A Pre-Leukemic DNA Methylation Signature in Healthy Individuals at Higher Risk for Developing Myeloid Malignancy

PURPOSE

DNA methylation alterations are widespread in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), some of which appear to have evolved independently of somatic mutations in epigenetic regulators. While the presence of somatic mutations in peripheral blood can predict the risk of development of AML and MDS, its accuracy remains unsatisfactory.

EXPERIMENTAL DESIGN

We performed global DNA methylation profiling in a case-control study nested within Singapore Chinese Health Study to evaluate if DNA methylation alterations were associated with AML/MDS development. Targeted deep sequencing and methylated DNA immunoprecipitation sequencing (MeDIP-seq) were performed on peripheral blood collected a median of 9.9 years prior to diagnosis of AML or MDS, together with age-matched still healthy individuals as controls.

RESULTS

Sixty-six individuals who developed AML or MDS displayed significant DNA methylation changes in the peripheral blood compared with 167 age- and gender-matched controls who did not develop AML/MDS during the follow up period. Alterations in methylation in the differentially methylation regions (DMRs) were associated with increased odds of developing AML/MDS.

CONCLUSIONS

The epigenetic changes may be acquired independently and prior to somatic mutations that relevant for AML/MDS development. The association between methylation changes and the risk of pre-AML/MDS in these individuals was considerably stronger than somatic mutations, suggesting that methylation changes could be used as biomarkers for pre- AML/MDS screening.

[Research on cone-beam CT of mandibular foramen location in children aged 7-10 years]

Objective: Cone-beam CT (CBCT) images were used to investigate the relative position changes of mandibular foramen in the mandible of children and the relative position relationship with the occlusal plane, so as to provide clinical guidance for inferior alveolar nerve block (IANB) anesthesia of children. Methods: The CBCT data of 202 children aged 7-10 years in the image database of the First Affiliated Hospital of Zhengzhou University from March 2021 to February 2023 were included. Patients were divided into 4 groups according to age diffrences as 7-year-old, 8-year-old, 9-year-old and 10-year-old. There were 20 males and 22 females in the 7-year-old group, 31 males and 28 females in the 8-year-old group, 30 males and 26 females in the 9-year-old group, and 22 males and 23 females in the 10-year-old group, respectively. Forty-six adults aged 25-30 years were selected as control group, 24 males and 22 females included. The distance between the center point of mandibular foramen with the anterior edge of ascending ramus of mandible (MF-A), the posterior edge of the ascending ramus of mandible (MF-P) and the shortest distance between the center point of mandibular foramen with occlusal plane (MF-OP) were measured. The angle between the center point of the mandibular foramen with the sagittal plane of the mandibular first deciduous molar (or mandibular first premolar) and mandibular second deciduous molar (or mandibular second premolar) (∠A) was measured. The data of mandibular foramen were compared between the left and right sides and among different genders and different age groups. Results: The position of mandibular foramen in children aged 7-10 years maintained bilateral symmetry, and mandibular growth and development were relatively consistent between different genders (P>0.05). MF-A increased with age, from (15.83±1.28) mm in 7-year-old group to (17.10±1.60) mm in 10-year-old group gradually. There were significant differences in MF-A between the 10-year-old group with the 7-year-old group, the 8-year-old group [(15.98±1.53) mm] and the 9-year-old group [(16.43±1.49) mm] respectively (P<0.05). MF-P increased with age, from (9.12±1.17) mm in 7-year-old group to (11.25±1.60) mm in 10-year-old group. There were statistically significant differences in MF-P among all age groups (P<0.05). MF-OP increased with age, from below the plane (-0.24±2.31) mm in the 7-year-old group to above the plane (1.08±1.95) mm in the 10-year-old group. There were significant differences between the 10-year-old group with the 7-year-old group, the 8-year-old group [(-0.01±1.93) mm], and the 9-year-old group [(0.31±1.95) mm] (P<0.05). The ratio of MF-A to MF-P decreased as the age increased, from 1.77±0.30 in the 7-year-old group to 1.55±0.29 in the 10-year-old group. There were statistically significant differences in MF-A/MF-P among all age groups (P<0.05), except for between the 8-year-old group (1.66±0.19) and the 9-year-old group (1.65±0.28) (P>0.05). The ∠A of children in all age groups was significantly greater than the reference value (45°) (P<0.05), and there was no statistical significance among all groups (P>0.05). The differences of MF-A, MF-P, MF-OP, MF-A/MF-P and ∠A between children of all age groups and the control group were statistically significant (P<0.05). Conclusions: In children aged 7-10 years, the mandibular foramen is located behind the midpoint of the anteroposterior diameter of the mandibular ramus. With the increase of age, the mandibular foramen gradually moves from below the occlusal plane to above, and is flush with the occlusal plane at the age of 8 years. Compared with adults, the mandibular foramen in children is more backward and lower on the medial side of the mandibular ramus. When IANB is operated to children, the syringe can be moved distally from the contact area of the contralateral deciduous molars or premolars, so that the injection angle can be greater than the reference value 45° to improve the accuracy of IANB.

Somatic mutational landscape of hereditary hematopoietic malignancies caused by germline variants in RUNX1, GATA2, and DDX41

Individuals with germ line variants associated with hereditary hematopoietic malignancies (HHMs) have a highly variable risk for leukemogenesis. Gaps in our understanding of premalignant states in HHMs have hampered efforts to design effective clinical surveillance programs, provide personalized preemptive treatments, and inform appropriate counseling for patients. We used the largest known comparative international cohort of germline RUNX1, GATA2, or DDX41 variant carriers without and with hematopoietic malignancies (HMs) to identify patterns of genetic drivers that are unique to each HHM syndrome before and after leukemogenesis. These patterns included striking heterogeneity in rates of early-onset clonal hematopoiesis (CH), with a high prevalence of CH in RUNX1 and GATA2 variant carriers who did not have malignancies (carriers-without HM). We observed a paucity of CH in DDX41 carriers-without HM. In RUNX1 carriers-without HM with CH, we detected variants in TET2, PHF6, and, most frequently, BCOR. These genes were recurrently mutated in RUNX1-driven malignancies, suggesting CH is a direct precursor to malignancy in RUNX1-driven HHMs. Leukemogenesis in RUNX1 and DDX41 carriers was often driven by second hits in RUNX1 and DDX41, respectively. This study may inform the development of HHM-specific clinical trials and gene-specific approaches to clinical monitoring. For example, trials investigating the potential benefits of monitoring DDX41 carriers-without HM for low-frequency second hits in DDX41 may now be beneficial. Similarly, trials monitoring carriers-without HM with RUNX1 germ line variants for the acquisition of somatic variants in BCOR, PHF6, and TET2 and second hits in RUNX1 are warranted.

Identification of diagnostic biomarkers and immuno-infiltration analysis for rheumatoid arthritis based on biological information and WGCNA

OBJECTIVE

Rheumatoid arthritis (RA), as an autoimmune disease, poses a huge social and economic burden worldwide. Although the diagnosis of RA has been gradually improved, there is still a need to discover accurate and rapid biomarkers for diagnosis and therapy with a precise understanding of the disease. This study aimed to screen diagnostic biomarkers and analyze immune infiltration in RA based on weighted gene co-expression network analysis (WGCNA).

MATERIALS AND METHODS

Firstly, we screened the experimental and validation sets associated with RA from the GEO database. Crossover genes were obtained using differential genes (DEGs) and key modules in WGCNA. Subsequently, the crossover genes were constructed into protein-protein interaction (PPI) networks and screened to obtain hub genes. The receiver operating characteristic (ROC) curve assessment was performed to identify diagnostic biomarkers. In addition, we used the Cibersort algorithm for immuno-infiltration analysis and the DGidb database to search for drugs associated with diagnostic biomarkers.

RESULTS

In the end, 377 DEGs were identified, and the enrichment analysis revealed significant associations with the immune system. Blue modules in the WGCNA analysis were positively associated with the disease and were identified as key modules. ROC curves evaluated the four hub genes, which significantly differentiated RA from healthy controls and could be used as diagnostic biomarkers. In further analysis, we found that RA is closely related to immunity, and the search identified multiple drugs that hold promise for treating RA.

CONCLUSIONS

BCL2A1, PTGS2, FAS, and LY96 may be used as diagnostic biomarkers, which is significant for diagnosing and treating RA.

[Analysis of the efficacy of endoscopic transnasal surgery for sinonasal and skull base adenoid cystic carcinoma]

Objective: To evaluate the efficacy of endoscopic transnasal surgery for sinonasal and skull base adenoid cystic carcinoma (ACC), and to analyze the prognostic factors. Methods: Data of 82 patients (43 females and 39 males, at a median age of 49 years old) with sinonasal and skull base ACC who were admitted to XuanWu Hospital, Capital Medical University between June 2007 and June 2021 were analyzed retrospectively. The patients were staged according to American Joint Committee on Cancer (AJCC) 8th edition. The disease overall survival(OS) and disease-free survival(DFS) rates were calculated by Kaplan-Meier analysis. Cox regression model was used for multivariate prognostic analysis. Results: There were 4 patients with stage Ⅱ, 14 patients with stage Ⅲ, and 64 patients with stage Ⅳ. The treatment strategies included purely endoscopic surgery (n=42), endoscopic surgery plus radiotherapy (n=32) and endoscopic surgery plus radiochemotherapy (n=8). Followed up for 8 to 177 months, the 5-year OS and DFS rates was 63.0% and 51.6%, respectively. The 10-year OS and DFS rates was 51.2% and 31.8%, respectively. The multivariate Cox regression analysis showed that late T stage and internal carotid artery (ICA) involvement were the independent prognostic factors for survival in sinonasal and skull base ACC (all P<0.05). The OS of patients who received surgery or surgery plus radiotherapy was significantly higher than that of patients who received surgery plus radiochemotherapy (all P<0.05). Conclusions: Endoscopic transonasal surgery or combing with radiotherapy is an effective procedure for the treatment of sinonasal and skull base ACC. Late T stage and ICA involvement indicate poor prognosis.

[Research progress in immunomodulation in orthodontic tooth movement]

In the process of orthodontic tooth movement, the secretion of cytokines by immune cells or cell-cell interaction affects the regulation of osteoclast and osteoblast differentiation. Increasingly, studies have focused on the role in the immune system in orthodontic bone remodeling. Based on the biological role of different immune cells or cytokines, this article briefly presents the research progress of immunomodulation in orthodontic tooth movement and future perspective, hopefully providing a deeper and more comprehensive understanding of the biological mechanism in orthodontic tooth movement.

Sub genomic analysis of SARS-CoV-2 using short read amplicon-based sequencing

The novel coronavirus disease 2019 (COVID-19) pandemic poses a serious public health risk. In this report, we present a modified sequencing workflow using short tiling (280bp) amplicons library preparation method paired with Illumina's iSeq100 desktop sequencer. We demonstrated the utility of our workflow in identifying gapped reads that capture characteristics of subgenomic RNA junctions within our patient cohort. These analytical and library preparation approaches allow a versatile, small footprint and decentralized deployment that can facilitate comprehensive genetics characterizations during outbreaks. Based on the sequencing data, Taqman assays were designed to accurately capture the quantity of subgenomic ORF5 and ORF7a RNA from patient samples and demonstrated utility in tracking subgenomic titres in patient samples when combined with a standard COVID-19 qRT-PCR assay.

Impact of sodium-glucose co-transporter 2 inhibitors on cardiovascular outcomes in patients with chronic kidney disease: Hong Kong-wide, observational, propensity score matched analysis

Purpose

The impact of SGLT2i on patients with advanced chronic kidney disease (CKD) is limited. We aimed to compare hospitalization for heart failure (HHF) and cardiovascular (CV) death between new users of SGLT2i versus non-users across the spectrum of CKD stages.

Methods

We retrospectively analyzed 22,657 patients with CKD who were prescribed SGLT2i between August 2015 and August 2020 in 16 public hospitals in Hong Kong. Propensity-matched cohorts of SGLT2i users and non-users (n=3,704 per group) were generated on the basis of age, gender, baseline eGFR, co-morbidities and medications. Time to HHF and CV death was analyzed using COX proportional hazards model. Subgroup analysis was performed to detect heterogeneity of effect across stages of CKD.

Results

Of the whole cohort (N=22,657), the percentage of SGLT2i users in CKD stage G1 to G5 were 82.1%, 49.0%, 19.8%, 10.3%, 4.3%, and 1.6%, respectively. SGLT2i users and non-users groups were well balanced at baseline (mean age 64.7±12.7, female 37.1%), with a median follow-up of 2.8 (IQR: 1.1–5.1) years (22876.5 person-years). Overall, SGLT2i was associated with reduced risk of HHF (Hazards Ratio (HR) 0.12 (95% CI (0.10–0.16) and CV death (HR 0.17 (95% CI (0.12–0.25), compared with non-users. Subgroup analysis demonstrated benefit of SGLT2i on CV death in G3 to G5 groups but not in patients in earlier CKD stages (P for interaction &lt;0.001) (Table). Reduction in risk of HHF was comparable across all CKD stages (P for interaction = 0.1).

Conclusion

Utilization of SGLT2i was associated with significant reduction in HHF and CV death in patients with moderate to severe CKD in a real-world setting. Our results suggest significant heterogeneity in CV death reduction with the largest benefit in patients with stage G3a and more advanced CKD.

Funding Acknowledgement

Type of funding sources: None.

Timing of initiation of sodium-glucose co-transporter 2 inhibitor in patients with diabetes and chronic cardiac failure

Purpose

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of first hospitalization for heart failure (HHF) in patients with type 2 diabetes. We aimed to evaluate the impact of early initiation of SGLT2 inhibitors on recurrent HHF in diabetic patients with chronic cardiac failure.

Methods

We retrospectively analyzed 1,363 consecutive diabetic patients with chronic cardiac failure with index HHF between August 2015 and August 2020 in 16 public hospitals in Hong Kong who were prescribed SGLT2i (empagliflozin=1,009, 74% and dapagliflozin =354, 26%).Patients who initiated SGLT2i at discharge of index HHF were compared to those who were not. Risk of recurrent HHF was compared, using adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression models, accounting for death as competing risk, adjusting for age, gender, concurrent medications. Comparisons were also conducted between initiation of SGLT2i ≤30 vs &gt;30 days; and ≤90 vs. &gt;90 days after discharge.

Results

Of 1,363 patients (mean age 63.9±11.6, female 34.6%), 85% had no history of previous HHF at enrollment, 11.9% had up to 2 and 3.1% and 3.1% ≥3 HHF in the past 5 years. SGLT2i was initiated in 37.4% of patients at discharge of index HHF and the median time from index HHF to SGLT2i initiation for the other patients was 4.2 (IQR: 0–20.4) months. During a median follow-up of 1.3 (IQR: 0.2–2.7) years, initiation of SGLT2i at discharge was associated with lower risk of recurrent HHF (aSHR = 0.79, 95% CI: 0.68–0.92). Similar effect was observed between SGLT2i initiation ≤30 vs. &gt;30 days (aSHR = 0.82, 95% CI: 0.70–0.95) but not between ≤90 vs. &gt;90 days (P=0.19).

Conclusion

Among patients with diabetes and chronic cardiac failure, the risk of recurrent HHF was reduced when SGLT2 was initiated early after index HHF.

Funding Acknowledgement

Type of funding sources: None.

Low-density lipoprotein cholesterol target attainment among statin-naive Chinese atherosclerotic vascular disease patients

Background

Low-density lipoprotein cholesterol (LDL-C) of patients with atherosclerotic vascular disease (ASCVD) is expected to be lowered by ≥50% and &lt;1.4 mmol/L. Despite the use of lipid-lowering therapies, most of Chinese patients failed to meet the treatment target.

Purpose

We aimed to evaluate the potential of different statin intensities on LDL-C target attainment among statin-naïve Chinese ASCVD patients.

Methods

We retrospectively analyzed statin-naïve ASCVD patients who were initiated with statin therapy between January and July 2020 from 43 public hospitals or clinics in Hong Kong. Patients were divided into high-intensity (HI-S, atorvastatin 40–80 mg, rosuvastatin 20–40 mg), moderate-intensity (MI-S, atorvastatin 10–20 mg, rosuvastatin 5–10 mg, simvastatin 20–40 mg) and low-intensity (LI-S, simvastatin 10 mg) statin groups. With baseline and follow-up LDL-C, percentage reduction was calculated and the distance to LDL-C target was investigated within groups.

Results

Of 7,241 patients (mean age 61.8±12.4 years and 64.2% male), 4,451 (61.5%) had coronary artery disease, 109 (1.5%) peripheral artery disease, and 2,879 (39.8%) cerebrovascular disease. HI-S, MI-S and LI-S were prescribed in 20% (n=1,450), 61.1% (n=4,421) and 18.9% (n=1,370) patients, respectively. Mean baseline LDL-C was 2.9±1.0 mmol/L and mean follow-up value was 1.9±0.8 mmol/L with median LDL-C reduction of 46.1%, 40.4%, and 32.0% by HI-S, MI-S, and LI-S, respectively. 42.1%, 31.8%, and 14.7% of patients on HI-S, MI-S, and LI-S achieved ≥50% LDL-C reduction and only 23.5%, 18.2%, and 8.8% reached both ≥50% LDL-C reduction and &lt;1.4 mmol/L. One in ten patients require further ≥50% LDL-C reduction to reach &lt;1.4 mmol/L.

Conclusion

In statin-naïve Chinese ASCVD patients, most patients did not reach guidelines recommended LDL-C target even with high-intensity statin. Early statin up-titration or addition of non-statin lipid-lowering therapy may be required in majority of patients.

Funding Acknowledgement

Type of funding sources: None.

Variant landscape of the RYR1 gene based on whole genome sequencing of the Singaporean population

The RYR1 gene codes for a ryanodine receptor which is a calcium release channel in the skeletal muscle sarcoplasmic reticulum. It is associated with Malignant Hyperthermia (MH) and congenital myopathies including Central Core Disease (CCD), Multiminicore Disease (MMD) and Congenital Fibre-Type Disproportion (CFTD). There is currently little information on the epidemiology of RYR1 variants in Asians. Our study aims to describe the RYR1 variant landscape in a Singapore cohort unselected for RYR1-associated conditions. Data was retrieved from the SG10K pilot project, where whole genome sequencing was performed on volunteers unselected and undetermined for RYR1-associated conditions. Variants were classified based on pathogenicity using databases ClinVar and InterVar. Allele frequencies of pathogenic variants were compared between Chinese, Indians and Malays. Using databases ExAC, GnomAD and GenomeAsia 100k study, we further compared local allele frequencies to those in Europe, America and Asia. Data was analysed using R Commander. Significant P value was set at p < 0.05. Majority of the RYR1 variants were missense mutations. We identified four pathogenic and four likely pathogenic RYR1 variants. All were related to the aforementioned RYR1-associated conditions. There were 6 carriers of RYR1 pathogenic variants amongst 4810 individuals, corresponding to an allele frequency of 0.06%. The prevalence of pathogenic variants was the highest amongst Indians (4 in 1127 individuals) (p = 0.030). Majority of pathogenic and likely pathogenic mutations were missense and located in mutational hotspots. These variants also occurred at higher frequencies in Asians than globally. This study describes the variant landscape of the RYR1 gene in Singapore. This knowledge will facilitate genetic screening for RYR1-related conditions.

A Single Amino Acid Substitution in Structural Protein VP2 Abrogates the Neurotropism of Enterovirus A-71 in Mice

Enterovirus 71 (EV-A71) causes hand, foot, and mouth disease (HFMD) in children and has been associated with neurological complications. With no specific treatment and a monovalent vaccine limited to the Chinese market, HFMD remains a serious public health concern and an economic burden to affected societies. The molecular mechanisms underpinning EV-A71 neurovirulence have yet to be fully elucidated. In this work, we provide experimental evidence that a single amino acid substitution (I to K) at position 149 in structural protein VP2 of a non-mouse-adapted EV-A71 strain completely and specifically abrogated its infectivity in murine motor neuron-like NSC-34 cells. We showed that VP2 I149K mutant was impaired in murine SCARB2-mediated entry step but retained the ability to attach at the cell surface. In vivo, VP2 I149K mutant was fully attenuated in a symptomatic mouse model of progressive limb paralysis. While viral titers in limb muscles were comparable to mice infected with parental wild-type strain, significantly lower viral titers were measured in the spinal cord and brain, with minimal tissue damage, therefore indicating that VP2 I149K mutant is specifically impaired in its ability to invade the central nervous system (CNS). This study highlights the key role of amino acid at position 149 in VP2 in EV-A71 neurovirulence, and lends further support that the EF loop of VP2 represents a potential therapeutic target.

A71 POLYP TO ADENOMA CONVERSION FACTOR AS A SURROGATE FOR ADENOMA DETECTION RATE-– FINDINGS FROM THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Background

The adenoma detection rate (ADR) is one of the main quality indicators of a colonoscopy but requires combining endoscopic and histologic data. However, the polyp detection rate (PDR) requires only endoscopic assessment and has been proposed as a proxy measure for the ADR.

Aims

To calculate a conversion factor for PDR to ADR, for use as a future surrogate of ADR when only PDR is available.

Methods

The Southwest Ontario Colonoscopy cohort consists of all outpatient colonoscopies performed across 20 hospitals in Southwestern Ontario between April 2017 and February 2018. Data was collected prospectively through a mandatory quality assurance form that was completed after each procedure and pathology reports were manually reviewed. Endoscopies with associated histologic findings were included.

The PDR and true ADR were calculated for each physician. A weighted polyp to adenoma detection rate quotient (APDRQ) was calculated, weighting each physician’s APDRQ by the number of procedures performed. The APDRQ was determined for all outpatient procedures and specifically for screening/surveillance indications.

Results

During the study period, 57 endoscopists performed 31,721 colonoscopies. The overall PDR was 41.1% and the ADR was 26.5%. The weighted ADPDRQ was 0.638 (95% CI: 0.600, 0.675). When limited to screening/surveillance colonoscopies, the weighted ADPDR was 0.616 (95% CI: 0.564, 0.669). To better understand the influence of endoscopists with low ADR: PDR, we excluded those with ratio below (<2 standard errors) the average, which resulted in greater ADR: PDR for all colonoscopies 0.695 (95% CI: 0.679, 0.711) and for screening/surveillance colonoscopies and 0.692 (95% CI: 0.677, 0.707).

Conclusions

In this large, population-based, cohort study, we calculated the ADR; PDR ratio. We propose this may be used in future studies to infer ADR when only PDR is available.

Scatter plot of correlation between ADR and PDR, by physician. The dashed line indicates the line for which ADR=PDR, the maximum value the ADR can take for a given PDR. The marker size is proportional to the number of colonoscopies performed.

Funding Agencies

None

A106 THE EPIDEMIOLOGY OF COMPLEX COLONIC POLYPS: A POPULATION BASED STUDY OF THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Background

Complex polyps are well recognized amongst endoscopists, but its definition varies in the literature and from one endoscopist to another. Despite its clinical importance, the epidemiology of complex polyps is poorly understood.

Aims

To assess the epidemiology of complex polyps on a population level, and in FIT positive individuals.

Methods

The Southwest Ontario Colonoscopy cohort is a prospective database consisting of all adult patients undergoing colonoscopy at 21 hospitals in Southwest Ontario. Data is collected through a mandatory quality assurance form completed by the endoscopist after each procedure. All outpatient adult colonoscopies for any indication were included. Incomplete colonoscopies, repeat procedures, and poor preparation colonoscopies were excluded. A manual review of the colonoscopy report was completed in cases where the description of the complex polyps was missing. The primary outcomes were the prevalence of complex polyps in the cohort, and in FIT positive patients. Secondary outcomes include endoscopic description of the complex polyp, rates of attempted and complete resection, and identification of possible associations between patient and endoscopist factors with complex polyp detection and removal. A multivariate logistic regression model was generated to assess for factors associated with complex polyp detection.

Results

From February 2019 to December 2020, 43389 colonoscopies were included, of which 1459 were for FIT positive patients. 2294 patients had a complex polyp, with a prevalence of 5.3% [95% CI 0.051–0.055], while the prevalence was 17.1% [95% CI 0.152–0.191] in the FIT positive cohort. Compared to average-risk patients undergoing colonoscopy for colon cancer screening, the odds ratio (OR) of detecting a complex polyp in individuals with positive FIT was 4.12 [95% CI 3.42–4.98, p<0.0001]. Among complex polyps,1324 (57.7%) were described as large (>2cm) and 1290 (56%) described as sessile. Of 2294 patients with complex polyps,1992 (86.8%) [95% CI 0.855–0.882] underwent a removal attempt, with successful complete removal as determined by the endoscopist achieved in 1905 patients (95.6%) [95% CI 0.947–0.965]. Compared to gastroenterologists, general surgeons and internists were less likely to detect a complex polyp, OR 0.67 [95% CI 0.61–0.73, p <0.0001] and 0.36 [95% CI 0.20–0.67, p=0.0011] respectively. Trainee involvement was associated with higher rate of complex polyp detection, OR 1.20 [95% CI 1.07–1.35, p=0.0022]. Females were less likely to have a complex polyp compared to males, OR 0.71 [95% CI 0.65–0.77, p<0.0001].

Conclusions

Complex polyps are more prevalent than previously reported in the literature, with a high prevalence among the FIT positive population compared to other indications of colonoscopy.

Funding Agencies

None

How to bridge residual distance to target low-density-lipoprotein cholesterol in acute coronary syndrome patients after initial statin therapy?

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Current guidelines recommend intensive low-density-lipoprotein cholesterol (LDL-C) lowering by ≥50% to target LDL-C &lt;1.4mmol/L after acute coronary syndrome (ACS). Residual distance to LDL-C target can help select treatment strategy after initial statin therapy.

PURPOSE

We aimed to evaluate residual distance to guideline recommended target LDL-C and the proportion of ACS patients who are projected to reach target LDL-C by different statin and non-statin lipid lowering strategies.

METHODS

We retrospectively analyzed 46,114 patients admitted with ACS who survived 1 year from 18 acute hospitals in Hong Kong between Jan 2014 and Dec 2018. Patients were divided into (i) high potency (HP-S; rosuvastatin ≥20mg, atorvastatin ≥40mg or simvastatin ≥80mg); (ii) non-high potency (NHP-S; other statin doses) statin users and (iii) no statin therapy. We calculated the mean distance and percentage LDL-C reduction required to reach dual LDL-C targets (&gt;50% reduction from baseline and &lt;1.4mmol/L). We assumed up-titration from NHP-S to HP-S would further reduce LDL-C by approximately 5-10%; addition of ezetimibe 15-20% and PCSK-9 inhibitor 50-60%.

RESULTS

Of 46,114 patients (60.7% males, mean age 76.2 ± 13.3 years), 80.4% (n = 10945/13614) had LDL-C ≥1.4mmol/L at 12-months after index ACS with 60.2% (n = 18319/30450), 31.9% (n = 9726/30450) and 8.0% (2405/30450) of patients on no statin, NHP-S and HP-S, respectively. 86% of HP-S and 93% of NHP-S users did not reach dual LDL-C targets at 12-months. Among patients on NHP-S and HP-S, the mean LDL-C at 12-months was 2.0 ± 0.7 and2.1 ± 0.9 mmol/L; mean residual distance to target 0.64 ± 0.7 and0.66 ± 0.9 mmol/L; and mean percentage LDL-C reduction required to reach dual LDL-C targets was 22.4 ± 33% and 18.8 ± 36%, respectively. 13% of statin users required &gt;50% further LDL-C reduction to reach targets. Projected proportion of NHP-S users to reach LDL-C targets is 11% (n = 430/3966) by up-titrating to HP-S, 21% (n = 828/3966) by up-titration to HP-S plus ezetimibe and 100% (n = 3966/3966) with PCSK-9 inhibitor plus HP-S and ezetimibe. Projected proportion of HP-S users to reach LDL-C targets is 13% (n = 143/1099) by ezetimibe and 100% (n = 1099/1099) with addition of PCSK-9 inhibitor. 

CONCLUSION

The use of high-potency statin was low and almost all statin users did not reach dual LDL-C targets at 12-months after index ACS. High potency statin plus ezetimibe is projected to bridge about a fifth of these patients to target LDL-C. PCSK-9 inhibitor is likely needed in the majority of patients who have not achieved target LDL-C at 12-months after ACS to reach guideline recommendations.

[Application of island flap and its combined flap on repairing nasal alae defects]

Objective: To evaluate the application of island flap and combined flap in one-stage reconstruction of nasal alae defects after external nasal tumor resection. Methods: Data of 11 patients with perforating or full-thickness defects of the alae after nasal tumor resection in XuanWu Hospital, Capital Medical University between June 2016 and February 2021 were analyzed retrospectively. There were 7 males and 4 females, and the ages ranged from 51 to 89 years. Island flap, island flap combined with nasolabial flap or V-Y advancement flap, and island flap combined with bilobed flap were applied according to the range of defects. Descriptive statistical method was applied to analyze the treatment effects. Results: All flaps of the 11 patients were successful survival and the incisions were primary healing. Being followed up for 5 to 59 months, the patients had satisfying appearance and ventilation function, and no tumor relapsed. Conclusion: For the patients with nasal alae defects after external nose tumor resection, selecting suitable island skin flap or combined skin flap can be used to reconstruct the ideal nasal appearance and function of the nose.

Validation of a multi-gene qPCR-based pharmacogenomics panel across major ethnic groups in Singapore and Indonesia

Aim: The clinical utility of pharmacogenomics (PGx) has been gaining traction alongside growing evidence that adverse drug reactions (ADRs) have significant genetic associations. Nala PGx Core^® is a multi-gene qPCR-based panel of 20 allele variants, comprising 18 SNPs and two CYP2D6 copy number markers across four pharmacogenes - CYP2C9, CYP2C19, CYP2D6 and SLCO1B1. Methods: In this study, we validated the performance of Nala PGx Core^® against benchmark methods, on the Singaporean and Indonesian populations. Results & conclusion: Nala PGx Core^® demonstrated robust and accurate genotyping when compared with other established benchmarks. Furthermore, the panel successfully characterized alleles of clinical relevance, such as CYP2D6*10 and CYP2D6*36, across major ethnic groups present of Singapore and Indonesia, suggesting its potential for adoption in clinical workflows regionally.

Does an empowerment-based self-care supportive intervention save cost for improving self-care and health service utilization among heart failure patients

Background

Heart failure (HF) evolves as a global pandemic and strains the over-stretched hospital service. Ineffective self-care remains the key factor to explain the avoidable hospital admission. Patient empowerment is as a theory-based strategy to optimize the patients' self-care changes for disease management [1]. Its cost-effectiveness to enhance self-care and health service utilization has yet to be determined.

Purpose

This was a double-blind randomized controlled trial to compare the effects and cost-effectiveness of a 12-week empowerment self-care program with a didactic education program on self-care maintenance and management as well as health service utilization among the community-dwelling HF patients.

Methods

A total of 236 HF patients were recruited from the specialist clinics of the Department of Cardiology in two regional hospitals. They were randomized to receive either the 12-week empowerment self-care program (Figure 1) or the 12-week didactic education. Outcome evaluation using the Self-care Heart Failure Index (SCHFI) at baseline, post-intervention (T1) and three months thereafter (T2), with record on the number of emergency room (ER) attendance and hospital admission. Cost effectiveness analyses were performed on total cost (medical, intervention and societal costs) incurred in both interventions as well as incremental cost-effectiveness ratios (ICER) expressed as incremental cost per 1) a reflected clinically meaningful improvement in self-care (i.e. a half standard deviation increase in SCHFI), 2) an ER attendance reduced, 3) a day of hospital stay reduced.

Results

As compared with the education group, the empowerment group reported significantly greater improvement in self-care management at T1 [B=13.77 (95% CI=6.07, 21.46), p&lt;0.001] and T2 [B=10.98 (95% CI=3.21, 18.75), p=0.006]. For cost-effective analysis, The ICER (empowerment-education) was −USD220/0.5 SD increase in SCHFI, indicating the mean cost saved per patient for making a clinically significant improvement in self-care was USD 220. The cost-effectiveness acceptability curve showed patients were willing to pay at USD 207- 441 for a 80–90% chance of improved self-care, indicating that the empowerment approach was a cost saving strategy. Although the empowerment approach was associated with a lower risk of ER attendance [IRR=0.55, 95% CI=0.31–0.95)] and hospital admission [IRR=0.38 (95% CI=0.31–0.95)], it is not cost saving for reducing hospital service utilization.

Conclusions

The empowerment-based self-care program is a cost-saving strategy to produce a clinical significant change in HF-related self-care. Although it is associated with lower risk for hospital service utilization, its effect is not significant enough to be cost-saving. Future care model may explore the need to integrate dyadic science [2] and e-health [3] to strengthen the care continuity and effects of self-care intervention.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health and Medical Research Fund, Food and Health Bureau, Hong Kong Special Administrative Region Figure 1

Impact of early initiation of SGLT2 inhibitor on cardiovascular outcomes in diabetic patients with known atherosclerotic cardiovascular disease or risk factors: propensity score matched analysis

Purpose

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have demonstrated cardiovascular benefits in patients with diabetes and atherosclerotic cardiovascular disease (ASCVD). We aimed to evaluate the impact of early initiation of SGLT2 inhibitor on cardiovascular outcomes in diabetic patients with known and at risk of ASCVD.

Methods

We retrospectively analyzed 29,309 consecutive patients with type 2 diabetes prescribed empagliflozin (N=18,979, 64.8%) and dapagliflozin (N=10,330, 35.2%) between August 2015 and August 2020 in 16 public hospitals in Hong Kong. Patients with diagnosis of diabetes to first prescription of SGLT2 inhibitors (Dx-to-Rx time) ≤12 months were matched with &gt;12 months using propensity score derived from logistic regression. 3,370 matched patients were divided into 4 groups: (i) patients with known ASCVD involving 1 territory (coronary artery, peripheral artery or cerebrovascular disease); (ii) known ASCVD involving &gt;1 territories; (iii) CV risk factor(s) other than diabetes and (iv) no known ASCVD or additional CV risk factors. Incidence rates of 3-point major adverse cardiovascular events (MACE, including non-fatal stroke, non-fatal myocardial infarction and cardiovascular death) were compared between Dx-to-Rx time ≤12 months and &gt;12 months across 4 subgroups during a median follow-up of 2.8 years (IQR 2.2 to 3.4).

Results

Of 29,309 patients (mean age 54.9±11.6 years, female 41.0%), 22.9% had single territory and 6.1% multi-territories ASCVD, 53.3% with additional CV risk factors and 17.7% neither risk factor nor ASCVD. Overall, 19.0% of patients had Dx-to-Rx time ≤12 month; 19.3%, 15.7%, 17.6% and 30.0% in each group, respectively. Overall, Dx-to-Rx time ≤12 months was associated with lower rates of MACE (hazard ratio (HR) =0.27, 95% CI: 0.17–0.42). Subgroup analysis showed similar results in patients with CV risk factors of or known ASCVD but not in patients with neither risk factor nor ASCVD (P for interaction=0.001, Table 1).

Conclusion

Early initiation of SGLT2 inhibitor was associated with significant lower MACE rates in diabetic patients with known ASCVD or additional CV risk factors. The impact was more marked in patients with additional CV risk factors. Our findings suggested early initiation in diabetic patients with known ASCVD and additional CV risk factors.

Funding Acknowledgement

Type of funding sources: None.

Strategies to bridge therapeutic gap in low-density-lipoprotein cholesterol lowering among 90,590 Chinese population with atherosclerotic cardiovascular diseases on stable statin monotherapy

Background

Current guideline recommends addition of PCSK9-inhibitor to achieve low-density-lipoprotein cholesterol (LDL-C) lowering by ≥50% to target LDL-C &lt;1.4mmol/L for patients with established atherosclerotic cardiovascular disease (ASCVD) already on maximum tolerated dose of statin and ezetimibe.

Purpose

We aimed to evaluate the residual distance to target LDL-C (LDL-C lowered by ≥50% and &lt;1.4mmol/L) in ASCVD patients on statin monotherapy and the proportion projected to reach target LDL-C by up-titration to high potency statin, addition of ezetimibe and PCSK9-inhibitor.

Methods

We retrospectively analyzed 90,590 patients with ASCVD on stable dose of statin monotherapy prior to lipid profile assessment from 43 public hospitals in Hong Kong between Aug 2016 and Jul 2020. Patients were divided into (i) high potency statin (HP-S; rosuvastatin ≥20mg, atorvastatin ≥40mg or simvastatin ≥80mg) and (ii) non-high potency statin (NHP-S; other statin doses) statin users. We calculated the mean percentage LDL-C reduction required to reach the target of LDL-C lowered by ≥50% and &lt;1.4mmol/L. We assumed up-titration from NHP-S to HP-S would further reduce LDL-C by approximately 5–10%; addition of ezetimibe 15–20% and PCSK-9 inhibitor 50–60%.

Results

Of 90,590 patients (63.2% male, mean age 66.8±11.3), 80.5% had coronary artery, 1.6% had peripheral artery and 21% had cerebrovascular disease; 18.7% were on HP-S and 81.3% on NHP-S. LDL-C lowered by ≥50% and &lt;1.4mmol/L were not achieved in 96.8% (n=71,333/73,655) patients on NHP-S and 93.9% (n=15,896/16,935) patients on HP-S. In these patients, mean LDL-C was 1.8±0.6 and 1.9±0.6mmol/L and mean percentage LDL-C reduction required to reach target LDL-C goal was 40.5±15.4% and 39.3±17.8%, respectively. The proportion of patients who required 5–10%, 10–30%, 30–60% and &gt;60% further reduction to reach target LDL-C were 2.5%, 22.1%, 65.4% and 9%, respectively. Proportion of NHP-S patients projected to reach LDL-C goal by up-titrating to HP-S is 2.2% (n=1,569/71,333). Addition of ezetimibe is projected to achieve LDL-C target in 20.5% (n=17,519/85,660) patients on HP-S who are not at goal. Overall, 78.1% (n=68,141/87,229) of patients on HP-S and ezetimibe were expected to need PCSK-9 inhibitor and is projected to achieve LDL-C target in 98% of cases (n=66,806/68,141).

Conclusion

Our “real-world” study showed the use of HP-S in ASCVD patients was low and &gt;90% did not reach LDL-C target. High potency statin plus ezetimibe was projected to bridge about one fifth of these patients to target LDL-C. PCSK-9 inhibitor is likely required in significant number of patients despite HP-S plus ezetimibe.

Funding Acknowledgement

Type of funding sources: None.

Potential benefits of ticagrelor plus aspirin in Chinese patients with stable coronary artery disease and diabetes

Purpose

Ticagrelor plus aspirin has been shown to reduce the incidence of cardiovascular (CV) events compared to asprin alone in patients with stable coronary artery disease and diabetes in the THEMIS trial. This study aimed to estimate the potential CV benefit of adding ticagrelor to aspirin among a THMEIS-like Chinese population.

Methods

We retrospectively analyzed 13,322 patients with stable coronary artery disease and diabetes from 16 public hospitals in Hong Kong between August 2015 and July 2020. 5,642 (42.4%) patients who met inclusion and exclusion criteria of the THEMIS trial were included in final analysis. Estimated absolute risk reduction (eARR) in major adverse CV event (MACE, composite of myocardial infarction (MI), ischemic stroke or CV death) and number needed to treat (eNNT) were extrapolated based on results of the THEMIS trial.

Results

Of 5,642 THEMIS-like patients (62.1% male; mean age 69.6±10.4 years), 26.5% had history of percutaneous coronary intervention (PCI). During a median follow-up of 17.5 (IQR: 9.3–41.3) months, rates of MACE, MI, stroke and CV-death were 10.7% (n=605), 5.3% (n=298), 2.5% (n=139) and 5.5% (n=308), respectively. Kaplan-Meier estimates at 36 months stratified by history of PCI or not were 16.9% vs. 14.0% for MACE and 9.0% vs 6.7% for MI (both Log-rank p&lt;0.01). Among THEMIS-like and THEMIS-PCI-like patients, eARR with ticagrelor plus aspirin was 1.4% (eNNT=71) and 1.6% (eNNT=63) for MACE and 1.5% (eNNT=67) and 1.9% (eNNT=53) for MI, respectively.

Conclusion

Approximately one third of Chinese patients with stable coronary artery disease and diabetes met THEMIS trial criteria. Combined therapy of ticagrelor and aspirin might provide similar clinical benefit in our population observed in the THEMIS trial, with low number needed to treat, especially in patients with previous PCI.

Funding Acknowledgement

Type of funding sources: None.

Single-cell transcriptome analysis yields new insights into the pathogenic mechanisms and possible genetic etiology of cardiomyopathies

Background

Inherited cardiomyopathies (CM) represent a clinically heterogeneous group of primary cardiac muscle disorders with a strong genetic underpinning. Recent rapid genomic advances have led to the identification of numerous disease-causing genes for both non-syndromic (nsCM) and syndromic (sCM) cardiomyopathies. This has greatly facilitated molecular genetic testing, thus enabling accurate disease diagnosis needed for the practice of precision medicine and the optimization of patient outcome. However, many cardiomyopathies remain unexplained with the known genes and dominant genetic model of disease.

Purpose

To reassess the genetic features of known CM genes as a strategy to recover novel candidate CM genes.

Methods

Known hypertrophic CM (HCM), dilated CM (DCM) and pediatric CM genes were curated from the literature and from 23 commercial CM diagnostic panels. They were classified as non-syndromic and syndromic, and further annotated using two constraint metrics, the missense Z score and pLI score obtained from the GnomAD database. Publicly available mouse (n=6) and human (n=3) single-cell RNA (scRNA) datasets were downloaded and cardiomyocyte specific differentially expressed genes (DEGs) (fold change &gt;0.1; adjusted P&lt;0.0001) were recovered. Genes identified as DEGs in at least 4 mouse or 3 human scRNA datasets were recovered as nsCM candidate genes.

Results

Analyses of 9 scRNA datasets showed the majority of known nsCM genes are cardiomyocyte specific (Fig. 1a-b). nsCM and sCM genes have distinct expression and genetic profile. nsCM genes are associated with higher heart expression and lower loss intolerance (Fig. 1c). In contrast, syndromic CM genes mostly showed lower expression with high loss intolerance, consistent with their higher clinical impact. However, interestingly some of the nsCM genes (MYLK2, TMPO and KLF10) show low or even no detectable expression in mouse and human cardiac cells. Using the scRNA data, we assessed cellular expression of genes in the 23 commercial CM diagnostic panels. This analysis showed some of the CM genes with high cardiomyocytes expression have low coverage on the current commercial CM panels (Fig. 1d). Using human and mouse scRNA data, we recovered 224 mouse and 157 human nsCM candidate genes. MTUS2 (microtubule-associated tumor suppressor candidate 2) was identified as a strong nsCM candidate gene supported by evidence from both mouse and human studies (Fig. 1e-f).

Conclusions

Our analysis showed many of the nsCM genes have differential cardiomyocyte expression with low loss intolerance, while the reverse was observed for many sCM genes. We propose increasing commercial panel coverage of cardiomyocytes-specific expressed genes may help increase disease diagnostic yield. Additionally, novel candidate genes uncovered trained on cardiomyocyte expression profile may help accelerate elucidation of unsolved cardiomyopathy cases.

Funding Acknowledgement

Type of funding sources: None.

[Short-term efficacy of anti-IgE monoclonal antibody in patients with recurrent chronic rhinosinusitis with nasal polyps combined with asthma]

Objective: To investigate the short-term efficacy of anti-IgE monoclonal antibody (Omalizumab) in the treatment of recurrent chronic rhinosinusitis with nasal polyps (CRSwNP) complicated with asthma. Methods: Patients with recurrent CRSwNP and comorbid asthma in Beijing TongRen Hospital from May to December of 2020 were continuously recruited and received a 4-month therapy of stable background treatment plus Omalizumab. Results of visual analog scales (VAS) of nasal symptoms, sino-nasal outcome test-22 (SNOT 22) and nasal polyp scores were collected at baseline and post-treatment (1, 2, 3 and 4 months after treatment). Blood routine tests, total nasal resistances (TNR), minimum cross-sectional areas (MCA), total nasal cavity volumes (NCV), forced expiratory volumes in one second (FEV1)/forced vital capacity (FVC) and adverse events were collected at baseline and 4 months after treatment. All results were evaluated for short-term efficacy of Omalizumab. GraphPad Prism 8.2.1 was used for statistic analysis. Results: Ten patients were collected, including 3 males and 7 females, aged (41.13±12.64) years old (x¯±s). Compared to results at baseline, the VAS scores of nasal obstruction, rhinorrhea, hyposmia and headache after 4 months treatment were significantly decreased (1.80±1.48 vs 6.70±2.83, 2.40±1.27 vs 6.40±3.44, 2.70±2.91 vs 8.20±2.25, 0.60±1.08 vs 3.60±2.72, t value was 5.045, 4.243, 5.312, 3.402, respectively, all P<0.01). The scores of SNOT-22 (25.6±20 vs 61.3±33.32, t=4.127, P=0.002 6), nasal polyp scores (2.20±0.92 vs 4.60±0.84, t=9.000, P<0.01) and the count and percentage of eosinophils in peripheral blood were significantly decreased ((94.10±97.78)×10⁹/L vs (360.00±210.80)×10⁹/L, (32.90±27.06)% vs (64.40±20.73)%, t value was 3.678, 2.957, respectively, all P<0.05). NCV (0-5 cm and 0-7 cm) of patients were improved from baseline ((12.62±2.84) cm³ vs (10.40±2.09) cm³, (27.50±14.15) cm³ vs (16.81±6.40) cm³, t value was 2.371, 2.445, respectively, all P<0.05). Conclusions: The 4-month treatment of Omalizumab can significantly improve the nasal symptoms and quality of life of patients with recurrent CRSwNP complicated with asthma, shrink nasal polyps size and reduce the number of peripheral blood eosinophils. Omalizumab can be used as an alternative therapy for refractory CRSwNP patients in the future.

Design and Multicenter Clinical Validation of a 3-Dimensionally Printed Nasopharyngeal Swab for SARS-CoV-2 Testing

Importance

Three-dimensionally printed nasopharyngeal swabs (3DP swabs) have been used to mitigate swab shortages during the coronavirus disease 2019 (COVID-19) pandemic. Clinical validation for diagnostic accuracy and consistency, as well as patient acceptability, is crucial to evaluate the swab's performance.

Objective

To determine the accuracy and acceptability of the 3DP swab for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Design, Setting, and Participants

A diagnostic study was conducted from May to July 2020 at 2 tertiary care centers in Singapore with different reference swabs (FLOQSwab [COPAN Diagnostics] or Dacron swab [Deltalab]) and swab processing techniques (wet or dry) to evaluate the performance of the 3DP swab compared with traditional, standard-of-care nasopharyngeal swabs used in health care institutions. The participants were patients with COVID-19 in the first 2 weeks of illness and controls with acute respiratory illness with negative test results for SARS-CoV-2. Paired nasopharyngeal swabs were obtained from the same nostril and tested for SARS-CoV-2 by reverse-transcriptase polymerase chain reaction. The sequence of swabs was randomized based on odd and even participant numbers.

Main Outcomes and Measures

Primary outcome measures were overall agreement (OA), positive percentage agreement (PPA), and negative percentage agreement of the 3DP swab compared with reference swabs. Secondary outcome measures were the correlation of cycle threshold (Ct) values of both swabs.

Results

The mean (SD) age of participants was 45.4 (13.1) years, and most participants were men (87 of 89 [97.8%]), in keeping with the epidemiology of the COVID-19 pandemic in Singapore. A total of 79 patients with COVID-19 and 10 controls were recruited. Among the patients with COVID-19, the overall agreement and PPA of the 3DP swab was 91.1% and 93.5%, respectively, compared with reference swabs. The PPA was 100% for patients with COVID-19 who were tested within the first week of illness. All controls tested negative. The reverse-transcriptase polymerase chain reaction Ct values for the ORF1ab and E-gene targets showed a strong correlation (intraclass correlations coefficient, 0.869-0.920) between the 3DP and reference swab on independent testing at each institution despite differences in sample processing. Discordant results for both gene targets were observed only at high Ct values.

Conclusions and Relevance

In this diagnostic study of 79 patients with COVID-19 and 10 controls, the 3DP swab performed accurately and consistently across health care institutions and could help mitigate strained resources in the escalating COVID-19 pandemic.

CNN-based qualitative detection of bone mineral density via diagnostic CT slices for osteoporosis screening

The features extracted from diagnostic computed tomography (CT) slices were used to qualitatively detect bone mineral density (BMD) through neural network models, and the evaluation results indicated that it may be a promising approach to perform osteoporosis screening in clinical practice.

INTRODUCTION

The purpose of this study is to design a novelty diagnostic method for osteoporosis screening by using the convolutional neural network (CNN), which can be incorporated into the procedure of routine CT diagnostic in medical examination thereby improving the osteoporosis diagnosis and reducing the patient burden.

METHODS

The proposed CNN-based method mainly comprises two functional modules to perform qualitative detection of BMD by analyzing the diagnostic 2D CT slice. The first functional module aims to locate and segment the ROI of diagnostic 2D CT slice, called Mark-Segmentation-Network (MS-Net). The second functional module is used to determine the category of BMD by the features of ROI, called BMD-Classification-Network (BMDC-Net). The diagnostic 2D CT slice of pedicle level in lumbar vertebrae (L1) was selected from 3D CT image in our experiments firstly. Then, the trained MS-Net can get the mark image of input original 2D CT slice, thereby obtain the segmentation image. Finally, the trained BMDC-Net can obtain the probability value of normal bone mass, low bone mass, and osteoporosis by inputting the segmentation image. On the basis of network results, the radiologists can provide preliminary qualitative diagnosis results of BMD.

RESULTS

Training of the network was performed on diagnostic 2D CT slices of 150 patients. The network was tested on 63 patients. Each patient corresponds to a 2D CT slice. The proposed MS-Net has an excellent segmentation precision on the shape preservation of different lumbar vertebra. The dice index (DI), pixel accuracy (PA), and intersection over union (IOU) of segmentation results are greater than 0.8. The proposed BMDC-Net achieved an accuracy of 76.65% and an area under the receiver operating characteristic curve of 0.9167.

CONCLUSIONS

This study proposed a novel method for qualitative detection of BMD via diagnostic CT slices and it has great potential in clinical applications for osteoporosis screening. The method can potentially reduce the manual burden to radiologists and diagnostic cost to patients.

[Effects of normobaric hyperoxia intervention on renal ischemia-reperfusion injury in rats]

Objective: To investigate the effects of normobaric hyperoxia intervention on renal ischemia-reperfusion injury in rats and its possible mechanism. Methods: Twenty-one adult male SD rats were enrolled and their right kidneys were excised. After two weeks, they were randomly assigned to 3 groups, with 7 rats in each group, namely sham-operated group (Group S), ischemia-reperfusion group (Group I/R), and normobaric hyperoxia+ischemia-reperfusion group (Group NBHO+I/R). In group S, only the left renal pedicle was isolated, but no ischemic treatment was performed. However, in group I/R and group NBHO+I/R, left renal pedicles were separated and left renal ischemia was induced by noninvasive arterial clamp for 45 min, and after 24 h of reperfusion, rats in group S and group I/R inhaled regular concentration of oxygen (21%), while rats in group NBHO+I/R inhaled high concentration of oxygen (60%), 2 h at each time, once a day for 7 days. On the 7th day after surgery, blood urea nitrogen (BUN) and creatinine (Cr) levels were measured by taking blood from the orbital veins of rats. The content of malondialdehyde (MDA) and superoxide dismutase (SOD) was detected from the left kidney tissues. The mRNA and protein contents of Keap1 and Nrf2 gene in kidney tissues were determined by qPCR and Western Blotting, respectively. Hematoxylin-eosin staining (HE) was employed to observe the pathological changes of kidney tissue. Immunohistochemical staining was used to measure the protein expression of Keap1 and Nrf2 in kidney tissues. Results: Compared with group S, the serum BUN [(10.7±1.7) mmol/L, (8.4±1.0) mmol/L vs (6.1±1.3) mmol/L, both P<0.05] and Cr [(81.0±3.7) μmol/L, (62.9±3.4) μmol/L vs (48.3±2.9) μmol/L, both P<0.05] levels of rats in the group I/R and group NBHO+I/R increased, and the I/R group had the most significant increase. Compared with group S, the MDA content of kidney tissue in the rats of group I/R and NBHO+I/R increased [(10.5±1.0) μmol/L, (8.6±0.8) μmol/L vs (6.5±0.5) μmol/L, both P<0.05], but the MDA content in group NBHO+I/R was lower than that of group I/R (P<0.05). Compared with group S, the SOD content in the kidney tissues of rats in both group I/R and group NBHO+I/R decreased. However, the SOD content of group NBHO+I/R was higher than that of group I/R (P<0.05). Compared with group S, the mRNA and protein contents of Keap1 gene in kidney tissues of group I/R and group NBHO+I/R decreased, and group NBHO+I/R had the most significant decrease (P<0.05). However, compared with group S, mRNA and protein expressions of Nrf2 gene increased in kidney tissues of group I/R and group NBHO+I/R, and NBHO+I/R group had the most significant increase (P<0.05). Postoperative pathological results suggested that compared with group S, the pathological damage of kidney tissues in group I/R and group NBHO+I/R increased, but the degree of damage in group NBHO+I/R was lower than that in group I/R. Conclusion: Normobaric hyperoxia intervention may have protective effects on renal ischemia-reperfusion injury in rats by activating Keap1-Nrf2 signaling pathway.

An engineered CRISPR-Cas12a variant and DNA-RNA hybrid guides enable robust and rapid COVID-19 testing

Extensive testing is essential to break the transmission of SARS-CoV-2, which causes the ongoing COVID-19 pandemic. Here, we present a CRISPR-based diagnostic assay that is robust to viral genome mutations and temperature, produces results fast, can be applied directly on nasopharyngeal (NP) specimens without RNA purification, and incorporates a human internal control within the same reaction. Specifically, we show that the use of an engineered AsCas12a enzyme enables detection of wildtype and mutated SARS-CoV-2 and allows us to perform the detection step with loop-mediated isothermal amplification (LAMP) at 60-65 °C. We also find that the use of hybrid DNA-RNA guides increases the rate of reaction, enabling our test to be completed within 30 minutes. Utilizing clinical samples from 72 patients with COVID-19 infection and 57 healthy individuals, we demonstrate that our test exhibits a specificity and positive predictive value of 100% with a sensitivity of 50 and 1000 copies per reaction (or 2 and 40 copies per microliter) for purified RNA samples and unpurified NP specimens respectively.

LINC00675 suppresses proliferative, migration and invasion of clear cell renal cell carcinoma via the Wnt/β-catenin pathway

OBJECTIVE

To clarify the role of LINC00675 in affecting the progression of clear cell renal cell carcinoma (ccRCC) and its potential mechanism, thus providing effective hallmarks and therapeutic targets for the clinical treatment of ccRCC.

MATERIALS AND METHODS

Differentially expressed long non-coding RNAs (lncRNAs) in renal epithelial tissues and ccRCC tissues were searched by analyzing the dataset downloaded from The Cancer Genome Atlas (TCGA) and LINC00675 was selected. LINC00675 level in ccRCC cell lines was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Overexpression model of LINC00675 model in 786-O and 769-P cells was constructed by the transfection of pcDNA3.1(+)-LINC00675 (LV-LINC00675). Changes in proliferative, migratory, and invasive capacities of 786-O and 769-P cells overexpressing LINC00675 were assessed. At last, relative levels of β-catenin, Vimentin, and N-cadherin in ccRCC cells overexpressing LINC00675 were detected by qRT-PCR and Western blot.

RESULTS

LINC00675 was downregulated in ccRCC tissues and cell lines. Overexpression of LINC00675 attenuated proliferative, migratory, and invasive capacities of 786-O and 769-P cells. Downregulation in β-catenin after overexpression of LINC00675, while Vimentin and N-cadherin levels did not change.

CONCLUSIONS

LINC00675 is downregulated in ccRCC. Overexpression of LINC00675 attenuates ccRCC to proliferate, migrate, and invade by activating the Wnt/β-catenin pathway.

LINC00114 promoted nasopharyngeal carcinoma progression and radioresistance in vitro and in vivo through regulating ERK/JNK signaling pathway via targeting miR-203

OBJECTIVE

Nasopharyngeal carcinoma (NPC) is a malignancy and is prone to distant metastasis and radioresistance. Long non-coding RNAs (lncRNAs) play vital roles in human cancers. The purpose of this study was to explore the role and the action mechanism of intergenic lncRNA (LINC00114) in NPC.

MATERIALS AND METHODS

The expression of LINC00114 and microRNA-203 (miR-203) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). NPC cells were exposed to X-ray as radiation treatment. Cell proliferation, migration, cell survival fraction and apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), transwell, colony formation, and flow cytometry assays, respectively. The expression of Cleaved-cas-3, Cleaved-cas-9, phosphor-ERK (p-ERK) and phosphor-JNK (p-JNK) was quantified by Western blot. The interaction between miR-203 and LINC00114 was predicted by bioinformatics tool microRNA.org and verified by dual-luciferase reporter assay. Tumor formation assay in nude mice was conducted to examine the role of LINC00114 in vivo.

RESULTS

LINC00114 was upregulated in serums from NPC patients, tissues and cell lines of NPC. LINC00114 knockdown inhibited proliferation, migration, and radioresistance of NPC cells. MiR-203 was a target of LINC00114, and miR-203 inhibition eliminated the effects of LINC00114 knockdown. Besides, the extracellular signal-regulated kinases (ERK)/c-Jun N-terminal kinases (JNK) pathway was inactivated by LINC00114 knockdown but recovered by miR-203 inhibition. Moreover, LINC00114 knockdown suppressed tumor growth and radioresistance in vivo.

CONCLUSIONS

LINC00114 contributed to NPC development and radioresistance through the regulation of ERK/JNK signaling pathway and the mediation of miR-203, suggesting that LINC00114 was a promising biomarker to defense NPC progression and radioresistance.

[Implementing and evaluating the online course system of orthodontic education]

A new teaching mode with the combination of online teaching and flipped class was designed and implemented in the Stomatological College of Nanjing Medical University based on the National Online Open Courses, the Virtual Interactive Network Teaching Platform and the E-learning Network Teaching Platform. The new online course system of orthodontic education was constructed with several components including the process and outcome assessments, the professional literature and knowledge summary reports and the virtual interactive online training. With the informative and convenient online teaching resources and modes, students' comprehensive abilities of independent learning were improved.

A134 A MULTI-CENTRE RANDOMIZED CONTROLLED TRIAL TO COMPARE TWO BOWEL CLEANSING REGIMENS AFTER A COLONOSCOPY WITH INADEQUATE BOWEL PREPARATION

Aims

Failed bowel preparation is common during colonoscopy, yet the optimal purgative regimen to use for the next attempt is unknown. The objective of this study was to compare the efficacy, tolerability, and safety of two regimens at supratherapeutic doses for use after failed bowel preparation.

Methods

A multi-centre phase III endoscopist blinded randomized controlled trial (NCT02976805) was conducted in patients who failed bowel preparation, using the US Multi-Society Task Force (USMSTF) definition of inability to exclude polyps &gt;5 mm in size and requiring a shortened interval to next colonoscopy. Regimen A consisted of 15 mg of bisacodyl and 2 + 2 L of split dose polyethylene glycol electrolyte solution (PEG) and Regimen B consisted of 15 mg of bisacodyl and 4 + 2 L of split dose PEG. The primary outcome was adequate bowel preparation, defined as a Boston Bowel Preparation Scale (BBPS) total score ≥ 6 with all segment scores ≥ 2. Secondary outcomes were adequate bowel preparation using the USMSTF definition, median BBPS, adenoma detection (ADR), advanced adenoma detection (aADR), sessile serrated polyp detection (SSPDR), and cecal intubation (CIR). Adverse events were assessed at the time of the colonoscopy and 14 days later.

Results

Between February 2017 and December 2019, 250 subjects were screened at four academic centres in Canada, of which 195 were randomized: 96 to Regimen A and 99 to Regimen B. The mean (SD) age was 60.6 (11.4) years, 87 (45.1%) were female, and the median (IQR) total BBPS score at previous failed colonoscopy was 3 (1,4). Regimen B was not superior to Regimen A in achieving adequate bowel preparation using the BBPS definition (87.6% vs. 91.1%, p=0.45) or the USMSTF definition (85.4% vs 91.1%, p=0.24), nor was it superior with respect to the median BBPS score (7 vs 7, p=0.50), mean ADR (31.5% vs 37.8%, p=0.37), aADR (11.2% vs 18.9%, p=0.15), SSPDR (5.6% vs 8.9%, p=0.40) or CIR (92.1% vs 96.7%, p=0.19). Regimen A had a higher adherence rate (88.2% vs. 74.7%, p=0.02) and greater willingness to undergo the bowel preparation again (91.2% vs. 66.2%, p&lt;0.001). The only serious adverse event occurred in a patient randomized to Regimen B who was admitted to hospital for vomiting after colonoscopy.

Conclusions

Split dose 4L PEG with 15mg of bisacodyl is highly efficacious, well tolerated, and can be used for patients who previously failed first line bowel preparations. The additional 2L of PEG in Regimen B did not improve bowel preparation and was not as well tolerated.

Funding Agencies

AMOSO Opportunities Grant, Pharmascence Inc.

A108 ARE INPATIENTS STILL MORE LIKELY TO FAIL BOWEL PREPARATION IN THE SPLIT-DOSE ERA? FINDINGS FROM 47, 292 COLONOSCOPIES IN THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Background

Prior studies before the widespread use of split-dose bowel preparation have shown a high rate of inadequate bowel preparation in hospitalized patients. Whether this is still true in the era of split-dose bowel preparation is unknown.

Aims

To determine the impact of inpatient status on bowel preparation quality in the contemporary era of split-dose bowel preparation.

Methods

The Southwest Ontario Colonoscopy cohort consists of all inpatient and outpatient colonoscopies performed between April 2017 and Oct 2018 at 21 hospitals serving a large geographic health region. Procedures done in patients &lt; 18 years of age or by an endoscopist performing &lt;50 colonoscopies/year were excluded. Data were collected through a mandatory quality assurance form that was completed by the endoscopist after each procedure. Pathology reports were manually reviewed. The primary outcome was adequate bowel preparation, defined on an ordinal scale as “good” or “fair” rather than “poor”. Secondary outcomes included adenoma detection rate (ADR), sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), and cecal intubation rate (CIR).

Results

A total of 47,292 colonoscopies were performed by 75 physicians (36.2% by gastroenterologists, 60% by general surgeons, 4% others), of which 1,690 were inpatients (3.6%). Inpatients were older (mean 66.8 years vs 60.2 years, p&lt;0.0001), more co-morbid (≥ASA grade 3, 53.6% vs 23.7%, p&lt;0.0001), performed for symptomatic indications (95.7% vs 48.6%, p&lt; 0.0001), have trainee involvement (47% vs 11.6% p&lt;0.001), and less likely to receive split-dose bowel preparation (71.7% vs 91.6% p&lt;0.001). On crude analysis, inpatients were less likely to have adequate bowel preparation (86.2% vs 97.6% p&lt;0.001). On multi-variable analysis, inpatients had lower odds of achieving adequate bowel preparation (OR=0.41, 95% CI 0.33 - 0.50, p&lt;0.001), lower ADR (OR=0.47, 95% CI 0.40 - 0.55, p&lt;0.001), lower PDR (OR=0.54, 95% CI 0.47 - 0.61 p&lt;0.001) and lower CIR (OR = 0.43, 95% CI 0.35 - 0.54, p&lt;0.001).

Conclusions

In the era of split-dose bowel preparation, inpatient status is still an important predictor of inadequate bowel preparation with resultant lower quality outcome metrics.

Funding Agencies

None

A113 ANNUAL COLONOSCOPY VOLUME IS NOT PREDICTIVE OF COLONOSCOPY QUALITY - FINDINGS FROM THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Background

Performing a minimum number of colonoscopies annually has been proposed by some jurisdictions as a requirement for maintaining privileges. However, this practice is supported by limited evidence.

Aims

The objective of this study was to determine if annual colonoscopy volume was associated with colonoscopy quality metrics.

Methods

A population-based study was performed using the Southwest Ontario Colonoscopy cohort, which consists of all adult patients who underwent colonoscopy between April 2017 and Oct 2018 at 21 academic and community hospitals within the health region. Data were collected through a mandatory quality assurance form completed after each procedure and pathology reports were manually reviewed. Physician annualized colonoscopy volumes were compared by correlation analysis to each quality-related outcome, by means of the area under the receiver operating characteristics curve (AUROC), and logistic regression. The prognostic value of colonoscopy volume was also adjusted for case-mix and potential confounders in separate regression analyses for each outcome. The primary outcome was ADR. Secondary outcomes were polyp detection rate (PDR), sessile serrated polyp detection rate (SSPDR), and cecal intubation.

Results

A total of 47,195 colonoscopies were performed by 75 physicians (37.5% by gastroenterologists, 60% by general surgeons, 2.5% others). There were no clear relationships between annual colonoscopy volumes and study outcomes. Colonoscopy volume was not associated with ADR (OR 1.03, 95% CI 0.96–1.10, p=0.48) and corresponded to an AUROC not significantly different from the null (AUROC 0.52, 95% CI 0.43–0.61, p=0.65). Multi-variable regression adjusting for case-mix also demonstrated no predictive value of annual colonoscopy volume for the primary outcome (OR 1.03, 95% CI 0.94–1.12, p=0.55). Similarly, analyses of secondary outcomes failed to find an association between colonoscopy volume and PDR, SSPDR, or cecal intubation (Table 1).

Conclusions

Annual colonoscopy volumes do not predict ADR, PDR, SSPDR, or cecal intubation rate.

Results of unconditional and conditional approaches for examining the predictive value of annual colonoscopy volume for quality related outcomes.

Funding Agencies

None

A117 PROPOFOL SEDATION DOES NOT IMPROVE MEASURES OF COLONOSCOPY QUALITY – FINDINGS FROM THE SOUTHWEST ONTARIO COLONOSCOPY COHORT

Background

The use of propofol during colonoscopy has gained increased popularity due to deeper anesthesia compared to conscious sedation. Prior studies examining the use of propofol sedation during colonoscopy have primarily focused on anesthesia outcomes. Whether propofol sedation is associated with improvements in colonoscopy outcomes is uncertain.

Aims

The primary outcome was adenoma detection rate (ADR). Secondary outcomes were the detection of any adenoma (conventional adenoma, sessile serrated polyp, and traditional serrated adenoma), sessile serrated polyp detection rate, polyp detection rate, cecal intubation rate, and perforation rate.

Methods

The Southwest Ontario Colonoscopy cohort consists of all patients who underwent colonoscopy between April 2017 and Oct 2018 at 21 hospitals serving a large geographic area in Southwest Ontario. Procedures performed in patients less than 18 years of age or by endoscopist who perform &lt;50 colonoscopies/year were excluded. Data were collected through a mandatory quality assurance form that was completed by the endoscopist after each procedure. Pathology reports were manually reviewed.

Results

A total of 46,634 colonoscopies were performed by 75 physicians (37.5% by gastroenterologists, 60% by general surgeons, 2.5% others) of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation (e.g. combination of a benzodiazepine and a narcotic). Patients who received propofol were likely to have a screening indication (49.2% vs 45.5%, p&lt;0.0001), not have a trainee endoscopist present and be performed at a non-academic centre (32.2% vs 44.6%, p&lt;0.0001). Compared to conscious sedation, use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p&lt;0.0001) and detection of any adenoma (27.7% vs. 29.8%, p&lt;0.0001); no difference was observed in the detection ofsessile serrated polyps (5.0% vs. 4.7%, p=0.26), polyp detection rate (41.2% vs 41.2%, p=0.978), cecal intubation rate (97.1% vs. 96.8%, p=0.15) or perforation rate (0.04% vs. 0.06%,p=0.45). On multi-variable analysis, the use of propofol was not significantly associated with any improvement in ADR (RR=0.90, 95% CI 0.74–1.10, p=0.30), detection of any adenoma (RR=0.93, 95% CI 0.75–1.14, p=0.47), sessile serrated polyp detection rate (RR=1.20, 95%CI 0.90–1.60, p=0.22), polyp detection rate (RR=1.00, 95% CI 0.90–1.11, p=0.99), or cecal intubation rate (RR=1.00, 95%CI 0.80–1.26, p=0.99).

Conclusions

The use of propofol sedation does not improve colonoscopy quality metrics.

Funding Agencies

None

A12 PRE-TREATMENT HLADQA1-HLADRB1 TESTING FOR THE PREVENTION OF AZATHIOPRINE-INDUCED PANCREATITIS IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Azathioprine (AZA) therapy has a long history of use in IBD. The need to promote its safe use in this population is ensured by governmental health policy requiring IBD patients to fail low cost drugs, such as AZA, prior to approving funding for more potent biologic therapies. AZA-induced pancreatitis is an idiosyncratic and unpredictable response, occurring in up to 7% of AZA-exposed patients that can lead to patient morbidity, hospitalization, delay in effective IBD management, as well as result in substantial additional health-related costs. There are no tools in clinical practice to identify individuals at risk of AZA-induced pancreatitis. Genetic variation in the HLADQA1-HLADRB1*07:01 haplotype is strongly associated with azathioprine (AZA)-induced pancreatitis in inflammatory bowel disease (IBD).

Aims

To evaluate whether HLA DQA1-HLADRB1*07:01A&gt;C pre-treatment genotype testing in an adult IBD population prior to AZA therapy to guide AZA selection would result in a lower incidence of AZA-induced pancreatitis.

Methods

Participants with IBD (n=599) were screened for HLADQA1-HLADRB1*07:01A&gt;C and participants with a variant genotype were excluded from azathioprine treatment (n=271). Wildtype participants (n=328) were started on azathioprine and followed for 3 months. The incidence of pancreatitis was compared to unscreened historical controls (n=373).

Results

The minor allele frequency of HLADQA1-HLADRB1*07:01 was 30.4% and 30.0% in the screened and unscreened populations respectively. Up to 45.2% of participants were excluded from AZA therapy based on genotype in the HLADQA1-HLADRB1*07:01A&gt;C screened cohort. HLADQA1-HLADRB1*07:01A&gt;C screening resulted in an 11-fold reduction in the odds of azathioprine-induced pancreatitis (0.30% versus 3.4%, OR=0.085, 95%CI=0.011–0.651, p=0.002).

Conclusions

HLA DQA1-HLADRB1*07:01A&gt;C screening substantially reduced the risk of pancreatitis during AZA treatment in patients with IBD. However, using this strategy as a tool for guiding the use of AZA therapy in IBD may eliminate a large proportion of patients from being eligible for treatment with AZA. In regions, where there is access to other IBD therapies, and given the short and long term toxicities associated with AZA, HLA DQA1-HLADRB1*07:01A&gt;C screening may be a clinically-relevant strategy for enhancing the safe use of AZA in IBD. Additionally, cost-effectiveness analyses are needed to further solidify the utility of HLA DQA1-HLADRB1*07:01A&gt;C-screening in IBD populations.

Funding Agencies

Academic Medical Organization of Southwestern Ontario Innovation Fund

A120 NO EVIDENCE OF A FRIDAY EFFECT ON COLONOSCOPY QUALITY OUTCOMES

Background

Colonoscopy quality may be influenced by operator fatigue. Prior studies have shown lower adenoma detection rates for procedures performed at the end of the day. However, it is unknown if colonoscopy quality is impaired at the end of the work week.

Aims

We investigated whether colonoscopy quality-related metrics differ at the end of the work week using the South West Ontario Colonoscopy Cohort.

Methods

Between April 2017 to February 2018, 45,510 consecutive colonoscopies from 20 academic and community hospitals in our health region were captured to form the cohort. In Canada, outpatient endoscopies are generally performed between Monday to Friday, taking Friday, or the last business day, as the last day of the work week compared to the rest of the work week. When a statutory holiday occurred on a Friday, Thursday was designated the last day of the work week. The primary outcome was adenoma detection rate (ADR), and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), and failed cecal intubation. Outcomes were presented as unadjusted and adjusted risk ratios derived from modified Poisson regression and adjusting for physician-level clustering, and characteristics of the patient (age, sex, severity), procedure (hospital setting, trainee presence, indication, sedation, bowel preparation quality) and physician (experience and specialty).

Results

During the observation period, 9,132 colonoscopies were performed on the last day of the work week compared to 36,378 procedures during the rest of the work week. No significant difference was observed for ADR (26.4% vs. 26.6%, p=0.75), ssPDR (4.5% vs. 5.0%, p=0.12), PDR (44.1% vs. 43.1%, p=0.081), or failed cecal intubation (2.8% vs. 2.9%, p=0.51) for colonoscopies performed on the last day of the work week compared to the rest of the week, respectively. After adjusting for potential confounders, there were no significant differences in the ADR (RR 1.01, 95% CI [0.88, 1.15], p=0.94), ssPDR (RR 0.90, 95% CI [0.70, 1.14], p=0.38), PDR (RR 1.00, 95% CI [0.92, 1.09], p=0.94), or failed cecal intubation (RR 0.92, 95% CI [0.72, 1.18], p=0.51) for colonoscopies performed on the last day of the work week compared to the rest of week, respectively.

Conclusions

Colonoscopy quality metrics, including ADR, ssPDR, PDR, and failed cecal intubation are not significantly different at the end of the week.

Funding Agencies

None

Clinical Diagnostic Study of a Novel Injection Molded Swab for SARS-Cov-2 Testing

Introduction

The gold standard for COVID-19 diagnosis is currently a real-time reverse transcriptase polymerase chain reaction (RT-PCR) to detect SARS-CoV-2. This is most commonly performed on respiratory secretions obtained via a nasopharyngeal swab. Due to supply chain limitations and high demand worldwide because of the COVID-19 pandemic, access to commercial nasopharyngeal swabs has not been assured. 3D printing methods have been used to meet the shortfall. For longer-term considerations, 3D printing may not compare well with injection molding as a production method due to the challenging scalability and greater production costs of 3D printing.

Methods

To secure sufficient nasopharyngeal swab availability for our national healthcare system, we designed a novel injection molded nasopharyngeal swab (the IM2 swab). We performed a clinical diagnostic study comparing the IM2 swab to the Copan FLOQSwab. Forty patients with a known diagnosis of COVID-19 and 10 healthy controls were recruited. Paired nasopharyngeal swabs were obtained from the same nostril of each participant and tested for SARS-CoV-2 by RT-PCR.

Results

When compared to the Copan FLOQswab, results from the IM2 swab displayed excellent overall agreement and positive percent agreement of 96.0% and 94.9%, respectively. There was no significant difference in mean RT-PCR cycle threshold values for the ORF1ab (28.05 vs. 28.03, p = 0.97) and E-gene (29.72 vs. 29.37, p = 0.64) targets, respectively. We did not observe any significant adverse events and there was no significant difference in patient-reported pain.

Conclusion

In summary, the IM2 nasopharyngeal swab is a clinically safe, highly accurate option to commercial nasopharyngeal swabs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-020-00391-6.

Pregnancy Outcomes in COVID-19: A Prospective Cohort Study in Singapore

INTRODUCTION

Pregnant women are reported to be at increased risk of severe coronavirus disease 2019 (COVID-19) due to underlying immunosuppression during pregnancy. However, the clinical course of COVID-19 in pregnancy and risk of vertical and horizontal transmission remain relatively unknown. We aim to describe and evaluate outcomes in pregnant women with COVID-19 in Singapore.

METHODS

Prospective observational study of 16 pregnant patients admitted for COVID-19 to 4 tertiary hospitals in Singapore. Outcomes included severe disease, pregnancy loss, and vertical and horizontal transmission.

RESULTS

Of the 16 patients, 37.5%, 43.8% and 18.7% were infected in the first, second and third trimesters, respectively. Two gravidas aged ≥35 years (12.5%) developed severe pneumonia; one patient (body mass index 32.9kg/m2) required transfer to intensive care. The median duration of acute infection was 19 days; one patient remained reverse transcription polymerase chain reaction (RT-PCR) positive >11 weeks from diagnosis. There were no maternal mortalities. Five pregnancies produced term live-births while 2 spontaneous miscarriages occurred at 11 and 23 weeks. RT-PCR of breast milk and maternal and neonatal samples taken at birth were negative; placenta and cord histology showed non-specific inflammation; and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunoglobulins were elevated in paired maternal and umbilical cord blood (n=5).

CONCLUSION

The majority of COVID-19 infected pregnant women had mild disease and only 2 women with risk factors (obesity, older age) had severe infection; this represents a slightly higher incidence than observed in age-matched non-pregnant women. Among the women who delivered, there was no definitive evidence of mother-to-child transmission via breast milk or placenta.

Dose-response relationship between serum fibroblast growth factor 21 and liver fat content in non-alcoholic fatty liver disease

BACKGROUND & AIM

Although serum fibroblast growth factor 21 (FGF21) levels are associated with liver fat content in non-alcoholic liver fat disease (NAFLD), the precise nature of the association remains undetermined. Therefore, this study aimed to explore the potential dose-response relationship between FGF21 and liver fat content in NAFLD.

METHODS

For this exploratory study from a randomized trial, 220 NAFLD patients with central obesity were recruited via community-based screening and randomly assigned to either control, moderate or vigorous-moderate exercise groups for 12 months. After this exercise intervention, patients were followed-up for a further 12 months. Serum FGF21 levels were measured by ELISA. Intrahepatic triglyceride (IHTG) content was determined by proton magnetic resonance spectroscopy.

RESULTS

Of the 220 patients, 149 (67.7%) were female; mean age was 53.9 ± 7.1 years and mean BMI was 28.0 ± 2.9 kg/m² for all patients. Baseline IHGT increased gradually (P = 0.029 for trend) according to baseline serum FGF21 quartiles 1, 2, 3 and 4 (212.3, 358.9, 538.7 and 793.5 pg/mL, respectively). On grouping the distribution of serum FGF21 level changes into quartiles at month 12, the relative IHTG loss increased as serum FGF21 levels were reduced (P = 0.004 for trend). A similar trend was observed at month 24 (P = 0.006 for trend). Multivariate linear regression analysis revealed that changes in serum FGF21 levels were independently associated with changes in IHTG at both month 12 [β (SE), 0.136 (0.118); P = 0.048] and month 24 [β (SE), 0.152 (0.139); P = 0.041]. Using restricted cubic spline regression, changes in serum FGF21 were strongly and positively associated with their corresponding relative IHTG loss at both month 12 and follow-up (P_overall = 0.017, P_non-linear = 0.044 and P_overall = 0.020, P_non-linear = 0.361, respectively, for dose-response).

CONCLUSION

Serum FGF21 is strongly associated with liver fat content in a dose-response manner in centrally obese NAFLD patients. These findings support the use of serum FGF21 as a biomarker of liver fat content in NAFLD.