KD-Informer: Cuff-Less Continuous Blood Pressure Waveform Estimation Approach Based on Single Photoplethysmography

Ambulatory blood pressure (BP) monitoring plays a critical role in the early prevention and diagnosis of cardiovascular diseases. However, cuff-based inflatable devices cannot be used for continuous BP monitoring, while pulse transit time or multi-parameter-based methods require more bioelectrodes to acquire electrocardiogram signals. Thus, estimating the BP waveforms only based on photoplethysmography (PPG) signals for continuous BP monitoring has essential clinical values. Nevertheless, extracting useful features from raw PPG signals for fine-grained BP waveform estimation is challenging due to the physiological variation and noise interference. For single PPG analysis utilizing deep learning methods, the previous works depend mainly on stacked convolution operation, which ignores the underlying complementary time-dependent information. Thus, this work presents a novel Transformer-based method with knowledge distillation (KD-Informer) for BP waveform estimation. Meanwhile, we integrate the prior information of PPG patterns, selected by a novel backward elimination algorithm, into the knowledge transfer branch of the KD-Informer. With these strategies, the model can effectively capture the discriminative features through a lightweight architecture during the learning process. Then, we further adopt an effective transfer learning technique to demonstrate the excellent generalization capability of the proposed model using two independent multicenter datasets. Specifically, we first fine-tuned the KD-Informer with a large and high-quality dataset (Mindray dataset) and then transferred the pre-trained model to the target domain (MIMIC dataset). The experimental test results on the MIMIC dataset showed that the KD-Informer exhibited an estimation error of 0.02 ± 5.93 mmHg for systolic BP (SBP) and 0.01 ± 3.87 mmHg for diastolic BP (DBP), which complied with the association for the advancement of medical instrumentation (AAMI) standard. These results demonstrate that the KD-Informer has high reliability and elegant robustness to measure continuous BP waveforms.

Objective quantification of the severity of postural tremor based on kinematic parameters: A multi-sensory fusion study

BACKGROUND

Current clinical assessments of essential tremor (ET) are primarily based on expert consultation combined with reviewing patient complaints, physician expertise, and diagnostic experience. Thus, traditional evaluation methods often lead to biased diagnostic results. There is a clinical demand for a method that can objectively quantify the severity of the patient's disease.

METHODS

This study aims to develop an artificial intelligence-aided diagnosis method based on multi-sensory fusion wearables. The experiment relies on a rigorous clinical trial paradigm to collect multi-modal fusion of signals from 98 ET patients. At the same time, three clinicians scored independently, and the consensus score obtained was used as the ground truth for the machine learning models.

RESULTS

Sixty kinematic parameters were extracted from the signals recorded by the nine-axis inertial measurement unit (IMU). The results showed that most of the features obtained by IMU could effectively characterize the severity of the tremors. The accuracy of the optimal model for three tasks classifying five severity levels was 97.71%, 97.54%, and 97.72%, respectively.

CONCLUSIONS

This paper reports the first attempt to combine multiple feature selection and machine learning algorithms for fine-grained automatic quantification of postural tremor in ET patients. The promising results showed the potential of the proposed approach to quantify the severity of ET objectively.

AB1474 LIPIDOMIC PROFILING IDENTIFIES SERUM LIPIDS ASSOCIATED WITH PERSISTENT MULTISITE MUSCULOSKELETAL PAIN

Background

Lipid mediators have been suggested to have a role in pain sensitivity and response; however, longitudinal data on lipid metabolites and persistent multisite musculoskeletal pain (MSMP) are lacking.

Objectives

This study was to identify lipid metabolic markers for persistent MSMP.

Methods

Lipidomic profiling of 807 lipid species was performed on serum samples of 536 participants from a cohort study. MSMP was measured by a questionnaire and defined as painful sites ≥4. Persistent MSMP was defined as having MSMP at every visit. Logistic regression was used with adjustment for potential confounders. The Benjamini Hochberg method was used to control for multiple testing.

Results

A total of 530 samples with 807 lipid metabolites passed quality control. Mean age at baseline was 61.54±6.57 years and 50% were females. One hundred and twelve (21%) of the participants had persistent MSMP. Persistent MSMP was significantly associated with lower levels of monohexosylceramide (HexCer)(d18:1/22:0 and d18:1/24:0), acylcarnitine (AC)(26:0) and lysophosphatidylcholine (LPC)(18:1 [sn1], 18:2 [sn1], 18:2 [sn2], and 15-MHDA[sn1] [104_sn1]) after controlling for multiple testing. After adjustment for age, sex, body mass index, diabetes status, and physical activity, HexCer(d18:1/22:0 and d18:1/24:0) and LPC(18:1 [sn1] and 15-MHDA [sn1] [104_sn1]) were significantly associated with persistent MSMP [Odds Ratio (OR) ranging from 0.24 - 0.32]. Two lipid classes -- HexCer and LPC were negatively associated with persistent MSMP after adjustment for covariates (OR=0.19 and 0.21, respectively).

Conclusion

This study identified four novel lipid signatures of persistent MSMP, suggesting that lipid metabolism is involved in the pathogenesis of persistent pain.

Disclosure of Interests

None declared

[All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ]

Objective: To investigate the surgical technology and clinical efficacy of using the all-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ. Methods: The clinical data of 33 patients (33 feet) with intra-articular displaced calcaneal fractures treated by modified all-inside arthroscopic from March 2017 to March 2019 at Department of Orthopedics,Xuzhou Central Hospital were retrospectively analyzed.There were 19 male patients,and 14 female patients,aged (32.6±11.3) years(range:20 to 55 years). According to the Sanders classification,there were 12 cases of type Ⅱ and 21 cases of type Ⅲ. The duration from injury to surgery was (101.2±32.1) hours(range:6 to 140 hours).The preoperative visual analogue scale (VAS) was 6.4±2.9 (range: 4 to 8); The preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale and the SF-36 score was 63.3±11.8 (range:50 to 75) and 94.8±9.1 (range:70 to 105) respectively.All the patients were managed with the all-side subtalar arthroscopy through three portals combined with rafting screws technique.The incision healing,reduction of fracture,and fracture healing were recorded.The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were used to assess the pain and functional outcomes.Repeated-measurement was used to compare the scores before and after surgery. Results: The time of operation was (69.7±10.4) minutes (range:40 to 110 minutes). All patients did not undergo bone grafting.The incision healed in one stage without complications of skin sensory and peroneal tendon injury.All patients were followed up for 24 months.At the last follow-up,all the patients were satisfied with the hindfoot alignment,function,and hindfoot appearance.Postoperative calcaneal imaging indicators (calcaneal length,calcaneal width,calcaneal height,Bohler angle and Gissane angle) were significantly improved compared with those before surgery (P<0.01).There was no statistically significant difference in the imaging indexes of calcaneus at 1 day,1 year and 2 years after surgery,indicating no loss of fracture reduction (all P>0.05).The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were 1.5±0.4 (range: 0 to 2),94.0±6.5 (range:90 to 100),and 119.1±7.2 (range:105 to 130),respectively,which were better than those before surgery (all P>0.05).According to the AOFAS scoring system,27 cases were excellent,4 cases were good, 2 cases were fair,and the excellent and good rate was 94.0%. Conclusion: All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ provides precise reduction,reliable fixation,satisfactory function and limited complications,which is an alternative method.

A review of advances in imaging methodology in fluorescence molecular tomography

Objective. Fluorescence molecular tomography (FMT) is a promising non-invasive optical molecular imaging technology with strong specificity and sensitivity that has great potential for preclinical and clinical studies in tumor diagnosis, drug development and therapeutic evaluation. However, the strong scattering of photons and insufficient surface measurements make it very challenging to improve the quality of FMT image reconstruction and its practical application for early tumor detection. Therefore, continuous efforts have been made to explore more effective approaches or solutions in the pursuit of high-quality FMT reconstructions. Approach. This review takes a comprehensive overview of advances in imaging methodology for FMT, mainly focusing on two critical issues in FMT reconstructions: improving the accuracy of solving the forward physical model and mitigating the ill-posed nature of the inverse problem from a methodological point of view. More importantly, numerous impressive and practical strategies and methods for improving the quality of FMT reconstruction are summarized. Notably, deep learning methods are discussed in detail to illustrate their advantages in promoting the imaging performance of FMT thanks to large datasets, the emergence of optimized algorithms and the application of innovative networks. Main results. The results demonstrate that the imaging quality of FMT can be effectively promoted by improving the accuracy of optical parameter modeling, combined with prior knowledge, and reducing dimensionality. In addition, the traditional regularization-based methods and deep neural network-based methods, especially end-to-end deep networks, can enormously alleviate the ill-posedness of the inverse problem and improve the quality of FMT image reconstruction. Significance. This review aims to illustrate a variety of effective and practical methods for the reconstruction of FMT images that may benefit future research. Furthermore, it may provide some valuable research ideas and directions for FMT in the future, and could promote, to a certain extent, the development of FMT and other methods of optical tomography.

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

Longitudinal Changes and Recovery in Heart Rate Variability of Young Healthy Subjects When Exposure to a Hypobaric Hypoxic Environment

Background: The autonomic nervous system (ANS) is crucial for acclimatization. Investigating the responses of acute exposure to a hypoxic environment may provide some knowledge of the cardiopulmonary system’s adjustment mechanism.

Objective: The present study investigates the longitudinal changes and recovery in heart rate variability (HRV) in a young healthy population when exposed to a simulated plateau environment.

Methods: The study followed a strict experimental paradigm in which physiological signals were collected from 33 healthy college students (26 ± 2 years, 171 cm ± 7 cm, 64 ± 11 kg) using a medical-grade wearable device. The subjects were asked to sit in normoxic (approximately 101 kPa) and hypoxic (4,000 m above sea level, about 62 kPa) environments. The whole experimental process was divided into four stable resting measurement segments in chronological order to analyze the longitudinal changes of physical stress and recovery phases. Seventy-six time-domain, frequency-domain, and non-linear indicators characterizing rhythm variability were analyzed in the four groups.

Results: Compared to normobaric normoxia, participants in hypobaric hypoxia had significantly lower HRV time-domain metrics, such as RMSSD, MeanNN, and MedianNN (p &lt; 0.01), substantially higher frequency domain metrics such as LF/HF ratio (p &lt; 0.05), significantly lower Poincaré plot parameters such as SD1/SD2 ratio and other Poincaré plot parameters are reduced considerably (p &lt; 0.01), and Refined Composite Multi-Scale Entropy (RCMSE) curves are reduced significantly (p &lt; 0.01).

Conclusion: The present study shows that elevated heart rates, sympathetic activation, and reduced overall complexity were observed in healthy subjects exposed to a hypobaric and hypoxic environment. Moreover, the results indicated that Multiscale Entropy (MSE) analysis of RR interval series could characterize the degree of minor physiological changes. This novel index of HRV can better explain changes in the human ANS.

Wettability Transition of the Picosecond Laser-Ablated 304 Stainless-Steel Surface via Low-Vacuum Heat Treatment

Inspired by natural creatures, superhydrophobic surfaces with various adhesion behaviors have attracted significant scientific interest. In this study, by controlling the laser fluence, the scanning times, and the subsequent cleaning method, microcolumn arrays with different morphologies were fabricated on 304 stainless-steel surfaces using picosecond laser direct writing. To achieve wettability transition, the laser-processed samples were then subjected to heat treatments (120 °C) in air and in a low vacuum environment (6 kPa). The results show that after heat treatment in different environments and with various time lengths, the laser-processed surfaces become hydrophobic surfaces with different adhesion properties. It is worth noting that while surfaces heat-treated in air exhibit weak wettability transition potential and high adhesion, the surfaces heat-treated in a low vacuum environment present superhydrophobic and low adhesion properties with a minimum sliding angle of about 3.14°. Moreover, the low-vacuum heat-treated surfaces retain good superhydrophobic properties after 1 month of observation as well as an abrasion test. These transitions in hydrophobic behavior and adhesion properties may be mainly attributed to the heat treatment-induced (in the air or in a low vacuum environment) redistribution of surface compounds and the microstructure-induced alternation of the solid-liquid contact state. By controlling the laser processing parameters and the heat treatment time and environment, stable wettability transition and flexible adhesion control of stainless steel can be easily achieved.

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.

Global hybrid multi-scale convolutional network for accurate and robust detection of atrial fibrillation using single-lead ECG recordings

BACKGROUND AND OBJECTIVE

Atrial fibrillation (AF) is the most common persistent cardiac arrhythmia in clinical practice, and its accurate screening is of great significance to avoid cardiovascular diseases (CVDs). Electrocardiogram (ECG) is considered to be the most commonly used technique for detecting AF abnormalities. However, previous ECG-based deep learning algorithms did not take into account the complementary nature of inter-layer information, which may lead to insufficient AF screening. This study reports the first attempt to use hybrid multi-scale information in a global space for accurate and robust AF detection.

METHODS

We propose a novel deep learning classification method, namely, global hybrid multi-scale convolutional neural network (i.e., GH-MS-CNN), to implement binary classification for AF detection. Unlike previous deep learning methods in AF detection, an ingenious hybrid multi-scale convolution (HMSC) module, for the advantage of automatically aggregating different types of complementary inter-layer multi-scale features in the global space, is introduced into all dense blocks of the GH-MS-CNN model to implement sufficient feature extraction, and achieve much better overall classification performance.

RESULTS

The proposed GH-MS-CNN method has been fully validated on the CPSC 2018 database and tested on the independent PhysioNet 2017 database. The experimental results show that the global and hybrid multi-scale information has tremendous advantages over local and single-type multi-scale information in AF screening. Furthermore, the proposed GH-MS-CNN method outperforms the state-of-the-art methods and achieves the best classification performance with an accuracy of 0.9984, a precision of 0.9989, a sensitivity of 0.9965, a specificity of 0.9998 and an F1 score of 0.9954. In addition, the proposed method has achieved comparable and considerable generalization capability on the PhysioNet 2017 database.

CONCLUSIONS

The proposed GH-MS-CNN method has promising capabilities and great advantages in accurate and robust AF detection. It is assumed that this research has made significant improvements in AF screening and has great potential for long-term monitoring of wearable devices.

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.

Assessing Electrocardiogram and Respiratory Signal Quality of a Wearable Device (SensEcho): Semisupervised Machine Learning-Based Validation Study

Background

With the development and promotion of wearable devices and their mobile health (mHealth) apps, physiological signals have become a research hotspot. However, noise is complex in signals obtained from daily lives, making it difficult to analyze the signals automatically and resulting in a high false alarm rate. At present, screening out the high-quality segments of the signals from huge-volume data with few labels remains a problem. Signal quality assessment (SQA) is essential and is able to advance the valuable information mining of signals.

Objective

The aims of this study were to design an SQA algorithm based on the unsupervised isolation forest model to classify the signal quality into 3 grades: good, acceptable, and unacceptable; validate the algorithm on labeled data sets; and apply the algorithm on real-world data to evaluate its efficacy.

Methods

Data used in this study were collected by a wearable device (SensEcho) from healthy individuals and patients. The observation windows for electrocardiogram (ECG) and respiratory signals were 10 and 30 seconds, respectively. In the experimental procedure, the unlabeled training set was used to train the models. The validation and test sets were labeled according to preset criteria and used to evaluate the classification performance quantitatively. The validation set consisted of 3460 and 2086 windows of ECG and respiratory signals, respectively, whereas the test set was made up of 4686 and 3341 windows of signals, respectively. The algorithm was also compared with self-organizing maps (SOMs) and 4 classic supervised models (logistic regression, random forest, support vector machine, and extreme gradient boosting). One case validation was illustrated to show the application effect. The algorithm was then applied to 1144 cases of ECG signals collected from patients and the detected arrhythmia false alarms were calculated.

Results

The quantitative results showed that the ECG SQA model achieved 94.97% and 95.58% accuracy on the validation and test sets, respectively, whereas the respiratory SQA model achieved 81.06% and 86.20% accuracy on the validation and test sets, respectively. The algorithm was superior to SOM and achieved moderate performance when compared with the supervised models. The example case showed that the algorithm was able to correctly classify the signal quality even when there were complex pathological changes in the signals. The algorithm application results indicated that some specific types of arrhythmia false alarms such as tachycardia, atrial premature beat, and ventricular premature beat could be significantly reduced with the help of the algorithm.

Conclusions

This study verified the feasibility of applying the anomaly detection unsupervised model to SQA. The application scenarios include reducing the false alarm rate of the device and selecting signal segments that can be used for further research.

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.

[Research progress on wearable physiological parameter monitoring and its clinical applications]

Wearable physiological parameter monitoring devices play an increasingly important role in daily health monitoring and disease diagnosis/treatment due to their continuous dynamic and low physiological/psychological load characteristics. After decades of development, wearable technologies have gradually matured, and research has expanded to clinical applications. This paper reviews the research progress of wearable physiological parameter monitoring technology and its clinical applications. Firstly, it introduces wearable physiological monitoring technology's research progress in terms of sensing technology and data processing and analysis. Then, it analyzes the monitoring physiological parameters and principles of current medical-grade wearable devices and proposes three specific directions of clinical application research: 1) real-time monitoring and predictive warning, 2) disease assessment and differential diagnosis, and 3) rehabilitation training and precision medicine. Finally, the challenges and response strategies of wearable physiological monitoring technology in the biomedical field are discussed, highlighting its clinical application value and clinical application mode to provide helpful reference information for the research of wearable technology-related fields.

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.