The economic impacts of COVID-19 and city lockdown: Early evidence from China

As the first major developing country heavily struck by the COVID-19 pandemic, China adopted the world's most stringent lockdown interventions to contain the virus spread. Using macro- and micro-level data, this paper shows that both the pandemic and lockdown policies have had negative and significant impacts on the economy. Gross regional product (GRP) fell by 9.5 and 0.3 percentage points in cities with and without lockdown interventions, respectively. These impacts represent a dramatic recession from China's average growth of 6.74% before the pandemic. The results indicate that lockdown explains 2.8 percentage points of the GDP loss. We also document significant spill-over effects of the pandemic in adjacent areas but no such effects of lockdown. Reduced labor mobility, land supply, and entrepreneurship are among the most significant mechanisms underpinning the impacts of the pandemic and lockdown. Cities with higher share of secondary industry, higher traffic intensity, lower population density, lower internet access, and lower fiscal capacity suffered more. However, these cities seem to have recovered well from the recession and quickly closed the economic gap in the aftermath of the pandemic and city lockdown. Our findings have broader implications for the global interventions in pandemic containment.

[The status and influencing factors of presenteeism among clinical nurses: a systematic review]

Objective: To systematically review the status and factors influencing presenteeism among clinical nurses. Methods: In December 2021, CNKI, CBM, Wanfang, VIP, Web of Science, PubMed, Embase, The Cochrane Library, CINAHL, PsyclNFO and other databases were electronically searched to cross sectional studies on the current situation and factors influencing the occurrence of presenteeism among clinical nurses. The search terms mainly included presenteeism, sick at work, Stanford Presenteeism Scale, nurse, level, risk factor, influence, et al. And the search time was from the establishment of the database to November 30, 2021. Literature screening, data extraction and evaluation of the risk of bias in the included literature were done independently by two researchers, and meta-analysis was performed using Stata 15.1 software. Results: A total of 29 studies involving 13 535 clinical nurses were included.The results of the meta-analysis showed that the score of presenteeism was 17.99 [95% CI (17.02-18.95), P =0.000]. Subgroup analysis showed that presenteeism scores were higher in articles published before 2020 (ES=19.28, 95%CI: 18.41-20.15, P=0.000) and in the group of nurses aged 36 to 40 years (ES=19.27, 95%CI: 17.35~21.19, P=0.000), female (ES= 17.04, 95%CI: 14.70-19.39, P=0.000), secondary school education (ES=21.01, 95%CI: 17.76-24.26, P= 0.007), married (ES=17.49, 95%CI: 15.13-19.85, P=0.000), working for 5 to 10 years (ES=17.78, 95%CI: 16.54-19.02, P=0.000), contract (ES=17.05, 95%CI: 15.23-18.87, P=0.000), working in pediatrics (ES= 16.65, 95% CI: 15.31-17.99, P=0.000) and European region (ES =21.21, 95% CI: 20.50-21.93, P=0.000) . Conclusion: Current evidence suggests that clinical nurses are at high risk of presenteeism, which is affected by variety of factors. The managers should pay attention to the physical and mental health of nurses, identify high-risk factors as early as possible and take measures to reduce the occurrence of presenteeism and improve the quality of nursing.

A180 PLACEBO RATES IN MICROSCOPIC COLITIS RANDOMIZED TRIALS: APPLICATIONS FOR FUTURE DRUG DEVELOPMENT USING A HISTORICAL CONTROL ARM

Background

There remains a need to develop effective medical therapies for patients with microscopic colitis (MC) who do not respond, are intolerant, or relapse on budesonide. Conducting randomized trials in MC is logistically and ethically challenging: budesonide is highly effective, and therefore, some institutional review boards have not allowed trials that randomize MC patients to placebo. However, comparing an investigational drug to budesonide is statistically infeasible: powering a non-inferiority study against a budesonide comparator arm with 90% power for a 10% non-inferiority margin would require over 700 subjects, yet fewer than 400 patients have been randomized in all historical MC trials. Therefore, alternative trial designs should be explored in MC, including the use of a historical control arm.

Purpose

To conduct a systematic review and meta-analysis to determine the proportion of placebo responders in MC trials that will inform future trials using a historical placebo comparator, and evaluate factors associated with placebo response.

Method

EMBASE, MEDLINE, and CENTRAL were searched from inception to January 7, 2022, and supplemented with conference abstracts to identify randomized controlled trials (RCTs) using a placebo comparator in adult patients with confirmed MC (either lymphocytic, collagenous, or mixed populations but excluding incomplete MC). The proportion of clinical and histologic responders in the placebo arms were pooled using random-effect models, statistical heterogeneity was evaluated using the I2 method, and the Freeman-Tukey double arcsine transformation was used to compute 95% confidence intervals (CI) using the score statistic and exact binomial method. All analyses were conducted in Stata 17.0.

Result(s)

Twelve placebo controlled RCTs were included, evaluating a total of 391 patients (163 randomized to placebo). The pooled placebo clinical response rate was 24.4% [95% CI 12.4%, 38.4%] (Figure 1), with substantial heterogeneity (I2=60.8%, p<0.01). The pooled histologic response rate was 19.9% [95% CI: 5.3%, 39.0%], with substantial heterogeneity (I2=66.4%, p<0.01). Subgroup analysis demonstrated higher placebo responses in lymphocytic colitis (39.9% [95% CI: 23.9%, 56.7%]) compared to collagenous colitis (19.8% [95% CI: 5.9%, 37.8%]), but not by allowance of baseline anti-diarrheals. Leave-one-out meta-analysis showed a reduction in heterogeneity after removal of Miehlke et al. 2014 (placebo response 21.0% [95% CI: 11.5%, 32.1%], I2=28.6%, p=0.17).

Image

Conclusion(s)

Approximately 1 in 4 patients in MC trials will respond clinically to placebo and 1 in 5 will demonstrate a histologic response, although with substantial heterogeneity. T his highlights the need for standardized outcome definitions in MC trials and can serve to inform a Bayesian prior estimate for future trials that may consider using a historical placebo comparator.

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None

Disclosure of Interest

P. Hamilton: None Declared, K. Buhler: None Declared, G. Kaplan Grant / Research support from: Ferring, Janssen, AbbVie, GlaxoSmith Kline, Merck, and Shire, Consultant of: AbbVie, Janssen, Pfizer, Amgen, Takeda, and Gilead, C. Lu Consultant of: Abbvie, Janssen, Ferring, and Takeda, Speakers bureau of: Janssen and Abbvie, C. Seow Consultant of: Advisory Boards: Janssen, Abbvie, Takeda, Ferring, Shire, Pfizer, Sandoz, Pharmascience, Fresenius Kabi, Amgen, Speakers bureau of: Janssen, Abbvie, Takeda, Ferring, Shire, Pfizer, Pharmascience, K. Novak Grant / Research support from: AbbVie and Janssen, Consultant of: Advisory board fees from AbbVie, Janssen, Pfizer, Ferring, and Takeda, speaker’s fees from AbbVie, Janssen, and Pfizer, R. Panaccione Consultant of: Abbott, AbbVie, Alimentiv (formerly Robarts), Amgen, Arena Pharmaceuticals, AstraZeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Celltrion, Cosmos Pharmaceuticals, Eisai, Elan, Eli Lilly, Ferring, Galapagos, Fresenius Kabi, Genentech, Gilead Sciences, Glaxo-Smith Kline, JAMP Bio, Janssen, Merck, Mylan, Novartis, Oppilan Pharma, Organon, Pandion Pharma, Pendopharm, Pfizer, Progenity, Protagonist Therapeutics, Roche, Sandoz, Satisfai Health, Shire, Sublimity Therapeutics, Takeda Pharmaceuticals, Theravance Biopharma, Trellus, Viatris, UCB. Advisory Boards for: AbbVie, Alimentiv (formerly Robarts), Amgen, Arena Pharmaceuticals, AstraZeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Ferring, Fresenius Kabi, Genentech, Gilead Sciences, Glaxo-Smith Kline, JAMP Bio, Janssen, Merck, Mylan, Novartis, Oppilan Pharma, Organon, Pandion Pharma, Pfizer, Progenity, Protagonist Therapeutics, Roche, SandozShire, Sublimity Therapeutics, Takeda Pharmaceuticals, Speakers bureau of: AbbVie, Amgen, Arena Pharmaceuticals, Bristol-Myers Squibb, Celgene, Eli Lilly, Ferring, Fresenius Kabi, Gilead Sciences, Janssen, Merck, Organon, Pfizer, Roche, Sandoz, Shire, Takeda Pharmaceuticals, C. Ma Grant / Research support from: Ferring, Pfizer, Consultant of: AbbVie, Alimentiv, American College of Gastroenterology, Amgen, AVIR Pharma Inc, BioJAMP, Bristol Myers Squibb, Celltrion, Ferring, Fresenius Kabi, Janssen, McKesson, Mylan, Sanofi/Regeneron, Takeda, Pendopharm, Pfizer, Roche, Speakers bureau of: : AbbVie, Amgen, AVIR Pharma Inc, Alimentiv, Bristol Myers Squibb, Ferring, Fresenius Kabi, Janssen, Takeda, Pendopharm, and Pfizer

A192 EFFICACY OF USTEKINUMAB IN SMALL BOWEL STRICTURES OF FIBROSTENOTIC CROHN'S DISEASE AS ASSESSED BY INTESTINAL ULTRASOUND

Background

Small bowel Crohn’s disease (CD) strictures can lead to debilitating obstructive symptoms and the deterioration of quality of life. Imaging modalities such as intestinal ultrasound (IUS) are invaluable in the diagnosis of strictures. The use of IUS in CD is rapidly growing, is cost-effective, easily repeatable, and similar in accuracy to magnetic resonance enterography. Evidence for medical management of fibrostenotic CD has been limited to anti-tumor necrosis factor biologics. Studies on the efficacy of other biologic therapies for strictures such as ustekinumab, a p40/interleukin 12 and 23 inhibitor, are lacking.

Purpose

The objective of this study was to evaluate the efficacy of ustekinumab in the treatment of small bowel strictures on IUS.

Method

This retrospective cohort study evaluated the IUS changes of terminal ileal (TI) CD strictures at baseline and 12 months following ustekinumab initiation from 2016 to 2020 at a single tertiary care center. Strictures identified were defined as 1) increased bowel wall thickness (BWT) > 3mm, 2) narrowed luminal apposition, and 3) presence of pre-stenotic dilation (PSD) or the inability to pass the colonoscope through the narrowed area. Changes in sonographic parameters (BWT, luminal size, PSD, length, hyperemia, inflammatory fat, dysfunctional peristalsis) were recorded at baseline prior to initiation of ustekinumab and compared 12 months after treatment. Differences from baseline to 12 months were paired within-person and statistical analysis was performed using paired T-tests for continuous variables and McNemar’s test for categorical variables.

Result(s)

Of the 18 patients identified, 55% (n = 10) were male, median age was 49 years (Q1-Q3: 33-63 years) at initial scan, with median CD duration of 10 years (Q1-Q3: 8-20 years). The majority of TI strictures were surgically naïve (67%, n = 12). Between pre- and 12-month post ustekinumab therapy scans, there was significant improvement in BWT [8.2 mm vs 7.2 mm, p = 0.048], however there was no significant difference in the presence of peri-enteric inflammatory fat (p = 0.10), mean stricture length (17.7 vs 21.7 cm, p = 0.18), and mean stricture lumen diameter (3.3 mm vs 2.7 mm, p = 0.44) (Table 1). There was also no significant difference in the presence of stricture-associated peri-enteric fat (89% vs 67%, p = 0.10), stricture-associated hyperemia (83% vs 89%, p = 0.65) or dysfunctional peristalsis (50% vs 61%, p = 0.41) (Table 1).

Image

Conclusion(s)

Our study is the first to report the efficacy of ustekinumab in small bowel CD strictures using IUS at baseline and 12 months. This study shows that although ustekinumab leads to improvement in overall sonographic appearance of bowel thickness, it does not improve luminal narrowing nor PSD, two hallmark criteria of fibrostenosis. More extensive studies with larger sample sizes evaluating ustekinumab, or combination therapies, are required to identify their role in stricturing CD.

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None

Disclosure of Interest

None Declared

Risk factors analysis and establishment of predictive nomogram of extranodal B-cell lymphoma of mucosal-associated lymphoid tissue

PURPOSE

The role of radiation therapy in mucosa-associated lymphoid tissue (MALT) lymphoma is poorly defined. The objective of this study was to explore the factors associated with the performance of radiotherapy and to assess its prognostic impact in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with MALT lymphoma diagnosed between 1992 and 2017 were identified in the US Surveillance, Epidemiology, and End Results database (SEER). Factors associated with the delivery of radiotherapy were assessed by chi-square test. Overall survival (OS) and lymphoma-specific survival (LSS) were compared between patients with and without radiotherapy, using Cox proportional hazard regression models, in patients with early stage as well as those with advanced stage.

RESULTS

Of the 10,344 patients identified with a diagnosis of MALT lymphoma, 33.6% had received radiotherapy; this rate was 38.9% for stage I/II patients and 12.0% for stage III/IV patients, respectively. Older patients and those who already received primary surgery or chemotherapy had a significantly lower rate of receiving radiotherapy, regardless of lymphoma stage. After univariate and multivariate analysis, radiotherapy was associated with improved OS and LSS in patients with stage I/II (HR=0.71 [0.65-0.78]) and (HR=0.66 [0.59-0.74]), respectively, but not in patients with stage III/IV (HR=1.01 [0.80-1.26]) and (HR=0.93 [0.67-1.29]). The nomogram built from the significant prognostic factors associated with overall survival of stage I/II patients had a good concordance (C-index=0.749±0.002).

CONCLUSION

This cohort study shows that radiotherapy is significantly associated with a better prognosis in patients with early but not advanced MALT lymphoma. Prospective studies are needed to confirm the prognostic impact of radiotherapy in patients with MALT lymphoma.

A170 ADVERSE EVENTS & SEROLOGICAL RESPONSES FOLLOWING SARS-COV-2 VACCINATION IN INDIVIDUALS WITH INFLAMMATORY BOWEL DISEASE

Background

The rapid development and distribution of SARS-CoV-2 vaccines has raised concerns surrounding vaccine safety in immunocompromised populations, such as those with inflammatory bowel disease (IBD).

Purpose

We described adverse events (AEs) following SARS-CoV-2 vaccination in those with IBD and determined relationships between AEs to post-vaccination antibody titres.

Method

Individuals with IBD from a prospective cohort in Calgary, Canada (n=670) who received a 1^st, 2^nd, 3^rd, and/or 4^th dose of a SARS-CoV-2 vaccine (Pfizer-BioNTech, Moderna, and/or AstraZeneca) were interviewed via telephone for AEs using the Adverse Events Following Immunization form. Subsequently, we assessed injection site reaction as a specific AE outcome. Multivariable logistic regression models were used to assess the association between anti-SARS-CoV-2 spike protein antibody (anti-S) levels within 1–12 weeks of vaccination and injection site reaction following 1st, 2nd, and 3rd dose vaccination. Models were adjusted for age, sex, IBD type, IBD medications, vaccine type, and prior COVID-19 infection. Additionally, we evaluated the risk of flare of IBD within 30 days of vaccination via chart review.

Result(s)

Table 1 describes AEs in individuals with IBD following 1^st dose (n=331), 2^nd dose (n=331), 3^rd dose (n=195), and 4^th dose (n=100) of a SARS-CoV-2 vaccine. AEs were reported in 83.3% of participants after 1^st dose, 79.1% after 2^nd dose, 77.4% after 3^rd dose, and 67.0% after 4^th dose. Injection site reaction (pain, redness, etc.) was the most common AE (50.8% of AEs), with fatigue and malaise (18.1%), headache and migraine (8.6%), musculoskeletal discomfort (8.2%), and fever and chills (6.5%) also commonly reported. Multivariable logistic regression determined no associations between anti-S concentration and injection site reaction for all doses. Age above 65 years was associated with decreased injection site reaction following 1^st and 3^rd doses, while female sex and mRNA vaccine type were associated with increased injection site reaction following 1^st and 2^nd doses. Prior COVID-19 infection, IBD type, and medication class were not associated with injection site reaction with any dose. Only one participant was diagnosed with a severe AE requiring hospitalization: Immune thrombocytopenic purpura (ITP) following 2^nd dose of a Pfizer vaccination. No cases of IBD flare occurred within 30 days of vaccination.

Image

Conclusion(s)

AEs following SARS-CoV-2 vaccination are generally mild and become less common with each consecutive dose. Antibody levels following each dose of the vaccine were not associated with injection site reactions. Females, those under 65 years of age, and those administered mRNA vaccines were more likely to experience an injection site reaction. Prior COVID-19 infection, IBD type, and IBD medication class did not predict injection site reactions. Vaccination was not associated with IBD flare within 30 days of vaccination.

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Other

Please indicate your source of funding;

Helmsley

Disclosure of Interest

A. Markovinovic: None Declared, M. Herauf: None Declared, J. Quan: None Declared, L. Hracs: None Declared, J. Windsor: None Declared, N. Sharifi: None Declared, S. Coward: None Declared, L. Caplan: None Declared, J. Gorospe: None Declared, C. Ma Grant / Research support from: Ferring, Pfizer, , Consultant of: AbbVie, Alimentiv, Amgen, Ferring, Pfizer, Takeda, , Speakers bureau of: AbbVie, Alimentiv, Amgen, Ferring, Pfizer, Takeda, R. Panaccione Grant / Research support from: AbbVie, Ferring, Janssen, Pfizer, Takeda, Consultant of: Abbott, AbbVie, Alimentiv, Amgen, Arena, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Cosmos Pharmaceuticals, Eisai, Elan, Eli Lilly, Ferring, Galapagos, Genentech, Gilead Sciences, GlaxoSmithKline, Janssen, Merck, Mylan, Oppilan Pharma, Pandion Therapeutics, Pandion Pharma, Pfizer, Progenity, Protagonist, Roche, Sandoz, Satisfai Health, Schering-Plough, Shire, Sublimity Therapeutics, Takeda, Theravance, UCB, Speakers bureau of: AbbVie, Arena, Celgene, Eli Lilly, Ferring, Gilead Sciences, Janssen, Merck, Pfizer, Roche, Sandoz, Shire, Takeda, R. Ingram: None Declared, J. Kanji: None Declared, G. Tipples: None Declared, J. Holodinsky: None Declared, C. Berstein Grant / Research support from: AbbVie, Amgen, Janssen, Pfizer, Takeda, Speakers bureau of: AbbVie, Janssen, Pfizer, Takeda, D. Mahoney: None Declared, S. Bernatsky: None Declared, E. Benchimol: None Declared, G. Kaplan Grant / Research support from: Ferring, Speakers bureau of: AbbVie, Janssen, Pfizer

A107 VISCERAL ADIPOSE TISSUE VOLUME DIFFERENTIATES BETWEEN FIBROSTENOTIC AND INFLAMMATORY CROHN’S DISEASE

Background

Creeping fat, a form of visceral adipose tissue (VAT) that wraps the intestinal wall, influences the formation of Crohn’s disease (CD) strictures. The degree of fat wrapping from intestinal stricture resections is correlated with the extent of chronic inflammation, fibrosis, stricture formation, and response to biologic therapy. VAT and subcutaneous adipose tissue (SAT) ratios from CTE (computed tomography) scans are elevated in CD strictures. However, the definition of strictures in these studies has been poorly defined and not included current well-recognized criteria: 1) bowel wall thickness (BWT), 2) narrowed luminal diameter, and 3) pre-stenotic dilation. (PSD).

Purpose

The objective of this pilot study was to assess the relationship of 2D and 3D VAT:SAT ratios with CT stricture parameters in patients with terminal ileal (TI) CD strictures.

Method

2D VAT:SAT ratios from CT’s of CD patients with TI strictures defined as increased BWT, narrowed luminal diameter (< 50% relative to normal adjacent distended loop), and PSD greater than the stricture diameter were retrospectively obtained from a database and chart review. CT’s from fibrostenotic CD patients were sex and BMI matched to patients with only TI inflammatory behaviour. Patient demographics, medication, smoking, and surgical history were also obtained. Analyses were adjusted for age, sex, and BMI covariates. Unpaired t-tests and multi-variable logistic regression analyses were conducted.

Result(s)

Twenty-eight patients with stricturing CD had a significantly greater mean VAT:SAT volume ratio than 29 non-stricturing CD (41.5 cm³ vs 34.2 cm³, p=0.03). Thirty-six percent (10/28) of CD stricture patients had prior ileocolic resection with a mean disease duration of 13.5 years (range 0-48). The median ileal BWT (7.0 mm, range 4.0-13.0 mm) for the stricturing group was significantly greater than those with inflammatory behaviour (BWT 2.0 mm, p<0.0001). The median luminal diameter and PSD for the stricture group was 2.0 mm (range 0 - 14.0 mm), and 3.0 cm (range 1.0 - 7.3 cm), respectively.

Image

Conclusion(s)

Fibrostenotic TI CD patients have increased VAT:SAT ratios in comparison to those with only inflammatory behaviour. These pilot VAT:SAT results provide an initial foundation for further studies to assess its predictive role in responsiveness of medical or surgical therapies in stricturing CD.

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None

Disclosure of Interest

None Declared

A193 DEMOGRAPHIC, SOCIAL AND OCCUPATIONAL FACTORS THAT PREVENTED EXPOSURE TO SARS-COV-2 IN INFLAMMATORY BOWEL DISEASE PATIENTS DURING THE COVID-19 PANDEMIC: A PROSPECTIVE COHORT STUDY

Background

The COVID-19 pandemic caused by the SARS-CoV-2 virus is a rapidly evolving public health emergency in which mundane behaviors such as grocery shopping or restaurant dining are considered high-risk for some, such as persons with inflammatory bowel disease (IBD) who are often immunodeficient due to medications. Research on the behavioral exposures experienced by populations with IBD during the COVID-19 pandemic are lacking.

Purpose

We aim to better understand how the behaviors of persons with IBD are associated with COVID-19 diagnoses.

Method

We conducted a prospective serosurveillance cohort study in Calgary to assess exposure to SARS-CoV-2 from Nov. 1, 2020 to Aug. 8, 2022 in 485 individuals with IBD. A diagnosis of SARS-CoV-2 was defined as a molecular-confirmed PCR test, a self-report home antigen test, or a positive nucleocapsid antibody level. Participants completed a self-report electronic questionnaire on social and occupational risk activities stratified across two time periods: Jan. 2020 to Mar. 2020 (before lockdown) and post-Jun. 2020 (post lockdown). Univariate analyses (χ² and Fischer’s exact if n≤5) were performed on social activities that occurred following the lockdown among those with IBD who were and were not diagnosed with COVID-19. Occupational exposures were compared across essential workers (EW) (i.e., frontline workers at high risk of COVID) and non-EWs.

Result(s)

Overall, 37.5% (n=182) of our cohort was diagnosed with COVID-19. Seniors were less likely to be infected with COVID-19 (22.7%) compared to those under the age of 65 (40.8%) (p=0.002). A greater proportion of females (42.6 %) compared to males (32.5%) were COVID positive (p=0.02). Those with Crohn’s disease (38.3%) were as likely to test positive for COVID-19 as those with ulcerative colitis (36%) (p=0.65). COVID positive patients were less likely to have 4 vaccine doses (28.5%) compared to those who tested negative (71.5%) (p=0.4).

Statistically significant decreases (p<0.001) in engagement post-Jun. 2020 were observed for: bar use (11.6% to 2.1%), visiting a friend (44.5% to 15.2%), having visitors over (38.7% to 12.1%), restaurant dining (38% to 9%), indoor fitness (31.9% to 8.4%), and transit use (11% to 1.3%). There was an increase in regular use of outdoor fitness (31.9% to 67.1%, p<0.003).

Persons with IBD who tested positive for COVID-19 were more likely to regularly dine in a restaurant (16.8% vs. 4.7% for COVID negative, p<0.001), engage in indoor fitness activities (14% vs. 5.1%, p<0.001), and travel outside Calgary (21% vs. 11.2%, p=0.004) post-lockdown.

Post-lockdown, a greater proportion of EW were COVID positive (50.4%) compared to non-EW (38.6%) (p=0.04).

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Conclusion(s)

Over a two-year period, two-thirds of our cohort did not test positive for COVID-19. Those with IBD who avoided COVID tended to be older, male, have 4 doses of vaccine, and reduce their risk of exposure through social and occupational modifications, perhaps in response to public health guidance.

Disclosure of Interest

None Declared

A15 GENETIC OR DIET-ASSOCIATED DEFECTS IN MUCUS FACILITATE ULCERATIVE COLITIS PATHOBIONT-DRIVEN COLITIS

Background

The Inflammatory Bowel Diseases (IBD), Crohn’s Disease (CD) and ulcerative colitis (UC) affect > 270,000 Canadians and are increasing in incidence. Ileal CD has been linked to the overgrowth of mucosal adherent E. coli. Recent studies have also implicated the adherence of Escherichia coli pathobionts to the colonic mucosa of UC patients. Using the representative UC E. coli pathobiont p19A, we recently demonstrated it aggravated chemical-induced colitis in susceptible mice, through the actions of the toxin alpha-hemolysin, and by adhering to the inflamed colonic mucosa via the adhesin FimH. It is less clear what host factors control susceptibility to the UC pathobionts. One of the potential candidates is the glycosylated mucin (Muc2) which forms the mucus layer that covers the colonic epithelium and is often impaired in UC patients.

Purpose

To define the role of mucus structure and function in determining susceptibility to the p19A pathobiont, and its ability to cause colitis in mice.

Method

In vitro growth was assessed to test p19A’s ability to utilize mucin-derived sugars as nutrients. Susceptibility to p19A was tested in two mouse models of colonic mucus impairment. The first is a mouse strain deficient in core 1 derived O-glycans in their intestinal epithelial cells (IEC C1galt1^-/-), resulting in reduced Muc2 glycosylation, and thus a thin and impaired mucus barrier. The second model involves feeding wildtype (WT) C57BL/6CR mice a fiber-free (FF) diet, resulting in a significantly thinner colonic mucus layer. The mice were subsequently orally gavaged with p19A and their susceptibility determined by p19A burdens, intestinal histopathology, inflammatory cytokine and short chain fatty acid (SCFA) production.

Result(s)

When tested in vitro, the p19A pathobiont was found to use an array of mucin-derived sugars as sole carbon source to proliferate. Following oral gavage of WT mice fed a normal diet, immunostaining identified p19A within the colonic mucus but it did not reach the colonic mucosa or cause disease. In contrast, p19A was found at the colonic mucosal surface of mucus-defective IEC C1galt1^-/- mice (as compared to IEC C1galt1^flox/flox mice) and in WT mice fed a fiber-free diet. This mucosal adherence was associated with increased body weight loss during the course of infection, as well as increased p19A burdens, colonic pathology and pro-inflammatory cytokine expression. Especially fiber-free diet-fed mice showed reduced SCFA levels in their feces at baseline. When the mice were given exogenous SCFA (tributyrin) orally, p19A infection was reduced.

Conclusion(s)

Our results indicate that UC E. coli pathobionts are able to dwell within colonic mucus and utilize mucin sugars as nutrients. Moreover, they can reach the mucosal surface and induce colitis in hosts suffering genetic or diet-based mucus dysfunction. In part, this susceptibility reflects the important role played by mucus in the production of SCFA, suggesting potential therapeutic approaches for patients suffering UC.

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CCC, CIHR

Disclosure of Interest

None Declared

A142 APPROPRIATENESS OF POST-ENDOSCOPY CARE IN PATIENTS PRESENTING WITH FOOD BOLUS IMPACTIONS OVERNIGHT: A POPULATION-BASED MULTICENTER COHORT STUDY

Background

Appropriate management of esophageal food bolus impactions includes endoscopic evaluation and follow-up for potential underlying esophageal pathology. Patients who present with impactions at night may not receive optimal long-term post-endoscopy care due to patient-, physician-, or system-related factors.

Purpose

We aimed to evaluate the appropriateness of care for patients who present with food bolus impactions after regular daytime hours.

Method

We conducted a retrospective, population-based, multi-center cohort study of adult patients undergoing endoscopy for food impaction between 19:00-06:59 from 2016-2018 in the Calgary Health Zone, Canada. Appropriate post-endoscopy care was defined by a composite of a follow-up clinic visit, repeat endoscopy, other appropriate investigations (e.g., manometry), or appropriate medical treatment (e.g., proton pump inhibitor). Predictors of inappropriate care were assessed using multivariable logistic regression, expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Result(s)

A total of 323 patients underwent an after-hours or overnight endoscopy for food bolus impaction. 25.4% (82/323) of patients did not receive appropriate post-endoscopy care. Predictors of inappropriate care included rural residence (aOR 2.66 [95% CI: 1.18-6.01], p=0.02), first food bolus presentation (aOR 2.38 [95% CI: 1.04-5.44], p=0.04), and absence of a specific pathology during the index procedure (aOR 3.01 [95% CI: 0.97-9.29], p=0.05), suggesting a potential association with clinician cognitive bias. Among patients who were followed, 18.9% (35/185) had a change in the original diagnosis.

Image

Conclusion(s)

One quarter of patients presenting with a food bolus impaction at night do not receive appropriate post-endoscopy care. System-based interventions should target this high-risk population as the diagnosis and management may change with follow-up.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

A195 DURABILITY OF SEROLOGICAL RESPONSES AFTER SECOND, THIRD AND FOURTH DOSE OF SARS-COV-2 VACCINATION IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Adequate serological responses following two-dose regimens and additional doses of SARS-CoV-2 vaccination have been demonstrated for the vast majority of those with IBD. However, antibody levels following 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination may decrease over time in the IBD population.

Purpose

We assessed the durability of serological responses to 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination over time in a cohort of IBD patients.

Method

Adults with IBD who received at least one dose of a SARS-CoV-2 vaccine (n=559) were evaluated for serological response to the spike protein of SARS-CoV-2 using the Abbott IgG II Quant assay with a seroconversion threshold of ≥ 50 AU/mL. The geometric mean titer (GMT) with 95% confidence intervals (CI) were calculated and stratified by weeks (1–8, 8–16, 16–24, 24+ weeks) after each vaccine dose. We compared stratified GMTs with Mann–Whitney U tests using a significance level of 0.05.

Result(s)

Our cohort (n=559) comprised the following patient characteristics: 82.8% were 18–65 years-old (n = 463), 53.1% were female (n =297), and 71.6% had Crohn’s disease (n =400). IBD medications were classified in the following mutually exclusive groups: No immunosuppressives 10.5% (n = 59), anti-TNF monotherapy 35.8% (n = 200), immunomodulatory monotherapy 2.1% (n =12 ), vedolizumab 11.8% (n =66 ), ustekinumab 20.4% (n =114 ), tofacitinib 1.2% (n =7 ), combination therapy 15.9% (n = 89), and prednisone 2.1% (n =12). For vaccine type, 85.6% and 82.3% had Pfizer for 3^rd and 4^th dose, respectively, while the remainder had Moderna. Seroconversion rates 1–8 weeks after 3^rd and 4^th dose were both 99.9%.

Figure 1 compares GMTs with 95% CI by weeks after each vaccine dose. GMTs are highest 1–8 weeks after 2^nd dose (4053 AU/mL; 95% CI: 3468, 4737 AU/mL; n=337), 3^rd dose (12116 AU/mL; 10413, 14098 AU/mL; n=256), and 4^th dose (14337 AU/mL; 10429, 19710 AU/mL; n=67). Subsequently, antibody levels decay from 1–8 weeks to 8–16 weeks (p<0.001) for 2^nd dose (mean difference: –2224 AU/mL), 3^rd dose (mean difference: –7526 AU/mL), and 4^th dose (mean difference: –9715 AU/mL). Compared to 16–24 weeks after 2^nd dose, antibody levels 24+ weeks after were similar (GMTs: 795 AU/mL vs. 1043 AU/mL, p=0.52). For third dose, antibody levels 8–16 weeks and 16–24 weeks after vaccination were similar (4590 AU/mL vs. 4073 AU/mL, p=0.73) along with 16–24 weeks compared to 24+ weeks after vaccination (4073 AU/mL vs. 5876 AU/mL, p=0.18).

Image

Conclusion(s)

Within 1–8 weeks after each dose of vaccine, serological responses spikes with each subsequent dose yielding a higher GMT. While antibody levels decay 8–16 weeks after each dose, similar GMT levels beyond 16 weeks may indicate durability of antibody levels over a longer duration of time.

Disclosure of Interest

None Declared

Clinical comparison of superior thyroid artery perforator flap and sternocleidomastoid myocutaneous flap for intraoral reconstruction

The aim was to evaluate the techniques and outcomes of superior thyroid artery perforator flaps (STAPF) for intraoral reconstruction and to compare them with those of the sternocleidomastoid myocutaneous flap (SCMMF). The cases of 43 patients who underwent reconstruction with either a SCMMF or STAPF for the repair of a medium-sized intraoral defect, between January 2013 and December 2020, were reviewed retrospectively. Although both flaps are based on the superior thyroid artery, their specific harvesting techniques largely differ. All SCMMF (n = 23) were superiorly-based rotational flaps with myocutaneous designs. The STAPF cases (n = 20) included 18 septocutaneous flaps and two chimeric flaps. The flap size was larger in the STAPF group (P = 0.008), while incomplete level IIB dissection (oncological safety) was more frequent in the SCMMF group (P = 0.002). The flap necrosis rate was lower in the STAPF group (STAPF 15% vs SCMMF 34.8%, though this was not statistically significant). Cox multivariate analysis showed that the postoperative flap outcome (total flap necrosis vs flap survival; hazard ratio 27, 95% confidence interval 2.149-336.05; P = 0.001) and complications (excluding fistula) (hazard ratio 14, 95% confidence interval 1.314-142.767; P = 0.029) were associated with overall patient survival. Both speech (P < 0.001) and neck mobility (P < 0.001) functions were superior with STAPF reconstruction. Compared with the traditional SCMMF, the STAPF was found to have a lower necrosis rate with uncompromised oncological safety during harvesting. The STAPF is a good alternative for the repair of medium-sized head and neck defects.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Pharmacological targeting of MTHFD2 suppresses NSCLC via the regulation of ILK signaling pathway

Lung cancer is the most common cause of cancer related deaths worldwide with the highest mortality rate. Non-small cell lung cancer (NSCLC) accounts for about 85 % of lung cancers. Mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a bifunctional enzyme and is the most differentially expressed metabolic enzyme in various tumors including lung cancer. However, little is known about how MTHFD2 functions in NSCLC. Integrin-linked kinase (ILK) signaling plays key a role in tumor progression including metastasis, proliferation and migration. Here, we show that MTHFD2 inhibition results in suppression of cell growth, migration, invasion and epithelial-mesenchymal transition (EMT) in NSCLC. Microarray analysis suggests that MTHFD2 is positively associated with ILK signaling based on western blotting results. In addition, the phosphorylation of AMPKα plays an essential role in MTHFD2 regulation of ILK signaling. Further, the small-molecule compound C18 inhibits MTHFD2 with great efficiency. C18 blocks MTHFD2/ILK signaling pathway and restrains cell growth, migration, invasion, and EMT of NSCLC and induces apoptosis. In brief, our study found that the positive impact of MTHFD2 is mediated via ILK signaling pathway in NSCLC. Thus, blocking MTHFD2 represents a promising therapeutic strategy against NSCLC clinically.

[Directed differentiation of human induced pluripotent stem cells into midbrain]

OBJECTIVE

To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro.

METHODS

hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment.

RESULTS

hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH⁺, FOXA2⁺ and Tuj1⁺ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection.

CONCLUSION

HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.

Water-Air Interface Imaging: Recovering the Images Distorted by Surface Waves via an Efficient Registration Algorithm

Imaging through the wavy water-air interface is challenging since the random fluctuations of water will cause complex geometric distortion and motion blur in the images, seriously affecting the effective identification of the monitored object. Considering the problems of image recovery accuracy and computational efficiency, an efficient reconstruction scheme that combines lucky-patch search and image registration technologies was proposed in this paper. Firstly, a high-quality reference frame is rebuilt using a lucky-patch search strategy. Then an iterative registration algorithm is employed to remove severe geometric distortions by registering warped frames to the reference frame. During the registration process, we integrate JADE and LBFGS algorithms as an optimization strategy to expedite the control parameter optimization process. Finally, the registered frames are refined using PCA and the lucky-patch search algorithm to remove residual distortions and random noise. Experimental results demonstrate that the proposed method significantly outperforms the state-of-the-art methods in terms of sharpness and contrast.

Concrete Multi-Type Defect Classification Algorithm Based on MSSMA-SVM

In order to realize the automatic classification of internal defects for non-contact nondestructive testing of concrete, a concrete multi-type defect classification algorithm based on the mixed strategy slime mold algorithm support vector machine (MSSMA-SVM) was proposed. The concrete surface's vibration signal was obtained using a laser Doppler vibrometer (LDV) for four classification targets for no defect, segregation, cavity, and foreign matter concrete classification targets. The wavelet packet transform (WPT) decomposes the detected signals to get information on different frequency bands. The energy ratio change rate, energy ratio, and wavelet packet singular entropy of each node after the WPT were used as the feature input of MSSMA-SVM. The experimental results show that the designed MSSMA-SVM classifier can accurately detect the type, which provides a practical algorithm for classifying concrete defects by laser vibration measurement.

[Consolidate the foundation, steadily promote and comprehensively improve the quality control in prevention and management of venous thromboembolism in China]

Hospital-associated venous thromboembolism (HA-VTE) has become a public health problem that seriously affects the quality of medical care and patient safety. Many countries regarded VTE prevention as a key element of medical quality management, carried out quality improvement work in VTE prevention and achieved remarkable results. In China, there is also unremitting efforts and explorations in the field of VTE prevention and management. The national program for prevention and management of pulmonary embolism and deep vein thrombosis was officially launched. Through a series of measures such as excellent center construction, regional alliance, and strengthening of quality control and informatization, the national program has greatly promoted the construction of VTE prevention and management system in hospitals across the country. Strengthening the prevention and treatment of VTE has become the common will of the government, hospital administrators, clinical medical staff and the public. In the future, we need to continue to steadily promote the prevention and management of VTE, and comprehensively improve the quality control management level of VTE prevention and management in hospitals.

[Quality of life and risk factors in patients with herpes zoster]

Objective: To evaluate the quality of life and influencing factors of patients with herpes zoster (HZ) seen in hospitals. Methods: Based on Zoster Brief Pain Inventory (ZBPI) and Five-level EuroQol Five-dimensional Questionnaire (EQ-5D-5L), a cross-sectional survey was conducted to evaluate the pain severity and quality of life of 332 HZ cases seen in 22 hospitals of Lu'an City (Anhui Province), Zibo City (Shandong Province) and Tongchuan City (Shaanxi Province) from October to December 2021. The censored least absolute deviations (CLAD) model was used to analyze the related factors affecting the changes of patients' health utility values. Results: The 45.5% of 332 HZ cases were male. The median (Q₁,Q₃) age was 59 (50, 68) years. 59.64% of them assessed by ZBPI had moderate to severe pain in the past 24 hours (worst pain score≥5), and that of PHN cases was 84.8%(39/46). 77.7% (258/332), 77.4% (257/332) and 74.1% (246/332) of all patients reported that pain interfered with sleep, mood and general activities, respectively. Aging [β_40-49y (95%CI)=-0.11 (-0.15, -0.08); β_50-59y (95%CI)=-0.03 (-0.05, 0.00); β_60-69y (95%CI)=-0.09 (-0.12, -0.06); β_70-90y(95%CI)=-0.16 (-0.19, -0.12)], working status (unemployed) [β_farmer (95%CI)=0.15 (0.13, 0.18); β_retirees(95%CI)=0.21 (0.18, 0.24); β_employee (95%CI)=0.13 (0.10, 0.16) ], complications[β_PHN (95%CI)=-0.08 (-0.13, -0.04); β_{other complications} (95%CI)=-0.12 (-0.15, -0.08)], within 30 days after onset [β(95%CI)=-0.01 (-0.03, 0.01)] and treatment [β_{other complications} (95%CI)=-0.09 (-0.11, -0.06)] were related factors for the decline of health utility value (all P values <0.05). Conclusions: More than half of the patients with HZ had moderate to severe pain in the past 24 hours, which had a serious negative impact on the physical and mental health of the patients. Elderly patients, acute patients and patients with complications had lower health utility values and worse health status. We suggest that eligible people be vaccinated with HZ vaccine as soon as possible.

[Research progress of mesenchymal stem cell in the treatment of diabetic bladder dysfunction]

Diabetic bladder dysfunction (DBD) is a common complication in the lower urinary tract of diabetes. In recent years, mesenchymal stem cell (MSC) have broad application prospects in the treatment of DBD. MSC can migrate to damaged bladder tissue and differentiate into various cell types, such as urothelial cells, myofibroblasts, smooth muscle cells and nerve cells, promote bladder tissue repair and regeneration through paracrine effects. In addition, MSC also intervene in the pathological process of DBD, reverse disease progression, and restore partial bladder function through immune regulation, improvement of oxidative stress, and regulation of blood glucose. At present, the treatment of DBD with MSC is limited to preclinical animal experiments, clinical research and application should be pursued further.

Quantitative Intracerebral Iodine Extravasation in Risk Stratification for Intracranial Hemorrhage in Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Intracerebral hemorrhage poses a severe threat to the outcomes in patients with postthrombectomy acute stroke. We aimed to compare the absolute intracerebral iodine concentration and normalized iodine concentration ratio in predicting intracerebral hemorrhage in patients postthrombectomy.

MATERIALS AND METHODS

Patients with acute anterior circulation large-vessel occlusion who underwent mechanical thrombectomy and had successful recanalization were retrospectively included in the study. Dual-energy CT was performed within 1 hour after mechanical thrombectomy. Postprocessing was performed to measure the absolute intracerebral iodine concentration and the normalized iodine concentration ratio. The correlation between the absolute intracerebral iodine concentration and the normalized iodine concentration ratio was analyzed using the Spearman rank correlation coefficient. We compared the area under the receiver operating characteristic curve of the absolute intracerebral iodine concentration and the normalized iodine concentration ratio using the DeLong test.

RESULTS

We included 138 patients with successful recanalization. Of 43 patients who did not have parenchymal contrast staining on postthrombectomy dual-energy CT, 5 (11.6%) developed intracerebral hemorrhage. Among patients (95/138, 68.8%) with parenchymal contrast staining, 37 (38.9%, 37/95) developed intracerebral hemorrhage. The absolute intracerebral iodine concentration was significantly correlated with the normalized iodine concentration ratio (ρ = 0.807; 95% CI, 0.718-0.867; P < .001). The cutoffs of the normalized iodine concentration ratio and absolute intracerebral iodine concentration for identifying patients with intracerebral hemorrhage development were 222.8%, with a sensitivity of 67.6% and specificity of 76.4%, and 2.7 mg I/mL, with a sensitivity of 75.7% and specificity of 65.5%, respectively. No significant difference was found between the areas under the receiver operating characteristic curve for the absolute intracerebral iodine concentration and the normalized iodine concentration ratio (0.753 versus 0.738) (P = .694).

CONCLUSIONS

The hemorrhagic transformation predictive power of the normalized iodine concentration ratio is similar to that of the absolute intracerebral iodine concentration in patients with successful recanalization.