has to compete with commensal microbes for available nutrients. Moreover, to spread throughout the gut, and infect the intestinal epithelium, C. rodentium has to cross through, and or dwell within the intestinal mucus layer which is composed of the heavily glycosylated protein Muc2. Muc-2 is glycosylated and coated by 5 distinct terminal sugar residues: galactose, N-acetylgalactosamine, N-acetylglucosamine, fucose, and sialic acid. Many commensal microbes have the ability to cleave and free these sugars from the Muc2 protein, releasing them for their own consumption, however pathogens appear to exploit this process. While studies have indicated that C. rodentium uses these terminal sugar residues as a nutritional source, their relative importance in the pathogenic strategy of C. rodentium (and other gut pathogens) remains unclear

Aims

Investigate the role played by mucin sugar residues in controlling C. rodentium pathogenesis

Methods

Deletions of agaW, nagE, mglB, galP, fucK, and nanT were generated on the chromosome of C. rodentium (Strepr) by overlap extension PCR. Growth assays were performed to examine the growth kinetics of mutants C. rodentium in minimal (M9) media supplemented with one of the 5 mucin sugars or M9 with whole mucin as control. Specific pathogen free (SPF) C57BL/6 mice, or germfree C57BL/6 mice were orally gavaged with wildtype C. rodentium (Strepr) or one of ΔagaW, ΔnagE, ΔmglB, ΔgalP, ΔfucK, or ΔnanT strains. Mice were euthanized at 6 days post-infection, and the cecum, colon, and spleen were collected and histologically scored for pathology and intestinal and systemic bacterial burden. Stool samples were collected throughout the 6 days to quantify C. rodentium burdens

Results

Growth assays confirmed that the specific sugar transporter/kinase mutant C. rodentium strains grew normally when placed in media supplemented with whole mucin, or with most sugars, only showing overt defects in growth when solely supplemented with the sugar for which they were impaired. Several of the C. rodentium mutants including ΔnanT showed overt defects in colonization/infection of SPF C57BL/6 mice, but their pathogenesis was normalized in germfree mice, or in mice treated with the antibiotic streptomycin at each day post-infection. These findings indicate that the impact of mucin sugar utilization on C. rodentium virulence is microbiota-dependent

Conclusions

C. rodentium uses mucin sugars as nutrient source in the mouse gut, and an inability to use these sugars impairs their ability to infect their hosts in a microbiota dependent manner

Funding Agencies

CAG, CCC, CIHR, NRC