Fragile topology in double-site honeycomb lattice photonic crystal

Fragile topology (FT) opens a new direction in topological photonics, but a new type of photonic crystal (PC) with FT remains to be proposed. In this Letter, the double-site honeycomb lattice (DSHL) PC is proposed by rotating the double dielectric rods (DDR) six times, forming unit cell, and then arraying the unit cells in a triangular lattice. Quantum spin Hall effect occurs by manipulating the DDR in the tangential and radial directions of the unit cell. First, the band structures of DSHL PCs with different structural parameters are calculated, and the laws of topological phase transition are analyzed statistically. Then, to prove the FT properties of two groups of topological nontrivial DSHL PCs, the Wannier-center positions of the bulk bands are calculated by the Wilson-Loop method. Finally, the topological edge states and two groups of topological corner states, which are in the same bulk-state bandgap, are realized successfully. The DSHL PC provides good platforms for both the research of topological photonics and the device design and application, which has a broad prospect.

STXM-XANES and computational investigations of adsorption of per- and polyfluoroalkyl substances on modified clay

The study investigated molecular mechanisms of per- and polyfluoroalkyl substances (PFAS) on a surfactant modified clay (SMC), which rivals or exceeds the performance of granular activated carbon in removing long-chain PFAS from contaminated water. The adsorption isotherms of four anionic and one neutral PFAS from 1 × 10^-9 to 1 × 10^-5 mol/L were measured to be piecewise, accompanied by the expansion of the SMC interlayer. Based on the spatial distribution of perfluorocarboxylic acid (PFOA) on SMC at the submicron scale, achieved by synchrotron-based scanning transmission X-ray microscopy (STXM) coupled with X-ray absorption near-edge structure spectroscopy (XANES), PFOA molecules were confirmed to enter the interlayer space of SMC and could form charge-charge interaction with the intercalants (quaternary ammonia cations). Revealed by the all-atom molecular dynamics (MD) simulation and density functional theory-based quantum calculations, the interactions between the positively charged surfactant and representative PFAS include charge-charge, charge-dipole, and dipole-dipole interactions. The adsorption mechanisms vary from one PFAS structure to another in terms of adsorption energy and spatial arrangement. Those interactions overcome the interaction between PFAS and water, allowing PFAS to be retained in the SMC's interlayer space. The study provides fundamental insights into how PFAS interact with clay-based materials, supporting the use of the materials for PFAS treatment and remediation.

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.

Maternal high-fructose consumption provokes placental oxidative stress resulting in asymmetrical fetal growth restriction in rats

We aimed to determine the impact of high-fructose intake during pregnancy on the fetal-placental unit in rats, which may be the initial mechanism of the programming effect of fructose. Pregnant Sprague–Dawley rats were randomly assigned to three groups and respectively provided tap water (n = 10), 10% (w/v) fructose solution (n = 10), and 10% (w/v) glucose solution (n = 10) from embryonic day 0 to 20. Compared with the control and glucose groups, significantly lower fetal length, fetal weight, placental weight, and fetus/placenta ratio were found in the fructose group on embryonic day 20 (all p<0.05). In parallel with markedly increased uric acid concentrations in the dams, significantly decreased antioxidant enzymes activities and mRNA expression levels were observed in placentas in the fructose group (all p<0.05). In the fructose group, placental mRNA and protein expression of nuclear factor erythroid 2-related factor 2 was markedly downregulated and kelch-like ECH-associated protein 1 was significantly upregulated (all p<0.05). In conclusion, high-fructose consumption during pregnancy drives augmented oxidative stress in rats. Placental insufficiency under oxidative stress contributes to asymmetrical fetal growth restriction.

Inhibition of xCT suppresses the efficacy of anti-PD-1/L1 melanoma treatment through exosomal PD-L1-induced macrophage M2 polarization

Tumor cells increase glutamate release through the cystine/glutamate transporter cystine-glutamate exchange (xCT) to balance oxidative homeostasis in tumor cells and promote tumor progression. Although clinical studies have shown the potential of targeting programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) signaling in melanoma, response rates are low. However, it remains unclear how glutamate metabolism affects anti-PD-1/PD-L1 treatment efficacy in melanoma. Here, we demonstrated that although inhibition of xCT either by pharmacological inhibitor (sulfasalazine [SAS]), approved by US Food and Drug Administration (FDA) for inflammatory diseases, or genetic knockdown induced reactive oxygen species (ROS)-related death in melanoma cells, inhibition of xCT significantly reduced the efficacy of anti-PD-1/PD-L1 immune checkpoint blockade through upregulating PD-L1 expression via the transcription factors IRF4/EGR1, as a consequence, exosomes carrying relatively large amounts of PD-L1 secreted from melanoma cells resulted in M2 macrophage polarization and reduced the efficacy of anti-PD-1/PD-L1 therapy in melanoma. Taken together, our results reveal that inhibition of xCT by SAS is a promising therapeutic strategy for melanoma; on the other hand, SAS treatment blunted the efficacy of anti-PD-1/PD-L1 via exosomal PD-L1-induced macrophage M2 polarization and eventually induced anti-PD-1/PD-L1 therapy resistance.

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

Coupled cavity-waveguide based on topological corner state and edge state

The topological corner state (TCS) and topological edge state (TES) have created new approaches to manipulate the propagation of light. The construction of a topological coupled cavity-waveguide (TCCW) based on the TCS and TES is worth looking forward to, due to its research prospects in realizing high-performance micro-nano integrated photonic devices. In this Letter, the TCCW is proposed in two-dimensional (2D) photonic crystal (PC), which possesses strong optical localization, high quality factor, and excellent robustness compared with the conventional coupled cavity-waveguide (CCCW). This work will pave the way toward designing high-performance logic gates, lasers, filters, and other micro-nano integrated photonics devices and expanding their applications.

Efficacy and safety of Chinese herbal medicine versus Lopinavir-Ritonavir in adult patients with coronavirus disease 2019: A non-randomized controlled trial

BACKGROUND

Treatments for coronavirus disease 2019 (COVID-19) are limited by suboptimal efficacy.

METHODS

From January 30, 2020 to March 23, 2020, we conducted a non-randomised controlled trial, in which all adult patients with laboratory-confirmed COVID-19 were assigned to three groups non-randomly and given supportive treatments: Group A, Lopinavir-Ritonavir; Group B, Huashi Baidu Formula (a Chinese medicineformula made by the China Academy of Chinese Medical Sciences to treat COVID-19, which is now in the clinical trial period) and Lopinavir-Ritonavir; and Group C, Huashi Baidu Formula. The use of antibiotics, antiviruses, and corticosteroids was permitted in Group A and B. Traditional Chinese medicine injections were permitted in Group C. The primary outcomes were clinical remission time (interval from admission to the first time the patient tested negatively for novel coronavirus or an obvious improvement was observed from chest CT) and clinical remission rate (number of patients whose clinical time was within 16 days/total number of patients).

RESULTS

A total of 60 adult patients with COVID-19 were enrolled at sites in Wuhan, China, and the sample size of each group was 20. In Groups A, B and C, the clinical remission rates were 95.0%%(19/20), 100.0%%(20/20) and 100.0%%(20/20), respectively. Compared with Groups A and B, the clinical remission time of Group C was significantly shorter (5.9 days vs. 10.8 days, p < 0.05; 5.9 days vs. 9.7 days, p < 0.05). There was no significant difference among Groups A, B, and C in terms of the time taken to be released from quarantine. The clinical biochemical indicators and safety indexes showed no significant differences among the three groups.

CONCLUSIONS

Our findings suggest that Lopinavir-Ritonavir has some efficacy in the treatment of COVID-19, and the Huashi Baidu Formula might enhance this effect to an extent. In addition, superiority was displayed in the treatment of COVID-19 through a combination of the Huashi Baidu Formula and traditional Chinese medicine injection. In future, well-designed prospective double-blinded randomised control trials are required to confirm our findings.

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.

Communication in Transactive Memory Systems: A Review and Multidimensional Network Perspective

The comprehensive review synthesizes 64 empirical studies on communication and transactive memory systems (TMS). The results reveal that (a) a TMS forms through communication about expertise; (b) as a TMS develops, communication to allocate information and coordinate retrieval increases, promoting information exchange; and (c) groups update their TMS through communicative learning. However, direct interpersonal communication is not necessary for TMS development or utilization. Nor do high-quality information-sharing processes always occur within developed TMS structures. For future research, we propose a multidimensional network approach to TMS that incorporates technologies, addresses member characteristics, considers multiple communication types, and situates groups in context.

Protective Effects of Nucleosides-Rich Extract from Cordyceps cicadae against Cisplatin Induced Testicular Damage

Cisplatin (CISP) is an efficacious anticancer agent used in chemotherapy, however, the constraint to its clinical utility is the stray organ toxicity including testicular damage linked to oxidative and inflammatory cascades. This study aimed to explore the protective effect of nucleosides-rich extract from Cordyceps cicadae (NRCE) against CISP-induced testicular damage in rats. Rats were subjected to prophylactic oral administration of NRCE (50, 100 and 400 mg/kg body weight/day) for 7 days prior to testicular toxicity induced by CISP (10 mg/kg, ip) and were sacrificed after 72 h post-CISP injection. Cisplatin caused significant deficits in sperm count, viability and motility, testosterone and follicle stimulating hormone (FSH) compared to normal control. It depressed testicular activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), total antioxidant content (TAC), whereas malondialdehyde (MDA) increased remarkably. CISP considerably increased tumor necrosis factor-alpha (TNF-α) and interleukin-one beta (IL-1β) with alterations in testis histology compared to normal control. Interestingly, NRCE pretreatment inhibited the CISP-induced alterations in reproductive indices, restored the antioxidant activities in testes as well as inflammatory mediators and histology comparable to control. Our findings demonstrate that NRCE could prevent CISP testicular damage via inhibition of oxidative stress and pro-inflammation in rats.

Molecular mechanisms of per- and polyfluoroalkyl substances on a modified clay: a combined experimental and molecular simulation study

Repeated application of aqueous film-forming foams (AFFF) in designated firefighting training areas has caused severe groundwater contamination by per- and polyfluoroalkyl substances (PFASs). Many research efforts are currently engaged for the effective removal of these chemicals from environmental waters. In this study, we demonstrate that modified clay produced by intercalating quaternary ammonium cations in the exchangeable interlayer sites of smectite clay can effectively remove PFAS pollutants in real groundwater via strong adsorption. The performance of the modified clay (with removal efficiencies 95~99%) is superior to those of granular activated carbon or hard-wood biochar and comparable to an ion exchange resin. Removal efficiency is not impacted by potential organic co-contaminants (e.g., diesel, BTEX, TCE, and 1,4 dioxane) or water chemistry (Ca²⁺ and Na⁺) at environmentally relevant concentrations. Furthermore, piecewise isotherms are identified to represent the uptake of PFASs by the modified clay. Based on molecular dynamics simulations, the anionic PFASs first occupy the highly polarized bare interlayer edge sites leading to a linear isotherm and then the interlayer surface sites resulting in a Langmuir isotherm. The ionic interactions between the cationic intercalant (N⁺) and the terminal oxygen atoms of carboxylate or sulfonate groups of PFASs play a dominant role in adsorption, and the lateral interaction in particular fluorophilic attraction among PFASs accelerate the adsorption. The strength of these interactions is quantified using Density Functional Theory calculations. Simulation results match reasonably well with the experimentally determined basal spacing and Fourier transform infrared spectroscopy of the modified clay loaded with PFASs. Overall, the combined experimental and molecular simulation studies elucidate the adsorption mechanism of PFASs on the modified clay and provide critical information to guide the use of modified clays for PFAS water treatment in the field.

Inhibitory effect of Lycium barbarum polysaccharide on sperm damage during cryopreservation

With the development of cryopreservation technology, marked progress has been made regarding sperm cryopreservation. However, as conventional cryopreservation agents are not effective at freezing weak sperm, improved cryopreservation agents are in demand. In the present study, the addition of Lycium barbarum polysaccharides to glycerol-egg-yolk-citrate sperm cryopreservation agent was determined to improve sperm forward speed, reduce the DNA fragmentation index and improve the mitochondrial membrane potential. Furthermore, during the freezing and thawing of sperm, the improved cryopreservative increased the content of Bcl-2 while reducing the content of Bax, cytochrome C and caspase-3. These results indicated that polysaccharides added as a protective agent preserved the normal function of sperm mitochondria. Transmission electron microscopy also confirmed the protective effect of the polysaccharides on the structure of mitochondria. It was also indicated that improved cryopreservative lowered the levels of reactive oxygen species (ROS) during the freeze-thawing process. Therefore, it is hypothesized that improved cryopreservative agents may be beneficial for maintaining the structure and function of the mitochondria of weak sperm when cryopreserved, which may be facilitated via reducing the production of ROS in the freezing-thawing process, thus avoiding activation of the apoptotic pathway in sperm mitochondria and protecting mitochondrial structure and sperm function.

The role of Langerhans cells in epidermal homeostasis and pathogenesis of psoriasis

The skin is the main barrier between the human body and the outside world, which not only plays the role of a physical barrier but also functions as the first line of defence of immunology. Langerhans cells (LCs), as dendritic cells (DC) that play an important role in the immune system, are mainly distributed in the epidermis. This review focuses on the role of these epidermal LCs in regulating skin threats (such as microorganisms, ultraviolet radiation and allergens), especially psoriasis. Since human and mouse skin DC subsets share common ontogenetic characteristics, we can further explore the role of LCs in psoriatic inflammation.